The effect of Diprivan (propofol) on phosphorylcholine surfaces during cardiopulmonary bypass--an in vitro investigation.

It is well known that extracorporeal surfaces have the ability to bind such drugs as fentanyl, nitroglycerine and propofol. Adsorption of the injectable anesthetic agent Diprivan (propofol) onto uncoated and heparin-coated extracorporeal surfaces during cardiopulmonary bypass (CPB) has been previously investigated; however, propofol adsorption onto synthetic-coated extracorporeal surfaces has not been published previously. The focus of this investigation was on the interaction of propofol and the synthetic biomimetic coating from the Sorin Group called Mimesys (phosphorylcholine (PC)). A randomized series of six in vitro experiments were done with propofol using both PC-coated circuits without arterial filters and those with arterial filters. The circuits were identical in all experiments and priming remained the same, with 750 mls of normal saline and 1250 mls of fresh bovine blood (hematocrit 41.0 +/- 1.0%). After circulation and collection of baseline samples, the first (low) dose of 4 mg (4000 mcg) of Diprivan 1% was added to the perfusate, followed by the second (high) dose of 40 mg (40,000 mcg) and the final challenge (extreme dose) of 356 mg (356,000 mcg) of Diprivan. Drug assay was done by an independent laboratory, using the standardized method of High Performance Liquid Chromatography (HPLC). Measurements of total propofol were done at baseline, 20 minutes, 40 minutes and 60 minutes after each injection. Oxygenator performance was also measured prior to the addition of propofol and repeated after exposure to 4 mg, 40mg and 356 mg propofol for 60 min, 120 min and 180 minutes of circulation. Results indicate that phosphorylcholine coating does not prevent the adsorption of propofol during extracorporeal circulation and the oxygenator's gas exchange ability is not affected by prolonged exposure to an extreme dose of the medication during high flow extracorporeal circulation.