Prognostic factors of elderly patients admitted to an ICU

Introduction

The world's population is becoming older, which affects the ICU population. Elderly patients constitute 42–52% of all admissions to the ICU. It is therefore necessary to establish the risks of this group of patients, aiming to offer proper treatment. The aim of this study was to identify risk factors of an elderly population of patients admitted to the ICU.

Methods

A prospective longitudinal cohort study in a general ICU of a tertiary hospital, between 1 December 2006 and 30 April 2007. Inclusion criteria were patients above or equal to 65 years old, admitted to the ICU for at least for 24 hours. Exclusion criteria were moribund patients, patients with terminal diseases and patients readmitted to the ICU.

Results

One hundred and ninety-nine patients were enrolled, with mean age of 75.4 years, 58.8% female. The ICU and inhospital mortalities of this population were 28.1% and 57.3% respectively. Mean values of APACHE II, SOFA, MODS and Katz index (Activities of Daily Living Scale) were, respectively, 20.0 ± 5.8, 6.8 ± 3.9, 2.4 ± 1.9 and 5.3 ± 1.6. A total 61.1% of the patients were in postoperative status; of them, 41.6% were under mechanical ventilation and 39.1% required vasoactive drugs. Independent risk factors of a high mortality rate (death versus ICU discharge) were: advanced age (76.9 ± 6.7 years vs 73.3 ± 6.5 years; OR = 1.08; 95% CI = 1.01–1.16; P < 0.001), Katz index (4.9 ± 1.9 vs 5.7 ± 0.9; OR = 0.66; 95% CI = 0.45–0.98; P = 0.001), hyperglycemia (158.1 ± 69.0 vs 139.6 ± 48.5; OR = 1.02; 95% CI = 1.01–1.03; P = 0.041) and requirement for mechanical ventilation at ICU admission (57.0% vs 20.5%; OR = 3.57; 95% CI = 1.24–10.3); P < 0.001).

Conclusion

Prognosis was more dependent on severity of illness and functional status before admission than on high age itself. Traditional prognostic models such as APACHE II, SOFA and MODS were not discriminative. We need a new prognostic score validated in elderly ICU patients that predicts not only survival but also functional and cognitive status after discharge.