In Systemic Inflammatory Response Syndrome (SIRS) model in rabbits we aim to investigate the relationship between increased intraabdominal pressure (IAP) and lung compliance during mechanical ventilation.

Twenty-four New Zealand rabbits were randomly divided into three groups (n = 8). After sedation with intramuscularly ketamine (50 mg/kg): In group 1: Laparotomy and single cecum puncture was done and, after insertion of an intraabdominal catheter, the abdomen was closed. In group 2: Laparotomy was done and after insertion of an intraabdominal catheter, the abdomen was closed. In group 3: It was the control group. After sedation, nothing was done.

In group 1 and 2, after 1 hour of abdomen closure and in group 3 after 1 hour of sedation, tracheostomy was performed and endotracheal tube was inserted. The rabbits were curarized by atracuriým (0.5 mg/kg, intramuscularly), and ventilated with PC mode for 3 hours and the parameters of ventilation were FiO₂ = 1.0, PIP = 18 cmH₂O, PEEP = 5 cmH₂O, RR = 80 breaths/min. Compliance and IAP values were recorded every 30 min. Data were compared by Mann-Whitney Utest. P <0.05 was considered to indicate statistical significance.

IAP levels in group 2 were found to be higher than group 3 (P <0.01). However when lung compliance values were compared between groups, no significant differences was encountered. And lung compliance values were found to be significantly decreased when compared to initial values in all groups at the end of the study (P <0.05).

In this experimental SIRS model, at the very beginning, increased IAP values does not seem to effect lung compliance measurements during mechanical ventilation.