Introduction: Coronavirus disease 2019 (COVID-19) has rapidly become a global pandemic, but little is known about its potential impact on patients with myasthenia gravis (MG).

Methods: We studied the clinical course of COVID-19 in five hospitalized patients with autoimmune MG (four with acetylcholine receptor antibodies, one with muscle-specific tyrosine kinase antibodies) between April 1, 2020-April 30-2020.

Results: Two patients required intubation for hypoxemic respiratory failure, whereas one required significant supplemental oxygen. One patient with previously stable MG had myasthenic exacerbation. One patient treated with tocilizumab for COVID-19 was successfully extubated. Two patients were treated for MG with intravenous immunoglobulin without thromboembolic complications.

Discussion: Our findings suggest that the clinical course and outcomes in patients with MG and COVID-19 are highly variable. Further large studies are needed to define best practices and determinants of outcomes in this unique population.

Keywords: COVID-19; immunosuppression; myasthenia gravis; neuroimmunology; neuromuscular disorders.

Objective: To determine the prevalence, risk factors, and outcomes of critical illness neuromuscular abnormalities (CINMA).

Design: Systematic review.

Data sources and study selection: MEDLINE, EMBASE, CINAHL, and the Cochrane Library were searched for reports on adult ICU patients who were evaluated for CINMA clinically and electrophysiologically. Studies were included if they contained sufficient data to quantify the association between CINMA and relevant exposures and/or outcome variables.

Measurements and results: CINMA was diagnosed in 655 of 1421 [46% (95% confidence interval 43-49%)] adult ICU patients enrolled in 24 studies, all with inclusion criteria of sepsis, multi-organ failure, or prolonged mechanical ventilation. Diagnostic criteria for CINMA were not uniform, and few reports unequivocally differentiated between polyneuropathy, myopathy, and mixed types of CINMA. The risk of CINMA was associated with hyperglycemia (and inversely associated with tight glycemic control), the systemic inflammatory response syndrome, sepsis, multiple organ dysfunction, renal replacement therapy, and catecholamine administration. Across studies, there was no consistent relationship between CINMA and patient age, gender, severity of illness, or use of glucocorticoids, neuromuscular blockers, aminoglycosides, or midazolam. Unadjusted mortality was not increased in the majority of patients with CINMA, but mechanical ventilation and ICU and hospital stay were prolonged.

Conclusions: The risk of CINMA is nearly 50% in ICU patients with sepsis, multi-organ failure, or protracted mechanical ventilation. The association of CINMA with frequently cited CINMA risk factors (glucocorticoids, neuromuscular blockers) and with short-term survival is uncertain. Available data indicate glycemic control as a potential strategy to decrease CINMA risk.

Context: Although electrophysiologic and histologic neuromuscular abnormalities are common in intensive care unit (ICU) patients, the clinical incidence of ICU-acquired neuromuscular disorders in patients recovering from severe illness remains unknown.

Objectives: To assess the clinical incidence, risk factors, and outcomes of ICU-acquired paresis (ICUAP) during recovery from critical illness in the ICU and to determine the electrophysiologic and histologic patterns in patients with ICUAP.

Design: Prospective cohort study conducted from March 1999 to June 2000.

Setting: Three medical and 2 surgical ICUs in 4 hospitals in France.

Participants: All consecutive ICU patients without preexisting neuromuscular disease who underwent mechanical ventilation for 7 or more days were screened daily for awakening. The first day a patient was considered awake was day 1. Patients with severe muscle weakness on day 7 were considered to have ICUAP.

Main outcome measures: Incidence and duration of ICUAP, risk factors for ICUAP, and comparative duration of mechanical ventilation between ICUAP and control patients.

Results: Among the 95 patients who achieved satisfactory awakening, the incidence of ICUAP was 25.3% (95% confidence interval [CI], 16.9%-35.2%). All ICUAP patients had a sensorimotor axonopathy, and all patients who underwent a muscle biopsy had specific muscle involvement not related to nerve involvement. The median duration of ICUAP after day 1 was 21 days. Mean (SD) duration of mechanical ventilation after day 1 was significantly longer in patients with ICUAP compared with those without (18.2 [36.3] vs 7.6 [19.2] days; P =.03). Independent predictors of ICUAP were female sex (odds ratio [OR], 4.66; 95% CI, 1.19-18.30), the number of days with dysfunction of 2 or more organs (OR, 1.28; 95% CI, 1.11-1.49), duration of mechanical ventilation (OR, 1.10; 95% CI, 1.00-1.22), and administration of corticosteroids (OR, 14.90; 95% CI, 3.20-69.80) before day 1.

Conclusions: Identified using simple bedside clinical criteria, ICUAP was frequent during recovery from critical illness and was associated with a prolonged duration of mechanical ventilation. Our findings suggest an important role of corticosteroids in the development of ICUAP.