Comparison of intensive-care-unit-acquired infections and their outcomes among patients over and under 80 years of age

Abstract

Patients aged >80 years represent a growing population admitted to intensive care units (ICUs). However, little is known about ICU-acquired infection (IAI) in this population, and the rate of invasive procedures is increasing. To evaluate the frequency and effects of IAI in elderly (≥80 years) and younger patients. Retrospective evaluation of consecutive patients hospitalized for three days or more over a three-year period in an 18-bed ICU in an academic medical centre. Elderly patients represented 18.9% of the study population. At admission, the mean number of organ dysfunctions was similar in elderly and younger patients. The use of invasive procedures was also similar in elderly and younger patients, as follows: invasive mechanical ventilation for more than two days, 67.4% vs 55%; central venous catheterization, 56.9% vs 51.4%; and renal replacement therapy, 17.6% vs 17.8%, respectively. The frequency of IAI was 16.5% in elderly patients and 13.9% in younger patients (P = 0.28), with 20.5 vs 18.9 IAI episodes per 1000 ICU-days, respectively (P = 0.2). A Cox model identified central venous catheterization and invasive mechanical ventilation for more than two days as independent risk factors for IAI. The associations between IAI and prolonged ICU stay, increased nursing workload, and ICU and hospital mortality rates were similar in elderly and younger patients. The frequency of IAI was similar in elderly and younger patients, as were the associations between IAI and length of ICU stay, nursing workload and ICU mortality in an ICU with a high rate of invasive procedures.