The association between comorbid illness, colonization status, and acute hospitalization in patients receiving prolonged mechanical ventilation.
BACKGROUND
Long-term acute care (LTAC) hospitals provide specialized care for survivors of critical illness who require prolonged mechanical ventilation. These chronically ill patients often have multiple comorbidities and are colonized with antibiotic-resistant organisms. We investigated the association of comorbidities and colonization status with outcomes in patients requiring prolonged mechanical ventilation in an LTAC facility. We hypothesized that comorbidity burden and colonization with multiple drug resistant organisms would be associated with worse clinical outcomes.


METHODS
We performed a retrospective, cohort study of 157 mechanically ventilated subjects in an urban LTAC facility admitted from January 2007 to September 2009. Comorbidity burden was documented from pre-admission data using the Charlson Comorbidity Index. Colonization data were obtained from surveillance cultures. Outcomes studied included transfer back to acute care facilities, stay, and ventilator weaning status.


RESULTS
Within 60 days, 58.6% of subjects were transferred back to an acute care facility. The most common reason for transfer was infection/sepsis (37%). The Charlson Comorbidity Index of subjects transferred to acute care, versus those who were not, was 4.9 ± 3.1 versus 3.6 ± 2.7 (P = .01), an odds ratio of 1.1 for each 1-point increase in Charlson Comorbidity Index (95% CI 1.03-1.71, P = .02). Colonization with acinetobacter was associated with higher incidence of transfer (71% vs 51%, P = .01). The odds ratio for transfer to acute care was 1.3 for each additional organism colonizing a subject (95% CI 1.11-1.53, P = .006).


CONCLUSIONS
Higher comorbidity burden and colonization status were associated with increased risk of transfer to acute care. Further investigation is needed to clarify this relationship between comorbidity burden and colonization with change in clinical status.
Division of Pulmonary and Critical Care Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
Avelino C
AC
Verceles
Elizabeth J
EJ
Lechner
David
D
Halpin
Steven M
SM
Scharf
D000150:Acinetobacter / Q000302:isolation & purification; D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002353:Carrier State / Q000453:epidemiology* / Q000382:microbiology; D015897:Comorbidity; D003920:Diabetes Mellitus / Q000453:epidemiology; D024901:Drug Resistance, Multiple, Bacterial; D005260:Female; D006801:Humans; D006973:Hypertension / Q000453:epidemiology; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D010360:Patient Transfer; D012121:Respiration, Artificial; D012189:Retrospective Studies; D018805:Sepsis / Q000453:epidemiology; D012720:Severity of Illness Index; D013183:Sputum / Q000382:microbiology; D020521:Stroke / Q000453:epidemiology; D013997:Time Factors; D015300:Ventilator Weaning; D055815:Young Adult