Acute kidney injury and pneumothorax are risk factors for mortality in persistent pulmonary hypertension of the newborn in Thai neonates

A Nomogram Prediction Model for Persistent Pulmonary Hypertension of the Newborn in Neonates Hospitalized for the First Time After Birth

OBJECTIVE

Persistent pulmonary hypertension of the newborn (PPHN) is one of the critical neonatal diseases associated with high morbidity and mortality. This study attempted to conduct a nomogram prediction model for performing early identification of PPHN and providing effective information for clinical practice.

METHODS

A total of 456 newborns who first admitted to the hospital after birth were included in the analysis, including 138 newborns with PPHN and 318 newborns without PPHN (as controls). The optimal predictive variables selection was performed based on LASSO (least absolute shrinkage and selection operator) regression and multivariate logistic regression. Using the selected variables, a nomogram prediction model was developed. To validate the model, the model was assessed using the receiver operating characteristic curve, calibration plot, and clinical impact curve.

RESULTS

Six predictors, namely, gestational age, neonatal respiratory distress syndrome, the levels of hemoglobin and creatine kinase-MB, gestational thyroid dysfunction, and Pa o2 , were identified by LASSO and multivariate logistic regression analysis from the original 30 variables studied. The constructed model, using these predictors, exhibited favorable predictive ability for PPHN, with an area under the receiver operating characteristic of 0.897 (sensitivity = 0.876, specificity = 0.785) in the training set and 0.871 (sensitivity = 0.902, specificity = 0.695) in the validation set, and was well calibrated, as indicated by the PHosmer-Lemeshow test values of 0.233 and 0.876 for the training and validation sets, respectively.

CONCLUSIONS

The model included gestational age, neonatal respiratory distress syndrome, the levels of hemoglobin and creatine kinase-MB, gestational thyroid dysfunction, and Pa o2 had good prediction performance for predicting PPHN among newborns first admitted to the hospital after birth.

Etiology, Diagnosis and Management of Persistent Pulmonary Hypertension of the Newborn in Resource-limited Settings

Persistent Pulmonary Hypertension of the Newborn (PPHN) is more common in Low and middle income countries (LMICs) due to high incidence of sepsis, perinatal asphyxia and meconium aspiration syndrome. Presence of hypoxic respiratory faillure and greater than 5% difference in preductal and post ductal saturation increases clinical sucipision for PPHN. The availability of Inhaled nitric oxide and extracorporaeal membrane oxygenation is limited but pulmonary vasodilators such as sildenafil are readily available in most LMICs.

A nomogram prediction model for early death in patients with persistent pulmonary hypertension of the newborn

Background

Persistent pulmonary hypertension of the newborn (PPHN) is a major lethal disorder in neonates that leads to an extremely high mortality rate. Thus, the early identification of adverse outcomes in PPHN is critical for clinical practice. This research attempted to develop a nomogram prediction system for assessing the mortality of newborns with PPHN.

Methods

Two hundred and three newborns with PPHN diagnosed from January 2015 to March 2022 were involved in the study. The clinical features of these newborns and pregnancy details were compared between newborns in the survival and lethal groups. Univariable and multivariate analyses were established in sequence to demonstrate the essential risk factors. The nomogram prediction model was built.

Results

A total of 203 newborns were included in the analysis. 136 (67.0%) newborns represented the hospital survival group. Plasma pH value (OR = 0.606, p = 0.000, 95% CI 0.45715-0.80315), septicemia (OR = 3.544, p = 0.000, 95% CI 1.85160-6.78300), and abnormal pregnancy history (OR = 3.331, p = 0.008, 95% CI 1.37550-8.06680) were identified as independent risk factors for neonatal death in newborns associated with PPHN. Finally, the nomogram predictive model was established based on multivariate analysis results, indicating the efficacies of prediction and calibration.

Conclusion

This study generated an applicable risk score formula using the plasma pH value, septicemia, and abnormal pregnancy history to recognize neonatal death in newborns with PPHN, presenting a sufficient predictive value and calibration.

Possible association between a polymorphism of EPAS1 gene and persistent pulmonary hypertension of the newborn: a case-control study

OBJECTIVE

To explore possible genes related to the development of persistent pulmonary hypertension of the newborn (PPHN).

METHODS

The authors identified 285 single nucleotide polymorphisms (SNPs) of 11 candidate genes (BMPR2, EPAS1, PDE3A, VEGFA, ENG, NOTCH3, SOD3, CPS1, ABCA3, ACVRL1, and SMAD9), using an Illumina Asian Screening Array-24 v1.0 BeadChip Array. The FastLmmC and R package was used for statistical analyses. The chi-square test and Cochrane-Armitage trend test were used to compare the allele and genotype frequencies between the groups and to test the genetic models, respectively.

RESULTS

A total of 45 PPHN infants and 294 control subjects were analyzed. The most common cause of PPHN was meconium aspiration syndrome. Among the 285 SNPs, 17 SNPs from 6 candidate genes (BMPR2, EPAS1, PDE3A, VEGFA, ENG, and NOTCH3) were significantly associated with PPHN (P < 0.05). After using the Bonferroni correction (P < 0.00018), only the rs17034984 SNP located in intron 1 of the EPAS1 gene remained significantly different between the PPHN and control subjects (P = 0.00014). The frequency of the TC/TT genotype of rs17034984 in the gene with the dominant model was significant in the patients with PPHN (OR = 5.38, 95% CI: 2.15-13.49). The T allele frequency of rs17034984 in the gene showed a significant difference compared with the control subjects (OR = 4.89, 95% CI: 2.03-11.82).

CONCLUSIONS

The present study suggests that the rs17034984 variant of EPAS1 gene is associated with PPHN.

Risk Factors and Outcomes of Acute Kidney Injury in Neonates with Persistent Pulmonary Hypertension of the Newborn

Objective

To identify the incidence of and risk factors for acute kidney injury (AKI) in neonates with persistent pulmonary hypertension of the newborn (PPHN) and to evaluate its association with neonatal outcomes.

Method

A total of 78 newborns with confirmed PPHN admitted to the neonatal intensive care unit of a university hospital between 2016 and 2020 were retrospectively analyzed. AKI was defined according to the modified neonatal Kidney Disease: Improving Global Outcomes criteria.

Results

Of 78 PPHN infants, AKI was found in 29.5% (23/78). Multivariate analysis indicated that male sex (OR 3.43 95% CI 1.03-11.48, p=0.04) and severe PPHN (OR 5.67 95% CI 1.55-20.68, p<0.01) were independently associated with increased risk for AKI. Infants with AKI had significantly higher mortality rate than infants without AKI (43.5% vs. 9.1%, p<0.01). Mortality rates in stage 1, stage 2 and stage 3 AKI were similar (36.4%, 57.1%, and 40%, respectively, p=0.68). Among survivors, AKI infants had significantly longer mechanical ventilation and lenght of stay than infants without AKI.

Conclusion

In infants with PPHN, AKI is a common complication and is associated with increased mortality, and longer mechanical ventilation and lenght of stay. Careful monitoring of kidney function in infants with PPHN, especially in males and those who had severe PPHN can help to improve patient outcomes.

Postnatal causes and severity of persistent pulmonary Hypertension of Newborn

Background & Objective:

Persistent pulmonary hypertension of the newborn (PPHN) is described as severe respiratory failure along with hypoxaemia. PPHN is known to be linked with high morbidity and mortality around the world. This study was planned to determine the postnatal causes and assess the severity of persistent pulmonary hypertension of newborn in babies presenting to the Children’s Hospital, Multan.

Methods:

This observational study was conducted at the Department of Paediatric Cardiology, The Children Hospital &Institute of Child Health, Multan, Pakistan from July to December 2019. A total of 122 confirmed cases of PPHN admitted having gestational age above 34 weeks were enrolled. Demographic data of the newborns was recorded along with maternal medical history, pregnancy status and postnatal causes of PPHN. Severity of PPHN was also recorded.

Results:

Out of a total of 122 cases of PPHN, 81 (66.3%) were male. Majority, 78 (64.0%) had gestational age above 37 weeks. Mode of delivery as cesarean section was noted in 70 (57.4%). Meconium aspiration syndrome 52 (42.6%), birth asphyxia 48 (39.3%), respiratory distress syndrome 23 (18.8%) and sepsis 33 (27.0%) were found to be the commonest causes of PPHN. Severe PPHN was found to be the most frequent, noted among 63 (51.6%) while Moderate PPHN was observed in 40 (32.8%) and Mild PPHN in 19 (15.6%). Morality was noted among 26 (21.3%) of cases.

Conclusion:

Meconium aspiration syndrome, birth asphyxia and respiratory distress syndrome were the commonest postnatal causes of PPHN. Severe PPHN was found to be the most frequent form of PPHN.

Survival and associated risk factors for mortality among infants with persistent pulmonary hypertension of the newborn in Malaysia

OBJECTIVE

This study aims to determine the immediate outcome of persistent pulmonary hypertension of the newborn (PPHN) and risk factors for mortality in the era of inhaled nitric oxide (iNO).

STUDY DESIGN

This observational cross-sectional study includes 195 confirmed PPHN with a gestational age of ≥34 weeks without congenital heart disease. Multivariable logistic regression was used to identify risk factors for mortality.

RESULTS

The mortality rate was 16.4%, with the highest mortality with pulmonary hypoplasia. Of 195, 65% received iNO; 18% were iNO non-responders with the majority having pulmonary hypoplasia. Independent risk factors for mortality were the presence of reversal of flow at the descending aorta, pulmonary hypoplasia, APGAR scores ≤ 5 at 5 min, and idiopathic PPHN with an adjusted odds ratio of 15.9, 7.5, 6.7, and 6.4, respectively.

CONCLUSIONS

Despite the usage of iNO, mortality due to PPHN remains high and is related to etiology and cardiac function.

Risk factor analysis of pneumothorax associated with persistent pulmonary hypertension of the newborn in Thai neonates

Objective: To determine the risk factors and outcomes of persistent pulmonary hypertension of the newborn (PPHN)-associated pneumothorax (PTX).Study design: The medical records of infants diagnosed with PPHN with or without PTX from January 2012 to July 2017 were retrospectively reviewed.Results: Of the 102 included PPHN infants, PTX was found in 32 (31.4%) infants with 43.8% (14/32) mortality. PTX was significantly associated with increased mortality with an odds ratio (OR) of 5.27 (95% confidence interval [CI] 1.96-14.17). Unilateral PTX was more common than bilateral PTX (53.1 versus 46.9%, respectively). Multivariate logistic regression analysis indicated that a 1-minute Apgar score of ≤7 was associated with an increased risk for PTX (adjusted OR = 2.67 [95% CI 1.14-6.25]). In subgroup analysis, each increase of maximum peak inspiratory pressure (PIP) of 1 cmH₂O significantly increased the odds of PTX by 1.46 (95% CI 1.02-2.07), while each 1 mmHg increase in arterial partial pressure of oxygen (P_aO₂) decreased the odds of PTX (adjusted OR = by 0.98 [95% CI 0.97-0.99]).Conclusions: PTX was significantly associated with higher mortality in PPHN infants. Lower Apgar score and increasing PIP in conventional mechanical ventilation were risk factors for PTX. Higher P_aO₂ was associated with a decreased rate of PTX.

An Asian multicenter retrospective study on persistent pulmonary hypertension of the newborn: incidence, etiology, diagnosis, treatment and outcome

Objectives: To explore the incidence, etiologies, diagnostic methods, treatment options and outcomes in neonates with persistent pulmonary hypertension of the newborn (PPHN) and to identify mortality risk factors in a study from six Asian countries.Methods: A retrospective chart review of patients with documented PPHN from seven centers in six Asian countries (Japan, Kuwait, India, Pakistan, Singapore, and Thailand) between 1 January, 2014 and 31 December, 2016, was performed.Results: A total of 369 PPHN infants were identified. The incidence of PPHN ranged from 1.2 to 4.6 per 1000 live births. The all-cause mortality rate was 20.6% (76 of 369). Meconium aspiration syndrome was the primary cause of PPHN (24.1%). In most cases (84.8%) echocardiography was used to establish the diagnosis of PPHN. Sildenafil was the most commonly used pulmonary vasodilator (51.2%). Multivariate multiple regression analysis indicated gestational age <34 weeks (adjusted odds ratio (OR) = 3.27; 95% CI 1.56-6.74), congenital diaphragmatic hernia (CDH)/lung hypoplasia (LH) (adjusted OR = 6.13 (95% CI 2.28-16.42)), treatment with high frequency oscillation ventilation (HFOV) with or without inhaled nitric oxide (iNO) (adjusted OR = 3.11 (95% CI 1.52-6.34)), and inotropic agents (adjusted OR = 9.43 (95% CI 2.71-32.83)) were independently associated with increased risk of death.Conclusions: The incidence of PPHN in the current study was higher than in western settings. Birth weight, gestational age, CDH/LH, HFOV/iNO, and inotropic agents were significant mortality risk factors.

Polymorphisms in urea cycle enzyme genes are associated with persistent pulmonary hypertension of the newborn

BackgroundPersistent pulmonary hypertension of the newborn (PPHN) is characterized by elevated pulmonary vascular resistance. Endogenous nitric oxide is critical for regulation of pulmonary vascular resistance. Nitric oxide is generated from L-arginine, supplied by the urea cycle (UC). We hypothesized that polymorphisms in UC enzyme genes and low concentrations of UC intermediates are associated with PPHN.MethodsWe performed a family-based candidate gene analysis to study 48 single-nucleotide polymorphisms (SNPs) in six UC enzyme genes. Genotyping was carried out in 94 infants with PPHN and their parents. We also performed a case-control analysis of 32 cases with PPHN and 64 controls to identify an association between amino-acid levels on initial newborn screening and PPHN.ResultsThree SNPs (rs41272673, rs4399666, and rs2287599) in carbamoyl phosphate synthase 1 gene (CPS1) showed a significant association with PPHN (P=0.02). Tyrosine levels were significantly lower (P=0.003) and phenylalanine levels were significantly higher (P=0.01) in cases with PPHN. There was no difference in the arginine or citrulline levels between the two groups.ConclusionsThis study suggests an association (P<0.05) between SNPs in CPS1 and PPHN. These findings warrant further replication in larger cohorts of patients.

Fatal Vernix Caseosa Aspiration Associated With Persistent Pulmonary Hypertension of the Newborn

Vernix caseosa aspiration is an extremely rare condition resulting in high mortality if complicated by persistent hypertension of the newborn (PPHN). Herein we offer the first case report of PPHN due to massive vernix caseosa aspiration documented by histopathological examination. This case report is presented to provide a synopsis of the pathoetiology of PPHN related to vernix caseosa aspiration syndrome as likely to be encountered by neonatologists and general pediatricians involved with neonatal care.

An international survey on persistent pulmonary hypertension of the newborn: A need for an evidence-based management

OBJECTIVE

To assess the current practice preferences in diagnosis and management of persistent hypertension of the newborn (PPHN) of neonatologists or pediatricians with expertise in neonatal care.

STUDY DESIGN

Investigators identified potential participants worldwide through a literature search. They were emailed the URL of an online 25-item questionnaire through the web survey site SurveyMonkey®. Additional respondents were also acquired through a professional online discussion group. The survey was conducted during July - September 2015.

RESULTS

Overall, there were 200 respondents from 51 different countries. Of these, the average 2014 mortality rate of the 90 respondents who completed this section of the questionnaire was 8.3% (interquartile range (IQR): 0-20.3). Echocardiography together with pre-to-post ductal oxygen pulse oximetry (SpO2) gradient was the most common PPHN diagnostic method. The most frequent first-line pulmonary vasodilator was inhaled nitric oxide (155/199, 77.9%). Oral sildenafil was most commonly used as second-line adjunctive therapy by 46.3% (81/175). Dopamine (139/198, 70.2%) was chosen to be the initial inotropic agent and normal saline (191/199, 96.0%) was the preferred initial fluid resuscitation for hypotension. Sedation and analgesia were routinely used for PPHN treatment. Twenty-one percent (42/199) of respondents also used muscle relaxants to control respiratory distress. The most commonly used targets for partial pressure of oxygen, partial pressure of carbon dioxide, SpO2 and hemoglobin were 71-80 mmHg (60/197, 30.4%), 36-45 mmHg (100/199, 50.2%), 91-95% (111/199, 55.8%), and 13-15 gm/dL (156/196, 79.6%), respectively.

CONCLUSIONS

This survey shows that the management of PPHN varies widely around the world. The major PPHN diagnostic method is echocardiography together with bedside SpO2 monitoring. The study numbers show the main differences are between developed and developing countries. Further studies exploring evidence-based principles of diagnosis and management in PPHN are warranted.