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.

An evolutionary epigenetic clock in plants

Molecular clocks are the basis for dating the divergence between lineages over macroevolutionary timescales (~105 to 108 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes display a clocklike behavior. This "epimutation clock" is orders of magnitude faster than DNA-based clocks and enables phylogenetic explorations on a scale of years to centuries. We show experimentally that epimutation clocks recapitulate known topologies and branching times of intraspecies phylogenetic trees in the self-fertilizing plant Arabidopsis thaliana and the clonal seagrass Zostera marina, which represent two major modes of plant reproduction. This discovery will open new possibilities for high-resolution temporal studies of plant biodiversity.

An evolutionary epigenetic clock in plants

Molecular clocks are the basis for dating the divergence between lineages over macro-evolutionary timescales (~10 5 -10 8 years). However, classical DNA-based clocks tick too slowly to inform us about the recent past. Here, we demonstrate that stochastic DNA methylation changes at a subset of cytosines in plant genomes possess a clock-like behavior. This 'epimutation-clock' is orders of magnitude faster than DNA-based clocks and enables phylogenetic explorations on a scale of years to centuries. We show experimentally that epimutation-clocks recapitulate known topologies and branching times of intra-species phylogenetic trees in the selfing plant A. thaliana and the clonal seagrass Z. marina , which represent two major modes of plant reproduction. This discovery will open new possibilities for high-resolution temporal studies of plant biodiversity.

Early Physical Therapist Interventions for Patients With COVID-19 in the Acute Care Hospital: A Case Report Series

OBJECTIVE

The aim of this case series was to describe the experience of Swiss physical therapists in the treatment of patients with COVID-19 during their acute care hospital stay and to discuss challenges and potential strategies in the clinical management of these patients.

METHODS

We report 11 cases of patients with COVID-19 from 5 Swiss hospitals that illustrate the various indications for physical therapy, clinical challenges, potential treatment methods, and short-term response to treatment.

RESULTS

Physical therapists actively treated patients with COVID-19 on wards and in the intensive care unit. Interventions ranged from patient education, to prone positioning, to early mobilization and respiratory therapy. Patients were often unstable with quick exacerbation of symptoms and a slow and fluctuant recovery. Additionally, many patients who were critically ill developed severe weakness, postextubation dysphagia, weaning failure, or presented with anxiety or delirium. In this setting, physical therapy was challenging and required specialized and individualized therapeutic strategies. Most patients adopted the proposed treatment strategies, and lung function and physical strength improved over time.

CONCLUSION

Physical therapists clearly have a role in the COVID-19 pandemic. Based on our experience in Switzerland, we recommend that physical therapists routinely screen and assess patients for respiratory symptoms and exercise tolerance on acute wards. Treatment of patients who are critically ill should start as soon as possible to limit further sequelae. More research is needed for awake prone positioning and early breathing exercises as well as post-COVID rehabilitation.

IMPACT

To date, there are few data on the physical therapist management of patients with COVID-19. This article is among the first to describe the role of physical therapists in the complex pandemic environment and to describe the potential treatment strategies for countering the various challenges in the treatment of these patients.