Hemodynamic Effects of a High-Frequency Oscillatory Ventilation Open-Lung Strategy in Critically Ill Children With Acquired or Congenital Cardiac Disease

OBJECTIVES: To study the hemodynamic consequences of an open-lung high-frequency oscillatory ventilation (HFOV) strategy in patients with an underlying cardiac anomaly with or without intracardiac shunt or primary pulmonary hypertension with severe lung injury.DESIGN: Secondary analysis of prospectively collected data.SETTING: Medical-surgical PICU.PATIENTS: Children less than 18 years old with cardiac anomalies (± intracardiac shunt) or primary pulmonary hypertension.INTERVENTIONS: None.MEASUREMENTS AND MAIN RESULTS: Data from 52 subjects were analyzed, of whom 39 of 52 with cardiac anomaly (23/39 with intracardiac shunt) and 13 of 52 with primary pulmonary hypertension. Fourteen patients were admitted postoperatively, and 26 patients were admitted with acute respiratory failure. Five subjects (9.6%) were canulated for ECMO (of whom four for worsening respiratory status). Ten patients (19.2%) died during PICU stay. Median conventional mechanical ventilation settings prior to HFOV were peak inspiratory pressure 30 cm H 2 O (27-33 cm H 2 O), positive end-expiratory pressure 8 cm H 2 O (6-10 cm H 2 O), and F io2 0.72 (0.56-0.94). After transitioning to HFOV, there was no negative effect on mean arterial blood pressure, central venous pressure, or arterial lactate. Heart rate decreased significantly over time ( p &lt; 0.0001), without group differences. The percentage of subjects receiving a fluid bolus decreased over time ( p = 0.003), especially in those with primary pulmonary hypertension ( p = 0.0155) and without intracardiac shunt ( p = 0.0328). There were no significant differences in the cumulative number of daily boluses over time. Vasoactive Infusion Score did not increase over time. Pa co2 decreased ( p &lt; 0.0002) and arterial pH significantly improved ( p &lt; 0.0001) over time in the whole cohort. Neuromuscular blocking agents were used in all subjects switched to HFOV. Daily cumulative sedative doses were unchanged, and no clinically apparent barotrauma was found.CONCLUSIONS: No negative hemodynamic consequences occurred with an individualized, physiology-based open-lung HFOV approach in patients with cardiac anomalies or primary pulmonary hypertension suffering from severe lung injury.</p

Trends in Pediatric Patient-Ventilator Asynchrony During Invasive Mechanical Ventilation

OBJECTIVES: To explore the level and time course of patient-ventilator asynchrony in mechanically ventilated children and the effects on duration of mechanical ventilation, PICU stay, and Comfort Behavior Score as indicator for patient comfort.DESIGN: Secondary analysis of physiology data from mechanically ventilated children.SETTING: Mixed medical-surgical tertiary PICU in a university hospital.PATIENTS: Mechanically ventilated children 0-18 years old were eligible for inclusion. Excluded were patients who were unable to initiate and maintain spontaneous breathing from any cause.MEASUREMENTS AND MAIN RESULTS: Twenty-nine patients were studied with a total duration of 109 days. Twenty-two study days (20%) were excluded because patients were on neuromuscular blockade or high-frequency oscillatory ventilation, yielding 87 days (80%) for analysis. Patient-ventilator asynchrony was detected through analysis of daily recorded ventilator airway pressure, flow, and volume versus time scalars. Approximately one of every three breaths was asynchronous. The percentage of asynchronous breaths significantly increased over time, with the highest prevalence on the day of extubation. There was no correlation with the Comfort Behavior score. The percentage of asynchronous breaths during the first 24 hours was inversely correlated with the duration of mechanical ventilation. Patients with severe patient-ventilator asynchrony (asynchrony index &gt; 10% or &gt; 75th percentile of the calculated asynchrony index) did not have a prolonged duration of ventilation.CONCLUSIONS: The level of patient-ventilator asynchrony increased over time was not related to patient discomfort and inversely related to the duration of mechanical ventilation.</p

Pulmonary Specific Ancillary Treatment for Pediatric Acute Respiratory Distress Syndrome:From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES: We conducted an updated review of the literature on pulmonary-specific ancillary therapies for pediatric acute respiratory distress syndrome (PARDS) to provide an update to the Pediatric Acute Lung Injury Consensus Conference recommendations and statements about clinical practice and research. DATA SOURCES: MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost). STUDY SELECTION: Searches were limited to children, PARDS or hypoxic respiratory failure and overlap with pulmonary-specific ancillary therapies DATA EXTRACTION: Title/abstract review, full-text review, and data extraction using a standardized data collection form. DATA SYNTHESIS: The Grading of Recommendations Assessment, Development, and Evaluation approach was used to identify and summarize evidence and develop recommendations. Twenty-six studies were identified for full-text extraction. Four clinical recommendations were generated, related to use of inhaled nitric oxide, surfactant, prone positioning, and corticosteroids. Two good practice statements were generated on the use of routine endotracheal suctioning and installation of isotonic saline prior to endotracheal suctioning. Three research statements were generated related to: the use of open versus closed suctioning, specific methods of airway clearance, and various other ancillary therapies. CONCLUSIONS: The evidence to support or refute any of the specific ancillary therapies in children with PARDS remains low. Further investigation, including a focus on specific subpopulations, is needed to better understand the role, if any, of these various ancillary therapies in PARDS.</p

Early Neuromuscular Blockade in Moderate-to-Severe Pediatric Acute Respiratory Distress Syndrome

Objectives: The use of neuromuscular blocking agents (NMBAs) in pediatric acute respiratory distress syndrome (PARDS) is common but unsupported by efficacy data. We sought to compare the outcomes between patients with moderate-to-severe PARDS receiving continuous NMBA during the first 48 hours of endotracheal intubation (early NMBA) and those without. Design: Secondary analysis of data from the Randomized Evaluation of Sedation Titration for Respiratory Failure (RESTORE) clinical trial, a pediatric multicenter cluster randomized trial of sedation. Setting: Thirty-one PICUs in the United States. Patients: Children 2 weeks to 17 years receiving invasive mechanical ventilation (MV) for moderate-to-severe PARDS (i.e., oxygenation index >= 8 and bilateral infiltrates on chest radiograph on days 0-1 of endotracheal intubation). Interventions: NMBA for the entire duration of days 1 and 2 after intubation. Measurements and Main Results: Among 1,182 RESTORE patients with moderate-to-severe PARDS, 196 (17%) received early NMBA for a median of 50.0% ventilator days (interquartile range, 33.3-60.7%). The propensity score model predicting the probability of receiving early NMBA included high-frequency oscillatory ventilation on days 0-2 (odds ratio [OR], 7.61; 95% CI, 4.75-12.21) and severe PARDS on days 0-1 (OR, 2.16; 95% CI, 1.50-3.12). After adjusting for risk category, early use of NMBA was associated with a longer duration of MV (hazard ratio, 0.57; 95% CI, 0.48-0.68; p < 0.0001), but not with mortality (OR, 1.62; 95% CI, 0.92-2.85; p = 0.096) compared with no early use of NMBA. Other outcomes including cognitive, functional, and physical impairment at 6 months post-PICU discharge were similar. Outcomes did not differ when comparing high versus low NMBA usage sites or when patients were stratified by baseline PaO2/FIO2 less than 150. Conclusions: Early NMBA use was associated with a longer duration of MV. This propensity score analysis underscores the need for a randomized controlled trial in pediatrics

Current practices in children with severe acute asthma across European PICUs: an ESPNIC survey

Most pediatric asthma guidelines offer evidence-based or best practice approaches to the management of asthma exacerbations but struggle with evidence-based approaches for severe acute asthma (SAA). We aimed to investigate current practices in children with SAA admitted to European pediatric intensive care units (PICUs), in particular, adjunct therapies, use of an asthma severity score, and availability of a SAA guideline. We designed a cross-sectional electronic survey across European PICUs. Thirty-seven PICUs from 11 European countries responded. In 8 PICUs (22%), a guideline for SAA management was unavailable. Inhaled beta-agonists and anticholinergics, combined with systemic steroids and IV MgSO4 was central in SAA treatment. Seven PICUs (30%) used a loading dose of a short-acting beta-agonist. Eighteen PICUs (49%) used an asthma severity score, with 8 different scores applied. Seventeen PICUs (46%) observed an increasing trend in SAA admissions. Conclusion: Variations in the treatment of children with SAA mainly existed in the use of adjunct therapies and asthma severity scores. Importantl

The effect of pressure support on imposed work of breathing during paediatric extubation readiness testing

BACKGROUND: Paediatric critical care practitioners often make use of pressure support (PS) to overcome the perceived imposed work of breathing (WOBimp) during an extubation readiness test (ERT). However, no paediatric data are available that shows the necessity of adding of pressure support during such tests. We sought to measure the WOBimp during an ERT with and without added pressure support and to study its clinical correlate. This was a prospective study in spontaneously breathing ventilated children < 18 years undergoing ERT. Using tracheal manometry, WOBimp was calculated by integrating the difference between positive end-expiratory pressure (PEEP) and tracheal pressure (Ptrach) over the measured expiratory tidal volume (VTe) under two paired conditions: continuous positive airway pressure (CPAP) with and without PS. Patients with post-extubation upper airway obstruction were excluded. RESULTS: A total of 112 patients were studied. Median PS during the ERT was 10 cmH2O. WOBimp was significantly higher without PS (median 0.27, IQR 0.20-0.50 J/L) than with added PS (median 0.00, IQR 0.00-0.11 J/L). Although there were statistically significant changes in spontaneous breath rate [32 (23-42) vs. 37 (27-46) breaths/min, p < 0.001] and higher ET-CO2 [5.90 (5.38-6.65) vs. 6.23 (5.55-6.94) kPa, p < 0.001] and expiratory Vt decreased [7.72 (6.66-8.97) vs. 7.08 (5.82-8.08) mL/kg, p < 0.001] in the absence of PS, these changes appeared clinically irrelevant since the Comfort B score remained unaffected [12 (10-13) vs. 12 (10-13), P = 0.987]. Multivariable analysis showed that changes in WOBimp occurred independent of endotracheal tube size. CONCLUSIONS: Withholding PS during ERT does not lead to clinically relevant increases in WOBimp, irrespective of endotracheal tube size