The PRESERVE mortality risk score and analysis of long-term outcomes after extracorporeal membrane oxygenation for severe acute respiratory distress syndrome

Abstract

Purpose: This study was designed to identify factors associated with death by 6 months post-intensive care unit (ICU) discharge and to develop a practical mortality risk score for extracorporeal membrane oxygenation (ECMO)-treated acute respiratory distress syndrome (ARDS) patients. We also assessed long-term survivors' health-related quality of life (HRQL), respiratory symptoms, and anxiety, depression and post-traumatic stress disorder (PTSD) frequencies.

Methods: Data from 140 ECMO-treated ARDS patients admitted to three French ICUs (2008-2012) were analyzed. ICU survivors contacted >6 months post-ICU discharge were assessed for HRQL, psychological and PTSD status.

Results: Main ARDS etiologies were bacterial (45%), influenza A[H₁N₁] (26%) and post-operative (17%) pneumonias. Six months post-ICU discharge, 84 (60%) patients were still alive. Based on multivariable logistic regression analysis, the PRESERVE (PRedicting dEath for SEvere ARDS on VV-ECMO) score (0-14 points) was constructed with eight pre-ECMO parameters, i.e. age, body mass index, immunocompromised status, prone positioning, days of mechanical ventilation, sepsis-related organ failure assessment, plateau pressure andpositive end-expiratory pressure. Six-month post-ECMO initiation cumulative probabilities of survival were 97, 79, 54 and 16% for PRESERVE classes 0-2, 3-4, 5-6 and ≥7 (p < 0.001), respectively. HRQL evaluation in 80% of the 6-month survivors revealed satisfactory mental health but persistent physical and emotional-related difficulties, with anxiety, depression or PTSD symptoms reported, by 34, 25 or 16%, respectively.

Conclusions: The PRESERVE score might help ICU physicians select appropriate candidates for ECMO among severe ARDS patients. Future studies should also focus on physical and psychosocial rehabilitation that could lead to improved HRQL in this population.

Trial registration: ClinicalTrials.gov NCT01470703.

Fig. 1

Study flowchart. Durations are median (interquartile range). ARDS acute respiratory disease syndrome, ECMO extracorporeal membrane oxygenation, HRQL health-related quality of life, ICU intensive care unit

Fig. 2

Kaplan–Meier estimates of cumulative probabilities of survival for patients with pre-ECMO PRESERVE score classes 0–3 (n = 34), 4–6 (n = 38), 7–9 (n = 31) and 10–15 (n = 32). The p-value was calculated by means of the log-rank test. ECMO extracorporeal membrane oxygenation, PRESERVE PRedicting dEath for SEvere ARDS on VV-ECMO

Fig. 3

Comparison of median SF-36 scores of 67 of our ARDS survivors treated by ECMO after a median follow-up of 17 months after intensive care unit discharge and their 67 age- and sex-matched control subjects [27], and 80 conventionally treated ARDS survivors at 1-year of follow-up [4], 57 ECMO-arm ARDS patients included in the conventional ventilation or ECMO for severe adult respiratory failure (CESAR) trial [9], 15 ECMO-treated Australian patients with refractory hypoxemia [19] and a pooled estimated score of five follow-up studies on ARDS survivors [33]. Higher scores denote better health-related quality of life. ARDS acute respiratory distress syndrome, BP body pain, ECMO extracorporeal membrane oxygenation, GH general health, MH mental health, PF physical functioning, RE role-emotional, RP role-physical, SF social functioning, SF-36 Short Form-36, VT vitality

Fig. 4

a Mean percentages of our ARDS survivors treated by ECMO (evaluated after a median follow-up of 17 months after ICU discharge) with clinically significant anxiety and/or depression (HAD-A/D subscale scores ≥8/21) compared with those of 156 conventionally treated ARDS patients [35], 26 myocarditis survivors treated by MCA [25], 153 trauma patients [36] and 194 ICU survivors [37]. b Mean percentages of our ECMO-treated ARDS survivors at risk of post-traumatic stress disorder compared with those of 80 conventionally treated ARDS patients [38], 26 myocarditis survivors [25] and 194 ICU survivors [37]. ARDS acute respiratory distress syndrome, ECMO extracorporeal membrane oxygenation, HAD Hospital Anxiety and Depression, ICU intensive care unit, MCA mechanical circulatory assistance