A tracheal stenosis is caused by mucosal ischemic injury related to a high cuff pressure (P_cuff) 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 P_cuff. To prevent these complications, the P_cuff should be kept appropriately because the appropriate P_cuff appears to change according to the patients' bedside. To address the necessity of continuous P_cuff monitoring, the change in the P_cuff was evaluated at various V_cuff levels on a daily basis in patients with long-term mechanical ventilation. The utility of mercury column sphygmomanometer for the continous monitoring P_cuff was also investigated.

The change in P_cuff according to the increase in V_cuff was observed in 17 patients with prolonged endotracheal intubation for mechanical ventilation for 2 week or more. This maneuver measured the change in P_cuff daily during the mechanical ventilation days. In addition, the P_cuff measured by mercury column sphygmomanometer was compared with the P_cuff measured by an automatic cuff pressure manager.

There were no statistically significant changes of P_cuff during more than 14 days of intubation for mechanical ventilation. However the V_cuff required to maintain the appropriate P_cuff varied from 1.9cc to 9.6cc. In addition, the intra-individed variation of the P_cuff was observed from 10cmH₂O to 46cmH₂O at constant 3cc V_cuff. The P_cuff measured by the bedside mercury column sphymomanometer is well coincident with that measured by the automatic cuff pressure manager.

Continuous monitoring and management of the P_cuff to maintain the appropriate P_cuff 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.