SignificanceMaintaining low CO2 levels in our bodies is critical for life and depends on neurons that generate the respiratory rhythm and monitor tissue gas levels. Inadequate response to increasing levels of CO2 is common in congenital hypoventilation diseases. Here, we identified a mutation in LBX1, a homeodomain transcription factor, that causes congenital hypoventilation in humans. The mutation alters the C terminus of the protein without disturbing its DNA-binding domain. Mouse models carrying an analogous mutation recapitulate the disease. The mutation spares most Lbx1 functions, but selectively affects development of a small group of neurons central in respiration. Our work reveals a very unusual pathomechanism, a mutation that hampers a small subset of functions carried out by a transcription factor.

Background: A study was undertaken to evaluate the efficacy of dexamethasone in patients mechanically ventilated for lower respiratory infection caused by respiratory syncytial virus (RSV-LRTI). Methods: In a multicentre randomised controlled trial patients were randomised to receive either intravenous dexamethasone (0.15 mg/kg 6 hourly for 48 hours) or placebo. End points were the duration of mechanical ventilation, length of stay (LOS) in the pediatric intensive care unit (PICU) and in hospital, and the duration of supplemental oxygen administration. Results: Thirty seven patients received dexamethasone and 45 received placebo. There was no significant difference in any of the end points between the two groups. In a post hoc analysis patients were stratified into those with mild gas exchange anomalies (PaO 2 /FiO 2 >200 mm Hg and/or mean airway pressure < 10 cm H 2 O, bronchiolitis group) and those with severe gas exchange anomalies (PaO 2 /FiO 2 <200 mm Hg and mean airway pressure >10 cm H 2 O, pneumonia group). In the 39 patients with bronchiolitis the duration of mechanical ventilation was 4.3 days shorter in the dexamethasone group than in the placebo group (4.9 v 9.2 days, 95% CI -7.8 to -0.8, p=0.02) and the duration of supplemental oxygen was 3.6 days shorter (7.7 v 11.3 days, 95% CI -8.0 to -0.1, p=0.048). No differences in end points were found in the pneumonia group. Conclusions: Dexamethasone had no beneficial effect in patients mechanically ventilated for RSV-LRTI but was found to have a beneficial effect in patients with bronchiolitis.

Parents', physicians', and nurses' perceptions of suffering overlap but also show important differences. Differences found seem to be rooted in the relation to and kind of responsibility (parental/professional) for the child. The child's illness, suffering, and hospital admission cause suffering in parents. Health-care professionals in PICUs need to be aware of these phenomena.

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