Clinical course and outcome of patients admitted to an ICU for status asthmaticus.

STUDY

OBJECTIVES

To describe the prognostic factors, clinical course, and outcome of patients with status asthmaticus treated in a medical ICU (MICU).

DESIGN

Analysis of prospective data.

SETTING

A multidisciplinary MICU of an inner-city university hospital.

PATIENTS: We collected data on 132 hospital admissions of 89 patients with status asthmaticus treated in our MICU from August 1995 through July 1998.

MEASUREMENTS: APACHE (acute physiology and chronic health evaluation) II scores were among the parameters measured.

RESULTS

Seventy-nine percent of the patients were female, and 67% were African American (mean +/- SD age, 42.4 +/- 15.1 years). Patients in 48 of the 132 hospital admissions (36%) required invasive mechanical ventilation; sepsis developed in patients during 17 hospital admissions (13%), nonpulmonary organ failure developed during 16 hospital admissions (12%), and ARDS developed during 2 hospital admissions (2%). Pneumothorax developed in four patients and required tube thoracostomy in all four patients. The median APACHE II score was 11. Predicted mortality and actual mortality were 6.7% and 8.3%, respectively. The two most common immediate causes of death were pneumothorax (n = 3) and nosocomial infection (n = 3). All the deaths occurred in female patients. Compared with survivors, nonsurvivors had higher APACHE II scores (median, 26 vs 15; p < 0.0001), PaCO(2) (63.8 +/- 21.3 mm Hg vs 47.8 +/- 19.1 mm Hg, p = 0.0101), and lower arterial pH (7.09 +/- 0.12 vs 7.27 +/- 0.12, p < 0.0001), respectively. Patients in 10 of 48 hospital admissions (21%) who required mechanical ventilation died.

CONCLUSIONS

The hospital mortality of patients admitted to an MICU for status asthmaticus is higher than expected. Higher APACHE II score and PaCO(2) and lower arterial pH within 24 h of hospital admission are associated with increased mortality. Sepsis and nonpulmonary organ failure are more likely to develop in nonsurvivors than survivors.