Early reapplication of prone position during venovenous ECMO for acute respiratory distress syndrome: a prospective observational study and propensity-matched analysis.

A combination of prone positioning (PP) and venovenous extracorporeal membrane oxygenation (VV-ECMO) is safe, feasible, and associated with potentially improved survival for severe acute respiratory distress syndrome (ARDS). However, whether ARDS patients, especially non-COVID-19 patients, placed in PP before VV-ECMO should continue PP after a VV-ECMO connection is unknown. This study aimed to test the hypothesis that early use of PP during VV-ECMO could increase the proportion of patients successfully weaned from ECMO support in severe ARDS patients who received PP before ECMO. In this prospective observational study, patients with severe ARDS who were treated with VV-ECMO were divided into two groups: the prone group and the supine group, based on whether early PP was combined with VV-ECMO. The proportion of patients successfully weaned from VV-ECMO and 60-day mortality were analyzed before and after propensity score matching. A total of 165 patients were enrolled, 50 in the prone and 115 in the supine group. Thirty-two (64%) and 61 (53%) patients were successfully weaned from ECMO in the prone and the supine groups, respectively. The proportion of patients successfully weaned from VV-ECMO in the prone group tended to be higher, albeit not statistically significant. During PP, there was a significant increase in partial pressure of arterial oxygen (PaO2) without a change in ventilator or ECMO settings. Tidal impedance shifted significantly to the dorsal region, and lung ultrasound scores significantly decreased in the anterior and posterior regions. Forty-five propensity score-matched patients were included in each group. In this matched sample, the prone group had a higher proportion of patients successfully weaned from VV-ECMO (64.4% vs. 42.2%; P = 0.035) and lower 60-day mortality (37.8% vs. 60.0%; P = 0.035). Patients with severe ARDS placed in PP before VV-ECMO should continue PP after VV-ECMO support. This approach could increase the probability of successful weaning from VV-ECMO. ClinicalTrials.Gov: NCT04139733. Registered 23 October 2019.

Wang R ，Tang X ，Li X ，Li Y ，Liu Y ，Li T ，Zhao Y ，Wang L ，Li H ，Li M ，Li H ，Tong Z ，Sun B ... -  《Annals of Intensive Care》

Effect of prone position in patients with acute respiratory distress syndrome supported by venovenous extracorporeal membrane oxygenation: a retrospective cohort study.

The application of prone position (PP) in acute respiratory distress syndrome (ARDS) supported by venovenous extracorporeal membrane oxygenation (VV-ECMO) is controversial. To evaluate the safety and efficacy of application of PP during VV-ECMO in patients with ARDS. This was a single-center, retrospective study of patients who met the Berlin definition of ARDS, and were supported with VV-ECMO. We divided the patients into two groups. The prone group included patients who were supported by VV-ECMO, and experienced at least one period of PP, while those without PP during VV-ECMO were defined as the supine group. Propensity score matching (PSM) at a ratio of 1:1 was introduced to minimize potential confounders. The primary outcomes were the complications of PP and the change of arterial oxygen pressure/fraction of the inspiration (PaO2/FiO2) ratio after PP. The secondary outcomes were hospital survival, ICU survival, and ECMO weaning rate. From April 2013 to October 2020, a total of 91 patients met the diagnostic criteria of ARDS who were supported with ECMO. 38 patients (41.8%) received at least one period of PP during ECMO, while 53 patients (58.2%) were maintained in supine position during ECMO. 22 minor complications were reported in the prone group and major complications were not found. The other ECMO-related complications were similar between two groups. The PaO2/FiO2 ratio significantly improved after PP compared with before (174.50 (132.40-228.25) mmHg vs. 158.00 (122.93-210.33) mmHg, p < 0.001). PSM selected 25 pairs of patients with similar characteristics. Hospital survival or ICU survival did not differ between the two groups (40% vs. 28%, p = 0.370; 40% vs. 32%, p = 0.556). Significant difference of ECMO weaning rate between two groups was not found (56% vs. 32%, p = 0.087). PP during VV-ECMO was safe and could improve oxygenation. A large-scale and well-designed RCT is needed in the future.

Chen Z ，Li M ，Gu S ，Huang X ，Xia J ，Ye Q ，Zheng J ，Zhan Q ，Wang C ... -  《BMC Pulmonary Medicine》

Prone positioning in severe ARDS requiring extracorporeal membrane oxygenation.

Rilinger J ，Zotzmann V ，Bemtgen X ，Schumacher C ，Biever PM ，Duerschmied D ，Kaier K ，Stachon P ，von Zur Mühlen C ，Zehender M ，Bode C ，Staudacher DL ，Wengenmayer T ... -  《CRITICAL CARE》

Prone positioning during venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review and meta-analysis.

Prone positioning (PP) improves oxygenation and respiratory mechanics and is associated with lower mortality in patients with moderate to severe acute respiratory distress syndrome (ARDS). Despite this, some patients develop refractory hypoxemia and hypercapnia requiring venovenous extracorporeal membrane oxygenation (VV ECMO) support and are usually cared for in supine position. The physiologic and outcome benefits of routine PP of patients during VV ECMO remains unclear. Hence, we conducted the systematic review and meta-analysis to evaluate the outcome benefits of PP for patients with ARDS being treated with VV ECMO. After registration with PROSPERO (CRD42020199723), MEDLINE, EMBASE, Scopus and Cochrane databases were searched for relevant studies that reported PP in more than 10 adult patients supported with VV ECMO from origin to 1 March 2021. Studies were reviewed for quality using appropriate Joanna Briggs Institute (JBI) checklists, and certainty of evidence was assessed using the GRADE approach. The random-effects model (DerSimonian and Laird) was used. The primary outcome of interest was cumulative survival. Secondary outcomes were intensive care unit length of stay (ICU LOS) and ECMO duration. Changes in arterial blood gas (ABG) values, ventilator mechanics and complication rates were also studied. Of 812 potentially relevant publications, 12 studies (640 patients) met our inclusion criteria. Due to overlapping study populations, 11 studies were included in the final meta-analysis. Cumulative survival in patients that underwent PP was 57% (95% CI 41.9-71.4, high certainty). Patients that underwent PP had longer ICU LOS (+ 14.5 days, 95% CI 3.4-25.7, p = 0.01) and ECMO duration (+ 9.6 days, 95% CI 5.5-13.7, p < 0.0001). After PP, patients had significantly higher PaO2/FiO2 ratio, lower PaCO2 and reduced ventilator driving pressure, and no major complications were reported. PP during VV ECMO appears safe with a cumulative survival of 57% and may result in longer ECMO runs and ICU LOS. However, evidence from appropriately designed randomized trials is needed prior to widespread adoption of PP on VV ECMO.

Poon WH ，Ramanathan K ，Ling RR ，Yang IX ，Tan CS ，Schmidt M ，Shekar K ... -  《CRITICAL CARE》

Effect of prone positioning on survival in adult patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a prospective multicenter randomized controlled study.

Current data supporting the use of prone positioning (PP) during venovenous extracorporeal membrane oxygenation (VV-ECMO) in patients with acute respiratory distress syndrome (ARDS) are limited. This prospective randomized controlled study aimed to determine whether PP implemented within 24 hours of ECMO can improve survival in these patients. From June 2021 to July 2023, 97 adult patients receiving VV-ECMO for ARDS in three centers were enrolled and 1:1 randomized into PP (n=49) and control groups (n=48). Patients in the PP group receiving prone positioning, while the control group were maintained in the supine position. The primary outcome was 30-day survival, and secondary outcomes included in-hospital survival and other clinical outcomes. All 97 patients were included for analysis. Patient characteristics did not significantly differ between the two groups. The median duration of PP was 81 hours, and the median number of PP sessions was 5 times. PP improved oxygenation and ventilator parameters. The incidence of complications during PP was low, with pressure sores being the most frequent (10.2%). The 30-day survival was significantly higher in the PP group (67.3% vs. 45.8%; P=0.033), as was in-hospital survival (61.2% vs. 39.6%; P=0.033). In the PP group, the successful ECMO weaning rate was significantly higher (77.5% vs. 50.0%; P=0.005), and the duration of ECMO support was significantly shorter {10 [8-11] vs. 10 [8-14] days; P=0.038}. However, in subgroup analysis of COVID patients the 30-day survival, in-hospital survival, successful ECMO weaning rate and the duration of ECMO support did not differ between the groups. The duration of mechanical ventilation, length of intensive care unit stay, and length of hospital stay did not significantly differ between the groups. When initiated within 24 hours of ECMO, PP can improve 30-day survival in patients with ARDS receiving VV-ECMO. In addition, it may improve the successful ECMO weaning rate and reduce the duration of ECMO support. However, considering the limitations, more strictly designed, large sample prospective randomized controlled trials are proposed. Chinese Clinical Trial Registry ChiCTR2300075326.

Tong H ，Pan F ，Zhang X ，Jia S ，Vashisht R ，Chen K ，Wang Q ... -  《-》