Clinical Diagnosis and approach to

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UC-Irvine Internal MedicineMini-Lecture Series

• Clinical Diagnosis and approach to
• HYPERKALEMIA

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Objectives

• 1. Understand diagnosis of hyperkalemia based on
  clinical data
• 2. Understand ECG changes present in
  hyperkalemic states
• 3. Understand treatment/therapy approaches
  available for hyperkalemia

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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.

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Diagnostics/Images ECG
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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.

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Analysis

• Diagnosis Hyperkalemia- Severe
• Classification of Hyperkalemia
• 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.

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Therapy Approach

• BIG K Drop
• B - beta agonists, bicarbonate
• I - Insulin
• G - Glucose
• K - Kayexulate, Calcium
• D - Diuretics, Dialysis

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1st Line option
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Reference Hollander JC, Calvert CJ.
Hyperkalemia. Am Fam Physician 2006 73283-90,
Figure 2.
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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

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Comprehension Questions

• QUESTION 1 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 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.

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Comprehension Questions

• QUESTION 3 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 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

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References

• Evans KJ, Greenberg A. Hyperkalemia a review. J
  Intensive Care Med. 2005 Sep-Oct20(5)272-290.
• Kamel KS, Wei C. Controversial issues in the
  treatment of hyperkalaemia. Nephrol Dial
  Transplant. 2003182215-2218.
• 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 73283-90