Prone position during ECMO is safe and improves oxygenation

Comparison of venovenous extracorporeal membrane oxygenation, prone position and supine mechanical ventilation for severely hypoxemic acute respiratory distress syndrome: a network meta-analysis

PURPOSE

Severe acute respiratory distress syndrome (ARDS) with PaO2/FiO2 < 80 mmHg is a life-threatening condition. The optimal management strategy is unclear. The aim of this meta-analysis was to compare the effects of low tidal volumes (Vt), moderate Vt, prone ventilation, and venovenous extracorporeal membrane oxygenation (VV-ECMO) on mortality in severe ARDS.

METHODS

We performed a frequentist network meta-analysis of randomised controlled trials (RCTs) with participants who had severe ARDS and met eligibility criteria for VV-ECMO or had PaO2/FiO2 < 80 mmHg. We applied the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) methodology to discern the relative effect of interventions on mortality and the certainty of the evidence.

RESULTS

Ten RCTs including 812 participants with severe ARDS were eligible. VV-ECMO reduces mortality compared to low Vt (risk ratio [RR] 0.77, 95% confidence interval [CI] 0.59-0.99, moderate certainty) and compared to moderate Vt (RR 0.75, 95% CI 0.57-0.98, low certainty). Prone ventilation reduces mortality compared to moderate Vt (RR 0.78, 95% CI 0.66-0.93, high certainty) and compared to low Vt (RR 0.81, 95% CI 0.63-1.02, moderate certainty). We found no difference in the network comparison of VV-ECMO compared to prone ventilation (RR 0.95, 95% CI 0.72-1.26), but inferences were based solely on indirect comparisons with very low certainty due to very wide confidence intervals.

CONCLUSIONS

In adults with ARDS and severe hypoxia, both VV-ECMO (low to moderate certainty evidence) and prone ventilation (moderate to high certainty evidence) improve mortality relative to low and moderate Vt strategies. The impact of VV-ECMO versus prone ventilation remains uncertain.

The use of prone position ventilation in Danish patients with COVID-19-induced severe acute respiratory distress syndrome treated with veno-venous extracorporeal membrane oxygenation: A nationwide cohort study with focus on pulmonary effects

BACKGROUND

Prone position ventilation (PPV) is recommended for patients with COVID-19 induced severe Adult Respiratory Distress Syndrome (ARDS) and is used for patients supported with V-V ECMO as well. The purpose of this study was to describe the use of PPV in these patients focusing on physiological effects with the hypothesis that PPV could reduce oxygen need and improve dynamic compliance.

METHODS

This study was a nationwide retrospective analysis of all COVID-19 patients in Denmark from March 2020 - December 2021 with severe ARDS and need of V-V ECMO support. Data on the number of patients treated with PPV, number of PPV sessions, timing, the time spent in prone position, pulmonary physiological response types with analysis of variables affecting the response are reported.

RESULTS

Out of 68 patients 44 were treated with 220 PPV sessions and a positive clinical response was observed in 80% of patients but only in 45% of sessions. On a single session level, increased compliance was observed in 38% and increased oxygenation in only 15% of 220 sessions, with within-patient heterogeneity. Higher dynamic compliance at the beginning of a PPV session was associated with a lower delta change in dynamic compliance during PPV. The response to a PPV session could not be predicted by the response in the prior session. Dynamic compliance did not change during the ECMO course.

CONCLUSION

Eighty percent of patients responded positively during a PPV session, but this was not associated with overall pulmonary improvement. On a single patient level, responses were heterogenous and only 45% of sessions resulted in clinical improvement. Response in dynamic compliance was associated with starting values of compliance.

The occurrence of pressure injuries and related risk factors in patients undergoing extracorporeal membrane oxygenation for respiratory failure: A retrospective single centre study

INTRODUCTION

Limited data is available regarding the incidence of pressure injuries in patients who have undergone Extracorporeal Membrane Oxygenation (ECMO), a life-saving technique that provides respiratory support for hypoxemia that does not respond to conventional treatment.

AIM

To assess the incidence of pressure injuries and identify the risk factors in Acute Respiratory Distress Syndrome patients receiving ECMO.

METHODS

A retrospective observational study utilizing prospectively collected data was performed in an Italian intensive care unit, between 1 January 2012 and 30 April 2022 enrolling all consecutive patients with Acute Respiratory Distress Syndrome who underwent ECMO.

RESULTS

One hundred patients were included in this study. 67 patients (67%) developed pressure injuries during their intensive care unit stay, with a median of 2 (1-3) sites affected. The subgroup of patients with pressure injuries was more hypoxic before ECMO implementation, received more frequent continuous renal replacement therapy and prone positioning, and showed prolonged ECMO duration, intensive care unit and hospital length of stay compared to patients without pressure injuries. The logistic model demonstrated an independent association between the pO2/FiO2 ratio prior to ECMO initiation, the utilization of the prone positioning during ECMO, and the occurrence of pressure injuries.

CONCLUSIONS

The incidence of pressure injuries was elevated in patients with Adult Respiratory Distress Syndrome who received ECMO. The development of pressure injuries was found to be independently associated with hypoxemia before ECMO initiation and the utilization of prone positioning during ECMO.

IMPLICATIONS FOR CLINICAL PRACTICE

Patients who require ECMO for respiratory failure are at a high risk of developing pressure injuries. To ensure optimal outcomes during ECMO implementation and treatment, it is vital to implement preventive measures and to closely monitor skin health in at-risk areas.

Proning the extracorporeal membrane oxygenation plus Impella: a case report

Background

The prone position is recommended as supportive therapy in patients with moderate-to-severe acute respiratory distress syndrome (ARDS). However, little is known about prone position ventilation in patients with cardiogenic shock supported by extracorporeal membrane oxygenation (ECMO) plus Impella (ECPELLA) developing ARDS.

Case summary

A 66-year-old man with severe left ventricular dysfunction was admitted to a non-academic ECMO centre for a high-risk coronary artery bypass grafting. He developed post-cardiotomy shock needing ECMO support. To improve left ventricular unloading, an Impella was inserted 2 days later. One day later, he developed ARDS and needed prone position ventilation with ECPELLA in situ. After 4 weeks, he was discharged from the intensive care unit.

Discussion

Previous studies demonstrated that prone positioning could help avoid an additional venous cannula in veno-arterial ECMO patients, which is associated with mechanical complications. In this case, there was a promising role for unloading the left ventricle with Impella during veno-arterial ECMO and, for proning, the patient with cardiogenic shock developing ARDS during ECMO support without the need for an extra venous cannula.

Pressure ulcers after prone positioning in patients undergoing extracorporeal membrane oxygenation: A cross-sectional study

BACKGROUND

The combination of prone positioning and extracorporeal membrane oxygenation (ECMO) in patients with acute respiratory distress syndrome (ARDS) is recognized as safe but its use has been limited due to potential complications.

AIM

To report the prevalence of pressure ulcers and other complications due to prone positioning in adult patients receiving veno-venous ECMO.

STUDY DESIGN

This cross-sectional study was conducted in a tertiary level intensive care unit (ICU) in Milan (Italy), between January 2015 and December 2019. The study population was critically ill adult patients undergoing veno-venous ECMO. Statistical association between pressure ulcers and the type of body positioning (prone versus supine) was explored fitting a logistic model.

RESULTS

In the study period, 114 patients were treated with veno-venous ECMO and 62 (54.4%) patients were placed prone for a total of 130 prone position cycles. ECMO cannulation was performed via femoro-femoral configuration in the majority of patients (82.4%, 94/114). Pressure ulcers developed in 57.0% of patients (95%CI: 44.0%-72.6%), most often arising on the face and the chin (37.1%, 23/62), particularly in those placed prone. The main reason of prone positioning interruption was the decrease of ECMO blood flow (8.1%, 5/62). The fitted model showed no association between body position during ECMO and occurrence of pressure ulcers (OR 1.3, 95%CI: 0.5-3.6, p = .532).

CONCLUSIONS

Facial pressure ulcers were the most frequent complications of prone positioning. Nurses should plan and implement evidence-based care to prevent such pressure injuries in patients undergoing ECMO.

RELEVANCE TO CLINICAL PRACTICE

The combination of prone positioning and ECMO shows few life-threating complications. This manoeuvre during ECMO is feasible and safe when performed by experienced ICU staff.

Use of prone position ventilation in patients with COVID-19 induced severe ARDS supported with V-V ECMO: A danish cohort study with focus on adverse events

INTRODUCTION

Prone position ventilation (PPV) of patients with adult respiratory distress syndrome (ARDS) supported with veno-venous extracorporeal membrane oxygenation (V-V ECMO) may improve oxygenation and alveolar recruitment and is recommended when extensive dorsal consolidations are present, but only few data regarding adverse events (AE) related to PPV in this group of patients have been published.

METHODS

Nationwide retrospective analysis of 68 COVID-19 patients admitted from March 2020 - December 2021 with severe ARDS and need of V-V ECMO support. The number of patients treated with PPV, number of PPV-events, timing, the time spent in prone position, number and causes of AE are reported. Causes to stop the PPV regimen and risk factors for AE were explored.

RESULTS

44 out of 68 patients were treated with PPV, and 220 PPV events are evaluated. AE were identified in 99 out of 220 (45%) PPV events and occurred among 31 patients (71%). 1 fatal PPV related AE was registered. Acute supination occurred in 19 events (9%). Causes to stop the PPV regimen were almost equally distributed between effect (weaned from ECMO), no effect, death (of other reasons) and AE. Frequent causes of AE were pressures sores and ulcers, hypoxia, airway related and ECMO circuit related. Most AE occurred during patients first or second PPV event.

CONCLUSIONS

PPV treatment was found to carry a high incidence of PPV related AE in these patients. Causes and preventive measures to reduce occurrence of PPV related AE during V-V ECMO support need further exploration.

Impact of prone positioning duration on the outcome of patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: A meta-analysis

Purpose

Research has shown that prone positioning (PP) improves the survival of patients receiving venovenous extracorporeal membrane oxygenation (V-V ECMO) for acute respiratory distress syndrome (ARDS). However, the reported impact of PP duration on the outcome of V-V ECMO patients with ARDS varies across studies.

Methods

A meta-analysis approach was used to identify studies that investigated the impact of PP duration on the outcome of ARDS patients who were treated with V-V ECMO; the following databases were used: MEDLINE, Embase, Wanfang, and the China National Knowledge Infrastructure. The primary outcome was cumulative survival. Secondary outcomes were length of stay in an intensive care unit, exchange of arterial blood gases, and adverse events.

Results

A total of 8 studies were included in the final meta-analysis. Patients with longer duration of PP (≥12 h) had a longer survival period (risk ratio: 1.24; 95% confidence interval: 1.00, 1.54]) than those with PP < 12 h. There was no evidence of publication bias across the studies.

Conclusion

Our results imply that a longer duration of PP ≥ 12 h might improve the outcome of patients with ARDS who receive V-V ECMO therapy.

Prone positioning in ARDS patients supported with VV ECMO, what we should explore?

Background

Acute respiratory distress syndrome (ARDS), a prevalent cause of admittance to intensive care units, is associated with high mortality. Prone positioning has been proven to improve the outcomes of moderate to severe ARDS patients owing to its physiological effects. Venovenous extracorporeal membrane oxygenation (VV ECMO) will be considered in patients with severe hypoxemia. However, for patients with severe hypoxemia supported with VV ECMO, the potential effects and optimal strategies of prone positioning remain unclear. This review aimed to present these controversial questions and highlight directions for future research.

Main body

The clinically significant benefit of prone positioning and early VV ECMO alone was confirmed in patients with severe ARDS. However, a number of questions regarding the combination of VV ECMO and prone positioning remain unanswered. We discussed the potential effects of prone positioning on gas exchange, respiratory mechanics, hemodynamics, and outcomes. Strategies to achieve optimal outcomes, including indications, timing, duration, and frequency of prone positioning, as well as the management of respiratory drive during prone positioning sessions in ARDS patients receiving VV ECMO, are challenging and controversial. Additionally, whether and how to implement prone positioning according to ARDS phenotypes should be evaluated. Lung morphology monitored by computed tomography, lung ultrasound, or electrical impedance tomography might be a potential indication to make an individualized plan for prone positioning therapy in patients supported with VV ECMO.

Conclusion

For patients with ARDS supported with VV ECMO, the potential effects of prone positioning have yet to be clarified. Ensuring an optimal strategy, especially an individualized plan for prone positioning therapy during VV ECMO, is particularly challenging and requires further research.

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

Background

The application of prone position (PP) in acute respiratory distress syndrome (ARDS) supported by venovenous extracorporeal membrane oxygenation (VV-ECMO) is controversial.

Objectives

To evaluate the safety and efficacy of application of PP during VV-ECMO in patients with ARDS.

Methods

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.

Results

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).

Conclusions

PP during VV-ECMO was safe and could improve oxygenation. A large-scale and well-designed RCT is needed in the future.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-02026-7.

Effect of prone positioning on survival in adult patients receiving venovenous extracorporeal membrane oxygenation for acute respiratory distress syndrome: a systematic review and meta-analysis

Purpose

Previous studies support the potential efficacy of venovenous extracorporeal membrane oxygenation (vvECMO) for improving survival in severe acute respiratory distress syndrome (ARDS) cases. Prone positioning (PP) has been shown to improve the outcomes of moderate-to-severe ARDS patients. Few studies and no randomized controlled trials have evaluated the effect of PP performed in ECMO patients.

Methods

We performed a systematic review and meta-analysis examining the effect of prone positioning for ARDS patients receiving vvECMO on survival. All authors were contacted to obtain complementary information not mentioned in the original articles. The main objective was to compare 28-day survival in vvECMO patients with PP to vvECMO patients without PP (controls).

Results

Thirteen studies with a combined population of 1836 patients satisfied the inclusion criteria. PP was associated with a significant improvement in 28-day survival (503 survivors among 681 patients in the PP group [74%; 95% CI 71–77] vs. 450 survivors among 770 patients in the control group [58%, 95% CI 55–62]; RR 1.31 [95% CI 1.21–1.41]; I² 22% [95% CI 0–62%]; P < 0.0001). Survival was also improved in terms of other endpoints (60-day survival, 90-day survival, ICU survival, and hospital survival). In contrast, the duration of mechanical ventilation was increased in vvECMO patients with PP (mean difference 11.4 days [95% CI 9.2–13.5]; 0.64 [95% CI 0.50–0.78]; I² 8%; P < 0.0001).

Conclusion

According to this meta-analysis, survival was improved when prone positioning was used in ARDS patients receiving vvECMO. The impact of this combination on survival should be investigated in prospective randomized controlled trials.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00134-021-06604-x.

To prone or not to prone ARDS patients on ECMO

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2021. Other selected articles can be found online at  https://www.biomedcentral.com/collections/annualupdate2021 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from  https://link.springer.com/bookseries/8901 .

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

A single-centre study of safety and efficacy of prone positioning for critically ill patients on veno-venous extracorporeal membrane oxygenation

BACKGROUND

Veno-venous extracorporeal membrane oxygenation (VV-ECMO) may be used for patients with severe respiratory failure. Prone positioning may also be worthwhile using while patients are on VV-ECMO to promote return of native lung function.

OBJECTIVES

The aim of the study was to determine if the use of prone positioning in adult patients receiving VV-ECMO improved oxygenation, shortened the time on ECMO, and led to earlier liberation from ECMO compared with no prone positioning. We also wished to determine the incidence of pressure injury development in patients receiving prone positioning.

METHODS

This was a single-centre, retrospective cohort study of patients on VV-ECMO over 5 years at a national ECMO centre.

FINDINGS

Between July 1, 2014, and July 1, 2019, 72 patients were admitted to the cardiothoracic and vascular intensive care unit for VV-ECMO owing to respiratory failure. Patients were aged on average 46 years, male (n = 46, 64%), and New Zealand Europeans (n = 45, 63%). The most common diagnosis was pneumonia, the median ECMO treatment duration was 278 h, and 50 patients (69%) of the cohort survived to 6 months. Of these, 16 (22%) received at least one pronation procedure whilst on ECMO. Pronation increased oxygenation ratio although not significantly, and this increase was not sustained once returned to the supine position. Pronation was instituted late in the ECMO course and was not associated with complications. Prone episodes were carried out in a safe manner with few adverse events or complications.

CONCLUSIONS

In patients requiring VV-ECMO support, prone positioning would appear to be a safe intervention when carried out by an experienced team.

Prone positioning in severe ARDS requiring extracorporeal membrane oxygenation

Background

Prone positioning (PP) has shown to improve survival in patients with severe acute respiratory distress syndrome (ARDS). To this point, it is unclear if PP is also beneficial for ARDS patients treated with veno-venous extracorporeal membrane oxygenation (VV ECMO) support.

Methods

We report retrospective data of a single-centre registry of patients with severe ARDS requiring VV ECMO support between October 2010 and May 2018. Patients were allocated to the PP group if PP was performed during VV ECMO treatment or the supine positioning group. VV ECMO weaning success and hospital survival were analysed before and after propensity score matching.

Results

A total of 158 patients could be analysed, and 38 patients (24.1%) received PP. There were no significant differences in VV ECMO weaning rate (47.4% vs. 46.7%, p = 0.94) and hospital survival (36.8% vs. 36.7%, p = 0.98) between the prone and supine groups, respectively. The analysis of 38 propensity score matched pairs also showed no difference in hospital survival (36.8% vs. 36.8%, p = 1.0) or VV ECMO weaning rate (47.4% vs. 44.7%, p = 0.82). Hospital survival was superior in the subgroup of patients treated with early PP (cutoff < 17 h via Youden’s Index) as compared to late or no PP (81.8% vs. 33.3%, p = 0.02).

Conclusion

In this propensity score matched cohort of severe ARDS patients requiring VV ECMO support, prone positioning at any time was not associated with improved weaning or survival. However, early initiation of prone positioning was linked to a significant reduction of hospital mortality.

Prone position and extracorporeal membrane oxygenation in acute respiratory distress syndrome

Abstract Introduction: The acute respiratory distress syndrome is an inflammatory process originated by some pulmonary diseases, resulting in non-hydrostatic protein edema of the pulmonary parenchyma. The loss of the lung ability to eliminate carbon dioxide generates complications such as refractory hypoxemia, decreased alveolar dysplasia, increased complacency and hypercarbia. The treatment of acute respiratory distress syndrome, consist in measures to prevent lung diseases progression and optimize oxygenation. Objective: To identify, in the international scientific literature, cases or series of cases reporting the combined application of prone position and extracorporeal membrane oxygenation in patients with severe acute respiratory distress syndrome, as well as the benefit of these rescue therapies. Method: This is a systematic review of case reports that show the benefit of combined therapies in the treatment of patients with acute respiratory distress syndrome. Results: From the research strategy and selection criteria were included 8 studies reporting 19 cases of patients with acute respiratory distress syndrome who received the combination of the two rescue therapies. All studies showed that extracorporeal membrane oxygenation was the primary intervention. There were no reports of adverse events. Conclusion: The combinations of therapies positively interfere on the prognosis of patients with acute respiratory distress syndrome, in addition to presenting no additional risks in terms of the occurrence of adverse events; however, the prone position should precede the extracorporeal membrane oxygenation as first-line intervention. PROSPERO Registration No. CRD42018093076

Mechanical ventilation and respiratory monitoring during extracorporeal membrane oxygenation for respiratory support

Over the past decade, the use of veno-venous extracorporeal membrane oxygenation (VV-ECMO) for respiratory support has widely expanded as a treatment strategy for patients with acute respiratory distress syndrome (ARDS). Despite considerable attention has been given to the indications, the timing and the management of patients undergoing ECMO for refractory respiratory hypoxemic failure, little is known regarding the management of mechanical ventilation (MV) in this group of patients. ECMO enables to minimize ventilatory induced lung injury (VILI) and it has been successfully used as rescue therapy in patients with ARDS when conventional ventilator strategies have failed. However, literature is lacking regarding the best strategies and MV settings, including positive end expiratory pressure (PEEP), tidal volume (VT), respiratory rate (RR) and plateau pressure (PPLAT). The aim of this review is to summarize current evidence, the rationale and provide recommendations about the best ventilator strategy to adopt in patients with ARDS undergoing VV-ECMO support.

Application of prone position in hypoxaemic patients supported by veno-venous ECMO

INTRODUCTION

Veno-Venous Extracorporeal Membrane Oxygenation (VV-ECMO) is an advanced respiratory care therapy allowing replacement of pulmonary gas exchange. Despite VV-ECMO support, some patients may remain hypoxaemic. A possible therapeutic procedure for these patients is the application of prone positioning.

OBJECTIVE

The primary aim of the present study was to investigate modification of the PaO₂/FiO₂ ratio, in VV-ECMO patients with refractory hypoxaemia. The secondary aim was to evaluate the safety and feasibility of prone positioning for patients with severe Adult Respiratory Distress Syndrome supported by ECMO.

METHODS

We retrospectively reviewed the electronic records and charts of all patients supported by VV-ECMO who experienced at least one pronation. Complications related with prone positioning were also recorded. First PaO₂/FiO₂ ratio was analysed during four different time steps: before pronation, one hour after pronation, at the end of pronation and one hour after returning to supine.

RESULTS

A total of 45 prone positioning manoeuvers were performed in 14 VV-ECMO patients from November 2009 to November 2014. The median duration of prone positioning cycles was 8 hours (IQR 6-10). No accidental dislodgement of intravascular lines, endotracheal tubes, chest tubes or a decrease in ECMO blood flow was observed. During the first prone positioning for each patient, the median PaO₂/FiO₂ ratio recorded was 123 (IQR 82-135), 152 (93-185), 149 (90-186) and 113 (74-182), during PRE-supine step, 1 h-prone positioning step, END-prone positioning step, and POST-supine step respectively.

CONCLUSIONS

The application of prone positioning during VV-ECMO has shown to be a safe and reliable technique when performed in a recognised ECMO centre with the appropriately trained staff and standard procedures.

Extracorporeal membrane oxygenation in spina bifida and (H1N1)-induced acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is characterized as an acute hypoxemic and/or hypercapnic respiratory failure seen in critically ill patients and is still, although decreased over the past few years, associated with high mortality. Furthermore, ARDS may be a life-threatening complication of H1N1 pneumonia. We report on a 45-year-old spina bifida patient with confirmed H1N1 influenza virus infection causing acute respiratory failure, who was successfully weaned from 42-day veno-venous extracorporeal membrane oxygenation (vv-ECMO) treatment with an excellent outcome. Due to the physical constitution of spina bifida patients, we experienced challenges concerning cannula positioning and mechanical ventilation settings during weaning.

Veno-arterial-ECMO in the intensive care unit: From technical aspects to clinical practice

The use of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) as a salvage therapy in cardiogenic shock is becoming of current practice. While VA-ECMO is potentially a life-saving technique, results are sometimes mitigated, emphasising the need for selecting the right indication in the right patient. This relies upon a clear definition of the individual therapeutic project, including the potential for recovery as well as the possible complications associated with VA-ECMO. To maximise the benefits of VA-ECMO, the basics of extracorporeal circulation should be perfectly understood since VA-ECMO can sometimes be detrimental. Hence, to be successful, VA-ECMO should be used by teams with sufficient experience and initiated after a thorough multidisciplinary discussion considering patient's medical history, pathology as well the anticipated evolution of the disease.

Mechanical Ventilation during Extracorporeal Membrane Oxygenation in Patients with Acute Severe Respiratory Failure

Conventionally, a substantial number of patients with acute respiratory failure require mechanical ventilation (MV) to avert catastrophe of hypoxemia and hypercapnia. However, mechanical ventilation per se can cause lung injury, accelerating the disease progression. Extracorporeal membrane oxygenation (ECMO) provides an alternative to rescue patients with severe respiratory failure that conventional mechanical ventilation fails to maintain adequate gas exchange. The physiology behind ECMO and its interaction with MV were reviewed. Next, we discussed the timing of ECMO initiation based on the risks and benefits of ECMO. During the running of ECMO, the protective ventilation strategy can be employed without worrying about catastrophic hypoxemia and carbon dioxide retention. There is a large body of evidence showing that protective ventilation with low tidal volume, high positive end-expiratory pressure, and prone positioning can provide benefits on mortality outcome. More recently, there is an increasing popularity on the use of awake and spontaneous breathing for patients undergoing ECMO, which is thought to be beneficial in terms of rehabilitation.

Clinical Practice Guideline of Acute Respiratory Distress Syndrome

There is no well-stated practical guideline for mechanically ventilated patients with or without acute respiratory distress syndrome (ARDS). We generate strong (1) and weak (2) grade of recommendations based on high (A), moderate (B) and low (C) grade in the quality of evidence. In patients with ARDS, we recommend low tidal volume ventilation (1A) and prone position if it is not contraindicated (1B) to reduce their mortality. However, we did not support high-frequency oscillatory ventilation (1B) and inhaled nitric oxide (1A) as a standard treatment. We also suggest high positive end-expiratory pressure (2B), extracorporeal membrane oxygenation as a rescue therapy (2C), and neuromuscular blockage for 48 hours after starting mechanical ventilation (2B). The application of recruitment maneuver may reduce mortality (2B), however, the use of systemic steroids cannot reduce mortality (2B). In mechanically ventilated patients, we recommend light sedation (1B) and low tidal volume even without ARDS (1B) and suggest lung protective ventilation strategy during the operation to lower the incidence of lung complications including ARDS (2B). Early tracheostomy in mechanically ventilated patients can be performed only in limited patients (2A). In conclusion, of 12 recommendations, nine were in the management of ARDS, and three for mechanically ventilated patients.

[Short version S2e guidelines: "Positioning therapy and early mobilization for prophylaxis or therapy of pulmonary function disorders"]

The German Society of Anesthesiology and Intensive Care Medicine (DGAI) commissioned a revision of the S2 guidelines on "positioning therapy for prophylaxis or therapy of pulmonary function disorders" from 2008. Because of the increasing clinical and scientific relevance the guidelines were extended to include the issue of "early mobilization" and the following main topics are therefore included: use of positioning therapy and early mobilization for prophylaxis and therapy of pulmonary function disorders, undesired effects and complications of positioning therapy and early mobilization as well as practical aspects of the use of positioning therapy and early mobilization. These guidelines are the result of a systematic literature search and the subsequent critical evaluation of the evidence with scientific methods. The methodological approach for the process of development of the guidelines followed the requirements of evidence-based medicine, as defined as the standard by the Association of the Scientific Medical Societies in Germany. Recently published articles after 2005 were examined with respect to positioning therapy and the recently accepted aspect of early mobilization incorporates all literature published up to June 2014.

[Prone positioning of patients during venovenous extracorporeal membrane oxygenation is safe and feasible]

BACKGROUND

Prone positioning of patients with acute respiratory distress syndrome (ARDS) has been shown to significantly improve survival rates. Prone positioning reduces collapse of dorsal lung segments with subsequent reduction of alveolar overdistension of ventral lung segments, optimizes lung recruitment and enhances drainage. Patients with ARDS treated by extracorporeal membrane oxygenation (ECMO) can also benefit from prone positioning; however, the procedure is associated with a possible higher risk of serious adverse events.

OBJECTIVE

The aim of this study was to evaluate the safety and feasibility of prone positioning for patients with severe ARDS during ECMO therapy.

MATERIAL AND METHODS

This study involved a retrospective analysis of all patients placed in a prone position while being treated by venovenous ECMO (vvECMO) for severe hypoxemia in ARDS as bridge to recovery in the interdisciplinary intensive care unit at the University Hospital Leipzig between January 2009 and August 2013. Baseline data, hospital mortality and serious adverse events were documented. Serious adverse events were defined as dislocation or obstruction of endotracheal tube or tracheal cannula, ECMO cannulas and cardiac arrest. Prone positioning was carried out by at least one doctor and three nurses according to a standardized protocol. Results are given as the median (1st and 3rd quartiles).

RESULTS

A total of 26 patients were treated with vvECMO as bridge to recovery due to severe ARDS. Causes for ARDS were pneumonia (n = 20) and aspiration (n = 2) and four patients had different rare causes of ARDS. The median time on ECMO was 8 days (6;11) and during this period 134 turning events were documented. Patients were proned for a median of 5 (3;7) periods with a median duration of 12 h (8;12). No serious adverse events were recorded. The hospital mortality was 42% and mortality during the ECMO procedure was 35%.

CONCLUSION

Prone positioning significantly reduces the mortality of patients with severe ARDS. In this series of 26 patients with severe ARDS during ECMO therapy no serious adverse events were found during the use of prone positioning.

S2e guideline: positioning and early mobilisation in prophylaxis or therapy of pulmonary disorders : Revision 2015: S2e guideline of the German Society of Anaesthesiology and Intensive Care Medicine (DGAI)

The German Society of Anesthesiology and Intensive Care Medicine (DGAI) commissioneda revision of the S2 guidelines on "positioning therapy for prophylaxis or therapy of pulmonary function disorders" from 2008. Because of the increasing clinical and scientificrelevance the guidelines were extended to include the issue of "early mobilization"and the following main topics are therefore included: use of positioning therapy and earlymobilization for prophylaxis and therapy of pulmonary function disorders, undesired effects and complications of positioning therapy and early mobilization as well as practical aspects of the use of positioning therapy and early mobilization. These guidelines are the result of a systematic literature search and the subsequent critical evaluation of the evidence with scientific methods. The methodological approach for the process of development of the guidelines followed the requirements of evidence-based medicine, as defined as the standard by the Association of the Scientific Medical Societies in Germany. Recently published articles after 2005 were examined with respect to positioning therapy and the recently accepted aspect of early mobilization incorporates all literature published up to June 2014.

Prolonged prone positioning under VV-ECMO is safe and improves oxygenation and respiratory compliance

Background

Data are sparse regarding the effects of prolonged prone positioning (PP) during VV-ECMO. Previous studies, using short sessions (<12 h), failed to find any effects on respiratory system compliance. In the present analysis, the effects of prolonged PP sessions (24 h) were retrospectively studied with regard to safety data, oxygenation and respiratory system compliance.

Methods

Retrospective review of 17 consecutive patients who required both VV-ECMO and prone positioning. PP under VV-ECMO was considered when the patient presented at least one unsuccessful ECMO weaning attempt after day 7 or refractory hypoxemia combined or not with persistent high plateau pressure. PP sessions had a duration of 24 h with fixed ECMO and respiratory settings. PP was not performed in patients under vasopressor treatment and in cases of recent open chest cardiac surgery.

Results

Despite optimized protective mechanical ventilation and other adjuvant treatment (i.e. PP, inhaled nitric oxide, recruitment maneuvers), 44 patients received VV-ECMO during the study period for refractory acute respiratory distress syndrome. Global survival rate was 66 %. Among the latter, 17 patients underwent PP during VV-ECMO for a total of 27 sessions. After 24 h in prone position, PaO₂/FiO₂ ratio significantly increased from 111 (84–128) to 173 (120–203) mmHg (p < 0.0001) while respiratory system compliance increased from 18 (12–36) to 32 (15–36) ml/cmH₂O (p < 0.0001). Twenty-four hours after the return to supine position, tidal volume was increased from 3.0 (2.2–4.0) to 3.7 (2.8–5.0) ml/kg (p < 0.005). PaO₂/FiO₂ ratio increased by over 20 % in 14/14 sessions for late sessions (≥7 days) and in 7/13 sessions for early sessions (<7 days) (p = 0.01). Quantitative CT scan revealed a high percentage of non-aerated or poorly-aerated lung parenchyma [52 % (41–62)] in all patients. No correlation was found between CT scan data and respiratory parameter changes. Hemodynamics did not vary and side effects were rare (one membrane thrombosis and one drop in ECMO blood flow).

Conclusion

When used in combination with VV-ECMO, 24 h of prone positioning improves both oxygenation and respiratory system compliance. Moreover, our study confirms the absence of serious adverse events.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-015-0078-4) contains supplementary material, which is available to authorized users.

Mechanical ventilation during extracorporeal life support (ECLS): a systematic review

PURPOSE

In patients with acute respiratory distress syndrome (ARDS), extracorporeal life support (ECLS) has been utilized to support gas exchange and mitigate ventilator-induced lung injury (VILI). The optimal ventilation settings while on ECLS are unknown. The purpose of this systematic review is to describe the ventilation practices in patients with ARDS who require ECLS.

METHODS

We electronically searched MEDLINE, EMBASE, CENTRAL, AMED, and HAPI (inception to January 2015). Studies included were randomized controlled trials, observational studies, or case series (≥4 patients) of ARDS patients undergoing ECLS. Our review focused on studies describing ventilation practices employed during ECLS for ARDS.

RESULTS

Forty-nine studies (2,042 patients) met our inclusion criteria. Prior to initiation of ECLS, at least one parameter consistent with injurious ventilation [tidal volume >8 mL/kg predicted body weight (PBW), peak pressure >35 cmH2O (or plateau pressure >30 cmH2O), or FiO2 ≥0.8] was noted in 90% of studies. After initiation of ECLS, studies reported median [interquartile range (IQR)] reductions in: tidal volume [2.4 mL/kg PBW (2.2-2.9)], plateau pressure [4.3 cmH2O (3.5-5.8)], positive end-expiratory pressure (PEEP) [0.20 cmH2O (0-3.0)], and FiO2 [0.40 (0.30-0.60)]. Median (IQR) overall mortality was 41 % (31-51%).

CONCLUSIONS

Reduction in the intensity of mechanical ventilation in patients with ARDS supported by ECLS is common, suggesting that clinicians may be focused on reducing VILI after ECLS initiation. Future investigations should focus on establishing the optimal ventilatory strategy for patients with ARDS who require ECLS.