Introduction Respiratory instability is frequently observed during pediatric procedural sedation. The aim of this trial was to estimate the impact of high‐flow nasal cannula (HFNC) therapy on respiratory stability during sedation for upper gastrointestinal tract endoscopy in children. Methods Prospective randomized controlled non‐blinded single‐center pilot trial. Children were randomly allocated to receive either HFNC (2 L/kg/min) or low‐flow nasal oxygen cannula (LFNC, standard care). FiO2 was titrated to maintain SpO2 94% to 98% in both groups. Primary outcome was the number of events of respiratory instability defined by prespecified criteria (hypoxia, hypercapnia, apnea). Secondary outcomes included type and duration of events, number of interventions to regain respiratory stability and cumulative doses of medication. Results Fifty children (mean age, 12.3 ± 3.1 years) were enrolled and treated with HFNC (n = 25) or LFNC (n = 25). Patient and intervention characteristics were not different in the two study groups, including total oxygen flow rate. Mean (SD) number of respiratory events in the HFNC group was 2.0 ± 1.9 events compared to 2.0 ± 1.4 events in the LFNC group (P = .65; 95% CI of difference, −1.0 to 1.0). There was no difference for any secondary outcome criteria, percentage of patients for any outcome criteria and no difference in the number of respiratory events or airway management maneuvers per patient between treatment groups. Conclusions HFNC did not increase respiratory stability in sedated children undergoing upper gastrointestinal tract endoscopy compared to LFNC.

Background: The population of children with chronic respiratory failure requiring long-term mechanical ventilation in the home has grown worldwide. The optimal choice from an increasing number of home ventilators commercialized for children is often challenging for the attending physicians. The aim of the present study was to compare the trigger performance of five pediatric bilevel home ventilators and one intensive care unit ventilator depending on circuit type and system leak. Methods:The trigger performances of the ventilators were compared in combination with all compatible circuits using a physical model of the lung with increasing system leak. The flow generator simulated the patient's breathing effort with flow rates of 2.7-6.4 L/min at a frequency of 30 breaths/min. All ventilators were set to deliver 16 cmH 2 O inspiratory pressure support and 4 cmH 2 O positive endexpiratory pressure.

Background: Inhomogeneous lung ventilation and pulmonary air leaks are common adverse effects of mechanical ventilation in preterm infants suffering from respiratory distress syndrome. We hypothesized that shortening of inspiratory times can improve the homogeneity of lung aeration. We assumed that ultrashort inspiratory times lead to a full build-up of pressure in regions with low compliance while maintaining incomplete filling of regions with high compliance. Methods: We connected a two-compartment model of the lung with different compliances of the two compartments to a neonatal ventilator. Pressures and flow rates were measured separately for each compartment at inspiratory times ranging from 0.1 to 0.8 s and various combinations of tidal volumes. Results: An inspiratory time of 0.8 s resulted in near total pressure equalization between the airway pressure and the two compartments, as 97% of the maximum applied peak pressure was reached in the low compliance compartment and 95% in the high compliance compartment. The distribution of the tidal volume was proportional to the compartment compliance. Ultrashort inspiratory times lowered the peak pressure and tidal volume in the high compliance compartment but maintained higher pressure and volume in the low compliance compartment. An inspiratory time of 0.2 s resulted in a peak pressure of 80% of peak airway pressure in the low compliance compartment and in 61% of peak airway pressure in the high compliance compartment (p < .001). Conclusion: Ventilation with ultrashort inspiratory times may improve homogeneity of air distribution in inhomogeneous lungs of ventilated preterm or term infants.