بررسی تاثیر تغییر وضعیت بدن بر فشار کاف لوله تراشه در بیماران تحت تهویه مکانیکی

Background: Endotracheal tube cuff pressure must be maintained in safe range. Many factors could be affecting on endotracheal tube cuff pressure in patients on mechanical ventilation. Patients undergoing mechanical ventilation (MV) in critical care settings require changing position for different reasons. The aim of this study was to determine the effect of changes in body position and head of bed on the endotracheal tube cuff pressure in patients with mechanical ventilation. Methods: This quasi-experimental study (pre-post design) was performed from April to October 2016 on 70 patients with positive pressure mechanical ventilation in critical care settings in two university hospitals in the cities of Semnan and Shahroud, Semnan Province, Iran. At first, the endotracheal tube cuff pressure of patients was regulated on 25 cmH2O in the bed position of 30 degree. Then the patients were randomly positioned on zero degree bed position, 45 degree bed position, lateral position of patients toward mechanical ventilation apparatus and lateral position opposite the MV apparatus. In each position cuff pressure was measured after 5 minutes pause and head and neck of the patients was not flexed or extended. Tube cuff pressure was measured and recorded in the end expiratory with aneroid manometer after each position change. Data analysis was performed with software of SPSS software, version 18 (Armonk, NY, USA) in the significant level of 0.05. Results: Most of study patients (58.6%) were male and no smokers (81.4%). Age mean of patients were 63.37±20.9 years. Most of patients connected to MV because of respiratory failure. In each change positions and head of bed regulation, the mean of endotracheal tube cuff pressures were significantly increased (P<0.001). Endotracheal tube cuff pressure in the lateral position opposite to the apparatus had maximum increase (29.12±0.41 cmH2O) and in the zero degree bed position tube cuff pressure had minimum increase (27.6±0.38 cmH2O). Conclusion: Findings of this study showed that changing position of bed and patients undergoing mechanical ventilation, especially in lateral position opposite to the apparatus could increase endotracheal tube cuff pressure. This increase may reach to abnormal range and cause tracheal injury.