Hyperkalaemic cardiac arrest following intravenous hydralazine and propranolol therapy post-embolectomy

Prolonged asystolic hyperkalemic cardiac arrest with no neurologic sequelae

We report the case of a 70-year-old man who developed cardiac arrest secondary to hyperkalemia that complicated severe chronic renal failure due to obstructive uropathy. The patient experienced electromechanical dissociation and approximately 26 minutes of asystole after which the resuscitation was suspended. However, 8 to 10 minutes after declaration of death, the patient was noted to have developed spontaneous return of circulation as the emergency department personnel were preparing to transport him to the morgue. The patient survived and was discharged without apparent neurologic sequelae. This case demonstrates the challenges facing physicians to predict the outcome of hyperkalemic cardiac arrest based on usual parameters. It also highlights the relative paucity of resuscitation guidelines to assist in the management of this medical emergency.

Disorders of potassium homeostasis

Hypokalemia and hyperkalemia are common problems that may be artifactual, iatrogenic, or due to altered body homeostatic mechanisms. ECG may help one to recognize hyperkalemia but not hypokalemia. Excessive K supplementation is a common iatrogenic cause of hyperkalemia whereas fluid therapy is a common cause of iatrogenic hypokalemia. The most common causes of spontaneous hyperkalemia are renal failure and hypoadrenocorticism whereas the most common causes of spontaneous hypokalemia are vomiting, diarrhea, and renal wasting. Symptomatic therapy is usually done until the underlying cause(s) is resolved.

Serum potassium concentrations following succinylcholine in patients undergoing beta-adrenoceptor blocking therapy

Efflux of serum potassium following succinylcholine was compared in surgical patients undergoing low-dose, long-term beta 1-adrenoceptor or beta 1,2-adrenoceptor blocking therapy and in those receiving neither of these therapies. There were no significant differences in serum potassium concentration prior to, and over a study period of, 2 hours following succinylcholine administration among the three groups of patients.

Hypokalaemia and respiratory acidosis following partial obstruction of the airway

An 87-year-old female, with a history of hypertension controlled with hydrochlorothiazide, was scheduled for excision of a cystic mass of the left lobe of the thyroid. In the course of the anaesthetic, she developed partial airway obstruction that resulted in respiratory acidosis (PaCO2 108 mmHg, pH 7.06), developed premature ventricular contractions and experienced a reduction in plasma potassium concentration from 3.9 to 2.9 mmole X L-1. We interpret this hypokalaemia as a consequence of the epinephrine discharge due to hypercapnia. The case is reported to emphasize the importance of minimizing the sympathetic response to induction of anaesthesia, intubation and surgery in patients with marginal potassium stores.