Use of dual genomic sequencing to screen mitochondrial diseases in pediatrics: a retrospective analysis.

Mitochondrial diseases (MDs) were a large group multisystem disorders, attributable in part to the dual genomic control. The advent of massively sequencing has improved diagnostic rates and speed, and was increasingly being used as a first-line diagnostic test. Paediatric patients (aged < 18 years) who underwent dual genomic sequencing were enrolled in this retrospective multicentre study. We evaluated the mitochondrial disease criteria (MDC) and molecular diagnostic yield of dual genomic sequencing. Causative variants were identified in 177 out of 503 (35.2%) patients using dual genomic sequencing. Forty-six patients (9.1%) had mitochondria-related variants, including 25 patients with nuclear DNA (nDNA) variants, 15 with mitochondrial DNA (mtDNA) variants, and six with dual genomic variants (MT-ND6 and POLG; MT-ND5 and RARS2; MT-TL1 and NARS2; MT-CO2 and NDUFS1; MT-CYB and SMARCA2; and CHRNA4 and MT-CO3). Based on the MDC, 15.2% of the patients with mitochondria-related variants were classified as "unlikely to have mitochondrial disorder". Moreover, 4.5% of the patients with non-mitochondria-related variants and 1.43% with negative genetic tests, were classified as "probably having mitochondrial disorder". Dual genomic sequencing in suspected MDs provided a more comprehensive and accurate diagnosis for pediatric patients, especially for patients with dual genomic variants.

Methylprednisolone pulse therapy rescued life-threatening pulmonary hemorrhage due to idiopathic pulmonary hemosiderosis.

Idiopathic pulmonary hemosiderosis (IPH) is an extremely rare cause of massive pulmonary hemorrhage in children. During the acute phase, death due to massive alveolar hemorrhage and subsequent severe respiratory failure. We report two cases of IPH children who developed hypoxemic respiratory failure and massive pulmonary hemorrhage. One case of a 10-year-old boy was treated with methylprednisolone pulse therapy (10mg/kg/d) for the first three days and followed by systemic steroid therapy, he successfully decannulated 10days later and discharged with a favorable quality of life. Another case of a 4year-old female child with Down's syndrome diagnosed as IPH for over one year and treated with oral corticosteroids for maintenance therapy. She sudden suffered severe hypoxemia with rapid falls in the hemoglobin level. We applied methylprednisolone pulse therapy (10mg/kg/d) for three days and other supportive therapies, the girl survived through complicated with oxygen dependence. We suggest that methylprednisolone pulse therapy provides a chance of recovery and survival for patients with IPH at the acute phase, even if accompanied by severe pulmonary hemorrhage.

High-frequency oscillatory ventilation is an effective treatment for severe pediatric acute respiratory distress syndrome with refractory hypoxemia.

BACKGROUND AND PURPOSE: Early or primary application of high-frequency oscillatory ventilation (HFOV) has been recently suggested not to offer benefit to patients with acute respiratory distress syndrome (ARDS). However, the rescue effects of HFOV on severe pediatric acute respiratory distress syndrome (PARDS) with hypoxemia refractory to conventional mechanical ventilation (CMV) remain unclear. This study aimed to determine whether severe PARDS children would benefit from HFOV when oxygenation deteriorated on CMV and to identify any potential risk factors related to mortality. PATIENTS AND METHODS: In a retrospective and observational study, 48 children with severe PARDS between January 2009 and July 2015 were divided into two groups: 26 in HFOV group and 22 in CMV group. Data regarding demographic, underlying conditions, arterial blood gases and clinical outcomes were collected and analyzed. RESULTS: The arterial partial pressure of oxygen (PaO2)/fraction of inspiration oxygen (FiO2) ratio and PaO2 improved significantly during HFOV, whereas arterial partial pressure of carbon dioxide (PaCO2) and oxygenation index decreased. There was no statistical difference in the in-hospital mortality between the groups (P=0.367). The odds ratio of survival in HFOV group was 2.74 (95% confidence interval 0.52 to 14.58, P=0.237). The pediatric intensive care unit length of stay and total ventilation duration were longer in HFOV group (P=0.048 and P=0.000, respectively). Vasoactive agents were used more frequently in HFOV group (P=0.007). The incidence of new air leak was similar between the two groups (P=0.674). The presence of multiple organ dysfunction syndrome and heavier body weight were identified as predictors of mortality in the HFOV group (P=0.006 and P=0.020, respectively). CONCLUSION: HFOV as an efficient alternative therapy could significantly improve hypoxemia and promote CO2 removal in severe PARDS children when oxygenation progressively worsens on CMV.