Abstract

Background: This study is conducted to see if calculating admission shock index (SI) or modified shock index (MSI) are useful to predict the 28 days mortality in geriatric patients admitted to intensive care unit (ICU) for medical reasons.

Methods: 446 patients over 60 years old with at least two comorbidities besides the reason for admission were included in this retrospective study. The first ICU admission data of systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), Glascow Coma Score, Acute Physiological and Clinical Health Evaluation-II Score, demographics and first laboratory and blood gas analysis results besides calculated SI (Heart rate/SBP) and MSI (Heart rate/MAP) were recorded. The patients were divided in two groups, according to the 28-days survival. The predictive value of SI and MSI and their cut off values for the 28th day mortality were detected. The impact of variables like serum creatinine and lactate levels were also assessed. Univariate and multivariate logistic regression analysis were performed to assess the impact of variables on outcome.

Results: Univariate regression analysis showed that increased risk of 28-day mortality associated with SI > 1.09 (Odds ratio (OR) = 4.15, 95% confidence interval (CI): 2.636.55) fold), MSI > 1,4 (OR = 3.76, 95% CI: 2.465.75), serum creatinine (OR = 1.27 for each 1 mg/dL increase, 95% CI: 1.121.44), and serum lactate (OR = 1.13 for each 1 mmol/L increase, 95% CI: 1.051.21.

Conclusion: SI and MSI indices can be used as a practical predictive measurement of mortality in critically ill elderly medical patients.