The Clinical Rearch Of The Assessment Of Lung Recruitment And The Best PEEP In Patients With ARDS By Bedside Ultrasound

Objective:1. Verify the effects of lung recruitment in acute respiratory distress syndrome(ARDS)patients with ultrasound score.2. Explore the feasibility of assessment positive end expiratory pressure (PEEP) titrationafter lung recruitment with lung ultrasoundMethods:The first part: Sixteen patients patients with ARDS were studied. OptimalOXYgenation-detected (OXY) and lung ultrasound （LUS） were performed withPEEP increased lung treatment in lung recruitment.It was terminal point until the detection of PaO2/FiO2>or=400mmHg withoptimal OXYgenation-detected method or the same score in twice with LUS for thelung recruitment. Respiratory Mechanics, Gas Exchange, Hemodynamics and LUSscore were examined in these patients.The second part: Sixteen patients with ARDS were studied. At the terminal pointit was lasted fifteen minutes during PEEP increased lung treatment in lung recruitment,and blood gas analysis was detected and PaO2/FIO2ratio and LUS score werecalculated, until PEEP was decreased from20cmH2O, every2cmH2O to PaO2/FIO2ratio was over10%. Then the best PEEP could be obtained.Results:PartI1.Optimal OXYgenation-detected（OXY） and lung ultrasound （LUS）could beapplied to monitor the end of lung recruitment in ARDS patients, with the process of recruitment OXYgenation improved, regasification score increased.2.PEEP and the alveolar opening pressure of lung of the terminal point of lungrecruitment is significant higher in LUS group than in the optimalOXYgenation-detected group.（PEEP:15±1.9VS13±3.1，P＜0.05）OXYgen pressureof artery (PaO2) were also significant higher in lung ultrasound group than in theoptimal OXYgenation-detected group（475±56vs403±45，P<0.05）. There was nosignificant difference of systolic blood pressure (SBP), diastolic blood pressure(DBP),mean arterial pressure(MAP) and heart rate(HR) and dynamic compliance ofrespiratory system(Cdyn) between two groups. It indicated that lung recruitmentmonitored by LUS the alveolar opening pressure was much more higher and the levelof OXYgenation was improved. However there was no significant difference ofpulmonary compliance even if with higher opening lung pressure.3B-Line disappeared and area of lung consolidation turned into B-Line were themajor signs monitored by LUS，and these signs appeared on prothorax and lateralthorax however there were little changes on lower post thorax of lung consolidation.Part II1. It was terminal point, PaO2/FiO2≤10%in optimal OXYgenation-detectedgroup, with PEEP decreasing, regasification score descreased. B-Line appeared oncemore on prothorax and lateral thorax on the best PEEP monitored by optimalOXYgenation-detected.2. The process was regasification score descreased slowly with PEEP lever beingdecreased, then an jump decrease change appeared (regasification scoredecreased≥30%between two adjacent score). The level PEEP was higher than the bestone monitored by optimal OXYgenation-detected.Conclusion1. Bedside ultrasound could be a good method to evaluate the effect ofincreasing PEEP to promote lung recruitment2. Ultrasound could not be the only way to evaluate the terminal point of lungrecruitment, because it could not effectively distinguish normal ventilation orhyperventilation. 3. Bedside ultrasound technology as a new best method increasing PEEP topromote lung recruitment to ARDS patients is expected to further clinical application.