The Influence Of Lung Recruitment Maneuver To The Respiratory Function Of Patients Of Long-term Mechanical Ventilation

Objective: To investigate lung conformance, oxygen ability, shunt fraction ratio and ratio of dead space in ARDS patients using the lung protection ventilation strategies and lung recruitment maneuver (RM), to observe the clinical application.Methods: 25 ARDS patients with mechanical ventilating in ICU were selected. Arterial partial pressure of oxygen(PaO₂) and carbon dioxide(PaCO₂) , end tidal carbon dioxide pressure(P_etCO₂), compliance(Cs). heart rate(HR), mean arterial pressure(MAP) were collected before recruitment, right after recruitment ,in half hour, in an hour. Shunt fraction ratio, ratio of dead space to tidal volume were calculated. Lung recruitment maneuver was carried on once 6 hours till to 24 hours (5 times of RM) and collect the data above again 1 hour after the last RM. The data within group were analyzed by analysis of variance and the data between groups were analyzed by paired t test.Results: In patients with ARDS using mechanical ventilation, the oxygen index right after RM increased remarkably (148.1±39.4: 167.3±39.5, P<0.05). There is no significant change at an hour later of RM (148.1±39.4: 143.9±36.4, P>0.05), but it increased again at an hour later after 24 hours RM (148.1 ±39. 4: 174. 8±40. 0, P<0.05) and is higher than it at an hour after the 1^st RM (143.9±36.4: 174. 8±40. 0, P<0.05). The lung conformance right after RM increased (27.0±6.8: 30.3±7.7, P<0.05), and has no change at 30 minutes and an hour later (27.0±6. 8: 28.2±7.8, 27.0±6.8: 27.7±7.9, P>0.05), but increased significantly at an hour later after 24 hours RM higher than it at an hour after the 1^st RM(27.7±7.9: 29.9±8.0, P <0.05). The lung shunt fraction ratio right after RM decreased (23.0±3.4: 21.4±2.6, P <0.05), and have no change at an hour later (23.0±3.4: 22.7±3.9, P>0.05), but decreased at an hours later after 24 hours RM, lower than it at an hour after the 1^st RM(28.5±7.0: 22.7±3.9, P<0.05). The ratio of dead space to tidal volume right after RM decreased (28.7±8.1: 22.8 ± 7.9, P<0.01), and have no change at an hour later (28.7±8.1:27.8±7.3, P>0.05), but decreased again at an hour later after 24 hours RM to 25.8±7. 5 (P>0.05). The blood pressure and heart rate have no significant change.Conclusion: The lung protection ventilation strategies and lung recruitment maneuver (RM) could both improved lung conformance , oxygen index lung ,anddecreased the shunt fraction ratio , ratio of dead space to tidal volume .but It back worse in an hour. RMs for 24 hours could improved significantly. The RM has no influence to homodynamicPostgraduate student: Wang Xiaohong (critical care medicine) Directed by Prof. Sun Yunbo...