Influence of temperature on tracheal tube cuff pressure during cardiac surgery

Background: Lateral wall pressure may cause tracheal injury by affecting tracheal capillary blood flow. Damage to the trachea is less severe when lateral wall pressure exerted by the endotracheal tube cuff does not exceed the mean capillary perfusion pressure of the mucosa. The purpose of this study was to determine the effects of hypothermic and normothermic cardiopulmonary bypass (CPB) on tracheal tube cuff pressure dynamics. Methods: Twenty‐two patients were studied during normothermic CPB (pulmonary artery blood temperature in the CPB period between 36 and 35°C), and 22 patients during hypothermic CPB (pulmonary artery temperature in the CPB period between 32 and 28°C). A Mallinckrodt Medical Lo‐ContourTM Murphy tracheal tube, with high‐volume, low‐pressure cuff was used without lubricant. Intracuff pressure (ITCP) was recorded at end‐expiration before, during and after cardiopulmonary bypass. Results: ITCP measurements were different between groups during CPB at aortic cross‐clamping (13.9±0.8 mmHg in the normothermic group versus 11.3±0.4 mmHg in the hypothermic group, P