Objective:To explore the reproducibility of ultrasound measurements of children′s anterior, middle and posterior diaphragm motions.Methods:Thirty children admitted to a pediatric intensive care unit were positioned supine and a 5MHz ultrasound probe was placed over the intersection of their right midclavicular line with the costal margin. M-mode ultrasound was used to record the excursion and contraction velocity of the anterior, middle and posterior diaphragm during respiration. The observations were duplicated so the repeatability of the measurements could be evaluated using intra-group correlation coefficients calculated for the diaphragm excursions and the contraction velocities. Analysis of variance was used to explore the differences in excursion and contraction velocity among different parts of the diaphragm.Results:The intra-group correlation coefficients calculated for the anterior, middle and posterior diaphragm were 0.89, 0.95 and 0.90 respectively. The corresponding values for the contraction velocities were 0.90, 0.94 and 0.95 respectively. Both variables measured by ultrasound showed high repeatability. The average anterior, middle and posterior diaphragm excursion values (in mm) were 8.1±3.1, 7.4±3.0 and 5.5±2.3, and the corresponding average contraction velocities (in mm/s) were 12.5±4.8, 11.5±6.3 and 8.9±4.0.Conclusions:Measurements of children′s diaphragm motions using ultrasound show high repeatability. The excursions and contraction velocities of the anterior, middle and posterior diaphragm differ in children. The motion of one part of the diaphragm cannot represent the functioning of the entire diaphragm.

Rehabilitation and multidisciplinary team management are very important to improve the prognosis of children with prolonged mechanical ventilation(PMV). The current status of rehabilitation intervention including physical therapy, neuromuscular electrical stimulation and inspiratory muscle training in adult patients with PMV were discussed, aiming to provide some evidence for the implementation of rehabilitation in children with PMV.

Objective:To explore the effects of external diaphragm electrical stimulation on the diaphragm thickness and function in mechanically ventilated children.Methods:A randomized controlled trial was conducted in children who were admitted to PICU at Children′s Hospital of Fudan University and received mechanical ventilation between June 2021 and April 2022.The control group was given the routine treatment of mechanical ventilation, and the intervention group was given external diaphragm electrical stimulation in the early stage of mechanical ventilation in addition to routine treatment.Diaphragm thickness was continuously measured by bedside ultrasound every day for one week after mechanical ventilation, and the changing trend of diaphragm thickness was observed, and the diaphragmatic thickening fraction (DTf) and the incidence of ventilator-induced diaphragmtic dysfunction(VIDD) were calculated at the same time.Results:A total of 32 valid samples were included, including 15 cases in intervention group (10 males) and 17 cases in control group (11 males). The median age of the patients was 33 (10, 77) months, and the median duration of mechanical ventilation was 12 (8, 21) days.The reasons for mechanical ventilation in children included respiratory insufficiency in ten cases, brain dysfunction in ten cases, heart failure in eight cases, and postoperative surgery in four cases.The diaphragm end-expiratory thickness (DTe) in intervention group and the control group showed a gradually decreasing trend from the 1st day to the 7th day.The left thickness was reduced by 11% on the 7th day compared to 1st day in intervention group, which was reduced by 18% in control group; the average daily DTe was reduced by 2% per day in intervention group and by 3% per day in control group.The trends on the right and left were similar.The DTe thickness in the intervention group was greater than that in control group, among which, the mean DTe thickness in the left side of the intervention group on the 7th day was (0.110 7±0.023 7)cm, which was greater than that in control group (0.093 5±0.016 9)cm, and the difference was statistically significant ( t=-2.372, P<0.05); On the second day, the mean DTe thickness on the right side in the intervention group was (0.1267±0.0277) cm, which was greater than that in control group (0.104 7±0.018 1)cm, and the difference was statistically significant ( t=-2.688, P<0.05). DTf in the intervention group was lower than that in control group at 7th day, but the difference was not statistically significant(left DTf: adjusted mean difference was -0.117, P=0.088; right DTf: adjusted mean difference was -0.065, P=0.277). The incidence of VIDD in the intervention group was lower than that in control group(33.3% vs.41.2%), but the difference was not statistically significant ( χ2=0.005, P=0.946). Conclusion:External diaphragmatic electrical stimulation may be helpful for alleviating diaphragmatic atrophy in mechanically ventilated children.However, whether the improvement of diaphragm atrophy is beneficial to clinical outcome still needs further study.