Laparoscopic surgery is replacing conventional surgical techniques due to its many advantages. However the possibility of respiratory complications during CO₂-induced pneumoperitoneum remain. Tracheal gas insufflation (TGI) has been shown to be a useful adjunct to mechanical ventilation in hypercapneic patients. This study investigated the effectiveness of TGI in reducing the PaCO₂ level in hypercapneic patients during laparoscopic surgery without increasing the peak inspiratory pressure (PIP) and usefulness of a Univent tube® as a device for TGI.

Twenty-four patients who were scheduled to undergo gynecological laparoscopic surgery, were enrolled in this study. Anesthesia was induced and maintained with propofol, rocuronium and N₂O-O₂-sevoflurane. The suction port of the endobronchial blocker of the Univent tube® was used for the path of TGI. Data including the ABGA and respiratory parameters were measured three times, the pre-CO₂ peritoneum (pre-CO₂ pneumoperitoneum point, PCP), 15 min after CO₂ peritoneum (after-CO₂ pneumoperitoneum point, ACP) and after 15 min TGI (TGI point, TGIP).

At ACP, the PaCO₂ and PIP had increased more significantly than PCP. After TGI, the PaCO₂ was decreased more significantly than ACP, but the PIP did not increased.

TGI is a useful adjunct to mechanical ventilation in hypercapneic patients during laparoscopic surgery, and a univent tube® is an economic and convenient device for TGI.