• J S Lee, S B Nam, C H Chang, D W Han, Y W Lee, and C S Shin.
• Department of Anesthesiology and Pain Medicine and Anesthesia and Pain Research Institute, Yonsei University College of Medicine, Seoul, Korea.
• Acta Anaesthesiol Scand. 2005 Jul 1;49(6):759-62.

BackgroundThe Laryngeal Tube (LT), (VBM Medizintechnik, Sulz, Germany) is a relatively new supraglottic device for controlling the airway. Arterial carbon dioxide tension (PaCO(2)) can be estimated by monitoring the end-tidal tension of carbon dioxide (PETCO(2)). The relationship between PETCO(2) and PaCO(2) during controlled ventilation via the LT has not been reported.MethodsDuring general anesthesia, 45 patients were mechanically ventilated using an LT. PETCO(2) and PaCO(2) were measured once PETCO(2) had reached a steady state. The LT was then removed and the trachea intubated using an endotracheal tube (ETT), and the identical ventilatory variables were resumed. Following stabilization, PETCO(2) was again determined and PaCO(2) estimated.ResultsThe mean PETCO(2) and PaCO(2) values were 4.43 +/- 0.26 kPa and 4.67 +/- 0.32 kPa, respectively, during LT ventilation, and 4.36 +/- 0.23 kPa and 4.61 +/- 0.26 kPa, respectively, during ETT ventilation. Analysis of differences between the PETCO(2) and PaCO(2) values using the Bland and Altman method revealed a bias +/- precision of 0.24 +/- 0.15 kPa for LT and 0.27 +/- 0.15 kPa for ETT. The root mean square error was 0.28 for the LT and 0.30 for the ETT.ConclusionThis study suggests that for healthy adult patients mechanically ventilated via the LT, the PETCO(2) value reflects the PaCO(2) value as closely as when patients are ETT ventilated, allowing capnometry to be used to evaluate the adequacy of ventilation.

19 keywords...

hide…