Modalities of Exercise Training in Patients with Extracorporeal Membrane Oxygenation Support

Use of Extracorporeal Membrane Oxygenation for Patients with Coronavirus Disease 2019 Infection

The coronavirus disease 2019 (COVID-19) pandemic was a cataclysmic event that infected over 772 million and killed over 6.9 million people worldwide. The pandemic pushed hospitals and society to their limits and resulted in incredibly severe respiratory disease in millions of people. This severe respiratory disease often necessitated maximum medical therapy, including the use of extracorporeal membrane oxygenation. While our understanding of COVID-19 and its treatment continue to evolve, we review the current evidence to guide the care of patients with severe COVID-19 infection.

Safety and Feasibility of Neuromuscular Electrical Stimulation in Patients with Extracorporeal Membrane Oxygenation

Background/Objectives: The aim of this study was to investigate the feasibility and safety of neuromuscular electrical stimulation (NMES) in patients on extracorporeal membrane oxygenation (ECMO) and thoroughly assess any potential adverse events. Methods: We conducted a prospective observational study assessing safety and feasibility, including 16 ICU patients on ECMO support who were admitted to the cardiac surgery ICU from January 2022 to December 2023. The majority of patients were females (63%) on veno-arterial (VA)-ECMO (81%), while the main cause was cardiogenic shock (81%) compared to respiratory failure. Patients underwent a 45 min NMES session while on ECMO support that included a warm-up phase of 5 min, a main phase of 35 min, and a recovery phase of 5 min. NMES was implemented on vastus lateralis, vastus medialis, gastrocnemius, and peroneus longus muscles of both lower extremities. Two stimulators delivered biphasic, symmetric impulses of 75 Hz, with a 400 μsec pulse duration, 5 sec on (1.6 sec ramp up and 0.8 sec ramp down) and 21 sec off. The intensity levels aimed to cause visible contractions and be well tolerated. Primary outcomes of this study were feasibility and safety, evaluated by whether NMES sessions were successfully achieved, and by any adverse events and complications. Secondary outcomes included indices of rhabdomyolysis from biochemical blood tests 24 h after the application of NMES. Results: All patients successfully completed their NMES session, with no adverse events or complications. The majority of patients achieved type 4 and 5 qualities of muscle contraction. Conclusions: NMES is a safe and feasible exercise methodology for patients supported with ECMO.

Latest updates on structure and recommendations of cardiac rehabilitation programs in chronic heart failure

Chronic heart failure (HF) is a clinical syndrome with high morbidity and mortality worldwide. Cardiac rehabilitation (CR) is a medically supervised program designed to maintain or improve cardiovascular health of people living with HF, recommended by both American and European guidelines. A CR program consists of a multispecialty group including physicians, nurses, physiotherapists, trainers, nutritionists, and psychologists with the common purpose of improving functional capacity and quality of life of chronic HF patients. Physical activity, lifestyle, and psychological support are core components of a successful CR program. CR has been shown to be beneficial in all ejection fraction categories in HF and most patients, who are stable under medication, are capable of participating. An individualized exercise prescription should be developed on the basis of a baseline evaluation in all patients. The main modalities of exercise training are aerobic exercise and muscle strength training of different intensity and frequency. It is important to set the appropriate clinical outcomes from the beginning, in order to assess the effectiveness of a CR program. There are still significant limitations that prevent patients from participating in these programs and need to be solved. A significant limitation is the generally low quality of research in CR and the presence of negative trials, such as the rehabilitation after myocardial infarction trial, where comprehensive rehabilitation following myocardial infraction had no important effect on mortality, morbidity, risk factors, or health-related quality of life or activity. In the present editorial, we present all the updated knowledge and recommendations in CR programs.

Survival and Long-Term Functional Status of COVID-19 Patients Requiring Prolonged Extracorporeal Membrane Oxygenation Support

Rationale: Severe cases of acute respiratory distress syndrome (ARDS) may require prolonged (>28 d) extracorporeal membrane oxygenation (ECMO). In nonresolving disease, recovery is uncertain, and lung transplant may be proposed. Objectives: This study aims to identify the variables influencing survival and to describe the functional status of these patients at 6 months. Methods: This was a retrospective, multicenter, observational cohort study including patients requiring ECMO support for coronavirus disease (COVID-19)-related ARDS for >28 days. Multivariate analysis was performed using Cox regression in preselected variables and in least absolute shrinkage and selection operator selected variables. In a post hoc analysis to account for confounders and differences in awake strategy use by centers, treatment effects of the awake strategy were estimated using an augmented inverse probability weighting estimator with robust standard errors clustered by center. Results: Between March 15, 2020 and March 15, 2021, 120 patients required ECMO for >28 days. Sixty-four patients (53.3%) survived decannulation, 62 (51.7%) were alive at hospital discharge, and 61 (50.8%) were alive at 6-month follow-up. In the multivariate analysis, age (1.09; 95% confidence interval [CI], 1.03-1.15; P = 0.002) and an awake ECMO strategy (defined as the patient being awake, cooperative, and performing rehabilitation and physiotherapy with or without invasive mechanical ventilation at any time during the extracorporeal support) (0.14; 95% CI, 0.03-0.47; P = 0.003) were found to be predictors of hospital survival. At 6 months, 51 (42.5%) patients were at home, 42 (84.3%) of them without oxygen therapy. A cutoff point of 47 ECMO days had a 100% (95% CI, 76.8-100%) sensitivity and 60% (95% CI, 44.3-73.6%) specificity for oxygen therapy at 6 months, with 100% specificity being found in 97 days. Conclusions: Patients with COVID-19 who require ECMO for >28 days can survive with nonlimiting lung impairment. Age and an awake ECMO strategy may be associated with survival. Longer duration of support correlates with need for oxygen therapy at 6 months.

Cardiac rehabilitation after cardiac surgery: An important underutilized treatment strategy

Physical inactivity remains in high levels after cardiac surgery, reaching up to 50%. Patients present a significant loss of functional capacity, with prominent muscle weakness after cardiac surgery due to anesthesia, surgical incision, duration of cardiopulmonary bypass, and mechanical ventilation that affects their quality of life. These complications, along with pulmonary complications after surgery, lead to extended intensive care unit (ICU) and hospital length of stay and significant mortality rates. Despite the well-known beneficial effects of cardiac rehabilitation, this treatment strategy still remains broadly underutilized in patients after cardiac surgery. Prehabilitation and ICU early mobilization have been both showed to be valid methods to improve exercise tolerance and muscle strength. Early mobilization should be adjusted to each patient's functional capacity with progressive exercise training, from passive mobilization to more active range of motion and resistance exercises. Cardiopulmonary exercise testing remains the gold standard for exercise capacity assessment and optimal prescription of aerobic exercise intensity. During the last decade, recent advances in healthcare technology have changed cardiac rehabilitation perspectives, leading to the future of cardiac rehabilitation. By incorporating artificial intelligence, simulation, telemedicine and virtual cardiac rehabilitation, cardiac surgery patients may improve adherence and compliance, targeting to reduced hospital readmissions and decreased healthcare costs.

Advanced Heart Failure: Therapeutic Options and Challenges in the Evolving Field of Left Ventricular Assist Devices

Heart Failure is a chronic and progressively deteriorating syndrome that has reached epidemic proportions worldwide. Improved outcomes have been achieved with novel drugs and devices. However, the number of patients refractory to conventional medical therapy is growing. These advanced heart failure patients suffer from severe symptoms and frequent hospitalizations and have a dismal prognosis, with a significant socioeconomic burden in health care systems. Patients in this group may be eligible for advanced heart failure therapies, including heart transplantation and chronic mechanical circulatory support with left ventricular assist devices (LVADs). Heart transplantation remains the treatment of choice for eligible candidates, but the number of transplants worldwide has reached a plateau and is limited by the shortage of donor organs and prolonged wait times. Therefore, LVADs have emerged as an effective and durable form of therapy, and they are currently being used as a bridge to heart transplant, destination lifetime therapy, and cardiac recovery in selected patients. Although this field is evolving rapidly, LVADs are not free of complications, making appropriate patient selection and management by experienced centers imperative for successful therapy. Here, we review current LVAD technology, indications for durable MCS therapy, and strategies for timely referral to advanced heart failure centers before irreversible end-organ abnormalities.

Safety and effectiveness of neuromuscular electrical stimulation in cardiac surgery: A systematic review

BACKGROUND

Lack of mobilization and prolonged stay in the intensive care unit (ICU) are major factors resulting in the development of ICU-acquired muscle weakness (ICUAW). ICUAW is a type of skeletal muscle dysfunction and a common complication of patients after cardiac surgery, and may be a risk factor for prolonged duration of mechanical ventilation, associated with a higher risk of readmission and higher mortality. Early mobilization in the ICU after cardiac surgery has been found to be low with a significant trend to increase over ICU stay and is also associated with a reduced duration of mechanical ventilation and ICU length of stay. Neuromuscular electrical stimulation (NMES) is an alternative modality of exercise in patients with muscle weakness. A major advantage of NMES is that it can be applied even in sedated patients in the ICU, a fact that might enhance early mobilization in these patients.

AIM

To evaluate safety, feasibility and effectiveness of NMES on functional capacity and muscle strength in patients before and after cardiac surgery.

METHODS

We performed a search on Pubmed, Physiotherapy Evidence Database (PEDro), Embase and CINAHL databases, selecting papers published between December 2012 and April 2023 and identified published randomized controlled trials (RCTs) that included implementation of NMES in patients before after cardiac surgery. RCTs were assessed for methodological rigor and risk of bias via the PEDro. The primary outcomes were safety and functional capacity and the secondary outcomes were muscle strength and function.

RESULTS

Ten studies were included in our systematic review, resulting in 703 participants. Almost half of them performed NMES and the other half were included in the control group, treated with usual care. Nine studies investigated patients after cardiac surgery and 1 study before cardiac surgery. Functional capacity was assessed in 8 studies via 6MWT or other indices, and improved only in 1 study before and in 1 after cardiac surgery. Nine studies explored the effects of NMES on muscle strength and function and, most of them, found increase of muscle strength and improvement in muscle function after NMES. NMES was safe in all studies without any significant complication.

CONCLUSION

NMES is safe, feasible and has beneficial effects on muscle strength and function in patients after cardiac surgery, but has no significant effect on functional capacity.

Dual lumen cannulation and mobilization of patients with venovenous extracorporeal membrane oxygenation

BACKGROUND

Mobilization is important in longer courses in intensive care unit (ICU), typical for patients requiring venovenous extracorporeal membrane oxygenation (V-V ECMO). For patients supported with ECMO, especially out-of-bed mobilizations improve outcome. We hypothesized that utilization of a dual lumen cannula (DLC) for V-V ECMO would facilitate out-of-bed mobilization compared to single lumen cannulas (SLC).

METHODS

Retrospective single center registry study including all V-V ECMO patients cannulated between 10/2010 and 05/2021 for respiratory failure.

RESULTS

The registry included 355 V-V ECMO patients (median age 55.6 years, 31.8% female, 27.3% with preexisting pulmonary disease), 289/355 (81.4%) primary cannulated with DLC, and 66/355 (18.6%) using SLC. Both groups had similar pre-ECMO characteristics. The runtime of the first ECMO cannula was significantly longer in DLC compared to SLC (169 vs. 115 h, p = 0.015). The frequency of prone positioning during V-V ECMO was similar in both groups (38.4 vs. 34.8%, p = 0.673). There was no difference in in-bed mobilization (41.2 vs. 36.4%, for DLC and SLC, respectively, p = 0.491). Patients with DLC were more often mobilized out-of-bed (25.6 vs. 12.1%, OR 2.495 [95% CI 1.150 to 5.268], for DLC and SLC, respectively, p = 0.023). Hospital survival was similar in both groups (46.4 vs. 39.4%, for DLC and SLC, respectively, p = 0.339).

CONCLUSION

Patients cannulated with a dual lumen cannula for V-V ECMO support were significantly more often mobilized out-of-bed. Since mobilization is important in prolonged ICU courses typical for ECMO patients, this might be an important benefit. Other benefits of DLC were the longer runtime of the initial cannula set and fewer suction events.

Physical Therapy for Adults with Heart Failure

Heart failure (HF) is a complex clinical syndrome caused by structural and/or functional abnormalities that results in significant disease burdens not only to the patients and their families but also to the society. Common symptoms/signs of HF include dyspnea, fatigue, and exercise intolerance, which significantly reduce the quality of life of individuals. Since the coronavirus disease 2019 (COVID-19) pandemic in 2019, it has been found that individuals with cardiovascular disease are more vulnerable to COVID-19-related cardiac sequelae including HF. In this article, we review the updated diagnosis, classifications, and interventional guidelines of HF. We also discuss the link between COVID-19 and HF. The latest evidence about physical therapy for patients with HF in both the stable chronic phase and acute cardiac decompensation phase is reviewed. Physical therapy for HF patients with circulatory support devices is also described.

Minimally Invasive Central Cannulation for Extracorporeal Life Support: The Uniportal and Subxiphoid Approach

OBJECTIVE

Extracorporeal life support (ECLS) for circulatory and/or respiratory failure is improving. Currently, invasive sternotomies or rib-spreading thoracotomies are used for central cannulation of the heart and great vessels. Although peripheral cannulation of the extremities is often used, this approach may result in immobility and unintentional dislodgement. Less invasive methods for central cannulation are needed to achieve long-term ECLS. The objective of this study was to develop 2 different minimally invasive approaches for central thoracic cannulation.

METHODS

Porcine hearts were positioned in a plastic thoracic model. An endoscopic camera and multiple endoscopic instruments were used. Both access points, uniportal (lateral) and subxiphoidal, were simulatively investigated. A novel cannulation method using purse string sutures, a custom-made endoscopic puncture tool, guidewires, and dilator-assisted cannulas was developed. Simulations were tested in a closed circuit regarding leak tightness.

RESULTS

The uniportal approach allowed a cannulation of the aorta, inferior vena cava, right atrium, and main pulmonary artery. Cannulation of the right branches of the pulmonary artery and vein was also possible. From the subxiphoid approach, cannulation of the aorta, main pulmonary artery, and both atria were possible. Subsequent evaluation and leakage tests revealed no damage to the surrounding structures and tightly sealed cannulation sites. The uniportal approach was also successfully performed in a human cadaver to connect the aorta and right atrium with cannulas from the subxiphoidal space.

CONCLUSIONS

Both uniportal and subxiphoid central cannulation of potential sites for ECLS were feasible. This study encourages further investigation and potential clinical translation of minimally invasive central organ support.