BACKGROUND: A tracheal stenosis is caused by mucosal ischemic injury related to a high cuff pressure (Pcuff) of the endotracheal tube. In contrast, aspiration of the upper airway secretion and impaired g as exchange due to cuff leakage is related to a low Pcuff. To prevent these complications, the Pcuff should be kept appropriately because the appropriate Pcuff appears to change according to the patients' bedside. To address the necessity of continuous Pcuff monitoring, the change in the Pcuff was evaluated at various Vcuff levels on a daily basis in patients with long-term mechanical ventilation. The utility of mercury column sphygmomanometer for the continous monitoring Pcuff was also investigated. METHOD: The change in Pcuff according to the increase in Vcuff was observed in 17 patients with prolonged endotracheal intubation for mechanical ventilation for 2 week or more. This maneuver measured the change in Pcuff daily during the mechanical ventilation days. In addition, the Pcuff measured by mercury column sphygmomanometer was compared with the Pcuff measured by an automatic cuff pressure manager. RESULTS: There were no statistically significant changes of Pcuff during more than 14 days of intubation for mechanical ventilation. However the Vcuff required to maintain the appropriate Pcuff varied from 1.9cc to 9.6cc. In addition, the intra-individed variation of the Pcuff was observed from 10cmH2O to 46cmH2O at constant 3cc Vcuff. The Pcuff measured by the bedside mercury column sphymomanometer is well coincident with that measured by the automatic cuff pressure manager. CONCLUSION: Continuous monitoring and management of the Pcuff to maintain the appropriate Pcuff level in order to prevent cuff related problems during long-term mechanical ventilation is recommended. For this purpose, mercury column sphygmomanometer may replace the specific cuff pressure monitoring equipment.