Catastrophic Mechanical Complications of Extracorporeal Membrane Oxygenation

Awake Venovenous Extracorporeal Membrane Oxygenation in the Intensive Care Unit: Challenges and Emerging Concepts

Extracorporeal membrane oxygenation (ECMO) is an advanced treatment for severe respiratory failure. Implantation of ECMO before invasive ventilation or extubation during ECMO has been reported and is becoming increasingly popular. Avoidance of sedation and invasive ventilation during ECMO (commonly referred to as "awake ECMO") may have potential advantages, including a lower rate of delirium, shorter mechanical ventilation time, and the possibility of undergoing early rehabilitation and/or physiotherapy. However, awake ECMO is also associated with several risks, such as self-inflicted lung injury and cannula displacement or self-removal. Accordingly, invasive ventilation before ECMO, as well as weaning from ECMO before weaning from mechanical ventilation, remain the most common approaches. In this review, the authors describe indications, contraindications, advantages, disadvantages, and current evidence on the use of ECMO without invasive ventilation in patients with respiratory failure.

Optimizing the safety and efficacy of the awake venovenous extracorporeal membrane oxygenation in patients with COVID-19-related ARDS

BACKGROUND

Maintaining the patient awake and not intubated during the venovenous extracorporeal membrane oxygenation (VV ECMO) reduces the risk of ventilation-induced lung injury in patients with ARDS. Currently, there is a lack of data on outcomes and complications associated with the awake ECMO approach.

OBJECTIVES

To evaluate outcomes and the occurrence of complications of awake ECMO approach guided by local safety protocol comprising ultrasound-guided cannulation, argatroban-based anticoagulation, respiratory support, and routine sedation targeted to reduce respiratory effort and keeping nurse-to-patient ratio of 1:1.

DESIGN

A single-center retrospective case series analysis.

METHODS

Consecutive patients with COVID-19-related acute respiratory distress syndrome (ARDS) (CARDS) treated by full awake VV ECMO approach from April 2019 to December 2023 were eligible.

RESULTS

Our center treated 10 patients (mean age 54.7 ± 11.6 years) with CARDS with an awake ECMO approach. The reasons for awake ECMO included the presence of barotrauma in six patients, a team consensus to prefer awake ECMO instead of mechanical ventilation in three patients, and the patient's refusal to be intubated in one case. Before ECMO, patients were severely hypoxemic, with a mean value of Horowitz index of 48.9 ± 9.1 mmHg and a mean respiratory rate of 28.8 ± 7.3 breaths per minute on high-flow nasal cannula or noninvasive ventilation support. The mean duration of awake VV ECMO was 558.0 ± 173.6 h. Seven patients (70%) were successfully disconnected from ECMO and fully recovered. Intubation from respiratory causes was needed in three patients (30%), all of whom died eventually. In total, three episodes of delirium, two episodes of significant bleeding, one pneumothorax requiring chest tube insertion, and one oxygenator acute exchange occurred throughout the 5580 h of awake ECMO. No complications related to cannula displacement or malposition occurred.

CONCLUSION

The awake ECMO strategy guided by safety protocol appears to be a safe approach in conscious, severely hypoxemic, non-intubated patients with COVID-19-related ARDS.

Extracorporeal Membrane Oxygenation Without Invasive Ventilation for Respiratory Failure in Adults: A Systematic Review

OBJECTIVES

Extracorporeal membrane oxygenation (ECMO) is an advanced treatment for acute severe respiratory failure. Patients on ECMO are frequently maintained sedated and immobilized until weaning from ECMO, first, and then from mechanical ventilation. Avoidance of sedation and invasive ventilation during ECMO may have potential advantages. We performed a systematic literature review to assess efficacy and safety of awake ECMO without invasive ventilation in patients with respiratory failure.

DATA SOURCES

PubMed, Web of Science, and Scopus were searched for studies reporting outcome of awake ECMO for adult patients with respiratory failure.

STUDY SELECTION

We included all studies reporting outcome of awake ECMO in patients with respiratory failure. Studies on ECMO for cardiovascular failure, cardiac arrest, or perioperative support and studies on pediatric patients were excluded. Two investigators independently screened and selected studies for inclusion.

DATA EXTRACTION

Two investigators abstracted data on study characteristics, rate of awake ECMO failure, and mortality. Primary outcome was rate of awake ECMO failure (need for intubation). Pooled estimates with corresponding 95% CIs were calculated. Subgroup analyses by setting were performed.

DATA SYNTHESIS

A total of 57 studies (28 case reports) included data from 467 awake ECMO patients. The subgroup of patients with acute respiratory distress syndrome showed a pooled estimate for awake ECMO failure of 39.3% (95% CI, 24.0-54.7%), while in patients bridged to lung transplantation, pooled estimate was 23.4% (95% CI, 13.3-33.5%). Longest follow-up mortality was 121 of 439 (pooled estimate, 28%; 95% CI, 22.3-33.6%). Mortality in patients who failed awake ECMO strategy was 43 of 74 (pooled estimate, 57.2%; 95% CI, 40.2-74.3%). Two cases of cannula self-removal were reported.

CONCLUSIONS

Awake ECMO is feasible in selected patients, although the effect on outcome remains to be demonstrated. Mortality is almost 60% in patients who failed awake ECMO strategy.

Overlooked but Serious Gallbladder Disease during Extracorporeal Membrane Oxygenation: A Retrospective Analysis

Background: To date, there have been no reports assessing the incidence, risk factors, and clinical outcomes of GB disease in patients receiving ECMO for cardiorespiratory failure. Methods: The medical records of adults (aged > 18 years) who underwent ECMO between May 2010 and October 2019 were retrospectively reviewed. We investigated the prevalence and related factors of GB disease during ECMO therapy, compared clinical outcomes between patients with and without GB disease, and performed propensity-matched analysis. Results: In total, 446 patients were included, and symptomatic GB disease was found in 62 patients (13.9%, 76.2/1000 ECMO days). Complicated GB disease occurred in 42 patients (9.4%, 89.4/1000 ECMO days) and presented as acute cholecystitis, acute cholangitis, and biliary pancreatitis in 33 (7.4%), 7 (1.6%), and 5 (1.1%) patients, respectively. In multivariate Cox regression analysis, longer ECMO support (>2 weeks) (hazard ratio (HR), 2.95; 95% confidence interval (CI), 1.69−5.15) and elevated plasma hemoglobin (Hb, >50 mg/dL) (HR. 2.12; 95% CI, 1.18−3.78) were significantly associated with the development of GB disease. In the propensity-matched cohort, the intensive care unit (ICU) and hospital survival rates were significantly lower for patients with GB disease than for those without GB disease (ICU survival rate, 64.5% vs. 84.7%; hospital survival rate, 59.7% vs. 81.5%). Conclusion: The incidence of GB disease was higher in patients who received ECMO than in the general ICU patients. Furthermore, elevated plasma Hb and prolonged ECMO therapy were significant factors for the development of GB disease during ECMO therapy.

Awake Extracorporeal Membrane Oxygenation for Acute Respiratory Distress Syndrome: Which Clinical Issues Should Be Taken Into Consideration

With the goal of protecting injured lungs and extrapulmonary organs, venovenous extracorporeal membrane oxygenation (VV-ECMO) has been increasingly adopted as a rescue therapy for patients with severe acute respiratory distress syndrome (ARDS) when conventional mechanical ventilation failed to provide effective oxygenation and decarbonation. In recent years, it has become a promising approach to respiratory support for awake, non-intubated, spontaneously breathing patients with respiratory failure, referred to as awake ECMO, to avoid possible detrimental effects associated with intubation, mechanical ventilation, and the adjunctive therapies. However, several complex clinical issues should be taken into consideration when initiating and implementing awake ECMO, such as selecting potential patients who appeared to benefit most; techniques to facilitating cannulation and maintain stable ECMO blood flow; approaches to manage pain, agitation, and delirium; and approaches to monitor and modulate respiratory drive. It is worth mentioning that there had also been some inherent disadvantages and limitations of awake ECMO compared to the conventional combination of ECMO and invasive mechanical ventilation. Here, we review the use of ECMO in awake, spontaneously breathing patients with severe ARDS, highlighting the issues involving bedside clinical practice, detailing some of the technical aspects, and summarizing the initial clinical experience gained over the past years.