Prediction of extubation readiness using lung ultrasound in preterm infants

The Impact of Respiratory Therapist Performed Point-of-Care Lung Ultrasound on the Respiratory Care in Neonates, Manitoba Experience, Canada

OBJECTIVE

 We aimed to evaluate the impact of the registered respiratory therapist (RRT) performed point-of-care lung ultrasound (POC-LUS) on patient management in the neonatal intensive care unit (NICU).

STUDY DESIGN

 This is a retrospective cohort study of neonates who had RRT performed POC-LUS in two level III NICUs in Winnipeg, Manitoba, Canada. The analysis aims mainly to describe the implementation process of the POC-LUS program. The primary outcome was the prediction of the change in clinical management.

RESULTS

 A total of 136 neonates underwent 171 POC-LUS studies during the study period. POC-LUS resulted in a change in clinical management following 113 POC-LUS studies (66%), while it supported continuing the same management in 58 studies (34%). The lung ultrasound severity score (LUSsc) was significantly higher in the group with worsening hypoxemic respiratory failure and on respiratory support than infants on respiratory support and stable or not on respiratory support, p < 0.0001. LUSsc was significantly higher in infants on either noninvasive or invasive than those not on respiratory support, p-value <0.0001.

CONCLUSION

 RRT performed POC-LUS service utilization in Manitoba improved and guided the clinical management of a significant proportion of patients who received the service.

Prognostic Relevance of the Lung Ultrasound Score: A Multioutcome Study in Infants with Respiratory Distress Syndrome

OBJECTIVE

 There is growing evidence for the usefulness of the lung ultrasound score (LUS) in neonatal intensive care. We evaluated whether the LUS is predictive of outcomes in infants with respiratory distress syndrome (RDS).

STUDY DESIGN

 Neonates less than 34 weeks of gestational age were eligible for this prospective, multicenter cohort study. The outcomes of interest were the need for mechanical ventilation (MV) at <72 hours of life, the need for surfactant (SF), successful weaning from continuous positive airway pressure (CPAP), extubation readiness, and bronchopulmonary dysplasia. Lung scans were taken at 0 to 6 hours of life (Day 1), on Days 2, 3, and 7, and before CPAP withdrawal or extubation. Sonograms were scored (range 0-16) by a blinded expert sonographer. The area under the receiver operating characteristic curve (AUC) was used to estimate the prediction accuracy of the LUS.

RESULTS

 A total of 647 scans were obtained from 155 newborns with a median gestational age of 32 weeks. On Day 1, a cutoff LUS of 6 had a sensitivity (Se) of 88% and a specificity (Sp) of 79% to predict the need for SF (AUC = 0.86), while a cutoff LUS of 7 predicted the need for MV at <72 hours of life (Se = 89%, Sp = 65%, AUC = 0.80). LUS acquired prior to weaning off CPAP was an excellent predictor of successful CPAP withdrawal, with a cutoff level of 1 (Se = 67%, Sp = 100%, AUC = 0.86).

CONCLUSION

 The LUS has significant predictive ability for important outcomes in neonatal RDS.

KEY POINTS

· Lung ultrasound has significant prognostic abilities in neonatal RDS.. · Early sonograms (0-6 h of life) accurately predict the requirement for SF and ventilation.. · Weaning off CPAP is effective when the LUS (range 0-16) is less than or equal to 1..

Lung ultrasound score as a tool to predict severity of bronchopulmonary dysplasia in neonates born ≤25 weeks of gestational age

OBJECTIVE

The primary aim was to evaluate whether the addition of the posterior lung aided in diagnostic accuracy of predicting bronchopulmonary dysplasia (BPD) vs moderate-severe BPD (msBPD); the secondary aim was to explore the diagnostic accuracy of two protocols for BPD vs msBPD.

STUDY DESIGN

This was a single-center prospective observational study. Preterm infants with a gestational age ≤ 25 weeks were included. Two LUS score protocols were evaluated on the 14th day of life (DOL): (A) evaluating the anterolateral (LUS score-al) lung and (B) the anterolateral combined with posterior (LUS score-alp) lung. The LUS score range for the two protocols was 0-32 and 0-48, respectively.

RESULTS

A total of eighty-nine infants were enrolled. Both the LUS score-al and LUS score-alp were higher in neonates developing BPD and msBPD than in the rest of the cohort (LUS score-al 24 (23,26) vs 22 (20,23); LUS score-alp 36 (34,39) vs 28 (25,32)) (LUS score-al 25 (24,26) vs 23 (21,24); LUS score-alp 40 (39,40) vs 34 (28,36)). The LUS score-al on the 14th DOL showed a moderate diagnostic accuracy to predict BPD and msBPD (AUC 95% CI: 0.797 [0.697-0.896]; 0.811[0.713-0.909]), while the LUS score-alp significantly improved diagnostic accuracy of BPD and msBPD (AUC 95% CI: 0.902 [0.834-0.970]; 0.922 [0.848-0.996]). A cutoff of 25 points in the LUS score-al provided a sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 76.9%, 79.4%, 3.7, and 0.3 respectively to predict msBPD. Meanwhile, that of 39 points in the LUS score-alp provided a sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio of 81%, 98.4%, 50.5 and 0.19 to predict msBPD, respectively.

CONCLUSIONS

The LUS score on the 14th DOL can predict BPD and msBPD with moderate diagnostic accuracy. Apart from that, scanning posterior enhanced diagnostic accuracy.

Optimization of lung ultrasound in ultrafast-track anesthesia for non-cyanotic congenital heart disease surgery

Objective

We aimed to explore the feasibility of lung ultrasound for perioperative assessment and the optimal effect of lung ultrasound in reducing lung complications during non-cyanotic congenital heart disease (CHD) surgery using ultrafast-track anesthesia.

Methods

Sixty patients were treated at Shenzhen Children's Hospital between 2019 and 2020. Of these, 30 patients in group N had an indication for extubation and ultrafast-track anesthesia after congenital heart surgery; the tracheal catheter was removed, and the patients were sent to the cardiac intensive care unit (CICU) for further monitoring and treatment. Another 30 patients were in group L and also had an indication for extubation and ultrafast-track anesthesia; in addition we compared lung ultrasound score (LUS) before and after surgery, when we found the cases that LUS ≥ 15, for whom targeted optimization treatment would be carried out. The tracheal catheter was removed after LUS <15 days before the patients were sent to the CICU. In all cases, the LUS and PaO2/FiO2 ratios (P/F) of both groups were recorded at the time of anesthesia induction (T0), before extubation (T1), and 5 min (T2), 1 h (T3), and 24 h (T4) after extubation. The incidence of pulmonary complications, LUS, and P/F were compared between the two groups.

Results

There was great consistency between LUS and radiographic findings. Comparing the data of the two groups at T2, T3 and T4, the P/F was higher and the LUS was lower in group L than in group N. The incidence of lung complications in group L (18 cases, 60 %) was lower than that in group N (26 cases, 86.7 %, χ2 = 5.46, P = 0.02); comparing LUS between T0 and T3, LUS decreased in a greater number of cases in group L (15, 50 %) than in group N (7 cases, 23.3 %, χ2 = 4.59, P = 0.032).

Conclusion

Lung ultrasonography can effectively help assess lung conditions. Optimization guided by lung ultrasound in ultrafast track anesthesia can significantly reduce postoperative lung complications.

Accuracy of lung and diaphragm ultrasound in predicting infant weaning outcomes: a systematic review and meta-analysis

Background

Although lung and diaphragm ultrasound are valuable tools for predicting weaning results in adults with MV, their relevance in children is debatable. The goal of this meta-analysis was to determine the predictive value of lung and diaphragm ultrasound in newborn weaning outcomes.

Methods

For eligible studies, the databases MEDLINE, Web of Science, Cochrane Library, PubMed, and Embase were thoroughly searched. The Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) method was used to evaluate the study's quality. Results were gathered for sensitivity, specificity, diagnostic odds ratio (DOR), and the area under the curve of summary receiver operating characteristic curves (AUSROC). To investigate the causes of heterogeneity, subgroup analyses and meta-regression were conducted.

Results

A total of 11 studies were suitable for inclusion in the meta-analysis, which included 828 patients. The pooled sensitivity and specificity of lung ultrasound (LUS) were 0.88 (95%CI, 0.85-0.90) and 0.81 (95%CI, 0.75-0.87), respectively. The DOR for diaphragmatic excursion (DE) is 13.17 (95%CI, 5.65-30.71). The AUSROC for diaphragm thickening fraction (DTF) is 0.86 (95%CI, 0.82-0.89). The most sensitive and specific method is LUS. The DE and DTF were the key areas where study heterogeneity was evident.

Conclusions

Lung ultrasonography is an extremely accurate method for predicting weaning results in MV infants. DTF outperforms DE in terms of diaphragm ultrasound predictive power.

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.

Prediction of respiratory distress severity and bronchopulmonary dysplasia by lung ultrasounds and transthoracic electrical bioimpedance

This study aims to evaluate whether the assessment of a lung ultrasound score (LUS) by lung ultrasonography and of thoracic fluid contents (TFC) by electrical cardiometry may predict RDS severity and the development of bronchopulmonary dysplasia (BPD) in preterm infants with respiratory distress (RDS). Infants ≤ 34 weeks' gestation admitted with RDS to two neonatal intensive care units were prospectively enrolled in this observational study. A simultaneous evaluation of LUS and TFC was performed during the first 72 h. The predictivity of LUS and TFC towards mechanical ventilation (MV) need after 24 h and BPD development was evaluated using receiver operating characteristic analysis. Sixty-four infants were included. The area under the curve (AUC) for the prediction of MV need was 0.851 (95%CI, 0.776-0.925, p < 0.001) for LUS and 0.793 (95%CI, 0.724-0.862, p < 0.001) for TFC, while an AUC of 0.876 (95%CI, 0.807-0.946, p < 0.001) was obtained for combined LUS and TFC evaluation. LUS and TFC AUC for BPD prediction were 0.769 (95%CI, 0.697-0.842, p < 0.001) and 0.836 (95%CI, 0.778-0.894, p < 0.001), respectively, whereas their combined assessment yielded an AUC of 0.867 (95%CI, 0.814-0.919, p < 0.001). LUS ≥ 11 and TFC ≥ 40 were identified as cut-off values for MV need prediction, whereas LUS ≥ 9 and TFC ≥ 41.4 best predicted BPD development.   Conclusion: A combined evaluation of LUS and TFC by lung ultrasonography and EC during the first 72 h may represent a useful predictive tool towards short- and medium-term pulmonary outcomes in preterm infants with RDS. What is Known: • Lung ultrasonography is largely used in neonatal intensive care and can contribute to RDS diagnosis in preterm infants. • Little is known on the diagnostic and predictive role of TFC, measured by transthoracic electrical bioimpedance, in neonatal RDS. What is New: • Combining lung ultrasonography and TFC evaluation during the first 72 h can improve the prediction of RDS severity and BPD development in preterm infants with RDS and may aid to establish tailored respiratory approaches to improve these outcomes.

Accuracy of lung and diaphragm ultrasound in predicting successful extubation in extremely preterm infants: A prospective observational study

OBJECTIVE

Chest ultrasound has emerged as a promising tool in predicting extubation readiness in adults and children, yet its utility in preterm infants is lacking. Our aim was to assess the utility of lung ultrasound severity score (LUSS) and diaphragmatic function in predicting extubation readiness in extremely preterm infants.

STUDY DESIGN

In this prospective cohort study, preterm infants < 28 weeks gestational age (GA) who received invasive mechanical ventilation for ≥12 h were enrolled. Chest ultrasound was performed before extubation. The primary outcome was lung ultrasound accuracy for predicting successful extubation at 3 days. Descriptive statistics and logistic regression were done using SPSS version 22.

RESULTS

We enrolled 45 infants, of whom 36 (80%) were successfully extubated. GA and postmenstrual age (PMA) at extubation were significantly higher in the successful group. The LUSS was significantly lower in the successful group compared to failed group (11.9 ± 3.2 vs. 19.1 ± 3.1 p < 0.001). The two groups had no statistically significant difference in diaphragmatic excursion or diaphragmatic thickness fraction. Logistic regression analysis controlling for GA and PMA at extubation showed LUSS was an independent predictor for successful extubation (odd ratio 0.46, 95% confidence interval [0.23-0.9], p = 0.02). The area under the receiver operating characteristic curve was 0.95 (p ˂ 0.001) for LUSS, and a cut-off value of ≥15 had 95% sensitivity and 85% specificity in detecting extubation failure.

CONCLUSION

In extremely preterm infants, lung ultrasound has good accuracy for predicting successful extubation. However, diaphragmatic measurements were not reliable predictors.

Noninvasive high frequency oscillatory ventilation versus noninvasive positive pressure ventilation in preterm neonates after extubation: A randomized controlled trial

BACKGROUND

Weaning from mechanical ventilation is a challenging phase of neonatal respiratory support [1]. Choosing efficient and safe noninvasive modality to prevent re-intubation and choosing the optimal time for weaning are key points for weaning success. The aim of the study is to compare the efficiency and safety of noninvasive high frequency oscillatory ventilation (NHFOV) versus noninvasive positive pressure ventilation (NIPPV) as respiratory support after extubation in preterms with respiratory distress syndrome (RDS). Also, the study compared the lung ultrasound findings between these 2 modalities and assessed the use of lung ultrasound score (LUS) as predictor for extubation outcome.

METHODS

This study is a randomized controlled trial conducted on 60 preterm neonates with RDS. Patients were allocated into one of 2 groups: NIPPV or NHFOV as post-extubation noninvasive respiratory support. The 2 groups were compared regarding the incidence of extubation failure within 72 hours from extubation, oxygen needs, duration of application of the noninvasive modality, duration of admission, safety and mortality rate. LUS was assessed pre-extubation and 2 hours post-extubation.

RESULTS

The study did not show a statistically significant difference in re-ventilation rate in NHFOV group (23.3%) compared to NIPPV group (30.0%), p = 0.56. Oxygen needs were significantly lower in NHFOV group compared to NIPPV groups (mean FiO2 31.8±6.09 vs 38±0.55, p = 0.007). The duration of the used noninvasive modality, CO2 concentration, LUS, and mortality rate showed statistically insignificant difference between both groups. There was a significant correlation between LUS and extubation outcome.

CONCLUSION

NHFOV is a feasible noninvasive modality for respiratory support post-extubation in premature infants. LUS is a good predictor of extubation outcome in neonates.

Point of care lung ultrasound service in neonatal intensive care: Five years of experience in Manitoba, Canada

OBJECTIVE

To evaluate the utility of a point of care lung ultrasound (POC-LUS) on patient management in the Neonatal Intensive Care Unit (NICU).

STUDY DESIGN

A retrospective cohort study of neonates who had POC-LUS from 2016 to 2020 in two-level III NICUs in Winnipeg, Manitoba, Canada. The primary outcome was the change in clinical management. The analysis aims mainly to describe the implementation process of the POC-LUS program.

RESULTS

A total of 956 neonates underwent 4076 POC-LUS studies during the study period. The number of POC-LUS studies increased significantly every year, from 316 (in 2016) to 1257 (in 2020) (p < 0.001). POC-LUS resulted in a change in clinical management following 2528 POC-LUS studies (62%), while it supported continuing the same management in 1548 studies (38%).

CONCLUSION

POC-LUS in Manitoba increased since its inception and led to an alteration in the clinical management in a significant proportion of patients who received the service.

Prediction of weaning readiness off nasal CPAP in preterm infants using point-of-care lung ultrasound

This study's primary aim was to assess whether end-expiratory lung ultrasound severity score (expLUSsc) at Day 3 of life, the second week of life, and before weaning off nasal continuous positive airway pressure (nCPAP) can predict the weaning readiness off nCPAP trial in preterm infants. The secondary aim was to evaluate the value of adding lung tidal recruitment (LTR) to expLUSsc (expLUSsc-plus-LTR) to improve predictability. We conducted a prospective study on premature infants <33 weeks of gestation. Point-of-care lung ultrasound (POC-LUS) was performed on Day 3, the second week of life, before and after the trial off nCPAP. expLUSsc, pleural thickness, and LTR were assessed. A receiver operator curve was constructed to evaluate the ability of POC-LUS to predict the weaning readiness off nCPAP. A total of 148 studies were performed on 39 infants, of them 12 weaned off nCPAP from the first trial and 27 infants failed attempts off nCPAP. An expLUSsc cut-off 8 before the first trial of weaning off nCPAP has a sensitivity and specificity of 88% and 90%, and positive and negative predictive values of 87% and 92%, respectively, with area under the curve (AUC) was 0.87 (CI: 0.8-0.93), p < .0001. If LTR is added to an expLUSsc cut-off 8 (expLUSsc-plus-LTR) before the first trial of weaning, then sensitivity and specificity of 95% and 90%, and positive and negative predictive values of 88% and 90%, respectively, with AUC was 0.95 (CI: 0.91-0.99), p < .0001. In conclusion, this study demonstrated the ability of POC-LUS to predict the weaning readiness off nCPAP in premature infants. The use of this simple bedside noninvasive test can potentially avoid the exposure of premature infants to multiple unsuccessful weaning cycles.

Application of ultrasonography in neonatal lung disease: An updated review

Lung disease is often life-threatening for both preterm and term newborns. Therefore, an accurate and rapid diagnosis of lung diseases in newborns is crucial, as management strategies differ with different etiologies. To reduce the risk of radiation exposure derived from the conventionally used chest x-ray as well as computed tomography scans, lung ultrasonography (LUS) has been introduced in clinical practice to identify and differentiate neonatal lung diseases because of its radiation-free characteristic, convenience, high accuracy, and low cost. In recent years, it has been proved that LUS exhibits high sensitivity and specificity for identifying various neonatal lung diseases. Here, we offer an updated review of the applications of LUS in neonatal lung diseases based on the reports published in recent years (2017 to present).

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.