Correlation between microstream PETCO2 and PaCO2 in patients with general anesthesia after tracheal catheter removal

Abstract

Objective To evaluate the correlation between microstream partial pressure of end-tidal carbon dioxide (PETCO2) and arterial partial pressure of carbon dioxide (PaCO2) in patients with general anesthesia after tracheal catheter removal. Methods A total of 120 patients in Jiangsu Cancer Hospital undergoing abdominal operation under general anesthesia were selected and randomly divided into 3 groups, with 40 patients in each group. Each group received oxygen through nasal catheter at different flow rates: group L (2 L/min), group M (4 L/min) and group H (6 L/min). After 30 min of tracheal catheter removal, the value of PETCO2 was recorded and arterial blood was drawn to measure PaCO2, and the correlation between PETCO2 and PaCO2 was analyzed by Pearson. Results At 30 min of extubation, the differences in PETCO2, PaCO2, and RR among the three groups were not statistically significant (P>0.05); PaO2 and SpO2 in group L were significantly lower than those in groups M and H (P<0.05). There was a high correlation between microstream PETCO2 and PaCO2 in group L, M and H (r =0.931, 0.878 and 0.838, P＜0.01), and the correlation coefficients decreased with the increase of oxygen flow. Conclusion When microstream PETCO2 is used to monitor patients under general anesthesia in PACU after tracheal catheter removal, there is a high correlation between PETCO2 and PaCO2 at 2-6 L/min oxygen flow, which can be used as an important reference for the evaluation of PaCO2.

Keywords

• capnography， oxygen inhalation therapy， pulmonary ventilation， partial pressure of end-tidal carbon dioxide， arterial partial pressure of carbon dioxide