Infant Hyperkalemic Arrest After Succinylcholine

Abstract

To the Editor: There has been much controversy recently regarding the use of succinylcholine in children [1,2]. We wish to describe a recent case of a child who sustained a hyperkalemic arrest after administration of succinylcholine. An 8-month-old, 7.3-kg male was scheduled for myringotomy tube removal and possible adenoidectomy. He had previously undergone general anesthesia for placement of the myringotomy tubes without problems. Usual monitoring was used. Atropine 0.1 mg and thiopental 35 mg were given intravenously (IV) for induction of anesthesia. General anesthesia via a mask was maintained with N2 O, O2, and halothane. The first tube was removed uneventfully from the right ear. The surgeons then performed a digital examination and decided to perform an adenoidectomy. Airway obstruction at this time necessitated rapid securing of the airway. After succinylcholine 14 mg IV, a marked increase in masseter muscle tone was noted while attempting to open the mouth for endotracheal intubation. An endotracheal tube was inserted. Concurrently, the electrocardiogram (ECG) monitor revealed a wide complex tachycardia progressing to bradycardia Figure 1. The capnograph showed ETCO2 with values of 40-50 mm Hg, which gradually decreased to 25 mm Hg. Arterial saturations decreased from 100% immediately after intubation to 80%. Eventually the pulse oximeter could not detect adequate pulsation to determine a value. Halothane and N2 O were discontinued immediately, and hyperventilation with 100% O2 was initiated. Calcium chloride, epinephrine, and sodium bicarbonate were given IV. The ECG became increasingly dysmorphic and pulses became nonpalpable. Chest compressions were begun. Five minutes later, analysis of a venous blood gas revealed pH 7.13 PCO2 73 mm Hg, PO2 29 mm Hg, and potassium of more than 10 mmol/L. Repeat doses of calcium, epinephrine, and sodium bicarbonate were given. After 13 min of resuscitation, the patient exhibited return of a narrow complex tachycardia with improved perfusion. Systolic blood pressures were 80-100 mm Hg, and the heart rate was 200 bpm. Twenty minutes after succinylcholine administration, a venous blood gas analysis showed pH 7.30, PCO2 49 mm Hg, PO (2) 39 mm Hg, and potassium of 7.1 mmol/L.Figure 1: Electrocardiogram showing a wide complex tachycardia progressing to bradycardia.A urinary catheter was placed, revealing red urine. The patient was transported to the pediatric intensive care unit. A creatine kinase level 8 h postoperatively was 285,760 U/L (normal 61-200 U/L). The patient was treated with vigorous IV hydration. His trachea was extubated shortly after arrival to the intensive care unit and remained hemodynamically stable. He was discharged to home in good condition with no apparent sequelae. DNA studies performed prior to discharge showed a deletion of the dystrophin gene consistent with a diagnosis of Duchenne muscular dystrophy. Reports from the Malignant Hyperthermia Association of the United States indicate that, in the last 2 yr, at least six deaths have occurred on induction of anesthesia in young boys given halothane and succinylcholine; many were suspected or confirmed to have muscular dystrophy at autopsy [3]. Because of these and other reports, routine use of succinylcholine in children is contraindicated "except when used for emergency tracheal intubation or instances where immediate securing of the airway is necessary" [4]. We were in accordance with the current specific indications. Rather than attempting to limit our ability to use succinylcholine, efforts should be made to educate the practitioner to suspect and treat hyperkalemia appropriately when unexplained cardiac arrest occurs. Sometimes the diagnosis of malignant hyperthermia is suspected, and treatment proceeds with the anticipation that dantrolene therapy will reverse the events. Calcium and sodium bicarbonate will give the most immediate response in treating hyperkalemia. Support of the circulatory system is equally important, with both external cardiac compressions and epinephrine necessary to maintain vascular tone and cardiac output. Insulin and glucose therapy will take longer to have an effect on potassium levels. We present this case to highlight the issue that restricting succinylcholine use will not necessarily prevent these rare complications. Any practitioner who uses succinylcholine should be aware of the potential for adverse effects, recognize them immediately, and be prepared to treat them appropriately. Steven F. Parker, MD Ann Bailey, MD Amelia F. Drake, MD Departments of Anesthesiology and Otolaryngology, School of Medicine, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599-7010