Improved ventilation-perfusion matching by abdominal insufflation (pneumoperitoneum) with CO2 but not with air
2013 (English)In: Minerva Anestesiologica, ISSN 0375-9393, Vol. 79, no 6, 617-625 p.Article in journal (Refereed) Published
Background. Pneumoperitoneum (PP) by CO2-insufflation causes atelectasis however with maintained or even improved oxygenation. We studied the effect of abdominal insufflation by carbon dioxide (CO2) and air on gas exchange during PP. Methods. Twenty-seven anesthetized pigs were studied during PP with insufflations to 12 mmHg by either 1/CO2, 2/ air or 3/CO2 during intravenous nitroprusside infusion (SNP) (N.=9 in each group). In 3 pigs in each group, gamma camera technique (SPECT) was used to study ventilation and perfusion distributions, in another 6 pigs an inert-gas technique (MIGET) was used for assessing ventilation-perfusion matching (V-A/Q). Measurements were made during anesthesia before and after 60 minutes of PP. Results. CO2-PP caused a shift of blood flow away from dependent, non-ventilated (atelectatic) to ventilated regions. Air-PP caused smaller, and SNP-PP even less shift of lung blood flow. Shunt decreased luring CO2-PP (6+/-1% compared to baseline 9+/-2%, P<0.05), did not change during Air-PP (10+/-2%) and increased during SNP-PP (16+/-2%, P<0.05). PaO2 increased from baseline 35+/-2 to 41+/-3 kPa during CO2-PP and decreased to 32+/-3 kPa during Air-PP and to 27+/-3 kPa during SNP-PP (P<0.05 for all three comparisons). PaCO2 increased during CO2- and SNP-PP. Conclusion. CO2-PP enhanced the shift of blood flow towards better ventilated areas of the lung compared to Air-PP and SNP blunted the effects seen with CO2-PP. SNP may thus have blunted and CO2 potentiated vasoconstriction, by hypoxic pulmonary vasoconstriction or another mechanism.
Place, publisher, year, edition, pages
2013. Vol. 79, no 6, 617-625 p.
Pulmonary gas exchange, Ventilation, Surgical procedures, operative, Laparoscopy, Carbon dioxide, Models, animal
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-206665ISI: 000322424400007OAI: oai:DiVA.org:uu-206665DiVA: diva2:645095