Association of the SOFA score and mortality in elderly patients with severe sepsis and septic shock

Introduction

The SOFA score is an excellent predictive marker of outcome in sepsis; however, there are very few studies that relate it to mortality in elderly patients with sepsis and septic shock.

Objective

To assess the association of the SOFA score and other factors related to mortality in elderly patients with severe sepsis and septic shock.

Methods

A 3-month prospective cohort study of 30 patients aged ≥ 65 showing severe sepsis or septic shock (Consensus Conference of 1991). Arterial hypotension (systolic arterial pressure < 90 mmHg) corresponded to the 'time-zero' of the study. The variables used were: SOFA score on days 1, 3, 5, 7, 14, and 28, ΔSOFA (variation of the SOFA score on days 1 and 3), APACHE II, Troponin I dosage, BNP and RCP, plasma glucose levels, organ failures [1], the presence of previous cardiovascular disease, assessment of dependence and cognitive deficit [2, 3], length of ICU stay, and need for mechanical ventilation. We used Student's t test and the Fischer Exact test for a statistical analysis. We considered the significance level of 5%.

Results

The mean age of patients, of whom 60% were females, was 82 ± 9 years (minimum = 65, maximum = 99). The predominant diagnosis was septic shock in 67% of the cases, while 33% of the patients developed severe sepsis. On days 1, 3, 5, 7, 14, and 28, the SOFA score presented mean values of 7, 6, 4, 3, 2, and 2, respectively (minimum = 2 and maximum = 15), thus evidencing a significant relationship between the SOFA score on day 1 (P = 0.0001) and day 3 (P = 0.001), including Δ SOFA score (P = 0.043), and mortality. The number of failures was also associated with mortality when two or more organic failures (P = 0.001) were present. Age, gender, APACHE II, length of ICU stay, dependence level, presence of cognitive deficit and/or previous cardiovascular diseases, plasma glucose levels, troponin I, BNP and RCP were not associated with the mortality.

Conclusion

Mean SOFA average above 5 as well as SOFA variation within the first 72 hours proved to be good predictive markers in elderly patients with septic shock and severe sepsis. The same occurred in the presence of two or more organic failures during the course of sepsis.