Development of atelectasis and arterial to end-tidal PCO2-difference in a porcine model of pneumoperitoneum
2009 (English)In: British Journal of Anaesthesia, ISSN 0007-0912, E-ISSN 1471-6771, Vol. 103, no 2, 298-303 p.Article in journal (Refereed) Published
BACKGROUND: Intraperitoneal insufflation of carbon dioxide (CO2) may promote collapse of dependent lung regions. The present study was undertaken to study the effects of CO2-pneumoperitoneum (CO2-PP) on atelectasis formation, arterial oxygenation, and arterial to end-tidal PCO2-gradient (Pa-E'(CO2)). METHODS: Fifteen anaesthetized pigs [mean body weight 28 (SD 2) kg] were studied. Spiral computed tomography (CT) scans were obtained for analysis of lung tissue density. In Group 1 (n=5) mechanical ventilation (V(T)=10 ml kg (-1), FI(O2)=0.5) was applied, in Group 2 (n=5) FI(O2) was increased for 30 min to 1.0 and in Group 3 (n=5) negative airway pressure was applied for 20 s in order to enhance development of atelectasis. Cardiopulmonary and CT data were obtained before, 10, and 90 min after induction of CO2-PP at an abdominal pressure of 12 mmHg. RESULTS: Before CO2-PP, in Group 1 non-aerated tissue on CT scans was 1 (1)%, in Group 2 3 (2)% (P<0.05, compared with Group 1), and in Group 3 7 (3)% (P<0.05, compared with Group 1 and Group 2). CO2-PP significantly increased atelectasis in all groups. PaO2/FI(O2) fell and venous admixture ('shunt') increased in proportion to atelectasis during anaesthesia but CO2-PP had a varying effect on PaO2/FI(O2) and shunt. Thus, no correlation was seen between atelectasis and PaO2/FI(O2) or shunt when all data before and during CO2-PP were pooled. Pa-E'(CO2), on the other hand correlated strongly with the amount of atelectasis (r2=0.92). CONCLUSIONS: Development of atelectasis during anaesthesia and PP may be estimated by an increased Pa-E'(CO2).
Place, publisher, year, edition, pages
2009. Vol. 103, no 2, 298-303 p.
lung, atelectasis, measurement techniques, computed tomography, model, pig, partial pressure, Pa-Pe'(CO2) ratio, Surgery, laparoscopy
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:uu:diva-113070DOI: 10.1093/bja/aep102ISI: 000268107800023PubMedID: 19443420OAI: oai:DiVA.org:uu-113070DiVA: diva2:289529