Clinical Observation on Effects of Endotracheal Suction on Gas Exchange and Respiratory Mechanics in Mechanically Ventilated Patients

Objective To evaluate the effects of open endotracheal suction in the mode of pressure-controlled ventilation(PCV)and volume-controlled ventilation(VCV)on gas exchange and respiratory mechanics in acute respiratory failure(ARF)patients with chronic obstructive pulmonary disease(COPD)or severe sepsis. Methods A retrospective,crossover controlled cohort study was conducted in a total of 96 patients with ARF,including 59 patients with COPD(group A)and 37 patients with severe sepsis(group B). All the patients received open endotracheal suction in the mode of either PCV or VCV. Variations on gas exchange,respiratory mechanics and hemodynamics before and after suction were measured and compared. Results During PCV,tidal volume and compliance were decreased compared with the baseline level for patients in group A at 1 min and 10 min after suction,and there was significant difference compared with group B(all P0.05). In the mode of VCV,peak airway pressure was increased and compliance was decreased compared with baseline levels for patients in group A at 1 min and 10 min after suction,and there was significant difference compared with group B(all P0.05). In the mode of PCV, PaO2 was increased compared with the baseline level for patients both in group A and group B at 3 min and 10 min after suction,however, the proportion of increase was lower than that in the VCV model(P0.05). Conclusion Open endotracheal suction can influence respiratory mechanics of acute respiratory failure patients in both PCV and VCV mode,and the changes in patients with severe sepsis is more obvious than in patients with COPD. In the VCV,the effect on gas exchange function recoveries relatively quickly.