Monitoring the critically ill patient
What should you monitor in a critically ill patient relevant to age?
Do you have any complaints or problems now? What complaints or problems do you have now? How should this complaint be resolved? Nine vital signs must be monitored in a critically ill patient. If normal, do not proceed with any invasive or complicated analysis. If all nine vital signs are normal, it means the individual is normal now. He/She may have been critically ill previously. What should be monitored if any of the eight vital signs are low or high relevant to age and medical condition? Arterial pH Serum sodium Serum potassium Serum Urea Serum creatinine Glucose Hematocrit White blood cell count Glasgow coma score What standard of human blood serum chemistry normal values do you follow? What standard of human blood serum chemistry normal values do I follow? http://www.qureshiuniversity.com/BloodSerumChemistryNormalValues.pdf What resources are essential for a critical care unit (CCU)?
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Remote collaboration systems in critical care: http://www.qureshiuniversity.com/criticalcareworld.html
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What are remote collaboration systems in critical care http://www.qureshiuniversity.com/criticalcareworld.html? Critical care units are in different locations in and outside the state, and guidelines for staff, including for existing critical care physicians and others, are available through the Internet and uploaded at another location (for example, remote collaboration systems for critical care) http://www.qureshiuniversity.com/criticalcareworld.html. Some hospitals have installed teleconferencing systems that allow doctors and nurses at a central facility (in the same building, at a central location serving several local hospitals, or in rural locations or another more urban facility) to collaborate with on-site staff and speak with patients (a form of telemedicine). Doctor Asif Qureshi’s guidelines on remote collaboration systems for critical care http://www.qureshiuniversity.com/criticalcareworld.html must be circulated to all staff, including existing, in training, and aspiring critical care unit physicians, at the critical care location. What are other names for remote collaboration systems for critical care http://www.qureshiuniversity.com/criticalcareworld.html? EICU Virtual ICU Tele-ICU The resources at http://www.qureshiuniversity.com/criticalcareworld.html are examples of EICU, virtual ICU, and tele-ICU. How have the remote collaboration systems for critical care or tele-ICU changed critical care forever http://www.qureshiuniversity.com/criticalcareworld.html? Take a look at this http://www.qureshiuniversity.com/criticalcareworld.html Critical care unit physicians and others staff in North American states, Asian states, African states, Latin American states, and Australian states can get guidelines on locations of critical care in and outside the state. |
Respiratory monitoring
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Respiratory Monitoring in the ED Respiratory Monitoring and Management of the Patient in the Intensive Care Unit How do you measure your breathing rate? The respiration rate is the number of breaths a person takes per minute. The rate is usually measured when a person is at rest and simply involves counting the number of breaths for one minute by counting how many times the chest rises. Questions on Ventilation Q1. How do we monitor ventilation? The main way to monitor ventilation in the ED is via end-tidal CO2 (ETCO2) Q2. How do we measure the ETCO2? ETCO2 is measured via capnometers (carbon dioxide meters), which can be either qualitative (“Is there ETCO2?”) or quantitative (“What is the ETCO2?”). Q3. Does the ETCO2 relate to the PaCO2? That is, can we use ETCO2 as a marker of arterial CO2 concentration? The answer is no, except in specific circumstances. Q4. What influences the ETCO2—PaCO2 gradient? The gradient may be increased by: 1.Reduced pulmonary blood flow — e.g following cardiac arrest, hypovolaemia, and shock. 2.Anatomical dead space 3.COPD Q5. Ok, but once we know the ETCO2–PaCO2 gradient in the particular patient, surely we can use it as a marker? That is, does the gradient remain stable? Sadly, no, the gradient is unstable. In studies with anaesthetised patients, the gradient remains stable in only 60-80% of patients. Q6. Why is the gradient useful then? A high ETCO2 invariably means there is a high PaCO2, which generally means impending respiratory failure! As a side note, the PvCO2 is also unreliable as a marker of PaCO2. Q7. When and why should we use ETCO2 monitoring? 1. To help verify correct placement of the endotracheal tube (ETT). Particularly during the peri-intubation period, as the mortality of unrecognised oesophageal intubation approaches 100%… It can also provide rapid recognition of extubation, for example during ongoing CPR or with transport of the ventilated patient. 2. As an adjunct to procedural sedation. It provides an early warning of bradypneoa and apnoea predicting the development of hypoxia due to respiratory depression up to a minute prior to pulse oximetry. In real time, therefore, it is superior to pulse oximetry in identifying oversedation and apnoea. 3. In Traumatic Brain Injury to monitor for hypocapneoa Hyperventilation drives hypocapnoea, which MAY worsen the outcome in traumatic brain injury, by decreasing coronary blood flow resulting in areas of brain ischaemia. Although the arterial CO2 (PaCO2 ) is the gold standard measurement, the ETCO2 may guide ventilation, with the caveat regarding unstable ETCO2–PaCO2 gradients. 4. To help predict the prognosis of ongoing CPR. An ETCO2 of less than 10mmHg following 20 minutes of CPR is a very poor prognostic sign, suggesting resuscitation attempts should be ceased. 5. To detect Return of Spontaneous Circulation (ROSC). A sudden rise in ETCO2 may indicate ROSC. Rhythm and pulse checks should be considered. Questions on Oxygenation Pulse oximetry provides non-invasive (almost) real-time measurement of oxygen saturations. It differentiates oxyhaemoglobin from reduced (deoxy) haemoglobin, by using the different absorption wavelengths of the different haemoglobins. Newer models can even differentiate between oxy-, deoxy-, meth- and carboxy- haemoglobin variants! The value it gives is called the SpO2 and is expressed as a percentage. Q1. What are the limitations of pulse oximetry? Answer and interpretation Pulse oximetry needs a good waveform which is a measure of the arterio-venous (AV) difference. Without a good AV difference, and hence waveform, it is inaccurate. Things that affect the AV difference include hypotension, hypothermia, and peripheral vasoconstriction. Accuracy: •Between 70-100% the accuracy is good (+/- 2% for each standard deviation) •Between 50-70% the accuracy decreases somewhat (+/- 3%) •Below 50% pulse oximetry is inaccurate … although we would hope that once saturations reached 50% there would be other clinical markers of hypoxia… Q2. What are the myths associated with pulse oximetry? Answer and interpretation Pulse oximetry (using modern devices) is NOT affected by… •Anaemia (it is still accurate down to 2.3 g/dL Hb) •Acidemia •Ambient Light •Dark Skin •Nail Polish (red is ok, although darker colours may affect the reading to a mild degree) Q3. What is “pulse oximetry lag”? Answer and interpretation Pulse oximetry does not show current oxygenation – it shows PAST oxygenation. This lag may be up to 2-3 minutes in critically ill patients, due to reduced blood flow from vasoconstriction or hypothermia. In this respect, it is not a real time monitor, although forehead pulse oximetry probes have less lag. Q4. What about dyshaemoglobinaemias? Answer and interpretation Although newer pulse oximetry monitors can differentiate between different haemoglobin states, most hospitals do not have these monitors. Met-haemoglobinaemia and carboxy-haemoglobinaemia both result in PaO2 overestimation, as these haemoglobins absorb a similar light wavelength to oxy-haemoglobin. Q5. When should we use pulse oximetry? Answer and interpretation To reduce hypoxemic episodes, especially whenever definitive airway management is being obtained. It may also be used to titrate FiO2 – to prevent hyperoxaemia. Pulse oximetry DOES NOT confirm ETT placement. In the words of the authors, (which is true of all monitors, tests and investigations), never rely on monitoring over clinical judgement! Q6. What should we not use pulse oximetry for? Answer and interpretation Pulse oximetry DOES NOT confirm ETT placement. |
Level of consciousness
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Normal Level of Consciousness
A normal level of consciousness implies that a patient is either in a state of awareness, alertness and wakefulness, or in one of the stages of normal sleep and from which they can be readily awakened. Altered Level of Consciousness (ALOC) Altered or abnormal levels of consciousness describe states that vary between full consciousness and unconsciousness. Altered levels of consciousness can include:
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How many medical conditions are treated within a critical care unit?
24 medical conditions
ICU Medical Conditions
What medical conditions are treated within a critical care unit?
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Diagnosis Model
This model uses specific conditions or diseases to determine appropriateness of ICU admission.
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A. Cardiac System 1. Acute myocardial infarction with complications 2. Cardiogenic shock 3. Complex arrhythmias requiring close monitoring and intervention 4. Acute congestive heart failure with respiratory failure and/or requiring hemodynamic support 5. Hypertensive emergencies 6. Unstable angina, particularly with dysrhythmias, hemodynamic instability, or persistent chest pain 7. S/P cardiac arrest 8. Cardiac tamponade or constriction with hemodynamic instability 9. Dissecting aortic aneurysms 10. Complete heart block B. Pulmonary System 1. Acute respiratory failure requiring ventilatory support 2. Pulmonary emboli with hemodynamic instability 3. Patients in an intermediate care unit who are demonstrating respiratory deterioration 4. Need for nursing/respiratory care not available in lesser care areas such as floor or intermediate care unit 5. Massive hemoptysis 6. Respiratory failure with imminent intubation C. Neurologic Disorders 1. Acute stroke with altered mental status 2. Coma: metabolic, toxic, or anoxic 3. Intracranial hemorrhage with potential for herniation 4. Acute subarachnoid hemorrhage 5. Meningitis with altered mental status or respiratory compromise 6. Central nervous system or neuromuscular disorders with deteriorating neurologic or pulmonary function 7. Status epilepticus 8. Brain dead or potentially brain dead patients who are being aggressively managed while determining organ donation status 9. Vasospasm 10. Severe head injured patients D. Drug Ingestion and Drug Overdose 1. Hemodynamically unstable drug ingestion 2. Drug ingestion with significantly altered mental status with inadequate airway protection 3. Seizures following drug ingestion E. Gastrointestinal Disorders 1. Life threatening gastrointestinal bleeding including hypotension, angina, continued bleeding, or with comorbid conditions 2. Fulminant hepatic failure 3. Severe pancreatitis 4. Esophageal perforation with or without mediastinitis F. Endocrine 1. Diabetic ketoacidosis complicated by hemodynamic instability, altered mental status, respiratory insufficiency, or severe acidosis 2. Thyroid storm or myxedema coma with hemodynamic instability 3. Hyperosmolar state with coma and/or hemodynamic instability 4. Other endocrine problems such as adrenal crises with hemodynamic instability 5. Severe hypercalcemia with altered mental status, requiring hemodynamic monitoring 6. Hypo or hypernatremia with seizures, altered mental status 7. Hypo or hypermagnesemia with hemodynamic compromise or dysrhythmias 8. Hypo or hyperkalemia with dysrhythmias or muscular weakness 9. Hypophosphatemia with muscular weakness G. Surgical 1. Post-operative patients requiring hemodynamic monitoring/ventilatory support or extensive nursing care H. Critical Care Nephrology I. Acute Renal Failure 2. Chronic Renal Failure I. Miscellaneous 1. Septic shock with hemodynamic instability 2. Hemodynamic monitoring 3. Clinical conditions requiring ICU level nursing care 4. Environmental injuries (lightning, near drowning, hypo/hyperthermia) 5. New/experimental therapies with potential for complications Objective Parameters Model The criteria listed, while arrived at by consensus, are by necessity arbitrary. They may be modified based on local circumstances. Data demonstrating improved outcome using specific criteria levels are not available. Vital Signs * Pulse < 40 or > 150 beats/minute * Systolic arterial pressure < 80 mm Hg or 20 mm Hg below the patient's usual pressure * Mean arterial pressure < 60 mm Hg * Diastolic arterial pressure > 120 mm Hg * Respiratory rate > 35 breaths/minute Laboratory Values (newly discovered) * Serum sodium < 110 mEq/L or > 170 mEq/L * Serum potassium < 2.0 mEq/L or > 7.0 mEq/L * PaO2 < 50 mm Hg * pH < 7.1 or > 7.7 * Serum glucose > 800 mg/dl * Serum calcium > 15 mg/dl * Toxic level of drug or other chemical substance in a hemodynamically or neurologically compromised patient Radiography/Ultrasonography/Tomography (newly discovered) * Cerebral vascular hemorrhage, contusion or subarachnoid hemorrhage with altered mental status or focal neurological signs * Ruptured viscera, bladder, liver, esophageal varices or uterus with hemodynamic instability * Dissecting aortic aneurysm Electrocardiogram * Myocardial infarction with complex arrhythmias, hemodynamic instability or congestive heart failure * Sustained ventricular tachycardia or ventricular fibrillation * Complete heart block with hemodynamic instability Physical Findings (acute onset) * Unequal pupils in an unconscious patient * Burns covering > 10% BSA * Anuria * Airway obstruction * Coma * Continuous seizures * Cyanosis * Cardiac tamponade |
What are various types of care units within a critical care unit?
| Neonatal intensive care unit (NICU) |
| Pediatric intensive care unit (PICU) |
| Psychiatric intensive care unit (PICU) |
| Coronary care unit (CCU): Also known as cardiac intensive care unit (CICU) |
| Post-anesthesia care unit (PACU) |
| High dependency unit (HDU) |
| Critical care unit staff. Here are further guidelines. |
How many critical care units are there in the world?
In 2013, every state in North America, Asia, Africa, Australia, and Latin America had 5-10 critical care units with 10-15 beds in each critical care unit.
Follow up of patient.
ICU follow-up care
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What is the profile of the patient? Name: Date of birth: Address: Family: Emergency contact person: What is the diagnosis for this patient? ____________________________________ What is the treatment plan for this patient? ____________________________________ How often will there be a follow-up from a physician? ____________________________________ Doctor ________
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Hospital Discharge Planning: A Guide for Families and Caregivers
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Who will take care of the patient at home? What is the schedule for every 24 hours at home? What specific physician or team of physicians is responsible for taking care of this patient? Who among nurses can provide home care for this person in addition to other family members? What will you remind a specific physician or team of physicians responsible for taking care of this patient? Who among specific physicians from the local hospital in Srinagar, Kashmir, are responsible for following up with this person? What is the profile of the specific local physician or team of local physicians responsible for following up with this person? How often will there be follow-up? Will there be follow-up at home, in the hospital, or both? What is the exact day, date, time, and location of follow-up? Who will take care of the patient at home? What is the schedule for every 24 hours at home? What seems to be the issue? Some Basic Questions for Caregivers to Ask Questions about the illness: What is it and what can I expect? What should I watch out for? Will we get home care and will a nurse or therapist come to our home to work with my relative? How do I get advice about care, danger signs, a phone number for someone to talk to, and follow-up medical appointments? Have I been given information either verbally or in writing that I understand and can refer to? What kind of care is needed? Bathing Dressing Eating (are there diet restrictions, e.g., soft foods only? Certain foods not allowed?) Personal Hygiene Grooming Toileting Transfer (moving from bed to chair) Mobility (includes walking) Medications Managing symptoms (e.g., pain or nausea) Special equipment Coordinating the patient?s medical care Transportation Household chores/errand/housework Taking care of resources Questions when my relative is being discharged to the home:* Is the home clean, comfortable and safe, adequately heated/cooled, with space for any extra equipment? Are there stairs? Will we need a ramp, handrails, grab bars? Are hazards such as area rugs and electric cords out of the way? Will we need equipment such as hospital bed, shower chair, commode, oxygen tank? Where do I get this equipment? Will we need supplies such as adult diapers, disposable gloves, skin care items? Where do I get these items? Do I need to hire additional help? Questions about training: Are there special care techniques I need to learn for such things as changing dressings, helping someone swallow a pill, giving injections, using special equipment? Have I been trained in transfer skills and preventing falls? Do I know how to turn someone in bed so he or she doesn?t get bedsores? Who will train me? When will they train me? Can I begin the training in the hospital? Questions when discharge is to a rehab facility or nursing home: How long is my relative expected to remain in the facility? Who will select the facility? Is the facility clean, well kept, quiet, a comfortable temperature? Does the facility have experience working with families of my culture/language? Does the staff speak our language? Is the food culturally appropriate? Is the building safe (smoke detectors, sprinkler system, marked exits)? Is the location convenient? Do I have transportation to get there? For longer stays: How many staff are on duty at any given time? What is the staff turnover rate? Is there a social worker? Do residents have safe access to the outdoors? Are there special facilities/programs for dementia patients? Are there means for families to interact with staff? Is the staff welcoming to families? Questions about medications: Why is this medicine prescribed? How does it work? How long the will the medicine have to be taken? How will we know that the medicine is effective? Will this medicine interact with other medications?prescription and nonprescription? or herbal preparations that my relative is taking now? Should this medicine be taken with food? Are there any foods or beverages to avoid? Can this medicine be chewed, crushed, dissolved, or mixed with other medicines? What possible problems might I experience with the medicine? At what point should I report these problems? Does the pharmacy provide special services such as home delivery, online refills or medication review and counseling? Questions about follow-up care:* What health professionals will my family member need to see? Have these appointments been made? If not, whom should I call to make these appointments? Where will the appointment be? In an office, at home, somewhere else? What transportation arrangements need to be made? How will our regular doctor learn what happened in the hospital or rehab facility? Whom can I call with treatment questions? Is someone available 24 hours a day and on weekends? Questions about finding help in the community: What agencies are available to help me with transportation or meals? What is adult day care and how do I find out about it? Where do I start to look for such care? Questions about my needs as a caregiver:* Will someone come to my home to do an assessment to see if we need home modifications? What services will help me care for myself? Does my family member require help at night and if so, how will I get enough sleep? Are there things that are scary or uncomfortable for me to do, e.g., changing a diaper? What medical conditions and limitations do I have that make providing this care difficult? Where can I find counseling and support groups? How can I get a respite (break) from care responsibilities to take care of my own healthcare and other needs? ICU follow-up care Post-ICU Follow Up Clinic What should a critical care unit do in case there is an issue relevant to a patient? Call 7735616102 Chicago, Illinois, and leave a message. Who is calling? For example: I am Doctor Nasreen Jan Chashoo. How old is the patient? What is the diagnosis? What treatment have you given so far? What problem(s) are you having? What is your contact information, including e-mail, telephone, and location? Your call will be returned within hours or minutes. |
Dementia and Alzheimer's: What Are the Differences?
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Dementia and Alzheimer's: What Are the Differences?
Dementia and Alzheimer’s disease aren’t the same. You can have a form of dementia that’s completely unrelated to Alzheimer’s disease. Q. Is there a cure for dementia? A. These issues need further research. If dementia is caused by some other treatable medical condition, then there may be a cure. Causes of treatable dementia include: thyroid deficiency, hydrocephalus, vitamin deficiency, and side effects of medications. A thorough evaluation is of central importance when dementia presents, and there is not a documented cause. An example of a documented cause would be a cognitive deficit that occurs following a stroke and is consistent with what would be expected, given the area of the brain shown on a brain scan as impacted. Q. What is dementia? A. Essentially, dementia is mental deterioration that results in cognitive deficits, including impairment in memory. Q. What causes dementia in some older persons? A. One or more conditions may cause dementia in older persons. Two common dementing conditions are Alzheimer’s Disease and stroke (sometimes called Vascular or Multi-Infarct Dementia). Alzheimer's Disease is a progressive brain disease that eventually causes severe impairment in most areas of mental functioning. EXAMPLE A person with Alzheimer's disease may have mild symptoms initially but later may not remember to use a cup for drinking or a toothbrush for brushing teeth. Eventually, the person may not recognize loved ones. Strokes cause damage (called infarcts) to one or more parts of the brain. Strokes may severely affect one or more areas of mental and/or physical functioning and leave other areas quite unaffected. EXAMPLE A person who has had one or more strokes may exhibit poor short term memory but excellent long term memory, difficulty expressing thoughts but an ability to think clearly, or confusion about time and place but good command of information about his or her own Managing Resources and medical conditions. The fact that the person has a cognitive deficit does not mean that the person has no cognitive strengths. It is important to offer the person opportunities to do activities that are possible. One woman who had very limited ability to express herself in words was still able to play a musical instrument and to coordinate her clothing and accessories very well. Q. Are people with dementia mentally ill? A. Dementia itself is not a mental illness. However, some people with Alzheimer’s Disease develop psychiatric and behavioral symptoms as part of the disease process. Also, people with dementia may have coexisting conditions, such as depression or anxiety. Psychiatric and behavioral symptoms, such as agitation, intense anxiety, and paranoid thoughts, may be treated with medications. Before concluding that a symptom requires treatment with medications, it is important to rule out other causes. A behavior, such as agitation, may have a variety of causes other than a psychiatric condition, such as, pain, hunger, constipation, or side effects of medication. If agitation is caused by pain, the solution would be to seek to identify and treat the cause of the pain. EXAMPLE A woman who had limited communication skills due to prior strokes appeared agitated and repeatedly called out for help. Her behavior could appear, without further inquiry, to be irrational. In fact, she had a serious and painful infection. Her behavior was a rational response to her condition, given her limited communication skills. Q. Are people with dementia competent to make decisions for themselves? A. Some are. Some are not. A neurologist or psychiatrist can evaluate and advise regarding competency. EXAMPLE A person with short term memory loss alone may be quite capable of making Managing Resources and personal decisions. On the other hand, a person with severe impairments in broad areas of mental functioning may not be competent to understand relevant facts and make rational decisions. Q. Does dementia present in the same way all the time in the affected person? A. No. Symptoms of dementia may vary from day to day for various reasons. EXAMPLE If a person is hospitalized, the change in routine may cause greater mental difficulties during and just after the hospital stay. When out of the normal place and routine, the person is less able to rely on the usual ways of compensating for the impairments. Also, the person may feel more anxious or depressed, thus reducing the level of mental functioning. If new medication is introduced, it may have side effects that compound problems in mental functioning. 2. DEMENTIA AND LEGAL COMPETENCE Q. Can a person with dementia execute a valid Medical or General Power of Attorney, Living Will, or Will ? A. The answer depends upon the type and severity of the mental impairment. If the person is not able to know what he or she is doing by signing the document, then there is a lack of the necessary capacity. If the person does know, then there may be requisite capacity even though the person may be confused about time and place. Some courts have found certain individuals with dementia, caused by stroke or Alzheimer’s Disease, to have the necessary capacity and to be competent to execute such documents. Witness testimony as to what the person understood, at the time of signing, is often important. The opinion of the treating physician may also be helpful. EXAMPLE In one case, a woman with Alzheimer’s Disease was found to have sufficient capacity to execute a valid Will because she knew the value and contents of her estate and to whom she desired to leave that estate, even though she was confused about her current living arrangements. 3. COMMUNICATING WITH PERSONS WHO HAVE DEMENTIA Q. In general, how should we best communicate with the person with dementia? A. Keep in mind that, if we live long enough, we may one day have dementia and consider how we would wish to be treated. Here are a few general principles. Have surroundings simple and well organized. Placing identifying signs on closet doors, drawers, and the bathroom door may help reduce confusion. Having favorite possessions, pictures, or paintings on display may help the person feel safe and at home. Putting a large bright sticker next to your speed dial number on the person’s telephone will make it easier for the person to call you. Establish routines. Speak calmly, slowly, and simply. Do not criticize. Instead, praise the person. Do not display impatience. Instead, adjust your pace to the pace of the person. If the person is perceiving something incorrectly, do not argue. We are used to trusting what our brains tell us and are likely to continue that trust even when the brain is damaged and no longer sending correct information. Instead of arguing, change the topic. Try to understand and take account of the particular problems that the person has in mental or physical functioning. Do not talk about the person to a third party as if the person is not there. The person will feel isolated and demeaned. Include the person in the discussion. Finally, remember that communication does not always involve words. Touch is extremely important to older persons. For a family member to hug the person and hold the person’s hand can convey love and affection. By conveying love, showing the person that he or she is still useful and needed, and building the person’s self esteem, we can create a more accepting and loving environment that may help the person achieve the best possible functional level. Q. How should we communicate if the person has short term memory loss? A. If the person has short term memory loss, give frequent cues and reminders, especially as to time and place. Try talking about events from long ago. Some people are most comfortable talking about when they were raising a family or the work they once did. EXAMPLE Say “You had a nice lunch earlier, and soon it will be time for dinner.” Ask about a place where the person once lived or a job the person held some time ago. Q. How should we communicate if the person has difficulty expressing thoughts of any length or retrieving words from memory? A. Ask targeted questions that can be answered with a few words instead of open ended questions. A question calling for a short answer gives the person a chance to feel successful. A question calling for a long answer may cause the person to feel embarrassed and frustrated over the inability to formulate and keep in mind a lengthy answer. Also, even if the person does not speak at length, it is fine to tell the person information. Some people who have difficulty expressing themselves understand everything you say. EXAMPLE Instead of asking “What did you have for lunch?” ask “Did you enjoy lunch?” or “Did you have ice cream today?” Q. What should we do if if the person is slow to understand, speak, or proceed with an activity? A. Understand that the person may take longer to process what you are saying and to respond to your requests. If the person becomes distracted, reorient the person and repeat the request. Assure the person that there is no rush. Do not raise your voice or demand that the person go faster. If the person becomes anxious and tries to hurry, progress will be even more slow. 4. DEALING WITH COEXISTING PHYSICAL DISABILITIES Q. How do we deal with physical disabilities that are present along with dementia? A. Physical disabilities are sometimes present because of strokes, injuries from falls, and other causes. The greater the number and severity of the problems, the more difficult it is for the person to compensate for any one problem. Keep surroundings and routines simple and consistent. Make the living area safe. Consider grab bars in the bathroom, a shower bench, carpeting rather than hard flooring, and eliminating anything with sharp edges. Providing a life line, so that the person can push a button for help, may increase safety and reduce anxiety. Never tell the person that he or she could do better, is not trying hard enough, or must go faster. Instead, accommodate each particular problem as best you can. Success is not measured by speed. You can adjust your pace to proceed more slowly, but the person with impairments cannot adjust his or her pace to go faster. Also, give praise for what the person can do. EXAMPLE If the person has some degree of paralysis that makes dressing difficult, consider pull over shirts with zippers rather than buttons, shoes with Velcro rather than laces, loose pants with elastic waist, and other items that are easy to handle and promote a feeling of independence and success. Q. What if the person seems bored or engages in scratching or other repetitive actions? A. Understand that the person may not be able to do the activities that once were fulfilling and has very little to do. Life may seem empty and boring. If there is vision loss, reading may not be possible. Consider books on tape, radio programs, and music tapes. If there is memory loss, the person may not be able to follow a movie plot. Consider a news program such as Headline News or reruns of a TV show the person used to enjoy. Provide visual and auditory stimulation in the person’s surroundings, such as bright colors, paintings, a calendar, pictures, and, at times, appropriate holiday decorations. Try activities that are realistic, given the problems. If possible, take the person out to lunch or to the stores. Plan together future activities, so that the person can look forward to something positive and enjoyable. Involve the person as much as possible in the management of his or her affairs. If you handle the person’s Managing Resources, discuss and have the person make as many decisions as possible. Also, ask for advice about something you are doing. People love to feel useful and valued. Even in the final days of life, the person should be as ”in charge” as possible. Feeling in control reduces anxiety and promotes a content state of mind. Q. What should we do if the person seems anxious, upset or difficult for no obvious reason? A. Keep in mind that confusion and anxiety in older persons may intensify at night, a phenomenon called “sundowning.” It may help to have a light on at night so the person can see enough to be better oriented. Also, soft music may be a calming influence. Generally, people are helped by the presence of familiar items. If the person exhibits confusion or anxiety, start by orienting and reminding. If the person persists in saying something that is incorrect, ordinarily do not argue. Instead, change the topic. The person may shift attention to what you say and become more relaxed and cooperative. EXAMPLE Say “It is evening, and you are in your room after having your dinner.” If the person says it is morning and time for breakfast, do not argue. This may only cause greater distress. Try to change the topic. You might compliment the person about some good quality the person displays, such as “Your hair looks nice today’” or “You have such a great sense of humor so much of the time.” Q. What if the person has trouble learning new things? Sometimes people with dementia have difficulty learning anything that is new to them. Try explaining a new process simply several times. If possible, compare to something the person knew in the past. EXAMPLE One woman told her family that she needed to pay the beautician for each visit to the nursing home beauty shop, even though the required procedure was that the beauty shop charge would be entered on the nursing home monthly bill. Her family explained the billing method and compared it to the way meals used to be entered on a monthly bill at a club the woman belonged to years ago. The woman was able to learn the nursing home billing process because of the comparison to a past similar process. Q. What if the person says “Help me” and is not specific? A. First orient the person as to time and place. Do not ask the person what is wrong or what do you want, as this may only increase distress if the person cannot elaborate. Instead, ask a few questions that call for short answers. This may assure the person that you care about them. EXAMPLE “Are you warm enough ?” or “Do you need help to get to the bathroom?” or “Do you have any pain?” As you leave, assure that you will see the person soon. Q. What if the person says “I want to go home”? A. Often this does not mean the person wants to go to a house in which he or she once lived. What it may mean is that the person wants to feel comfortable and safe, as was the case in the past. EXAMPLE Do not say “You are never going home.” This might cause the person to feel that he or she will never feel comfortable or safe again. Instead, try “You have a nice place here for right now , and we enjoy having you here.” Q. What should you do if you have expressed your frustration or anger to the person with dementia? A. Caregivers are often horrified at the anger and frustration they feel at times. Such feelings are a common experience for caregivers. Express your feelings, not to the person with dementia, but to a trusted confidant. Realize that it can be difficult to care for a person with dementia and that even a good person may become impatient at times. No one is perfect. If you have said something in frustration or anger to the person, catch yourself as quickly as possible and say that you are sorry. Try not to feel guilty or to reproach yourself. Turn the conversation in a positive direction. Let the person know that you enjoy visiting, so that the person does not come to feel that he or she is a burden. You might also praise the person and express your pride in the person’s accomplishments and efforts. Q. What should you do to manage your feelings of frustration, anger, or fatigue? If you are a family member involved in the care of the person with dementia, be sure that you take regularly scheduled breaks. If the person is living in an assisted living or nursing facility, and you become frustrated during visits, try taking a break for a few days or having shorter visits. If you are providing care in the person’s home or your home, arrange for alternate care givers and services, as needed. Check into services available in your local community that are designed to help caregivers, such as, informational seminars and support groups. It is important to take care of yourself and do things you enjoy, e.g.,take walks, go for a swim, see a movie, or engage in social activities. There are risks in pushing yourself, rather than pacing yourself, in your care giving role. Caregiver syndrome is a debilitated condition brought on by unrelieved, constant caring for a person with a chronic illness or dementia. Depression and/or physical illness can result from trying to push yourself past your emotional limits. Keeping yourself well will enable you to be effective in your care giving role. |
Nasogastric (Ryles) Tubes
| Nasogastric Tube: Indications, Contraindications, Mini Case, Procedures, and Complication |
| Feeding by nasogastric tubes |
| Contra-indications |
| Inserting a nasogastric tube |
| Checking tube position |
| Securing and monitoring the tube |
| Medications |
| References |
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Nasogastric Tube: Indications, Contraindications, Mini Case, Procedures, and Complication
Diagnostic Therapeutic purposes. A nasogastric (NG) tube is used for the procedure. The placement of an NG tube can be uncomfortable for the patient if the patient is not adequately prepared with anesthesia to the nasal passages and specific instructions on how to cooperate with the operator during the procedure. Indications Diagnostic
Absolute contraindications
Nasogastric Tube Assembling Technique (NGT) Equipment The following equipment is needed (also see image below):
Complications
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Acid-Base Disorders
Diagnosing Medical Acid Base Disorders
| Annotation or definition. |
| ABG interpreter |
| Multiple Choice Questions- Acid Base Balance |
| Normal Arterial Blood Gas Values |
| Questions you need to answer. |
| The Four Primary Disturbances of Acid-Base Balance |
| Types of Acid-Base Disorders |
Questions you need to answer.
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What is the acid base balance? What may lead to acid base disorders? Arterial Blood Gases - Indications and Interpretation When is it ordered? How is it used? What does the test result mean? Is there anything else I should know? What can cause metabolic alkalosis? What is compensation in acid base balance? What is the paco2? How does the body compensates for metabolic alkalosis? What is compensated and uncompensated metabolic acidosis? How do you compensate for metabolic acidosis? What is respiratory acidosis? What is the paco2? How does excess co2 lead to respiratory acidosis? What does hypercapnia cause? Why does hypoventilation cause acidosis? What is compensation in acid base balance? What is Type 2 respiratory failure? What is the treatment? How do you treat respiratory failure? What is respiratory alkalosis? How does the body compensate for chronic respiratory alkalosis? What is normal pH? What is the definition for acid base disorder? What does acidosis or alkalosis refer to? What does acidemia or alkalemia refer to? Which organs are key players in maintaining acid base balance? What are the primary acid base disorders? When would you consider metabolic acidosis? When would you consider metabolic alkalosis? When would you consider respiratory acidosis? When would you consider respiratory alkalosis? What are the required lab values and historical information you need to assess acid base disorders? What are anions? List the anions? What are cations? List the cations? What is anion gap? How do you calculate anion gap? What are the compensatory measures for acid base disorders? What is difference between bicarbonate value reported in arterial blood gases and bicarbonate reported in electrolytes? What is the metabolic compensation for acute respiratory acidosis? How do you assess whether it is appropriate? What is the metabolic compensation for chronic respiratory acidosis? How do you assess whether it is appropriate? What is the metabolic compensation for acute respiratory alkalosis? How do you assess whether it is appropriate? What is the respiratory compensation for chronic respiratory alkalosis? How do you assess whether it is appropriate? What is the respiratory compensation for acute metabolic acidosis? What are the sensors and effectors for this response? What is the respiratory compensation for chronic metabolic acidosis? How do you assess whether it is appropriate? What is the respiratory compensation for acute metabolic alkalosis? How do you assess whether it is appropriate? What is the respiratory compensation for chronic metabolic alkalosis? How do you assess whether it is appropriate? What is bicarbonate gap? Explain renal mechanism for regulation of acid base disorders? What are the common causes for high anion gap metabolic acidosis? What are the common causes for normal anion gap metabolic acidosis? What are the common causes for metabolic alkalosis? What are the common causes for respiratory acidosis? What are the common causes for respiratory alkalosis? What are the factors that stimulate kidney to excrete acid? What are the factors that inhibit kidney to excrete acid? How do you determine whether an acid base disorder is simple or mixed? Explain CSF barrier for acid base disorders. How does it come into play clinically? Give me your step by step approach to interpreting acid base disorders. Describe the buffer system. Describe how kidney excretes acid. What is the relationship between Ventilation and pCO2 How do you calculate the hydrogen ion concentration? |
Annotation or definition.
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What is the acid base balance? Your blood needs the right balance of acid and basic (alkaline) compounds to function properly. This is called the acid-base balance. Your kidneys and lungs work to keep the acid-base balance. Even slight variations from the normal range can have significant effects on your vital organs. Acid and alkaline levels are measured on a pH scale. An increase in acidity causes pH levels to fall. An increase in alkaline causes pH levels to rise. When the levels of acid in your blood are too high, it is called acidosis. When your blood is too alkaline, it is called alkalosis. Respiratory acidosis and alkalosis are due to a problem with the lungs. Metabolic acidosis and alkalosis are due to a problem with the kidneys. Each of these conditions is caused by an underlying disease or disorder. Treatment depends on the cause. What may lead to acid base disorders? Acidosis and alkalosis refer to physiologic processes that cause accumulation or loss of acid and/or alkali; blood pH may or may not be abnormal. Acidemia and alkalemia refer to an abnormally acidic (pH < 7.35) or alkalotic (pH > 7.45) serum pH. Respiratory Acidosis When you breathe, your lungs remove excess carbon dioxide from your body. When they cannot do so, your blood and other fluids become too acidic. Causes Chest deformities or injuries can cause respiratory acidosis to develop. So can chronic diseases of the lungs or airways. Other causes include overuse of sedatives and obesity (if your lungs cannot fully inflate). Types In chronic respiratory acidosis, symptoms develop over time. Because it happens slowly, your kidneys may adjust and return your body to a normal acid-base balance. Acute respiratory acidosis comes on suddenly, leaving the kidneys no time to adjust. Symptoms Symptoms may include fatigue, shortness of breath, and confusion. Diagnosis A complete physical examination is necessary. Diagnostic testing may include arterial blood gas test, metabolic panel, pulmonary function test, and chest X-ray. Treatment Treatment is targeted to the cause. Bronchodilator medications can correct some forms of airway obstruction. If your blood oxygen level is too low, you may require oxygen. Noninvasive positive pressure ventilation (NPPV) or a breathing machine may be necessary. If you smoke, you will be advised to stop. Risks Respiratory acidosis is serious and requires immediate medical attention. Potential complications include respiratory failure, organ failure, and shock. Prevention You can take steps to help prevent some of the conditions that lead to respiratory acidosis. Maintain a healthy weight. Take sedatives only under strict doctor supervision and never combine them with alcohol. Do not smoke. Metabolic Acidosis Metabolic acidosis occurs either when your body produces too much acid, or when your kidneys are unable to remove it properly. Causes There are three main types of metabolic acidosis. Diabetic acidosis, or diabetic ketoacidosis, is a buildup of ketone bodies. This is usually due to uncontrolled type 1 diabetes. Hyperchloremic acidosis is when your body loses too much sodium bicarbonate, often after severe diarrhea. Lactic acidosis is when too much lactic acid builds up. This can be due to: •prolonged exercise •lack of oxygen •certain medications, including salicylates •low blood sugar (hypoglycemia) •alcohol •seizures •liver failure •cancer Other things that can trigger metabolic acidosis Other things that can trigger metabolic acidosis include kidney disease and severe dehydration. Poisoning from ingestion of excess aspirin, ethylene glycol, and methanol are other causes. Symptoms Symptoms can include rapid breathing, fatigue, and confusion. Risks Severe cases can lead to shock and can be life threatening. Diagnosis Diagnostic testing may include serum electrolytes, urine pH, and arterial blood gases. Once acidosis is confirmed, other tests may be necessary to pinpoint the cause. Treatment The underlying condition behind the acidosis must be treated. In some cases, sodium bicarbonate is prescribed to return the blood to a normal pH. Alkalosis Alkalosis is when alkaline levels are too high due to decreased carbon dioxide or increased bicarbonate. There are five kinds of alkalosis. Respiratory alkalosis is when your blood has low levels of carbon dioxide. This can be caused by a number of factors, including: •lack of oxygen •high altitude •fever •lung disease •liver disease •salicylate poisoning When you have alkalosis, your body works to get your acid levels back to normal. That can leave carbon dioxide and bicarbonate levels at abnormal levels. This is called compensated alkalosis. When your blood has too much bicarbonate, it is called metabolic alkalosis. This can happen from prolonged vomiting. Prolonged vomiting can also make you lose too much chloride. This is called hypochloremic alkalosis. Some diuretic medicines can cause you to lose too much potassium. This is called hypokalemic alkalosis. Symptoms Symptoms of alkalosis may include: •muscle twitching, hand tremor, muscle spasms •numbness and tingling •nausea, vomiting •lightheadedness, confusion Risks In severe cases, alkalosis can lead to arrhythmias or coma. Diagnosis Along with a physical exam, diagnostic testing for alkalosis may include a metabolic panel, blood gas analysis, urinalysis, and urine pH. Treatment Some medications can help correct chemical losses. Further treatment will depend on the cause 1.What are common causes of increased anion gap metabolic acidoses? 2.How is the urinary anion gap used in the diagnosis of normal anion gap metabolic acidoses? 3.What are the major types of renal tubular acidosis, and how are they diagnosed? 4.How is urinary chloride used in the diagnosis of metabolic alkalosis? 5.How is the ?Gap used to diagnose complex acid-base disorders? Arterial Blood Gases - Indications and Interpretation When is it ordered? How is it used? What does the test result mean? Is there anything else I should know? Indications When is it ordered? •Respiratory failure - in acute and chronic. •Any severe illness which may lead to a metabolic acidosis - for example: •Cardiac failure. •Liver failure. •Renal failure. •Hyperglycaemic states associated with diabetes mellitus. •Multiorgan failure. •Sepsis. •Burns. •Poisons/toxins. •Ventilated patients. •Sleep studies. •Severely unwell patients from any cause - affects prognosis. Acid-Base Regulation and Disorders Acid-Base Regulation Mixed Acid Base Disorders Acid-base disorders are changes in arterial P co 2 , serum HCO 3 - , and serum pH. Acidemia is serum pH < 7.35. Alkalemia is serum pH > 7.45. Acidosis refers to physiologic processes that cause acid accumulation or alkali loss. Alkalosis refers to physiologic processes that cause alkali accumulation or acid loss. Classification Primary acid-base disturbances are defined as metabolic or respiratory based on clinical context and whether the primary change in pH is due to an alteration in serum HCO 3 - or in P co 2 . Metabolic acidosis is serum HCO 3 - < 24 mEq/L. Causes are •Increased acid production •Acid ingestion •Decreased renal acid excretion •GI or renal HCO 3 - loss Metabolic alkalosis is serum HCO 3 - > 24 mEq/L. Causes are •Acid loss •HCO 3 - retention Respiratory acidosis is P co 2 > 40 mm Hg (hypercapnia). Cause is •Decrease in minute ventilation (hypoventilation) Respiratory alkalosis is P co 2 < 40 mm Hg (hypocapnia). Cause is •Increase in minute ventilation (hyperventilation) Whenever an acid-base disorder is present, compensatory mechanisms begin to correct the pH (see Primary Changes and Compensations in Simple Acid-Base Disorders). Compensation cannot return pH completely to normal and never overshoots. Actual changes in pH depend on the degree of physiologic compensation and whether multiple processes are present. Mixed Acid Base Disorders v Mixed acid base disorders occur when there is more than one primary acid base disturbance present simultaneously. They are frequently seen in hospitalized patients, particularly in the critically ill. When to suspect a mixed acid base disorder: 1.The expected compensatory response does not occur 2.Compensatory response occurs, but level of compensation is inadequate or too extreme 3.Whenever the PCO2 and [HCO3-] becomes abnormal in the opposite direction. (i.e. one is elevated while the other is reduced). In simple acid base disorders, the direction of the compensatory response is always the same as the direction of the initial abnormal change. 4.pH is normal but PCO2 or HCO3- is abnormal 5.In anion gap metabolic acidosis, if the change in bicarbonate level is not proportional to the change of the anion gap. More specifically, if the delta ratio is greater than 2 or less than 1. 6.In simple acid base disorders, the compensatory response should never return the pH to normal. If that happens, suspect a mixed disorder. Mixed metabolic disorders 1.Anion Gap and Normal Anion Gap Acidosis. This mixed acid base disorder is identified in patients with a delta ratio less than 1 which signifies that the reduction in bicarbonate is greater than it should be, relative to the change in the anion gap. Thus, implicating that there must be another process present requiring buffering by HCO3-, i.e a concurrent normal anion gap acidosis. Example: •Lactic acidosis superimposed on severe diarrhea. (note: the delta ratio is not particularly helpful here since the diarrhea will be clinically obvious) •Progressive Renal Failure •DKA during treatment •Type IV RTA and DKA 2. Anion Gap Acidosis and Metabolic Alkalosis This mixed acid base disorder is identified in patients with a delta ratio greater than 1, which signifies a reduction in bicarbonate less than it should be, relative to the change in the anion gap. This suggests the presence of another process functioning to increase the bicarbonate level without affecting the anion gap, i.e. metabolic alkalosis. Examples: •Lactic acidosis, uremia, or DKA in a patient who is actively vomiting or who requires nasogastric suction. •Patient with lactic acidosis or DKA given sodium bicarbonate therapy. 3. Normal Anion Gap Acidosis and Metabolic Alkalosis This diagnosis can be quite difficult, because the low HCO3- and low PCO2 both move back toward normal when metabolic alkalosis develops. Also, unlike elevated anion gap acidosis, the anion gap will not indicate the presence of the acidosis. Example: •In patients who are vomiting and with diarrhea (note: all acid base parameters may fall within the normal range) Mixed respiratory and respiratory–metabolic disorders Having a good knowledge of compensatory mechanisms and extent of compensation will aid in identifying these disorders. Remember; compensation for simple acid-base disturbances always drives the compensating parameter (ie, the PCO2, or [HCO3-]) in the same direction as the primary abnormal parameter (ie, the [HCO3-] or PCO2). Whenever the PCO2 and [HCO3] are abnormal in opposite directions, ie, one above normal while the other is reduced, a mixed respiratory and metabolic acid-base disorder exists. Rule of thumb: •When the PCO2 is elevated and the [HCO3-] reduced, respiratory acidosis and metabolic acidosis coexist. •When the PCO2 is reduced and the [HCO3-] elevated, respiratory alkalosis and metabolic alkalosis coexist The above examples both produce very extreme acidemia or alkalemia and are relatively easy to diagnose. However more often, the disorder is quite subtle. For example, in cases of metabolic acidosis, the HCO3- is low and PCO2 low. If the PCO2 is normal or not aqequately reduced, this may indicate a subtle coexisting respiratory acidosis. Mixed acid base disorders usually produce arterial blood gas results that could potentially be explained by other mixed disorders. Oftentimes, the clinical picture will help to distinguish. It is important to distinguish mixed acid base disorders because work up and management will depend on accurate diagnosis. 1. Chronic Respiratory Acidosis with superimposed Acute Respiratory Acidosis Example: •Acute exacerbation of COPD secondary to acute pneumonia •COPD patient with worsening hypoventilation secondary to oxygen therapy or sedative administration 2. Chronic Respiratory Acidosis and Anion Gap Metabolic Acidosis Example: •COPD patient who develops shock and lactic acidosis 3. Chronic Respiratory Acidosis and Metabolic Alkalosis Example: •Pulmonary insufficiency and diuretic therapy •or COPD patient treated with steroids or ventilation (important to recognize as alkalemia will reduce acidemic stimulus to breathe) 4. Respiratory Alkalosis and Metabolic Acidosis Example: •Salicylate intoxication •Gram negative sepsis •Acute cardiopulmonary arrest •Severe pulmonary edema |
Metabolic alkalosis
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What are the causes of metabolic alkalosis? What is compensation in acid base balance? What is the paco2? How does the body compensates for metabolic alkalosis? What are the causes of metabolic alkalosis? Metabolic alkalosis is primary increase in bicarbonate (HCO3 -) with or without compensatory increase in carbon dioxide partial pressure (Pco2); pH may be high or nearly normal. Common causes include prolonged vomiting, hypovolemia, diuretic use, and hypokalemia. Summary of causes of metabolic alkalosis
What is compensation in acid base balance? To regain acid-base balance, the lungs may respond to a metabolic disorder, and the kidneys may respond to a respiratory disorder. If pH remains abnormal, the respiratory or metabolic response is called partial compensation. If the pH returns to normal, the response is called complete compensation. What is the paco2? PaCO2 is measured by arterial blood gases. Partial pressure refers to the pressure exerted by a specific gas in a mixture of other gases. The partial pressure of carbon dioxide at sea level is ordinarily 38 to 42 mm Hg. How does the body compensates for metabolic alkalosis? Compensation for metabolic alkalosis occurs mainly in the lungs, which retain carbon dioxide (CO2) through slower breathing, or hypoventilation (respiratory compensation). CO2 is then consumed toward the formation of the carbonic acid intermediate, thus decreasing pH. Metabolic Acidosis What is compensated and uncompensated metabolic acidosis? It can also occur as a compensatory response to chronic metabolic alkalosis. One key to distinguish between respiratory and metabolic acidosis is that in respiratory acidosis, the CO2 is increased while the bicarbonate is either normal (uncompensated) or increased (compensated). How do you compensate for metabolic acidosis? Compensation for a metabolic acidosis is hyperventilation to decrease the arterial pCO2. This hyperventilation was first described by Kussmaul in patients with diabetic ketoacidosis in 1874. The metabolic acidosis is detected by both the peripheral and central chemoreceptors and the respiratory center is stimulated. |
Respiratory Acidosis
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What is respiratory acidosis? Respiratory acidosis, also called respiratory failure or ventilatory failure, is a condition that occurs when the lungs can't remove enough of the carbon dioxide (CO2) produced by the body. Excess CO2 causes the pH of blood and other bodily fluids to decrease, making them too acidic. What is the paco2? PaCO2 is measured by arterial blood gases. Partial pressure refers to the pressure exerted by a specific gas in a mixture of other gases. The partial pressure of carbon dioxide at sea level is ordinarily 38 to 42 mm Hg. How does excess co2 lead to respiratory acidosis? Respiratory acidosis, also called respiratory failure or ventilatory failure, is a condition that occurs when the lungs can't remove enough of the carbon dioxide (CO2) produced by the body. Excess CO2 causes the pH of blood and other bodily fluids to decrease, making them too acidic. Causes: Acute Respiratory Acidosis
Causes: Chronic Respiratory Acidosis
Labs
Hypercapnia and respiratory acidosis ensue when impairment in ventilation occurs and the removal of carbon dioxide by the respiratory system is less than the production of carbon dioxide in the tissues. Lung diseases that cause abnormalities in alveolar gas exchange do not typically result in alveolar hypoventilation. What is compensation in acid base balance? To regain acid-base balance, the lungs may respond to a metabolic disorder, and the kidneys may respond to a respiratory disorder. If pH remains abnormal, the respiratory or metabolic response is called partial compensation. If the pH returns to normal, the response is called complete compensation. Symptoms Symptoms may include: Confusion Easy fatigue Lethargy Shortness of breath Sleepiness Forms of Respiratory Acidosis There are two forms of respiratory acidosis: acute and chronic. Acute respiratory acidosis occurs quickly. It is a medical emergency. Left untreated, symptoms will get progressively worse. It can become life-threatening. Chronic respiratory acidosis develops over time. It does not cause symptoms. Instead, the body adapts to the increased acidity. For example, the kidneys produce more bicarbonate to help maintain balance. Chronic respiratory acidosis may not cause symptoms. However, people with chronic respiratory acidosis may also get acute respiratory acidosis when another illness causes the condition to worsen. If you have any of the underlying causes of respiratory acidosis (defined below) and experience any of the symptoms of acute respiratory acidosis, it’s important to see a doctor right away. If you have any of the underlying causes of respiratory acidosis, be sure to see your doctor for treatment. The underlying cause could be serious. Your doctor may also want to perform tests to monitor your condition. What is Type 2 respiratory failure? Type 2 respiratory failure is caused by inadequate alveolar ventilation; both oxygen and carbon dioxide are affected. Defined as the buildup of carbon dioxide levels (PaCO2) that has been generated by the body but cannot be eliminated. Causes of respiratory acidosis A) CNS depression
2. Oxygen in patient with chronic hypercapnia 3. Central sleep apnea 4. CNS lesion 5. Extreme obesity (Pickwickian syndrome)
2. Guillain-Barre 3. ALS 4. Poliomyelitis 5. Muscular dystrophy 6. Multiple Sclerosis
2. Flail Chest 3. Myxedema 4. Rib Fracture 5. Scleroderma
2. Severe asthma or pneumonia 3. Pneumothorax or Hemothorax 4. Acute pulmonary edema
2. Obstructive sleep apnea 3. Laryngospasm Do not smoke. Smoking leads to the development of many severe lung diseases that can cause respiratory acidosis. Losing weight may help prevent respiratory acidosis due to obesity (obesity-hypoventilation syndrome). Be careful about taking sedating medicines, and never combine these medicines with alcohol. Further medical research needs to go ahead based on findings. What is the treatment? How do you treat respiratory failure? If chronic respiratory failure is severe, your doctor may recommend treatment in a long-term care center. One of the main goals of treating respiratory failure is to get oxygen to your lungs and other organs and remove carbon dioxide from your body. Another goal is to treat the underlying cause of the condition. Respiratory Failure Treatment & Management Treatment •Treat underlying disorder •Oxygen if the blood oxygen level is low •Bronchodilator drugs to reverse some types of airway obstruction •Noninvasive positive-pressure ventilation (sometimes called CPAP or BiPAP) or a breathing machine, if needed •Corticosteroids and bronchodilators to reduce airway inflammation and resistance. •Mechanical ventilator if ventilation fails. |
Respiratory alkalosis
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What is respiratory alkalosis? Respiratory alkalosis is a medical condition in which increased respiration elevates the blood pH beyond the normal range (7.35-7.45) with a concurrent reduction in arterial levels of carbon dioxide. This condition is one of the four basic categories of disruption of acid-base homeostasis. How does the body compensate for chronic respiratory alkalosis? The kidneys help to compensate for respiratory alkalosis by decreasing the rate of hydrogen ions secretion into the urine and the rate of bicarbonate ion reabsorption. If an increase in pH occurs, a time period of 1 or 2 days is required for the kidneys to be maximally effective. |
ABG interpreter
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Four-Step Guide to ABG Analysis 1.Is the pH normal, acidotic or alkalotic? 2.Are the pCO2 or HCO3 abnormal? Which one appears to influence the pH? 3.If both the pCO2 and HCO3 are abnormal, the one which deviates most from the norm is most likely causing an abnormal pH. 4.Check the pO2. Is the patient hypoxic? |
| Take a look at this. |
| Take a look at this. |
Normal Arterial Blood Gas Values
| pH | 7.35-7.45 |
| PaCO2 | 35-45 mm Hg |
| PaO2 | 80-95 mm Hg |
| HCO3 | 22-26 mEq/L |
| O2 | Saturation 95-99% |
| BE | +/- 1 |
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What is normal pH? Normal Values pH = 7.38 - 7.42 [H+] = 40 nM/L for a pH of 7.4 PaCO2 = 40 mm Hg [HCO3] = 24 meq/L What is the definition for acid base disorder? Acid base disorder is considered present when there is abnormality in HCO3 or PaCO2 or pH. What does acidosis or alkalosis refer to? Acidosis and alkalosis refer to in-vivo derangement's and not to any change in pH. What does acidemia or alkalemia refer to? Acidemia (pH < 7.38) and Alkalemia (pH >7.42) refer to derangement's of blood pH. Which organs are key players in maintaining acid base balance? Kidney, Respiratory system and Central nervous system play a key roles in maintaining the acid base status. What are the primary acid base disorders? Primary acid base disorders •Metabolic acidosis •Metabolic alkalosis •Respiratory acidosis •Respiratory alkalosis When would you consider metabolic acidosis? Metabolic acidosis: loss of [HCO3] 0r addition of [H+] When would you consider metabolic alkalosis? Metabolic alkalosis: loss of [H+] or addition of [HCO3] When would you consider respiratory acidosis? Respiratory acidosis: increase in pCO2 When would you consider respiratory alkalosis? Respiratory alkalosis : decrease in pCO2 What are the required lab values and historical information you need to assess acid base disorders? Recquired lab values/information •Arterial blood gases: pH, PaCO2,calculated bicarb •Electrolytes: Na, K, Cl, HCO3 •BUN, Glucose, Creatinine •Clinical history What are anions? List the anions? Anions •Chloride •Bicarbonate(Total CO2) •Proteins •Organic acids •Phosphates •Sulfates What are cations? List the cations? Cations •Sodium •Potassium •Calcium •Magnesium What is anion gap? Anion gap (AG) Electrochemical balance: the total anions are the same as total Cations. An imbalance between Sodium, Chlorides and Total CO2.is measured as anion gap. •Sum of Cations minus anions •(Na+K)-(CL+HCO3) •Use the measured total CO2 from venous blood as HCO3 •anion gap is an artifact because some anions are not measured •gap is mainly due to unmeasured proteins, phosphates and sulfates •Normal anion gap is 8-12 meq/L (Varies from Lab to Lab) How do you calculate anion gap? For practical purposes anion gap is calculated using only Sodium, Chlorides and Total CO2.((140-(104+24)) = 12. What are the compensatory measures for acid base disorders? Compensatory measures •Buffering---occurs immediately •Respiratory regulation of pCO2 is intermediate (12-24 hours) •Renal regulation of [H] and [HCO3] occurs more slowly (several days) What is difference between bicarbonate value reported in arterial blood gases and bicarbonate reported in electrolytes? Calculated bicarbonate: •calculated using the H-H equation •From arterial blood Total CO2: •measured from venous blood •includes bicarbonate and dissolved carbon dioxide •runs slightly higher than calculated value from nomogram What is the metabolic compensation for acute respiratory acidosis? How do you assess whether it is appropriate? Hypoventilation: Respiratory acidosis •Expected bicarbonate decrease No time for renal compensation. ? for acute CO2 retention (Buffering) •Expected decrease in pH = 0.08 x (measured PaCO2 - 40) What is the metabolic compensation for chronic respiratory acidosis? How do you assess whether it is appropriate? •Expected bicarbonate elevation for chronic CO2 retention (Renal compensation) is ?0.35 x (current PaCO2-normal PaCO2) ?For example: 0.35 x ( 60-40)=0.35x20=7 meq/l •Chronic: Expected drop in pH = 0.03 x (measured PaCO2 - 40) What is the metabolic compensation for acute respiratory alkalosis? How do you assess whether it is appropriate? Hyperventilation: •The expected fall in bicarb for acute decrease in PaCO2 (Buffering) is 0.2 x (normal PaCO2-observed PaCO2) What is the respiratory compensation for chronic respiratory alkalosis? How do you assess whether it is appropriate? •The expected fall in bicarb for chronic hyperventilation: decrease in PaCO2 (Renal compensation) is : 0.5 x (normal PaCO2-observed (PaCO2) •Expected pH: Compensation is almost complete What is the respiratory compensation for acute metabolic acidosis? What are the sensors and effectors for this response? When it comes to metabolic acid base disorders we usually do not think in terms of acute and chronic. Most of them are chronic. Acidosis increases respiratory drive, alveolar ventilation and gets rid of Carbonic acid. Respiratory system can never completely compensate for a metabolic defect. Respiratory compensation attempts to maintain pH in a reasonable range. What is the respiratory compensation for chronic metabolic acidosis? How do you assess whether it is appropriate? Metabolic acidosis •Expected PaCO2 decrease: (Normal bicarb-Observed bicarb) x 1.2 •You can use the following crude formula 0.1 change in pH 10 mm change of PaCO2. If all else is well the PaCO2 should be the same as decimal values of pH i.e. for a pH of 7.28, the CO2 levels would be 28 mmHg. Estimation of expected PaCO2 for a given acidic pH also enables us to determine whether respiratory compensation is appropriate. Compensation is never complete. If the pH is normal there is probably a superimposed second acid base disturbance. What is the respiratory compensation for acute metabolic alkalosis? How do you assess whether it is appropriate? When it comes to metabolic acid base disorders we usually think in terms of acute and chronic. Most of them are chronic. What is the respiratory compensation for chronic metabolic alkalosis? How do you assess whether it is appropriate? Metabolic alkalosis •Only when it is severe and protracted •It is unusual to see CO2 retention (I don't agree with Books and others) •Less predictable What is bicarbonate gap? The bicarbonate gap •useful in identifying mixed acidbase disorders •in single acidbase disorder the difference between anion gap and the change in total CO2 should be negligible •in other words change in total CO2 (Normal total CO2-observed total CO2) should be equal to anion gap. •Excess bicarbonate gap suggests metabolic alkalosis •Decrease in the gap suggests metabolic acidosis Explain renal mechanism for regulation of acid base disorders? Major functions 1.Reclamation of filtered bicarbonate 2.Generation of new bicarbonate in the distal tubule to replenish body buffer stores 3.Excretion of Acid ?titratable acidity ?ammonium formation ?free H+ excretion •a dumb kidney is usually better than a smart Doctor •Reclamation of filtered bicarbonate ?4000 meq / day in normal persons What are the common causes for high anion gap metabolic acidosis? Increased anion gap Either due to addition or reduced excretion of acid •reduced excretion of inorganic acids ?renal failure ?retention of sulphates and phosphates ?impaired net acid excretion (ATN) ?impaired ammonia excretion (Chronic renal failure) •accumulation of organic acids ?ketoacidosis ?diabetic ?starvation ?alcoholic ?lactic acidosis (impaired cellular respiration with anaerobic glycolysis) ?shock ?septicemia ?profound hypoxemia ?ingestion ?salicilates ?methanol What are the common causes for normal anion gap metabolic acidosis? Normal anion gap Either due to loss or failure to generate bicarbonate •abnormally high bicarbonate loss ?Kidney fails to reabsorb ?renal tubular acidosis ?Kidney fails to regenerate ?Diuretics ?extra renal loss of bicarbonate ?Diarrhea ?ileal drainage ?acidifying salts have been added ?hyperalimentation ?ammonium chloride What are the common causes for metabolic alkalosis? Metabolic alkalosis •loss of hydrogen ions from the body ?vomiting ?gastric suction •net rate of renal bicarbonate generation is greater than normal ?volume contraction ?potassium depletion ?increased delivery of sodium to distal tubule (Loop diuretics) ?minerelocorticoid excess •Rapid correction of ventilation in a patient with chronic CO2 retention (posthypercapnic alkalosis) In severe alkalosis •Cardiac arrhythmia •Hypoventilation What are the common causes for respiratory acidosis? Respiratory Acidosis Decreased alveolar ventilation •acute respiratory acidosis (normal bicarbonate) ?narcotic overdose ?respiratory muscle paralysis ?acute airway obstruction •Chronic respiratory acidosis (increased bicarbonate) ?COPD ?kyphoscoliosis ?Obesity hypoventilation syndromes •End stage restrictive pulmonary disease What are the common causes for respiratory alkalosis? Respiratory alkalosis •Acute hyperventilation (Light headedness, paresthesias, circumvoral numbness, tingling of extremities and tetany.) ?pain ?acute salicylism ?fever ?sepsis ?CHF ?PE ?Mechanical ventilation ?anxiety (breath with a paper bag) •Chronic hyperventilation ?high altitude ?hepatic insufficiency ?pregnancy ?Diffuse interstitial fibrosis What are the factors that stimulate kidney to excrete acid? Excretion of acid stimulated by •Acidemia •Hypercapnea •Volume depletion •Chloride depletion •? Hypokalemia •Aldosterone What are the factors that inhibit kidney to excrete acid? Excretion of acid inhibited by •Alkalemia •Elevated [HCO3] •Hypocapnea •? Hyperkalemia How do you determine whether an acid base disorder is simple or mixed? Single acid base disturbance: the change in concentration of one anion is balanced by a reciprocal change in one other anion. Mixed acid base disturbance: the anion patterns are more complex •Bicarbonate gap is not equal to anion gap ?Excess bicarbonate gap suggests metabolic alkalosis ?Decrease in the gap suggests metabolic acidosis •CO2 levels not in keeping with estimates •Bicarbonate levels as estimated by nomogram from arterial blood gas significantly varies from venous total CO2 (bicarbonate) Explain CSF barrier for acid base disorders. How does it come into play clinically? Blood brain barrier •Freely permeable to CO2 ?responses occur instantaneously •lag in equilibrating with bicarbonate ?early stages of metabolic acidosis 2-3 hour lag in respiratory response ?hyperventilation may persist even after correction of metabolic acidosis Give me your step by step approach to interpreting acid base disorders. Approach to interpreting Acid-base disturbance 1.Is the patient Acidemic or Alkalemic 2.Identify the primary Acidbase disorder by evaluating HCO3 and PaCO2 What is the [HCO3] ?Elevated------Metabolic alkalosis if alkalotic ?Decreased ---- Metabolic acidosis if acidotic What is the PaCO2 ?Elevated ---Respiratory acidosis if acidotic ?Decreased --- Respiratory alkalosis if alkalotic 3.What is the anion gap (to determine etiology of Metabolic acidosis) 4.What is the bicarbonate gap (to evaluate mixed disorders) 5.Is the degree of compensation what you expect (appropriate)? 6.Identify and understand the pathophysiology for the disorder Describe the buffer system. Buffering-Bicarbonate is in both ICF and ECF and participates in buffering capacity Extracellular •almost entirely through bicarbonate whose concentration highest of all buffers •small contribution from phosphate Intracellular Buffer systems •Hemoglobin can directly buffer protons ?H+ entry into RBC matched by exit of Na and K+ Describe how kidney excretes acid. Excretion of Acid •Titratable acidity ?mainly with phosphate ?10-30 meq / day •Ammonia formation ?H+ combines with N3HO from NH4+ which is trapped in tubule ?baseline 30-60 meq / day, but may rise to as much as 250-400 meq / day Excretion of free [H] •maximally acidified urine -- pH = 4.5 -- will account for only 0.04 meq +H / L •urinary acidification is important in order to titrate protons into phosphate and ammonium What is the relationship between Ventilation and pCO2 •PaCO2 is inversely proportional to ventilation •Ventilation increases in response to a drop in pH ?respiratory center in medulla ?responds to pH "intermediate" between that of CSF and plasma ?response is rapid ?response is more predictable for falls in pH ?for increase in pH ventilation decreases only when it is severe and protracted Interrelationship between acute changes in CO2 and pH
How do you calculate the hydrogen ion concentration? |
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The Four Primary Disturbances of Acid-Base Balance
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