Epidemiology and clinical characterization of patients with acute respiratory failure admitted to a general ICU

Objective

To study the prevalence and mortality of ARF and characteristics of the patients with ARF admitted to a general ICU.

Methods

During 6 months, all adult patients admitted to a 17-bed ICU in Salvador, Bahia, Brazil who had ARF defined as a patient receiving mechanical ventilation for more than 24 hours were prospectively studied.

Results

From March to August 2008, there were 411 admissions to the ICU. From these, 82 (20%) patients received mechanical ventilation for more than 24 hours with a median duration of 4 days (varied from 1 to 69 days). The characteristics of patients with ARF are presented in Table 1. These patients were older than the total population admitted to the ICU (68 vs 65 years, P < 0.05), had higher APACHE II score (19 vs 13, P < 0.0001), higher ICU stay (10.5 vs 3.0 days, P < 0.001) and higher mortality (51.2 vs 17.5%, P < 0.0001). Mortality of ARF patients was associated with old age, odds ratio of 3.0 for death for patients older than 70 years (95% CI = 1.2 to 7.5), and development of complications in the ICU (OR = 8.4, 95% CI = 3.1 to 22.8).

Table 1 Characteristics of 82 patients with acute respiratory failure

Conclusion

ARF prevalence was 20% in the studied population. The main cause of ARF was sepsis, these patients were older, more severely ill, had higher ICU stay and mortality than the total population admitted to the ICU and were often complicated with multiple organ failure.