Immune perturbations in patients along the perioperative period: alterations in cell surface markers and leukocyte subtypes before and after surgery.

BACKGROUND: Surgery renders patients susceptible to life-threatening complications, including infections, multiple organ failure, and presumably cancer metastases. Surgery-induced immune perturbations were suggested to contribute to such deleterious effects, but also to facilitate post-injury healing. Preoperative psychological and physiological stress responses may contribute to these immune perturbations, and could thus jeopardize patients even before surgery. The current study assessed the effects of various operations on an array of immune indices during the perioperative period. To qualify immune changes before surgery, patients' immune status was also compared to that of healthy controls. METHODS: A total of 81 subjects (operated patients and healthy controls) provided up to five daily blood samples during the perioperative period, for assessment of leukocyte subtypes (granulocytes, monocytes, Tc, Th, NK, NKT, CD4+CD25+, CD8(bright)CD4(dim), and B cells) and their surface markers (HLA-DR and LFA-1). RESULTS: Even before surgery patients displayed immune perturbations, including reduced lymphocyte HLA-DR expression and increased monocyte LFA-1 expression. Following surgery, we recorded a reduction in lymphocyte numbers that was subtype specific, increased granulocyte numbers, and reduced expression of HLA-DR by lymphocytes and monocytes. Finally, no significant associations were found between alteration in leukocyte numbers and cell surface markers (although these indices showed high correlations with other variables), implying differential mediating mechanisms. CONCLUSION: Several immune alterations are manifested prior to surgery, and contribute to the marked postoperative changes, which are commonly interpreted as immune suppression. We discuss the possible adaptive and maladaptive nature of these perturbations in the context of natural injury, stress, and surgery.

Blood rheology in PCA and PCEA after total knee arthroplasty.

The rheological events in 2 groups of patients undergoing total knee arthroplasty were compared--15 patients were given general anesthesia and controlled their postoperative pain applying intravenous patient-controlled analgesia; 17 individuals received combined spinal-epidural anesthesia and controlled their postoperative pain by patient-controlled epidural analgesia (PCEA). Twenty-four and 48 hours after surgery, the patient-controlled analgesia group showed a significant increase in whole-blood viscosity at the 3 shear rates (P < .01), as well as in relative viscosity at both periods (P < .001 and .01, respectively). Similar findings were observed for red blood cell aggregation (P < .001) and fibrinogen level (P < .001). These values were less expressed in the PCEA group, particularly 48 hours after surgery (P < .01), and the patients showed lower scores on the visual analog pain scale. The better results observed in the PCEA group favor the application of epidural anesthesia and PCEA analgesia in patients undergoing total knee arthroplasty.

Effect of a BIOcocktail on the immune response at the early postoperative period in mice.

Since human subjects and laboratory animals may develop impaired immune response during surgery and the postoperative period, efforts have been made to preserve normal immune functions following surgery by the administration of nutritional supplements and probiotics. The present study was designed to examine the effect of a new nutritional supplement, BIOcocktail, on immune parameters in mice exposed to surgery. Forty mice were assigned to 4 groups containing 10 animals each. Two control groups (with and without subsequent sham laparotomy) were given tap water for 45 min every day for 2 weeks. The remaining 2 groups, with and without laparotomy, received BIOcocktail given orally for the same period of time. The proliferative response of splenic cells (splenocytes) stimulated with phytohemagglutinin (PHA), concanavalin A (Con A) and lipopolysaccharide (LPS) was determined by [3H]thymidine uptake. Cytokine levels were measured in splenocyte supernatants and sera using enzyme-linked immunosorbent assay (ELISA) kits. Natural killer cell activity of splenocytes was evaluated by 51Cr-release assay. Laparotomy, without BIOcocktail administration, was followed by a decreased proliferative response of splenocytes to PHA, Con A, and LPS and an increase in interleukin (IL)-6 serum level. In addition, a decreased secretion of IL-1beta, IL-12 and tumor necrosis factor (TNF)-alpha by the splenocytes was observed. Mice treated with BIOcocktail before laparotomy maintained a preoperative level of splenocyte proliferative response and serum concentrations of IL-12. It is concluded that BIOcocktail administered to mice for 2 weeks before operation resulted in the preservation of T- and B-cell proliferative response to mitogens and in the prevention of postoperative decrease in IL-12 serum level.

Rheological events following laparoscopic and conventional laparotomy.

Laparoscopic surgery has become a widely used procedure with many advantages compared to conventional laparotomy. Although rare, this technique is not entirely absent from clinical hazards and particularly thromboembolic events. This complication is due to activation of the coagulation cascade, as well as factors that may cause alterations in blood rheology. Apart from high hematocrit, presence of abnormal proteins and elevated fibrinogen level, the type of anesthesia, temperature, and increased intra-abdominal pressure following CO(2) insufflation may affect blood viscosity. Therefore, the objective of the study was to compare rheological events in 17 patients undergoing laparoscopic surgery to those in 15 patients who underwent laparotomy. Both groups of patients did not show any complications during the early and late post-operative period. The values of whole blood viscosity in patients undergoing laparoscopy did not differ from those in patients treated by laparotomy. A slight, although significant decrease in plasma viscosity and red blood cell aggregation was observed in patients who underwent laparotomy. The results suggest that the benefits of laparoscopic surgery in the present series were not affected by alterations in blood and plasma viscosity, as well as in red blood cell aggregation.