Transcript Hyperkalemia

UC-Irvine Internal Medicine
Mini-Lecture Series
C L I N I C A L D I AG N O S I S A N D A P P ROAC H
TO
HYPERKALEMIA
Objectives
 1.
 2.
 3.
Understand diagnosis of hyperkalemia based on clinical
data
Understand ECG changes present in hyperkalemic states
Understand treatment/therapy approaches available for
hyperkalemia
Clinical Scenario
 A 52-year-old man with hypertension and diabetes complains of weakness,
nausea, and a general sense of illness, that has progressed slowly over 3 days.
His medications include a sulonylurea, a diuretic, and an ACE inhibitor. On
examination, he appears lethargic and ill. His BP is 154/105 mm Hg, HR
70bpm, temperature 98.6° F, and respiratory rate 22 breaths/min. The
physical examination reveals moderate jugular venous distension, some
minor bibasilar rales, and lower extremity edema. He is oriented to person
and place but is able to give further history. The ECG shows a wide complex
rhythm.
 Laboratory studies performed are significant for potassium 7.8 mEq/L, BUN is
114 mg/dL and creatinine is 10.5.
Diagnostics/Images: ECG
ECG Changes of Hyperkalemia
 Easily Distinguished ECG signs:
peaked T wave.
 prolongation of the PR interval
 ST changes (which may mimic myocardial infarction)
 very wide QRS, which may progress to a sine wave pattern and
asystole.

 Patients may have severe hyperkalemia with minimal ECG
changes, and prominent ECG changes with mild hyperkalemia.
Analysis
 Diagnosis: Hyperkalemia- Severe

Classification of Hyperkalemia
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NORMAL: 3.5 to 5.0 mEq/L.
MILD: 5.5 to 6.0 mEq/L
SEVERE: Levels of 7.0 mEq/L or greater
 It is important to suspect this condition from the history and
ECG, because laboratory test results may be delayed and the
patient could die before those test results become available.
Therapy Approach
 BIG K Drop
B - beta agonists, bicarbonate
 I - Insulin
 G - Glucose
 K - Kayexulate, Calcium
 D - Diuretics, Dialysis

1st Line option
Reference: Hollander JC, Calvert CJ. Hyperkalemia. Am Fam Physician 2006; 73:283-90,
Figure 2.
Clinical Pearls
 Symptoms of hyperkalemia are usually nonspecific, so risk
factors must be used to suspect the diagnosis
 ECG changes consistent with hyperkalemia should be treated
immediately as a life-threatening emergency. Do not await
laboratory confirmation.
 Intravenous calcium is the antidote of choice for life-threatening
arrhythmias related to hyperkalemia, but its effect is brief and
additional agents must be used
Comprehension Questions
QUESTION 1:
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A 55-year-old man presents in cardiac arrest. A dialysis fistula is present in the right arm. In
addition to standard ACLS therapies, which of the following is most appropriate for this
patient?
A. 25 g of 50% dextrose, IV push.
B. Sodium bicarbonate, 50-mL IV push.
C. Begin immediate hemodialysis.
D. Calcium gluconate, slow intravenous push.
QUESTION 2:
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A 45-year-old man is brought into the emergency center due to significant dehydration and
weakness. His potassium level is noted to be 7 mEq/L. Which of the following statements is
most accurate regarding his potassium level?
A. Hyperkalemia can usually be diagnosed by symptoms alone.
B. An ECG showing peaked T waves means the patient is stable and treatment can safely wait
until laboratory results are obtained.
C. Hyperkalemia can mimic a myocardial infarction on the ECG.
D. Hyperkalemia is synonymous with kidney disease.
Comprehension Questions
QUESTION 3:
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Which of the following statements regarding treatment of hyperkalemia in patients with some
renal function is incorrect?
A. Administration of normal saline may hasten the excretion of potassium.
B. Administration of furosemide can hasten the excretion of potassium.
C. The combination of saline with a diuretic is often indicated because hyperkalemic patients
are frequently dehydrated.
D. Patients with some renal function do not need dialysis even for severe hyperkalemia.
QUESTION 4:
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A patient with severe renal disease is found to have hyperkalemia, with tall, peaked T waves on
ECG. Vascular access cannot be readily obtained, but vital signs are stable. Which of the
following would be appropriate temporizing measures?
A. Inhaled albuterol 2.5 mg in 3 mL saline
B. Oral sodium bicarbonate with rectal sodium polystyrene sulfonate
C. Inhaled albuterol 20 mg, with oral or rectal sodium polystyrene sulfonate, 30 g
D. Oral dextrose 25 g
References
 Evans KJ, Greenberg A. Hyperkalemia: a review. J Intensive Care
Med. 2005 Sep-Oct;20(5):272-290.
 Kamel KS, Wei C. Controversial issues in the treatment of
hyperkalaemia. Nephrol Dial Transplant. 2003;18:2215-2218.
 Sood MM, Sood AR, Richardson R. Emergency management and
commonly encountered outpatient scenarios in patients with
hyperkalemia. Mayo Clin Proc. 2007 Dec; 82(12):1553-1561.
 Hollander JC, Calvert CJ. Hyperkalemia. Am Fam Physician 2006;
73:283-90