Use Of Critical Illness Scoring Systems (SOFA, APACHE II and qSOFA) to Predict the Clinical Outcomes in Scrub Typhus Patients With Organ Dysfunctions

Abstract

Background. Scrub typhus, an arthropod vector borne rickettsial disease caused by Orientia tsutsugamushi, is frequently associated with organ dysfunctions. We studied the performance of critical illness scoring systems (APACHE-II, SOFA and quick-SOFA [qSOFA]) in predicting the clinical outcomes in scrub typhus patients with organ dysfunctions. Methods. Prospective study of patients who were admitted with acute febrile illness and were diagnosed to have Scrub typhus with one or more organ dysfunctions was done during a 12-month period at a tertiary referral center in North India. APACHE II, SOFA and qSOFA scores at admission were calculated and were analyzed in predicting the clinical outcomes, which includes discharge or death and the duration of in-hospital stay. Results. In our cohort of 50 patients having 29 males and 21 females patients (male/female ratio 1.5:1) with age 34 +/- 15 years, fever was the most common symptom (100%) with duration of 8.2 +/- 4 days followed by dyspnea (64%), altered sensorium (30%), jaundice (28%), abdominal pain (26%), vomiting (20%) and oliguria (16%). Three patients (6%) had an eschar and 2 patients (4%) had rashes. Among organ dysfunctions, thrombocytopenia (82%) was the most common followed by acute respiratory distress syndrome (66%), acute kidney injury (42%), acute meningoencephalitis (18%) and acute liver failure (6%). Death was observed in 4 patients (8%). The mean APACHE II, SOFA and qSOFA of the cohort were 17.9 +/- 7, 8.2 +/- 3.6, and 1.6 +/- 0.78, respectively. On bi-variate analysis, both qSOFA (P = 0.001) and SOFA (P = 0.031) scores were able to predict the mortality independently. The duration of in-hospital stay was 9.1 +/- 6.8 days. A linear relation was observed between the SOFA score with the duration of in-hospital stay (Pearson correlation = 0.311, P = 0.028) when compared to APACHE II and qSOFA scores. Conclusion. In scrub typhus patients with organ dysfunctions, SOFA score correlates with the mortality and duration of in-hospital stay when compared with APACHE II. The qSOFA score, which includes the presence or absence of tachypnea (>22/min), systolic hypotension (<100 mm Hg) and altered mentation, is a simple and convenient tool to predict the mortality in scrub typhus with organ dysfunctions.