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

N-Terminal Pro-B Type Natriuretic Peptide as a Predictive Biomarker of Bronchopulmonary Dysplasia or Death Due to Bronchopulmonary Dysplasia in Preterm Neonates: A Systematic Review and Meta-Analysis

BACKGROUND

Emerging evidence suggests the clinical utility of N terminal pro B type natriuretic peptide (NT-proBNP) in multiple cardiac and pulmonary abnormalities both in adult and pediatric populations. To date, however, there is no consensus regarding its efficacy for the prediction and severity of bronchopulmonary dysplasia in premature neonates. The objective of the present meta-analysis was to determine differences in NT-proBNP among neonates that develop BPD or die from BPD and to evaluate if there is relative information on the diagnostic accuracy of the method.

METHODS

We conducted a systematic search according to the PRISMA guidelines and looked into Medline (1966-2023), Scopus (2004-2023), Clinicaltrials.gov (2008-2023), EMBASE (1980-2023), Cochrane Central Register of Controlled Trials CENTRAL (1999-2022) and Google Scholar (2004-2023) together with the reference lists from included studies. The potential risk of bias encountered in our study was evaluated using the QUADAS -2 tool. Finally, a total of 9 studies met the eligibility criteria, comprising 1319 newborns, from which 397 developed BPD and 922 were unaffected controls.

RESULTS

The results retrieved from our meta-analysis showed that newborns suffering from BPD had notably elevated NT-proBNP levels after birth when compared with healthy neonates (SMD 2.57, 95% CI 0.41, 4.72). The summary effect of the AUC meta-analysis showed that NT-proBNP was very accurate in detecting neonates at risk of developing severe BPD or dying from the disease (AUC -0.16, 95% CI -0.23, -0.08). No studies reported data relevant to the sensitivity and/or specificity of the method in diagnosing BPD.

CONCLUSION

Serum NT-proBNP levels represent a potential future biomarker with great diagnostic validity for the prediction of BPD complicating preterm deliveries. The limited amount of studies included and the significant variations in cutoff values and timing of measurement still restrict the application of NT-proBNP as an established clinical biomarker for BPD. The design of larger prospective studies will provide a more representative number of participants and will address the discrepancies in existing literature.

NT-proBNP and Zlog-transformed NT-proBNP values predict extubation failure in critically ill neonates with pulmonary hypertension and ventricular dysfunction

OBJECTIVES

Critically ill neonates with a history of pulmonary hypertension (PH) or ventricular dysfunction are at risk to experience an extubation failure (EF) after liberation from mechanical ventilation (MV). Due to insufficient data from neonatal cohorts, it remains unclear whether NT-proBNP is an appropriate biomarker to predict EF in this cohort. The Zlog-transformation of NT-proBNP (further named NT-proBNP_Zlog ) is an additional tool to optimize the interpretation of NT-proBNP since absolute NT-proBNP values are varying with the age of these infants.

PATIENTS AND METHODS

This was a retrospective single-center analysis at the University Children's Hospital, Bonn, Germany, during the study period from January 2020 until December 2021. Forty-three neonates met the inclusion criteria and were screened for study participation.

INCLUSION CRITERIA

prolonged (>24 h) MV with at least one extubation attempt, with a history of PH and/or ventricular dysfunction in the echocardiographic assessment at admission to the neonatal intensive care unit or during the period of MV, NT-proBNP measurements before (max. 24 h, baseline) and after (max. 24 h, follow-up) the first extubation attempt. The primary clinical endpoint was defined as EF with need for reintubation (0-72 h). Neonates with an EF were allocated to group A and neonates with successful liberation from MV to group B.

MAIN RESULTS

The primary clinical endpoint (EF) was reached in 21% (nine infants). Absolute mean NT-proBNP values (NT-proBNP_abs ) at baseline did not differ significantly in infants of group A and B (6931 vs. 7136 pg/ml, p = 0.227). NT-proBNP_Zlog values at baseline (2.35 vs. 1.57, p = 0.073) tended to higher values in group A. NT-proBNP_abs values measured at follow-up were significantly higher in infants allocated to group A (11120 vs. 7570 pg/ml, p = 0.027). Likewise, NT-proBNP_Zlog values at follow-up were significantly higher in infants allocated to group A (3.05 vs. 1.93, p = 0.009). NT-proBNP_abs values at follow-up and NT-proBNP_Zlog values at baseline correlated significantly with the severity of PH. Regarding the receiver operating characteristic-analysis, a NT-proBNP_abs value at follow-up of ≥4622 pg/ml was calculated as optimal cut-off value for the prediction of EF (area under the curve [AUC] 0.742, p = 0.001). A NT-proBNP_Zlog value at baseline of ≥1.63 and at follow-up of ≥2.14 was calculated as optimal cut-off for the prediction of EF (AUC: 0.690/p = 0.027, and 0.781/p = 0.000, respectively).

CONCLUSION

NT-proBNP_abs and NT-proBNP_Zlog might be valuable biomarkers for the prediction of EF in critically ill neonates. The Zlog-transformation of NT-proBNP allows an age-independent interpretation of NT-proBNP and should be considered for clinical routine.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

IMPACT

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

Development and Validation of a Nomogram for Predicting Bronchopulmonary Dysplasia in Very-Low-Birth-Weight Infants

Background: Bronchopulmonary dysplasia is a common pulmonary disease in newborns and is one of the main causes of death. The aim of this study was to build a new simple-to-use nomogram to screen high-risk populations. Methods: In this single-center retrospective study performed from January 2017 to December 2020, we reviewed data on very-low-birth-weight infants whose gestational ages were below 32 weeks. LASSO regression was used to select variables for the risk model. Then, we used multivariable logistic regression to build the prediction model incorporating these selected features. Discrimination was assessed by the C-index, and and calibration of the model was assessed by and calibration curve and the Hosmer-Lemeshow test. Results: The LASSO regression identified gestational age, duration of ventilation and serum NT-proBNP in the 1st week as significant predictors of BPD. The nomogram-illustrated model showed good discrimination and calibration. The C-index was 0.853 (95% CI: 0.851-0.854) in the training set and 0.855 (95% CI: 0.77-0.94) in the validation set. The calibration curve and Hosmer-Lemeshow test results showed good calibration between the predictions of the nomogram and the actual observations. Conclusion: We demonstrated a simple-to-use nomogram for predicting BPD in the early stage. It may help clinicians recognize high-risk populations.

Development of a Nomogram for Moderate-to-Severe Bronchopulmonary Dysplasia or Death: Role of N-Terminal Pro-brain Natriuretic Peptide as a Biomarker

Objectives: This study aimed to explore the clinical value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in predicting moderate-to-severe bronchopulmonary dysplasia (BPD)/death, and to establish an effective clinical predictive nomogram. Methods: We retrospectively analyzed very low birth weight infants (VLBWs) with gestational age ≤ 32 weeks. The NT-proBNP values were determined on the 1st, 3rd, 7th, 14th, 21st, and 28th days after birth. The correlation between NT-proBNP level and moderate-to-severe BPD/death was evaluated. Receiver operating characteristic (ROC) curve analysis was used to evaluate the prediction ability. Then, we used multivariable logistic regression to build the prediction model and nomogram, and calibration of the model was assessed by calibration curve. Results: In total, 556 VLBWs were involved, among whom 229 developed BPD (mild: n = 109; moderate: n = 68; severe: n = 52) and 18 died. The NT-proBNP level in the moderate-to-severe BPD/death group was significantly higher than that in the no-to-mild BPD group from the 3rd to 28th day (P < 0.001). When the natural logarithm of the serum NT-ProBNP level increased by 1 unit at day 7 (±2 days) of life, the risk of moderate and severe BPD/death was the highest (OR = 3.753; 95% CI: 2.984~4.720), and ROC analysis identified an optimal cutoff point of 3360 ng/L (sensitivity: 80.0%; specificity: 86.2%; AUC: 0.861). After adjusting for confounding factors, the level of NT-proBNP at day 7 (±2 days) of life still had important predictive value for the development of moderate-to-severe BPD/death, significantly improving the predictive ability of the model. Conclusion: The level of NT-proBNP at day 7 (±2 days) of life can be used as an early promising biomarker for VLBWs to develop moderate-to-severe BPD/death. We constructed an early predictive nomogram to help clinicians identify high-risk populations.

Association Between NT-proBNP and Prolonged Length of Stay in Hospital Among Preterm Infants Born at 28-31 Weeks' Gestation

OBJECTIVE

In the early life of preterm infants, the relationship between heart function and length of hospitalization is unclear. This study aims to examine the association between serum NT-proBNP level on the 7th day (NT-proBNP7) after birth and length of hospitalization among preterm infants.

METHODS

A retrospective cohort study was conducted. Patients included 709 preterm infants born at 28-31 weeks' gestational age (GA) admitted to the NICU of the First Affiliated Hospital of Zhengzhou University between December 20, 2016, to April 31, 2021. Main outcome: Late discharge (postmenstrual age at discharge was in the fourth quartile (highest) among infants born at the same GA). Exposure factor: NT-proBNP7.

RESULTS

We observed increased prevalence ratios for late discharge among the tertile of logarithm of NT-proBNP7 level (LnNT-proBNP7) which was positive. Compared with the lowest tertile, infants in the highest tertile of LnNT-proBNP7 had an 8.4-fold increased probability of late discharge, and the results were consistent for the subgroups. Next, a non-linear (S-shaped) relationship between LnNT-proBNP7 and late discharge was observed, whose turning points were 7.5 and 9. The effect sizes and the confidence intervals on the left of the first turning point, between two turning points and on the right of the second turning point, were 0.6 (95% CI, 0.2-1.6), 5.0 (95% CI, 2.4-10.6), and 1.1 (95% CI, 0.2-6.1), respectively. In addition, the prevalence of BPD, NEC, nosocomial infection, or any of them was highest in the group of LnNT-proBNP7 ≥ 9, lowest in the group of LnNT-proBNP7 < 7.5.

CONCLUSION

Higher NT-proBNP7 levels were associated with longer hospitalization. The relationship between LnNT-proBNP7 and late discharge was S-shaped. LnNT-proBNP7 was positively related with late discharge when LnNT-proBNP7 was between 7.5 and 9.

Brain natriuretic peptide to predict successful liberation from mechanical ventilation in critically ill patients: a systematic review and meta-analysis

BACKGROUND

Predicting successful liberation from mechanical ventilation (MV) in critically ill patients is challenging. Brain natriuretic peptide (BNP) has been proposed to help guide decision-making for readiness to liberate from MV following a spontaneous breathing trial (SBT).

METHODS

We performed a systematic review and meta-analysis of randomized and prospective observational studies that measured BNP levels at the time of SBT in patients receiving MV. The primary endpoint was successful liberation from MV (absence of reintubation or non-invasive ventilation at 48 h). Statistical analyses included bi-variate and Moses-Littenberg models and DerSimonian-Laird pooling of areas under ROC curve (AUROC).

RESULTS

A total of 731 articles were screened. Eighteen adult and 2 pediatric studies were fulfilled pre-specified eligibility. The measure of the relative variation of BNP during SBT (ΔBNP%) after exclusion of SBT failure by clinical criteria in adults yielded a sensitivity and specificity of 0.889 [0.831-0.929] and 0.828 [0.730-0.896] for successful liberation from MV, respectively, with a pooled AUROC of 0.92 [0.88-0.97]. The pooled AUROC for any method of analysis for absolute variation of BNP (ΔBNP), pre-SBT BNP, and post-SBT BNP were 0.89 [0.83-0.95], 0.77 [0.63-0.91], and 0.85 [0.80-0.90], respectively.

CONCLUSION

The relative change in BNP during a SBT has potential value as an incremental tool after successful SBT to predict successful liberation from MV in adults. There is insufficient data to support the use of BNP in children or as an alternate test to clinical indices of SBT, or the use of ΔBNP, BNP-pre, and BNP-post as an alternate or incremental test.

TRIAL REGISTRATION

PROSPERO CRD42018087474 (6 February 2018).

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

CONTEXT

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Early NT-proBNP levels as a screening tool for the detection of hemodynamically significant patent ductus arteriosus during the first week of life in very low birth weight infants

OBJECTIVE

To assess whether early NT-ProBNP can identify the need for echocardiographic assessment of hemodynamically significant patent ductus arteriosus (HsPDA) in preterm infants.

STUDY DESIGN

Prospective observational study of infants with a gestational age ≤32 weeks. Echocardiographic assessment and NT-proBNP measurement were performed at 48-96 h. ROC curves were generated to assess optimal cutoffs to detect HsPDA and predict the need for treatment.

RESULTS

Eighty-five patients were included. HsPDA was present in 28 infants (37.6%), and 22 (25.8%) received treatment. The optimal NT-proBNP cutoff for the detection of HsPDA was 5099 pg/mL (sensitivity 94%, specificity 82%, area under the curve 0.941, P < 0.001). Only 1 child with NT-proBNP levels <5099 pg/mL was ultimately treated for PDA. NT-proBNP screening could have avoided 45 of 85 routine echocardiograms (53%).

CONCLUSION

NT-proBNP screening at 48-96 h of life may identify preterm infants at low risk for HsPDA, improving PDA management.

Pediatric pulmonology year in review 2014: Part 2

To better meet the needs of our readership for updated perspectives on the rapidly expanding knowledge in our field, we here summarize the past year's publications in our major topic areas, as well as selected publications in these areas from the core clinical journal literature outside our own pages. This is Part 2 of a series and covers articles on neonatal lung disease, pulmonary physiology, and respiratory infection.