Percutaneous renal biopsies in young children require a high level of immobility to be successfully completed. Although a number of sedative regimens have been proposed, none are completely satisfactory in the pediatric patient. Ketamine is a unique sedative drug with amnestic, analgesic and dissociative sedative properties. The purpose of this study was to evaluate the safety and effectiveness of relatively low dose intravenous ketamine for pediatric renal biopsies.

All children scheduled for a renal biopsy were eligible for the study. Biopsies were performed with an 18 gauge spring loaded biopsy“gun” (Biopty®) under ultrasound guidance. Intravenous midazolam 0.1 mg/kg (max 5 mg) and atropine 0.01 mg/kg (max 0.5 mg) were administered prior to ultrasound localization. Ketamine 0.5 mg/kg was administered every 2 to 3 minutes until there was minimal to no verbal or motor response upon initiation of the procedure. Children were monitored continuously by a pulse oximeter, an electrocardiographic and respiratory monitor and every 3 minute blood pressure measurements. Follow up was conducted by phone 2 to 4 weeks after discharge.

Twenty renal biopsies were performed on children ranging in age from 1.8 to 14.8 years, average age 5.6±0.75 (mean ± SEM). Eleven patients had nephrotic syndrome and nine had glomerulonephritis. Adequate specimens were obtained in all patients, 14 following a single needle pass, 6 following two or three passes. Average ketamine doses were 1.03 ± 0.1 mg/kg(range 0.5 to 2 mg/kg). Signs of discomfort were minimal during the procedure. No oxygen desaturations occurred however heart rate and blood pressure increased 7.3±2.0% and 9.1±1.7% respectively, following ketamine. Gross hematuria developed in one patient, but resolved spontaneously without requiring a blood transfusion. There were no reported sleep or behavioral disturbances on follow up. All children over age 4.5 years (n=11) were amnesic for the procedure.

Intravenous ketamine in doses of 0.5 mg/kg provides safe and effective sedation for successful pediatric percutaneous renal biopsies. Increases in heart rate and blood pressure following ketamine can be expected.