Effect Of Endotracheal Suctioning On Acute Respiratory Distress Syndrome: An Experimental And Clinical Study

Objective: The aim of our study is to find the better ways of endotrachealsuctioning and caring in the ARDS mechanical ventilated patients throughanimal and clinical work.Methods:Part 1 Animal study:Tracheal intubated mongrel dogs were injured by injecting oleic acid to buildup ARDS models. Each dog was suctioned with opened endotrachealsuctioning(OS) and closed endotracheal suctioning(CS) in randomized order.The data of arterial blood gas and mixed venous blood gas were obtained at2min before suction and at 0.5, 5 and 10min after suction, and indexes ofhemocfynamics and respiratory mechanics were attached.Part 2 Clinical study:14 ARDS ventilated patients in SICU were enrolled. Both OS and CS suctiontechniques were performed on each patient in randomized order. Arterialblood gas index was obtained at 2min before suction and at 0.5,5 and 10minafter suction. The data of inspiratory peak pressure (Ppeak), inspiratoryplateau pressure (Pplat), heart rate (HR), mean arterial pressure (MAP),oxygen saturation by pulse oximetry (SpO2), positive end expiratory pressure(PEEP), and tidal volume (VT) were recorded during performing suctiontechniques in ARDS patients.Results:Part 1 Animal study:(1)Gas exchange. After performing OS technique, there showed obviousdecreasing in the data of arterial oxygen partial pressure (PaO2), arterialoxygenation (SaO2) and arterial oxygenation partial pressure/ fractionalinspired oxygen (PaO2/ FiO2), and the data of alveolar-arterial oxygen partialpressure difference [P(A-a)DO2]] got worsen (PO.05). There were notsignificant differences in the indexes of PaQ and SaO2 between before CSand after CS(PX).05).(2)Respiratory Mechanics, There were significant increasing in the data ofPpeak, Pplat and mean airway pressure (Pmean) after suction compared tobefore suction in two suction ways (PO.05). On the contrary, the data ofpulmonary static compliance (Cs) and pulmonary dynamic compliance (CD)got worsen after OS compared to before OS (PO.05).(3)Hemodynamics. In the two suction ways, the data of mean pulmonaryarterial pressure (MPAP) significantly raised after suction (PO.05), but onlymean arterial pressure (MAP) raised after performing OS (PO.05).Part 2 Clinical study(1)Gas exchange and Metabolism. There showed significant decreases in thedata of PaO2, SaO2 and SpO2 after OS (PO.05). There were not statisticaldifferences between after CS and before CS.(2)Respiratory Mechanics. In the two suction ways, there were not significantdifferences in Ppeak, Pplat, CD and Cs between after and before suction.(3)HR and Blood Pressure. Significant increases were found in HR, systolicblood pressure (SBP) and MAP after OS and CS(PO.05).Conclusions: In our experimental and clinical work, we found that theharmful effect of OS is causing deteriorated hypoxemia. Compared to OStechnique, CS technique showed favorable effects in maintaining PEEP effectand confirming continuous ventilation during performing suction ways, and itdid not cause obviously worsen in FiO2, PaO2 and SaO2(P>0.05) duringperforming CS techniques. This is very important for ARDS patients on preventing alveolar recruitment and maintaining lung volume derecruitment In our study, we also found that both OS and CS had obvious influencing on hemodynarnics and airway pressure, and it remind us that we should pay more attention to the potential damages that caused by suction ways and we should intensify monitoring the changes of airway pressure, HR and arterial pressure during performing endotracheal suction ways in clinical nursing practice. In conclusion, compared to OS, we think that CS technique is comparatively safer and more comfortable for ARDS patients.