Pulmonary Ultrasound in the Diagnosis of Acute Thoracic Syndrome in Vaso-occlusive Sickle Cell Crisis

Study Overview
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Brief Summary
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ATS (acute thoracic syndrome) refers to acute pulmonary involvement in a sickle cell patient. The diagnosis is based on the association of clinical signs (fever or respiratory symptoms) with a recent pulmonary infiltrate on the chest x-ray. The main objective of the study is to evaluate the place of the pulmonary ultrasound for the diagnosis of ATS, in comparison with frontal chest x-ray.

Detailed Description
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The ATS occurs in half of the cases during hospitalization for a VOC (Vaso Occlusive crisis). The morbidity of ATS is important (respiratory insufficiency, duration of hospitalization, stays in intensive care, brain complications, pain, hypoxia, long-term sequelae, etc.) but no study has shown the benefits of curative treatments such as transfusion ( recommended at the time of diagnosis and practiced by some teams) or noninvasive ventilation (practiced by other teams). The first step before studying curative treatments is to have tools for early detection of ATS. Recent studies show non-inferiority of pulmonary ultrasonography compared to radiography and thoracic computed tomography in the diagnosis of pulmonary condensation (in adults and children). In a study performed in sickle cell adults admitted for ATS, pulmonary ultrasound was more sensitive than X-ray in detecting images of pulmonary consolidations visible on the chest CT scan. Daswani et al have also shown the value of pulmonary ultrasound in comparison with radiography in the detection of consolidation lesions, suggestive of STA, in febrile children or young adults with sickle cell disease. They showed a good sensitivity (87%) and specificity (94%) of the pulmonary ultrasound.

Official Title
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Evaluation of the Interest of Pulmonary Ultrasound in the Diagnosis and Early Detection of Acute Thoracic Syndrome in Hospitalized Children for Vaso-occlusive Sickle Cell Crisis: Multicenter Prospective Study

Conditions
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Sickle-Cell Disease Nos With Crisis

Intervention / Treatment
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* Diagnostic Test: pulmonary ultrasound


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age: ≥12 months and <18 years Has a major sickle cell disease whatever the genotype Admission to hospital for a febrile vaso-occlusive crisis (VOC) or not Evolving at home for less than 48h Concomitant treatment with hydroxycarbamide / hydroxyurea possible Signed consent Patients affiliated to a French social security scheme Exclusion Criteria: Child presenting an acute thoracic syndrome (ATS) from the outset at the admission Child who presented an ATS in the month preceding the inclusion Child in regular transfusion program or child who has received a hematopoietic stem cell transplant Child hospitalized at least 5 times for VOC in the year preceding inclusion (psychic problems making difficult the evaluation of the pain) Child who has already been included in the study during a previous VOC (each child participates in the study only once) VOC evolving for more than 48 hours before admission to the emergency room Acute splenic sequestration crisis at admission

Ages Eligible for Study
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Minimum Age: 12 Months
Maximum Age: 17 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Diagnostic
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Children with sickle cell disease<br>Child from 12 months to 18 years old admitted for vaso-occlusive crisis | Diagnostic Test: pulmonary ultrasound<br>* The subjects will have an ultrasound on admission and on day 1, 2 and 3<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Sensitivity of pulmonary ultrasound | Proportion of subjects with positive pulmonary ultrasound among those with a positive chest X-ray at time t with 95% confidence interval at day 1 | Day 1 | 
| Sensitivity of pulmonary ultrasound | Proportion of subjects with positive pulmonary ultrasound among those with a positive chest X-ray at time t with 95% confidence interval at day 2 | Day 2 | 
| Sensitivity of pulmonary ultrasound | Proportion of subjects with positive pulmonary ultrasound among those with a positive chest X-ray at time t with 95% confidence interval at day 3 | Day 3 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Specificity of pulmonary ultrasound | Proportion of subjects with a positive pulmonary ultrasound among those with a negative chest X-ray at time t at day 1 | Day 1 | 
| Specificity of pulmonary ultrasound | Proportion of subjects with a positive pulmonary ultrasound among those with a negative chest X-ray at time t at day 2 | Day 2 | 
| Specificity of pulmonary ultrasound | Proportion of subjects with a positive pulmonary ultrasound among those with a negative chest X-ray at time t at day 3 | Day 3 | 
| Sensitivity of pulmonary ultrasound in relation with ATS diagnosis | Proportion of subjects with positive pulmonary ultrasound among those with a positive chest X-ray at time t with 95% confidence intervalat day -3 of ATS diagnosis | day -3 of ATS diagnosis | 
| Sensitivity of pulmonary ultrasound in relation with ATS diagnosis | Proportion of subjects with positive pulmonary ultrasound among those with a positive chest X-ray at time t with 95% confidence interval at day -1 of ATS diagnosis | day -1 of ATS diagnosis | 
| Sensitivity of pulmonary ultrasound in relation with ATS diagnosis | Proportion of subjects with positive pulmonary ultrasound among those with a positive chest X-ray at time t with 95% confidence interval at day -2 of ATS diagnosis | day -2 of ATS diagnosis | 
| Specificity of pulmonary ultrasound in relation with ATS diagnosis | Proportion of subjects with a positive pulmonary ultrasound among those with a negative chest X-ray at time t at day -1 of ATS diagnosis | day -1 of ATS diagnosis | 
| Specificity of pulmonary ultrasound in relation with ATS diagnosis | Proportion of subjects with a positive pulmonary ultrasound among those with a negative chest X-ray at time t at day -3 of ATS diagnosis | -3 day of ATS diagnosis | 
| Specificity of pulmonary ultrasound in relation with ATS diagnosis | Proportion of subjects with a positive pulmonary ultrasound among those with a negative chest X-ray at time t at day -2 of ATS diagnosis | day -2 of ATS diagnosis |