Reference values of diaphragmatic dimensions in healthy children aged 0-8 years.

Diaphragmatic thickness (Tdi) and diaphragm thickening fraction (dTF) are widely used parameters in ultrasound studies of the diaphragm in mechanically ventilated children, but normal values for healthy children are scarce. We determined reference values of Tdi and dTF using ultrasound in healthy children aged 0-8 years old and assessed their reproducibility. In a prospective, observational cohort, Tdi and dTF were measured on ultrasound images across four age groups comprising at least 30 children per group: group 1 (0-6 months), group 2 (7 months-1 year), group 3 (2-4 years) and group 4 (5-8 years). Ultrasound images of 137 healthy children were included. Mean Tdi at inspiration was 2.07 (SD 0.40), 2.09 (SD 0.40), 1.69 (SD 0.30) and 1.72 (SD 0.30) mm for groups 1, 2, 3 and 4, respectively. Mean Tdi at expiration was 1.64 (SD 0.30), 1.67 (SD 0.30), 1.38 (SD 0.20) and 1.42 (SD 0.20) mm for groups 1, 2, 3 and 4, respectively. Mean Tdi at inspiration and mean Tdi at expiration for groups 1 and 2 were significantly greater than those for groups 3 and 4 (both p < 0.001). Mean dTF was 25.4% (SD 10.4), 25.2% (SD 8.3), 22.8% (SD 10.9) and 21.3% (SD 7.1) for group 1, 2, 3 and 4, respectively. The intraclass correlation coefficients (ICC) representing the level of inter-rater reliability between two examiners performing the ultrasounds was 0.996 (95% CI 0.982-0.999). ICC of the inter-rater reliability between the raters in 11 paired assessments was 0.989 (95% CI 0.973-0.995).   Conclusion: Ultrasound measurements of Tdi and dTF were highly reproducible in healthy children aged 0-8 years.    Trial registration: ClinicalTrials.gov identifier (NCT number): NCT04589910. What is Known: • Diaphragmatic thickness and diaphragm thickening fraction are widely used parameters in ultrasound studies of the diaphragm in mechanically ventilated children, but normal values for healthy children to compare these with are scarce. What is New: • We determined normal values of diaphragmatic thickness and diaphragm thickening fraction using ultrasound in 137 healthy children aged 0-8 years old. The diaphragmatic thickness of infants up to 1 year old was significantly greater than that of children from 2 to 8 years old. Diaphragmatic thickness decreased with an increase in body surface area. These normal values in healthy children can be used to assess changes in respiratory muscle thickness in mechanically ventilated children.

Implementation of a nurse-driven ventilation weaning protocol in critically ill children: Can it improve patient outcome?

BACKGROUND: Critically ill children treated with invasive mechanical ventilation in a paediatric intensive care unit (PICU) may suffer from complications leading to prolonged duration of ventilation and PICU stay. OBJECTIVE: The objective of this study is to find out if the use of a nurse-driven ventilation weaning protocol in a PICU can shorten the duration of mechanical ventilation. METHODS: In a prospective, pretest-posttest implementation study, we implemented a nurse-driven ventilation weaning protocol and compared its outcomes with those of the usual physician-driven weaning. In the posttest period, nurses weaned the patients until extubation as per this protocol. The primary outcome was duration of ventilation. The secondary outcomes were length of PICU stay, reintubation rate, and compliance with the protocol (measured by use of the prescribed support mode). RESULTS: In total, 424 patients aged from 0 to 18 years (212 pretest and 212 posttest) were included; in both groups, the median age was 3 months. The median duration of ventilation did not differ significantly between the pretest and posttest periods: 42.5 h. (interquartile range, IQR 14.3-121.3) vs. 44.5 h (IQR 12.3-107.0), respectively; p = 0.589. In the posttest period, the PICU stay was nonsignificantly shorter: 5.5 days (IQR 2-11) vs. 7 days (IQR 3-14) in the pretest period; p = 0.432. Compliance with the prescribed support mode was significantly higher in the posttest period: 69.9% vs. 55.7% in the pretest period; p = 0.005. The reintubation rate was not significantly different between the pretest and posttest periods (5% vs. 7%, respectively; p = 0.418). The extubation rate during nights was higher in the posttest period but not significantly different (p = 0.097). CONCLUSIONS: Implementation of a nurse-driven weaning protocol did not result in a significantly shorter duration of invasive mechanical ventilation but was safe and successful. The reintubation rate did not significantly increase compared with usual care.

How to achieve adherence to a ventilation algorithm for critically ill children?

AIMS AND OBJECTIVES: To evaluate to what extent physicians on a paediatric intensive care unit (PICU) adhered to a newly implemented ventilation algorithm. BACKGROUND: PICUs worldwide use different ventilators with a wide variety of ventilation modes. We developed an algorithm, as part of a larger protocol, for choice of ventilation mode at time of admission. DESIGN: This study was performed in a level III PICU of a university children's hospital and had an uncontrolled, pre-post test design with a period before implementation (T0) and two periods after implementation (T1 and T2). METHODS: An invasive ventilation algorithm targeted at two patient groups was implemented in October 2008. The algorithm distinguished between lung disease, in which pressure control was considered as the preferred mode, and no lung disease, in which pressure-regulated volume control was preferred. Nurses and physicians were instructed in the use of the algorithm before implementation. RESULTS: During three test periods, a total of 507 children with a median age of 5 months [interquartile range (IQR) 0-50] on conventional invasive mechanical ventilation were included. In patients with lung disease, pre-implementation adherence rate was 79% (67/85). At T1 it was 71% (51/72); at T2 84% (46/55). The slight improvement from T1 to T2 was statistically not significant (p = 0·092). In patients with no lung disease, the adherence rate rose statistically significantly from 66% at T0 (62/93) to 78% (79/101) at T1, and 84% at T2 (85/101) (p = 0·015). CONCLUSION: Implementation of a new ventilation algorithm increased physicians' adherence to this ventilation algorithm and the effect was sustained over time. This was achieved by education, reminders and organizational changes such as admission of postcardiac surgery patients with protocolized nursing care including preset ventilator settings. RELEVANCE TO CLINICAL PRACTICE: Interdisciplinary collaboration, effective communication, leadership support and organizational aspects may be effective strategies to improve adherence to protocols.

Neurally adjusted ventilatory assist: assessing the comfort and feasibility of use in neonates and children.

AIM: To evaluate the practical feasibility for nurses working with neurally adjusted ventilatory assist (NAVA) and assess patient comfort and safety when NAVA is initiated. BACKGROUND: NAVA is a relatively new mode of ventilation. Its application in neonates and children has been widely documented. However, its practical feasibility from a nursing point of view as well as its safety and comfort in these populations compared with conventional modes of ventilation has not been described. DESIGN: A prospective, observational crossover pilot study. METHOD: NAVA was compared with the conventional mode of ventilation for 3 h each, and practical feasibility, patient comfort level and safety were assessed. RESULTS: Twenty-one neonates and children were enrolled into the study. There were no reported adverse events. In most patients, the NAVA catheter was placed too shallow, as measured by the distances from the nose, ear, xiphisternum (NEX) method, according to the manufacturer's instructions. Accurate placement was confirmed by visual inspection of the NAVA positioning window. Patients' comfort did not differ between the conventional mode and NAVA. CONCLUSIONS: NAVA is feasible, once an accurate signal of the electrical activity of the diaphragm is achieved and seems safe and well tolerated in both neonates and children. Nurses need to gain experience in placing the NAVA catheter and practical recommendations are given. RELEVANCE TO CLINICAL PRACTICE: NAVA is a promising new mode of ventilation. This article contributes to an increasing body of evidence that NAVA is feasible in neonates and children. There are practical considerations when NAVA is applied in these patient-groups.

No association between thickening fraction of the diaphragm and extubation success in ventilated children.

Introduction: In mechanically ventilated adults, thickening fraction of diaphragm (dTF) measured by ultrasound is used to predict extubation success. Whether dTF can also predict extubation success in children is unclear. Aim: To investigate the association between dTF and extubation success in children. Second, to assess diaphragm thickness during ventilation and the correlation between dTF, diaphragm thickness (Tdi), age and body surface. Method: Prospective observational cohort study in children aged 0-18 years old with expected invasive ventilation for >48 h. Ultrasound was performed on day 1 after intubation (baseline), day 4, day 7, day 10, at pre-extubation, and within 24 h after extubation. Primary outcome was the association between dTF pre-extubation and extubation success. Secondary outcome measures were Tdi end-inspiratory and Tdi end-expiratory and atrophy defined as <10% decrease of Tdi end-expiratory versus baseline at pre-extubation. Correlations were calculated with Spearman correlation coefficients. Inter-rater reliability was calculated with intraclass correlation (ICC). Results: Fifty-three patients, with median age 3.0 months (IQR 0.1-66.0) and median duration of invasive ventilation of 114.0 h (IQR 55.5-193.5), were enrolled. Median dTF before extubation with Pressure Support 10 above 5 cmH2O was 15.2% (IQR 9.7-19.3). Extubation failure occurred in six children, three of whom were re-intubated and three then received non-invasive ventilation. There was no significant association between dTF and extubation success; OR 0.33 (95% CI; 0.06-1.86). Diaphragmatic atrophy was observed in 17/53 cases, in three of extubation failure occurred. Children in the extubation failure group were younger: 2.0 months (IQR 0.81-183.0) vs. 3.0 months (IQR 0.10-48.0); p = 0.045. At baseline, pre-extubation and post-extubation there was no significant correlation between age and BSA on the one hand and dTF, Tdi- insp and Tdi-exp on the other hand. The ICC representing the level of inter-rater reliability between the two examiners performing the ultrasounds was 0.994 (95% CI 0.970-0.999). The ICC of the inter-rater reliability between the raters in 36 paired assessments was 0.983 (95% CI 0.974-0.990). Conclusion: There was no significant association between thickening fraction of the diaphragm and extubation success in ventilated children.

Invasive ventilation modes in children: a systematic review and meta-analysis.

INTRODUCTION: The purpose of the present study was to critically review the existing body of evidence on ventilation modes for infants and children up to the age of 18 years. METHODS: The PubMed and EMBASE databases were searched using the search terms 'artificial respiration', 'instrumentation', 'device', 'devices', 'mode', and 'modes'. The review included only studies comparing two ventilation modes in a randomized controlled study and reporting one of the following outcome measures: length of ventilation (LOV), oxygenation, mortality, chronic lung disease and weaning. We quantitatively pooled the results of trials where suitable. RESULTS: Five trials met the inclusion criteria. They addressed six different ventilation modes in 421 children: high-frequency oscillation (HFO), pressure control (PC), pressure support (PS), volume support (VS), volume diffusive respirator (VDR) and biphasic positive airway pressure. Overall there were no significant differences in LOV and mortality or survival rate associated with the different ventilation modes. Two trials compared HFO versus conventional ventilation. In the pooled analysis, the mortality rate did not differ between these modes (odds ratio = 0.83, 95% confidence interval = 0.30 to 1.91). High-frequency ventilation (HFO and VDR) was associated with a better oxygenation after 72 hours than was conventional ventilation. One study found a significantly higher PaO2/FiO2 ratio with the use of VDR versus PC ventilation in children with burns. Weaning was studied in 182 children assigned to either a PS protocol, a VS protocol or no protocol. Most children could be weaned within 2 days and the weaning time did not significantly differ between the groups. CONCLUSIONS: The literature provides scarce data for the best ventilation mode in critically ill children beyond the newborn period. There is no evidence, however, that high-frequency ventilation reduced mortality and LOV. Longer-term outcome measures such as pulmonary function, neurocognitive development, and cost-effectiveness should be considered in future studies.