Peripheral blood flow with a sedative propofol-ketamine combination

When ketamine is supplemented to propofol sedation it provides cardiorespiratory stability whilst each agent attenuates the undesirable effects of the other. The aim of this study was to examine the effects on peripheral blood flow with a balanced sedative propofol-ketamine combination. Propofol was administered to eleven ASAI volunteers (mean age 25.6 years and mean weight 62.3 kg) at a loading dose of 1 mg/kg over two minutes after which 0.7 mg/kg of ketamine was administered over a further two minutes. This was then followed by a propofol-ketamine combination of 5 mg/kg of propofol mixed with 0.7 mg/kg of ketamine and was infused via micro-mini drip over one hour. Routine clinical monitoring was applied throughout the entire study period. Peripheral blood flow was measured non-invasively with an ALF21D laser Doppler flowmeter (Advance. Tokyo, Japan). The probe was attached to the ventral surface of the pad of the index finder and remained in line with the patient's body. There was a significant increase (p < 0.05) in peripheral blood flow, with an average increase of 51% throughout the infusion in comparison to baseline levels. Blood flow returned to baseline levels twenty minutes after the discontinuation of the infusion. In comparison systolic blood pressure decreased by only 5% over the same period and diastolic pressure by 9%.