The Effects of Low-Pressure Carbon Dioxide Pneumoperitoneum on Cerebral Oxygenation and Cerebral Blood Volume in Children

Abstract

We examined the effects of low-pressure carbon dioxide pneumoperitoneum on regional cerebral oxygen saturation (ScO2) and cerebral blood volume (CBV) in children. Fifteen children, ASA I–III, scheduled for laparoscopic fundoplication, were investigated in the head-up position (10°) and ventilated to a baseline end-tidal CO2 (Petco2) between 25 and 33 mm Hg. Ventilatory settings remained unchanged during the operation. ScO2 and CBV were assessed with near-infrared spectroscopy and recorded together with end-tidal and arterial carbon dioxide (Paco2) at 5 time points: before insufflation, 30, 60, and 90 min after the start of CO2 insufflation, and 10 min after desufflation. The intraabdominal pressure was kept between 5 and 8 mm Hg. During insufflation, Petco2 increased from 30.0 ± 2.8 to 38.3 ± 5.1 mm Hg (P < 0.001) and Paco2 increased from 32.0 ± 4.7 to 40.4 ± 5.9 mm Hg (P < 0.001). ScO2 increased by 15.7% ± 8.8% (from 61 ± 9 to 70 ± 9 arbitrary units ) (P < 0.001). CBV increased by 4.6% ± 8.8% (from 123 ± 66 to 128 ± 66 arbitrary units [P = 0.048]). After desufflation, Petco2 and Paco2 decreased, but did not return to preinsufflation values. ScO2 and CBV also decreased after desufflation. In conclusion, hyperventilation and the head-up position before CO2 insufflation are not sufficient to prevent the CO2-mediated cerebral hemodynamic effects of low-pressure pneumoperitoneum (5–8 mm Hg) in children.