Objective: The number of elderly patients admitted to intensive care unit (ICU) has been increased worldwide. Elderly patients are subjected to various physiologic changes related to aging process and it has been recognized that aging is an important predictor for mortality. The aim of this present study is to determine the hospital mortality and its associated risk factors in elderly patients admitted to general surgical ICU at a tertiary referral hospital in Thailand.
Material and Method: This was an analytic study that used database from the prospective observational cohort study conducted in two general surgical ICUs at Siriraj Hospital between April 2011 and November 2012. Elderly patients were defined as patients whose age of more than 70 years old. Demographic data and clinical outcomes were collected. The adjusted logistic regression analysis was performed to identify independent risk factors for hospital mortality.
Results: There were 377 elderly patients admitted to two general surgical ICUs, which was accounted for 41.7% of all admission and their mortality was 12.5% (95% CI 9.4 to 16.3). Three independent risk factors for hospital mortality in elderly patients admitted to ICU included APACHE II score of more than 15 (adjusted OR 6.79, 95% CI 3.29 to 14.79) and presence of coagulation and cardiovascular dysfunction at ICU admission (adjusted OR 3.72, 95% CI 1.52 to 9.09 and adjusted OR 2.65, 95% CI, 1.22 to 5.76; respectively).
Conclusion: Hospital mortality in elderly patients admitted to general surgical ICU was 12.5%. Among elderly patients, severity of acute illness was an important risk factor for hospital mortality.

Keywords: Elderly, Surgical, Critically ill, Intensive care unit, Mortality