Predicting acute liver failure in dengue Infection

Abstract

BACKGROUND: Dengue infections (DI) can range from being asymptomatic to severe illness. Unusual manifestations such as encephalitis, myocarditis, and acute liver failure (ALF) have been recognized. ALF is uncommon, but has a poor prognosis. The aim of this study was to identify predictors of ALF in DI. METHODS: Serologically confirmed patients with DI who were admitted to hospital from January 2009 to March 2010 were included. Patients consisted of direct admissions as well as referrals, some with deranged liver functions. Data was obtained from patient records. Clinical details and serum biochemistry was evaluated for up to five days from onset of illness. ALF in DI was defined as evidence of coagulation abnormality [International normalised ratio (INR) ≥ 1.5], and any degree of mental alteration (encephalopathy) in a patient without pre-existing cirrhosis. RESULTS: Out of 240 patients [57.7% male, 42.3% female; mean age 35.6 years (SD 15.4 years)], 164 had dengue with warning signs, 27 had dengue without warning signs and 49 had severe dengue. 15/49 severe dengue patients had profound shock. Abdominal pain, persistent nausea and vomiting (PNV), bleeding, hepatomegaly and ascites were present in 125, 92, 39, 129 and 28 cases respectively. Elevated aspartate aminotransferase (AST), serum bilirubin (SB), alkaline phosphatase (ALP) and gamma glutamyl transpeptide (GGT) were observed in 208, 20, 18 and 60 patients respectively. Of the 240 patients 41 had AST .1000 IU/ml (this included 4/ 15 with profound shock). 16/41 patients with AST .1000 IU/ml, including 4 with profound shock, developed ALF while none with AST ,1000 IU/ml developed ALF. In patients with AST .1000 IU/ml, presence of 2 or 3 of elevated SB, elevated ALP or PNV predicted the development of ALF with 93.8% sensitivity, 98.7% specificity, 83.3% positive predictive value and 99% negative predictive value (Fisher's exact test). CONCLUSIONS: Dengue patients with AST,1000 IU/ml are not at risk of developing ALF. Patients with AST .1000 (regardless of presence or absence of profound shock), with 2 or 3 of elevated SB, elevated ALP or PNV seem to be at risk of developing ALF. These findings need to be validated in a larger cohort of patients.