Ability of Bedside Ultrasound to Predict Progression of Severity of Disease in Dengue Fever

Dengue fever has various levels of severity, from mild disease to severe hemorrhagic complications and shock. Dengue is endemic world-wide and has been found in the United States. The mortality from dengue fever can be as high as 15-20%, with nearly 22,000 deaths annually, most of them children (Reddy, 2013). There is no reliable way to immediately predict which children presenting with a fever during a Dengue fever outbreak will progress to more severe disease. Some children with dengue fever will improve with limited clinical interventions, but others require intensive therapy. Limited healthcare resources in developing countries make decisions on treatment or disposition difficult as many children and poor clinical decision increase morbidity and mortality. In more developed countries such as the United States, early identification of patients with dengue fever has the potential to identify children who may benefit from early interventions. Identifying those patients is the first step in exploring early therapies to effect mortality. Previous research has demonstrated that intrathoracic/ peritoneal fluid and gallbladder wall thickening is associated with worsening of the clinical prognosis for hospitalized patients with dengue fever (Michels, 2013). We will explore earlier presentations in the emergency department and outpatient department.

Our hypothesis is that the presence of gallbladder wall thickening and/or pleural effusions in children correlates with progression to Dengue hemorrhagic fever and Dengue shock. In addition, we hypothesize that sonographic imaging of pediatric patients presenting to the emergency department with a fever during a Dengue fever outbreak will change management and disposition. Our specific aim is to 1) compare the accuracy of bedside ultrasound detection of intra-thoracic fluid, peritoneal free fluid, and gallbladder wall thickening and physical exam versus physical exam alone in diagnosing dengue fever and 2) determine the association between sonographic features of dengue (intra-thoracic fluid and gallbladder wall thickening) and clinical outcome in children with dengue fever.

This study is a prospective observational clinical study in the emergency department, inpatient ward, intensive care unit, and outpatient department of the Angkor Hospital for Children in Siem Reap, Cambodia. Study subjects will include children 16 years or less, who present during the annual Dengue Fever outbreak with suspected Dengue fever. Subjects include children with an acute febrile illness, and two of the following: headache, retro-orbital pain, myalgias, arthralgia, rash, hemorrhagic manifestations, or plasma leakage (i.e. shortness of breath, abdominal distention/pain). Clinicians will determine their clinical suspicion of dengue, intended therapeutic interventions and disposition following a history and physical exam but before ultrasound imaging. Study personnel will perform diagnostic bedside ultrasound imaging of the gallbladder and peritoneal and pleural spaces (FAST exam) and the clinician again determine their clinical suspicion of Dengue, intended therapeutic interventions and disposition. Patients will be followed to determine clinical outcome, therapeutic interventions and disposition. The primary endpoint is progression of disease. The secondary endpoint will be change in clinical care provided in the emergency department related to ultrasound imaging.