Low-dose ketamine pretreatment reduces oxidative damage and inflammatory response following CO2 pneumoperitoneum in rats

Purpose The duration of pneumoperitoneum during laparoscopic procedures may contribute to post-surgical oxidative stress. Previous studies have shown that low-dose ketamine, an anesthetic with anti-inflammatory properties, protects various organs from ischemia-reperfusion injury. This study investigated the effects of low-dose ketamine on the overproduction of oxidants and the tissue damage caused by intra-abdominal pressure during CO2 pneumoperitoneum. Methods Male Sprague Dawley rats received a CO2 pneumoperitoneum of 15 mmHg and preceded by either low-dose ketamine (KP1, 5 mg/kg; KP2, 10 mg/kg) or 0.9% saline (PR, 3 ml). General anethesia was provided by pentobarbital and sevoflurane. The control group (CR) received an intraperitoneal saline injection and sham surgery. Three hours after pneumoperitoneum, serum concentrations of interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA), superoxide dismutase (SOD) and intestinal fatty acid binding protein (iFABP) were measured and liver, kidney, lung, and intestine were evaluated for tissue damage. Results The highest plasma MDA, TNF-α, IL-6 and iFABP values were observed at T1 (after 3 hours of pneumoperitoneum) in the PR group, followed by the KP1, KP2, and CR groups (P < 0.01). SOD concentrations showed an opposite trend and were highest in the CR group, followed by the KP2, KP1, and PR groups (P < 0.01). TNF-α concentration was significantly lower in the KP2 than the KP1 group (P < 0.05). Histopathologic scoring of organ sections demonstrated the lowest scores in the KP2 group, followed by the KP1 and PR groups, in an increasing order (P < 0.05). Conclusion Pretreatment with low-dose ketamine before general anaesthesia protects against potential oxidative damage and inflammatory response caused by CO2 pneumoperitoneum.