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

Predicting extubation failure in preterm infants using lung ultrasound: a diagnostic accuracy study

OBJECTIVE

To determine the accuracy of pre-extubation lung ultrasound (LUS) to predict reintubation in preterm infants born <32 weeks' gestation.

DESIGN

Prospective diagnostic accuracy study.

SETTING

Two neonatal intensive care units.

METHODS

Anterior and lateral LUS was performed pre-extubation. The primary outcome was the accuracy of LUS scores (range 0-24) to predict reintubation within 72 hours. Secondary outcomes were accuracy in predicting (1) reintubation within 7 days, (2) reintubation stratified by postnatal age and (3) accuracy of lateral imaging only (range 0-12). Pre-specified subgroup analyses were performed in extremely preterm infants born <28 weeks' gestation. Cut-off scores, sensitivities and specificities were calculated using receiver operating characteristic analysis and reported as area under the curves (AUCs).

RESULTS

One hundred preterm infants with a mean (SD) gestational age of 27.4 (2.2) weeks and birth weight of 1059 (354) g were studied. Thirteen were subsequently reintubated. The AUC (95% CI) of the pre-extubation LUS score for predicting reintubation was 0.63 (0.45-0.80). Accuracy was greater in extremely preterm infants: AUC 0.70 (0.52-0.87) and excellent in infants who were <72 hours of age at the time of extubation: AUC 0.90 (0.77-1.00). Accuracy was poor in infants who were >7 days of age. Lateral imaging alone demonstrated similar accuracy to scanning anterior and lateral regions.

CONCLUSIONS

In contrast to previous studies, LUS was not a strong predictor of reintubation in preterm infants. Accuracy is increased in extremely preterm infants. Future research should focus on infants at highest risk of extubation failure and consider simpler imaging protocols.

TRIAL REGISTRATION NUMBER

Australian New Zealand Clinical Trials Registry: ACTRN12621001356853.

Predictors and Outcomes of Extubation Failure in Preterm Neonates: A Systematic Review

CONTEXT

Extubation failure (EF) is common in preterm neonates and may be associated with adverse outcomes.

OBJECTIVE

To systematically review and meta-analyze the existing literature on predictors and outcomes of EF in preterm neonates.

DATA SOURCES

MEDLINE, Epub Ahead of Print, In-Process & Other Non-Indexed Citations, Embase (OvidSP), CINAHL (EBSCOHost), and Cochrane Library (Wiley) from 1995 onward. The search strategy was developed by a reference librarian.

STUDY SELECTION

Experimental or observational studies reporting on predictors and/or outcomes related to EF (defined as reintubation within 7 days) in preterm neonates less than 37 weeks were eligible. Predictors included machine learning (ML) algorithms and lung ultrasound (LUS). Main outcome of interest was association of EF with mortality and/or bronchopulmonary dysplasia (BPD).

DATA EXTRACTION

Studies identified by the search strategy were screened based on title and abstract. Data from included studies were extracted independently by 2 authors, along with adjudication of risk of bias. RevMan Web was used to conduct meta-analyses.

RESULTS

Out of 8336 studies screened, 120 were included. Neonates with lower gestational age at birth, birthweight, postmenstrual age, and weight at extubation were more likely to experience EF. Higher level of pre-extubation respiratory support, indicated by lower pre-extubation pH and higher pre-extubation mean airway pressure, fraction of inspired oxygen, and Pco2 were associated with EF risk. ML models showed variable accuracy and lower external validity. LUS may be a promising predictor, though scoring systems varied. EF was associated with higher odds of mortality and/or BPD (pooled odds ratio [OR], 4.7; 95% CI, 2.84-7.76) as well as the individual components of the composite: mortality (pooled OR, 3.87; 95% CI, 2.35-6.36) and BPD (pooled OR, 3.27; 95% CI, 2.54-4.21).

LIMITATIONS

Associations were derived from unadjusted data, precluding a definitive causal relationship between EF and predictors/outcomes.

CONCLUSIONS

Lower gestational and chronological age and higher levels of pre-extubation ventilation support were associated with EF. ML models and LUS scores require further validation in larger studies. EF was associated with mortality and/or BPD.

Postmenstrual age at Extubation as a Risk Factor Associated With Respiratory-Related Reintubation Among Extremely Preterm Infants: A Retrospective Cohort Study

BACKGROUND

Previous studies that discussed risk factors associated with extubation failure among preterm infants may have underestimated extubation failures because they used short observation windows for detecting reintubations.

AIMS

To explore risk factors associated with reintubations among extremely preterm infants during hospitalization.

STUDY DESIGN

A single-center, retrospective cohort study.

SUBJECTS

Infants born < 28 weeks gestational age between January 1, 2018, and December 31, 2022.

OUTCOME MEASURES

We focused only on extubation failures associated with respiratory problems. We assessed risk factors by conducting multivariable logistic regression analyses using variables previously reported as risk factors associated with extubation failure among preterm infants.

RESULTS

Ninety-five infants with a median gestational age of 25.6 weeks were eligible, and of those, 33 infants (34.7%) experienced extubation failure. Reintubations within 7 days after extubation accounted for approximately three-quarters of whole reintubations (24 infants, 72.7%). Risk factors associated with extubation failure were partial pressure of carbon dioxide (PCO2) before extubation (adjusted odds ratio [OR], 1.07; 95% confidence interval [CI], 1.01-1.14; p = 0.023), fraction of inspired oxygen (FIO2) before extubation (adjusted OR, 2.97; 95% CI, 1.10-8.04; p = 0.032), and postmenstrual age (PMA) at extubation (adjusted OR, 0.90; 95% CI, 0.84-0.97; p = 0.004). The predictive model submitting these variables demonstrated an area under the curve of 0.802.

CONCLUSIONS

When evaluating extubation failures more precisely by adopting the longer period, we might need to consider not only respiratory status before extubation but also maturity at extubation to assess extubation readiness.

Predicting extubation failure in neonates: The role of lung ultrasound and corrected gestational age in safe weaning in the NICU

To evaluate the accuracy of the lung ultrasound score (LUS) in predicting ventilatory weaning failure during neonatal hospitalization in the NICU and to identify factors associated with weaning failure, including corrected gestational age (CGA). This prospective, longitudinal, pragmatic and observational cohort study included neonates on mechanical ventilation for at least 48 h. The primary outcome was the accuracy of lung ultrasound in predicting 3-day weaning failure, with the ROC curve used to determine the best LUS cutoff (sensitivity and specificity). Among 55 neonates, the pre-extubation LUS did not show statistical significance in predicting weaning failure (AUC 0.61; 95% CI: 0.46-0.76, p = 0,169). In the subgroup analysis, a score ≥ 4 suggests the need for ventilatory support after extubation (area under the curve [AUC] = 0.91, 95% CI: 0.80-1.0, p < 0.001) in neonates with GA ≥ 28 weeks. In extremely preterm infants, the pre-extubation LUS was not statistically significant in predicting weaning failure (AUC = 0.38, 95% CI: 0-0.77, p = 0.535). In contrast, CGA ≥ 28.7 weeks at extubation was predictor of successful weaning within 3 days (AUC = 0.95, 95% CI: 0.85-1.0, p < 0.001).

CONCLUSION

LUS show promise in predicting weaning failure, though its accuracy may be limited in extremely preterm infants, highlighting the need for further well-powered studies. CGA at extubation also emerges as a key consideration in this population, warranting confirmation through robust future research.

WHAT IS KNOWN

• Identifying the optimal timing for extubation is crucial, as both prolonged mechanical ventilation and failed extubation are linked to increased morbidity. • Lung ultrasound plays a well-established role in diagnosing various neonatal lung pathologies, allowing clinicians to make rapid, bedside decisions for the treatment of newborns.

WHAT IS NEW

• LUS appears to be accurate in predicting weaning failure, though its accuracy may be lower in extremely preterm infants. • In extremely preterm infants, CGA may play an important role in extubation decision-making. • These findings are hypothesis-generating and warrant further investigation in future studies.

Accuracy of lung ultrasound in predicting successful extubation in preterm infants born ≤ 25 weeks

OBJECTIVE

The aim of this study was to examine the predictive value of the lung ultrasound score (LUS) for successful extubation in preterm infants born at ≤25+6 weeks.

METHODS

This was a single-center, prospective cohort study. Preterm infants with gestational age (GA) ≤ 25+6 weeks who received invasive mechanical ventilation (IMV) for ≥72 h were included. Lung ultrasound was performed every day. Multivariate logistic regression analysis was used to evaluate factors that predict extubation outcomes.

RESULTS

Ninety-three infants with GA ≤ 25+6 weeks were included. The mean GA was 24.5 ± 1.2 weeks. Extubation failure occurred in 55 (59.1%) neonates, and success occurred in 38 (40.9%) neonates. The LUS was significantly lower in the successful group than in the failed group (24.0 ± 2.5 vs. 32.1 ± 3.1 p < 0.001). Logistic regression analysis showed that LUS was an independent predictor of successful extubation (odd ratio 0.15 [95% CI 0.045-0.508], P = 0.002). The area under the receiver operating characteristic curve was 0.98 (p < 0.001) for LUS, and a cutoff value of ≥ 28 had 94.6% sensitivity and 92.7% specificity in detecting extubation failure.

CONCLUSION

The LUS has good accuracy for predicting successful extubation in extremely preterm infants with GA ≤ 25+6 weeks.

Lung recruitment with HFOV versus VTV/AC in preterm infants with RDS

OBJECTIVES

To compare the effect of lung recruitment using high frequency ventilation versus volume targeted ventilation on duration of intubation as well as its effect on lung inflammation in preterm infants with respiratory distress syndrome.

METHODS

The study was conducted on a total of 40 preterm infants, 34 weeks gestational age or less, having RDS that needed intubation and mechanical ventilation within the first 72 h after their birth at the NICU of Mansoura University Children's Hospital during the period from July 2020 to July 2022. Infants included were randomly assigned into two groups, Group A who were subjected to LRM using HFOV (20 cases) and Group B who were subjected to LRM using VTV/AC (20 cases). TGF-β1 level was measured in BAL samples of all studied infants at two time points; before lung recruitment maneuver and at day 5 after lung recruitment or just before extubation if extubation occurs earlier than 5 days.

RESULTS

Lung recruitment maneuver had no significant effect on time to extubation. Both groups showed no significant difference in rate of prematurity complications nor delta change of TFG-β1 level in tracheal aspirate of those preterm infants measured before lung recruitment and five days after recruitment or at extubation when extubation occurred earlier.

CONCLUSIONS

Lung recruitment maneuver was not associated with significant difference between both groups of preterm infants. The results obtained from our study, being the first of its kind to compare the effect of lung recruitment, provide a promising research area for further investigations.

Ventilator variables predicting extubation readiness in extremely premature infants with prolonged mechanical ventilation: A retrospective observational study

BACKGROUND

The current generation of neonatal ventilators enables periodic storage of set, measured, and calculated ventilatory parameters.

DESIGN

Retrospective observational study.

OBJECTIVES

To evaluate and identify the ventilatory, demographic, and clinical pre-extubation variables that are significant for estimating extubation readiness.

METHODS

Eligible subjects included premature infants <33 weeks of gestation weaned from mechanical ventilation (MV) lasting >24 h. A total of 16 relevant ventilator variables, each calculated from 288 data points over 24 h, together with eight demographic and three clinical pre-extubation variables, were used to create the generalized linear model (GLM) for a binary outcome and the Cox proportional hazards model for time-to-event analysis. The achievement of a 120-h period without reintubation was defined as a successful extubation attempt (EA) within the binary outcome.

RESULTS

We evaluated 149 EAs in 81 infants with a median (interquartile range) gestational age of 25+2 (24+3-26+1) weeks. Of this, 90 EAs (60%) were successful while 59 (40%) failed. GLM identified dynamic compliance per kilogram, percentage of spontaneous minute ventilation, and postmenstrual age as significant independent positive variables. Conversely, dynamic compliance variability emerged as a significant independent negative variable for extubation success. This model enabled the creation of a probability estimator for extubation success with a good proportion of sensitivity and specificity (80% and 73% for a cut-off of 60%, respectively).

CONCLUSIONS

Ventilator variables reflecting lung mechanical properties and the ability to spontaneously breathe during MV contribute to better prediction of extubation readiness in extremely premature infants with chronic lung disease.

Predictive model development for premature infant extubation outcomes: development and analysis

BACKGROUND

Given the knowledge of the damage caused by prolonged invasive mechanical ventilation in premature newborns, withdrawing this support as quickly as possible is important to minimize morbidity. The aim of this study was to analyze the variables associated with extubation outcomes and to develop a predictive model for successful extubation in premature newborns.

METHODS

Data were obtained from a multicenter study involving six public maternity hospitals. The variables with the highest correlation to the extubation outcome were used to construct the predictive model through data analysis and machine learning methods, followed by training and testing of algorithms.

RESULTS

Data were collected from 405 premature newborns. The predictive model with the best metrics was trained and tested using the variables of gestational age, birth weight, weight at extubation, congenital infections, and time on invasive mechanical ventilation, based on 393 samples according to the extubation outcome (12 were discarded due to irretrievable missing data in important attributes). The model exhibited an accuracy of 77.78%, sensitivity of 79.41%, and specificity of 60%.

CONCLUSION

These variables generated a predictive model capable of estimating the probability of successful extubation in premature newborns.

IMPACT

Prolonged use of invasive mechanical ventilation in preterm newborns increases morbidity/mortality rates, emphasizing the importance of early withdrawal from invasive ventilatory support. However, the decision to extubate lacks tools with higher extubation outcome precision. The use of artificial intelligence through the construction of a predictive model can assist in the decision-making process for extubating preterm newborns based on real-world data. The implementation of this tool can optimize the decision to extubate preterm newborns, promoting successful extubation and reducing preterm newborns exposure to adverse events associated with extubation failure.

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.

Characteristics and Outcomes in Preterm Infants with Extubation Failure in the First Week of Life

OBJECTIVE

This study aimed to evaluate characteristics and outcomes in preterm infants with extubation failures in their first week of life.

STUDY DESIGN

Retrospective chart review of infants born between 24 and 27 weeks' gestational age at the Sharp Mary Birch Hospital for Women and Newborns between January 2014 and December 2020 who had an extubation attempt within the first 7 days of life. Infants that were successfully extubated were compared with those who required reintubation in the first 7 days. Maternal and neonatal outcome measures were analyzed.

RESULTS

A total of 215 extremely preterm infants had an extubation attempt in the first 7 days of life. Forty-six infants (21.4%) failed extubation and were reintubated within the first 7 days. Infants who failed extubation had a lower pH (p < 0.01), increased base deficit (p < 0.01), and more surfactant doses prior to first extubation (p < 0.01). Birth weight, Apgar scores, antenatal steroid doses, and maternal risk factors such as preeclampsia, chorioamnionitis, and duration of ruptured membranes were not different between success and failure groups. Rates of moderate to large patent ductus arteriosus (p < 0.01), severe intraventricular hemorrhage (p < 0.01), posthemorrhagic hydrocephalus (p < 0.05), periventricular leukomalacia (p < 0.01), and retinopathy of prematurity stage 3 or greater (p < 0.05) were higher in the failure group.

CONCLUSION

In this cohort of extremely preterm infants that failed extubation in the first week of life, there were as increased risk of multiple morbidities. Base deficit, pH, and number of surfactant doses prior to first extubation may be useful tools in predicting which infants are likely to have early extubation success, but this needs prospective study.

KEY POINTS

· Predicting extubation readiness in preterm infants remains challenging.. · Extubation failure is associated with multiple neonatal morbidities.. · Infant clinical characteristics may help predict extubation failure..

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.

Artificial intelligence in the NICU to predict extubation success in prematurely born infants

OBJECTIVES

Mechanical ventilation in prematurely born infants, particularly if prolonged, can cause long term complications including bronchopulmonary dysplasia. Timely extubation then is essential, yet predicting its success remains challenging. Artificial intelligence (AI) may provide a potential solution.

CONTENT

A narrative review was undertaken to explore AI's role in predicting extubation success in prematurely born infants. Across the 11 studies analysed, the range of reported area under the receiver operator characteristic curve (AUC) for the selected prediction models was between 0.7 and 0.87. Only two studies implemented an external validation procedure. Comparison to the results of clinical predictors was made in two studies. One group reported a logistic regression model that outperformed clinical predictors on decision tree analysis, while another group reported clinical predictors outperformed their artificial neural network model (AUCs: ANN 0.68 vs. clinical predictors 0.86). Amongst the studies there was an heterogenous selection of variables for inclusion in prediction models, as well as variations in definitions of extubation failure.

SUMMARY

Although there is potential for AI to enhance extubation success, no model's performance has yet surpassed that of clinical predictors.

OUTLOOK

Future studies should incorporate external validation to increase the applicability of the models to clinical settings.

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.

Positive pressure ventilation in the weaning of preterm newborns

BACKGROUND

Weaning from invasive mechanical ventilation (IMV) of preterm newborns (PTNB) is one of the critical stages of life support in the Neonatal Intensive Care Unit (NICU). Noninvasive positive pressure ventilation (NPPV) has been used to facilitate weaning from IMV and includes continuous positive airway pressure (CPAP) without or with inspiratory pressure support (bilevel NPPV). Nevertheless, there is little information about their adherence and success rate during weaning process.

METHODS

In this retrospective cohort study, weaning data from patients admitted to a NICU from the northeast region of Brazil were analyzed. Sample was composed of PTNB submitted to IMV and divided in two groups according to the weaning strategy adopted: bilevel NPPV or NCPAP. Weaning failure was defined as returning to IMV within less than 48 h after extubation.

RESULTS

Fifty-seven PTNB were included. Majority were females, had caesarean delivery, very low weight upon birth (760-1480 g) and neonatal hypoxemia scores (Apgar) <7 in the first minute. Respiratory distress syndrome occurred in 56.7% of PTNB whilst respiratory infections occurred in 35.1% of patients. Bilevel NPPV was the most chosen modality of weaning. No difference in success rate was found between bilevel NPPV and NCPAP (P=0.17).

CONCLUSIONS

In this study, the application of noninvasive ventilation in preterm newborns for weaning from IMV was similar success rate between bilevel NPPV and NCPAP.

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.

Accuracy of lung ultrasound in predicting extubation failure in neonates: A systematic review and meta-analysis

OBJECTIVE

To systematically review and meta-analyze the diagnostic accuracy of lung ultrasound score (LUS) in predicting extubation failure in neonates.

STUDY DESIGN

MEDLINE, COCHRANE, EMBASE, CINAHL, and clinicaltrials.gov were searched up to 30 November 2022, for studies evaluating the diagnostic accuracy of LUS in predicting extubation outcome in mechanically ventilated neonates.

METHODOLOGY

Two investigators independently assessed study eligibility, extracted data, and assessed study quality using the Quality Assessment for Studies of Diagnostic Accuracy 2 tool. We conducted a meta-analysis of pooled diagnostic accuracy data using random-effect models. Data were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We calculated pooled sensitivity and specificity, pooled diagnostic odds ratios with 95% confidence intervals (CI), and area under the curve (AUC).

RESULTS

Eight observational studies involving 564 neonates were included, and the risk of bias was low in seven studies. The pooled sensitivity and specificity for LUS in predicting extubation failure in neonates were 0.82 (95% CI: 0.75-0.88) and 0.83 (95% CI: 0.78-0.86), respectively. The pooled diagnostic odds ratio was 21.24 (95% CI: 10.45-43.19), and the AUC for LUS predicting extubation failure was 0.87 (95% CI: 0.80-0.95). Heterogeneity among included studies was low, both graphically and by statistical criteria (I2  = 7.35%, p = 0.37).

CONCLUSIONS

The predictive value of LUS in neonatal extubation failure may hold promise. However, given the current level of evidence and the methodological heterogeneity observed, there is a clear need for large-scale, well-designed prospective studies that establish standardized protocols for lung ultrasound performance and scoring.

REGISTRATION

The protocol was registered in OSF (https://doi.org/10.17605/OSF.IO/ZXQUT).

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.

Predictive factors for extubation success in very low and extremely low birth weight preterm infants

Background

Although invasive mechanical ventilation (IMV) has contributed to the survival of preterm infants with extremely low birth weight (ELBW), it is also associated with unsatisfactory clinical outcomes when used for prolonged periods. This study aimed to identify factors that may be decisive for extubation success in very low birth weight (VLBW) and extremely low birth weight (ELBW) preterm infants.

Methods

The cohort study included preterm infants with gestational age (GA) <36 weeks, birth weight (BW) <1500 grams who underwent IMV, born between 2015 and 2018. The infants were allocated into two groups: extubation success (SG) or failure (FG). A stepwise logistic regression model was created to determine variables associated with successful extubation.

Results

Eighty-three preterm infants were included. GA and post-extubation arterial partial pressure of carbon dioxide (PaCO2) were predictive of extubation success. Infants from FG had lower GA and BW, while those from SG had higher weight at extubation and lower post-extubation PaCO2.

Discussion

Although we found post-extubation PaCO2 as an extubation success predictor, which is a variable representative of the moment after the primary outcome, this does not diminish its clinical relevance since extubation does not implicate in ET removal only; it also involves all the aspects that take place within a specified period (72 hours) after the planned event.

Conclusion

GA and post-extubation PaCO2 were predictors for extubation success in VLBW and ELBW preterm infants. Infants who experienced extubation failure had lower birth weight and higher FiO2 prior to extubation.

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.

A Nomogram for Predicting Extubation Failure in Preterm Infants with Gestational Age Less than 29 Weeks

INTRODUCTION

How to avoid reintubations in prematurity remains a hard nut. This study aimed to develop and validate a nomogram for predicting extubation failure in preterm infants who received different modes of noninvasive ventilation as post-extubation support.

METHODS

This was a secondary analysis of pre-existing data from a large multicenter RCT combined with a multicenter retrospective investigation in three tertiary referral NICUs in China. The training cohort consisted of extubated infants from the RCT and the validation cohort included neonates admitted to the three NICUs in the last 5 years. The nomogram was developed through univariate and multivariate logistic regression analyses of peri-extubation clinical variables.

RESULTS

A total of 432 and 183 preterm infants (25 weeks ≤ gestational age [GA] <29 weeks) were, respectively, included in the training cohort and the validation cohort. Lower birth weight, lower Apgar 5-min score, lower postmenstrual age at extubation, lower PO2 and higher PCO2 before extubation, and continuous positive airway pressure rather than nasal intermittent positive pressure ventilation or noninvasive high-frequency oscillatory ventilation after extubation were associated with higher risks of extubation failure (p < 0.05), on which the nomogram was established. In both the training cohort and the validation cohort, the nomogram demonstrated good predictive accuracy (area under the receiver operating characteristic curve = 0.744 and 0.826); the Hosmer-Lemeshow test (p = 0.192 and 0.401) and the calibration curve (R2 = 0.195 and 0.307) proved a good fitness and conformity; and the decision curve analysis showed significant net benefit at the best threshold (p = 0.201).

CONCLUSION

This nomogram could serve as a good decision-support tool when predicting extubation failure in preterm infants with GA less than 29 weeks.

Autonomic markers of extubation readiness in premature infants

BACKGROUND

In premature infants, extubation failure is common and difficult to predict. Heart rate variability (HRV) is a marker of autonomic tone. Our aim is to test the hypothesis that autonomic impairment is associated with extubation readiness.

METHODS

Retrospective study of 89 infants <28 weeks. HRV metrics 24 h prior to extubation were compared for those with and without extubation success within 72 h. Receiver-operating curve analysis was conducted to determine the predictive ability of each metric, and a predictive model was created.

RESULTS

Seventy-three percent were successfully extubated. The success group had significantly lower oxygen requirement, higher sympathetic HRV metrics, and a lower parasympathetic HRV metric. α₁ (measure of autocorrelation, related to sympathetic tone) was the best predictor of success-area under the curve (AUC) of .73 (p = 0.001), and incorporated into a predictive model had an AUC of 0.81 (p < 0.0001)-sensitivity of 81% and specificity of 78%.

CONCLUSIONS

Extubation success is associated with HRV. We show an autonomic imbalance with low sympathetic and elevated parasympathetic tone in those who failed. α₁, a marker of sympathetic tone, was noted to be the best predictor of extubation success especially when incorporated into a clinical model.

IMPACT

This article depicts autonomic markers predictive of extubation success. We depict an autonomic imbalance in those who fail extubation with heightened parasympathetic and blunted sympathetic signal. We describe a predictive model for extubation success with a sensitivity of 81% and specificity of 78%.

Automated prediction of extubation success in extremely preterm infants: the APEX multicenter study

BACKGROUND

Extremely preterm infants are frequently subjected to mechanical ventilation. Current prediction tools of extubation success lacks accuracy.

METHODS

Multicenter study including infants with birth weight ≤1250 g undergoing their first extubation attempt. Clinical data and cardiorespiratory signals were acquired before extubation. Primary outcome was prediction of extubation success. Automated analysis of cardiorespiratory signals, development of clinical and cardiorespiratory features, and a 2-stage Clinical Decision-Balanced Random Forest classifier were used. A leave-one-out cross-validation was done. Performance was analyzed by ROC curves and determined by balanced accuracy. An exploratory analysis was performed for extubations before 7 days of age.

RESULTS

A total of 241 infants were included and 44 failed (18%) extubation. The classifier had a balanced accuracy of 73% (sensitivity 70% [95% CI: 63%, 76%], specificity 75% [95% CI: 62%, 88%]). As an additional clinical-decision tool, the classifier would have led to an increase in extubation success from 82% to 93% but misclassified 60 infants who would have been successfully extubated. In infants extubated before 7 days of age, the classifier identified 16/18 failures (specificity 89%) and 73/105 infants with success (sensitivity 70%).

CONCLUSIONS

Machine learning algorithms may improve a balanced prediction of extubation outcomes, but further refinement and validation is required.

IMPACT

A machine learning-derived predictive model combining clinical data with automated analyses of individual cardiorespiratory signals may improve the prediction of successful extubation and identify infants at higher risk of failure with a good balanced accuracy. Such multidisciplinary approach including medicine, biomedical engineering and computer science is a step forward as current tools investigated to predict extubation outcomes lack sufficient balanced accuracy to justify their use in future trials or clinical practice. Thus, this individualized assessment can optimize patient selection for future trials of extubation readiness by decreasing exposure of low-risk infants to interventions and maximize the benefits of those at high risk.

Prediction of extubation failure among low birthweight neonates using machine learning

OBJECTIVE

To develop machine learning models predicting extubation failure in low birthweight neonates using large amounts of clinical data.

STUDY DESIGN

Retrospective cohort study using MIMIC-III, a large single-center, open-source clinical dataset. Logistic regression and boosted-tree (XGBoost) models using demographics, medications, and vital sign and ventilatory data were developed to predict extubation failure, defined as reintubation within 7 days.

RESULTS

1348 low birthweight (≤2500 g) neonates who received mechanical ventilation within the first 7 days were included, of which 350 (26%) failed a trial of extubation. The best-performing model was a boosted-tree model incorporating demographics, vital signs, ventilator parameters, and medications (AUROC 0.82). The most important features were birthweight, last FiO2, average mean airway pressure, caffeine use, and gestational age.

CONCLUSIONS

Machine learning models identified low birthweight ventilated neonates at risk for extubation failure. These models will need to be validated across multiple centers to determine generalizability of this tool.

Validation of a non-invasive pressure-time index of the inspiratory muscles in spontaneously breathing newborn infants

To validate the pressure-time index of the inspiratory muscles as a non-invasive index of inspiratory muscle function in spontaneously breathing infants by comparing it against the gold-standard pressure-time index of the diaphragm. Prospective observational cohort study of consecutive infants breathing unsupported in room air in a tertiary neonatal intensive care unit, studied prior to discharge from neonatal care. The invasive pressure-time index of the diaphragm was calculated using a transdiaphragmatic dual-pressure catheter that measured transdiaphragmatic pressure by subtraction of the oesophageal from the gastric pressure. The non-invasive pressure-time index of the inspiratory muscles was calculated using pressure measurements at the level of the mouth via a differential pressure transducer connected to a face mask. Both indices were calculated as the product of the ratio of the mean inspiratory pressure divided by the maximum inspiratory pressure and the ratio of the inspiratory time divided by the total time of a respiratory cycle. One hundred and thirty infants (79 male) were included with a mean (SD) gestational age of 35.2 (3.2) weeks, studied at a median (IQR) postnatal age of 9 (6-20) days. The mean (SD) pressure-time index of the diaphragm was 0.063 (0.019) and the mean (SD) pressure-time index of the inspiratory muscles was 0.065 (0.023). The correlation coefficient for the two indices was 0.509 (p < 0.001). The mean (SD) absolute difference between the pressure-time index of the inspiratory muscles and pressure-time index of the diaphragm was 0.002 (0.021). In convalescent infants, the non-invasive pressure-time index of the inspiratory muscles had a moderate degree of correlation with the invasively derived pressure time index of the diaphragm measured with a transdiaphragmatic catheter.

Critical functional lung volumes in neonatal intensive care: evidence and clinical applications

Respiratory disease is common in premature and sick newborn infants and can often necessitate the initiation of intensive care. Newborn infants often suffer from conditions that are associated with decreased lung volumes that occur as a result of abnormal or incomplete lung development. Such conditions are prematurity and respiratory distress syndrome, preterm premature rupture of membranes and the ensuing pulmonary hypoplasia and congenital lung anomalies such as congenital diaphragmatic hernia. These diseases have a structural component manifesting with lower lung volumes and a functional component that can present with increased oxygen and ventilatory requirements. The corresponding decreased functional lung volume is possibly responsible for some unfavourable pulmonary outcomes. Some infants are unable to wean off invasive respiratory support and, in extreme cases, unable to sustain independent breathing that can lead to long-term invasive ventilation or subsequent death. The aim of this review is to summarise the available evidence behind the concept of a critical functional lung volume in neonatal intensive care and describe the clinical implications that arise from decreased functional lung volumes in the main high-risk populations of newborn infants. IMPACT: Newborn infants suffer from diseases such as respiratory distress syndrome, pulmonary hypoplasia and congenital diaphragmatic hernia that are associated with a decrease in the total lung volume and impaired lung function. Critically decreased functional lung volumes during neonatal care are associated with failure to wean off invasive respiratory support, increased mortality and possibly longer-term respiratory complications.

Age at First Extubation Attempt and Death or Respiratory Morbidities in Extremely Preterm Infants

OBJECTIVE

To describe the timing of first extubation in extremely preterm infants and explore the relationship between age at first extubation, extubation outcome, and death or respiratory morbidities.

STUDY DESIGN

In this subanalysis of a multicenter observational study, infants with birth weights of 1250 g or less and intubated within 24 hours of birth were included. After describing the timing of first extubation, age at extubation was divided into early (within 7 days from birth) vs late (days of life 8-35), and extubation outcome was divided into success vs failure (reintubation within 7 days after extubation), to create 4 extubation groups: early success, early failure, late success, and late failure. Logistic regression analyses were performed to evaluate associations between the 4 groups and death or bronchopulmonary dysplasia, bronchopulmonary dysplasia among survivors, and durations of respiratory support and oxygen therapy.

RESULTS

Of the 250 infants included, 129 (52%) were extubated within 7 days, 93 (37%) between 8 and 35 days, and 28 (11%) beyond 35 days of life. There were 93, 36, 59, and 34 infants with early success, early failure, late success, and late failure, respectively. Although early success was associated with the lowest rates of respiratory morbidities, early failure was not associated with significantly different respiratory outcomes compared with late success or late failure in unadjusted and adjusted analyses.

CONCLUSIONS

In a contemporary cohort of extremely preterm infants, early extubation occurred in 52% of infants, and only early and successful extubation was associated with decreased respiratory morbidities. Predictors capable of promptly identifying infants with a high likelihood of early extubation success or failure are needed.

Weaning and extubation from neonatal mechanical ventilation: an evidenced-based review

Mechanical ventilation is a lifesaving treatment used to treat critical neonatal patients. It facilitates gas exchange, oxygenation, and CO2 removal. Despite advances in non-invasive ventilatory support methods in neonates, invasive ventilation (i.e., ventilation via an endotracheal tube) is still a standard treatment in NICUs. This ventilation approach may cause injury despite its advantages, especially in preterm neonates. Therefore, it is recommended that neonatologists consider weaning neonates from invasive mechanical ventilation as soon as possible. This review examines the steps required for the neonate's appropriate weaning and safe extubation from mechanical ventilation.

Analysis of predictive parameters for extubation in very low birth weight preterm infants

BACKGROUND

Mechanical ventilation is the primary treatment for preterm infants with respiratory failure. Prolonged intubation may lead to complications; thus, early extubation is desirable. No standard criteria exist for determining the appropriateness of extubating very-low-birth-weight (VLBW) infants. This study explored the predictors of successful extubation in preterm VLBW infants.

METHODS

This retrospective cohort study included 60 preterm VLBW infants who underwent their first extubation in the neonatal intensive care unit in a regional hospital in Hsinchu, Taiwan, between January 2017 and November 2020. Successful extubation was defined as having no requirement of reintubation within 3 days of extubation. Potentially predictive variables, including demographics, prenatal characteristics, and ventilator parameters were compared between a successful extubation group and failed extubation group.

RESULTS

Of the 60 infants, 47 (78.33%) underwent successful extubation. The successful extubation group had higher Apgar scores at 1 (7 vs. 6, P = 0.02) and 5 min (9 vs. 7, P = 0.007) than those of the failed extubation group. Ventilator inspiratory pressure and mean airway pressure were significantly lower at 24, 16, 8, and 1 h before extubation and upon its completion in the successful extubation group. The areas under a number of the receiver operating characteristic curve curves in this study were moderate, specifically, 0.72, 0.74, and 0.69. Statistical analysis revealed an association between ventilator parameters before 1 h extubation (IP > 17.5cmH₂O, MAP >7.5 cmH₂O, RSS >1.82) and extubation failure (odds ratio 1.73, 2.27, 2.46 and 95% confidence interval:1.16-2.6, 1.26-4.08, 1.06-5.68, respectively).

CONCLUSION

Higher Apgar scores at birth, lower ventilator inspiratory pressure, and mean airway pressure 24, 16, 8, and 1 h and 1 h RSS prior to extubation are associated with successful extubation in VLBW preterm infants.

Cardiorespiratory measures shortly after extubation and extubation outcomes in extremely preterm infants

BACKGROUND

Nasal continuous positive airway pressure, nasal intermittent positive pressure ventilation, and non-invasive neurally adjusted ventilatory assist are modes of non-invasive respiratory support. The objective was to investigate if cardiorespiratory measures performed shortly after extubation are associated with extubation outcomes and predictors of extubation success.

METHODS

Randomized crossover trial of infants with birth weight (BW) ≤ 1250 g undergoing their first extubation. Shortly after extubation, electrocardiogram and electrical activity of the diaphragm (Edi) were recorded during 40 min on each mode. Measures of heart rate variability (HRV), diaphragmatic activity (Edi area, breath area and amplitude), and respiratory variability (RV) were computed on each mode and compared between infants with extubation success or failure (reintubation ≤ 7 days).

RESULTS

Twenty-three extremely preterm infants with median [IQR] gestational age 25.9 weeks [25.2-26.4] and BW 760 g [595-900] were included: 14 success and 9 failures. There were significant differences for HRV (very low-frequency power and sample entropy) and RV parameters (breath areas, amplitudes and expiratory times) between groups, with moderate strength (0.75-0.80 areas under ROC curves) in predicting success. Diaphragmatic activity measures were similar between groups.

CONCLUSIONS

In extremely preterm infants receiving non-invasive respiratory support shortly after extubation, several cardiorespiratory variability parameters were associated with successful extubation with moderate predictive accuracy.

IMPACT

Measures of cardiorespiratory variability, performed in extremely preterm infants while receiving NCPAP, NIPPV, and NIV-NAVA shortly after extubation, were significantly different between patients that succeeded or failed extubation. Cardiorespiratory variability measures had a moderate predictive accuracy for extubation success and can be potentially used as biomarkers, in recently extubated infants. Future investigations in this population may also consider including cardiorespiratory variability measures when assessing types of post-extubation respiratory support and promote individualized care.

Predictors of extubation success: a population-based study of neonates below a gestational age of 26 weeks

OBJECTIVE

The aim of the study was to investigate first extubation attempts among extremely premature (EP) infants and to explore factors that may increase the quality of clinical judgement of extubation readiness.

DESIGN AND METHOD

A population-based study was conducted to explore first extubation attempts for EP infants born before a gestational age (GA) of 26 weeks in Norway between 1 January 2013 and 31 December 2018. Eligible infants were identified via the Norwegian Neonatal Network database. The primary outcome was successful extubation, defined as no reintubation within 72 hours after extubation.

RESULTS

Among 482 eligible infants, 316 first extubation attempts were identified. Overall, 173 (55%) infants were successfully extubated, whereas the first attempt failed in 143 (45%) infants. A total of 261 (83%) infants were extubated from conventional ventilation (CV), and 55 (17%) infants were extubated from high-frequency oscillatory ventilation (HFOV). In extubation from CV, pre-extubation fraction of inspired oxygen (FiO₂) ≤0.35, higher Apgar score, higher GA, female sex and higher postnatal age were important predictors of successful extubation. In extubation from HFOV, a pre-extubation FiO₂ level ≤0.35 was a relevant predictor of successful extubation.

CONCLUSIONS

The correct timing of extubation in EP infants is important. In this national cohort, 55% of the first extubation attempts were successful. Our results suggest that additional emphasis on oxygen requirement, sex and general condition at birth may further increase extubation success when clinicians are about to extubate EP infants for the first time.

Weaning of invasive ventilation in the neonatal intensive care: Towards standardising practice: A narrative review

To present a physiological algorithmic approach to weaning of invasive ventilation in the neonatal intensive care, focusing mainly on the preterm infant. Review of literature, consensus guidelines, expert commentaries and practice guidelines from individual units. Weaning of ventilation for extubation in the neonatal population must follow certain criteria but needs individualising based on disease process, timeline and physiology. Algorithms based on scenarios and modes of ventilation used might aid the clinician on the floor for decision-making process.

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.

Respiratory muscle function in the newborn: a narrative review

Our aim was to summarise the current evidence and methods used to assess respiratory muscle function in the newborn, focusing on current and future potential clinical applications. The respiratory muscles undertake the work of breathing and consist mainly of the diaphragm, which in the newborn is prone to dysfunction due to lower muscle mass, flattened shape and decreased content of fatigue-resistant muscle fibres. Premature infants are prone to diaphragmatic dysfunction due to limited reserves and limited capacity to generate force and avoid fatigue. Methods to assess the respiratory muscles in the newborn include electromyography, maximal respiratory pressures, assessment for thoraco-abdominal asynchrony and composite indices, such as the pressure-time product and the tension time index. Recently, there has been significant interest and a growing body of research in assessing respiratory muscle function using bedside ultrasonography. Neurally adjusted ventilator assist is a novel ventilation mode, where the level of the respiratory support is determined by the diaphragmatic electrical activity. Prolonged mechanical ventilation, hypercapnia and hypoxia, congenital anomalies and systemic or respiratory infection can negatively impact respiratory muscle function in the newborn, while caffeine and synchronised or volume-targeted ventilation have a positive effect on respiratory muscle function compared to conventional, non-triggered or pressure-limited ventilation, respectively. IMPACT: Respiratory muscle function is impaired in prematurely born neonates and infants with congenital anomalies, such as congenital diaphragmatic hernia. Respiratory muscle function is negatively affected by prolonged ventilation and infection and positively affected by caffeine and synchronised compared to non-synchronised ventilation modes. Point-of-care diaphragmatic ultrasound and neurally adjusted ventilator assist are recent diagnostic and therapeutic technological developments with significant clinical applicability.

Respiratory management for extremely premature infants born at 22 to 23 weeks of gestation in proactive centers in Sweden, Japan, and USA

Survival of preterm newborn infants have increased steadily since the introduction of surfactant treatment and antenatal steroids. In the absence of randomized controlled trials on ventilatory strategies in extremely preterm infants, we present ventilatory strategies applied during the initial phase and the continued ventilatory care as applied in three centers with proactive prenatal and postnatal management and well documented good outcomes in terms of mortality and morbidity in this cohort of infants.

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.

Diaphragmatic electromyography during a spontaneous breathing trial to predict extubation failure in preterm infants

BACKGROUND

Premature attempts at extubation and prolonged episodes of ventilatory support in preterm infants have adverse outcomes. The aim of this study was to determine whether measuring the electrical activity of the diaphragm during a spontaneous breathing trial (SBT) could predict extubation failure in preterm infants.

METHODS

When infants were ready for extubation, the electrical activity of the diaphragm was measured by transcutaneous electromyography (EMG) before and during a SBT when the infants were on endotracheal continuous positive airway pressure.

RESULTS

Forty-eight infants were recruited (median (IQR) gestational age of 27.2 (25.6-30.4) weeks). Three infants did not pass the SBT and 13 failed extubation. The amplitude of the EMG increased during the SBT [2.3 (1.5-4.2) versus 3.5 (2.1-5.3) µV; p < 0.001]. In the whole cohort, postmenstrual age (PMA) was the strongest predictor for extubation failure (area under the curve (AUC) 0.77). In infants of gestational age <29 weeks, the percentage change of the EMG predicted extubation failure with an AUC of 0.74 while PMA was not associated with the outcome of extubation.

CONCLUSIONS

In all preterm infants, PMA was the strongest predictor of extubation failure; in those born <29 weeks of gestation, diaphragmatic electromyography during an SBT was the best predictor of extubation failure.

IMPACT

Composite assessments of readiness for extubation may be beneficial in the preterm population. Diaphragmatic electromyography measured by surface electrodes is a non-invasive technique to assess the electrical activity of the diaphragm. Postmenstrual age was the strongest predictor of extubation outcome in preterm infants. The change in diaphragmatic activity during a spontaneous breathing trial in extremely prematurely born infants can predict subsequent extubation failure with moderate sensitivity and specificity.

Decision to extubate extremely preterm infants: art, science or gamble?

In the modern era of neonatology, mechanical ventilation has been restricted to a smaller and more immature population of extremely preterm infants. Given the adverse outcomes associated with mechanical ventilation, every effort is made to extubate these infants as early as possible. However, the scientific basis for determining extubation readiness remains imprecise and primarily guided by clinical judgement, which is highly variable and subjective. In the absence of accurate tools to assess extubation readiness, many infants fail their extubation attempt and require reintubation, which also increases complications. Recent advances in the field have led to unravelling some of the complexities surrounding extubation in this population. This review aims to synthesise the available knowledge and provide a more evidence-based approach towards the reporting of extubation outcomes and assessment of extubation readiness in extremely preterm infants.

Early extubation is associated with shorter duration of mechanical ventilation and lower incidence of bronchopulmonary dysplasia

INTRODUCTION

Respiratory care of extremely preterm infants remains a challenge. The majority require invasive mechanical ventilation (MV), which is a contributing factor in developing bronchopulmonary dysplasia (BPD). It is important to keep MV to a minimum but there have been concerns that attempting extubation too early increases the risk for atelectasis, re-intubation, and further lung trauma. The aim of this study was to compare two different approaches to extubation.

METHODS

Single-center, retrospective cohort study including infants born at 22 + 0-25 + 6 weeks during 2005-2009 and 2011-2015, before and after implementing guidelines recommending delayed extubation. Primary outcomes were BPD, duration of MV and length of hospital stay.

RESULTS

Eighty-eight infants in the early era and 102 infants in the late era were included. Infants in the first period were younger at first extubation attempt, and a higher number of infants were extubated within 24 h, 72 h, and one week after birth. The number of infants re-intubated and postnatal age at re-intubation did not differ between the groups. The incidence of severe BPD was 28% in the early period compared to 48% in the later (p < 0.01). Infants in the late period had longer duration of MV (17 vs 27 days, p < 0.01) but similar length of hospital stay (118 vs 123, p = 0.21).

CONCLUSION

After implementing guidelines recommending delayed extubation, the incidence of severe BPD was higher and the duration of MV was longer. This supports the strategy to attempt extubation early even in extremely preterm infants.

Impact of early respiratory care for extremely preterm infants

Despite advances in neonatal intensive care, more than half of surviving infants born extremely preterm (EP; < 28 weeks' gestation) develop bronchopulmonary dysplasia (BPD). Prevention of BPD is critical because of its associated mortality and morbidity, including adverse neurodevelopmental outcomes and respiratory health in later childhood and beyond. The respiratory care of EP infants begins before birth, then continues in the delivery room and throughout the primary hospitalization. This chapter will review the evidence for interventions after birth that might improve outcomes for infants born EP, including the timing of umbilical cord clamping, strategies to avoid or minimize exposure to mechanical ventilation, modes of mechanical ventilation and non-invasive respiratory support, oxygen saturation targets, postnatal corticosteroids and other adjunct therapies.

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.

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.

Does a brief trial of endotracheal CPAP before extubation increase the work of breathing in preterm infants?

A brief period of endotracheal continuous positive airway pressure (ETT-CPAP) can predict extubation outcome but longer periods are associated with increased work of breathing and extubation failure. In ventilated preterm infants, brief ETT-CPAP does not increase the work of breathing and can be used to predict the outcome of extubation.

Predictors and outcomes of extubation failure in extremely preterm infants

AIM

To determine predictors and outcomes of extubation failure in extremely preterm (EP) infants born <28 weeks' gestational age (GA).

METHODS

Retrospective clinical audit across two tertiary-level neonatal intensive care units in Melbourne, Australia. Two-hundred and four EP infants who survived to their first extubation from mechanical ventilation. Extubation failure (re-intubation) within 7 days after the first extubation.

RESULTS

Lower GA (odds ratio [OR] 0.71, 95% confidence interval (CI), 0.61-0.89, P < 0.001) and higher pre-extubation measured mean airway pressure (MAP) on the mechanical ventilator (OR 1.9 [95% CI 1.41-2.51], P < 0.001) predicted extubation failure. The area under a receiver operating characteristic curve for GA and MAP was 0.77 (95% CI 0.70-0.82). After adjustment for GA, infants who experienced extubation failure had higher rates of bronchopulmonary dysplasia (P < 0.001), post-natal systemic corticosteroid treatment (P < 0.001), airway trauma (P < 0.003), longer durations of treatment with mechanical ventilation (P < 0.001), non-invasive respiratory support (P < 0.001), supplemental oxygen therapy (P = 0.05) and longer hospitalisation (P = 0.025).

CONCLUSIONS

Lower GA and higher pre-extubation measured MAP were predictive of extubation failure within 7 days in extremely preterm infants. Extubation failure was associated with increased morbidity and extended periods of respiratory support and hospitalisation.

Could myocardial function be predictive of successful extubation in newborns and infants?

OBJECTIVE

To investigate the relationship between cardiac function and extubation readiness in infants using speckle tracking echocardiography.

WORKING HYPOTHESIS

Cardiac function combined with established clinical parameters may better identify readiness for extubation.

STUDY DESIGN

Pilot prospective observational study.

PATIENT SELECTION

Mechanically ventilated infants were included.

METHODOLOGY

Cardiac function was assessed by echocardiography immediately before extubation. Systolic and diastolic function in the left (LV) and right ventricles (RV) were assessed by measurement of longitudinal strain (LS), and circumferential strain (CS) in the LV only. Pulmonary artery pressures were assessed using the velocity of tricuspid regurgitation jet (TR), septal position, and end-systolic eccentricity index (EI ES). Cases who extubated successfully (Group 1) were compared to cases who required reintubation (Group 2).

RESULTS

Twenty-five cases were included. LV CS and RV LS were significantly lower in those who required reintubation (Group 2) compared to those who were successfully extubated (Group 1) (LV CS, -21 (12)% vs. -33 (3)%, p = .001; RV LS -19 (2.7)% vs. -20 (2.5)%, p = .04). TR was absent in all cases. The septal shape was normal in 18 cases (72%), displaced to the left in 7 (28%) cases. No significant differences were found in LV EI ES between groups.