To investigate the effects of different pneumoperitoneum pressures on circulatory function in miniature pigs during laparoscopic surgery, and to select appropriate pneumoperitoneum pressure to complete laparoscopic surgery.

A total of twenty-four Bama miniature pigs with 25-30 kg weight were randomly divided into 4 groups: group A, B, C and D. The pneumoperitoneum pressure of 10, 13, 15, 17 mmHg (1.330, 1.729, 1.995, 2.261 kPa) was used for laparoscopic operation, heart rate (HR), mean arterial pressure (MAP) and arterial blood gas were monitored at different time points.

In terms of MAP, there was no significant change in group A, but it increased significantly in group B at 30 min and 180 min, and decreased significantly in group C and D after 30 min of pneumoperitoneum (P<0.01). HR in the four groups increased gradually after pneumoperitoneum, and the greater the pneumoperitoneum pressure, the more obvious the impact. PaO₂ in the four groups had no significant changes from the beginning of pneumoperitoneum to 60 minutes, but decreased in group A, C and D at 120 minutes (P<0.05). PaCO₂ increased after pneumoperitoneum, and with the increasing of PaCO₂, blood acid-base value decreased. There were significant differences among the four groups (P<0.01).

In the general laparoscopic surgery, pneumoperitoneum can affect the circulatory function of 25-30 kg miniature pigs. The pneumoperitoneal pressure should be controlled in the range of 10-13 mmHg and should not exceed 15 mmHg, so as to ensure the operative field of vision and reduce the impact of pneumoperitoneum on the body.