Optimal Dosing of Ketamine for Procedural Sedation and Analgesia in Children

This was a prospective, double-blind, randomized controlled trial of children aged 3 to 18 years who received IV ketamine for procedural sedation and analgesia (PSA) for orthopedic procedures, incision and drainage (I \& D) of skin abscess and laceration repair in an inner city, tertiary care pediatric ED. Random sequence allocation was performed using a computer-generated, random number table by the study research pharmacist. The study participants were grouped according to their age as follows (1) 3-6 years (2) 7-12 years (3) 13-18 years. Children from each age group were assigned in equal numbers to all three ketamine dosing (1 mg/kg, 1.5 mg/kg and 2 mg/kg) groups using random permuted blocks stratified by the pharmacist. All ED staff including the physician and the nurse in charge of sedation, the study research assistant, the parents/guardians and the study subjects were blinded to the randomization and the group assignments. The dosage and administration of additional doses of ketamine were left to the discretion of the ED physician in charge of the sedation. The research team did not participate in the clinical care including sedation of the patient. Children were monitored per ED policy for the entire duration of sedation. Three 1 ml blood samples for the ketamine assay was collected from the existing intravenous access at three time intervals: 3-5 minutes after ketamine administration, at midpoint during the procedure and prior to discharge of the patient from the ED. In the event a second dose of ketamine was administered, a 4th 1 ml sample was collected 3-5 minutes after the 2nd dose in children weighing \>20 kilograms. Patient demographics, procedure type, NPO status , ASA classification, pain medication administered prior to sedation (timing, dosage and type), number and total doses of ketamine administered after the initial study dose, sedation efficacy and duration, length of procedure, adverse events related to sedation, interventions performed to address the adverse events and patient disposition were collected. The study research assistant also performed a follow up phone call to the parents/caregivers of the children 48 hours after ED discharge to collect information on adverse events that happened at home . A total of 3 attempts were made to contact the parent/caregiver after which the participant was considered as lost to followup.