Background: Asthma is one of the most common chronic medical conditions affecting around 300 million people worldwide. It is a disorder of the airways characterized by recurrent symptoms of airway obstruction and inflammation. Invasive mechanical ventilation for patients admitted to the hospital with asthma is challenging with higher complications and higher rates of patient-ventilator asynchrony, However, it should be used in the setting of acute respiratory failure refractory to treatment [1]. In this study, we examined the National Inpatient Sample (NIS) to determine the epidemiologic and medical complications and comorbidities associated with increased mortality in patients with asthma.

Methods: Adults with a principal diagnosis of asthma were selected from the 2019 US National Inpatient Sample, using ICD 10 code primary diagnosis on discharge. We queried the 2019 National Inpatient Sample for intubation, Noninvasive Positive-Pressure Ventilation (NPPV), pneumothorax, and shock using ICD 10 codes. Confounders were adjusted for using multivariable linear regression analysis.

Results: In a total of 102,365 adult patients with non-elective asthma, admissions were included from the 2019 national inpatient sample, during their stay in the hospital, 0.4 percent of these admissions died. On weighted analysis, Patients who were intubated for acute hypoxemic respiratory failure during admission had statistically significant higher odds for mortality compared to non intubated asthma patients [adjusted odds ratio (OR): 20.6; 95% confidence interval (CI): 9.1-46.7, P< 0.001]. Patients who had shock during a hospital stay have significantly higher odds for mortality compared to patients without shock [adjusted odds ratio (OR): 76.7; 95% confidence interval (CI): 23.6-249.1, P< 0.001], and patients with inpatient hospital pneumothorax have higher odds for mortality during the same hospital admission [adjusted odds ratio (OR): 10.9; 95% confidence interval (CI): 1.34-89.77, P=0.02]. However, treatment with NPPV did not show significant result for mortality when compared to patients not treated with NPPV [adjusted odds ratio (OR): 0.28; 95% confidence interval (CI): 0.5-1.5, P=0.14].

Conclusions: The overall in-hospital mortality rate for asthma patients was low (0.4 percent ). Our findings shed light on factors linked to a higher risk of tragic consequences. These variables were severe hypoxemic respiratory failure requiring intubation, in-hospital complications with shock, and pneumothorax. The identification of these variables in patients admitted with asthma symptoms and treated aggressively early on could result in a further reduction in mortality. In the study, NPPV use was not found to be an independent predictor of mortality.