Risk factors for intensive care unit admission in patients with severe leptospirosis: a comparative study according to patients' severity.

Background: The aim of this study is to investigate predictive factors for intensive care unit (ICU) admission among patients with severe leptospirosis.

Methods: This is a retrospective study with all patients with severe leptospirosis admitted to a tertiary hospital. Patients were divided in ICU and ward groups. Demographical, clinical and laboratory data of the groups were compared as well as acute kidney injury (AKI) severity, according to the RIFLE criteria (R = Risk, I = Injury, F = Failure, L = Loss, E = End-stage kidney disease).

Results: A total of 206 patients were included, 83 admitted to ICU and 123 to ward. Mean age was 36 ± 15.8 years, with 85.9% males. Patients in ICU group were older (38.8 ± 15.7 vs. 34.16 ± 15.9 years, p = 0.037), had a shorter hospital stay (4.13 ± 3.1 vs. 9.5 ± 5.2 days, p = 0.0001), lower levels of hematocrit (29.6 ± 6.4 vs. 33.1 ± 8.6%, p = 0.003), hemoglobin (10.2 ± 2.4 vs. 11.6 ± 1.9 g/dL, p < 0.0001), and platelets (94,427 ± 86,743 vs. 128,896 ± 137,017/mm(3), p = 0.035), as well as higher levels of bilirubin (15.0 ± 12.2 vs. 8.6 ± 9.5 mg/dL, p = 0.001). ICU group also had a higher frequency of severe AKI (RIFLE-"Failure": 73.2% vs. 54.2%, p < 0.0001) and a higher prevalence of dialysis requirement (57.3% vs. 27.6%, p < 0.0001). Mortality was higher among ICU patients (23.5% vs. 5.7%, p < 0.0001). Independent predictors for ICU admission were tachypnea (p = 0.027, OR = 13, CI = 1.3-132), hypotension (p = 0.009, OR = 5.27, CI = 1.5-18) and AKI (p = 0.029, OR = 14, CI = 1.3-150). Ceftriaxone use was a protective factor (p = 0.001, OR = 0.13, CI = 0.04-0.4).

Conclusions: Independent risk factors for ICU admission in leptospirosis include tachypnea, hypotension and AKI. Ceftriaxone was a protective factor for ICU admission, suggesting that its use may prevent severe forms of the disease.