Impact of Spontaneous Breathing Trials in Cardiorespiratory Stability of Preterm Infants

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.

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.

Respiratory Management of the Preterm Infant: Supporting Evidence-Based Practice at the Bedside

Extremely preterm infants frequently require some form of respiratory assistance to facilitate the cardiopulmonary transition that occurs in the first hours of life. Current resuscitation guidelines identify as a primary determinant of overall newborn survival the establishment, immediately after birth, of adequate lung inflation and ventilation to ensure an adequate functional residual capacity. Any respiratory support provided, however, is an important contributing factor to the development of bronchopulmonary dysplasia. The risks correlated to invasive ventilatory techniques increase inversely with gestational age. Preterm infants are born at an early stage of lung development and are more susceptible to lung injury deriving from mechanical ventilation. Any approach aiming to reduce the global burden of preterm lung disease must implement lung-protective ventilation strategies that begin from the newborn’s first breaths in the delivery room. Neonatologists today must be able to manage both invasive and noninvasive forms of respiratory assistance to treat a spectrum of lung diseases ranging from acute to chronic conditions. We searched PubMed for articles on preterm infant respiratory assistance. Our narrative review provides an evidence-based overview on the respiratory management of preterm infants, especially in the acute phase of neonatal respiratory distress syndrome, starting from the delivery room and continuing in the neonatal intensive care unit, including a section regarding exogenous surfactant therapy.

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.

The Impact of Time Interval Between First Extubation and Reintubation on Bronchopulmonary Dysplasia or Death in Very Low Birth Weight Infants

OBJECTIVE

To explore the association between time from first extubation to reintubation and moderate-to-severe bronchopulmonary dysplasia (BPD) or death in very low birth weight infants.

STUDY DESIGN

Infants weighing <1,500 g at birth, requiring mechanical ventilation, and undergoing their initial extubation were retrospectively included from January 2014 to December 2021. They were divided into the moderate-to-severe BPD/death group and the comparison group according to the incidence of moderate-to-severe BPD or death. We defined time to reintubation as the time interval between first extubation and reintubation. In a stepwise multivariate logistic regression analysis, we examined the association between time to reintubation and moderate-to-severe BPD/death using different observation windows after initial extubation (24-h intervals).

RESULTS

A total of 244 infants were recruited, including 57 cases in the moderate-severe BPD/death group and 187 cases in the comparison group, and 93 (38.1%) cases were reintubated at least one time after their first extubation. Univariate analysis showed that reintubation rates within different observation windows in the moderate-to-severe BPD/death group were statistically significantly (p < 0.05) higher than those in the comparison group. Multivariate regression analysis showed that reintubation within observation windows 48 h or 72 h post-extubation was an independent risk factor in moderate-to-severe BPD/death and death, but not moderate-to-severe BPD. When the time window was 48 h, the probability of moderate-to-severe BPD/death [odds ratio (OR): 3.778, 95% confidence interval (CI): 1.293-11.039] or death (OR: 4.734, 95% CI: 1.158-19.354) was highest. While after extending the observation window to include reintubations after 72 h from initial extubation, reintubation was not associated with increased risk of moderate-to-severe BPD and/or death.

CONCLUSIONS

Not all reintubations conferred increased risks of BPD/death. Only reintubation within 72 h from initial extubation was independently associated with increased likelihood of moderate-to-severe BPD/death and death in very low birth weight infants, and reintubation within the first 48 h post-extubation posed the greatest risk.

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.