Effects of a propofol--ketamine admixture in human volunteers.

As the ideal sedative does not exist for all situations, particularly in settings with limited resources, the effect of a propofol-ketamine combination in human volunteers was examined. Eleven American Society of Anesthesiologists (ASA) physical status I volunteers were administered propofol at a loading dose of 1 mg/kg and two minutes later by 0.7 mg/kg of ketamine. This was followed by a propofol-ketamine combination of 5 mg/kg of propofol admixed with 0.7 mg/kg of ketamine that was infused over one hour via a 60 gtts/ml intravenous. Infusion set. Cardiorespiratory parameters were recorded and blood samples taken to measure plasma catecholamine levels prior to, during and for thirty minutes following the termination of the infusion. Rate of respiration and oxygen saturation levels did not alter significantly from baseline levels. When there was a cardiovascular decrease from base line levels it was on average 11% for systolic, 15% diastolic blood pressure and 14% for heart rate. Only plasma adrenaline and noradrenaline increased by 28 and 20%, 10 minutes following the bolus injectons. No dysphoria was experienced. This combined sedoanalgesic technique in nonstimulated human volunteers maintains spontaneous ventilation and may be considered as abalanced alternative to traditional conscious sedation or general anesthesia.