Influence of the admission pattern on the outcome of patients admitted to a respiratory intensive care unit: does a step-down admission differ from a step-up one?

BACKGROUND

The outcomes of patients admitted to a respiratory ICU (RICU) have been evaluated in the past, but no study has considered the influence of location prior to RICU admission.

METHODS

We analyzed prospectively collected data from 326 consecutive patients admitted to a 7-bed RICU. The primary end points were survival and severity of morbidity-related complications, evaluated according to the patient's location prior to RICU admission. Three admission pathways were considered: step-down for patients transferred from the ICUs of our hospital; step-up for patients coming from our respiratory wards or other medical wards; and directly for patients coming from the emergency department. The secondary end point was the potential influence of several risk factors for morbidity and mortality.

RESULTS

Of the 326 subjects, 92 (28%) died. Overall, subjects admitted in a step-up process had a significantly higher mortality (P < .001) than subjects in the other groups. The mortality rate was 64% for subjects admitted from respiratory ward, 43% for those from medical wards, and 18% for subjects from both ICU and emergency department (respiratory ward vs medical ward P = .04, respiratory ward vs emergency department P < .001, respiratory ward vs ICU P < .001, medical ward vs emergency department P < .001, and medical ward vs ICU P < .001). Subjects admitted from a respiratory ward had a lower albumin level, and Simplified Acute Physiology Score II was significantly higher in subjects following a step-up admission. About 30% of the subjects admitted from a respiratory ward received noninvasive ventilation as a "ceiling treatment." The highest odds ratios related to survival were subject location prior to RICU admission and female sex. Lack of use of noninvasive ventilation, younger age, female sex, higher albumin level, lower Simplified Acute Physiology Score II, higher Barthel score, and absence of chronic heart failure were also statistically associated with a lower risk of death.

CONCLUSIONS

The pathway of admission to a RICU is a determinant of outcome. Patients following a step-up pattern are more likely to die. Other major determinants of survival are age, nutritional status and female sex.