Ultrasound findings of plasma leakage as imaging adjunct in clinical management of dengue fever without warning signs

INTRODUCTION: Plasma leakage is a major cause of morbidity and mortality in dengue fever. Few studies have shown the sensitivity of thoracoabdominal ultrasound in detecting plasma leakage in severe dengue, however its sensitivity in the early presentation of dengue fever without warning signs remains unknown. This study is aimed to determine the role of serial ultrasound in order to detect plasma leakage in dengue fever without warning signs.

METHODS: This prospective cohort study was conducted at Hospital Universiti Sains Malaysia (USM) from 1st October 2016 to 30th November 2017. Serial bedside ultrasound procedures were performed for 83 patients who were diagnosed as having dengue fever without warning signs and were initially treated as outpatients. Ultrasonography evidence of plasma leakage either pleural effusion, thickened gallbladder wall, ascites or pericardial effusion were compared with clinical findings and laboratory parameters for plasma leakage.

RESULTS: Of the 83 dengue patients, eventually 72.3% had dengue fever with warning signs and 6.0% had severe dengue fever. There were 38 patients who had subclinical plasma leakage at initial presentation, 84.2% and 7.9% of them then progressed to dengue fever with warning signs and severe dengue respectively. There was a minimal agreement between serial bedside ultrasound and haematocrit level in the detection of plasma leakage (observed kappa 0.135).

CONCLUSIONS: Serial bedside ultrasound is an adjunct procedure to physical examination and may detect plasma leakage earlier compared to haemoconcentration. The early usage of serial ultrasound is of paramount importance in detecting dengue patients who are at risk of progressing to severe dengue.