Correlates of prolonged hospitalization in inner-city ICU patients receiving noninvasive and invasive positive pressure ventilation for status asthmaticus

Study objectives: To describe the outcome of patients with status asthmaticus (SA) treated in a medical ICU with positive pressure ventilation (PPV), and to identify those factors associated with increased length of hospital stay. Design: Retrospective chart review. Setting: University-based hospital in Chicago, IL. Patients: All patients admitted with SA and treated with PPV over a 5-year period. Results: The first ICU admission for each of 78 patients was analyzed. Fifty-six patients underwent endotracheal intubation (ETI) during the hospitalization, while 22 patients were treated with noninvasive PPV alone. Three patients died. The median hospital length of stay was 5.5 days. Cox regression analysis revealed the following factors to be independently associated with increased length of hospital stay: female gender (p < 0.01), ETI (p < 0.01), the administration of neuromuscular blockers for > 24 h (p < 0.01), inhaled corticosteroid use prior to ICU admission (p = 0.01), and increasing APACHE (acute physiology and chronic health evaluation) II score (p < 0.01). Conclusions: This study suggests that while the mortality associated with SA treated with contemporary methods of PPV is low, certain factors, including female gender, ETI, and the prolonged use of neuromuscular blockade, are associated with an increased length of hospital stay. The development of respiratory failure despite preadmission use of inhaled corticosteroids is also associated with prolonged hospitalization.