Outcome of very old patients on mechanical ventilation

Background

The population group of 85 years old or more, classified as very old, are the most rapidly growing group in developed countries, although it still represents 0.46% of the Brazilian population. Aging is associated with decreased cardiopulmonary and renal reserve as well as the development of progressive organ failure.

Objective

To evaluate outcomes of very old patients in mechanical ventilation.

Patients and methods

A prospective cohort study in the medical/surgical ICU of a tertiary-care Brazilian hospital. Two hundred and forty-four patients aged 85 years old or more were selected from 7,410 patients admitted to the ICU from October 2002 to September 2006. Data were extracted from the QUATI (Dixtal-Brazil) database and included sex, age, APACHE II score, ventilation-days, length of stay, incidence of sepsis, tracheotomy, dialysis therapy and hemodynamic monitoring. For statistical analysis we used the chi-square test for evaluated difference of proportion, and considered statistical significance as P < 0.05.

Results

There were 168 female (68.9%) and 75 male (30.7%) patients. The mean age of the study population and the APACHE II score were 89.55 ± 3.61 years and 17.98 ± 6.3, respectively. Median ventilation-days and length of stay were 6 and 8.14 days, respectively. Tracheotomy was performed in 44.1%, dialysis therapy in 15.2% and hemodynamic monitoring in 19.8%. Only the group above 95 years old had a significant increase of days of ventilation and length of stay: 18.77 vs 10.47 days (P = 0.01) and 19.74 vs 12.86 days (P = 0.07), respectively. The predicted APACHE II mortality for the studied population was 26.9 ± 17.21% and the present rate to the population studied was 47.7%. Patients in dialysis and with diagnosis of sepsis at admission had poorer prognosis (respectively a 1.6 and 1.52 times likely ratio to die).

Conclusion

The percentage of older patients admitted to the ICU is increasing. The need for tracheotomy and dialysis as well as the length of stay are increasing with this population. APACHE scores do not seem to present a good relationship with mortality in this population. Dialysis and sepsis were associated with a significant increase in mortality.