Effects of pneumoperitoneum and positioning on respiratory mechanics in chronic obstructive pulmonary disease patients during Nissen fundoplication.

Objective: The aim of this study was to evaluate the effects of pneumoperitoneum and patient positioning on respiratory mechanics and blood gases in chronic obstructive pulmonary disease (COPD) patients during laparoscopic Nissen fundoplication.

Methods: After the approval of the Ethical Committee, 32 patients were divided into 2 groups as COPD patients (n=16) and normal patients (n=16). Dynamic respiratory compliance (Cdyn), airway resistance, and peak inspiratory pressure were monitored. Measurements were made in 5 time points: after intubation (intubation), Trendelenburg position (Trendelenburg), during laparoscopic Nissen fundoplication surgery after pneumoperitoneum with the Fowler position (Fowler), right before the desufflation with Fowler position (Fowler-end), and after the desufflation in supine position (supine). Samples of arterial blood gases were collected at the same periods.

Results: At all periods, there was a significant decrease in Cdyn and arterial oxygen pressure in 2 groups. Although pneumoperitoneum did not exist during Trendelenburg position, the Cdyn (38+/-13 mL cm H2O(-1)) found to be significantly decreased in COPD patients. In 2 groups, the lowest Cdyn value detected during the Fowler-end period was 43+/-8 mL cm H2O(-1) in control group and 34+/-11 mL cm H2O(-1) in COPD group. Whereas the pH decreased at Fowler, Fowler-end, and supine period, arterial carbon dioxide pressure increased (P<0.05). There was no difference for the other parameters.

Conclusions: In COPD patients, Trendelenburg position has negative effect on respiratory mechanics. Pneumoperitoneum and other positions have similar effect on respiratory mechanics in COPD and control patients.