- •ICU Protocols
- •Preface
- •Acknowledgments
- •Contents
- •Contributors
- •1: Airway Management
- •Suggested Reading
- •2: Acute Respiratory Failure
- •Suggested Reading
- •Suggested Reading
- •Website
- •4: Basic Mechanical Ventilation
- •Suggested Reading
- •Suggested Reading
- •Websites
- •Suggested Reading
- •Websites
- •7: Weaning
- •Suggested Reading
- •8: Massive Hemoptysis
- •Suggested Reading
- •9: Pulmonary Thromboembolism
- •Suggested Reading
- •Suggested Reading
- •Websites
- •11: Ventilator-Associated Pneumonia
- •Suggested Readings
- •12: Pleural Diseases
- •Suggested Reading
- •Websites
- •13: Sleep-Disordered Breathing
- •Suggested Reading
- •Websites
- •14: Oxygen Therapy
- •Suggested Reading
- •15: Pulse Oximetry and Capnography
- •Conclusion
- •Suggested Reading
- •Websites
- •16: Hemodynamic Monitoring
- •Suggested Reading
- •Websites
- •17: Echocardiography
- •Suggested Readings
- •Websites
- •Suggested Reading
- •Websites
- •19: Cardiorespiratory Arrest
- •Suggested Reading
- •Websites
- •20: Cardiogenic Shock
- •Suggested Reading
- •21: Acute Heart Failure
- •Suggested Reading
- •22: Cardiac Arrhythmias
- •Suggested Reading
- •Website
- •23: Acute Coronary Syndromes
- •Suggested Reading
- •Website
- •Suggested Reading
- •25: Aortic Dissection
- •Suggested Reading
- •26: Cerebrovascular Accident
- •Suggested Reading
- •Websites
- •27: Subarachnoid Hemorrhage
- •Suggested Reading
- •Websites
- •28: Status Epilepticus
- •Suggested Reading
- •29: Acute Flaccid Paralysis
- •Suggested Readings
- •30: Coma
- •Suggested Reading
- •Suggested Reading
- •Websites
- •32: Acute Febrile Encephalopathy
- •Suggested Reading
- •33: Sedation and Analgesia
- •Suggested Reading
- •Websites
- •34: Brain Death
- •Suggested Reading
- •Websites
- •35: Upper Gastrointestinal Bleeding
- •Suggested Reading
- •36: Lower Gastrointestinal Bleeding
- •Suggested Reading
- •37: Acute Diarrhea
- •Suggested Reading
- •38: Acute Abdominal Distension
- •Suggested Reading
- •39: Intra-abdominal Hypertension
- •Suggested Reading
- •Website
- •40: Acute Pancreatitis
- •Suggested Reading
- •Website
- •41: Acute Liver Failure
- •Suggested Reading
- •Suggested Reading
- •Websites
- •43: Nutrition Support
- •Suggested Reading
- •44: Acute Renal Failure
- •Suggested Reading
- •Websites
- •45: Renal Replacement Therapy
- •Suggested Reading
- •Website
- •46: Managing a Patient on Dialysis
- •Suggested Reading
- •Websites
- •47: Drug Dosing
- •Suggested Reading
- •Websites
- •48: General Measures of Infection Control
- •Suggested Reading
- •Websites
- •49: Antibiotic Stewardship
- •Suggested Reading
- •Website
- •50: Septic Shock
- •Suggested Reading
- •51: Severe Tropical Infections
- •Suggested Reading
- •Websites
- •52: New-Onset Fever
- •Suggested Reading
- •Websites
- •53: Fungal Infections
- •Suggested Reading
- •Suggested Reading
- •Website
- •55: Hyponatremia
- •Suggested Reading
- •56: Hypernatremia
- •Suggested Reading
- •57: Hypokalemia and Hyperkalemia
- •57.1 Hyperkalemia
- •Suggested Reading
- •Website
- •58: Arterial Blood Gases
- •Suggested Reading
- •Websites
- •59: Diabetic Emergencies
- •59.1 Hyperglycemic Emergencies
- •59.2 Hypoglycemia
- •Suggested Reading
- •60: Glycemic Control in the ICU
- •Suggested Reading
- •61: Transfusion Practices and Complications
- •Suggested Reading
- •Websites
- •Suggested Reading
- •Website
- •63: Onco-emergencies
- •63.1 Hypercalcemia
- •63.2 ECG Changes in Hypercalcemia
- •63.3 Superior Vena Cava Syndrome
- •63.4 Malignant Spinal Cord Compression
- •Suggested Reading
- •64: General Management of Trauma
- •Suggested Reading
- •65: Severe Head and Spinal Cord Injury
- •Suggested Reading
- •Websites
- •66: Torso Trauma
- •Suggested Reading
- •Websites
- •67: Burn Management
- •Suggested Reading
- •68: General Poisoning Management
- •Suggested Reading
- •69: Syndromic Approach to Poisoning
- •Suggested Reading
- •Websites
- •70: Drug Abuse
- •Suggested Reading
- •71: Snakebite
- •Suggested Reading
- •72: Heat Stroke and Hypothermia
- •72.1 Heat Stroke
- •72.2 Hypothermia
- •Suggested Reading
- •73: Jaundice in Pregnancy
- •Suggested Reading
- •Suggested Reading
- •75: Severe Preeclampsia
- •Suggested Reading
- •76: General Issues in Perioperative Care
- •Suggested Reading
- •Web Site
- •77.1 Cardiac Surgery
- •77.2 Thoracic Surgery
- •77.3 Neurosurgery
- •Suggested Reading
- •78: Initial Assessment and Resuscitation
- •Suggested Reading
- •79: Comprehensive ICU Care
- •Suggested Reading
- •Website
- •80: Quality Control
- •Suggested Reading
- •Websites
- •81: Ethical Principles in End-of-Life Care
- •Suggested Reading
- •82: ICU Organization and Training
- •Suggested Reading
- •Website
- •83: Transportation of Critically Ill Patients
- •83.1 Intrahospital Transport
- •83.2 Interhospital Transport
- •Suggested Reading
- •84: Scoring Systems
- •Suggested Reading
- •Websites
- •85: Mechanical Ventilation
- •Suggested Reading
- •86: Acute Severe Asthma
- •Suggested Reading
- •87: Status Epilepticus
- •Suggested Reading
- •88: Severe Sepsis and Septic Shock
- •Suggested Reading
- •89: Acute Intracranial Hypertension
- •Suggested Reading
- •90: Multiorgan Failure
- •90.1 Concurrent Management of Hepatic Dysfunction
- •Suggested Readings
- •91: Central Line Placement
- •Suggested Reading
- •92: Arterial Catheterization
- •Suggested Reading
- •93: Pulmonary Artery Catheterization
- •Suggested Reading
- •Website
- •Suggested Reading
- •95: Temporary Pacemaker Insertion
- •Suggested Reading
- •96: Percutaneous Tracheostomy
- •Suggested Reading
- •97: Thoracentesis
- •Suggested Reading
- •98: Chest Tube Placement
- •Suggested Reading
- •99: Pericardiocentesis
- •Suggested Reading
- •100: Lumbar Puncture
- •Suggested Reading
- •Website
- •101: Intra-aortic Balloon Pump
- •Suggested Reading
- •Appendices
- •Appendix A
- •Appendix B
- •Common ICU Formulae
- •Appendix C
- •Appendix D: Syllabus for ICU Training
- •Index
Hypokalemia and Hyperkalemia |
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Subhash Todi and Rajesh Chawla |
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A 50-year-old male patient was admitted with generalized weakness and abdominal distension. On examination, he was found to be alert and hemodynamically stable. Neurological examination revealed quadriparesis. Abdominal examination revealed distension with sluggish bowel sounds. His serum potassium level was 2 mEq/L.
Disorder of potassium balance—both hypoand hyperkalemia—is a common finding in the ICU. These abnormalities might be subtle requiring minimal intervention or life-threatening requiring urgent measures. A methodological approach is warranted to manage this problem.
Step 1: Initial resuscitation
•Patients should be resuscitated, as mentioned in Chap. 78.
•Patients with quadriparesis need to be assessed for airway protection and if needed should be intubated or ventilated.
•Circulatory status needs to be maintained with intravenous fluids as hypokalemic patients are usually volume depleted.
Step 2: Assess severity of hypokalemia
•After initial resuscitation, the patient should be assessed for urgency of correction of hypokalemia.
S. Todi, M.D., M.R.C.P. (*)
Critical Care & Emergency, A.M.R.I. Hospital, Kolkata, India e-mail: drsubhashtodi@gmail.com
R. Chawla, M.D., F.C.C.M.
Department of Respiratory, Critical Care & Sleep Medicine, Indraprastha Apollo Hospitals, New Delhi, India
e-mail: drchawla@hotmail.com
R. Chawla and S. Todi (eds.), ICU Protocols: A stepwise approach, |
447 |
DOI 10.1007/978-81-322-0535-7_57, © Springer India 2012 |
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S. Todi and R. Chawla |
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Table 57.1 ECG changes in hypokalemia
Fig. 57.1 Hypokalemia
ST segment depression
Decrease in amplitude of T waves
Increase in amplitude of U wave (occurring at the end of T)
Premature atrial or ventricular ectopics
Sinus bradycardia
Paroxysmal atrial or junctional tachycardia
Atrioventricular block
Ventricular tachycardia (torsade de pointes)
Ventricular fibrillation
•Urgent intravenous correction is needed in the following conditions:
–ECG changes in hypokalemia (see Table 57.1 and Fig. 57.1)
–Cardiac arrhythmia
–Severely impaired neuromuscular function
–Diaphragmatic weakness and respiratory failure
–Patients on digoxin or antiarrhythmic therapy
–Old age
–Organic heart disease
–Serum potassium of less than 3.0 mEq/L
–Diabetic ketoacidosis
–Hyperosmolar nonketotic diabetes
Step 3: Estimate potassium deficit
•Approximately 200 mEq potassium deficit is required to decrease serum potassium by 1 mEq/L in the chronic hypokalemic state.
•In acute situations, the serum potassium concentration falls by approximately 0.27 mEq/L for every 100 mEq reduction in total body potassium stores.
•These are only an approximation, and careful monitoring of serum potassium is required.
57 Hypokalemia and Hyperkalemia |
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Step 4: Replace intravenous potassium chloride
Peripheral route
It is safe
It is used in mild-to-moderate hypokalemia (3–3.5 mEq/L)
20–40 mEq/L of KCl is added to each liter of fluid given over 4–6 h
A saline rather than dextrose solution should be used. Half-strength saline with 20 mEq of KCl makes the solution isotonic and suitable for peripheral use
Do not use high concentrations over 60 mEq/l; it can lead to pain and sclerosis of peripheral vein Volume overload is a potential risk in susceptible subjects
Central route
Prepare 20 mEq KCl in 100 mL normal or half-strength saline
5–20 mEq/h (through syringe pump) can be safely given by central route (preferably femoral vein)
Life-threatening arrhythmias
Up to 40 mEq/h of KCl can be given for few hours
No other infusion should be going through the same catheter
Avoid blood sampling and flushing the catheter
Frequently monitor potassium till 3–3.5 mEq/L
Continuous ECG monitoring is required
Step 5: Replace intravenous magnesium
•Hypomagnesemia is usually concurrently present with hypokalemia and needs to be corrected.
Step 6: Ascertain the cause of hypokalemia and manage specifically (Table 57.2)
•Detailed history and physical examination should be performed to look for systemic causes of hypokalemia.
•History of increased urinary or gastrointestinal loss of fluid (vomiting, diarrhea, polyuria) should be taken.
•Detailed drug history to rule out drug-induced hypokalemia should also be taken.
•Urinary potassium level of more than 30 mEq/day is a feature of loss of potassium in the urine.
Step 7: Send investigation
•Complete blood count
•Na, K, Ca, Mg, PO4, HCO3
•Urea, creatinine
•Creatine phosphokinase (CPK)
•Arterial blood gas analysis
•ECG
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S. Todi and R. Chawla |
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Table 57.2 Causes of hypokalemia
Increased entry into cells
Metabolic alkalosis
Initial phase of DKA
Elevated b-adrenergic activity—stress or administration of b-agonists
Hypokalemic periodic paralysis Hypothermia
Chloroquine intoxication
Others
Vomiting
Diarrhea Tube drainage Laxative abuse
Increased urinary losses Diuretics
Primary mineralocorticoid excess Hypomagnesemia
Amphotericin B
Salt-wasting nephropathies—including Bartter’s or Gitelman’s syndrome
Renal Tubular Acidosis, Polyuria
Increased sweat losses
Dialysis
Plasmapheresis
Decreased potassium intake (rare)
•Urine for K
•Urinalysis
Step 8: Replace potassium orally
•Once serum potassium has been raised to a safe limit of above 3 mEq/L, the rest of the replacement may be done slowly by oral route. This could be achieved by adding potassium-rich diet, potassium salt, or potassium chloride suspension.
•Treatment is usually started with 10–20 mEq of potassium chloride given two to four times per day (20–80 mEq/day).
Step 9: Reduce the loss of potassium
•In patients with hypokalemia due to increased urinary losses, potassium-sparing diuretics such as spironolactone, amiloride, or eplerenone may be tried.
•Oral/IV potassium should be used with caution in these situations specially in patients with impaired renal function.