Myasthenic crisis

Abstract

We retrospectively reviewed the hospital records of 53 patients admitted for 73 episodes of myasthenic crisis at Columbia-Presbyterian Medical Center over a period of 12 years, from 1983 to 1994. Median age at the onset of first crisis was 55 (range, 20 to 82), the ratio of women to men was 2:1, and the median interval from onset of symptoms to first crisis was 8 months. Infection (usually pneumonia or upper respiratory infection) was the most common precipitating factor (38%), followed by no obvious cause (30%) and aspiration (10%). Twenty-five percent of patients were extubated at 7 days, 50% at 13 days, and 75% at 31 days; the longest crisis exceeded 5 months. Using survival analysis and backward stepwise Cox regression, we identified three independent predictors of prolonged intubation: (1) pre-intubation serum bicarbonate > or = 30 mg/dl (p = 0.0004, relative hazard 4.5), (2) peak vital capacity day 1 to 6 post-intubation < 25 ml/kg (p = 0.001, relative hazard 2.9), and (3) age > 50 (p = 0.01, relative hazard 2.4). The proportion of patients intubated longer than 2 weeks was 0% among those with no risk factors, 21% with one risk factor, 46% with two risk factors, and 88% with three risk factors (p = 0.0004). Complications independently associated with prolonged intubation included atelectasis (p = 0.002), anemia treated with transfusion (p = 0.03), Clostridium difficile infection (p = 0.01), and congestive heart failure (p = 0.03). Three episodes of crisis were fatal, for a mortality rate of 4% (3/73); four additional patients died after extubation. All seven deaths were due to overwhelming medical comorbidity. Over half of those who survived were functionally dependent (home or institutionalized) at discharge. In addition to prospective controlled studies of immunotherapies, the prevention and treatment of medical complications offers the best opportunity for further improving the outcome of myasthenic crisis.

Myasthenic crisis: report of 24 cases

“…In that study, the female/male ratio was roughly 1.5:1 3 . The majority of our patients who developed MC were female, results similar to those of the Columbia-Presbiterian series 6 .…”

“…Myasthenic crisis is a medical emergency defined by respiratory failure requiring mechanical ventilation, occurring in 15-20% of MG patients 6 . Among our patients the incidence of MC was 12.76% and it was more frequent in the first 2 years of disease.…”

“…A precipitating factor could not be elicited in most of our cases. Whenever a precipitating factor can be elicited, infections are the leading cause of MC as noted in several studies 3,6,10 . In the Columbia-Presbiterian series infection was the precipitant of MC in as many as 38% of patients.…”

“…If not treated, the weakness progresses compromising respiratory muscles, leading to respiratory insufficiency and, ultimately, death 1,3,[6][7][8] . The death rate of MC has drastically decreased after the fifties, from 80% to less than 10%, thanks to the use of early mechanical ventilation, admission of the myasthenic patient to an Intensive Care Unit (ICU), recognition and treatment of precipitating factors, edrophonium testing, use of anticholinesterase drugs, steroid therapy, immunosuppression, plasmapheresis and IV human gamma globulin 1,3,6 .…”

Safety of influenza vaccination in patients with myasthenia gravis: A population‐based study

“…Episodes severe enough to require mechanical ventilation occur commonly in patients with MG, resulting in significant morbidity. [1][2][3][4] Several stressors are thought to trigger the disease, including infection, surgery, pregnancy, and some medications. Respiratory infections are believed to be the precipitating cause in 38% of MG exacerbations that require mechanical ventilation.…”