Evaluation And Prognostic Value Of Pulmonary Ultrasound Score Combined With SpO₂/FiO₂ In Prone Ventilation Of ARDS Patients

Objective:To investigate whether Lung Ultrasound Score（LUS）combined with Sp O₂/Fi O₂ can predict the effect of prone ventilation in ARDS patients.Methods:In this prospective study,60 patients with moderate-to-severe ARDS admitted to the Department of Critical Care,Yijishan Hospital,Wannan Medical College from March 2021 to December 2022 were included.Lung ultrasound was used to evaluate the patients’lungs at 0,1 and 3 hours after the first day prone position,and the results were recorded as LUS₀,LUS₁ and LUS₃.The ultrasound image data were evaluated blind by two clinicians,The scoring criteria for lung injury in lung ultrasound were as follows:1.Normal ventilation score 0（line A or no more than two lines B）;.2.Moderate tissue degasification score:1（there are three or more well-spaced B lines）;3.Severe tissue degasification score:2（multiple combined B lines）;4.The evaluation of pleural effusion or lung consolidation was 3 points.The total score of both lungs ranged from 0 to 36 points,and the higher the score,the more severe the lung injury.The general clinical status of ARDS patients after admission was recorded,including the severity of the patient’s condition（APACHE II score）and the primary cause of respiratory failure.At the same time,blood gas analysis indexes,percutaneous oxygen saturation and inhalation oxygen concentration were recorded at 0,1and 3h after the prone position.The changes of lung ultrasound scores 0-1h were recorded asΔLUS_0-1,0-3h asΔLUS_0-3,Patients were divided into prone ventilation positive group（n=31）（P/F ratio>300mm Hg）and prone ventilation negative group（n=29）（P/F ratio<300mm Hg）according to the ratio of arterial oxygen partial pressure to inhaled oxygen partial pressure on day 7（P/F ratio）.The 28-day survival was followed up and recorded.The patients were divided into survival group（n=33）and death group（n=27）according to the 28-day mortality rate.Clinical data and ultrasound imaging data of patients were statistically analyzed.Paired sample T test was used to compare the data at different time points,and two independent sample T test was used for comparison between groups according to the grouping situation.Binary Logistic regression was used to analyze the predictive value of LUS combined with Sp O₂/Fi O₂.For LUS,Sp O₂/Fi O₂ and combined predictive values,the area under the receiver operating characteristic curve(AUC_ROC)was measured to evaluate the predictive effect of LUS and Sp O₂/Fi O₂ on prone ventilation in ARDS patients and the value of prognostic evaluation.Results:There were no significant differences in gender,age,vital signs,etiology,underlying diseases and APACHEⅡscores between negative and positive groups,survival and death groups（P>0.05）.LUS₀,LUS₁ and LUS₃ were respectively（22.35±6.47,18.47±6.94 and 14.07±6.81）,and the pinion-to-pair difference was statistically significant（P<0.05）.The values ofΔLUS_0-1 andΔLUS_0-3 in prone ventilation positive group were（4.55±1.77 and 9.45±2.26）,respectively,which were higher than those in prone ventilation negative group（3.17±1.61 and 7.03±2.50）（P<0.05）.If theΔLUS_0-1 value was used to predict the area under the curve of ARDS patients with oxygenation greater than 300mm Hg after 7 days,the sensitivity and specificity were 71%and 69%（95%CI 0.604-0.860）whenΔLUS_0-1 value was greater than or equal to 3.5.IfΔLUS_0-3 predicted the area under the curve of ARDS patients with oxygenation greater than 300 mm Hg after 7 days was 0.764,the sensitivity and specificity were 71%and 75.9%（95%CI 0.641--0.886）whenΔLUS0-3 was greater than or equal to 8.5.TheΔLUS_0-1 andΔLUS_0-3 values in prone ventilation survival group were（5.55±1.82 and 9.45±2.39）points,respectively,which were higher than those in prone ventilation death group（3.07±1.47 and 6.81±2.22）points（P<0.05）.ΔLUS_0-1 predicted the area under the curve of 28-day death of ARDS patients was 0.738,and the sensitivity and specificity were 69.7%and 71.4%（95%CI 0.612-0.884）whenΔLUS_0-1was greater than or equal to 3.5.The area under the curve ofΔLUS_0-3 predicted the 28-day mortality of ARDS patients was 0.783,and the sensitivity and specificity were 69.7%and 77.8%（95%CI 0.669--0.898）whenΔLUS_0-3 was greater than or equal to 8.5.LUS₁ combined with S/F₁ predicted that the area under ROC curve of oxygenation over 300mm Hg after 7 days was 0.850,the sensitivity was 90.3%,and the specificity was 75.9.LUS₃ combined with S/F₃ predicted that the area under ROC curve of oxygenation greater than 300mm Hg after 7 days was 0.957,the sensitivity was 90.3%,and the specificity was 86.2%.The area under ROC curve of LUS₁combined with S/F₁to predict the 28-day mortality of ARDS patients in prone ventilation was0.882,the sensitivity was 84.8%,and the specificity was 74.1%.The area under ROC curve of LUS₃ combined with S/F₃to predict the 28-day mortality of ARDS patients with prone ventilation was 0.949,the sensitivity was 87.9%,and the specificity was 88.9%.Conclusion:Pulmonary ultrasound score combined with Sp O₂/Fi O₂ has certain reference value in predicting the oxygenation effect after 7 days and the survival rate at 28days in prone ventilation patients with ARDS patients.