Intravenous anaesthesia in the 1990s: a view from Europe

Propofol infusion anaesthesia and immune response in minor surgery

This study was set up to evaluate the effects of propofol infusion anaesthesia on immunological function in minor surgery. Twenty-seven patients (median age 51 years, ASA 1-2) scheduled for minor breast surgery were randomly assigned to two groups. Anaesthesia was induced in group 1 with propofol 2.5 mg.kg-1 and maintained with propofol 12 mg.kg-1 x h-1 and 30% O2 in air, whereas in group 2 anaesthesia was induced with thiopentone 4 mg.kg-1 and maintained with 70% N2O in O2. Fentanyl and vecuronium were used in both groups. The percentages of T cells (p < 0.001), B cells (p < 0.01) and memory T cells increased (p < 0.01) in both groups. T helper cell percentages increased in the propofol but not in the thiopentone group (p < 0.05). The percentages of natural killer cells decreased from pre-induction values in both groups (p < 0.001). No changes were seen in lymphocyte proliferative responses. Minor breast surgery under propofol or conventional combined anaesthesia had only minor effects on the immune response. The higher percentage of T helper cells after propofol anaesthesia compared to conventional combined anaesthesia is beneficial, but its clinical importance remains to be determined.

Propofol emulsion reduces proliferative responses of lymphocytes from intensive care patients

OBJECTIVE

To test propofol lipid emulsion formulation for its immunosuppressive effects.

DESIGN

Propofol lipid emulsion and the emulsion alone were tested at increasing concentrations and compared to initial values and between each other. Propofol alone could not be tested due to its insolubility into the culture medium.

PATIENTS AND PARTICIPANTS

Lymphocytes from 12 surgical intensive care (ICU) patients (median APACHE score 16 and median TISS score 28) and 12 healthy volunteers.

MEASUREMENTS

Phytohaemagglutinin-, concanavalin A- and pokeweed mitogen-induced lymphocyte proliferative responses were measured in the presence of increasing concentrations of propofol lipid emulsion formulation or the lipid emulsion.

RESULTS

Lymphocyte proliferative responses from ICU patients were in general on a lower level than in the volunteers. The propofol lipid emulsion formulation (Diprivan) decreased pokeweed mitogen-induced proliferative responses of lymphocytes from ICU patients at propofol concentrations found in the circulation (1-10 micrograms/ml) and the lipid emulsion alon at 100 micrograms/ml triglyceride concentrations while the other mitogen-induced responses were not affected. No changes were observed in the mitogen-induced responses of lymphocytes from healthy volunteers.

CONCLUSIONS

Propofol emulsion formulation decreased in surgical intensive care patients pokeweed mitogen-induced lymphocytic responses in vitro at clinically found concentrations, indicating the need for further studies to test B-lymphocyte functions and T-B-lymphocyte co-operation during propofol lipid emulsion administration. (ICU) patients is widespread because of its good control of sedation. Propofol is currently administered in fat emulsion which is considered immunosuppressive during bolus injection or rapid infusion. Therefore, effects of a propofol fat emulsion formulation on proliferative responses of lymphocytes were studied in blood samples obtained from healthy volunteers and ICU patients known to be immunosuppressed.