Integrating structured point-of-care ultrasound into dengue fever management: A mini review and comprehensive clinical guide

Table 2 Summary of potential issues during each phase of dengue fever and their relevant point-of-care ultrasound (POCUS) findings

Phase of disease	Potential issues	Expected finding(s)	POCUS characteristics
Febrile phase	Dehydration (normal-mildly raised serum lactate)	No signs of plasma leakage	Step 1: A-profile
			Step 2: Absence of free fluid
			Step 3: Normal GBWT
		Small IVC diameter	Step 4: Small IVC with > 50% collapsibility
		Underfilled ventricles	Step 5: Underfilled left ventricle
Critical phase	Plasma leakage (raised hematocrit and raised serum lactate)	Pulmonary interstitial edema	Step 1: B-profile
		Pleural effusion	Step 2: Presence of pleural effusion
		Free fluid in abdomen	Step 2: Presence of ascites
		Gallbladder wall thickening with pericholecystic fluid	Step 3: Gallbladder wall thickening (> 3 mm)
		Small IVC diameter	Step 4: Small IVC with > 50% collapsibility
		Pericardial effusion or myocardial dysfunction	Step 5: Presence of pericardial effusion or depressed left ventricular ejection fraction
	Bleeding (reducing hematocrit with raised serum lactate)	Normal or pulmonary interstitial edema	Step 1: A-profile or B-profile
		Free fluid in abdomen or normal finding	Step 2: Presence of ascites
		Gallbladder wall thickening with pericholecystic fluid or normal gallbladder	Step 3: Gallbladder wall thickening (> 3 mm)
		Normal or small IVC diameter	Step 4: Small IVC with > 50% collapsibility
	Dengue cardiomyopathy	Myocardial dysfunction	Step 5: Depressed left ventricular ejection fraction
Recovery phase	Reabsorption (systemic congestion with improving serum lactate)	Pulmonary interstitial edema	Step 1: B-profile
		Pleural effusion	Step 2: Presence of pleural effusion
		Free fluid in abdomen	Step 2: Presence of ascites
		Resolution of gallbladder wall thickening	Step 3: Resolution of gallbladder wall thickening
		Prominent IVC diameter	Step 4: Prominent IVC (> 2.1 cm) with < 50% collapsibility

Point-of-care ultrasound (POCUS) characteristics across different phases of dengue: Based on dengue POCUS protocol illustrated in Figure 2. GBWT: Gallbladder wall thickness; IVC: Inferior vena cava; POCUS: Point-of-care ultrasound.