Ultrasound in Dengue: A Scoping Review

Severe dengue in the intensive care unit

Dengue fever is considered the most prolific vector-borne disease in the world, with its transmission rate increasing more than eight times in the last two decades. While most cases present mild to moderate symptoms, 5% of patients can develop severe disease. Although the mechanisms are yet not fully comprehended, immune-mediated activation leading to excessive cytokine expression is suggested as a cause of the two main findings in critical patients: increased vascular permeability that may shock and thrombocytopenia, and coagulopathy that can induce hemorrhage. The risk factors of severe disease include previous infection by a different serotype, specific genotypes associated with more efficient replication, certain genetic polymorphisms, and comorbidities such as diabetes, obesity, and cardiovascular disease. The World Health Organization recommends careful monitoring and prompt hospitalization of patients with warning signs or propensity for severe disease to reduce mortality. This review aims to update the diagnosis and management of patients with severe dengue in the intensive care unit.

Evaluation of remote radiologist-interpreted point-of-care ultrasound for suspected dengue patients in a primary health care facility in Colombia

BACKGROUND

Early identification of plasma leakage may guide treatment decisions in dengue patients. This study evaluated the value of point-of-care ultrasound (POCUS) to detect plasma leakage and predict hospitalization or referral to a higher level of care in suspected dengue patients under routine conditions at a primary care facility in Colombia.

METHODS

We conducted a cohort study between April 2019 and March 2020 in a primary care hospital in Cali, Colombia. We prospectively included and followed 178 patients who were at least 2 years old with fever of less than 10 days and clinician-suspected dengue. A trained general practitioner performed a standardized POCUS protocol. Images were quality-rated and overread by an expert radiologist, and her results and those of the general practitioner were compared using the Kappa index. Logistic regression was used to identify factors associated with plasma leakage at enrollment and explore its prognostic value regarding hospital admission or referral to a higher level of care.

RESULTS

Half (49.6%) POCUS images were of suitable quality to be interpreted. The proportion of plasma leakage reported by the radiologist was 85.1% (95% CI: 78.6-90.2%) and 47.2% by the study physician (Kappa = 0.25, 95% CI: 0.15-0.35). The most frequent ultrasound findings were ascites (hepatorenal 87.2%, splenorenal 64%, or pelvic 21.8%) and gallbladder wall thickening (10.5%). Plasma leakage was higher in subjects with thrombocytopenia (aOR = 4, 95% CI: 1.3-12.1) and lower in patients 30-59 years old (aOR = 0.1, 95% CI: 0.0-0.4) than in those 18 years old or younger. POCUS evidence of plasma leakage (aOR = 8.2, 95% CI: 2.2-29.9), thrombocytopenia (aOR = 6.3, 95% CI: 2.4-16.0) and pulse pressure (aOR = 1.1, 95% CI: 1.07-1.2) were associated with hospital admission or referral to a higher level of care.

CONCLUSIONS

Ultrasound is useful to detect plasma leakage in primary care and, challenges remain to guarantee high-quality images and diagnostic accuracy, for which a standardized dengue POCUS protocol and training program is needed.

Neurological Manifestations of Perinatal Dengue

Dengue viruses (DENVs) are single-stranded RNA viruses belonging to the family Flaviviridae. There are four distinct antigenically related serotypes, DENVs types 1, 2, 3, and 4. These are all mosquito-borne human pathogens. Congenital dengue disease occurs when there is mother-to-fetus transmission of the virus and should be suspected in endemic regions in neonates presenting with fever, maculopapular rash, and thrombocytopenia. Although most of the infected infants remain asymptomatic, some can develop clinical manifestations such as sepsis-like illness, gastric bleeding, circulatory failure, and death. Neurological manifestations include intracerebral hemorrhages, neurological malformations, and acute focal/disseminated encephalitis/encephalomyelitis. Dengue NS1Ag, a highly conserved glycoprotein, can help the detection of cases in the viremic stage. We do not have proven specific therapies yet; management is largely supportive and is focused on close monitoring and maintaining adequate intravascular volume.

A survey of barriers and facilitators to ultrasound use in low- and middle-income countries

Point-of-care ultrasound has the potential to help inform assessment, diagnosis, and management of illness in low- and middle-income countries (LMIC). To better understand current ultrasound use, barriers and facilitators to use, and perceptions and practices in LMIC, we conducted an anonymous online global survey targeting healthcare providers training and using ultrasound in LMIC. A total of 241 respondents representing 62 countries participated and most were physicians working in publicly-funded urban tertiary hospitals in LMIC. Most had received ultrasound training (78%), reported expertise (65%) and confidence (90%) in ultrasound use, and had access to ultrasound (88%), utilizing ultrasound most commonly for procedures and for evaluations of lungs, heart, and trauma. Access to an ultrasound machine was reported as both the top barrier (17%) and top facilitator (53%); other common barriers included access to education and training, cost, and competition for use and other common facilitators included access to a probe, gel, and electricity, and acceptance by healthcare providers, administrators, and patients. Most (80%) noted ultrasound access was important and 96% agreed that ultrasound improves quality of care and patient outcomes. Improving access to low-cost ultrasound equipment is critical to increasing ultrasound use among those who are trained.

Clinical features and management of children with dengue-associated obstructive shock syndrome: A case report

RATIONALE

Dengue obstructive shock syndrome is a fatal complication commonly observed in the late critical phase of dengue infection and is associated with a high mortality rate. The main pathogenesis involves a dramatic increase in chest pressure, owing to severe plasma leakage and mechanical respiratory support, hampering the heart's ability to pump effectively and impeding adequate blood venous return to the heart chambers. To date, there is a paucity of clinical data about Dengue obstructive shock syndrome reported.

PATIENT CONCERNS

The 2 reported patients presented with prolonged and decompensated dengue shock with critical multi-organ failures and mechanical ventilation. The patients' hemodynamics were profoundly affected by high pressure in the thoracic and abdominal cavities resulting from Dengue-induced severe plasma leakage and mechanical ventilation.

DIAGNOSES

Clinical presentations, laboratory data, mini-fluid challenge test, and point-of-care (POCUS) were used to make diagnoses and guide management.

INTERVENTIONS

Clinical monitoring, judicious fluid (colloids and blood products) administration guided by repeated POCUS to properly assess the adequacy of the intravascular volume, homeostasis adjustments by plasma exchange, and continuous renal replacement therapies.

OUTCOMES

The patients had favorable outcomes.

LESSONS

Our study highlights the clinical manifestations and management of children with dengue obstructive shock syndrome and underscores the importance of monitoring hemodynamics by consecutive POCUS at the bedside in order to make a timely diagnosis and assess intravascular fluid volume inadequacy accurately as well as closely monitor the fluid management responses.

Task shifting for point of care ultrasound in primary healthcare in low- and middle-income countries-a systematic review

Low-and middle-income countries (LMIC) are faced with healthcare challenges including lack of specialized healthcare workforce and limited diagnostic infrastructure. Task shifting for point-of-care ultrasound (POCUS) can overcome both shortcomings. This review aimed at identifying benefits and challenges of task shifting for POCUS in primary healthcare settings in LMIC. Medline and Embase were searched up to November 22nd, 2021. Publications reporting original data on POCUS performed by local ultrasound naïve healthcare providers in any medical field at primary healthcare were included. Data were analyzed descriptively. PROSPERO registration number CRD42021223302. Overall, 36 publications were included, most (n = 35) were prospective observational studies. Medical fields of POCUS application included obstetrics, gynecology, emergency medicine, infectious diseases, and cardiac, abdominal, and pulmonary conditions. POCUS was performed by midwives, nurses, clinical officers, physicians, technicians, and community health workers following varying periods of short-term training and using different ultrasound devices. Benefits of POCUS were yields of diagnostic images with adequate interpretation impacting patient management and outcome. High cost of face-to-face training, poor internet connectivity hindering telemedicine components, and unstable electrici'ty were among reported drawbacks for successful implementation of task shifting POCUS. At the primary care level in resource-limited settings task shifting for POCUS has the potential to expand diagnostic imaging capacity and impact patient management leading to meaningful health outcomes.

Dengue Management in Triage using Ultrasound in children from Cambodia: a prospective cohort study

BACKGROUND

Dengue is a mosquito-borne viral infection with increasing global prevalence. It is endemic in more than 100 countries, with a heavy burden in Asia. Ultrasound findings including gallbladder wall thickening, ascites, and pleural effusions secondary to plasma leakage have been described in dengue. We aimed to determine if the presence of point-of-care ultrasound findings early in suspected dengue could predict clinical worsening in ambulatory pediatric patients.

METHODS

We did a prospective, single-blinded, observational cohort study at a children's hospital in Siem Reap, Cambodia during periods of dengue outbreak. Ambulatory patients were screened and children ages > 3 month and ≤ 16 years with suspected acute, non-severe dengue were enrolled. Subjects had chest and abdominal ultrasound exams. Independently, subjects were evaluated by a blinded physician who determined a treatment plan as per usual practice. Follow-up was conducted 7-10 days after the initial visit. Analysis of ultrasound findings was performed to determine their relationship with outcome measures including need for unplanned hospital visits or admissions.

FINDINGS

A total of 2,186 children were screened during periods of national dengue outbreak in Cambodia in consecutive years 2018-2019, and 253 children met eligibility criteria. Results showed patients with gallbladder wall thickening (> 3·0 mm) who were discharged had a significantly more likely need for unplanned visit or hospitalization than those with normal gallbladder wall, 67% (95% CI 44 - 84) versus 17% (95% CI 12 - 24), p < 0.0001. Subjects with any abnormal ultrasound finding were more likely to be directly admitted versus discharged upon initial presentation, 62·2% (95% CI 46.1 - 76.0) versus 19.5% (95% CI 14.8 - 25.4), p < 0.0001.

INTERPRETATION

Point-of-care ultrasound findings, particularly gallbladder wall thickening, in suspected early dengue can help predict disease progression in ambulatory patients. Ultrasound has potential to help guide management of suspected dengue patients and resource management during periods of dengue outbreak.

FUNDING

Society for Academic Emergency Medicine Foundation.