Effects Of Different Endotracheal Suction Pressure On Ventilation Of Patients With Suction Effects And Mechanics

【Objective】 To explore the suitability effective and safe endotracheal suction pressure for the patients with mechanical ventilation.【Method】32adult patients with invasive mechanical ventilation and arterial blood pressure monitoring in general Intensive Care Unit(ICU) of three graded first-class comprehensive hospital were enrolled. Three times of closed system suction were performed on each patient with different endotracheal suction pressure include-75mmHg,-150mmHg and-300mmHg by nurses after training qualified, the order of suction pressure was random decided by envelope method. Suction effects that include interval time (from the end of this suction to the beginning of next time) and sputum sound (no improvement equal to1point; attenuate equal to2point; disappear equal to3point) were evaluated by two registered nurses. The kinetics of oxygen, hemodynamic, and respiratory mechanics were dynamically monitored and recorded by nurses before endotracheal suction2minutes, and after endotracheal suction5and10minutes.【Results】 Interval time after suction when pressure was set for-150mmHg was longer than-75mmHg and-300mmHg, sputum sound score after suction when pressure was set for-150mmHg and-300mmHg was better than-75mmHg (p<0.05). In terms of respiratory mechanics, PaO2、 PaCO2and PaO2/FiO2with different pressure and time point were highly correlated (p<0.01) and got a change over time trend, PaO2and PaO2/FiO2after suction5min were higher than before when pressure was set for-75mmHg(p<0.01), PaO2and PaO2/FiO2after suction5min and10min were higher than before when pressure was set for-150mmHg (p<0.01). In terms of hemodynamic, SBP, DBP and MAP with different pressure and time point were highly correlated (p<0.01) and got a change over time trend, SBP, DBP and MAP after suction5min were higher than before when pressure was set for-300mmHg (p<0.01). In terms of respiratory mechanics, Ppeak, Pplat, PEEP, Ppeak-PEEP and Cst with different pressure and time point were highly correlated (p<0.01),but does not got a change over time trend.【Conclusion】-150mmHg was the safe, effective and suitable suction pressure for patients with invasive machine ventilator. When pressure was set for-150mmHg， not only the suction effect was good, and also hemodynamic and respiratory mechains were stable.