Hyperkalemia: Difference between revisions

Revision as of 23:40, 1 March 2011

Background

High = >5.5meq/L

High! = >6.5meq/L

Diagnosis

Always consider pseudohyperkalemia (e.g. from hemolysis)

ECG

6.5 - peaked Ts, inc PR, dec QT

7.5 - QRS widening, P flattening

8 - sine wave, v-fib, heart block

Differential Diagnosis

A. Redistribution

    1. Acidosis drives potassium out of the cells

      a.  DKA

    2. Cellular breakdown

      a. Rhabdomyolysis

      b. Hemolysis

      c. Tumor lysis syndrome

      d.  Crush

B. Increased total body potassium

    1. Inadequate excretion

      a. Renal caused (acute or chronic renal failure-must have GFR<10)

      b. Mineralocorticoid deficiency or Addison's disease

      c. Drug-induced (potassium sparing diuretics [e.g., spironolactone] and ACE-inhibitors)

    2. Excessive intake

      a. Diet, meds

      b. Blood transfusion

C. Pseudohyperkalemia

    1. Hemolysis of the specimen

    2. Prolonged period of tourniquets occlusion prior to blood draw

    3. Thrombocytosis/leukocytosis

D. Misc

    1.  Succs, dib, B-blockers

Treatment

Calcium gluconate 1 amp IV (if ECG changes/hypotension/or >7; can give mult times)
Caution in dig-toxic patients!
Albuterol neb 2.5mg x 3
10 U reg insulin IV with 1 amp D50W IV now, and 1 amp in 15 min
1 amp NaBicarb IV (over 5 min)
Kayexalate 30g PO (may cause volume overload; +/- 50mL sorbitol)
Consider dialyisis & ?lasix

Source

7/2/09 Adapted from Tintinalli, Donaldson, Pani

@@ Line 1: / Line 1: @@
 ==Background==
 High = >5.5meq/L
 High! = >6.5meq/L
 ==Diagnosis==
 Always consider pseudohyperkalemia (e.g. from hemolysis)
+=== ===
 ===ECG===
 .5 - peaked Ts, inc PR, dec QT
@@ Line 15: / Line 24: @@
 - sine wave, v-fib, heart block
 ==Differential Diagnosis==
-'''A. Increased potassium release from cells
-'''
-* 1. Pseudohyperkalemia
-** a. Hemolysis of specimen
-** b. Leukocytosis and thrombocytosis
-*** 1. K+ increases by 0.15 meq for every 100,000 elevation in plt count
-* 2. Metabolic Acidosis
-** a. Drives potassium out of cells
-* 3. Insulin deficiency
-* 4. Hyperosmolality
-* 5. Cellular breakdown
-** a. Rhabdomyolysis
-** b. Hemolysis
-** c. Tumor lysis syndrome
-** d. Crush
-'''B. Reduced urinary potassium excretion
+A. Redistribution
-'''
-* 1. Renal failure - must have GFR <10
+. Acidosis drives potassium out of the cells
-* 2. Aldosterone deficiency
-** a. Addison's disease
+       a.  DKA
-** b. ACEI
-* 3. Aldosterone resistance
+. Cellular breakdown
-** a. Diuretics - Amiloride, spironolactone, triamterene
-* 4. Hypoperfusion
+       a. Rhabdomyolysis
-* 5. Excessive intake
-** a. Diet, meds
+       b. Hemolysis
-** b. Blood transfusion
+       c. Tumor lysis syndrome
+       d.  Crush
+B. Increased total body potassium
+. Inadequate excretion
+       a. Renal caused (acute or chronic renal failure-must have GFR<10)
+       b. Mineralocorticoid deficiency or Addison's disease
+       c. Drug-induced (potassium sparing diuretics [e.g., spironolactone] and ACE-inhibitors)
+. Excessive intake
+       a. Diet, meds
+       b. Blood transfusion
+C. Pseudohyperkalemia
+. Hemolysis of the specimen
+. Prolonged period of tourniquets occlusion prior to blood draw
+. Thrombocytosis/leukocytosis
+D. Misc
+.  Succs, dib, B-blockers
-'''C. Misc
-'''
-* 1. Sux, digoxin overdose, B-blockers (only significant cause if pt also has renal failure)
 ==Treatment==
-* 1. Calcium Gluconate 1 amp IV
-** a. Give only if ECG changes/hypotension/or >7
-** b. Can give multiple times
-** c. Can also give CaCl 1 amp (but can lead to calcium toxicity)
-** d. Caution in dig-toxic patients!
-** e. Effect begins within minutes, lasts 30-60 minutes
-* 2. Albuterol neb 10mg in 4mL saline over 10 min
-** a. Peak effect within 90 min
-** b. Lowers K ~ 0.5-1.5
-* 3. Reg insulin 10 U IV with 1 amp D50W IV now, and 1 amp in 15 min
-** a. Effect begins in 10-20 min, peaks at 30-60 min, lasts 4-6 hours
-** b. Lowers K ~ 0.5 - 1.2
-* 4. Bicarbonate
-** a. Controversial
-** b. NaBicarb 1 amp IV (over 5 min)
-* 5. Kayexalate 30g PO or 50g PR (may cause hypernatremia and volume overload)
-* 6. Dialyisis
+* Calcium gluconate 1 amp IV (if ECG changes/hypotension/or >7; can give mult times)
+* Caution in dig-toxic patients!
+* Albuterol neb 2.5mg x 3
+* 10 U reg insulin IV with 1 amp D50W IV now, and 1 amp in 15 min
+* 1 amp NaBicarb IV (over 5 min)
+* Kayexalate 30g PO (may cause volume overload; +/- 50mL sorbitol)
+* Consider dialyisis & ?lasix