title: 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 (ScO(2)) 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 CO(2) (PETCO(2)) between 25 and 33 mm Hg. Ventilatory settings remained unchanged during the operation. ScO(2) and CBV were assessed with near-infrared spectroscopy and recorded together with end-tidal and arterial carbon dioxide (PaCO(2)) at 5 time points: before insufflation, 30, 60, and 90 min after the start of CO(2) insufflation, and 10 min after desufflation. The intraabdominal pressure was kept between 5 and 8 mm Hg. During insufflation, PETCO(2) increased from 30.0 plus minus 2.8 to 38.3 plus minus 5.1 mm Hg (P < 0.001) and PaCO(2) increased from 32.0 plus minus 4.7 to 40.4 plus minus 5.9 mm Hg (P < 0.001). ScO(2) increased by 15.7% plus minus 8.8% (from 61 plus minus 9 to 70 plus minus 9 arbitrary units ) (P < 0.001). CBV increased by 4.6% plus minus 8.8% (from 123 plus minus 66 to 128 plus minus 66 arbitrary units [P = 0.048]). After desufflation, PETCO(2) and PaCO(2) decreased, but did not return to preinsufflation values. ScO(2) and CBV also decreased after desufflation. In conclusion, hyperventilation and the head-up position before CO(2) insufflation are not sufficient to prevent the CO(2)-mediated cerebral hemodynamic effects of low-pressure pneumoperitoneum (5--8 mm Hg) in children.
  
  
  CONCLUSIONS
  Peritoneal CO(2) absorption during laparoscopic surgery causes hypercapnia and CO(2)-mediated cerebral hemodynamic effects. Hyperventilation and the head-up position before CO(2) insufflation is not sufficient to counteract these effects of low-pressure pneumoperitoneum (5--8 mm Hg) in children.
authors.affiliation: Department of Anesthesiology, University Medical Centre Utrecht, The Netherlands. e.e.c.dewaal@azu.nl
authors.forename: Eric E C
authors.initials: EE
authors.lastname: de Waal
authors.forename: Jaap W
authors.initials: JW
authors.lastname: de Vries
authors.forename: Cas L J J
authors.initials: CL
authors.lastname: Kruitwagen
authors.forename: Cor J
authors.initials: CJ
authors.lastname: Kalkman
mesh_terms: D001810:Blood Volume; D001921:Brain / Q000378:metabolism*; D002245:Carbon Dioxide / Q000494:pharmacology*; D002560:Cerebrovascular Circulation; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D011028:Pneumoperitoneum, Artificial
chemical_list: D002245:Carbon Dioxide; D010100:Oxygen