Ketamine

Abstract

Ketamine is used extensively in the developing world (DW) because of its effectiveness, availability, relatively low cost, and presumed safety. This report is a prospective, objective assessment of the efficacy and safety of ketamine when used as the sole anesthetic agent in a general medical practice hospital in the DW in children less than 16 years of age undergoing nonemergent operative procedures. Children undergoing laparotomy, thoracotomy, or craniotomy were excluded. Data analysis included serial arterial hemoglobin saturation (SpO₂) and pulse rate, amount of ketamine utilized, adequacy of anesthesia, and perioperative complications. One hundred thirty-one children undergoing a total of 210 anesthetics were studied. The level of anesthesia was adequate in all cases. The SpO₂ dropped below 90% in 40 (19%) children, below 85% in 25 (12%), and below 80% in 13 (6%). SpO₂ drops occurred significantly (P = 0.004) more often after IM than after IV injection. All drops in SpO₂ were abrupt without premonitory signs. Thirty-three (82.5%) of these 40 children responded readily to airway manipulation with a jaw thrust, and only 7 (3.3% of the total series) required face-mask O₂. None required intubation or positive-pressure ventilation. Transient laryngospasm occurred in 1 child, but there were no other complications. In particular, there was no mortality, apnea, emesis, excessive salivation, or significant early or delayed emergence phenomena. Ketamine is quite effective when used as the sole anesthetic agent in DW children. It is relatively safe, but hypoxemia may go undetected unless technologically sophisticated monitoring equipment is available. Proper suction and ventilatory support equipment should be readily available prior to ketamine injection. The first step when hypoxemia is detected is simple airway manipulation, followed by oxygen administration by face mask if needed. Rarely will intubation be indicated. Ketamine is also a good drug for the management of pediatric emergency department procedures in the United States, but all children in these more developed centers should be monitored with a pulse oximeter, since a significant number of children have a precipitous drop in SpO₂.