"Oldest old" patients in intensive care: prognosis and therapeutic activity

Abstract

In view of ethical considerations and the limited resources in intensive care medicine, the present investigation aims to give a descriptive overview of the prognosis and therapeutic activity for the oldest age group of elderly patients admitted to an intensive care unit (ICU) in comparison with younger ICU patients. 3069 patients admitted to the ICU during a seven-year period were categorized into four age groups: under 65 years (48%), 65 to 74 years (26%), 75 to 85 years (22%) and 85 years or older (5%). Type and reason for ICU admission, length of ICU stay, severity of illness as measured by the simplified acute physiology score (SAPS)-II, level of provided care as measured by the simplified therapeutic intervention scoring system (TISS)-28, and vital status at the date of ICU discharge were recorded. The ICU mortality rate of patients aged 85 years or older was significantly higher than in patients under 65 (OR of mortality: 1.8, p < 0.001). Non-survivors had higher SAPS II levels (even when excluding age points) in all age groups, but higher daily average TISS points only in patients under 85. The daily average TISS score was negatively correlated to age (r = -0.03; p < 0.001) and was significantly lower in the oldest group when compared with all the younger groups (p < 0.001). The oldest patients had a significantly shorter length of stay (median: 2; interquartile range [IQR] 1-3, p < 0.001) than the younger patient groups. Within the very elderly population, age is an important and independent predictor of mortality, but acute severity of illness is even more strongly associated with mortality. Consequently, age alone may be an inappropriate criterion for allocation of ICU resources.