Clinical study of P_EtCO₂ in one-lung ventilation

Abstract

Fourty-eight patients (ASA physical status I — I) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV) and onelung ventilation (OLV) or TLV and OLV with a Bain cyclic system for CPAP on the side of operated lung. P_etCO₂ and PaCO₂ were measured after 30 min TLV, 30 min and 60 min OLV, and repeated TLV (R-TLV) 30 min after pulmonectomy, to evaluate the difference between P_etCO₂ and PaCO₂ in OLV and to observe the effect of abating hypoxemia and discharge of CO₂ in OLV with Bain system. Our results showed that the PaCO₂ and P_etCO₂ in different test groups were normal though the measured values in OLV were slightly higher than that in TLV (P <0. 05), and then they were recovered after R-TLV (P>0. 05). There was no significant difference between group 1. and 2. in OLV (P>0. 05). There was a close correlation between P_etCO₂ and PaCO₂(P<0.05). The differences of the calculated P_(a-et)CO₂ and radio of P_etCO₂/ PaCO₂ in different ventilation modes were not significant. Hypoxemia in OLV was corrected by Bain system, but the discharge of CO₂ was not affected. The results showed that measurement of P_et CO₂ as a non-invasive procedure can be commonly used to monitor OLV.

Keywords

CO₂ partial pressure / one-lung ventilation / non-invasive monitoring

References

[1] 1982, 3(2): 1

[2] 1983, 4(3): 138

[3] 1991, 11(5): 298

[4] FalkJ L, RachowE C, WeilM H. End-tidal carbon dioxide concentration during cardiopulmonary resuscitation. The New England Journal of Medicine, 1988, 318(10): 607-607

[5] GudipatiC V, WeilM H, BiseraJ, et al. . Expired carbon dioxide: a noninvasive monitor of cardiopulmonary resuscitation. Circulation, 1988, 77(1): 234-234

[6] 1994, 10 (6): 319

[7] Hess D R. A guide to understanding capnography. The BOC Group Inc, An educational service of Ohmeda, 1989, 9

[8] 1988, 8(5): 274

[9] Stanley T H and Sperry R J. Anesthesia and the lung. Kluwer Academic Publishers, 1989, 141