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

Neurological Complications of the Lower Extremities After Femoral Cannulated Extracorporeal Membrane Oxygenation: A Systematic Review

BACKGROUND

Femoral cannulated extracorporeal membrane oxygenation (ECMO) has been associated with neurologic complications in the lower extremity ipsilateral to the cannulation. There is uncertainty about the prevalence of these complications and their mechanisms of development.

OBJECTIVE

Aim of this systematic review was to investigate the prevalence of neurological complications after ECMO and to describe possible underlying mechanisms.

METHOD

A systematic literature search was performed in Medline-Ovid, Embase, Cochrane Library, CINAHL, and PEDro until April 2021 for clinical trials in English or German language which quantified neurologic complications in the lower extremity ipsilateral to the ECMO cannulation of adults. The complications had to be delimitable to intensive care unit-acquired weakness. Methodological quality was assessed by 2 independent investigators using the Quality Assessment Tool for Observational Cohort and Cross-Sectional Studies of the National Heart, Lung, and Blood Institute.

RESULTS

Eight observational studies were included in the synthesis. Study quality was good to fair in 88% of the papers. Overall, 47 of 202 patients (23.3%; ranging from 3% to 48% across studies) with femoral ECMO cannulation showed neurologic complications of the lower extremity ipsilateral to the cannulation. Peripheral ischemia and compression of nerves by the ECMO cannula are discussed as mechanisms of injury.

CONCLUSION

The occurrence of neurological complications after ECMO was common and can lead to long-term impairment. The mechanisms are largely unknown but currently there is no sufficient evidence for the involvement of ECMO. Standardized assessments are needed to systematically screen for neurological complications early after ECMO, to enable countermeasures and prevent further complications.

Extracorporeal membrane oxygenation versus invasive ventilation in patients with COVID-19 acute respiratory distress syndrome and pneumomediastinum: A cohort trial

BACKGROUND

Patients with severe respiratory failure due to COVID-19 who are not under mechanical ventilation may develop severe hypoxemia when complicated with spontaneous pneumomediastinum (PM). These patients may be harmed by invasive ventilation. Alternatively, veno-venous (V-V) extracorporeal membrane oxygenation (ECMO) may be applied. We report on the efficacy of V-V ECMO and invasive ventilation as initial advanced respiratory support in patients with COVID-19 and acute respiratory failure due to spontaneous PM.

METHODS

This was a retrospective cohort study performed between March 2020 and January 2022. Enrolled patients had COVID-19 and acute respiratory failure due to spontaneous PM and were not invasively ventilated. Patients were treated in the intensive care unit (ICU) with invasive ventilation (invasive ventilation group) or V-V ECMO support (V-V ECMO group) as the main therapeutic option. The primary outcomes were mortality and ICU discharge at 90 days after ICU admission.

RESULTS

Twenty-two patients were included in this study (invasive ventilation group: 13 [59%]; V-V ECMO group: 9 [41%]). The V-V ECMO strategy was significantly associated with lower mortality (hazard ratio [HR] 0.33 [95% CI 0.12-0.97], p = 0.04). Five (38%) patients in the V-V ECMO group were intubated and eight (89%) patients in the invasive ventilation group required V-V ECMO support within 30 days from ICU admission. Three (33%) patients in the V-V ECMO group were discharged from ICU within 90 days compared to one (8%) patient in the invasive ventilation group (HR 4.71 [95% CI 0.48-45.3], p = 0.18).

CONCLUSIONS

Preliminary data suggest that V-V ECMO without invasive ventilation may improve survival in COVID-19-related acute respiratory failure due to spontaneous PM. The study's retrospective design and limited sample size underscore the necessity for additional investigation and warrant caution.

Early initiation of physical and occupational therapy while on extracorporeal life support improves patients' functional activity

PURPOSE

Managing acute respiratory distress syndrome (ARDS) patients on venovenous extracorporeal membrane oxygenation (V-V ECMO), without sedation/neuromuscular blockade to allow physical and occupational therapy (PT/OT) participation, is untraditional. Here, we investigate the impact of early PT/OT initiation on discharge functional activity for ARDS patients managed on V-V ECMO.

METHODS

This is a retrospective review of 67 ARDS patients managed with V-V ECMO at a single academic center from February 2018 to June 2021. Data collected included patient characteristics, days of V-V ECMO support, day of PT/OT initiation, and ambulation distance and Activity Measure for Post-Acute Care (AMPAC) Six-Clicks score on day of discharge.

RESULTS

Patients with >7 days of V-V ECMO support had decreased ambulation and AMPAC scores compared to those with <7 days (70.5 vs. 162.1, p < 0.01 and 12.3 vs. 16.4, p = 0.01, respectively). PT/OT initiation within 7 days after starting V-V ECMO significantly improved ambulation and AMPAC scores (163.5 vs. 59.5, p < 0.001, and 16.6 vs. 11.8, p < 0.01, respectively). Additionally, in patients with >7 days of V-V ECMO support, those who began PT/OT within 8 days of V-V ECMO cannulation had significantly improved ambulation and AMPAC scores (151.8 vs. 44.2, p < 0.01, and 16.5 vs. 11.0, p < 0.01, respectively).

CONCLUSION

Early PT/OT initiation in severe ARDS patients managed on V-V ECMO is associated with improved patient functional activity on day of discharge. Our study further supports the use of V-V ECMO in treatment of severe ARDS without sedation/neuromuscular blockade and specifically demonstrates PT/OT should be started early following V-V ECMO cannulation.

Sedation and analgesia requirements during venovenous extracorporeal membrane oxygenation in acute respiratory distress syndrome patients

INTRODUCTION

The purpose of this study is to describe sedation and analgesia management, and identify the factors associated with increased demand for medication in acute respiratory distress syndrome (ARDS) patients receiving venovenous extracorporeal membrane oxygenation (VV-ECMO).

METHODS

This retrospective, single-center study included consecutive adult ARDS patients who received VV-ECMO for at least 24 hours from January 2018 to December 2020 in a comprehensive intensive care unit. The electronic medical records were retrospectively reviewed to collect data.

RESULTS

Forty-two adult patients meeting the inclusion criteria were included in the study. Midazolam, sufentanil, and remifentanil were main sedatives and analgesics used in the patient population. The morphine equivalents, representative of the demand for opioids, was 512.9 (IQR, 294.5, 798.2) mg/day. The midazolam equivalents, representative of benzodiazepine requirement, was 279.6 (IQR, 208.8, 384.5) mg/day. The levels of serum creatinine, total bilirubin, lactic acid, SOFA score, and APACHE Ⅱ score at cannulation were found to be associated with opiate or benzodiazepine requirements. Multiple linear regression analysis revealed a linear correlation between midazolam equivalents and morphine equivalents (p < 0.001). In addition, there was a negative linear correlation between Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score and midazolam equivalents (p = 0.024).

CONCLUSIONS

The sedation and analgesia requirements of ARDS patients receiving VV-ECMO often increase simultaneously. More large-scale studies are needed to confirm the risk factors for increased sedation and analgesia needs in patients supported on VV-ECMO.

Impact of extracorporeal membrane oxygenation on voriconazole plasma concentrations: A retrospective study

Aims: We aimed to assess the impact of extracorporeal membrane oxygenation (ECMO) on voriconazole exposure.

Methods: Adult critically ill patients with or without ECMO support receiving intravenous voriconazole therapy were included in this retrospective study conducted in a tertiary referral intensive care unit. The first therapeutic drug monitoring (TDM) results of voriconazole in ECMO patients and non-ECMO patients were collected, and the prevalence of subtherapeutic concentrations was analyzed. Multivariate analyses were performed to evaluate the effect of ECMO on voriconazole exposure.

Results: A total of 132 patients (including 66 patients with ECMO support) were enrolled and their respective first voriconazole trough concentrations (C_min) were recorded. The median C_min of the ECMO group and the non-ECMO group was 1.9 (1.4–4.4) and 4.4 (3.2–6.9) mg/L, respectively (p = 0.000), and the proportion of the two groups in subtherapeutic concentrations range (<2 mg/L) was 51.5% and 7.6%, respectively (p = 0.000). Multiple linear regression analysis of voriconazole C_min identified that the use of ECMO and coadministration of glucocorticoids were associated with significantly reduced concentrations, while increasing SOFA score and increasing daily dose were associated with significantly increased concentrations. The model accounted for 32.2% of the variability of voriconazole C_min. Furthermore, binary logistic regression demonstrated that the use of ECMO was an independent risk factor (OR = 7.78, p = 0.012) for insufficient voriconazole exposure.

Conclusion: Our findings showed that, in addition to the known drug interactions, ECMO is a significant covariable affecting voriconazole exposure. In addition, SOFA score was identified as a factor associated with increased voriconazole concentration.

[Psychological aspects during and after intensive care treatment of ARDS]

Approximately 10% of all patients requiring intensive care develop acute respiratory distress syndrome (ARDS). The COVID-19 pandemic led to an accumulation of patients with severe ARDS. The experience of this severe respiratory failure is accompanied by feelings of existential anxiety in many patients.The complexity of the challenges and stresses that the disease and its treatment pose for the ARDS patient require an early multiprofessional approach to treatment already during intensive care. Psychological approaches are suitable to support the patient as well as the relatives in coping with the disease and to minimise risks for potential subsequent stress. Despite the long-term impairments of patients who have survived ARDS and the resulting need for follow-up care, suitable multimodal follow-up care concepts and the necessary care structures are still lacking. The article presents the psychological support during and after the intensive care treatment of ARDS.

Can Cardiopulmonary Rehabilitation Facilitate Weaning of Extracorporeal Membrane Oxygenation (CaRe-ECMO)? Study Protocol for a Prospective Multidisciplinary Randomized Controlled Trial

Background: Mortality of patients suffering from critical illness has been dramatically improved with advanced technological development of extracorporeal membrane oxygenation (ECMO) therapy. However, the majority of ECMO-supported patients failed to wean from ECMO therapy. As one of several options, cardiopulmonary rehabilitation serves as effective intervention in the improvement of cardiovascular and respiratory function in various major critical illness. Nonetheless, its role in facilitating ECMO weaning has not yet been explored. The purpose of this study is to investigate the effectiveness of cardiopulmonary rehabilitation on rate of ready for ECMO weaning in ECMO-supported patients (CaRe-ECMO).

Methods: The CaRe-ECMO trial is a randomized controlled, parallel group, clinical trial. This trial will be performed in a minimum number of 366 ECMO-supported eligible patients. Patients will be randomly assigned to either: (1) the CaRe-ECMO group, which will be treated with usual care including pharmacotherapy, non-pharmacotherapy, and specific nursing for ECMO therapy and the CaRe-ECMO program; or (2) the control group, which will receive usual care only. The CaRe-ECMO program consists of protocolized positioning, passive range of motion (PROM) training, neuromuscular electrical stimulation (NMES), surface electrical phrenic nerve stimulation (SEPNS), and pulmonary rehabilitation. The primary outcome of the CaRe-ECMO trial is the rate of ready for ECMO weaning at CaRe-ECMO day 7 (refers to 7 days after the CaRe-ECMO program initiation). Secondary outcomes include rate of ECMO and mechanical ventilation weaning, total length in day of ready for ECMO weaning, ECMO weaning and mechanical ventilation, all-cause mortality, rate of major post-ECMO complications, ECMO unit length of stay (LOS) and hospital LOS, total cost for hospitalization, cerebral performance category (CPC), activities of daily living (ADL), and health-related quality of life (HRQoL).

Discussion: The CaRe-ECMO is designed to answer the question “whether cardiopulmonary rehabilitation can facilitate weaning of ECMO (CaRe-ECMO).” Should the implementation of the CaRe-ECMO program result in superior primary and secondary outcomes as compared to the controls, specifically the add-on effects of cardiopulmonary rehabilitation to the routine ECMO practice for facilitating successful weaning, the CaRe-ECMO trial will offer an innovative treatment option for ECMO-supported patients and meaningfully impact on the standard care in ECMO therapy.

Clinical Trial Registration:ClinicalTrials.gov, identifier: NCT05035797.

An Ovine Model of Awake Veno-Arterial Extracorporeal Membrane Oxygenation

Background: Large animal models are developed to help understand physiology and explore clinical translational significance in the continuous development of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) technology. The purpose of this study was to investigate the establishment methods and management strategies in an ovine model of VA-ECMO. Methods: Seven sheep underwent VA-ECMO support for 7 days by cannulation via the right jugular vein and artery. The animals were transferred into the monitoring cages after surgery and were kept awake after anesthesia recovery. The hydraulic parameters of ECMO, basic hemodynamics, mental state, and fed state of sheep were observed in real time. Blood gas analysis and activated clotting time (ACT) were tested every 6 h, while the complete blood count, blood chemistry, and coagulation tests were monitored every day. Sheep were euthanized after 7 days. Necropsy was performed and the main organs were removed for histopathological evaluation. Results: Five sheep survived and successfully weaned from ECMO. Two sheep died within 24-48 h of ECMO support. One animal died of fungal pneumonia caused by reflux aspiration, and the other died of hemorrhagic shock caused by bleeding at the left jugular artery cannulation site used for hemodynamic monitoring. During the experiment, the hemodynamics of the five sheep were stable. The animals stayed awake and freely ate hay and feed pellets and drank water. With no need for additional nutrition support or transfusion, the hemoglobin concentration and platelet count were in the normal reference range. The ECMO flow remained stable and the oxygenation performance of the oxygenator was satisfactory. No major adverse pathological injury occurred. Conclusions: The perioperative management strategies and animal care are the key points of the VA-ECMO model in conscious sheep. This model could be a platform for further research of disease animal models, pathophysiology exploration, and new equipment verification.