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

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.

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.

Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) in the neonatal intensive care unit (NICU): an Australian NICU experience

BACKGROUND

Preterm infants often require non-invasive breathing support while their lungs and control of respiration are still developing. Non-invasive neurally adjusted ventilatory assist (NIV-NAVA) is an emerging technology that allows infants to breathe spontaneously while receiving support breaths proportional to their effort. This study describes the first Australian Neonatal Intensive Care Unit (NICU) experience of NIV-NAVA.

METHODS

Retrospective cohort study of infants admitted to a major tertiary NICU between October 2017 and April 2021 supported with NIV-NAVA. Infants were divided into three groups based on the indication to initiate NIV-NAVA (post-extubation; apnoea; escalation). Successful application of NIV-NAVA was based on the need for re-intubation within 48 h of application.

RESULTS

There were 169 NIV-NAVA episodes in 122 infants (82 post-extubation; 21 apnoea; 66 escalation). The median (range) gestational age at birth was 25 + 5 weeks (23 + 1 to 43 + 3 weeks) and median (range) birthweight was 963 g (365-4320 g). At NIV-NAVA application, mean (SD) age was 17 days (18.2), and median (range) weight was 850 g (501-4310 g). Infants did not require intubation within 48 h in 145/169 (85.2%) episodes [72/82 (87.8%) extubation; 21/21 (100%) apnoea; 52/66 (78.8%) escalation).

CONCLUSION

NIV-NAVA was successfully integrated for the three main indications (escalation; post-extubation; apnoea). Prospective clinical trials are still required to establish its effectiveness versus other modes of non-invasive support.

Respiratory Severity Score during the First 3 Hours of Life as a Predictor for Failure of Noninvasive Respiratory Support and Need for Late Rescue Surfactant Administration

OBJECTIVE

Preterm infants often develop failure of noninvasive respiratory support. These infants miss the advantages of early rescue surfactant therapy. In this study, we evaluate the utility of respiratory severity score (RSS) during the first 3 hours of life (HOL) as a predictor for failure of noninvasive respiratory support.

STUDY DESIGN

We conducted a post hoc analysis of infants between 23 and 40 weeks' gestational age who received usual care in the AERO-02 clinical trial. Univariate and multivariable logistic regression analysis were used to assess whether the RSS summary measures were associated with the odds of surfactant administration.

RESULTS

Study involved 146 infants. Sixty-four infants (45%) received surfactant within the first 72 hours. Administration of surfactant was associated with the mean RSS (p < 0.01) and the linear trend (p < 0.01).

CONCLUSION

We demonstrated that RSS during the first 3 HOL can predict failure of noninvasive respiratory support and need for late rescue surfactant administration. Optimal RSS cutoffs for early rescue surfactant therapy need to be determined in large cohort studies.

KEY POINTS

· Early recognition of infants at risk of failure of noninvasive ventilation is important to prevent complications.. · It is desirable to identify patients who would benefit from early rescue surfactant treatment.. · RSS in first 3 hours can be used as a predictor of failure of noninvasive respiratory support..

Risk Prediction of Severe Bronchopulmonary Dysplasia (BPD) Using the Respiratory Severity Score (RSS) in Extremely Preterm Infants: A Retrospective Study From Saudi Arabia

Background Bronchopulmonary dysplasia (BPD) is a significant complication in extremely preterm infants. Therefore, early diagnosis of BPD is important for planning treatment strategies. In this study, we aimed to assess the predictive efficacy of the Respiratory Severity Score (RSS) in determining severe BPD or death outcomes in very preterm infants. Methodology This retrospective study included preterm infants born with a gestational age of ≤30 weeks. The inclusion criteria comprised individuals who were mechanically ventilated (<1 week) during the first four weeks of life. Any patients who died during the first seven days of life were excluded. RSS values were recorded on days 3, 14, 21, and 28 of life. Multivariate logistic regression was used to identify a correlation between RSS and patient outcomes. Results A total of 154 infants were included in the analysis, of whom 82 (53.24%) developed severe BPD and 38 (24.67%) died. RSS was higher in patients who either died or developed severe BPD compared to those who survived. The multivariate logistic regression analysis revealed that RSSs at postnatal day 14 (odds ratio (OR) = 3.970; 95% confidence interval (CI) = 1.114-14.147; p < 0.05), day 21 (OR = 6.201; 95% CI = 1.937-19.851; p < 0.05), and day 28 (OR = 8.925; 95% CI = 3.331-28.383; p < 0.05) was significantly associated with a higher risk of death or severe BPD. Conclusions The findings of the present study revealed that RSS can help predict the risk of severe BPD in very preterm infants.

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.

Evaluation of levosimendan as treatment option in a large case-series of preterm infants with cardiac dysfunction and pulmonary hypertension

Levosimendan as a calcium-sensitizer is a promising innovative therapeutical option for the treatment of severe cardiac dysfunction (CD) and pulmonary hypertension (PH) in preterm infants, but no data are available analyzing levosimendan in cohorts of preterm infants. The design/setting of the evaluation is in a large case-series of preterm infants with CD and PH. Data of all preterm infants (gestational age (GA) < 37 weeks) with levosimendan treatment and CD and/or PH in the echocardiographic assessment between 01/2018 and 06/2021 were screened for analysis. The primary clinical endpoint was defined as echocardiographic response to levosimendan. Preterm infants (105) were finally enrolled for further analysis. The preterm infants (48%) were classified as extremely low GA newborns (ELGANs, < 28 weeks of GA) and 73% as very low birth weight infants (< 1500 g, VLBW). The primary endpoint was reached in 71%, without difference regarding GA or BW. The incidence of moderate or severe PH decreased from baseline to follow-up (24 h) in about 30%, with a significant decrease in the responder group (p < 0.001). The incidence of left ventricular dysfunction and bi-ventricular dysfunction decreased significantly from baseline to follow-up (24 h) in the responder-group (p = 0.007, and p < 0.001, respectively). The arterial lactate level decreased significantly from baseline (4.7 mmol/l) to 12 h (3.6 mmol/l, p < 0.05), and 24 h (3.1 mmol/l, p < 0.01).  Conclusion: Levosimendan treatment is associated with an improvement of both CD and PH in preterm infants, with a stabilization of the mean arterial pressure during the treatment and a significant decrease of arterial lactate levels. Future prospective trials are highly warranted. What is Known: • Levosimendan as a calcium-sensitizer and inodilator is known to improve the low cardiac output syndrome (LCOS), and improves ventricular dysfunction, and PH, both in pediatric as well as in adult populations. Data related to critically ill neonates without major cardiac surgery and preterm infants are not available. What is New: • This study evaluated the effect of levosimendan on hemodynamics, clinical scores, echocardiographic severity parameters, and arterial lactate levels in a case-series of 105 preterm infants for the first time. Levosimendan treatment in preterm infants is associated with a rapid improvement of CD and PH, an increase of the mean arterial pressure, and a significant decrease in arterial lactate levels, as surrogate marker for a LCOS. • How this study might affect research, practice, or policy. As no data are available regarding the use of levosimendan in this population, our results hopefully animate the research community to conduct future prospective trails analyzing levosimendan in randomized controlled trials (RCT) and observational control studies. Additionally, our results potentially motivate clinicians to introduce levosimendan as second second-line therapy in cases of severe CD and PH in preterm infants without improvement using standard treatment strategies.

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%.

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.

Risk factors and clinical outcomes of extubation failure in very early preterm infants: a single-center cohort study

BACKGROUND

Early extubation success (ES) in preterm infants may reduce various mechanical ventilation-associated complications; however, extubation failure (EF) can cause adverse short- and long-term outcomes. Therefore, the present study aimed to identify differences in risk factors and clinical outcomes between ES and EF in very early preterm infants.

METHODS

This retrospective study was conducted between January 2017 and December 2021. Premature infants born at 32 weeks' gestational age in whom extubation had failed at least once were assigned to the EF group. Successfully extubated patients with a similar gestational age and birth weight as those in the EF group were assigned to the ES group. EF was defined as the need for re-intubation within 120 h of extubation. Various variables were compared between groups.

RESULTS

The EF rate in this study was 18.6% (24/129), and approximately 80% of patients with EF required re-intubation within 90.17 h. In the ES group, there was less use of inotropes within 7 days of life (12 [63.2%] vs. 22 [91.7%], p = 0.022), a lower respiratory severity score (RSS) at 1 and 4 weeks (1.72 vs. 2.5, p = 0.026; 1.73 vs. 2.92, p = 0.010), and a faster time to reach full feeding (18.7 vs. 29.7, p = 0.020). There was a higher severity of bronchopulmonary dysplasia BPD (3 [15.8%] vs. 14 [58.3%], p = 0.018), longer duration of oxygen supply (66.5 vs. 92.9, p = 0.042), and higher corrected age at discharge (39.6 vs. 42.5, p = 0.043) in the EF group. The cutoff value, sensitivity, and specificity of the respiratory severity score (RSS) at 1 week were 1.98, 0.71, and 0.42, respectively, and the cutoff value, sensitivity, and specificity of RSS at 4 weeks were 2.22, 0.67, and 0.47, respectively.

CONCLUSIONS

EF caused adverse short-term outcomes such as a higher BPD severity and longer hospital stay. Therefore, extubation in very early preterm infants should be carefully evaluated. Using inotropes, feeding, and RSS at 1 week of age can help predict extubation success.

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.

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.

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.

Evaluation of Short-term Outcomes of Tracheostomy Procedures in a NICU Population With High Ventilator Settings

OBJECTIVE

To investigate whether tracheostomy placement in infants requiring high ventilator pressure is safe and effective.

STUDY DESIGN

Case series with chart review.

SETTING

Tertiary children's hospital.

METHODS

Fifty ventilator-dependent neonatal intensive care unit patients who underwent tracheotomy from 2009 to 2018 were included. Patients requiring high ventilator pressures were compared to those requiring low ventilator pressures. Demographics, comorbidities, and surgical and clinical data were recorded.

RESULTS

Thirty-two percent (n = 16) had low ventilator settings at the time of tracheostomy tube placement, and 68% (n = 34) had high ventilator settings. The median peak inspiratory pressure of the high ventilator group was 29.5 cm H₂O, positive end-expiratory pressure (PEEP) was 8 cm H₂O, mean airway pressure was 13 cm H₂O, pressure support (PS) was 14 cm H₂O, PS above PEEP was 6 cm H₂O, and inspiratory time was 0.65 seconds. The high ventilator cohort had a higher median age at the time of surgery compared to the low ventilator group (P = .02). Female patients were more likely to have high ventilator settings (P = .02). There were no intraoperative complications or deaths within the first 7 days of tracheostomy tube placement. Pneumonia incidence and rate of mortality during admission did not vary by ventilator settings (P = .92 and P = .94, respectively).

CONCLUSION

Few differences in tracheostomy tube placement outcomes were observed for patients with high ventilator settings compared to low ventilator settings. These data demonstrate that patients requiring high ventilator pressures can benefit from tracheostomy tube placement with no additional short-term risks.

Saturation oxygenation pressure index: a non-invasive bedside measure for severity of respiratory disease in neonates on CPAP

The treatment of respiratory distress in neonates ranges from non-invasive continuous positive airway pressure (CPAP) to advanced invasive mechanical ventilation. Monitoring on CPAP is often done by calculating oxygenation after blood gas analysis which is an invasive procedure. Saturation oxygen pressure index (SOPI) is a simple, non-invasive, bedside tool to monitor the severity of respiratory illness in neonates on CPAP. This study was aimed at validation of SOP index against AaDO2 and determine the cut-off values of SOPI for A-aDO2 of 70, 85 and100. This was a prospective observational study on 126 neonates with respiratory distress and treated with CPAP. The correlation between SOPI and A-aDO2 was validated using Bootstrap method. There was a significant positive correlation between SOPI and A-aDO2 with the Spearman correlation coefficient (rho) being 0.815 (p = 0). The mean coefficient of correlation after Bootstrap was 0.827 (p value < 0.0001). SOPI values of 1.52, 1.57 and 1.6 predicted A-aDO2 value of 70, 85 and 100 with a sensitivity of above 80% and specificity above 90%, respectively.Conclusion: SOPI has a significant positive correlation of 82.7% against A-aDO2 and can be a valuable tool to assess respiratory distress in neonates without arterial blood gas. What is Known: • Saturation oxygen pressure index (SOPI) is a non-invasive monitoring tool for neonates on N-CPAP. • SOPI has a good correlation with AaDO2. What is New: • Correlation of SOPI with AaDO2 is now validated. • Values between 1.52 and 1.88 indicate clinically useful range of AaDO2 for escalation of respiratory support from CPAP.

Predicting outcomes of mechanically ventilated premature infants using respiratory severity score

BACKGROUND

Extremely low birth weight (ELBW) infants have significant morbidities and higher mortality. The major morbidities are bronchopulmonary dysplasia (BPD), intraventricular hemorrhage (IVH) and retinopathy of prematurity (ROP). Release of proinflammatory cytokines has been implicated in the development of systemic inflammation that contributes to BPD aND ROP. Also, cumulative oxygen exposure in the first 3 days of life and use of mechanical ventilation was associated with 3-fold increase in severe IVH. Therefore, early ventilation and oxygenation may contribute significantly to morbidities in ELBW infants. Respiratory severity score (RSS), a product of Mean airway pressure (MAP) and FiO2, is a steady-state noninvasive assessment tool useful in infants to monitor the severity of respiratory failure. We used RSS, in the first 3 days of life of ELBW infants, to predict neonatal morbidities and mortality.

STUDY DESIGN

In a single-center retrospective cohort study in an urban setting, convenience sampling of ELBW infants meeting the study criteria who were mechanically ventilated at birth for the first 3 days of life were included. Time-weighted average RSS was plotted on receiver-operating characteristic (ROC) curve in the first 3 days of life to predict outcomes. Sensitivity, specificity, positive predictive value, negative predictive value and likelihood ratios were calculated.

RESULTS

A total of 69 infants qualified for the study. RSS in the first 3 days significantly predicted the composite outcome of death, ROP, IVH or BPD with an area under the curve (AUC) of 0.82 (p < 0.001). Individually, RSS predicted death, severe ROP and IVH with an AUC of 0.86, 0.77 and 0.71 respectively; but did not predict severe BPD (AUC 0.61). RSS was more sensitive and specific than each of its component; FiO₂ and MAP. Weighted RSS in the first 3 days had high-negative predictive value of 98.1% for death between 7 days and 36 weeks, 94.6% for ROP and 91.7% for IVH.

CONCLUSIONS

This study is the first to show that RSS in the first 3 days of life is a good predictor of composite neonatal outcomes: severe IVH, BPD, ROP, or mortality. Early RSS had a high positive predictive value for the composite outcome of morbidities/mortality and a high specificity for mortality, ROP, and IVH individually.

Respiratory Severity Score greater than or equal to 2 at birth is associated with an increased risk of mortality in infants with birth weights less than or equal to 1250 g

OBJECTIVE

Respiratory Severity Score (RSS), the product of mean airway pressure and the fraction of inspired oxygen may estimate the severity of neonatal lung disease. We aimed to determine if RSS on the first day of life is associated with mortality and/or comorbidities in infants born less than or equal to 1250 g.

METHODS

Data were extracted from the NYS Perinatal Data System for premature inborn infants from 2006 to 2016 born between 400 and 1250 g (N = 730). RSS was divided into three categories: less than 2 (low, n = 310), 2-5 (moderate, n = 265), greater than 5 (high, n = 155). The primary outcome was mortality. Logistic regression determined associations with composite outcomes of death or respiratory morbidity (respiratory support after 36 weeks postmenstrual age), death or neurologic morbidity (periventricular leukomalacia) or high-grade intraventricular hemorrhage), and death/severe morbidity (death or neurologic morbidity or respiratory morbidity or stage ≥ III retinopathy of prematurity or necrotizing enterocolitis) by RSS category.

RESULTS

Birthweight and gestational age were lower with the increasing RSS category (p < .001 for both). Mode of delivery, antenatal steroids, and maternal age did not differ by RSS. In adjusted analyses, there were increased odds of mortality in infants with moderate RSS (odds ratio [95% confidence intervals]: 3.1 (1.7-5.4) and high 4.5 (2.5-8.2). These groups had higher odds of death or respiratory morbidity, death or neurologic morbidity, and death/severe morbidity.

CONCLUSION

Higher RSS (≥2) is associated with an increased risk of mortality and morbidities in infants born less than or equal to 1250 g.

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

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

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical and echocardiographic risk factors for extubation failure in infants with congenital diaphragmatic hernia

INTRODUCTION

Infants after surgical correction of congenital diaphragmatic hernia are at high risk for extubation failure, but little is known about contributing factors. Therefore, our study aimed to analyze clinical and echocardiographic parameters.

MATERIALS AND METHODS

Data of 34 infants with congenital diaphragmatic hernia treated at our department (July 2013-December 2015) were analyzed. Inclusion criteria were: presence of congenital diaphragmatic hernia and echocardiography performed within 48 hours before the first, and, in case of reintubation, the final extubation attempt. Infants were allocated to group A (extubation failure) and group B (extubation successful).

RESULTS

Extubation failure occurred in 12/34 infants (35%). Infants in group A had a higher proportion of intrathoracic liver herniation (P = 0.001, OR 17 [2.8/104.5]) and lower rates of the lung-to-head ratio (P = 0.042, 95% CI [-0.4/20]), even as higher rates of extracorporeal membrane oxygenation (P = 0.001, 95% CI [2.7/80.9]). The oxygenation index and the PaO₂ /FiO₂ ratio differed significantly between both groups (both P = 0.000; 95% CI [-11/-4.1] and [79/215], respectively). The mean airway pressure and fraction of inspired oxygen prior to extubation was significantly higher in group A (P = 0.008; 95% CI [-3.9/-1.4]; P = 0.000; 95% CI [-0.6/-0.2], respectively). In addition, the respiratory severity score was higher in group A (P = 0.000; 95% CI [-7.3/-2.6]). In group A, administration of sildenafil and the vasoactive inotropic score were significantly higher (P = 0.037; OR 9 [0.9/88.6] and P = 0.013; 95% CI [-14/-1.8], respectively). More infants in group A had need for a surgical patch repair of the diaphragm (P = 0.017; OR 7.2 [1.3/41.1]) and showed higher rates of relevant pleural effusions prior the extubation (P = 0.021; OR 6 [1.2/29.5]). The total duration of the ventilation and the length of hospital stay were longer in group A (P = 0.004; 95% CI [-915/-190] and P = 0.000; 95% CI [-110/-39], respectively). The prevalence of pulmonary hypertension was more frequent in group A (P = 0.012; OR 12 [1.3/114]), the time to peak velocity in the main pulmonary artery was significantly lower in group A (P = 0.024; 95% CI [2/25.6]), and these infants suffered more often from cardiac dysfunction (P = 0.007; OR 10 [1.6/63.1]).

CONCLUSION

Our results demonstrate that extubation failure in infants with a congenital diaphragmatic hernia is associated with several clinical and echocardiographic risk factors.

Neonatal respiratory outcomes in pregnancy induced hypertension: introducing a novel index

Objective: To evaluate short-term respiratory outcomes, mortality and bronchopulmonary dysplasia (BPD) in preterm infants born to mothers with and without pregnancy induced hypertension (PIH).Methods: Exposed infants <33 weeks' gestation were matched to controls in a 1:2 ratio, based on gestation, sex and antenatal steroid exposure in this retrospective cohort study. Primary outcomes were a novel cumulative respiratory index (cRI) (product of mean airway pressure-hours and FiO₂-hours while on invasive ventilation during first 72 hours), mortality and BPD.Results: Seventy-nine exposed infants were matched with 158 controls. cRI was higher in exposed infants (median 1854; IQR 186-13,901) versus controls (median 1359; IQR 210-11,302) but not statistically significant (p = .63). On conditional regression analysis, PIH did not predict cRI (adjusted β = 0.96; 95% CI = 0.79-1.17; p = .712). No association between PIH and mortality (unadjusted odds ratio [OR] = 3.14; 95% CI = 0.76-13.0; p=.11) was identified. PIH was significantly associated with BPD on univariate analysis (OR = 2.29; 95% CI = 1.02-5.17; p=.046), but not after adjustment (aOR = 1.26; 95% CI = 0.38-4.19; p=.7).Conclusions: PIH was not associated with cRI, mortality or BPD in this study. Further validation of cRI and exploration of its relationship with PIH as well as neonatal outcomes is warranted.