Chapter 59: HYPERKALEMIA

YOUR PATIENT

An 8-year-old child presents with a history of end-stage renal disease (ESRD) from glomerulonephritis. He is not dialysis dependent, and he comes to the operating room for a nonscheduled renal transplant.

• Laboratory findings: K 7.5; HCO₃ 14

• Electrocardiogram (ECG): Peaked T waves in all leads

PREOPERATIVE CONSIDERATIONS

Chronic renal failure in children has a prevalence of about 18-58 cases per million children. The incidence is equal in both sexes, although obstructive uropathies are more common in males.

• Although the potassium may be chronically elevated in chronic kidney disease, this presentation is notable for the cardiac abnormality noted on ECG. Because of this finding, one should be concerned and make an effort to decrease the potassium prior to induction of anesthesia.

• The bicarbonate level is also chronically low in kidney disease due to metabolic acidosis. The patient is probably taking supplemental bicarbonate at home, and this should be given not only to treat the acidosis, but also to help promote intracellular movement of potassium and treat the hyperkalemia.

ANESTHETIC MANAGEMENT

• Hyperkalemia is treated with insulin, dextrose, and sodium bicarbonate prior to arrival at the operating room.

• Administer dextrose 1 g/kg IV over 15 minutes with 0.2 unit insulin/kg.

• Administer calcium chloride 4-5 mg/kg IV over 5-10 minutes to stabilize cardiac membrane.

• Administer 1 mEq/kg of sodium bicarbonate over 10 minutes.

• Kayexalate administered rectally has faster activity than oral. Administer Kayexalate 1 g/kg rectally every 2 hours as needed.

• Consider furosemide administration and/or albuterol treatment.

• Repeat potassium and ECG after therapy to monitor for resolution.

• General anesthesia may reduce renal blood flow in up to 50% of patients, so remain cautious in patients with renal insufficiency.

• The function of cholinesterase may be impaired, resulting in a prolonged effect of succinylcholine if it is used in patients with ESRD. Caution with succinylcholine use is particularly indicated where potassium is elevated, as succinylcholine transiently exacerbates hyperkalemia.

• Consider normal saline usage for IV hydration given decreased potassium content.

• Use fentanyl and hydromorphone for opioids. Avoid morphine, as its metabolites remain detectable in renal failure patients long after they are metabolized in patients without kidney disease.

POSTOPERATIVE CONSIDERATIONS

Small infants who receive adult organs may have respiratory compromise after transplant and may require posttransplant ventilation for hours or days due to increased intra-abdominal pressure.

CONTROVERSIES

• Large volumes of normal saline can cause a metabolic acidosis.

• Vasoconstrictors can decrease renal perfusion.

SURGICAL CONCERNS

When vascular clamps are released, you may note hemodynamic changes. Hypotension is common and usually ...