Effect of premedicants, intravenous anaesthetic agents and local anaesthetics on phagocytosis in vitro

Abstract

Intact leucocyte function is essential for the body's defense against infection. Any depression of leucocyte migration, phagocytosis and ability to kill invading organisms is likely to enhance morbidity and mortality from infection in the postoperative period. Although volatile anaesthetic agents have been shown to influence the leucocyte function adversely, yet the effects of non-volatile anaesthetic agents and other allied drugs on the leucocyte phagocytic activity have not been explored. Therefore, the effects of premedicants (morphine, meperidine, diazepam), intravenous induction agents (thiopentone, methohexitone, alfathesin, and ketamine), local anaesthetic agents (lidocaine, procaine, and bupivacaine), muscle relaxants (succinylcholine and tubocurarine), and other drugs (prednisolone, furosemide, aspirin, epinephrine and chlorpromazine), on the phagocytic activity of leucocytes was investigated in vitro. Leucocytes were separated from the blood samples taken from healthy human volunteers, treated with 10-2 to 10-6 molar concentrations of the drug under investigation and subsequently incubated at 37°C along with heat inactivated staphylococcus aureus to allow phagocytosis. Following incubation for one hour, cell smears were prepared and stained with haematoxylin. The number of bacteria ingested by one hundred leucocytes on the control and the drug treated cell smears were counted. The difference in phagocytosis between the control and the test cells when examined by analysis of variance revealed a statistically significant dose dependent inhibition of phagocytic activity under the influence of premedicants, intravenous induction agents, local anaesthetic agents (except bupivacaine), diazepam and chlorpromazine (P < 0.005). In contrast, muscle relaxants and other drugs failed to inhibit the leucocyte phagocytic activity in vitro. These observations indicate that different anaesthetic agents can adversely effect the leucocyte function in vitro; however, the mechanisms by which these agents produce a depression of phagocytosis are not clear at present. © 1981 Canadian Anesthesiologists.