In vitro effect of clinical propofol concentrations on platelet aggregation

The inhibitory effect of propofol on platelet aggregation remains unclear, and studies on the subject disagree. Furthermore, although propofol infusions are widely used for general anesthesia and as sedatives for patients in intensive care units, little information is available on its concentration- and time-related effects on platelet aggregation. Here, the authors investigated the in vitro effect of propofol, at concentrations required for sedation and general anesthesia, on platelet aggregation after 1, 2, or 3 h. Blood from healthy volunteers (n = 9) was incubated at propofol plasma concentrations of 0, 2, 4, and 10 μg/mL in a water bath at 37°C. Platelet aggregation was measured using a platelet function analyzer (PFA-100) after 1, 2, or 3 h of incubation. Times to occlude collagen/epinephrine (CEPI) or collagen/adenosine 5'-diphosphate (CADP)-coated membranes (closure times, CTs) were measured. The CEPI and CADP CTs of non-incubated blood were 125.6 ± 19.5 s and 93.0 ± 12.2 s, respectively, and no significant difference in CEPI CTs was observed at propofol plasma concentrations of 0, 2, 4, and 10 μg/mL after incubation for 1, 2, or 3 h. CADP CTs were comparable at propofol concentrations of 0, 2, 4, and 10 μg/mL at each incubation time. These findings suggest that propofol at concentrations required for sedation and general anesthesia has no inhibitory effect on platelet aggregation after 3 h of incubation.