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| {{Infobox_Disease | | | __NOTOC__ |
| Name = Hyperkalemia |
| | {| class="infobox" style="float:right;" |
| Image = K-TableImage.png |
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| Caption = [[potassium]] |
| | | [[File:Siren.gif|30px|link=Hyperkalemia resident survival guide]]|| <br> || <br> |
| DiseasesDB = 6242 |
| | | [[Hyperkalemia resident survival guide|'''Resident'''<br>'''Survival'''<br>'''Guide''']] |
| ICD10 = {{ICD10|E|87|5|e|70}} |
| | |} |
| ICD9 = {{ICD9|276.7}} |
| | {| class="infobox" style="float:right;" |
| ICDO = |
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| OMIM = |
| | | [[File:Critical_pathways_.gif|88px|link=Hyperkalemia critical pathways]]|| <br> || <br> |
| MedlinePlus = |
| | |} |
| MeshID = D006947 |
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| }} | | {{Patient}} |
| {{Hyperkalemia}} | | {{Hyperkalemia}} |
| {{CMG}}; '''Associate Editor(s)-In-Chief:''' [[Priyamvada Singh|Priyamvada Singh, M.B.B.S.]] [mailto:psingh@perfuse.org] | | {{CMG}}; {{AE}} [[Priyamvada Singh|Priyamvada Singh, M.B.B.S.]] [mailto:psingh13579@gmail.com]; [[Jogeet Singh Sekhon]] |
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| | ==[[Hyperkalemia overview|Overview]]== |
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| == [[Hyperkalemia overview | Overview]]== | | ==[[Hyperkalemia historical perspective|Historical Perspective]]== |
| ==[[ Hyperkalemia pathophysiology | Pathophysiology ]]==
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| ==[[ Hyperkalemia causes | Causes ]]==
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| ==[[Hyperkalemia differential diagnosis | Differential diagnosis]]==
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| ==[[Hyperkalemia history and symptoms | History and Symptoms ]]==
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| ==Diagnosis== | | ==[[Hyperkalemia classification|Classification]]== |
| In order to gather enough information for diagnosis, the measurement of potassium needs to be repeated, as the elevation can be due to [[hemolysis]] in the first sample. Generally, blood tests for [[renal function]] ([[creatinine]], [[blood urea nitrogen]]), [[glucose]] and occasionally [[creatine kinase]] and [[cortisol]] will be performed. Calculating the [[trans-tubular potassium gradient]] can sometimes help in distinguishing the cause of the hyperkalemia.
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| In many cases, [[medical ultrasonography|renal ultrasound]] will be performed, since hyperkalemia is highly suggestive of renal failure.
| | ==[[Hyperkalemia pathophysiology|Pathophysiology]]== |
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| Also, [[electrocardiography]] (EKG/ECG) may be performed to determine if there is a significant risk of cardiac [[arrhythmias]] (see [[#ECG/EKG Findings|ECG/EKG Findings]], below).
| | ==[[Hyperkalemia causes|Causes]]== |
| === Laboratory Evaluation ===
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| ====Initial====
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| * Calcium
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| * Phosphate
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| * Magnesium
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| * Blood urea nitrogen (BUN)/creatinine
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| ====Extensive Evaluation====
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| * Cortisol
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| * Renin
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| * Aldosterone levels
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| * Transtubular potassium gradient (by assessing potassium+ secretion)
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| ===Electrocardiographic Findings=== | | ==[[Hyperkalemia differential diagnosis|Differentiating Hyperkalemia from other Diseases]]== |
| [[Electrocardiography]] (ECG) is generally done early to identify any influences on the heart, as hyperkalemia may cause fatal [[arrhythmias]]. With moderate hyperkalemia, there is reduction of the size of the P wave and development of tent-shaped T waves. Further hyperkalemia will lead to widening of the [[QRS complex]], that ultimately may become [[sinusoidal]] in shape. There appears to be a direct effect of elevated potassium on some of the potassium channels that increases their activity and speeds membrane repolarization. Also, (as noted [[#Pathophysiology|above]]), hyperkalemia causes an overall membrane depolarization that inactivates many sodium channels. The faster repolarization of the cardiac [[action potential]] causes the tenting of the T waves, and the inactivation of sodium channels causes a sluggish conduction of the electrical wave around the heart, which leads to smaller P waves and widening of the QRS complex.
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| Spcific findings include the following:
| | ==[[Hyperkalemia epidemiology and demographics|Epidemiology and Demographics]]== |
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| ====Tall, narrow, and peaked [[T waves]]==== | | ==[[Hyperkalemia risk factors|Risk Factors]]== |
| * Earliest sign of hyperkalemia
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| * Occurs with K > 5.5 meq/li
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| * Differential diagnosis of this EKG change includes the T wave changes of [[bradycardia]] or [[stroke]]. Prominent [[U wave]]s and [[QTc]] prolongation are more consistent with [[stroke]] than hyperkalemia.
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| ====Intraventricular conduction defect==== | | ==[[Hyperkalemia screening|Screening]]== |
| #* Observed when K > 6.5 meq/li
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| #* There is a modest correlation of the [[QRS]] duration with serum K
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| #* As the K rises, the [[QRS]] complexes may resemble sine waves
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| #* Generally the widening is diffuse and usually there is no resemblance of the morphology to that of either [[LBBB]] or [[RBBB]]
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| ====Decrease of the amplitude of the P wave or an absent P wave====
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| * Decreased [[P wave]] amplitude occurs when the K is > 7.0 meq/li
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| * [[P wave]]s may be absent when the K is > 8.8 meq/li
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| * The impulses are still being generated in the [[SA node]] and are conducted to the ventricles through specialized atrial fibers without depolarizing the atrial muscle
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| * Moderate or sever hyperkalemia can cause [[sinus arrest]] <ref name="pmid16792034">{{cite journal |author=Bonvini RF, Hendiri T, Anwar A |title=Sinus arrest and moderate hyperkalemia |journal=[[Annales De Cardiologie Et D'angéiologie]] |volume=55 |issue=3 |pages=161–3 |year=2006 |month=June |pmid=16792034 |doi= |url= |issn=}}</ref>
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| ====ST segment changes simulating current of injury==== | | ==[[Hyperkalemia natural history, complications, and prognosis|Natural history, Complications and Prognosis]]== |
| * Have been labeled the dialyzable current of injury
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| ====Cardiac arrhythmias: bradyarrhythmias, tachyarrhythmias, atrioventricular conduction defects====
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| * Occurs with severe hyperkalemia, not mild to moderate hyperkalemia
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| <gallery>
| | ==Diagnosis== |
| Image:Hyperkalemia.jpg|Tall, symmetric, narrow based T waves in a hyperkalemic patient.
| | [[Hyperkalemia diagnostic study of choice|Diagnostic study of choice]] | [[Hyperkalemia history and symptoms|History and Symptoms]] | [[Hyperkalemia physical examination|Physical Examination]] | [[Hyperkalemia laboratory findings|Laboratory Findings]] | [[Hyperkalemia electrocardiogram|Electrocardiogram]] | [[Hyperkalemia x ray|X-Ray Findings]] | [[Hyperkalemia echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Hyperkalemia CT scan|CT-Scan Findings]] | [[Hyperkalemia MRI|MRI Findings]] | [[Hyperkalemia other imaging findings|Other Imaging Findings]] | [[Hyperkalemia other diagnostic studies|Other Diagnostic Studies]] |
| Image:Ecg hyperkaliemie.jpg|A patient's EKG with hyperkalemia.
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| Image:Ecg hyperkaliemie2.jpg|Same patient's EKG during treatment.
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| </gallery>
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| ==Treatment== | | ==Treatment== |
| When arrhythmias occur, or when potassium levels exceed 6.5 mmol/l, emergency lowering of potassium levels is mandated. Several agents are used to lower K levels. Choice depends on the degree and cause of the hyperkalemia, and other aspects of the patient's condition.
| | [[Hyperkalemia medical therapy|Medical Therapy]] | [[Hyperkalemia surgery|Surgery]] | [[Hyperkalemia primary prevention|Primary Prevention]] | [[Hyperkalemia secondary prevention|Secondary Prevention]] | [[Hyperkalemia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Hyperkalemia future or investigational therapies|Future or Investigational Therapies]] |
| * [[Calcium]] supplementation (calcium gluconate 10% (10ml), preferably through a [[central venous catheter]] as the calcium may cause [[phlebitis]]) does not lower potassium but decreases [[myocardium|myocardial]] excitability, protecting against life threatening [[arrhythmias]].
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| * [[Insulin]] (e.g. intravenous injection of 10-15u of (short acting) insulin (e.g. Actrapid) {along with 50ml of 50% dextrose to prevent hypoglycemia}) will lead to a shift of potassium ions into cells, secondary to increased activity of the [[sodium-potassium ATPase]].
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| * [[Bicarbonate]] therapy (e.g. 1 ampule (45mEq) infused over 5 minutes) is effective in cases of metabolic acidosis. The bicarbonate ion will stimulate an exchange of cellular H<sup>+</sup> for Na<sup>+</sup>, thus leading to stimulation of the [[sodium-potassium ATPase]].
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| * [[Salbutamol]] (albuterol, Ventolin<sup>®</sup>) is a β<sub>2</sub>-selective catacholamine that is administered by nebuliser (e.g. 10-20 mg). This drug promotes movement of K into cells, lowering the blood levels.
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| * [[Polystyrene sulfonate]] (Calcium Resonium, Kayexalate) is a binding resin that binds K within the intestine and removes it from the body by defecation. Calcium Resonium (15g three times a day in water) can be given by mouth. Kayexelate can be given by mouth or as an [[enema]]. In both cases, the resin absorbs K within the intestine and carries it out of the body by [[defecation]]. This medication may cause diarrhea.
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| * Refractory or severe cases may need [[dialysis]] to remove the potassium from the circulation.
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| * Preventing recurrence of hyperkalemia typically involves reduction of dietary potassium, removal of an offending medication, and/or the addition of a [[diuretic]] (such as [[furosemide]] (Lasix<sup>®</sup>) or [[hydrochlorothiazide]]).
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| ==See also== | | ==Case Studies== |
| * [[Hypokalemia]]
| | [[Hyperkalemia case study one|Case #1]] |
| * [[Renal failure]]
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| ==References==
| | [[Category:Emergency medicine]] |
| <references />
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| {{Endocrine, nutritional and metabolic pathology}}
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| {{Electrocardiography}}
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| [[Category:Potassium]] | |
| [[Category:Medical emergencies]]
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| [[Category:Endocrinology]]
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| [[Category:Nephrology]] | | [[Category:Nephrology]] |
| [[Category:Electrolyte disturbance]] | | [[Category:Laboratory tests]] |
| [[Category:Blood tests]]
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| [[Category:Emergency medicine]]
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| [[Category:Intensive care medicine]]
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| [[de:Hyperkaliämie]]
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| [[et:Hüperkaleemia]]
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| [[es:Hipercalemia]]
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| [[fr:Hyperkaliémie]]
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| [[ja:高カリウム血症]]
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| [[pl:Hiperkaliemia]]
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| [[pt:Hipercaliémia]]
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| [[vi:Tăng kali máu]]
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