Awake ECMO on the move to lung transplantation: serial monitoring of physical condition

Mechanical ventilation during extracorporeal membrane oxygenation support - New trends and continuing challenges

BACKGROUND

The impact of mechanical ventilation on the survival of patients supported with veno-venous extracorporeal membrane oxygenation (V-V ECMO) due to severe acute respiratory distress syndrome (ARDS) remains still a focus of research.

METHODS

Recent guidelines, randomized trials, and registry data underscore the importance of lung-protective ventilation during respiratory and cardiac support on ECMO.

RESULTS

This approach includes decreasing mechanical power delivery by reducing tidal volume and driving pressure as much as possible, using low or very low respiratory rate, and a personalized approach to positive-end expiratory pressure (PEEP) setting. Notably, the use of ECMO in awake and spontaneously breathing patients is increasing, especially as a bridging strategy to lung transplantation. During respiratory support in V-V ECMO, native lung function is of highest importance and adjustments of blood flow on ECMO, or ventilator settings significantly impact the gas exchange. These interactions are more complex in veno-arterial (V-A) ECMO configuration and cardiac support. The fraction on delivered oxygen in the sweep gas and sweep gas flow rate, blood flow per minute, and oxygenator efficiency have an impact on gas exchange on device side. On the patient side, native cardiac output, native lung function, carbon dioxide production (VCO2), and oxygen consumption (VO2) play a role. Avoiding pulmonary oedema includes left ventricle (LV) distension monitoring and prevention, pulse pressure >10 mm Hg and aortic valve opening assessment, higher PEEP adjustment, use of vasodilators, ECMO flow adjustment according to the ejection fraction, moderate use of inotropes, diuretics, or venting strategies as indicated and according to local expertise and resources.

CONCLUSION

Understanding the physiological principles of gas exchange during cardiac support on femoro-femoral V-A ECMO configuration and the interactions with native gas exchange and haemodynamics are essential for the safe applications of these techniques in clinical practice. Proning during ECMO remains to be discussed until further data is available from prospective, randomized trials implementing individualized PEEP titration during proning.

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.

Standardized approach for extubation during extracorporeal membrane oxygenation in severe acute respiratory distress syndrome: a prospective observational study

BACKGROUND

Extubation during extracorporeal oxygenation (ECMO) in severe acute respiratory distress syndrome (ARDS) has not been well studied. Despite the potential benefits of this strategy, weaning from ECMO before liberation from invasive mechanical ventilation remains the most frequent approach. Our aim was to evaluate the safety and feasibility of a standardized approach for extubation during ECMO in patients with severe ARDS.

RESULTS

We conducted a prospective observational study to assess the safety and feasibility of a standardized approach for extubation during ECMO in severe ARDS among 254 adult patients across 4 intensive care units (ICU) from 2 tertiary ECMO centers over 6 years. This consisted of a daily assessment of clinical and gas exchange criteria based on an Extracorporeal Life Support Organization guideline, with extubation during ECMO after validation by a dedicated intensive care medicine specialist. Fifty-four (21%) patients were extubated during ECMO, 167 (66%) did not reach the clinical criteria, and in 33 (13%) patients, gas exchange precluded extubation during ECMO. At ECMO initiation, there were fewer extrapulmonary organ dysfunctions (lower SOFA score [OR, 0.88; 95% CI, 0.79-0.98; P = .02] with similar PaO2/FiO2) when compared with patients not extubated during ECMO. Extubation during ECMO associated with shorter duration of invasive mechanical ventilation (7 (4-18) vs. 32 (18-54) days; P < .01) and of ECMO (12 (7-25) vs. 19 (10-41) days; P = .01). This was accompanied by a lower incidence of hemorrhagic shock (2 vs. 11%; P = .05), but more cannula-associated deep vein thrombosis (49 vs. 31%; P = .02) and failed extubation (20 vs. 6%; P < .01). There were no increased major adverse events. Extubation during ECMO is associated with a lower risk of all-cause death, independently of measured confounding (adjusted logistic regression OR 0.23; 95% confidence interval 0.08-0.69, P = .008).

CONCLUSIONS

A standardized approach was safe and feasible allowing extubation during ECMO in 21% of patients with severe ARDS, selecting patients who will have a shorter duration of invasive mechanical ventilation, ECMO course, and ICU stay, as well as fewer infectious complications, and high hospital survival.

Construction of Sports Nutrition Dynamic Intervention Mechanism Based on the Improvement of College Students’ Physical Health

Exercise can improve people's physical health and strengthen their body bones. But the physique of college students is generally too poor. The enhancement of College Students' physique cannot be completed in a day. This study aims to explore the best sports nutrition intervention scheme for strengthening college students' physique from the construction of sports nutrition dynamic intervention mechanism, so as to provide theoretical reference for public physical education teaching and students' independent exercise. In this study, 100 full-time associate students in our university were selected as the research objects. Before the experiment, the subjects' body shape, body function, and physical quality were tested. Based on the random mathematical method, the full-time associate students were randomly divided into four groups: control group, exercise intervention group, nutrition intervention group, and sports nutrition intervention group, with 25 people in each group. After the experiment, the body shape, body function, and physical quality of the four groups were tested. The results show that exercise and nutrition intervention have little effect on college students' height, but have great influence on body mass index, vital capacity and 800 meter running. Especially after the experiment, the vital capacity of the exercise group and the sports nutrition group increased by nearly 250 ml and 500 ml, respectively, and the 800 m running time increased by nearly 10 s and 18 s, respectively. Strengthening exercise and increasing nutritional intake can effectively improve the institutional health of college students.

Rehabilitation of adult patients on extracorporeal membrane oxygenation: A scoping review

OBJECTIVES

The objective of this study was to conduct a scoping review to comprehensively map the breadth of literature related to the rehabilitation of adult patients whilst on extracorporeal membrane oxygenation (ECMO) and identify gaps and areas for future research.

REVIEW METHOD USED

This review was conducted using recommended frameworks for methods and reporting including the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews.

DATE SOURCES

We searched seven databases from inception to June 2021 and included all study designs and grey literature.

REVIEW METHODS

Eligibility screening was completed by two independent reviewers according to inclusion and exclusion criteria, with any disagreement resolved by consensus or with consultation with a third reviewer. Two independent reviewers extracted data related to intervention characteristics, patient outcomes, feasibility, safety, hospital outcomes, and mortality using a custom-designed piloted form.

RESULTS

Of 8507 records, 185 original studies met inclusion criteria, with the majority being small retrospective studies. Rehabilitation was more commonly reported in patients on veno-venous rather than veno-arterial ECMO. Ambulation was the most commonly reported intervention (51% of studies). Critical gaps were identified including incomplete reporting of the intervention along with heterogeneity in the type and timing of outcome measures. Less than 50% of patients met eligibility criteria to participate, but screening for eligibility was infrequently reported (9% of studies). Delivery of rehabilitation during ECMO may be facilitated by an expert multidisciplinary team, along with a strategy that targets low sedation levels and an upper body cannulation approach.

CONCLUSIONS

Rehabilitation during ECMO is an emerging area of research and mostly consisted of small retrospective single-centre studies. Future research requires more robust methodological designs that include comprehensive screening of potential candidates with reporting of eligibility, more detailed descriptions of the rehabilitation interventions, inclusion of a core outcome set with defined measurement instruments, and consistent timing of outcome measurement.

Twelve years of circulatory extracorporeal life support at the University Medical Centre Utrecht

Introduction

Circulatory extracorporeal life support (ECLS) has been performed at the University Medical Centre Utrecht for 12 years. During this time, case mix, indications, ECLS set-ups and outcomes seem to have substantially changed. We set out to describe these characteristics and their evolution over time.

Methods

All patients receiving circulatory ECLS between 2007 and 2018 were retrospectively identified and divided into six groups according to a 2-year period of time corresponding to the date of ECLS initiation. General characteristics plus data pertaining to comorbidities, indications and technical details of ECLS commencement as well as in-hospital, 30-day, 1‑year and overall mortality were collected. Temporal trends in these characteristics were examined.

Results

A total of 347 circulatory ECLS runs were performed in 289 patients. The number of patients and ECLS runs increased from 8 till a maximum of 40 runs a year. The distribution of circulatory ECLS indications shifted from predominantly postcardiotomy to a wider set of indications. The proportion of peripheral insertions with or without application of left ventricular unloading techniques substantially increased, while in-hospital, 30-day, 1‑year and overall mortality decreased over time.

Conclusion

Circulatory ECLS was increasingly applied at the University Medical Centre Utrecht. Over time, indications as well as treatment goals broadened, and cannulation techniques shifted from central to mainly peripheral approaches. Meanwhile, weaning success increased and mortality rates diminished.

Supplementary Information

The online version of this article (10.1007/s12471-021-01552-z) contains supplementary material, which is available to authorized users.

Artificial lungs--Where are we going with the lung replacement therapy?

Lung transplantation may be a final destination therapy in lung failure, but limited donor organ availability creates a need for alternative management, including artificial lung technology. This invited review discusses ongoing developments and future research pathways for respiratory assist devices and tissue engineering to treat advanced and refractory lung disease. An overview is also given on the aftermath of the coronavirus disease 2019 pandemic and lessons learned as the world comes out of this situation. The first order of business in the future of lung support is solving the problems with existing mechanical devices. Interestingly, challenges identified during the early days of development persist today. These challenges include device-related infection, bleeding, thrombosis, cost, and patient quality of life. The main approaches of the future directions are to repair, restore, replace, or regenerate the lungs. Engineering improvements to hollow fiber membrane gas exchangers are enabling longer term wearable systems and can be used to bridge lung failure patients to transplantation. Progress in the development of microchannel-based devices has provided the concept of biomimetic devices that may even enable intracorporeal implantation. Tissue engineering and cell-based technologies have provided the concept of bioartificial lungs with properties similar to the native organ. Recent progress in artificial lung technologies includes continued advances in both engineering and biology. The final goal is to achieve a truly implantable and durable artificial lung that is applicable to destination therapy.

Extubation and Noninvasive Ventilation of Patients Supported by Extracorporeal Life Support for Cardiogenic Shock: A Single-Center Retrospective Observational Cohort Study

Background:

Temporary extracorporeal life support (ECLS) by venoarterial extracorporeal membrane oxygenation is an emerging therapy for patients with severe, ongoing cardiogenic shock. After stabilization of the hemodynamic status and end-organ function, sedation weaning, extubation, and noninvasive ventilation (NIV) can be attempted. The goal of this study was to analyze the feasibility of extubation and NIV during versus after ECLS for cardiogenic shock.

Methods:

Single-center retrospective observational study of 132 patients undergoing ECLS due to severe cardiogenic shock between January 2015 and December 2016 at a tertiary care university hospital.

Results:

Patients received ECLS due to acute myocardial infarction (20.6%), ongoing cardiogenic shock (15.2%), postoperative low-cardiac-output syndrome (24.2%), and extracorporeal cardiopulmonary resuscitation (40.2%). Overall, intensive care unit survival was 44.7%. Sixty-nine (52.3%) patients could never be extubated. Forty-three (32.6%) were extubated while on ECLS support (group 1) and 20 (15.1%) were extubated after weaning from ECLS (group 2). Patients extubated during ECLS had a significantly shorter total time on ventilator (P = .003, mean difference: −284 hours [95% confidence limits: −83 to −484]) and more invasive ventilation free days (P = .0018; mean difference 8 days [95%CL: 2-14]). Mortality and NIV failure rates were similar between groups.

Conclusions:

Extubation and NIV are feasible in patients who stabilize during ECLS therapy. Further studies need to address whether extubation has the potential to improve patients outcome or if the feasibility to extubate is a surrogate for disease severeness.