Predictors of Mortality in Scrub Typhus Infection Requiring Intensive Care Admission in Tertiary Healthcare Centre of Nepal

Abstract

Introduction. This study aimed to explore the predictors of mortality from scrub typhus infection in patients requiring intensive care unit (ICU) admission. Materials and Methods. A retrospective study was conducted on 120 patients with serum ELISA IgM positive for scrub typhus (optical density ≥ 0.5) admitted at the medical ICU of Chitwan Medical College Teaching Hospital between April 2016 and September 2017. Data was extracted from patient medical records and electronic database of the hospital. The outcome measurement was mortality (Yes/No) due to the infection. A multivariate binary logistic regression analysis (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.10</mml:mn></mml:math>) using potential variables from bivariate analysis (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.25</mml:mn></mml:math>) was adjusted to predict the mortality. Results. The mortality rate was 20% (24/120). Factors associated with mortality, as found using bivariate analysis, were heart rate &gt; 100/minute (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.001</mml:mn></mml:math>), systolic blood pressure &lt; 90 mmHg (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.025</mml:mn></mml:math>), diastolic blood pressure &lt; 60 mmHg (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M5"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.032</mml:mn></mml:math>), serum creatinine &gt; 1.4 mg/dl (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M6"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.001</mml:mn></mml:math>), acute kidney injury requiring dialysis (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M7"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.029</mml:mn></mml:math>), acute respiratory distress syndrome (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M8"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.001</mml:mn></mml:math>), and shock requiring vasopressor (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M9"><mml:mi>p</mml:mi><mml:mo>&lt;</mml:mo><mml:mn fontstyle="italic">0.001</mml:mn></mml:math>). Regression analysis showed age (odds ratio [OR] = 1.063; 95% CI = 1.010–1.118;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M10"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.019</mml:mn></mml:math>) and serum creatinine (OR = 1.063; 95% CI = 1.010–1.118;<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M11"><mml:mi>p</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.019</mml:mn></mml:math>) as significant predictors of poor outcome. Conclusion. Older age and high serum creatinine were found to be independent predictors of poor outcome in patients with scrub typhus admitted in medical ICU.