Carbon dioxide absorption during extraperitoneal and transperitoneal endoscopic hernioplasty

Transabdominal preperitoneal (TAPP) or total extraperitoneal (TEP) hernioplasty are probably associated with differing degrees of CO(2) absorption which can influence anesthetic management and perioperative morbidity. We studied 20 patients with either TAPP or TEP for perioperative CO(2) absorption (calculated from CO(2) elimination and metabolic CO(2) production) and ventilatory changes required to maintain normocapnia (blood gas analyses). CO(2) absorption reached plateau values in the TAPP group, but increased over time in the TEP group. Median CO(2) absorption during insufflation was 61 mL/min (range 43-78) for TAPP and 114 mL/min (range 75-178) for TEP, with a maximum of 114 mL/min (range 75-178) for TAPP and 258 mL/min (range 112-585) for TEP. Median minute ventilation (V(E)) required for maintaining normocapnia was 9. 5 L/min (range 7.7-11.5) for TAPP and 12.9 L/min (range 9.0-22.6) for TEP (P: < 0.01). Seven patients in the TEP group required over 18 L/min V(E), although no patient in the TAPP group required more than 14 L/min V(E). All patients in the TEP group had significant subcutaneous emphysema resulting in one case of delayed tracheal extubation. We conclude that CO(2) absorption is consistently less with TAPP.

The greater magnitude of carbon dioxide absorption during total extraperitoneal hernioplasty puts an additional load on the lungs and could pose a risk for patients with chronic lung disease who might be unable to eliminate excess carbon dioxide.