[Predictive values of different critical scoring systems for mortality in patients with severe acute respiratory failure supported by extracorporeal membrane oxygenation].
OBJECTIVE
To investigate the predictive values of different critical scoring systems for mortality in patients with severe acute respiratory failure (ARF) supported by venovenous extracorporeal membrane oxygenation (VV-ECMO).


METHODS
Forty-two patients with severe ARF supported by VV-ECMO were enrolled from November 2009 to July 2015.There were 25 males and 17 females. The mean age was (44±18) years (rang 18-69 years). Acute Physiology and Chronic Health Evaluation (APACHE) Ⅱ, Ⅲ, Ⅳ, Simplified Acute Physiology Score Ⅱ (SAPS) Ⅱ, Sequential Organ Failure Assessment (SOFA), ECMO net, PRedicting dEath for SEvere ARDS on VVECMO (PRESERVE), and Respiratory ECMO Survival Prediction (RESP) scores were collected within 6 hours before VV-ECMO support. The patients were divided into the survivors group (n=17) and the nonsurvivors group (n=25) by survival at 180 d after receiving VV-ECMO. The patient clinical characteristics and aforementioned scoring systems were compared between groups. Scoring systems for predicting prognosis were assessed using the area under the receiver-operating characteristic (ROC) curve. The Kaplan-Meier method was used to draw the surviving curve, and the survival of the patients was analyzed by the Log-rank test. The risk factors were assessed for prognosis by multiple logistic regression analysis.


RESULTS
(1) Positive end expiratory pressure (PEEP) 6 hours prior to VV-ECMO support in the survivors group [(9.7±5.0)cmH2O, (1 cmH2O=0.098 kPa)] was lower than that in the nonsurvivors group [(13.2±5.4)cmH2O, t=-2.134, P=0.039]. VV-ECMO combination with continuous renal replacement therapy(CRRT) in the nonsurvivors group (32%) was used more than in the survivors group (6%, χ(2)=4.100, P=0.043). Duration of VV-ECMO support in the nonsurvivors group [(15±13) d] was longer than that in the survivors group [(12±11)d, t=-2.123, P=0.041]. APACHE Ⅱ, APACHE Ⅲ, APACHE Ⅳ, ECMO net, PRESERVE, and RESP scores in the survivors group were superior to the nonsurvivors group (all P<0.05). (2) The areas under the ROC curve of APACHE Ⅳ score for predicting death were largest (0.792±0.076, 95%CI: 0.643-0.940, P<0.05). The best cutoff point was 48 for APACHE Ⅳ score with a sensitivity of 92.0%, specificity of 64.7%, and overall accuracy of 81%. (3) Kaplan-Meier survival analysis showed that 180 d survival rate of the low APACHE Ⅳ score group was higher than the high APACHE Ⅳ score group (χ(2)=11.331, P<0.05). (4) Multiple logistic regression analysis showed that PEEP (OR=1.555, 95%CI: 1.097-2.204, P<0.05), APACHE Ⅳ score (OR=1.152, 95%CI: 1.021-1.301, P<0.05), and PRESERVE score (OR=4.984, 95%CI: 1.531-16.227, P<0.05) were independent risk factors associated with mortality of patients supported by VV-ECMO.


CONCLUSIONS
The critical scoring systems proved to have good prognostic ability in predicting hospital mortality for severe ARF patients supported by VV-ECMO. Compared to other scoring systems, APACHE Ⅳ score system predicted more accurately, while specific scoring systems in predicting hospital mortality showed no advantage.
Department of Respiratory and Critical Care Medicine, Beijing Chaoyang Hospital, Capital Medical University, Beijing Institute of Respiratory Medicine, Beijing Key Laboratory of Respiratory and Pulmonary Circulation, Beijing Engineering Research Center for Diagnosis and Treatment of Respiratory and Critical Care Medicine (Beijing Chaoyang Hospital), Beijing 100020, China.
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Wang
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Sun
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Li
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He
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Tang
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Zhan
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Tong
D000328:Adult; D002681:China / Q000453:epidemiology; D015199:Extracorporeal Membrane Oxygenation / Q000401:mortality*; D005260:Female; D017052:Hospital Mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D012128:Respiratory Distress Syndrome / Q000401:mortality* / Q000628:therapy*; D012131:Respiratory Insufficiency; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D015996:Survival Rate