[Pulmonary complications of sickle cell disease in children]. / Atteintes pulmonaires au cours de la drépanocytose chez l'enfant.

Acute and chronic pulmonary complications are frequent in sickle cell disease (SCD), with different spectrum and characteristics in children and adults. Chronic hypoxia is frequent and plays a role in several respiratory complications in SCD. Furthermore, hypoxia has been associated with a higher risk of cerebral ischemia. Despite differing oxygen affinity between hemoglobin A and S, standard pulse oximetry was shown to be accurate in diagnosing hypoxia in SCD patients. Whereas acute hypoxia management is similar to non-SCD patients, chronic hypoxia treatment is mainly based on a transfusion program rather than long-term oxygen therapy. Acute chest syndrome (ACS) is the foremost reason for admission to the intensive care unit and the leading cause of premature death. Guidelines on its management have recently been published. Asthma appears to be a different comorbidity and may increase the risk of vaso-occlusive crisis, ACS, and early death. Its management is not specific in SCD, but systemic steroids must be used carefully. Pulmonary hypertension (PH) is a major risk factor of death in adult patients. In children, no association between PH and death has been shown. Elevated tricuspid regurgitant velocity was associated with lower performance on the 6-min walk test (6MWT) but its long-term consequences are still unknown. These differences could be due to different pathophysiology mechanisms. Systematic screening is recommended in children. Regarding lung functions, although obstructive syndrome appears to be rare, restrictive pattern prevalence increases with age in SCD patients. Adaptation to physical exercise is altered in SCD children: they have a lower walking distance at the 6MWT than controls and can experience desaturation during effort, but muscular blood flow regulation maintains normal muscular strength. Sleeping disorders are frequent in SCD children, notably Obstructive sleep apnea syndrome (OSAS). Because of the neurological burden of nocturnal hypoxia, OSAS care is primordial and mainly based on adenotonsillectomy, which has been shown to reduce ischemic events. The high morbidity and mortality related to pulmonary impairments in SCD require a careful pulmonary assessment and follow-up. Mainly based on clinical examination, follow-up aims to the diagnosis of SCD-related respiratory complications early in these children.

[Premature infants bronchopulmonary dysplasia: past and present]. / Dysplasie bronchopulmonaire du nouveau-né prématuré : d'hier à aujourd'hui.

Bronchopulmonary dysplasia (BPD) is the most common chronic respiratory disease in premature infants. BPD was first described by Northway in 1967 as a chronic respiratory condition that developed in premature infants exposed to mechanical ventilation and high oxygen supplementation. DBP is currently defined by the need for supplemental oxygen at 28 days of life (mild BPD) and at the 36 weeks of post-menstrual age (moderate and severe BPD). With the advances of neonatal care, epidemiological characteristics and mechanisms of the disease as well as pathological characteristics and clinical course have profoundly changed within the last two decades, but still no effective curative treatment exists and BPD continue to occur among 10 to 20% of premature infants. Furthermore, BPD is a significant source of respiratory and neuro-cognitive morbidities. Thus, its treatment makes a considerable demand on health services. Regarding its pathophysiological mechanisms, it is now established that BPD is a complex disease combining genetic susceptibility and environmental injuries. The identification of genetic variants involved in BPD is a potential source of innovative development in terms of diagnosis and treatment. Indeed, no curative or effective prophylactic therapeutic exists and BPD treatment is currently symptomatic.

[Congenital cystic adenomatoid malformations of the lung: diagnosis, treatment, pathophysiological hypothesis]. / Malformations adénomatoïdes kystiques du poumon : diagnostic, prise en charge, hypothèses physiopathologiques.

Congenital cystic adenomatoid malformations (CCAM) of the lung are the most frequent congenital lung malformations. Their diagnosis is based on histological features. CCAM consist of bronchopulmonary cystic lesions which are classified according to the presence and cysts size. Type I CCAM are composed of large cysts (>2 cm) lined by a columnar pseudostratified epithelium. Type II CCAM contain multiple small cystic lesions (<1 cm) lined by a flattened cuboidal epithelium. Type III CCAM are more solid and contain immature structures resembling the pseudoglandular stage of lung development. Ultrasonography (US) allows early detection during the second trimester of pregnancy as cystic, and/or hyperechoic fetal lung lesions. Although most CCAM remain asymptomatic, CCAM can cause polyhydramnios or fetal hydrops, respiratory distress at birth, infections and pneumothoraces during infancy, and may give rise to malignancies. Serial US allow detection of complications, and planification of delivery. Complicated forms require an urgent treatment. In fetuses with a macrocystic life-threatening lesion, a thoraco-amniotic shunt can be placed. Microcystic compressive forms may respond to prenatal steroids. Post-natal symptomatic lesions require early surgery. The treatment of asymptomatic forms remains controversial. Some recommend a non-operative approach with a long-term clinical and radiological following, whereas other favour a preventive surgical excision. The origin of CCAM remains unknown. Recent advances suggest a transient and focal abnormality in lung development which may result from an airway obstruction. This article reviews the diagnosis, treatment, and pathophysiology of CCAM.

Factors associated with partial and complete regression of fetal lung lesions.

OBJECTIVE: A decrease in the volume of congenital pulmonary malformations (CPM) can be observed on prenatal ultrasonography, but the underlying mechanism for this phenomenon is unknown. Our objective was to identify factors associated with the prenatal reduction in size of cystic and/or hyperechoic lung lesions. METHODS: This was a retrospective study of cases with a prenatal diagnosis of hyperechoic and/or cystic lung lesion. The extent of reduction in lesion size was calculated from ultrasound measurements. Clinical, ultrasound, radiological and histological data were tested for their relationship with prenatal CPM reduction. RESULTS: In a 4-year period, 36 patients were referred with a cystic and/or hyperechoic fetal lung lesion diagnosed at a mean gestational age of 23.4 weeks. The lesions were cystic in 16 cases (44%), hyperechoic in 12 (33%) and both in eight (22%). The malformation was no longer visible before birth (apparent disappearance) in nine cases (25%), shrank by 18-90% in 15 (42%) and did not reduce in 12 (33%). Findings on postnatal computed tomography were always abnormal. Isolated hyperechoic lesions were significantly more likely to shrink in utero. The mean reductions were 79%, 35% and 19%, for isolated hyperechoic, cystic and mixed lesions, respectively (P=0.001). Only 8% of hyperechoic lesions demonstrated no volume reduction, as compared to 50% and 42% of cystic and mixed lesions, respectively (P=0.03). Greater gestational age at birth was also associated with a decrease in the incidence of malformations (P=0.02). In cases that underwent surgery, hyperechoic lesions were linked to a variety of pathological diagnoses, whereas cystic lesions were all described histologically as congenital cystic adenomatoid malformations. CONCLUSIONS: Prenatal size reduction of fetal lung malformations is associated with isolated hyperechogenicity and greater gestational age at birth. This might result from the resumption of normal lung development after local disruption of lung growth.