Hemogram parameters can predict in-hospital mortality of patients with Myasthenic crisis

Abstract

Background Myasthenia gravis (MG) is an autoimmune disease involving the neuromuscular junction. Myasthenic crisis (MC), which is characterized by respiratory failure and the requirement of mechanical ventilation in patients with MG, is still a medical emergency despite the decrease in mortality with the advances in acute management. Hemogram is a cost-effective test for evaluating hematological complications and systemic inflammation, and hemogram data have been used to predict various clinical outcomes of several diseases. The relationship between hemogram and MG has been discussed, but the role of hemogram data in predicting the prognosis of MC patients has not been established. Methods To identify whether hemogram data can predict in-hospital mortality in patients with MC, we retrospectively investigated 188 myasthenic crisis events from the Chang Gung Research Database between April 2001 and March 2019. Demographic and clinical characteristics were collected, as well as hemogram data before intubation and extubation. The endpoints were mortality during mechanical ventilation and mortality after extubation. Results The overall in-hospital mortality rate was 22%. Multivariate logistic regression analysis for predicting mortality during mechanical ventilation showed that old age at MC onset (OR = 1.039, p = 0.022), moderate-to-severe anemia (OR = 5.851, p = 0.001), and extreme leukocytosis (OR = 5.659, p = 0.022) before intubation were strong predictors of mortality, while acute management with plasma exchange or double-filtration plasmapheresis (PE/DFPP) significantly decreased mortality (OR = 0.236, p = 0.012). For predicting mortality after extubation, moderate-to-severe anemia before extubation (OR = 8.452, p = 0.017) and non-treated with disease-modifying therapy before MC (OR = 5.459, p = 0.031) were crucial predictive factors. Conclusion This study demonstrated that both old age at MC onset and moderate-to-severe anemia are important predictors of in-hospital mortality in patients with MC, and extreme leukocytosis is another crucial predictor of mortality during mechanical ventilation. The suggested mechanism is that anemia-induced hypoxia may enhance the release of proinflammatory cytokines, exacerbate systemic inflammation, and lead to multiple organ dysfunction syndrome and, finally, mortality.

Identifying patients at risk for myasthenic crisis with hemogram and inflammation-related laboratory parameters – a pilot study

“…Our study provides initial indications that routine laboratory parameters assessed before the onset of MC could be used as risk predictors for MC occurrence and facilitate early interventions (e.g., treatment with immunoglobulins or plasma exchange), possibly preventing MC and mitigate the associated morbidity and mortality. To this end, some studies have investigated prediction of in-hospital mortality in MC based on selected laboratory parameters (22, 35). A recent study derived a predictive score for in-hospital mortality of MC which used Myasthenia Gravis Foundation of America (MGFA) score at onset of the MC, septic shock, and cardiac arrest (35).…”

“…The latter may corroborate our findings that increased leukocyte counts may be associated with increased risk for an ensuing MC. Further studies described a possible association between infections (36) and signs of inflammation (leukocytosis) (22) with an increased risk of developing MC. Furthermore, hemogram could provide clues to the course of the disease, as hematological changes have been identified as prognostic factors of mortality for several critical illnesses (22), e.g., endocarditis (37), acute kidney injury (38), and acute myocardial infarction (39, 40).…”

“…Although it is known that certain drugs, inadequate treatment, surgery, infection, sepsis, and pregnancy can trigger MC (9, 18, 19), the prediction of severe exacerbation of MG or ultimately MC based on laboratory parameters is currently not possible. To this end, so far only a few studies investigated the relationship between hemogram or inflammation-related laboratory parameters and disease progression of MG (20–22).…”

Myasthenic crisis

“…Predictors of mortality include age > 50 y, severe MG status, severe anemia, septic shock, cardiac arrest, number of comorbidities, ARDS and resuscitation need. 6,[12][13][14]91,92 In a retrospective study of 5000 hospital admissions for MG, there were no deaths observed in those <40 y of age, highlighting the importance of age and medical comorbidities as modifying factors for the mortality of MC. 14 Owing to better respiratory care and increased disease modifying treatment options, the prognosis of MC has improved strikingly over the last century.…”

“…Data on mortality worldwide range between 2 to 16%. Predictors of mortality include age > 50 y, severe MG status, severe anemia, septic shock, cardiac arrest, number of comorbidities, ARDS and resuscitation need 6,12–14,91,92 . In a retrospective study of 5000 hospital admissions for MG, there were no deaths observed in those <40 y of age, highlighting the importance of age and medical comorbidities as modifying factors for the mortality of MC 14 …”