Impact of peritoneal lavage temperature during laparotomy in a preterm peritonitis mouse model using cecal slurry

Peritoneal lavage (PL) during laparotomy is a treatment option for preterm bacterial peritonitis; however, its efficacy remains controversial. We investigated the effects of PL temperature during laparotomy on survival in a cecal slurry (CS)-induced preterm peritonitis mouse model. Four-day-old pups that were intraperitoneally administered 1.8 mg/g CS solution underwent laparotomy through a 5-mm transverse incision 2 h after CS injection (sham group). An additional PL was established during laparotomy with 500 µl of 25°C, 35°C, and 45°C sterile saline, respectively (PL25, PL35, and PL45 groups). Postoperative 7-day survival, body temperature, and plasma and ascites cytokine concentrations were evaluated for each group. Postoperative 7-day survival rates in the sham, PL25, PL35, and PL45 groups were 52.9%, 56.3%, 33.3%, and 18.2% (p=0.097), respectively. Median BT changes between before and after surgery were −1.85°C, −2.30°C, −3.40°C, and −1.80°C for each group (p=0.0065). The median ascites MCP-1 and IL-6 concentrations (pg/ml) at postoperative 2 h were 32,432, 16,244, 6279, and 5100 (p=0.049) and 22,346, 11,537, 5519, and 4535 (p=0.076), and plasma MCP-1 and IL-6 concentrations (pg/ml) were 68,687, 16,327, 9277, and 1868 (p=0.084) and 112,290, 14,415, 11,403, and 4113 (p=0.123) for each group, respectively. Postoperative 7-day survivals were slightly improved by PL with 25°C sterile saline, however decreased by increasing PL temperatures to 35°C and 45°C in a CS-induced preterm peritonitis mouse model. As PL temperature was increased, both plasma and ascites MCP-1 and IL-6 concentrations tended to be suppressed, suggesting to decrease postoperative survivals.