Risk Factors for Pediatric Extubation Failure: The Importance of Respiratory Muscle Strength

Air leak test in the Paediatric Intensive Care Unit (ALTIPICU): rationale and protocol for a prospective multicentre observational study

INTRODUCTION

In children, respiratory distress due to upper airway obstruction (UAO) is a common complication of extubation. The quantitative cuff-leak test (qtCLT) is a simple, rapid and non-invasive test that has not been extensively studied in children. The objective of the ongoing study whose protocol is reported here is to investigate how well the qtCLT predicts UAO-related postextubation respiratory distress in paediatric intensive care unit (PICU) patients.

METHODS AND ANALYSIS

Air Leak Test in the Paediatric Intensive Care Unit is a multicentre, prospective, observational study that will recruit 900 patients who are aged 2 days post-term to 17 years and ventilated through a cuffed endotracheal tube for at least 24 hours in any of 19 French PICUs. Within an hour of planned extubation, the qtCLT will be performed as a sequence of six measurements of the tidal volume with the cuff inflated then deflated. The primary outcome is the occurrence within 48 hours after extubation of severe UAO defined as combining a requirement for intravenous corticosteroid therapy and/or ventilator support by high-flow nasal cannula and/or by non-invasive ventilation or repeat invasive mechanical ventilation with a Westley score ≥4 with at least one point for stridor at each initiation. The results of the study are expected to identify risk factors for UAO-related postextubation respiratory distress and extubation failure, thereby identifying patient subgroups most likely to require preventive interventions. It will also determine whether qtCLT appears to be a reliable method to predict an increased risk for postextubation adverse events as severe UAO.

ETHICS AND DISSEMINATION

The study was approved by the Robert Debré University Hospital institutional review board (IRB) on September 2021 (approval #2021578). The report of Robert Debré University Hospital IRB is valid for all sites, given the nature of the study with respect to the French law. The results will be submitted for publication in a peer-reviewed journal.

TRIAL REGISTRATION NUMBER

NCT05328206.

Development of a clinical prediction tool for extubation failure in pediatric cardiac intensive care unit

Introduction/objective

Extubation failure in pediatric patients with congenital or acquired heart diseases increases morbidity and mortality. This study aimed to develop a clinical risk score for predicting extubation failure to guide proper clinical decision-making and management.

Methods

We conducted a retrospective study. This clinical prediction score was developed using data from the Pediatric Cardiac Intensive Care Unit (PCICU) of the Faculty of Medicine, Chiang Mai University, Thailand, from July 2016 to May 2022. Extubation failure was defined as the requirement for re-intubation within 48 h after extubation. Multivariable logistic regression was used for modeling. The score was evaluated in terms of discrimination and calibration.

Results

A total of 352 extubation events from 270 patients were documented. Among these, 40 events (11.36%) were extubation failure. Factors associated with extubation failure included history of pneumonia (OR: 4.14, 95% CI: 1.83-9.37, p = 0.001), history of re-intubation (OR: 5.99, 95% CI: 2.12-16.98, p = 0.001), and high saturation in physiologic cyanosis (OR: 5.94, 95% CI: 1.87-18.84, p = 0.003). These three factors were utilized to develop the risk score. The score showed acceptable discrimination with an area under the curve (AUC) of 0.77 (95% CI: 0.69-0.86), and good calibration.

Conclusion

The derived Pediatric CMU Extubation Failure Prediction Score (Ped-CMU ExFPS) could satisfactorily predict extubation failure in pediatric cardiac patients. Employing this score could promote proper personalized care. We suggest conducting further external validation studies before considering implementation in practice.

Clinical Variables Specific to Timing of Tracheal Extubation Following Pediatric Cardiac Surgery

BACKGROUND

The primary objective of this study was to identify specific factors in pediatric cardiac surgical patients when tracheal extubation was performed on the operating table after completion of open-heart surgery (Group-1), postoperatively in the intensive care unit within 6 h (Group-II) or after 6 h (Group-III). The causes of failed extubation, the presence of chromosomal disorders in addition to arterial blood gas analysis parameters at the time of tracheal extubation, and the duration of intensive care unit stay were also evaluated in each group.

METHODS

In addition to the three groups, Groups I and II were combined as a "fast-track" extubation group. The demographic data, Risk Adjustment for Congenital Heart Surgery (RACHS-1) score, the Society of Thoracic Surgeons - European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Category (STAT Mortality Category), cardiopulmonary bypass (CPB) time, aortic cross-clamp (ACC) time, and vasoactive-inotropic score (VIS) at the time of tracheal extubation along with data related to secondary objectives were recorded for each patient.

RESULTS

A significant association was found by bivariate analysis between clinical variables and for both operating table and fast-track extubation in terms of age, weight, RACHS-1 score, STAT category, CPB and ACC time, and VIS. A multivariate-adjusted analysis showed weight, lower STAT category, CPB time, and VIS were independent predictors for operating table and fast-track extubation.

CONCLUSIONS

Younger age, lower weight, higher RACHS-1, STAT category, and VIS, along with longer CPB and ACC, are associated with delay in the timing of tracheal extubation in pediatric cardiac surgical patients.

Factors Associated With Unplanned Post-Craniotomy Re-intubation in Children: A NSQIP-Pediatric ® Analysis

OBJECTIVE

Most children undergoing craniotomy with general endotracheal anesthesia are extubated postoperatively, but some require unplanned postoperative intubation (UPI). We sought to determine the incidence of UPI and identify associated factors and related postoperative mortality.

METHODS

The National Surgical Quality Improvement Program for Pediatrics (2012-2018) was used to retrospectively identify patients less than 18 years old who underwent craniotomy for epilepsy, tumor, and congenital/cyst procedures. Perioperative factors associated with UPI were identified with logistic regression models.

RESULTS

We identified 15,292 children, of whom 144 (0.94%) required UPI. Ninety-two (0.60%) children required UPI within the first 3 days after surgery. Postoperative mortality was higher among children with UPI within 3 days than in those with UPI later or not at all (8.0 vs. 2.2 vs. 0.3%, respectively; P <0.001). Posterior fossa procedures trended towards an increased odds of UPI (odds ratio [OR], 1.50; 95% confidence interval [CI] 0.99 to 2.27; P =0.05). Five preoperative factors were independently associated with UPI: age ≤ 12 months (OR, 2.78; 95% CI, 1.29 to 5.98), ASA classification ≥3 (OR, 1.92; 95% CI, 1.12 to 3.29), emergent case status (OR, 2.06; 95% CI, 1.30 to 3.26), neuromuscular disease (OR, 1.87; 95% CI, 1.01 to 3.47), and steroid use within 30 days (OR, 1.79; 95% CI 1.14 to 2.79). Long operative times were independently associated with UPI (200 to 400 vs. <200 min OR, 1.92; 95% CI 1.18 to 3.11 and ≥400 vs. <200 min OR, 4.66; 95% CI 2.70 to 8.03).

CONCLUSION

Although uncommon, UPI in children who underwent craniotomy was associated with an elevated risk of postoperative mortality. The presence of identifiable risk factors may be used for preoperative counseling and risk profiling in these patients.

Association of Extubation Failure Rates With High-Flow Nasal Cannula, Continuous Positive Airway Pressure, and Bilevel Positive Airway Pressure vs Conventional Oxygen Therapy in Infants and Young Children: A Systematic Review and Network Meta-Analysis

Importance

Extubation failure (EF) has been associated with worse outcomes in critically ill children. The relative efficacy of different modes of noninvasive respiratory support (NRS) to prevent EF is unknown.

Objective

To study the reported relative efficacy of different modes of NRS (high-flow nasal cannula [HFNC], continuous positive airway pressure [CPAP], and bilevel positive airway pressure [BiPAP]) compared to conventional oxygen therapy (COT).

Data Sources

MEDLINE, Embase, and CINAHL Complete through May 2022.

Study Selection

Randomized clinical trials that enrolled critically ill children receiving invasive mechanical ventilation for more than 24 hours and compared the efficacy of different modes of postextubation NRS.

Data Extraction and Synthesis

Random-effects models were fit using a bayesian network meta-analysis framework. Between-group comparisons were estimated using odds ratios (ORs) or mean differences with 95% credible intervals (CrIs). Treatment rankings were assessed by rank probabilities and the surface under the cumulative rank curve (SUCRA).

Main Outcomes and Measures

The primary outcome was EF (reintubation within 48 to 72 hours). Secondary outcomes were treatment failure (TF, reintubation plus NRS escalation or crossover to another NRS mode), pediatric intensive care unit (PICU) mortality, PICU and hospital length of stay, abdominal distension, and nasal injury.

Results

A total of 11 615 citations were screened, and 9 randomized clinical trials with a total of 1421 participants were included. Both CPAP and HFNC were found to be more effective than COT in reducing EF and TF (CPAP: OR for EF, 0.43; 95% CrI, 0.17-1.0 and OR for TF 0.27, 95% CrI 0.11-0.57 and HFNC: OR for EF, 0.64; 95% CrI, 0.24-1.0 and OR for TF, 0.34; 95% CrI, 0.16- 0.65). CPAP had the highest likelihood of being the best intervention for both EF (SUCRA, 0.83) and TF (SUCRA, 0.91). Although not statistically significant, BiPAP was likely to be better than COT for preventing both EF and TF. Compared to COT, CPAP and BiPAP were reported as showing a modest increase (approximately 3%) in nasal injury and abdominal distension.

Conclusions and Relevance

The studies included in this systematic review and network meta-analysis found that compared with COT, EF and TF rates were lower with modest increases in abdominal distension and nasal injury. Of the modes evaluated, CPAP was associated with the lowest rates of EF and TF.

Fundamental concepts and the latest evidence for esophageal pressure monitoring

Transpulmonary pressure is an essential physiologic concept as it reflects the true pressure across the alveoli, and is a more precise marker for lung stress. To calculate transpulmonary pressure, one needs an estimate of both alveolar pressure and pleural pressure. Airway pressure during conditions of no flow is the most widely accepted surrogate for alveolar pressure, while esophageal pressure remains the most widely measured surrogate marker for pleural pressure. This review will cover important concepts and clinical applications for esophageal manometry, with a particular focus on how to use the information from esophageal manometry to adjust or titrate ventilator support. The most widely used method for measuring esophageal pressure uses an esophageal balloon catheter, although these measurements can be affected by the volume of air in the balloon. Therefore, when using balloon catheters, it is important to calibrate the balloon to ensure the most appropriate volume of air, and we discuss several methods which have been proposed for balloon calibration. In addition, esophageal balloon catheters only estimate the pleural pressure over a certain area within the thoracic cavity, which has resulted in a debate regarding how to interpret these measurements. We discuss both direct and elastance-based methods to estimate transpulmonary pressure, and how they may be applied for clinical practice. Finally, we discuss a number of applications for esophageal manometry and review many of the clinical studies published to date which have used esophageal pressure. These include the use of esophageal pressure to assess lung and chest wall compliance individually which can provide individualized information for patients with acute respiratory failure in terms of setting PEEP, or limiting inspiratory pressure. In addition, esophageal pressure has been used to estimate effort of breathing which has application for ventilator weaning, detection of upper airway obstruction after extubation, and detection of patient and mechanical ventilator asynchrony.

Tests and Indices Predicting Extubation Failure in Children: A Systematic Review and Meta-analysis

INTRODUCTION

There is lack of consensus on what constitutes best practice when assessing extubation readiness in children. This systematic review aims to synthesize data from existing literature on pre-extubation assessments and evaluate their diagnostic accuracies in predicting extubation failure (EF) in children.

METHODS

A systematic search in PubMed, EMBASE, Web of Science, CINAHL, and Cochrane was performed from inception of each database to 15 July 2021. Randomized controlled trials or observational studies that studied the association between pre-extubation assessments and extubation outcome in the pediatric intensive care unit population were included. Meta-analysis was performed for studies that report diagnostic tests results of a combination of parameters.

RESULTS

In total, 41 of 11,663 publications screened were included (total patients, n = 8111). Definition of EF across studies was heterogeneous. Fifty-five unique pre-extubation assessments were identified. Parameters most studied were: respiratory rate (RR) (13/41, n = 1945), partial pressure of arterial carbon dioxide (10/41, n = 1379), tidal volume (13/41, n = 1945), rapid shallow breathing index (RBSI) (9/41, n = 1400), and spontaneous breathing trials (SBT) (13/41, n = 5652). Meta-analysis shows that RSBI, compliance rate oxygenation pressure (CROP) index, and SBT had sensitivities ranging from 0.14 to 0.57. CROP index had the highest sensitivity [0.57, 95% confidence interval (CI) 0.4-0.73] and area under curve (AUC, 0.98). SBT had the highest specificity (0.93, 95% CI 0.92-0.94).

CONCLUSIONS

Pre-extubation assessments studied thus far remain poor predictors of EF. CROP index, having the highest AUC, should be further explored as a predictor of EF. Standardizing the EF definition will allow better comparison of pre-extubation assessments.

Fitness checklist model for spontaneous breathing tests in pediatrics

OBJECTIVE

To evaluate whether a model of a daily fitness checklist for spontaneous breathing tests is able to identify predictive variables of extubation failure in pediatric patients admitted to a Brazilian intensive care unit.

METHODS

This was a single-center, cross-sectional study with prospective data collection. The checklist model comprised 20 items and was applied to assess the ability to perform spontaneous breathing tests.

RESULTS

The sample consisted of 126 pediatric patients (85 males (67.5%)) on invasive mechanical ventilation, for whom 1,217 daily assessments were applied at the bedside. The weighted total score of the prediction model showed the highest discriminatory power for the spontaneous breathing test, with sensitivity and specificity indices for fitness failure of 89.7% or success of 84.6%. The cutoff point suggested by the checklist was 8, with a probability of extubation failure less than 5%. Failure increased progressively with increasing score, with a maximum probability of predicting extubation failure of 85%.

CONCLUSION

The extubation failure rate with the use of this model was within what is acceptable in the literature. The daily checklist model for the spontaneous breathing test was able to identify predictive variables of failure in the extubation process in pediatric patients.

Monitoring in Pediatric Acute Respiratory Distress Syndrome: From the Second Pediatric Acute Lung Injury Consensus Conference

OBJECTIVES

Monitoring is essential to assess changes in the lung condition, to identify heart-lung interactions, and to personalize and improve respiratory support and adjuvant therapies in pediatric acute respiratory distress syndrome (PARDS). The objective of this article is to report the rationale of the revised recommendations/statements on monitoring from the Second Pediatric Acute Lung Injury Consensus Conference (PALICC-2).

DATA SOURCES

MEDLINE (Ovid), Embase (Elsevier), and CINAHL Complete (EBSCOhost).

STUDY SELECTION

We included studies focused on respiratory or cardiovascular monitoring of children less than 18 years old with a diagnosis of PARDS. We excluded studies focused on neonates.

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. We identified 342 studies for full-text review. Seventeen good practice statements were generated related to respiratory and cardiovascular monitoring. Four research statements were generated related to respiratory mechanics and imaging monitoring, hemodynamics monitoring, and extubation readiness monitoring.

CONCLUSIONS

PALICC-2 monitoring good practice and research statements were developed to improve the care of patients with PARDS and were based on new knowledge generated in recent years in patients with PARDS, specifically in topics of general monitoring, respiratory system mechanics, gas exchange, weaning considerations, lung imaging, and hemodynamic monitoring.

A 30-Minute Spontaneous Breathing Trial Misses Many Children Who Go On to Fail a 120-Minute Spontaneous Breathing Trial

BACKGROUND

The optimal length of spontaneous breathing trials (SBTs) in children is unknown.

RESEARCH QUESTIONS

What are the most common reasons for SBT failure in children, and when do they occur? Can clinical parameters at the 30-min mark of a 120-min SBT predict outcome?

STUDY DESIGN AND METHODS

We performed a secondary analysis of a clinical trial in pediatric ARDS, in which 2-h SBTs are conducted daily. SBT failure is based on objective criteria, including esophageal manometry for effort of breathing, categorized as passage, early failure (≤ 30 min), or late failure (30-120 min). Spirometry was used to calculate respiratory rate (RR), tidal volume (Vt), and rapid shallow breathing index (RSBI), in addition to pulse oximetry and capnography. Predictive models evaluated parameters at 30 min against SBT outcome, using receiver operating characteristic plots and area under the curve.

RESULTS

We included 100 children and 305 SBTs, with 42% of SBTs being successful, 32% failing within 30 min, and 25% failing between 30 and 120 min. Of the patients passing SBTs at 30 min, 40% went on to fail by 120 min. High respiratory effort (esophageal manometry) was present in > 80% of failed SBTs. At the 30-min mark, there were no clear thresholds for RR, Vt, RSBI, Fio2, oxygen saturation, or capnography that could reliably predict SBT outcome. Multivariable modeling identified RR (P < .001) and RSBI > 7 (P = .034) at 30 min, pre-SBT inspiratory pressure level (P = .009), and pre-SBT retractions (P = .042) as predictors for SBT failure, but this model performed poorly in an independent validation set with the receiver operating characteristic plot crossing the reference line (area under the curve, 0.67).

INTERPRETATION

A 30-min SBT may be too short in children recovering from pediatric ARDS because many go on to fail between 30 and 120 min. Reassuring values of Vt, RR, and gas exchange at 30 min do not reliably predict SBT passage at 2 h, likely because they do not capture the effort of breathing.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov; No.: NCT03266016; URL: www.

CLINICALTRIALS

gov.

Predictive factors of extubation failure in pediatric cardiac intensive care unit: A single-center retrospective study from Thailand

Introduction/objective

Extubation failure increases morbidity and mortality in pediatric cardiac patients, a unique population including those with congenital heart disease or acquired heart disease. This study aimed to evaluate the predictive factors of extubation failure in pediatric cardiac patients and to determine the association between extubation failure and clinical outcomes.

Methods

We conducted a retrospective study in the pediatric cardiac intensive care unit (PCICU) of the Faculty of Medicine, Chiang Mai University, Chiang Mai, Thailand, from July 2016 to June 2021. Extubation failure was defined as the re-insertion of the endotracheal tube within 48 hours after extubation. Multivariable log-binomial regression with generalized estimating equations (GEE) was performed to explore the predictive factors associated with extubation failure.

Results

We collected 318 extubation events from 246 patients. Of these, 35 (11%) events were extubation failures. In physiologic cyanosis, the extubation failure group had significantly higher SpO₂ than the extubation success group (P < 0.001). The predictive factors associated with extubation failure included a history of pneumonia before extubation (RR 3.09, 95% CI 1.54-6.23, P = 0.002), stridor after extubation (RR 2.57, 95% CI 1.44-4.56, P = 0.001), history of re-intubation (RR 2.24, 95% CI 1.21-4.12, P = 0.009), and palliative surgery (RR 1.87, 95% CI 1.02-3.43, P = 0.043).

Conclusion

Extubation failure was identified in 11% of extubation attempts in pediatric cardiac patients. The extubation failure was associated with a longer duration of PCICU stay but not with mortality. Patients with a history of pneumonia before extubation, history of re-intubation, post-operative palliative surgery, and post-extubation stridor should receive careful consideration before extubation and close monitoring afterward. Additionally, patients with physiologic cyanosis may require balanced circulation via regulated SpO₂.

Executive Summary: International Clinical Practice Guidelines for Pediatric Ventilator Liberation, A Pediatric Acute Lung Injury and Sepsis Investigators (PALISI) Network Document

Rationale: Pediatric-specific ventilator liberation guidelines are lacking despite the many studies exploring elements of extubation readiness testing. The lack of clinical practice guidelines has led to significant and unnecessary variation in methods used to assess pediatric patients' readiness for extubation. Methods: Twenty-six international experts comprised a multiprofessional panel to establish pediatrics-specific ventilator liberation clinical practice guidelines, focusing on acutely hospitalized children receiving invasive mechanical ventilation for more than 24 hours. Eleven key questions were identified and first prioritized using the Modified Convergence of Opinion on Recommendations and Evidence. A systematic review was conducted for questions that did not meet an a priori threshold of ⩾80% agreement, with Grading of Recommendations, Assessment, Development, and Evaluation methodologies applied to develop the guidelines. The panel evaluated the evidence and drafted and voted on the recommendations. Measurements and Main Results: Three questions related to systematic screening using an extubation readiness testing bundle and a spontaneous breathing trial as part of the bundle met Modified Convergence of Opinion on Recommendations criteria of ⩾80% agreement. For the remaining eight questions, five systematic reviews yielded 12 recommendations related to the methods and duration of spontaneous breathing trials, measures of respiratory muscle strength, assessment of risk of postextubation upper airway obstruction and its prevention, use of postextubation noninvasive respiratory support, and sedation. Most recommendations were conditional and based on low to very low certainty of evidence. Conclusions: This clinical practice guideline provides a conceptual framework with evidence-based recommendations for best practices related to pediatric ventilator liberation.

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.

Operational Definitions Related to Pediatric Ventilator Liberation

BACKGROUND

Common, operational definitions are crucial to assess interventions and outcomes related to pediatric mechanical ventilation. These definitions can reduce unnecessary variability among research and quality improvement efforts, to ensure findings are generalizable, and can be pooled to establish best practices.

RESEARCH QUESTION

Can we establish operational definitions for key elements related to pediatric ventilator liberation using a combination of detailed literature review and consensus-based approaches?

STUDY DESIGN AND METHODS

A panel of 26 international experts in pediatric ventilator liberation, two methodologists, and two librarians conducted systematic reviews on eight topic areas related to pediatric ventilator liberation. Through a series of virtual meetings, we established draft definitions that were voted upon using an anonymous web-based process. Definitions were revised by incorporating extracted data gathered during the systematic review and discussed in another consensus meeting. A second round of voting was conducted to confirm the final definitions.

RESULTS

In eight topic areas identified by the experts, 16 preliminary definitions were established. Based on initial discussion and the first round of voting, modifications were suggested for 11 of the 16 definitions. There was significant variability in how these items were defined in the literature reviewed. The final round of voting achieved ≥ 80% agreement for all 16 definitions in the following areas: what constitutes respiratory support (invasive mechanical ventilation and noninvasive respiratory support), liberation and failed attempts to liberate from invasive mechanical ventilation, liberation from respiratory support, duration of noninvasive respiratory support, total duration of invasive mechanical ventilation, spontaneous breathing trials, extubation readiness testing, 28 ventilator-free days, and planned vs rescue use of post-extubation noninvasive respiratory support.

INTERPRETATION

We propose that these consensus-based definitions for elements of pediatric ventilator liberation, informed by evidence, be used for future quality improvement initiatives and research studies to improve generalizability and facilitate comparison.

Diaphragmatic Thickening Fraction by Ultrasound in Mechanically Ventilated Pediatric Patients: Pilot Observations During Spontaneous Breathing Trials

OBJECTIVES

In critically ill, mechanically ventilated adults, diaphragmatic atrophy and reduced diaphragmatic thickening fraction (DTF) has been associated with poor extubation outcomes. Diaphragmatic ultrasound assessment in critically ill pediatric patients shows similar results, though studies are on-going. We sought to explore the feasibility and utility of using DTF, obtained during a spontaneous breathing trial (SBT) in predicting weaning outcomes.

METHODS

We conducted a prospective, observational study in a single-center tertiary noncardiac pediatric intensive care unit (PICU) in a children's hospital. Mechanically ventilated pediatric patients were included except for those with preexisting conditions of neuromuscular weakness, diaphragm paresis, or chronic respiratory failure requiring non-invasive or invasive mechanical ventilation at baseline. A convenience sample of 38 patients were included in the study.

RESULTS

Weaning failure occurred in 10/38 (26%) instances with 9/38 (24%) occurring due to failed SBT and 1/38 (2%) due to failed extubation requiring reintubation. Median DTF was 24% (IQR: 12-33). DTF was significantly lower in instances of failed SBT, 12% compared to 27% (P < .01). The odds ratio (OR) of SBT failure utilizing: TF < 25% is 12 (CI: 1.33-108.0, Z-score: 2.22, P = .027), TV <5 mL/kg was 10.4 (CI: 1.76-61.67, Z-score: 2.58, P = .01), and combined TV <5 mL/kg and TF < 25% is 17.6 (CI: 1.19-259.61, Z-score: 2.09, P = .04).

CONCLUSIONS

Our preliminary study suggests that ultrasound measurements of diaphragm thickening fraction during spontaneous breaths in mechanically ventilated pediatric patients may be a useful addition in predicting weaning readiness.

Clinical Challenges in Pediatric Ventilation Liberation: A Meta-Narrative Review

OBJECTIVES

To map the evidence for ventilation liberation practices in pediatric respiratory failure using the Realist And MEta-narrative Evidence Syntheses: Evolving Standards publication standards.

DATA SOURCES

CINAHL, MEDLINE, COCHRANE, and EMBASE. Trial registers included the following: ClinicalTrials.gov, European Union clinical trials register, International Standardized Randomized Controlled Trial Number register.

STUDY SELECTION

Abstracts were screened followed by review of full text. Articles published in English language incorporating a heterogeneous population of both infants and older children were assessed.

DATA EXTRACTION

None.

DATA SYNTHESIS

Weaning can be considered as the process by which positive pressure is decreased and the patient becomes increasingly responsible for generating the energy necessary for effective gas exchange. With the growing use of noninvasive respiratory support, extubation can lie in the middle of the weaning process if some additional positive pressure is used after extubation, while for some extubation may constitute the end of weaning. Testing for extubation readiness is a key component of the weaning process as it allows the critical care practitioner to assess the capability and endurance of the patient's respiratory system to resume unassisted ventilation. Spontaneous breathing trials (SBTs) are often seen as extubation readiness testing (ERT), but the SBT is used to determine if the patient can maintain adequate spontaneous ventilation with minimal ventilatory support, whereas ERT implies the patient is ready for extubation.

CONCLUSIONS

Current literature suggests using a structured approach that includes a daily assessment of patient's readiness to extubate may reduce total ventilation time. Increasing evidence indicates that such daily assessments needs to include SBTs without added pressure support. Measures of elevated load as well as measures of impaired respiratory muscle capacity are independently associated with extubation failure in children, indicating that these should also be assessed as part of ERT.

Individualized Analysis and Treatment of Difficult Weaning From Ventilation Following Open Cardiac Surgery in Young Children With Congenital Heart Disease

Aims

The study explores the leading causes of postoperative extubation difficulties in pediatric patients (neonates and toddlers) with congenital heart diseases and establishes individualized treatment for different reasons.

Method

We retrospectively analyzed medical records of 4,971 pediatric patients with congenital heart defects treated in three tertiary Congenital Heart Disease Centres in China from January 2005 to December 2020, from whom we selected those with difficulty extubation but successful weaning during the postoperative period. Next, we performed an analysis of risk factors and reported the combined experience of individualized treatment for successful extubation.

Results

Seventy-five pediatric patients were identified in our database, among whom 23 had airway stenosis, 17 had diaphragmatic dysfunction, and 35 had pulmonary infection. The patients were all successfully weaned from the ventilator after an individualized treatment plan. In addition, the intubation time in the airway stenosis group was 17.7 ± 9.0, 33.6 ± 13.9 days in the diaphragmatic dysfunction group, and 11.9 ± 3.8 days in the pulmonary infection group.

Conclusion

Given the primary reasons for difficult weaning following open-heart surgery in pediatric patients with congenital heart diseases, an individualized treatment scheme can achieve the ideal therapeutic effect where patients can be weaned faster with a shorter intubation period.

Diaphragm Ultrasonography to Predict Noninvasive Respiratory Treatment Failure in Infants With Severe Bronchiolitis

BACKGROUND

Noninvasive respiratory support is commonly used in treatment of bronchiolitis. Determinants of failure are needed to prevent delayed intubation.

METHODS

We conducted a prospective observational pilot study in infants admitted to a pediatric ICU. Diaphragmatic excursion (dExc), diaphragmatic inspiratory/expiratory time, and diaphragmatic thickening fraction (dTF) were recorded at admission, 24 h, and 48 h in both hemidiaphragms.

RESULTS

Twenty-six subjects were included (14 on HFNC and 12 on NIV) with a total of 56 ultrasonographic evaluations. Three subjects required invasive ventilation. Sixty-four percent of the subjects on HFNC required NIV as rescue therapy and 2/14 invasive ventilation (14.2%). In the HFNC group there were no differences in dExc between those who required escalation to NIV or invasive ventilation and those who didn't. Left dTF was higher in subjects on HFNC requiring invasive ventilation versus those needing NIV (left dTF 47% vs 22% [13-30]; P = .046, r = 0.7). Diaphragmatic I:E ratios were higher in infants on HFNC requiring invasive ventilation and diaphragmatic expiratory time was shorter (left P = .038; right P = .02). In the NIV group there were no differences in dExc, I:E ratios, or dTF between subjects needing escalation to invasive ventilation and those who didn't. We found no correlation between a clinical work of breathing score and echographic dTF.

CONCLUSIONS

In infants with moderate or severe bronchiolitis receiving HFNC, the use of ultrasonographic left dTF could help predict respiratory treatment failure and need for invasive ventilation. The use of ultrasonographic dExc is of little help to predict both.

The Decision to Extubate: The Association Between Clinician Impressions and Objective Extubation Readiness Criteria in a Pediatric Intensive Care Unit

Objective Objective tools such as spontaneous breathing trials (SBT) aim to identify patients ready for extubation and shorten the length of mechanical ventilation (MV). Despite passing an SBT, patients sometimes are not extubated based on clinicians' subjective impressions. In this article, we explored the factors that influence the decision to extubate among pediatric intensivists and their association with objective criteria.

Design This is a single-center prospective observational study.

Setting This study was conducted in an academic, multidisciplinary 20-bed pediatric intensive care unit (PICU).

Patients The study group involves mechanically ventilated, orally intubated patients admitted to the PICU from January 1 to June 30, 2019.

Measurements and Main Results Objective clinical data were collected for 650 MV days. Attending surveys about extubation readiness were completed for 419 (64.5%) MV days and 63 extubation events. Extubation occurred on 42% of days after passing an SBT. The primary reasons patients who passed an SBT were not extubated on days were unresolved lung pathology (66.6%) and fluid overload (37.6%). On days without extubation, there was no association between a specific reason for not extubating and SBT result (p > 0.05).

Conclusions In this single-center study, the decision to extubate was not strongly associated with passing an SBT, indicating that clinician impressions, namely unresolved lung pathology and fluid overload, outweighed objective measures for determining extubation readiness. To mitigate morbidities and costs associated with unnecessarily prolonged intubations, a better-defined extubation readiness process is needed to guide the decision to extubate in the pediatric population.

Ventilation Weaning and Extubation Readiness in Children in Pediatric Intensive Care Unit: A Review

Ventilation is one of the most common procedures in critically ill children admitted to the pediatric intensive care units (PICUs) and is associated with potential severe side effects. The longer the mechanical ventilation, the higher the risk of infections, mortality, morbidity and length of stay. Protocol-based approaches to ventilation weaning could have potential benefit in assisting the physicians in the weaning process but, in pediatrics, clear significant outcome difference related to their use has yet to be shown. Extubation failure occurs in up to 20% of patients in PICU with evidences demonstrating its occurrence related to a worse patient outcome including higher mortality. Various clinical approaches have been described to decide the best timing for extubation which can usually be achieved by performing a spontaneous breathing trial before the extubation. No clear evidence is available over which technique best predicts extubation failure. Within this review we summarize the current strategies of ventilation weaning and extubation readiness evaluation employed in the pediatric setting in order to provide an updated view on the topic to guide intensive care physicians in daily clinical practice. We performed a thorough literature search of main online scientific databases to identify principal studies evaluating different strategies of ventilation weaning and extubation readiness including pediatric patients receiving mechanical ventilation. Various strategies are available in the literature both for ventilation weaning and extubation readiness assessment with unclear clear data supporting the superiority of any approach over the others.

The Effects of Manual Lung Hyperinflation on Pulmonary Function after Weaning from Mechanical Ventilation among Patients with Abdominal Surgeries: Randomized Clinical Trial

Introduction: After abdominal surgery, the patients who are separated from mechanical ventilation and provided with oxygen therapy via a T-piece are at risk for respiratory complications. Therefore, they need additional respiratory support. This study aimed to evaluate the effects of manual hyperinflation (MHI) on pulmonary function after weaning. Methods: This randomized clinical trial included 40 patients who had undergone abdominal surgery and were receiving oxygen via a T-piece. Patients were selected from the intensive care units (ICU) of two hospitals in Mashhad, Iran. The subjects were randomly allocated to intervention (MHI) and control groups. Patients in the MHI group were provided with three 20-minute MHI rounds using the Mapleson C, while the control group received routine cares. Tidal volume (Vt), Rapid Shallow Breathing Index (RSBI), and the ratio of arterial oxygen partial pressure to fractional inspired oxygen (P/F ratio) were measured before the intervention, as well as 5 and 20 minutes after the intervention. Atelectasis prevalence was assessed before and 24 hours after the intervention. Data were analysed by SPSS software version 13. Results: At baseline, there were no significant differences between the groups regarding Vt, RSBI, P/F ratio, and atelectasis rate. No significant difference was also found between the groups regarding atelectasis rate 24 hours after the intervention. However, at both posttests, Vt, RSBI, and P/F ratio in the MHI group were significantly better than the control group. Conclusion: In patients with artificial airway and spontaneous breathing, MHI improves pulmonary function.

Diaphragm Activity Pre and Post Extubation in Ventilated Critically Ill Infants and Children Measured With Transcutaneous Electromyography

OBJECTIVES

Swift extubation is important to prevent detrimental effects of invasive mechanical ventilation but carries the risk of extubation failure. Accurate tools to assess extubation readiness are lacking. This study aimed to describe the effect of extubation on diaphragm activity in ventilated infants and children. Our secondary aim was to compare diaphragm activity between failed and successfully extubated patients.

DESIGN

Prospective, observational study.

SETTING

Single-center tertiary neonatal ICU and PICU.

PATIENTS

Infants and children receiving invasive mechanical ventilation longer than 24 hours.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Diaphragm activity was measured with transcutaneous electromyography, from 15 minutes before extubation till 180 minutes thereafter. Peak and tonic activity, inspiratory amplitude, inspiratory area under the curve, and respiratory rate were calculated from the diaphragm activity waveform. One hundred forty-seven infants and children were included (median postnatal age, 1.9; interquartile range, 0.9-6.7 wk). Twenty patients (13.6%) failed extubation within 72 hours. Diaphragm activity increased rapidly after extubation and remained higher throughout the measurement period. Pre extubation, peak (end-inspiratory) diaphragm activity and tonic (end-inspiratory) diaphragm activity were significantly higher in failure, compared with success cases (5.6 vs 7.0 μV; p = 0.04 and 2.8 vs 4.1 μV; p = 0.04, respectively). Receiver operator curve analysis showed the highest area under the curve for tonic (end-inspiratory) diaphragm activity (0.65), with a tonic (end-inspiratory) diaphragm activity greater than 3.4 μV having a combined sensitivity and specificity of 55% and 77%, respectively, to predict extubation outcome. After extubation, diaphragm activity remained higher in patients failing extubation.

CONCLUSIONS

Diaphragm activity rapidly increased after extubation. Patients failing extubation had a higher level of diaphragm activity, both pre and post extubation. The predictive value of the diaphragm activity variables alone was limited. Future studies are warranted to assess the additional value of electromyography of the diaphragm in combined extubation readiness assessment.

Predictive power of extubation failure diagnosed by cough strength: a systematic review and meta-analysis

Background

The predictive power of extubation failure diagnosed by cough strength varies by study. Here we summarise the diagnostic power of extubation failure tested by cough strength.

Methods

A comprehensive online search was performed to select potentially eligible studies that evaluated the predictive power of extubation failure tested by cough strength. A manual search was also performed to identify additional studies. Data were extracted to calculate the pooled sensitivity, specificity, positive likelihood ratio (LR), negative LR, diagnostic odds ratio (DOR), and area under the receiver operating characteristic curve (AUC) to evaluate the predictive power of extubation failure.

Results

A total of 34 studies involving 45 study arms were enrolled, and 7329 patients involving 8684 tests were analysed. In all, 23 study arms involving 3018 tests measured cough peak flow before extubation. The pooled extubation failure was 36.2% and 6.3% in patients with weak and strong cough assessed by cough peak flow, respectively. The pooled sensitivity, specificity, positive LR, negative LR, DOR, and AUC were 0.76 (95% confidence interval [CI]: 0.72–0.80), 0.75 (0.69–0.81), 2.89 (2.36–3.54), 0.37 (0.30–0.45), 8.91 (5.96–13.32), and 0.79 (0.75–0.82), respectively. Moreover, 22 study arms involving 5666 tests measured the semiquantitative cough strength score (SCSS) before extubation. The pooled extubation failure was 37.1% and 11.3%, respectively, in patients with weak and strong cough assessed by the SCSS. The pooled sensitivity, specificity, positive LR, negative LR, DOR, and AUC were 0.53 (95% CI: 0.41–0.64), 0.83 (0.74–0.89), 2.50 (1.93–3.25), 0.65 (0.56–0.76), 4.61 (3.03–7.01), and 0.74 (0.70–0.78), respectively.

Conclusions

Weak cough is associated with increased extubation failure. Cough peak flow is superior to the SCSS for predicting extubation failure. However, both show moderate power for predicting extubation failure.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03781-5.

Evolution of inspiratory muscle function in children during mechanical ventilation

BACKGROUND

There is no universally accepted method to assess the pressure-generating capacity of inspiratory muscles in children on mechanical ventilation (MV), and no study describing its evolution over time in this population.

METHODS

In this prospective observational study, we have assessed the function of the inspiratory muscles in children on various modes of MV. During brief airway occlusion maneuvers, we simultaneously recorded airway pressure depression at the endotracheal tube (ΔPaw, force generation) and electrical activity of the diaphragm (EAdi, central respiratory drive) over five consecutive inspiratory efforts. The neuro-mechanical efficiency ratio (NME, ΔPaw/EAdimax) was also computed. The evolution over time of these indices in a group of children in the pediatric intensive care unit (PICU) was primarily described. As a secondary objective, we compared these values to those measured in a group of children in the operating room (OR).

RESULTS

In the PICU group, although median NMEoccl decreased over time during MV (regression coefficient - 0.016, p = 0.03), maximum ΔPawmax remained unchanged (regression coefficient 0.109, p = 0.50). Median NMEoccl at the first measurement in the PICU group (after 21 h of MV) was significantly lower than at the only measurement in the OR group (1.8 cmH2O/µV, Q1-Q3 1.3-2.4 vs. 3.7 cmH2O/µV, Q1-Q3 3.5-4.2; p = 0.015). Maximum ΔPawmax in the PICU group was, however, not significantly different from the OR group (35.1 cmH2O, Q1-Q3 21-58 vs. 31.3 cmH2O, Q1-Q3 28.5-35.5; p = 0.982).

CONCLUSIONS

The function of inspiratory muscles can be monitored at the bedside of children on MV using brief airway occlusions. Inspiratory muscle efficiency was significantly lower in critically ill children than in children undergoing elective surgery, and it decreased over time during MV in critically ill children. This suggests that both critical illness and MV may have an impact on inspiratory muscle efficiency.

Prevalence of Reintubation Within 24 Hours of Extubation in Bronchiolitis: Retrospective Cohort Study Using the Virtual Pediatric Systems Database

OBJECTIVES

High-flow nasal cannula and noninvasive positive pressure ventilation are used to support children following liberation from invasive mechanical ventilation. Evidence comparing extubation failure rates between patients randomized to high-flow nasal cannula and noninvasive positive pressure ventilation is available for adult and neonatal patients; however, similar pediatric trials are lacking. In this study, we employed a quality controlled, multicenter PICU database to test the hypothesis that high-flow nasal cannula is associated with higher prevalence of reintubation within 24 hours among patients with bronchiolitis.

DESIGN

Secondary analysis of a prior study utilizing the Virtual Pediatric Systems database.

SETTING

One-hundred twenty-four participating PICUs.

PATIENTS

Children less than 24 months old with a primary diagnosis of bronchiolitis who were admitted to one of 124 PICUs between January 2009 and September 2015 and received invasive mechanical ventilation.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Among 759 patients, median age was 2.4 months (1.3-5.4 mo), 41.2% were female, 39.7% had greater than or equal to 1 comorbid condition, and 43.7% were Caucasian. Median PICU length of stay was 8.7 days (interquartile range, 5.8-13.7 d) and survival to PICU discharge was 100%. Median duration of intubation was 5.5 days (3.4-9.0 d) prior to initial extubation. High-flow nasal cannula was used following extubation in most (656 [86.5%]) analyzed subjects. The overall prevalence of reintubation within 24 hours was 5.9% (45 children). Extubation to noninvasive positive pressure ventilation was associated with greater prevalence of reintubation than extubation to high-flow nasal cannula (11.7% vs 5.0%; p = 0.016) and, in an a posteriori model that included Pediatric Index of Mortality 2 score and comorbidities, was associated with increased odds of reintubation (odds ratio, 2.43; 1.11-5.34; p = 0.027).

CONCLUSIONS

In this secondary analysis of a multicenter database of children with bronchiolitis, extubation to high-flow nasal cannula was associated with a lower prevalence of reintubation within 24 hours compared with noninvasive positive pressure ventilation in both unmatched and propensity-matched analysis. Prospective trials are needed to determine if post-extubation support modality can mitigate the risk of extubation failure.

Extubation Readiness Practices and Barriers to Extubation in Pediatric Subjects

BACKGROUND

Invasive mechanical ventilation is a lifesaving intervention that is associated with short- and long-term morbidities. Extubation readiness protocols aim to decrease extubation failure rates and simultaneously shorten the duration of invasive ventilation. This study sought to analyze extubation readiness practices at one institution and identify barriers to extubation in pediatric patients who have passed an extubation readiness test (ERT).

METHODS

We performed a retrospective chart review of all pediatric subjects admitted between April 2017 and March 2018, and who were on mechanical ventilation. Exclusion criteria were cardiac ICU admission, tracheostomy, chronic ventilator support, limited resuscitation status, and death before extubation attempt. Data with regard to the method of ERT and reasons for delaying extubation were collected.

RESULTS

There were 427 subjects included in the analysis with 69% having had an ERT before extubation. Of those, 39% were extubated per our daily spontaneous breathing trial (SBT) protocol, and the daily SBT failed in 30% but they had passed a subsequent pressure support and CPAP trial on the same day. The most common reasons for failing the daily SBT were a lack of spontaneous breathing (30% [75/252]), being intubated < 24 h (24% [60/252]), breathing frequency outside the target range (22% [55/252]), and not meeting tidal volume goal (14% [34/252]). The most common documented reasons for delaying extubation despite passing daily SBT were planned procedure (29% [26/90]), neurologic status (23% [21/90]), and no leak around the endotracheal tube (18% [16/90]). The median time between passing ERT and extubation was 7 h (interquartile range, 5-10).

CONCLUSIONS

In our institution, there was variation in extubation readiness practices that could lead to a significant delay in liberation from invasive ventilation. Adjustment of our daily SBT to tolerate a higher work of breathing, such as higher breathing frequencies and lower tidal volumes, and incorporating sedation scoring into the protocol could be made without significantly affecting extubation failure rates.

Ventilator Liberation in the Pediatric ICU

Despite the accepted importance of minimizing time on mechanical ventilation, only limited guidance on weaning and extubation is available from the pediatric literature. A significant proportion of patients being evaluated for weaning are actually ready for extubation, suggesting that weaning is often not considered early enough in the course of ventilation. Indications for extubation are often not clear, although a trial of spontaneous breathing on CPAP without pressure support seems an appropriate prerequisite in many cases. Several indexes have been developed to predict weaning and extubation success, but the available literature suggests they offer little or no improvement over clinical judgment. New techniques for assessing readiness for weaning and predicting extubation success are being developed but are far from general acceptance in pediatric practice. While there have been some excellent physiologic, observational, and even randomized controlled trials on aspects of pediatric ventilator liberation, robust research data are lacking. Given the lack of data in many areas, a determined approach that combines systematic review with consensus opinion of international experts could generate high-quality recommendations and terminology definitions to guide clinical practice and highlight important areas for future research in weaning, extubation readiness, and liberation from mechanical ventilation following pediatric respiratory failure.

Extubation in the pediatric intensive care unit: predictive methods. An integrative literature review

For extubation in pediatric patients, the evaluation of readiness is strongly recommended. However, a device or practice that is superior to clinical judgment has not yet been accurately determined. Thus, it is important to conduct a review on the techniques of choice in clinical practice to predict extubation failure in pediatric patients. Based on a search in the PubMed®, Biblioteca Virtual em Saúde, Cochrane Library and Scopus databases, we conducted a survey of the predictive variables of extubation failure most commonly used in clinical practice in pediatric patients. Of the eight predictors described, the three most commonly used were the spontaneous breathing test, the rapid shallow breathing index and maximum inspiratory pressure. Although the disparity of the data presented in the studies prevented statistical treatment, it was still possible to describe and analyze the performance of these tests.

Recurrent Extubation Failure Following Neonatal Cardiac Surgery Is Associated with Increased Mortality

Extubation failure (EF) following neonatal cardiac surgery is associated with increased mortality. Neonates who experienced EF twice or more (recurrent EF) may have worse outcomes than those who have a single EF or no-EF. The aims of this study are to investigate the in hospital mortality for neonates with recurrent EF compared to those with single or no-EF, and determine factors associated with recurrent EF. Neonates' ≤ 28 days who underwent cardiac surgery from January 2008 to December 2019 were included. EF was defined as unplanned reintubation within 72 h after a planned extubation. 1187 (18 recurrent EF, 84 single EF and 1085 no-EF) neonates were included. Recurrent EF occurred in 18 (17.6%) of 102 neonates undergoing a second extubation. The median time (IQR) to reintubation after the first and second extubations were similar, being 20.9 (3.3-45.2) versus 19.4 (5.5-47) h. The reason for a second-time EF was respiratory in 39% and cardiovascular in 33%. Recurrent EF and single EF was associated with increased mortality (odds ratio, 95% confidence interval (CI) 23.5, 6.9-79.9) and (odds ratio, 95% CI 5.2, 2.3-12.0) compared to no-EF. Based on the final model with risk adjustment, predicted mortality was 29.0% in recurrent EF, 6.5% in single EF, and 1.2% in no-EF. First-time EF due to cardiovascular compromise was associated with recurrent EF (odds ratio, 95% CI 3.1, 1.0-9.7). This study confirmed that patients with recurrent EF have a high morality. Neonates with a cardiovascular reason for first-time EF are more likely to have a recurrent EF than those with other causes.

Progression of Respiratory Support Following Pediatric Extubation

OBJECTIVES

High-flow nasal cannula and noninvasive positive pressure ventilation have become ubiquitous in contemporary PICUs. Practice patterns associated with the use of these modalities have not been well described. In this study, we aimed to describe the use of high-flow nasal cannula and noninvasive positive pressure ventilation in children after extubation and analyze the progression of usage in association with patient factors. Our secondary aim was to describe interventions used for postextubation stridor.

DESIGN

Single-center retrospective cohort study.

SETTING

A 36-bed quaternary medical-surgical PICU.

PATIENTS

Mechanically ventilated pediatric patients admitted between April 2017 and March 2018. Exclusions were patients in the cardiac ICU, patients requiring a tracheostomy or chronic ventilatory support, and patients with limited resuscitation status.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Data regarding respiratory modality use was collected for the first 72 hours after extubation. There were 427 patients included in the analysis; 51 patients (11.9%) were extubated to room air, 221 (51.8%) to nasal cannula, 132 (30.9%) to high-flow nasal cannula, and 23 (5.4%) to noninvasive positive pressure ventilation. By 72 hours, 314 patients (73.5%) were on room air, 52 (12.2%) on nasal cannula, 29 (6.8%) on high-flow nasal cannula, eight (1.9%) on noninvasive positive pressure ventilation, and 24 (5.6%) were reintubated. High-flow nasal cannula was the most used respiratory modality for postextubation stridor. Multivariate analysis demonstrated that longer duration of invasive mechanical ventilation increased the odds of initial high-flow nasal cannula and noninvasive positive pressure ventilation use, and a diagnosis of cerebral palsy increased the odds of escalating from high-flow nasal cannula to noninvasive positive pressure ventilation in the first 24 hours post extubation.

CONCLUSIONS

High-flow nasal cannula is commonly used immediately after pediatric extubation and the development of postextubation stridor; however, its usage sharply declines over the following 72 hours. Larger multicenter trials are needed to identify high-risk patients for extubation failure that might benefit the most from prophylactic use of high-flow nasal cannula and noninvasive positive pressure ventilation after extubation.

Lung- and Diaphragm-Protective Ventilation

Mechanical ventilation can cause acute diaphragm atrophy and injury, and this is associated with poor clinical outcomes. Although the importance and impact of lung-protective ventilation is widely appreciated and well established, the concept of diaphragm-protective ventilation has recently emerged as a potential complementary therapeutic strategy. This Perspective, developed from discussions at a meeting of international experts convened by PLUG (the Pleural Pressure Working Group) of the European Society of Intensive Care Medicine, outlines a conceptual framework for an integrated lung- and diaphragm-protective approach to mechanical ventilation on the basis of growing evidence about mechanisms of injury. We propose targets for diaphragm protection based on respiratory effort and patient-ventilator synchrony. The potential for conflict between diaphragm protection and lung protection under certain conditions is discussed; we emphasize that when conflicts arise, lung protection must be prioritized over diaphragm protection. Monitoring respiratory effort is essential to concomitantly protect both the diaphragm and the lung during mechanical ventilation. To implement lung- and diaphragm-protective ventilation, new approaches to monitoring, to setting the ventilator, and to titrating sedation will be required. Adjunctive interventions, including extracorporeal life support techniques, phrenic nerve stimulation, and clinical decision-support systems, may also play an important role in selected patients in the future. Evaluating the clinical impact of this new paradigm will be challenging, owing to the complexity of the intervention. The concept of lung- and diaphragm-protective ventilation presents a new opportunity to potentially improve clinical outcomes for critically ill patients.

Additional work of breathing from trigger errors in mechanically ventilated children

Background

Patient–ventilator asynchrony is associated with increased morbidity and mortality. A direct causative relationship between Patient–ventilator asynchrony and adverse clinical outcome have yet to be demonstrated. It is hypothesized that during trigger errors excessive pleural pressure swings are generated, contributing to increased work-of-breathing and self-inflicted lung injury. The objective of this study was to determine the additional work-of-breathing and pleural pressure swings caused by trigger errors in mechanically ventilated children.

Methods

Prospective observational study in a tertiary paediatric intensive care unit in an university hospital. Patients ventilated > 24 h and < 18 years old were studied. Patients underwent a 5-min recording of the ventilator flow–time, pressure–time and oesophageal pressure–time scalar. Pressure–time–product calculations were made as a proxy for work-of-breathing. Oesophageal pressure swings, as a surrogate for pleural pressure swings, during trigger errors were determined.

Results

Nine-hundred-and-fifty-nine trigger errors in 28 patients were identified. The additional work-of-breathing caused by trigger errors showed great variability among patients. The more asynchronous breaths were present the higher the work-of-breathing of these breaths. A higher spontaneous breath rate led to a lower amount of trigger errors. Patient–ventilator asynchrony was not associated with prolonged duration of mechanical ventilation or paediatric intensive care stay.

Conclusions

The additional work-of-breathing caused by trigger errors in ventilated children can take up to 30–40% of the total work-of-breathing. Trigger errors were less common in patients breathing spontaneously and those able to generate higher pressure–time–product and pressure swings.

Trial registration

Not applicable.

Real-Time Effort Driven Ventilator Management: A Pilot Study

OBJECTIVES

Mechanical ventilation of patients with acute respiratory distress syndrome should balance lung and diaphragm protective principles, which may be difficult to achieve in routine clinical practice. Through a Phase I clinical trial, we sought to determine whether a computerized decision support-based protocol (real-time effort-driven ventilator management) is feasible to implement, results in improved acceptance for lung and diaphragm protective ventilation, and improves clinical outcomes over historical controls.

DESIGN

Interventional nonblinded pilot study.

SETTING

PICU.

PATIENTS

Mechanically ventilated children with acute respiratory distress syndrome.

INTERVENTIONS

A computerized decision support tool was tested which prioritized lung-protective management of peak inspiratory pressure-positive end-expiratory pressure, positive end-expiratory pressure/FIO2, and ventilatory rate. Esophageal manometry was used to maintain patient effort in a physiologic range. Protocol acceptance was reported, and enrolled patients were matched 4:1 with respect to age, initial oxygenation index, and percentage of immune compromise to historical control patients for outcome analysis.

MEASUREMENTS AND MAIN RESULTS

Thirty-two patients were included. Acceptance of protocol recommendations was over 75%. One-hundred twenty-eight matched historical controls were used for analysis. Compared with historical controls, patients treated with real-time effort-driven ventilator management received lower peak inspiratory pressure-positive end-expiratory pressure and tidal volume, and higher positive end-expiratory pressure when FIO2 was greater than 0.60. Real-time effort-driven ventilator management was associated with 6 more ventilator-free days, shorter duration until the first spontaneous breathing trial and 3 fewer days on mechanical ventilation among survivors (all p ≤ 0.05) in comparison with historical controls, while maintaining no difference in the rate of reintubation.

CONCLUSIONS

A computerized decision support-based protocol prioritizing lung-protective ventilation balanced with reduction of controlled ventilation to maintain physiologic levels of patient effort can be implemented and may be associated with shorter duration of ventilation.

Influence of Early Extubation Location on Outcomes Following Pediatric Cardiac Surgery

OBJECTIVES

Early extubation following pediatric cardiac surgery is common, but debate exists whether location affects outcome, with some centers performing routine early extubations in the operating room (odds ratio) and others in the cardiac ICU. We aimed to define early extubation practice variation across hospitals and assess impact of location on hospital length-of-stay and other outcomes.

DESIGN

Secondary analysis of the Pediatric Cardiac Critical Care Consortium registry.

SETTING

Twenty-eight Pediatric Cardiac Critical Care Consortium hospitals.

PATIENTS

Patients undergoing Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery mortality category 1-3 operations between August 2014 and February 2018.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We defined early extubation as extubation less than 6 hours after postoperative admission. Hospitals were categorized based on the proportion of their early extubation patients who underwent an odds ratio extubation. Categories included low- (< 50% of early extubation, n = 12), medium- (50%-90%, n = 8), or high- (> 90%, n = 8) frequency odds ratio early extubation centers. The primary outcome of interest was postoperative hospital length-of-stay. We analyzed 16,594 operations (9,143 early extubation, 55%). Rates of early extubation ranged from 16% to 100% across hospitals. Odds ratio early extubation rates varied from 16% to 99%. Patient characteristics were similar across hospital odds ratio early extubation categories. Early extubation rates paralleled the hospital odds ratio early extubation rates-77% patients underwent early extubation at high-frequency odds ratio extubation centers compared with 39% at low-frequency odds ratio extubation centers (p < 0.001). High- and low-frequency odds ratio early extubation hospitals had similar length-of-stay, cardiac arrest rates, and low mortality. However, high-frequency odds ratio early extubation hospitals used more noninvasive ventilation than low-frequency hospitals (15% vs. 9%; p < 0.01), but had fewer extubation failures (3.6% vs. 4.5%; p = 0.02).

CONCLUSIONS

Considerable variability exists in early extubation practices after low- and moderate-complexity pediatric cardiac surgery. In this patient population, hospital length-of-stay did not differ significantly between centers with different early extubation strategies based on location or frequency.

A prospective observational study on critically ill children with diaphragmatic dysfunction: clinical outcomes and risk factors

Background

Diaphragmatic dysfunction (DD) has a great negative impact on clinical outcomes, and it is a well-recognized complication in adult patients with critical illness. However, DD is largely unexplored in the critically ill pediatric population. The aim of this study was to identify risk factors associated with DD, and to investigate the effects of DD on clinical outcomes among critically ill children.

Methods

Diaphragmatic function was assessed by diaphragm ultrasound. According to the result of diaphragmatic ultrasound, all enrolled subjects were categorized into the DD group (n = 24) and the non-DD group (n = 46). Collection of sample characteristics in both groups include age, sex, height, weight, primary diagnosis, complications, laboratory findings, medications, ventilatory time and clinical outcomes.

Results

The incidence of DD in this PICU was 34.3%. The level of CRP at discharge (P = 0.003) in the DD group was higher than the non-DD group, and duration of elevated C-reactive protein (CRP) (P < 0.001), sedative days (P = 0.008) and ventilatory treatment time (P < 0.001) in the DD group was significantly longer than the non-DD group. Ventilatory treatment time and duration of elevated CRP were independently risk factors associated with DD. Patients in the DD group had longer PICU length of stay, higher rate of weaning or extubation failure and higher mortality.

Conclusion

DD is associated with poorer clinical outcomes in critically ill childern, which include a longer PICU length of stay, higher rate of weaning or extubation failure and a higher mortality. The ventilatory treatment time and duration of elevated CRP are main risk factors of DD in critically ill children.

Trial registration

Current Controlled Trials ChiCTR1800020196, Registered 01 Dec 2018.

Diaphragm Atrophy During Pediatric Acute Respiratory Failure Is Associated With Prolonged Noninvasive Ventilation Requirement Following Extubation

OBJECTIVES

Diaphragm atrophy is evident during invasive ventilation for pediatric acute respiratory failure, but with unknown significance. We hypothesized that diaphragm atrophy in pediatric acute respiratory failure is associated with prolonged noninvasive positive pressure ventilation following extubation.

DESIGN

Prospective observational study.

SETTING

Single-center academic PICU.

PATIENTS

Invasively ventilated children with acute respiratory failure.

INTERVENTIONS

Diaphragm ultrasound was performed within 36 hours after intubation and repeated within 48 hours preceding extubation. Rapid shallow breathing index at 15 and 30 minutes of a spontaneous breathing trial and negative inspiratory force were collected in a subset of patients concurrently with the ultrasound measurements.

MEASUREMENTS AND MAIN RESULTS

Diaphragm thickness at end-expiration was measured to assess for diaphragm atrophy during mechanical ventilation. Percentage change in diaphragm thickness at end-expiration was defined as baseline diaphragm thickness at end-expiration minus final, preextubation diaphragm thickness at end-expiration divided by baseline diaphragm thickness at end-expiration. The primary outcome measure was duration of noninvasive positive pressure ventilation following extubation with prolonged use defined as noninvasive positive pressure ventilation use for greater than 24 hours postextubation. Among 56 children, 47 (median age, 15.5 mo; interquartile range, 6-53 mo) had diaphragm thickness at end-expiration measured within 48 hours prior to extubation. Fourteen (30%) had prolonged noninvasive positive pressure ventilation use with median duration 110 hours (interquartile range, 52-130 hr). The median percentage change of diaphragm thickness at end-expiration from baseline among those with and without prolonged noninvasive positive pressure ventilation use was -20% (interquartile range, -32% to -10%) versus -7% (interquartile range, -21% to 0%) (p = 0.04).

CONCLUSIONS

Diaphragm atrophy is associated with prolonged postextubation noninvasive positive pressure ventilation in children with acute respiratory failure. Serial bedside diaphragm ultrasound may identify children at risk for prolonged noninvasive positive pressure ventilation use after extubation.

High Breath-by-Breath Variability Is Associated With Extubation Failure in Children

OBJECTIVES

Extubation failure is multifactorial, and most tools to assess extubation readiness only evaluate snapshots of patient physiology. Understanding variability in respiratory variables may provide additional information to inform extubation readiness assessments.

DESIGN

Secondary analysis of prospectively collected physiologic data of children just prior to extubation during a spontaneous breathing trial. Physiologic data were cleaned to provide 40 consecutive breaths and calculate variability terms, coefficient of variation and autocorrelation, in commonly used respiratory variables (i.e., tidal volume, minute ventilation, and respiratory rate). Other clinical variables included diagnostic and demographic data, median values of respiratory variables during spontaneous breathing trials, and the change in airway pressure during an occlusion maneuver to measure respiratory muscle strength (maximal change in airway pressure generated during airway occlusion [PiMax]). Multivariable models evaluated independent associations with reintubation and prolonged use of noninvasive respiratory support after extubation.

SETTING

Acute care, children's hospital.

PATIENTS

Children were included from the pediatric and cardiothoracic ICUs who were greater than 37 weeks gestational age up to and including 18 years who were intubated greater than or equal to 12 hours with planned extubation. We excluded children who had a contraindication to an esophageal catheter or respiratory inductance plethysmography bands.

INTERVENTIONS

Noninterventional study.

MEASUREMENTS AND MAIN RESULTS

A total of 371 children were included, 32 of them were reintubated. Many variability terms were associated with reintubation, including coefficient of variation and autocorrelation of the respiratory rate. After controlling for confounding variables such as age and neurologic diagnosis, both coefficient of variation of respiratory rate(p < 0.001) and low PiMax (p = 0.002) retained an independent association with reintubation. Children with either low PiMax or high coefficient of variation of respiratory rate had a nearly three-fold higher risk of extubation failure, and when these children developed postextubation upper airway obstruction, reintubation rates were greater than 30%.

CONCLUSIONS

High respiratory variability during spontaneous breathing trials is independently associated with extubation failure in children, with very high rates of extubation failure when these children develop postextubation upper airway obstruction.

Monitoring of Respiratory Muscle Function in Critically Ill Children

OBJECTIVES

This review discusses the different techniques used at the bedside to assess respiratory muscle function in critically ill children and their clinical applications.

DATA SOURCES

A scoping review of the medical literature on respiratory muscle function assessment in critically ill children was conducted using the PubMed search engine.

STUDY SELECTION

We included all scientific, peer-reviewed studies about respiratory muscle function assessment in critically ill children, as well as some key adult studies.

DATA EXTRACTION

Data extracted included findings or comments about techniques used to assess respiratory muscle function.

DATA SYNTHESIS

Various promising physiologic techniques are available to assess respiratory muscle function at the bedside of critically ill children throughout the disease process. During the acute phase, this assessment allows a better understanding of the pathophysiological mechanisms of the disease and an optimization of the ventilatory support to increase its effectiveness and limit its potential complications. During the weaning process, these physiologic techniques may help predict extubation success and therefore optimize ventilator weaning.

CONCLUSIONS

Physiologic techniques are useful to precisely assess respiratory muscle function and to individualize and optimize the management of mechanical ventilation in children. Among all the available techniques, the measurements of esophageal pressure and electrical activity of the diaphragm appear particularly helpful in the era of individualized ventilatory management.

Assessment of Common Criteria for Awake Extubation in Infants and Young Children

BACKGROUND

Practice patterns surrounding awake extubation of pediatric surgical patients remain largely undocumented. This study assessed the value of commonly used predictors of fitness for extubation to determine which were most salient in predicting successful extubation following emergence from general anesthesia with a volatile anesthetic in young children.

METHODS

This prospective, observational study was performed in 600 children from 0 to 7 yr of age. The presence or absence of nine commonly used extubation criteria in children were recorded at the time of extubation including: facial grimace, eye opening, low end-tidal anesthetic concentration, spontaneous tidal volume greater than 5 ml/kg, conjugate gaze, purposeful movement, movement other than coughing, laryngeal stimulation test, and oxygen saturation. Extubations were graded as Successful, Intervention Required, or Major Intervention Required using a standard set of criteria. The Intervention Required and Major Intervention Required outcomes were combined as a single outcome for analysis of predictors of success.

RESULTS

Successful extubation occurred in 92.7% (556 of 600) of cases. Facial grimace odds ratio, 1.93 (95% CI, 1.03 to 3.60; P = 0.039), purposeful movement odds ratio, 2.42 (95% CI, 1.14 to 5.12; P = 0.022), conjugate gaze odds ratio, 2.10 (95% CI, 1.14 to 4.01; P = 0.031), eye opening odds ratio, 4.44 (95% CI, 1.06 to 18.64; P= 0.042), and tidal volume greater than 5 ml/kg odds ratio, 2.66 (95% CI, 1.21 to 5.86; P = 0.015) were univariately associated with the Successful group. A stepwise increase in any one, in any order, of these five predictors being present, from one out of five and up to five out of five yielded an increasing positive predictive value for successful extubation of 88.3% (95% CI, 82.4 to 94.3), 88.4% (95% CI, 83.5 to 93.3), 96.3% (95% CI, 93.4 to 99.2), 97.4% (95% CI, 94.4 to 100), and 100% (95% CI, 90 to 100).

CONCLUSIONS

Conjugate gaze, facial grimace, eye opening, purposeful movement, and tidal volume greater than 5 ml/kg were each individually associated with extubation success in pediatric surgical patients after volatile anesthetic. Further, the use of a multifactorial approach using these predictors, may lead to a more rational and robust approach to successful awake extubation.

A multidisciplinary, video-based, curriculum for management of the intubated and surgical airway patient for a pediatric hospital in El Salvador

OBJECTIVE

Primary objective is to determine the rate of intubation with inappropriately sized endotracheal tubes (ETTs) in a pediatric intensive care unit (PICU) in El Salvador. Secondary objective is to determine effectiveness of a video-based curriculum to teach local providers on pediatric advanced airway management and surgical approach to patients requiring airway reconstruction.

METHODS

Data for 296 intubated pediatric patients was collected over a six month period in a 16-bed PICU in El Salvador. Results of a learning behavior assessment survey completed by local healthcare workers informed a curriculum to complement on-site education during annual surgical airway mission trips. The video-based curriculum addressed proper sizing and use of cuffed endotracheal tubes, care of the intubated child and perioperative considerations of the surgical airway patient. Providers completed pre and post-curriculum quizzes to measure knowledge acquisition.

RESULTS

Over 6-months, 281 patients were intubated. Sixty-three percent had improperly sized ETTs. Thirty-one percent had a failed or accidental extubation. All-cause mortality was 24%. One hundred and fifty-nine Salvadorian providers completed a learning behavior survey informing a video-based curriculum. Sixty-four providers completed the curriculum. Post-curriculum quiz scores increased by 18.7%. Surgeons, anesthesiologist, intensivists and speech pathologists demonstrated significant improvement (p < 0.05).

CONCLUSION

Nearly two-thirds of intubated patients in a PICU in El Salvador have improperly sized ETTs and one-third require reintubation following planned or accidental extubation. The development of this first of its kind video-based curriculum for critical care and surgical training regarding how to properly care for the intubated child is coupled with the development of a longitudinal database to record pediatric airway related morbidity and mortality in the largest pediatric hospital in El Salvador. This model and system can be used to track the reduction in airway related morbidity and mortality directly related to a systems based intervention both in El Salvador and then elsewhere.

Falha de extubação em unidade de terapia intensiva pediátrica: estudo de coorte retrospectivo

RESUMO Na unidade de terapia intensiva (UTI) pediátrica, a falha de extubação pode aumentar o risco de mortalidade. Este estudo objetivou: (1) verificar a taxa de falha de extubação na UTI pediátrica de um hospital público do município de Bauru (São Paulo, Brasil); (2) identificar a principal causa atribuída à falha de extubação; (3) avaliar se características como a idade e o tempo de ventilação mecânica invasiva (VMI) estão associadas à falha de extubação; (4) avaliar se o tempo de permanência na UTI e hospital é maior entre os pacientes que apresentaram falha de extubação. Foi realizado estudo de coorte retrospectivo com 89 pacientes internados de maio de 2017 até julho de 2018. Os resultados mostraram taxa de falha de extubação correspondente a 16%. A principal causa atribuída à falha de extubação foi o estridor laríngeo, totalizando 57% dos casos. A comparação intergrupos (sucesso vs. falha de extubação) não mostrou diferenças em relação à idade (p=0,294) e ao tempo de VMI (p=0,228). No entanto, observamos que o grupo falha de extubação apresentou maior tempo de UTI (p=0,000) e hospital (p=0,010). Desta forma, concluímos que a taxa de extubação está de acordo com a observada em outros estudos. O estridor laríngeo foi responsável por mais da metade dos casos de falha de extubação. Embora a idade e o tempo de VMI não tenham sido características associadas à falha de extubação, esta contribuiu para o maior período de permanência na UTI e no hospital.

A Phase II randomized controlled trial for lung and diaphragm protective ventilation (Real-time Effort Driven VENTilator management)

Lung Protective Mechanical Ventilation (MV) of critically ill adults and children is lifesaving but it may decrease diaphragm contraction and promote Ventilator Induced Diaphragm Dysfunction (VIDD). An ideal MV strategy would balance lung and diaphragm protection. Building off a Phase I pilot study, we are conducting a Phase II controlled clinical trial that seeks to understand the evolution of VIDD in critically ill children and test whether a novel computer-based approach (Real-time Effort Driven ventilator management (REDvent)) can balance lung and diaphragm protective ventilation to reduce time on MV. REDvent systematically adjusts PEEP, FiO₂, inspiratory pressure, tidal volume and rate, and uses real-time measures from esophageal manometry to target normal levels of patient effort of breathing. This trial targets 276 children with pulmonary parenchymal disease. Patients are randomized to REDvent vs. usual care for the acute phase of MV (intubation to first Spontaneous Breathing Trial (SBT)). Patients in either group who fail their first SBT will be randomized to REDvent vs usual care for weaning phase management (interval from first SBT to passing SBT). The primary clinical outcome is length of weaning, with several mechanistic outcomes. Upon completion, this study will provide important information on the pathogenesis and timing of VIDD during MV in children and whether this computerized protocol targeting lung and diaphragm protection can lead to improvement in intermediate clinical outcomes. This will form the basis for a larger, Phase III multi-center study, powered for key clinical outcomes such as 28-day ventilator free days. Clinical Trials Registration: NCT03266016.