Protective effect of carbon dioxide against bacterial peritonitis induced in rats

Does Helium Pneumoperitoneum Reduce the Hyperinflammatory Response in Septic Animals during Laparoscopy?

Background/Aim. An exacerbated reaction to peritoneal infection and attendant surgical procedures is characterized by an intense hyperinflammatory state, the magnitude of which is proportional to the severity of tissue injury. Laparoscopy generates lower levels of tissue damage compared with open surgery and should induce less pronounced immune responses. The aim of this study was to determine whether laparoscopy assisted by helium rather than carbon dioxide pneumoperitoneum would induce an attenuated inflammatory state in septic animals. Materials and Methods. Thirty-two Wistar rats were divided randomly into four equal groups, two of which were submitted to carbon dioxide or helium pneumoperitoneum-assisted laparoscopic cecal ligation and puncture (CLP) induced sepsis and subsequent abdominal lavage. Two control groups were submitted to identical laparoscopic procedures with carbon dioxide or helium as insufflator gas but without CLP. After 24 hours, serum levels of tumor necrosis factor alpha (TNF-α), interleukins 1 and 6 (IL-1 and IL-6, respectively), and cortisol were determined.

Systemic inflammation and immune response after laparotomy vs laparoscopy in patients with acute cholecystitis, complicated by peritonitis

AIM: To evaluate acute cholecystitis, complicated by peritonitis, acute phase response and immunological status in patients treated by laparoscopic or open approach.

METHODS: From January 2002 to May 2012, we conducted a prospective randomized study on 45 consecutive patients (27 women, 18 men; mean age 58 years). These subjects were taken from a total of 681 patients who were hospitalised presenting similar preoperative findings: acute upper abdominal pain with tenderness, involuntary guarding under the right hypochondrium and/or in the flank; fever higher than 38 °C, leukocytosis greater than 10 × 10⁹/L or both, and ultrasonographic evidence of calculous cholecystitis possibly complicated by peritonitis. These patients had undergone cholecystectomy for acute calculous cholecystitis, complicated by bile peritonitis. Randomly, 23 patients were assigned to laparoscopic cholecystectomy (LC), and 22 patients to open cholecystectomy (OC). Blood samples were collected from all patients before operation and at days 1, 3 and 6 after surgery. Serum bacteraemia, endotoxaemia, white blood cells (WBCs), WBC subpopulations, human leukocyte antigen-DR (HLA-DR), neutrophil elastase, interleukin-1 (IL-1) and IL-6, and C-reactive protein (CRP) were measured at 0, 30, 60, 90, 120 and 180 min, at 4, 6, 12, 24 h, and then daily (8 A.M.) until post-op day 6.

RESULTS: The two groups were comparable in the severity of peritoneal contamination as indicated by the viable bacterial count (open group = 90% of positive cultures vs laparoscopic group = 87%) and endotoxin level (open group = 33.21 ± 6.32 pg/mL vs laparoscopic group = 35.02 ± 7.23 pg/mL). Four subjects in the OC group (18.1%) and 1 subject (4.3%) in the LC group (P < 0.05) developed intra-abdominal abscess. Severe leukocytosis (range 15.8-19.6/mL) was observed only after OC but not after LC, mostly due to an increase in neutrophils (days 1 and 3, P < 0.05). This value returned to the normal range within 3-4 d after LC and 5-7 d after OC. Other WBC types and lymphocyte subpopulations showed no significant variation. On the first day after surgery, a statistically significant difference was observed in HLA-DR expression between LC (13.0 ± 5.2) and OC (6.0 ± 4.2) (P < 0.05). A statistically significant change in plasma elastase concentration was recorded post-operatively at days 1, 3, and 6 in patients from the OC group when compared to the LC group (P < 0.05). In the OC group, the serum levels of IL-1 and IL-6 began to increase considerably from the first to the sixth hour after surgery. In the LC group, the increase of serum IL-1 and IL-6 levels was delayed and the peak values were notably lower than those in the OC group. Significant differences between the groups, for these two cytokines, were observed from the second to the twenty-fourth hour (P < 0.05) after surgery. The mean values of serum CRP in the LC group on post-operative days (1 and 3) were also lower than those in the OC group (P < 0.05). Systemic concentration of endotoxin was higher in the OC group at all intra-operative sampling times, but reached significance only when the gallbladder was removed (OC group = 36.81 ± 6.4 ρg/mL vs LC group = 16.74 ± 4.1 ρg/mL, P < 0.05). One hour after surgery, microbiological analysis of blood cultures detected 7 different bacterial species after laparotomy, and 4 species after laparoscopy (P < 0.05).

CONCLUSION: OC increased the incidence of bacteraemia, endotoxaemia and systemic inflammation compared with LC and caused lower transient immunological defense, leading to enhanced sepsis in the patients examined.

CO2 pneumoperitoneum impact on early liver and lung cytokine expression in a rat model of abdominal sepsis

BACKGROUND

Experimental evidence suggests that laparoscopy could have reduced inflammatory sequelae compared with laparotomy following abdominal surgery for peritonitis. The aim of the present study is to investigate the possible beneficial effects of CO(2) insufflation on liver and lung expression of proinflammatory cytokines during sepsis.

METHODS

Cecal ligation and puncture (CLP) was induced in Sprague-Dawley rats, and 6 h later rats were randomly subjected to CO(2) pneumoperitoneum (5-7 mmHg) or to laparotomy for 1 h. At the end of the CO(2) pneumoperitoneum or laparotomy procedures, animals were sacrificed, and liver and lung were removed and stored for molecular and histological analysis.

RESULTS

Liver and lung expression of proinflammatory cytokines was significantly reduced in animals subjected to CO(2) pneumoperitoneum compared with laparotomy. In particular, tumor necrosis factor-alpha (TNF-α) protein expression was significantly reduced (p < 0.05) following CO(2) pneumoperitoneum compared with laparotomy procedures. Interleukin (IL)-6 protein expression was accordingly, markedly reduced (p < 0.05) following CO(2) pneumoperitoneum. Histological analysis showed a reduced inflammatory infiltrate in liver and lung from animals subjected to CO(2) pneumoperitoneum compared with laparotomy.

CONCLUSIONS

Our results support the hypothesis that laparoscopic procedures reduce the inflammatory cascade, following peritoneal sepsis, via reduced expression of proinflammatory cytokines.