Do volatile inhalation anesthetics modify the immune response in surgical patients?

ABSTRACT

Anesthesia and surgery suppresses immune response which can reveal itself in complicated forms like allergy, infections etc. This impact can further increase the morbidity of surgical procedures. A prospective study was designed in minor surgical patients to elucidate the immunological responses and compare the immunological end-results of inhalation anesthetics halothane, isoflurane and sevoflurane with the aim of clarifying most suitable agent providing less immune changes. Forty five adult male patients without any immunological compromise and undergoing minor surgery [herniorraphy] were included. After the same induction technique, patients received halothane based general anesthesia GA [n 15], isoflurane based GA [n 15] or sevoflurane based GA [n 15]. Laboratory assessment included stress hormones [epinephrine, norepinephrine and cortisol], cytokines [interleukin IL-2, IL-6 and IL-10], and cellular elements [white blood count, lymphocytes, T-lymphocytes subgroups CD4, CD8 and natural killer NK-cells]. The blood samples were withdrawn just preoperative, 30 min after induction, just after recovery, 6 h and 24 h postoperative. There were significant increases in plasma epinephrine level [P < 0.05], norepinephrine level [P < 0.01] and plasma cortisol level [P < 0.01] in all groups. Isoflurane anesthesia was associated with significantly higher concentrations of cortisol when compared to sevoflurane and halothane. In all groups, interleukin IL-2, IL-6 were significantly increased after surgery [each group P < 0.05], While IL-10 did not change significantly. Leukocyte counts were unaffected in all groups. While lymphocytes significantly decreased in all groups, it decreased significantly in isoflurane group in relation to halothane and sevoflurane. Lymphocyte subgroups CD4 and CD8 measurements were stable. NK cells significantly decreased in all groups, it decreased significantly in isoflurane group in relation to halothane and sevoflurane. In the clinical setting of a low stress procedure, the use of isoflurane anesthesia apparently increases cortisol level, this phenomenon was associated with less favorable metabolic and immune response when compared with sevoflurane or halothane. Further studies are required to verify whether sevoflurane anesthesia might maintain such advantages in more critical surgical procedures on severely ill, immunocompromised and/or malnourished patients