Noninvasive monitoring of PaCO₂ during one-lung ventilation and minimal access surgery in adults: End-tidal versus transcutaneous techniques

Abstract

Background:Previous studies have suggested that end-tidal CO2 (ET-CO2) may be inaccurate during one-lung ventilation (OLV). This study was performed to compare the accuracy of the noninvasive monitoring of PCO2 using transcutaneous CO2 (TC-CO2) with ET-CO2 in patients undergoing video-assisted thoracoscopic surgery (VATS) during OLV.Materials and Methods:In adult patients undergoing thoracoscopic surgical procedures, PCO2 was simultaneously measured with TC-CO2 and ET-CO2 devices and compared with PaCO2.Results:The cohort for the study included 15 patients ranging in age from 19 to 71 years and in weight from 76 to 126 kg. During TLV, the difference between the TC-CO2 and the PaCO2 was 3.0 ± 1.8 mmHg and the difference between the ET-CO2 and PaCO2 was 6.2 ± 4.7 mmHg (P=0.02). Linear regression analysis of TC-CO2 vs. PaCO2 resulted in an r2 = 0.6280 and a slope = 0.7650 ± 0.1428, while linear regression analysis of ET-CO2 vs. PaCO2 resulted in an r2 = 0.05528 and a slope = 0.1986 ± 0.1883. During OLV, the difference between the TC-CO2 and PaCO2 was 3.5 ± 1.7 mmHg and the ET-CO2 to PaCO2 difference was 9.6 ± 3.6 mmHg (P=0.03 vs. ET-CO2 to PaCO2 difference during TLV; and P<0.0001 vs. TC-CO2 to PaCO2 difference during OLV). In 13 of the 15 patients, the TC-CO2 value was closer to the actual PaCO2 than the ET-CO2 value (P =0.0001). Linear regression analysis of TC-CO2 vs. PaCO2 resulted in an r2 = 0.7827 and a slope = 0.8142 ± 0.0.07965, while linear regression analysis of ET-CO2 vs. PaCO2 resulted in an r2 = 0.2989 and a slope = 0.3026 ± 0.08605.Conclusions:During OLV, TC-CO2 monitoring provides a better estimate of PaCO2 than ET-CO2 in patients undergoing VATS.

Spot Check Analysis of Gas Exchange: Invasive versus Noninvasive Methods

“…Furthermore, in line with a number of recently published studies, our data support the clinical value of P tc CO 2 monitoring, which provides an accurate tool for the continuous, non-invasive monitoring of PCO 2 [11,14,29,30]. …”

Bilateral sympathicotomy for hyperhidrosis without using single-lung ventilation

“…Video-assisted thoracoscopic surgery (VATS) is usually performed under general anesthesia with doublelumen endotracheal tube intubation (3). The undesired complications of double-lumen intubation are airway injury, decrease in oxygen saturation, increase in airway pressure, poor lung ventilation, and displacement of the tube during the operation (4).…”