Role of spontaneous breathing trial in predicting successful extubation in premature infants

Using machine-learning models to predict extubation failure in neonates with bronchopulmonary dysplasia

AIM

To develop a decision-support tool for predicting extubation failure (EF) in neonates with bronchopulmonary dysplasia (BPD) using a set of machine-learning algorithms.

METHODS

A dataset of 284 BPD neonates on mechanical ventilation was used to develop predictive models via machine-learning algorithms, including extreme gradient boosting (XGBoost), random forest, support vector machine, naïve Bayes, logistic regression, and k-nearest neighbor. The top three models were assessed by the area under the receiver operating characteristic curve (AUC), and their performance was tested by decision curve analysis (DCA). Confusion matrix was used to show the high performance of the best model. The importance matrix plot and SHapley Additive exPlanations values were calculated to evaluate the feature importance and visualize the results. The nomogram and clinical impact curves were used to validate the final model.

RESULTS

According to the AUC values and DCA results, the XGboost model performed best (AUC = 0.873, sensitivity = 0.896, specificity = 0.838). The nomogram and clinical impact curve verified that the XGBoost model possessed a significant predictive value. The following were predictive factors for EF: pO2, hemoglobin, mechanical ventilation (MV) rate, pH, Apgar score at 5 min, FiO2, C-reactive protein, Apgar score at 1 min, red blood cell count, PIP, gestational age, highest FiO2 at the first 24 h, heart rate, birth weight, pCO2. Further, pO2, hemoglobin, and MV rate were the three most important factors for predicting EF.

CONCLUSIONS

The present study indicated that the XGBoost model was significant in predicting EF in BPD neonates with mechanical ventilation, which is helpful in determining the right extubation time among neonates with BPD to reduce the occurrence of complications.

Weaning from mechanical ventilation and assessment of extubation readiness

Tremendous advancements in neonatal respiratory care have contributed to the improved survival of extremely preterm infants (gestational age ≤ 28 weeks). While mechanical ventilation is often considered one of the most important breakthroughs in neonatology, it is also associated with numerous short and long-term complications. For those reasons, clinical research has focused on strategies to avoid or reduce exposure to mechanical ventilation. Nonetheless, in the extreme preterm population, 70-100% of infants born 22-28 weeks of gestation are exposed to mechanical ventilation, with nearly 50% being ventilated for ≥ 3 weeks. As contemporary practices have shifted towards selectively reserving mechanical ventilation for those patients, mechanical ventilation weaning and extubation remain a priority yet offer a heightened challenge for clinicians. In this review, we will summarize the evidence for different strategies to expedite weaning and assess extubation readiness in preterm infants, with a particular focus on extremely preterm infants.

Peri-extubation settings in preterm neonates: a systematic review and meta-analysis

OBJECTIVE

To systematically review: 1) peri-extubation settings; and 2) association between peri-extubation settings and outcomes in preterm neonates.

STUDY DESIGN

In this systematic review, studies were eligible if they reported patient-data on peri-extubation settings (objective 1) and/or evaluated peri-extubation levels in relation to clinical outcomes (objective 2). Data were meta-analyzed when appropriate using random-effects model.

RESULTS

Of 9681 titles, 376 full-texts were reviewed and 101 included. The pooled means of peri-extubation settings were summarized. For objective 2, three experimental studies were identified comparing post-extubation CPAP levels. Meta-analyses revealed lower odds for treatment failure [pooled OR 0.46 (95% CI 0.27-0.76); 3 studies, 255 participants] but not for re-intubation [pooled OR 0.66 (0.22-1.97); 3 studies, 255 participants] with higher vs. lower CPAP.

CONCLUSIONS

Summary of peri-extubation settings may guide clinicians in their own practices. Higher CPAP levels may reduce extubation failure, but more data on peri-extubation settings that optimize outcomes are needed.

Predictors of successful extubation from volume-targeted ventilation in extremely preterm neonates

OBJECTIVE

To identify variables associated with extubation success in extremely preterm neonates extubated from invasive volume-targeted ventilation.

STUDY DESIGN

We retrospectively evaluated 84 neonates ≤28 weeks' gestational age, on their first elective extubation. The primary outcome of successful extubation was defined as non-reintubation within seven days. We used multivariate logistic regression analysis.

RESULTS

We identified 58 (69%) neonates (mean gestational age of 26.5 ± 1.4 weeks, birthweight 921 ± 217 g) who met the primary outcome. Female sex (OR 1.15, 95% CI 1.01-9.10), higher pre-extubation weight (OR 1.29, 95% CI 1.05-1.59), and pH (OR 2.54, 95% CI 1.54-4.19), and lower pre-extubation mean airway pressure (MAP) (OR 0.49, 95% CI 0.33-0.73) were associated with successful extubation.

CONCLUSIONS

In preterm neonates, female sex, higher pre-extubation weight and pH, and lower pre-extubation MAP were predictors of successful extubation from volume-targeted ventilation. Evaluation of these variables will likely assist clinicians in selecting the optimal time for extubation in such vulnerable neonates.

Predictors of extubation failure in newborns: a systematic review and meta-analysis

Extubation failure (EF) is a significant concern in mechanically ventilated newborns, and predicting its occurrence is an ongoing area of research. To investigate the predictors of EF in newborns undergoing planned extubation, we conducted a systematic review and meta-analysis. A systematic literature search was conducted in PubMed, Web of Science, Embase, and Cochrane Library for studies published in English from the inception of each database to March 2023. The PRISMA guidelines were followed in all phases of this systematic review. The Risk of Bias Assessment for Nonrandomized Studies tool was used to assess methodological quality. Thirty-four studies were included, 10 of which were overall low risk of bias, 15 of moderate risk of bias, and 9 of high risk of bias. The studies reported 43 possible predictors in six broad categories (intrinsic factors; maternal factors; diseases and adverse conditions of the newborn; treatment of the newborn; characteristics before and after extubation; and clinical scores and composite indicators). Through a qualitative synthesis of 43 predictors and a quantitative meta-analysis of 19 factors, we identified five definite factors, eight possible factors, and 22 unclear factors related to EF. Definite factors included gestational age, sepsis, pre-extubation pH, pre-extubation FiO2, and respiratory severity score. Possible factors included age at extubation, anemia, inotropic use, mean airway pressure, pre-extubation PCO2, mechanical ventilation duration, Apgar score, and spontaneous breathing trial. With only a few high-quality studies currently available, well-designed and more extensive prospective studies investigating the predictors affecting EF are still needed. In the future, it will be important to explore the possibility of combining multiple predictors or assessment tools to enhance the accuracy of predicting extubation outcomes in clinical practice.

Optimal timing of extubation in preterm infants

In neonatal intensive care, endotracheal intubation is usually performed as an urgent or semi-urgent procedure in infants with critical or unstable conditions related to progressive respiratory failure. Extubation is not. Patients undergoing extubation are typically stable, with improved respiratory function. The key elements to facilitating extubation are to recognize improvement in respiratory status, promote weaning of mechanical ventilation, and accurately identify readiness for removal of the endotracheal tube. Therefore, extubation should be a planned and well-organized procedure. In this review, we will appraise the evidence for existing predictors of extubation readiness and provide patient-specific, pathophysiology-derived strategies to optimize the timing and success of extubation in neonates, with a focus on extremely preterm infants.

Development and validation of a prediction model for evaluating extubation readiness in preterm infants

Successful early extubation has advantages not only in terms of short-term respiratory morbidities and survival but also in terms of long-term neurodevelopmental outcomes in preterm infants. However, no consensus exists regarding the optimal protocol or guidelines for extubation readiness in preterm infants. Therefore, the decision to extubate preterm infants was almost entirely at the attending physician's discretion. We identified robust and quantitative predictors of success or failure of the first planned extubation attempt before 36 weeks of post-menstrual age in preterm infants (<32 weeks gestational age) and developed a prediction model for evaluating extubation readiness using these predictors. Extubation success was defined as the absence of reintubation within 72 h after extubation. This observational cohort study used data from preterm infants admitted to the neonatal intensive care unit of Seoul National University Bundang Hospital in South Korea between July 2003 and June 2019 to identify predictors and develop and test a predictive model for extubation readiness. Data from preterm infants included in the Medical Informative Medicine for Intensive Care (MIMIC-III) database between 2001 and 2008 were used for external validation. From a machine learning model using predictors such as demographics, periodic vital signs, ventilator settings, and respiratory indices, the area under the receiver operating characteristic curve and average precision of our model were 0.805 (95% confidence interval [CI], 0.802-0.809) and 0.917, respectively in the internal validation and 0.715 (95% CI, 0.713-0.717) and 0.838, respectively in the external validation. Our prediction model (NExt-Predictor) demonstrated high performance in assessing extubation readiness in both internal and external validations.

Feasibility of Endotracheal Extubation Evaluation Form in Predicting Successful Extubation in Neonatal Intensive Care Units: A Retrospective Study

Given the limited availability of evidence-based methods for assessing the timing of extubation in intubated preterm infants, we aimed to standardize the extubation protocol in this single-center, retrospective study. To accomplish this, we established an extubation evaluation form to assess the suitability of extubation in preterm infants. The form comprises six indicators: improved clinical condition, spontaneous breath rate ≥ 30 breaths per minute, peak inspiratory pressure (PIP) ≤ 15 cmH₂O, fraction of inspired oxygen (FiO₂) ≤ 30%, blood pH ≥ 7.2, and mixed venous carbon dioxide tension (PvCO₂) < 70 mmHg. Each positive answer is given one point, indicating a maximum of six points. We enrolled 41 intubated preterm infants (gestational age < 32 weeks, birth weight < 1500 g) who were receiving mechanical ventilation support for over 24 h. Among them, 35 were successfully extubated, and 6 were not. After completing the extubation evaluation form and adjusting for birth weight and postextubation device, we observed that the total score of the form was significantly associated with successful extubation; the higher the score, the greater the chance of successful extubation. Thus, we infer that the extubation evaluation form may provide a more objective standard for extubation assessment in preterm infants.

Predictors of extubation outcomes among extremely and very preterm infants: a retrospective cohort study

OBJECTIVE

To explore the clinical or sociodemographic predictors for both successful and failed extubation among Chinese extremely and very preterm infants METHODS: A retrospective cohort study was carried out among extremely and very preterm infants born at less than 32 weeks of gestational age (GA).

RESULTS

Compared with the infants who experienced extubation failure, the successful infants had higher birth weight (OR 0.997; CI 0.996-0.998), higher GA (OR 0.582; 95% CI 0.499-0.678), a caesarean section delivery (OR 0.598; 95% CI 0.380-0.939), a higher five-minute Apgar score (OR 0.501; 95% CI 0.257-0.977), and a higher pH prior to extubation (OR 0.008; 95% CI 0.001-0.058). Failed extubation was associated with older mothers (OR 1.055; 95% CI 1.013-1.099), infants intubated in the delivery room (OR 2.820; 95% CI 1.742-4.563), a higher fraction of inspired oxygen (FiO₂) prior to extubation (OR 5.246; 95% CI 2.540-10.835), higher partial pressure of carbon dioxide (PCO₂) prior to extubation (OR 7.820; 95% CI 3.725-16.420), and higher amounts of lactic acid (OR 1.478;95% CI 1.063-2.056).

CONCLUSIONS

Higher GA, higher pre-extubation pH, lower pre-extubation FiO₂ and PCO, and lower age at extubation are significant predictors of successful extubation among extremely and very preterm infants.

Accuracy of the spontaneous breathing trial using a combined CPAP + PSV model to predict extubation outcomes in very preterm infants

Background

Very preterm infants often require mechanical ventilation. However, objective criteria to predict the outcomes of extubation in very premature neonates remain lacking. The aim of this study was to investigate the accuracy of the spontaneous breathing trial (SBT) using a combined model of continuous positive airway pressure (CPAP) and low-level pressure support ventilation (PSV) to predict the extubation outcomes of preterm infants with gestational age < 32 weeks.

Methods

Preterm infants with gestational age < 32 weeks, birth weight < 1500 g and requiring mechanical ventilation were selected for the study. All infants underwent a 10-minute SBT using CPAP combined with low-level PSV prior to the planned extubation. Then, the infants were extubated within 1 h after SBT. The outcomes of extubation were considered successful if the neonates did not require reintubation 72 h after extubation.

Results

A total of 119 eligible preterm infants were enrolled in the study, with a median gestational age of 28.9 (27.1–30.3) weeks and a median birth weight of 1100 (900–1350) g. In total, 101 of all infants had successful extubation, 18 of whom failed and eventually had to be reintubated. Of the 102 infants who achieved SBT, 99 were successfully extubated, and 15 of the 17 infants who did not pass SBT had failed extubation. Finally, the diagnostic value for SBT could be assessed with a sensitivity of 98%, a specificity of 83.3%, a positive predictive value of 97.1% and a negative predictive value of 88.2%.

Conclusion

SBT using a combined CPAP + low-level PSV model can predict the outcomes of extubation in very preterm infants with high sensitivity and specificity.

Postextubation Noninvasive Ventilation in Respiratory Distress Syndrome: A Randomized Controlled Trial

OBJECTIVE

Successful extubation and prevention of reintubation remain primary goals in neonatal ventilation. Our aim was to compare three modalities of postextubation respiratory support-noninvasive positive pressure ventilation (NIPPV), nasal bilevel positive airway pressure (N-BiPAP), and nasal continuous positive airway pressure (NCPAP)-using the RAM cannula in preterm neonates with respiratory distress syndrome (RDS). Our secondary aim was to define the predictors of successful extubation.

STUDY DESIGN

A total of 120 preterm neonates (gestational age ≤35 weeks) with RDS who had undergone primary invasive ventilation were randomized to receive either NIPPV, N-BiPAP, or NCPAP. The incidence of respiratory failure in the first 48 hours postextubation, total days of invasive and noninvasive ventilation, duration of hospitalization, and mortality were measured and compared among the three different noninvasive support modalities.

RESULTS

There were no significant differences in the postextubation respiratory failure rates and the number of days of invasive as well as noninvasive ventilation among the three different support modalities (p > 0.05). The total number of days of mechanical ventilation and the duration of hospitalization were significantly higher in the N-BiPAP group than those in the NCPAP or NIPPV groups (p < 0.05). A gestational age of at least 29 weeks and a birth weight of at least 1.4 kg were predictive of successful extubation with a sensitivity of 98.2 and 85.3% and a specificity of 63.6 and 90.9%, respectively.

CONCLUSION

Longer durations of mechanical ventilation and hospitalization were observed with N-BiPAP as a noninvasive mode of ventilation, but there was no significant difference in the extubation failure rates among the three modalities. Gestational age and birth weight were shown to be independent predictors of successful extubation of preterm neonates with RDS.

KEY POINTS

· Successful extubation and reintubation prevention of preterms are primary goals in neonatal ventilation.. · NIPPV, N-BiPAP, and NCPAP could be used as postextubation noninvasive modes in preterm neonates.. · Gestational age and birth weight are independent predictors of successful extubation of preterms..

Risk factors for prolonged mechanical ventilation in neonates following gastrointestinal surgery

BACKGROUND

Prolonged mechanical ventilation (MV) should be avoided in neonates. Noninvasive ventilation (NIV) can facilitate weaning from MV but has risks for patients immediately following foregut surgery due to the potential risk of anastomotic leak. We evaluated the risk factors for prolonged MV following intestinal surgery in neonates.

METHODS

We retrospectively reviewed 253 neonates undergoing intestinal surgery in 2017-2018 to identify risk factors for prolonged MV, and determine the correlation between NIV and anastomotic leak in a tertiary neonatal intensive care unit that performs the greatest number of neonatal surgeries in Ontario.

RESULTS

The most common diagnoses were necrotizing enterocolitis/spontaneous intestinal perforation (NEC/SIP) 21%, intestinal atresia 16%, esophageal atresia/tracheoesophageal fistula 14%, ano-rectal malformation 13%, malrotation/volvulus 11%, gastroschisis 9% and omphalocele 4%. The median (IQR) duration of MV post-surgery was 3 (1-8) days with 25.7 % (n=65) of neonates on MV for >7 days. Compared to infants on MV post-surgery for ≤7 days, those with MV>7 days were of lower gestational age, birth weight and weight at surgery, but a higher proportion underwent stoma creation, had a longer duration of opioid administration and higher rates of moderate to severe bronchopulmonary dysplasia (BPD) and mortality (P<0.05). Generalized linear regression analysis showed lower gestational age (GA) and longer opioid administration were associated with longer duration of MV (P<0.001), but indication for surgery, weight at surgery and stoma creation didn't correlate with longer duration of MV (P>0.05). Of the 122 patients handled by one-stage resection with primary anastomosis, 22.1% (n=27) received NIV with 74.1% (n=20) commenced on NIV after 7 days post-surgery, anastomotic leak was detected in 2.5 % (3/122) patients and didn't correlate with NIV.

CONCLUSIONS

Lower GA and longer opioid administration were risk factors for prolonged MV in neonates following intestinal surgery. Further research is needed to investigate modifiable practices around pain assessment/ventilation in these patients, and the correlation between NIV and anastomotic leak.

Risk Factors of Extubation Failure in Intubated Preterm Infants at a Tertiary Care Hospital in Oman

Objectives

This study aimed to determine extubation failure (EF) rate among intubated preterm infants (<37 weeks gestational age [GA]) admitted to a tertiary care neonatal intensive care unit (NICU) in Oman and identify the risk factors associated with EF.

Methods

This retrospective study included all intubated preterm infants (<37 weeks GA) admitted to the NICU at Sultan Qaboos University Hospital (SQUH) from January 2013 to December 2017. EF was defined as reintubation within seven days of planned extubation. Demographics, ventilation parameters, blood gas values and other possible risk factors of EF were collected. Statistical analysis included comparisons between EF and extubation success (ES) groups and a binary logistic regression analysis.

Results

A total of 190 preterm infants were intubated during the study period with 140 eligible for analysis. A total of 106 infants (75.7%) were successfully extubated while 34 (24.3%) failed extubation. GA <28 weeks (P = 0.029), lower 1-minute Apgar score (P = 0.023) and patent ductus arteriosus diagnosis (P = 0.018) were significantly associated with EF. After the multivariate analysis, only GA <28 weeks predicted EF with an adjusted odds ratio of 2.621 (95% confidence interval: 1.118 - 6.146).

Conclusion

EF rate in preterm infants admitted at the NICU of SQUH was within international rates. GA <28 weeks was the only predictor of the identified extubation failure. Neonatal practitioners need to seriously consider extreme prematurity in the extubation process and consider implementing strategies to decrease extubation failure in this group of fragile infants.

Safety and efficacy of a novel double-lumen tracheal tube in neonates with RDS: A prospective cohort study

BACKGROUND

The purpose of this study was to assess the safety and efficacy of a new double-lumen tracheal tube for neonates, with a conventional tracheal tube as a control.

METHOD

Newborns with respiratory distress syndrome (RDS) requiring endotracheal intubation admitted to the tertiary neonatal intensive care unit (NICU) of Qujing Maternal and Child Healthcare Hospital in Yunnan Province between March 2021 and May 2022 were enrolled in this prospective cohort study. Outcome indicators related to effectiveness included mainly the number of intubations, duration of ventilation, duration of oxygenation, and length of stay; safety indicators included any clinical adverse effects during and after intubation. Appropriate stratified and subgroup analyses were performed according to the purpose of intubation, gestational age, and whether the drug was administered via endotracheal tube.

RESULT

A total of 101 neonates were included and divided into two groups based on the choice of tracheal tube: the conventional (n = 50) and new (n = 51) tracheal tube groups. There was no statistical difference between the two groups in terms of adverse effects during and after intubation (p > 0.05). In neonates who were mechanically ventilated without endotracheal surfactant therapy or newborns receiving InSurE technique followed by non-invasive ventilation, no significant differences were found between the two groups regarding any of the efficacy indicators (p > 0.05). However, for neonates on invasive mechanical ventilation, the new tracheal tube allowed for a significant reduction in the duration of mechanical ventilation (96.50[74.00, 144.00] vs. 121.00[96.00, 196.50] hours, p = 0.037) and total ventilation (205.71 ± 80.24 vs. 277.56 ± 117.84 h, p = 0.027), when used as a route for endotracheal drug delivery. Further analysis was performed according to gestational age for newborns requiring intratracheal surfactant administration during mechanical ventilation, and the data showed that for preterm infants, the new tracheal tube not only shortened the duration of mechanical ventilation (101.75 ± 39.72 vs. 155.50 ± 51.49 h, p = 0.026) and total ventilation (216.00 ± 81.60 vs. 351.50 ± 113.79 h, p = 0.010), but also demonstrated significant advantages in reducing the duration of oxygen therapy (9.75 ± 6.02 vs. 17.33 ± 8.43 days, p = 0.042); however, there was no statistical difference in efficacy outcomes between the two groups in full-term infants (p > 0.05).

CONCLUSION

The efficacy and safety of this new tracheal tube are promising in neonates with RDS, especially those requiring surfactant administration via a tracheal tube during mechanical ventilation. Given the limitations of this study, however, the clinical feasibility of this catheter needs to be further confirmed in prospective randomized trials with larger sample sizes.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/showproj.aspx?proj=122073.

Can Fraction of Inspired Oxygen Predict Extubation Failure in Preterm Infants?

Background: Prolonged mechanical ventilation in preterm infants may cause complications. We aimed to analyze the variables affecting extubation outcomes in preterm infants at high risk of extubation failure. Methods: This was a single-center, observational, retrospective study. Extubation failure was defined as survival with the need for reintubation within 72 h. Successfully extubated neonates (group 1) were compared to those with failed extubation (group 2). Multivariate logistic regression analysis evaluated factors that predicted extubation outcomes. Results: Eighty infants with a birth weight under 1000 g and/or gestational age (GA) under 28 weeks were included. Extubation failure occurred in 29 (36.2%) and success in 51 (63.8%) neonates. Most failures (75.9%) occurred within 24 h. Pre-extubation inspired oxygen fraction (FiO₂) of 27% had a sensitivity of 58.6% and specificity of 64.7% for extubation failure. Post-extubation FiO₂ of 32% had a sensitivity of 65.5% and specificity of 62.8% for failure. Prolonged membrane rupture (PROM) and high GA were associated with extubation success in multivariate logistic regression analysis. Conclusions: High GA and PROM were associated with extubation success. Pre- and post-extubation FiO₂ values were not significantly predictive of extubation failure. Further studies should evaluate if overall assessment, including ventilatory parameters and clinical factors, can predict extubation success in neonates.

Relationship Between the Respiratory Severity Score and Extubation Failure in Very-Low-Birth-Weight Premature Infants

Objective:

The objective of the study is to investigate the utility of the respiratory severity score (RSS), an easy-to-use, non-invasive respiratory failure assessment tool that does not require arterial blood sampling, for predicting extubation failure in very-low-birth-weight premature infants.

Methods:

Demographic characteristics, clinical course, and neonatal morbidities were retrospectively analyzed. Data were obtained from the files of infants who were admitted to our unit between February 2016 and September 2020, were born before 30 weeks’ gestation, and had a birth weight <1250 g. Extubation success was defined as no need for reintubation for 72 h after extubation. RSS and RSS/kg values before each patient’s first planned extubation were calculated. RSS values before extubation and risk factors for extubation failure were compared between infants in the successful and failed extubation groups.

Results:

Our study enrolled 142 infants who met the inclusion criteria. The extubation failure rate was 30.2% (43/142). Early gestation, low birth weight, male sex, high RSS, grade ≥3 intraventricular hemorrhage, late-onset sepsis, low weight at the time of extubation, and postmenstrual age at the time of extubation were identified as risk factors for extubation failure. In the logistic regression analysis including these risk factors, RSS/kg remained a significant risk factor, along with late-onset sepsis (OR 25.7 [95% CI: 5.70–115.76]; p<0.001). In the receiver operating characteristic analysis of RSS values, at a cutoff value of 2.13 (area under the curve: 82.5%), RSS/kg had 77% sensitivity and 78% specificity (p<0.001). The duration of mechanical ventilation and hospital stay were prolonged in infants with extubation failure. The incidence rates of stage ≥3 retinopathy of prematurity and stage ≥2 necrotizing enterocolitis were also higher.

Conclusions:

High RSS and RSS/kg values were closely associated with extubation failure and can be used as a non-invasive assessment tool to support clinical decision-making, and thus reduce the rate of extubation failure.

Accuracy of Spontaneous Breathing Trial Using ET-CPAP in Predicting Successful Extubation of Neonates

Objective: Extubation failure is common in mechanically ventilated neonates. Finding objective criteria for predicting successful extubation may help to reduce the incidence of failure and the length of mechanical ventilation (MV). We conducted this study to determine the accuracy of the spontaneous breathing trial (SBT) and lung function measurements in predicting successful extubation in neonates. Methodology: This cross-sectional validation study was conducted at a tertiary care neonatal intensive care unit (NICU) over 12 months from December 2019 to December 2020. Neonates intubated for >24 hours and considered ready for extubation were enrolled in the study. Neonates who met defined eligibility criteria underwent a three minutes SBT using endotracheal continuous positive airway pressure (ET-CPAP) before extubation. The primary clinical team was blinded to the results, and all neonates were extubated after SBT. Extubation was considered successful if patients remained extubated for 48 hours.

Results: Among the 107 infants, 77.5% (n=83) of infants passed the SBT. Of these, 78 were successfully extubated, giving the positive predictive value of 93.97%. The overall extubation success rate was 90% (n=96). The sensitivity and specificity of SBT were 81.2% and 54.5%, respectively. VE (ET-CPAP) and VE-ventilator at a cutoff of ≥238 ml and ≥143.7 ml have an area under the curve (AUC) of 0.77 and 0.75 respectively to predict successful extubation (p-value 0.003, 0.008 respectively). Conclusion: SBT predicts extubation success with pronounced accuracy. Therefore, we propose SBT as a valuable and crucial step that guides clinicians' decision-making regarding extubation preparedness or impending failure in neonates.

Diaphragmatic activity and neural breathing variability during a 5-min endotracheal continuous positive airway pressure trial in extremely preterm infants

BACKGROUND

Extremely preterm infants are often exposed to endotracheal tube continuous positive airway pressure (ETT-CPAP) trials to assess extubation readiness. The effects of ETT-CPAP trial on their diaphragmatic activity (Edi) and breathing variability is unknown.

METHODS

Prospective observational study enrolling infants with birth weight ≤1250 g undergoing their first extubation attempt. Diaphragmatic activity, expressed as the absolute minimum (Edi min) and maximum values (Edi max), area under the Edi signal, and breath-by-breath analyses for breath areas, amplitudes, widths, and neural inspiratory and expiratory times, were analyzed during mechanical ventilation (MV) and ETT-CPAP. Neural breathing variability of each of these parameters was also calculated and compared between MV and ETT-CPAP.

RESULTS

Thirteen infants with median (interquartile range) birth weight of 800 g [610-920] and gestational age of 25.4 weeks [24.4-26.3] were included. Diaphragmatic activity significantly increased during ETT-CPAP when compared to MV:Edi max (44.2 vs. 38.1 μV), breath area (449 vs. 312 μV·s), and amplitude (10.12 vs. 7.46 μV). Neural breathing variability during ETT-CPAP was characterized by increased variability for amplitude and area under the breath, and decreased for breath time and width.

CONCLUSIONS

A 5-min ETT-CPAP in extremely preterm infants undergoing extubation imposed significant respiratory load with changes in respiratory variability.

IMPACT

ETT-CPAP trials are often used to assess extubation readiness in extremely preterm infants, but its effects upon their respiratory system are not well known. Diaphragmatic activity analysis demonstrated that these infants are able to mount an important response to a short trial. A 5-min trial imposed a significant respiratory load evidenced by increased diaphragmatic activity and changes in breathing variability. Differences in breathing variability were observed between successful and failed extubations, which should be explored further in extubation readiness investigations. This type of trial cannot be recommended for preterm infants in clinical practice until clear standards and accuracy are established.

A Prediction Model of Extubation Failure Risk in Preterm Infants

Objectives: This study aimed to identify variables and develop a prediction model that could estimate extubation failure (EF) in preterm infants. Study Design: We enrolled 128 neonates as a training cohort and 58 neonates as a validation cohort. They were born between 2015 and 2020, had a gestational age between 25^0/7 and 29^6/7 weeks, and had been treated with mechanical ventilation through endotracheal intubation (MVEI) because of acute respiratory distress syndrome. In the training cohort, we performed univariate logistic regression analysis along with stepwise discriminant analysis to identify EF predictors. A monogram based on five predictors was built. The concordance index and calibration plot were used to assess the efficiency of the nomogram in the training and validation cohorts. Results: The results of this study identified a 5-min Apgar score, early-onset sepsis, hemoglobin before extubation, pH before extubation, and caffeine administration as independent risk factors that could be combined for accurate prediction of EF. The EF nomogram was created using these five predictors. The area under the receiver operator characteristic curve was 0.824 (95% confidence interval 0.748-0.900). The concordance index in the training and validation cohorts was 0.824 and 0.797, respectively. The calibration plots showed high coherence between the predicted probability of EF and actual observation. Conclusions: This EF nomogram was a useful model for the precise prediction of EF risk in preterm infants who were between 25^0/7 and 29^6/7 weeks' gestational age and treated with MVEI because of acute respiratory distress syndrome.

Accuracy of a spontaneous breathing trial for extubation of neonates

BACKGROUND

Prevalence of extubation failure in neonates may be up to 80%, but evidence to determine if a neonate is ready for extubation remains unclear. We aim to evaluate a spontaneous breathing trial accuracy with minimum pressure support to predict success in neonates' extubation and identify variables related to failures.

METHODS

This is a diagnostic accuracy study based on a cohort study in an intensive care unit with all eligible newborn infants subjected to invasive mechanical ventilation for at least 24 hours submitted to the trial for 10 minutes before extubations. The outcome was failures of extubations, considered if reintubation was needed until 72 hours.

RESULTS

The incidence of failure was 14.7%among 170 extubations. There were 145 successful extubations; of these, 140 also passed the trial with a sensitivity of 96.5%(95%CI: 92.1-98.9). Of the 25 extubations that eventually failed, 16 failed the test with a specificity of 64.0%(95%CI: 42.5-82.0). The negative predictive value was 76.2%, and the positive predictive value was 94%. In stratifying by weight, the accuracy was >98.7%for neonates weighting >2500 g, but 72.5%for those weighing <1250 g. Extubation failures occurred more frequently in smaller (p = 0.01), preterm infants (p = 0.17), with longer ventilation time (p = 0.05), and having a hemodynamically significant persistent arterial duct (p = 0.01), compared with infants whose extubation was successful.

CONCLUSION

The spontaneous breathing trial with minimum pressure support ventilation seems to predict extubation success with great accuracy in full-term and larger neonates.

Prediction of extubation success using the diaphragmatic electromyograph results in ventilated neonates

Objectives Extubation failure is common in infants and associated with complications. Methods A prospective study was undertaken of preterm and term born infants. Diaphragm electromyogram (EMG) was measured transcutaneously for 15-60 min prior to extubation. The EMG results were related to tidal volume (Tve) to calculate the neuroventilatory efficiency (NVE). Receiver operating characteristic curves (ROC) were constructed and areas under the ROCs (AUROC) calculated. Results Seventy-two infants, median gestational age 28 (range 23-42) weeks were included; 15 (21%) failed extubation. Infants successfully extubated were more mature at birth (p=0.001), of greater corrected gestational age (CGA) at extubation (p<0.001) and heavier birth weight (p=0.005) than those who failed extubation. The amplitude and area under the curve of the diaphragm EMG were not significantly different between those who were and were not successfully extubated. Those successfully extubated required a significantly lower inspired oxygen and had higher expiratory tidal volumes (Tve) and NVE. The CGA and Tve had AUROCs of 0.83. A CGA of >29.6 weeks had the highest combined sensitivity (86%) and specificity (80%) in predicting extubation success. Conclusions Although NVE differed significantly between those who did and did not successfully extubate, CGA was the best predictor of extubation success.

Assessment of Extubation Readiness Using Spontaneous Breathing Trials in Extremely Preterm Neonates

IMPORTANCE

Spontaneous breathing trials (SBTs) are used to determine extubation readiness in extremely preterm neonates (gestational age ≤28 weeks), but these trials rely on empirical combinations of clinical events during endotracheal continuous positive airway pressure (ET-CPAP).

OBJECTIVES

To describe clinical events during ET-CPAP and to assess accuracy of comprehensive clinical event combinations in predicting successful extubation compared with clinical judgment alone.

DESIGN, SETTING, AND PARTICIPANTS

This multicenter diagnostic study used data from 259 neonates seen at 5 neonatal intensive care units from the prospective Automated Prediction of Extubation Readiness (APEX) study from September 1, 2013, through August 31, 2018. Neonates with birth weight less than 1250 g who required mechanical ventilation were eligible. Neonates deemed to be ready for extubation and who underwent ET-CPAP before extubation were included.

INTERVENTIONS

In the APEX study, cardiorespiratory signals were recorded during 5-minute ET-CPAP, and signs of clinical instability were monitored.

MAIN OUTCOMES AND MEASURES

Four clinical events were documented during ET-CPAP: apnea requiring stimulation, presence and cumulative durations of bradycardia and desaturation, and increased supplemental oxygen. Clinical event occurrence was assessed and compared between extubation pass and fail (defined as reintubation within 7 days). An automated algorithm was developed to generate SBT definitions using all clinical event combinations and to compute diagnostic accuracies of an SBT in predicting extubation success.

RESULTS

Of 259 neonates (139 [54%] male) with a median gestational age of 26.1 weeks (interquartile range [IQR], 24.9-27.4 weeks) and median birth weight of 830 g (IQR, 690-1019 g), 147 (57%) had at least 1 clinical event during ET-CPAP. Apneas occurred in 10% (26 of 259) of neonates, bradycardias in 19% (48), desaturations in 53% (138), and increased oxygen needs in 41% (107). Neonates with successful extubation (71% [184 of 259]) had significantly fewer clinical events (51% [93 of 184] vs 72% [54 of 75], P = .002), shorter cumulative bradycardia duration (median, 0 seconds [IQR, 0 seconds] vs 0 seconds [IQR, 0-9 seconds], P < .001), shorter cumulative desaturation duration (median, 0 seconds [IQR, 0-59 seconds] vs 25 seconds [IQR, 0-90 seconds], P = .003), and less increase in oxygen (median, 0% [IQR, 0%-6%] vs 5% [0%-18%], P < .001) compared with neonates with failed extubation. In total, 41 602 SBT definitions were generated, demonstrating sensitivities of 51% to 100% (median, 96%) and specificities of 0% to 72% (median, 22%). Youden indices for all SBTs ranged from 0 to 0.32 (median, 0.17), suggesting low accuracy. The SBT with highest Youden index defined SBT pass as having no apnea (with desaturation requiring stimulation) or increase in oxygen requirements by 15% from baseline and predicted extubation success with a sensitivity of 93% and a specificity of 39%.

CONCLUSIONS AND RELEVANCE

The findings suggest that extremely preterm neonates commonly show signs of clinical instability during ET-CPAP and that the accuracy of multiple clinical event combinations to define SBTs is low. Thus, SBTs may provide little added value in the assessment of extubation readiness.

Use of extubation bundle including modified spontaneous breathing trial (SBT) to reduce the rate of reintubation, among preterm neonates ≤ 30 weeks

BACKGROUND

Respiratory support in the form of mechanical ventilation is a crucial intervention in premature neonates, with respiratory problems. However, prolonged mechanical ventilation and endotracheal intubation may be associated with major adverse effects. The ideal time for extubation is based on clinical and laboratory parameters assessed at the time of planned extubation. However, such parameters are not very objective, which makes extubation in NICUs a trial-and-error approach.

OBJECTIVE

This work was done to assess the use of extubation bundle including modified spontaneous breathing trial (SBT) (10 minutes) to reduce the rate of reintubation, among preterm neonates≤30 weeks who were mechanically ventilated and extubated to non-invasive ventilation in the NICU, Women's Wellness and Research Center (WWRC), Hamad Medical Corporation (HMC), Doha, Qatar.

METHODS

A prospective study based on the collection of data regarding preterm neonates≤30 weeks gestation admitted to the NICU, Women's Wellness and Research Center (WWRC), from January, 2015 to December, 2017, who were subjected to mechanical ventilation (MV) and extubation. When the clinical team decides a newborn is ready for extubation based on the extubation bundle, a modified SBT (10 min) is used.

RESULTS

This study included 465 premature babies from 24-≤30 weeks recruited in the NICU, Women's Wellness and Research Center (WWRC). Extubation bundle with modified SBT was able to predict success of extubation with 95% sensitivity and 90.4% Positive Predictive Value (PPV) in the gestational age (GA) group 24 -≤27 weeks (245) and 95.3% sensitivity and 90% PPV in the GA group > 27 -≤30 weeks (220). As expected, successfully extubated babies had a higher GA and weighed more at extubation, compared to babies who required re-intubation.

CONCLUSION

We recommend the extubation bundle with modified SBT prior to elective extubation to be used in predicting successful extubation in premature babies. Guidelines for extubation among premature babies are needed in order to reduce unnecessary exposure to adverse effects of mechanical ventilation.

Protocolized Versus Nonprotocolized Weaning to Reduce the Duration of Invasive Mechanical Weaning in Neonates: A Systematic Review of All Types of Studies

Mechanical ventilation is one of the most commonly used treatments in neonatology. Prolonged mechanical ventilation is associated with deleterious outcomes. To reduce the ventilation duration, weaning protocols have been developed to achieve extubation in adult and pediatric care in a safe and uniform manner. We performed a systematic review to obtain all available evidence on the effect of protocolized versus nonprotocolized weaning on the duration of invasive mechanical ventilation in critically ill neonates. The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, Web of Science, and the International Clinical Trial Registry Platform were searched until January 2018. Quantitative and qualitative studies involving neonates that investigated or described protocolized versus nonprotocolized weaning were included. Primary outcome was the difference in weaning duration. A total of 2099 potentially relevant articles were retrieved. Three studies met the inclusion criteria. Of 2 of these, the separate neonatal data could not be obtained. Only one retrospective study was included for this review. This reported a decrease in the mean weaning time from 18 to 5 and 6 days, respectively. There is no robust evidence in the literature to support or disprove the use of a weaning protocol in critically ill neonates.

A predictive model for extubation readiness in extremely preterm infants

OBJECTIVE

To develop an estimator for predicting successful extubation for an individual preterm infant.

STUDY DESIGN

This was a retrospective study that included infants with birth weights ≤1250 g, who were admitted to a tertiary NICU over a 7-year period, received mechanical ventilation and had an elective extubation attempt within 60 days of age. Perinatal and periextubation characteristics were compared in the successful and failed extubation groups.

RESULTS

Of 621 screened infants, 312 were included. Extubation succeeded in 73% and failed in 27%. Adjusted factors associated with successful extubation included greater gestational age, chronologic age, pre-extubation pH and lower pre-extubation FiO₂, along with lower "peak" respiratory severity score in the first 6 h of age.

CONCLUSIONS

We used readily available demographic and clinical data to create an extubation readiness estimator that provides the probability of extubation success for an individual preterm infant (http://elasticbeanstalk-us-east-2-676799334712.s3-website.us-east-2.amazonaws.com/).

Undersampling and Bagging of Decision Trees in the Analysis of Cardiorespiratory Behavior for the Prediction of Extubation Readiness in Extremely Preterm Infants

Extremely preterm infants often require endotracheal intubation and mechanical ventilation during the first days of life. Due to the detrimental effects of prolonged invasive mechanical ventilation (IMV), clinicians aim to extubate infants as soon as they deem them ready.Unfortunately, existing strategies for prediction of extubation readiness vary across clinicians and institutions, and lead to high reintubation rates. We present an approach using Random Forest classifiers for the analysis of cardiorespiratory variability to predict extubation readiness. We address the issue of data imbalance by employing random undersampling of examples from the majority class before training each Decision Tree in a bag. By incorporating clinical domain knowledge, we further demonstrate that our classifier could have identified 71% of infants who failed extubation, while maintaining a success detection rate of 78%.

Effects of an extubation readiness test protocol at a tertiary care fully outborn neonatal intensive care unit

Background and objectives

Extubation readiness testing (ERT) in the Neonatal Intensive Care Unit (NICU) is highly variable and lacking standardized criteria. To address this gap, an evidence-based, inter-professionally developed ERT protocol was implemented to assess effectiveness on extubation failure within 72 h and on duration of intubation (DOI).

Methods

A longitudinal retrospective chart review in a level III, fully outborn NICU, of intubated infants admitted 1-year prior (Group 1), and 1 year after implementation (Group 2). Patients were extubated if they passed a 2-stage ERT protocol (3 min continuous positive airway pressure (CPAP) followed by 7 min CPAP + pressure support). Descriptive, comparative statistics, and univariate and multiple logistic regression were completed on all patients and a ≤32 6/7 weeks subgroup (intubated at day-of-life 1); p < 0.05 is considered significant.

Results

All patients (n = 589 (n = 294 Group 1, n = 295 Group 2)) were included (preterm, intubated day of life one subgroup: n = 42 Group 1, n = 38 Group 2). For all patients, extubation failure decreased significantly from 9.9% to 4.1% (p = 0.006); Group 1 patients were 2.42 times more likely to experience extubation failure compared with Group 2. Extubation failure in the preterm subgroup decreased from 21.7% to 2.6% (p = 0.01); Group 1 patients were 10.71 times more likely to experience extubation failure. Median DOI was similar in both groups for all patients and in the preterm subgroup.

Conclusions

A unique two-stage ERT protocol was effective at reducing extubation failure rate, without increasing DOI, largely in preterm infants. The evidence-based, interprofessionally developed ERT protocol and its integration into the NICU culture largely contributed to its success.

Comparison of NIV-NAVA and NCPAP in facilitating extubation for very preterm infants

Background

Various types of noninvasive respiratory modalities that lead to successful extubation in preterm infants have been explored. We aimed to compare noninvasive neurally adjusted ventilatory assist (NIV-NAVA) and nasal continuous positive airway pressure (NCPAP) for the postextubation stabilization of preterm infants.

Methods

This retrospective study was divided into two distinct periods, between July 2012 and June 2013 and between July 2013 and June 2014, because NIV-NAVA was applied beginning in July 2013. Preterm infants of less than 30 weeks GA who had been intubated with mechanical ventilation for longer than 24 h and were weaned to NCPAP or NIV-NAVA after extubation were enrolled. Ventilatory variables and extubation failure were compared after weaning to NCPAP or NIV-NAVA. Extubation failure was defined when infants were reintubated within 72 h of extubation.

Results

There were 14 infants who were weaned to NCPAP during Period I, and 2 infants and 16 infants were weaned to NCPAP and NIV-NAVA, respectively, during Period II. At the time of extubation, there were no differences in the respiratory severity score (NIV-NAVA 1.65 vs. NCPAP 1.95), oxygen saturation index (1.70 vs. 2.09) and steroid use before extubation. Several ventilation parameters at extubation, such as the mean airway pressure, positive end-expiratory pressure, peak inspiratory pressure, and FiO₂, were similar between the two groups. SpO₂ and pCO₂ preceding extubation were comparable. Extubation failure within 72 h after extubation was observed in 6.3% of the NIV-NAVA group and 37.5% of the NCPAP group (P = 0.041).

Conclusions

The data in the present showed promising implications for using NIV-NAVA over NCPAP to facilitate extubation.

Predictors of extubation readiness in preterm infants: a systematic review and meta-analysis

CONTEXT

A variety of extubation readiness tests have already been incorporated into clinical practice in preterm infants.

OBJECTIVE

To identify predictor tests of successful extubation and determine their accuracy compared with clinical judgement alone.

METHODS

MEDLINE, Embase, PubMed, Cochrane Library and Web of Science were searched between 1984 and June 2016. Studies evaluating predictors of extubation success during a period free of mechanical inflations in infants less than 37 weeks' gestation were included. Risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. After identifying and describing all predictor tests, pooled sensitivity and specificity estimates for the different test categories were generated using a bivariate random-effects model.

RESULTS

Thirty-five studies were included, showing wide heterogeneities in population characteristics, methodologies and definitions of extubation success. Assessments ranged from a few seconds to 24 hours, provided 0-6 cmH₂O positive end-expiratory pressure and measured several clinical and/or physiological parameters. Thirty-one predictor tests were identified, showing good sensitivities but low and variable specificities. Given the high variation in test definitions across studies, pooling could only be performed on a subset. The commonly performed spontaneous breathing trials had pooled sensitivity of 95% (95% CI 87% to 99%) and specificity of 62% (95% CI 38% to 82%), while composite tests offered the best performance characteristics.

CONCLUSIONS

There is a lack of strong evidence to support the use of extubation readiness tests in preterm infants. Although spontaneous breathing trials are attractive assessment tools, higher quality studies are needed for determining the optimal strategies for improving their accuracy.

Non-invasive neurally adjusted ventilatory assist versus nasal intermittent positive-pressure ventilation in preterm infants born before 30 weeks' gestation

BACKGROUND

Non-invasive neurally adjusted ventilatory assist (NIV-NAVA), a mode of non-invasive ventilation (NIV) controlled by diaphragmatic electrical activity, may be superior to other NIV as a respiratory support after extubation in preterm infants, but no report has compared NIV-NAVA with other NIV methods. We evaluated the effectiveness and adverse effects of NIV-NAVA after extubation in preterm infants <30 weeks of gestation.

METHODS

This retrospective study involved patients who were born before 30 weeks of gestation. We mainly used NIV-NAVA or nasal intermittent positive-pressure ventilation (NIPPV) for preterm infants as the NIV after extubation and compared these two groups. The primary outcome was treatment failure. The secondary outcomes were extubation failure and adverse events. Treatment failure was defined as a change of NIV (NIPPV was switched to NIV-NAVA, or NIV-NAVA was switched to NIPPV) or reintubation ≤7 days after extubation.

RESULTS

Fifteen patients were in the NIV-NAVA group, and 19 were in the NIPPV group. The gestational age of the NIV-NAVA group was younger than that of the NIPPV group (25.7 ± 2.4 weeks vs 27.3 ± 1.8 weeks). Treatment failure occurred in six cases (40%) in the NIV-NAVA group and in nine cases (47.4%) in the NIPPV group, and no significant difference was demonstrated. No significant difference in adverse events was noted.

CONCLUSIONS

NIV-NAVA has advantages compared with NIPPV as the NIV for premature infants after extubation. NIV-NAVA can also be used safely without a significant difference in the rate of complications compared with NIPPV.

Impact of endotracheal tube biofilm and respiratory secretions on airway resistance and mechanics of breathing in a neonatal lung model

Endotracheal tube (ETT) obstruction from biofilm formation is a theoretical risk for intubated preterm neonates. The objective of this study is to determine the impact of ETT biofilm on ETT resistance and minute ventilation in a neonatal respiratory model. Postextubation 2.5- and 3.0-mm ETTs from ventilated preterm infants were matched with unused control ETTs. The pressure gradient across the ETT was measured at set flow rates and converted to airway resistance. Spontaneous breathing tests (SBTs) were performed using a virtual patient model and were considered “passed” if minute ventilation of patient ETTs was greater than 60% of control ETTs. Twenty-four 2.5-mm ETTs and sixteen 3.0-mm ETTs were analyzed. In both patient and control ETTs, as flow rate increases, the pressure gradient across the ETT also increases in a linear fashion. Resistance to flow in patient ETTs was statistically different from matched control ETTs ( P < 0.001), and patient ETTs had 19.9 cmH2O·l−1·sec−1 greater resistance than control ETTs. SBTs were performed in 27 of 40 ETTs. Twenty-six ETTs “passed” an SBT. In one obstructed 3.0-mm ETT, SBT measurements were unobtainable. The clinical impact of ETT biofilm as measured by a SBT appears to be minimal for the majority of patients in our study group. In 1 out of 27 ETTs, the presence of a biofilm significantly altered resistance to airflow and resulted in a failed SBT. Gas flow rate and ETT size had a greater impact on resistance to airflow and minute ventilation than ETT biofilm in this study sample.

NEW & NOTEWORTHY This is the first study to our knowledge to characterize the impact of endotracheal tube (ETT) biofilm and respiratory secretions on resistance to airflow in a neonatal ETT using a simulation neonatal lung model. Results show that the clinical impact of ETT biofilm is minimal for the majority of patients in our study group, and ETT obstruction from biofilm is an uncommon cause of respiratory decompensation in a preterm neonate.

Respiratory severity score and extubation readiness in very low birth weight infants

BACKGROUND

The respiratory severity score (RSS) is a byproduct of mean airway pressure (MAP) and fraction of inspired oxygen (FiO₂). We sought to determine whether RSS could be used as a screening tool to predict extubation readiness in very low birth weight (VLBW) infants.

METHODS

In a retrospective cohort study, medical records of all VLBW infants admitted to our unit (6/1/09-2/28/12) were reviewed for infants' demographics, prenatal characteristics, and medication use. Also, records were reviewed for unplanned vs. planned extubation, blood gas, ventilator parameters and signs of severe respiratory failure [RF, defined as partial pressure of carbon dioxide (pCO₂) > 65, pH < 7.20, FiO₂ > 50%, and MAP > 10 cm] on the day of extubation.

RESULTS

During the study period 31% (45/147) failed extubation. Overall, infants who failed extubation had a lower birth weight (BW) and gestational age (GA), and on the day of extubation had a higher RSS and percentage of having one or more signs of severe RF. In a logistic regression model, adjusting for BW, GA, RSS and RF, RSS remained the only risk factor associated with extubation failure [adjusted OR 1.63 (95% CI: 1.10-2.40); p = 0.01]. RSS had a sensitivity of 0.86 (95% CI: 0.72-0.94) at a cutoff of 1.26 and a specificity of 0.88 (95% CI: 0.80-0.94) at a cutoff of 2.5. There was no difference in extubation failure between unplanned vs. planned extubation [41% (9/22) vs. 29% (36/125); p = 0.25].

CONCLUSION

An elevated RSS is associated with extubation failure. Successful unplanned extubation is common in VLBW infants.

Markers of Successful Extubation in Extremely Preterm Infants, and Morbidity After Failed Extubation

OBJECTIVES

To identify variables associated with successful elective extubation, and to determine neonatal morbidities associated with extubation failure in extremely preterm neonates.

STUDY DESIGN

This study was a secondary analysis of the National Institute of Child Health and Human Development Neonatal Research Network's Surfactant, Positive Pressure, and Oxygenation Randomized Trial that included extremely preterm infants born at 24^0/7 to 27^6/7 weeks' gestation. Patients were randomized either to a permissive ventilatory strategy (continuous positive airway pressure group) or intubation followed by early surfactant (surfactant group). There were prespecified intubation and extubation criteria. Extubation failure was defined as reintubation within 5 days of extubation.

RESULTS

Of 1316 infants in the trial, 1071 were eligible; 926 infants had data available on extubation status; 538 were successful and 388 failed extubation. The rate of successful extubation was 50% (188/374) in the continuous positive airway pressure group and 63% (350/552) in the surfactant group. Successful extubation was associated with higher 5-minute Apgar score, and pH prior to extubation, lower peak fraction of inspired oxygen within the first 24 hours of age and prior to extubation, lower partial pressure of carbon dioxide prior to extubation, and non-small for gestational age status after adjustment for the randomization group assignment. Infants who failed extubation had higher adjusted rates of mortality (OR 2.89), bronchopulmonary dysplasia (OR 3.06), and death/ bronchopulmonary dysplasia (OR 3.27).

CONCLUSIONS

Higher 5-minute Apgar score, and pH prior to extubation, lower peak fraction of inspired oxygen within first 24 hours of age, lower partial pressure of carbon dioxide and fraction of inspired oxygen prior to extubation, and nonsmall for gestational age status were associated with successful extubation. Failed extubation was associated with significantly higher likelihood of mortality and morbidities.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT00233324.

Automated ongoing data validation and quality control of multi-institutional studies

This paper addresses the problem of ensuring the validity and quality of data in ongoing multi-disciplinary studies where data acquisition spans several geographical sites. It describes an automated validation and quality control procedure that requires no user supervision and monitors data acquired from different locations before analysis. The procedure is illustrated for the Automated Prediction of Extubation readiness (APEX) project in preterm infants, where acquisition of clinical and cardiorespiratory data occurs at 6 sites using different equipment and personnel. We have identified more than 40 problems with clinical information and 25 possible problems with the cardiorespiratory signals. Our validation and quality control procedure identifies these problems in an ongoing manner so that they can be timely addressed and corrected throughout this long-term collaborative study.

Prediction of Extubation readiness in extremely preterm infants by the automated analysis of cardiorespiratory behavior: study protocol

Background

Extremely preterm infants (≤ 28 weeks gestation) commonly require endotracheal intubation and mechanical ventilation (MV) to maintain adequate oxygenation and gas exchange. Given that MV is independently associated with important adverse outcomes, efforts should be made to limit its duration. However, current methods for determining extubation readiness are inaccurate and a significant number of infants fail extubation and require reintubation, an intervention that may be associated with increased morbidities. A variety of objective measures have been proposed to better define the optimal time for extubation, but none have proven clinically useful. In a pilot study, investigators from this group have shown promising results from sophisticated, automated analyses of cardiorespiratory signals as a predictor of extubation readiness. The aim of this study is to develop an automated predictor of extubation readiness using a combination of clinical tools along with novel and automated measures of cardiorespiratory behavior, to assist clinicians in determining when extremely preterm infants are ready for extubation.

Methods

In this prospective, multicenter observational study, cardiorespiratory signals will be recorded from 250 eligible extremely preterm infants with birth weights ≤1250 g immediately prior to their first planned extubation. Automated signal analysis algorithms will compute a variety of metrics for each infant, and machine learning methods will then be used to find the optimal combination of these metrics together with clinical variables that provide the best overall prediction of extubation readiness. Using these results, investigators will develop an Automated system for Prediction of EXtubation (APEX) readiness that will integrate the software for data acquisition, signal analysis, and outcome prediction into a single application suitable for use by medical personnel in the neonatal intensive care unit. The performance of APEX will later be prospectively validated in 50 additional infants.

Discussion

The results of this research will provide the quantitative evidence needed to assist clinicians in determining when to extubate a preterm infant with the highest probability of success, and could produce significant improvements in extubation outcomes in this population.

Trial registration

Clinicaltrials.gov identifier: NCT01909947. Registered on July 17 2013.

Trial sponsor: Canadian Institutes of Health Research (CIHR).

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0911-z) contains supplementary material, which is available to authorized users.

Risk Factors for Extubation Failure in Extremely Low Birth Weight Infants

BACKGROUND

Although antenatal steroids and early use nasal continuous positive airway pressure (NCPAP) have significantly improved outcomes of neonatal respiratory distress syndrome, intubation with ventilator support is still commonly required in extremely low birth weight (ELBW) infants. The optimal timing of extubation in ELBW infants remains unclear.

METHODS

We retrospectively analyzed all ELBW preterm infants who were admitted to our neonatal intensive care unit (NICU) from January 2009 to December 2013. Demographic, ventilation, and arterial blood gas analysis results prior to and 2 hours after extubation were collected. Extubation failure was defined as reintubation due to deterioration of respiratory condition within 7 days after extubation. Risk factors for extubation failure were analyzed.

RESULTS

In total, 173 ELBW infants were born and admitted to our NICU during these 5 years. Among these 173 infants, 77 (44.5%) used NCPAP only during their hospitalization (20 diagnosed with chronic lung disease (CLD), 25.9%). Among the 95 patients that required intubation, 27 patients expired so extubation was not attempted. Sixteen of 68 (23.5%) survival cases required reintubation within 7 days after extubation. We found that gestational age, birth body weight, and sex ratio did not differ between the successful extubation group and the failed extubation group. Univariate analysis showed that the failed extubation group had a lower arterial pH right before and 2 hours after extubation, with a lower bicarbonate level after extubation. Further multivariate logistic regression analysis revealed an association between poor acid-base homeostasis 2 hours after extubation (pH < 7.3 and HCO₃ < 18 mM/L) and extubation failure (odds ratio 4.56 and 6.187 and 95% confidence interval: 1.263∼16.462 and 1.68∼22.791, respectively).

CONCLUSION

This study shows that nearly half of ELBW infants do not require intubation. Among ELBW infants who require invasive ventilator support, those who have lower postextubation arterial pH and bicarbonate levels are at high risk of extubation failure.

Extubating Extremely Preterm Infants: Predictors of Success and Outcomes following Failure

OBJECTIVES

To identify variables that predict extubation success in extremely preterm infants born <28 weeks gestational age (GA), and to compare outcomes between those who had successful or failed extubation.

STUDY DESIGN

A secondary analysis of data from a randomized trial of postextubation respiratory support that included 174 extremely preterm infants. "Extubation success" was defined as not requiring reintubation within 7 days, and "extubation failure" the converse. Predictive variables that were different between groups were included in a multivariable logistic regression model.

RESULTS

Sixty-eight percent of infants were successfully extubated. Compared with those infants who had extubation failure, they had a higher GA and birth weight, were extubated earlier, were more often exposed to prolonged ruptured membranes, more often avoided intubation in the delivery room, had a higher pre-extubation pH, and had lower mean pre-extubation fraction of inspired oxygen and partial pressure of carbon dioxide (PCO2). Only GA and PCO2 remained significant in the multivariable analysis (area under a receiver operating characteristic curve = 0.81). Extubation failure was associated with death, bronchopulmonary dysplasia, severe retinopathy of prematurity, patent ductus arteriosus ligation, and longer durations of respiratory support, oxygen supplementation, and hospitalization. When adjusted for allocated treatment in the randomized trial, GA, and birth weight z-score, extubation failure remained associated with death before discharge and prolonged respiratory support and hospitalization.

CONCLUSIONS

In extremely preterm infants, higher GA and lower pre-extubation PCO2 predicted extubation success. Infants in whom extubation failed were more likely to die and have prolonged respiratory support and hospitalization.

TRIAL REGISTRATION

Australian New Zealand Clinical Trials Network: ACTRN12610000166077.

Monitoring the respiratory rate by miniature motion sensors in premature infants: a comparative study

OBJECTIVE

Existing respiratory rate (RR) monitors suffer from inaccuracy. The study assesses the accuracy of a novel modality that monitors lung ventilation with miniature motion sensors.

STUDY DESIGN

RR was measured by three methods: impedance technology, motion sensors and visual count, in babies (n=9) that breathed spontaneously or with respiratory support and babies (n=12) that received high-frequency oscillatory ventilation (HFOV).

RESULTS

A line close to equality (slope=0.96, r(2)=0.83) was obtained between the motion sensor and the visual count of the RR with narrow 95% limits of agreements (<14.0 b.p.m.). The relationship between the impedance and the visual count showed a lower correlation (r(2)=0.65) and wider 95% limits of agreements (21.4 b.p.m.). The motion sensor- and the ventilator-determined RRs demonstrated a good agreement during HFOV, whereas the impedance failed to measure the RR during HFOV.

CONCLUSION

Monitoring RR with motion sensors is more accurate compared with the impedance, in infants, in all ventilation modes.

Effects of Multiple Ventilation Courses and Duration of Mechanical Ventilation on Respiratory Outcomes in Extremely Low-Birth-Weight Infants

IMPORTANCE

Extubation failure is common in extremely preterm infants. The current paucity of data on the adverse long-term respiratory outcomes associated with reinitiation of mechanical ventilation prevents assessment of the risks and benefits of a trial of extubation in this population.

OBJECTIVE

To evaluate whether exposure to multiple courses of mechanical ventilation increases the risk of adverse respiratory outcomes before and after adjustment for the cumulative duration of mechanical ventilation.

DESIGN, SETTING, AND PARTICIPANTS

We performed a retrospective cohort study of extremely low-birth-weight (ELBW; birth weight <1000 g) infants born from January 1, 2006, through December 31, 2012, who were receiving mechanical ventilation. Analysis was conducted between November 2014 and February 2015. Data were obtained from the Alere Neonatal Database.

EXPOSURES

The primary study exposures were the cumulative duration of mechanical ventilation and the number of ventilation courses.

MAIN OUTCOMES AND MEASURES

The primary outcome was bronchopulmonary dysplasia (BPD) among survivors. Secondary outcomes were death, use of supplemental oxygen at discharge, and tracheostomy.

RESULTS

We identified 3343 ELBW infants, of whom 2867 (85.8%) survived to discharge. Among the survivors, 1695 (59.1%) were diagnosed as having BPD, 856 (29.9%) received supplemental oxygen at discharge, and 31 (1.1%) underwent tracheostomy. Exposure to a greater number of mechanical ventilation courses was associated with a progressive increase in the risk of BPD and use of supplemental oxygen at discharge. Compared with a single ventilation course, the adjusted odds ratios for BPD ranged from 1.88 (95% CI, 1.54-2.31) among infants with 2 ventilation courses to 3.81 (95% CI, 2.88-5.04) among those with 4 or more courses. After adjustment for the cumulative duration of mechanical ventilation, the odds of BPD were only increased among infants exposed to 4 or more ventilation courses (adjusted odds ratio, 1.44; 95% CI, 1.04-2.01). The number of ventilation courses was not associated with increased risk of supplemental oxygen use at discharge after adjustment for the length of ventilation. A greater number of ventilation courses did not increase the risk of tracheostomy.

CONCLUSIONS AND RELEVANCE

Among ELBW infants, a longer cumulative duration of mechanical ventilation largely accounts for the increased risk of chronic respiratory morbidity associated with reinitiation of mechanical ventilation. These results support attempts of extubation in ELBW infants receiving mechanical ventilation on low ventilator settings, even when success is not guaranteed.

International survey on periextubation practices in extremely preterm infants

OBJECTIVE

To determine periextubation practices in extremely preterm infants (<28 weeks gestation).

DESIGN

A survey consisting of 13 questions related to weaning from mechanical ventilation, assessment of extubation readiness and postextubation respiratory support was developed and sent to clinical directors of level III NICUs in Australia, Canada, Ireland, New Zealand and USA. A descriptive analysis of the results was performed.

RESULTS

112/162 (69%) units responded; 36% reported having a guideline (31%) or written protocol (5%) for ventilator weaning. Extubation readiness was assessed based on ventilatory settings (98%), blood gases (92%) and the presence of clinical stability (86%). Only 54% ensured that infants received caffeine ≤24 h prior to extubation. 16% of units systematically extubated infants on the premise that they passed a Spontaneous Breathing Test with a duration ranging from 3 min (25%) to more than 10 min (35%). Nasal continuous positive airway pressure was the most common type of respiratory support used (84%) followed by nasal intermittent positive pressure ventilation (55%) and high-flow nasal cannula (33%). Reintubation was mainly based on clinical judgement of the responsible physician (88%). There was a lack of consensus on the time frame for definition of extubation failure (EF), the majority proposing a period between 24 and 72 h; 43% believed that EF is an independent risk factor for increased mortality and morbidity.

CONCLUSIONS

Periextubation practices vary considerably; decisions are frequently physician dependent and not evidence based. The definition of EF is variable and well-defined criteria for reintubation are rarely used. High-quality trials are required to inform guidelines and standardise periextubation practices.

Correlation of clinical parameters with cardiorespiratory behavior in successfully extubated extremely preterm infants

Extremely preterm infants (gestational age ≤ 28 weeks) often require EndoTracheal Tube-Invasive Mechanical Ventilation (ETT-IMV) to survive. Clinicians wean infants off ETT-IMV as early as possible using their judgment and clinical information. However, assessment of extubation readiness is not accurate since 20 to 40% of preterm infants fail extubation. We extended our work in automated prediction of extubation readiness by examining correlations of automated cardiorespiratory features to clinical parameters in successfully extubated infants. Only a few features, mainly those related to variability of breathing synchrony, had any consistent correlation with clinical parameters, namely gestational age, day of life at extubation, and bicarbonate. We conclude that the automated cardiorespiratory features likely provide different information additional to clinical practice.

The implausibility of 'usual care' in an open system: sedation and weaning practices in Paediatric Intensive Care Units (PICUs) in the United Kingdom (UK)

Background

The power of the randomised controlled trial depends upon its capacity to operate in a closed system whereby the intervention is the only causal force acting upon the experimental group and absent in the control group, permitting a valid assessment of intervention efficacy. Conversely, clinical arenas are open systems where factors relating to context, resources, interpretation and actions of individuals will affect implementation and effectiveness of interventions. Consequently, the comparator (usual care) can be difficult to define and variable in multi-centre trials. Hence outcomes cannot be understood without considering usual care and factors that may affect implementation and impact on the intervention.

Methods

Using a fieldwork approach, we describe PICU context, ‘usual’ practice in sedation and weaning from mechanical ventilation, and factors affecting implementation prior to designing a trial involving a sedation and ventilation weaning intervention. We collected data from 23 UK PICUs between June and November 2014 using observation, individual and multi-disciplinary group interviews with staff.

Results

Pain and sedation practices were broadly similar in terms of drug usage and assessment tools. Sedation protocols linking assessment to appropriate titration of sedatives and sedation holds were rarely used (9 % and 4 % of PICUs respectively). Ventilator weaning was primarily a medical-led process with 39 % of PICUs engaging senior nurses in the process: weaning protocols were rarely used (9 % of PICUs). Weaning methods were variably based on clinician preference. No formal criteria or use of spontaneous breathing trials were used to test weaning readiness. Seventeen PICUs (74 %) had prior engagement in multi-centre trials, but limited research nurse availability. Barriers to previous trial implementation were intervention complexity, lack of belief in the evidence and inadequate training. Facilitating factors were senior staff buy-in and dedicated research nurse provision.

Conclusions

We examined and identified contextual and organisational factors that may impact on the implementation of our intervention. We found usual practice relating to sedation, analgesia and ventilator weaning broadly similar, yet distinctively different from our proposed intervention, providing assurance in our ability to evaluate intervention effects. The data will enable us to develop an implementation plan; considering these factors we can more fully understand their impact on study outcomes.

Application of NT-proBNP in ventilator weaning for preterm infants with RDS

OBJECTIVE

To evaluate the value of N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels along with spontaneous breathing trial (SBT) in the prediction of ventilator weaning outcome among respiratory distress syndrome (RDS) preterm infants ready to wean.

METHODS

NT-proBNP along with plasma albumin concentration, serum sodium, serum potassium, and hematocrit were measured immediately before SBT in preterm infants (≤32 weeks) mechanically ventilated due to RDS. Extubation was considered successful if infants remained extubated >48 hr. Either SBT failure or extubation failure was considered weaning failure.

RESULTS

Sixty-three of 88 infants passed the SBT and were subsequently extubated. Of these, two (3.2%) cases rapidly developed laryngeal dyspnea imposing reintubation (excluded from analysis). Of the remaining 61 infants, 45 (73.8%) cases had successful extubation, and 16 (26.2%) cases were reintubated. Infants who failed weaning had lower gestational age, birth weight, and plasma albumin concentrations, higher NT-proBNP, doses of surfactant, occurrence of ventilator-associated pneumonia, and occurrence of pulmonary arterial hypertension than those who did not. NT-proBNP was the only independent factor that could predict weaning failure (OR = 1.872; P = 0.044). The ROC-AUC for NT-proBNP to predict weaning failure was 0.977 (95% CI 0.918-0.997; P < 0.001). The cut-off of NT-proBNP level 18,500 pg/ml to predict weaning failure had a positive likelihood ratio of 25.180. The addition of NT-proBNP to SBT in prediction of weaning failure significantly improved the net reclassification improvement (NRI = 0.224; P = 0.034).

CONCLUSION

NT-proBNP is an independent factor that could predict weaning failure. Measurement of NT-proBNP prior to SBT may be helpful in promoting successful ventilator weaning along with SBT.