Left atrial strain assessment unveils left ventricular diastolic dysfunction in neonates with transient tachypnea of the newborn: A prospective observational study.

INTRODUCTION: An inadequate clearance of lung fluid plays a key role in the pathogenesis of transient tachypnea of the newborn (TTN). OBJECTIVES: To evaluate if left ventricular diastolic dysfunction contributes to reduced clearance of lung fluid in TTN. MATERIALS AND METHODS: This was a prospective, observational study. Echocardiography and lung ultrasound were performed at 2, 24 and 48 h of life (HoL) to assess biventricular function and calculate lung ultrasound score (LUS). Left atrial strain reservoir (LASr) provided surrogate measurement of left ventricular diastolic function. RESULTS: Twenty-seven neonates with TTN were compared with 27 controls with no difference in gestation (36.1 ± 2 vs. 36.9 ± 2 weeks) or birthweight (2508 ± 667 vs. 2718 ± 590 g). Biventricular systolic function was normal in both groups. LASr was significantly lower in cases at 2 (21.0 ± 2.7 vs. 38.1 ± 4.4; p < 0.01), 24 (25.2 ± 4.5 vs. 40.6 ± 4.0; p < 0.01) and 48 HoL (36.5 ± 5.8 and 41.6 ± 5.2; p < 0.01), resulting in a significant group by time interaction (p < 0.001), after adjusting for LUS and gestational diabetes. A logistic regression model including LUS, birth weight and gestational diabetes as covariates, showed that LASr at 2 HoL was a predictor of respiratory support at 24 HoL, with an adjusted odds ratio of 0.60 (CI 0.36-0.99). CONCLUSIONS: LASr was reduced in neonates with TTN, suggesting diastolic dysfunction, that may contribute to the delay in lung fluid clearance.

Neonatal respiratory complications in twins at 36-38 weeks of gestation.

BACKGROUND: Twin pregnancies are associated with a high risk of perinatal mortality and morbidity. Late preterm or early term delivery is frequently performed to avoid unexpected fetal death in uncomplicated twin pregnancies. Nonetheless, delivery before full term is associated with neonatal respiratory complications. This study aimed to evaluate perinatal respiratory complications in twins delivered between 36 and 38 weeks of gestation. METHODS: A retrospective cohort study was conducted on twins delivered between 36 and 38 weeks of gestation from January 2008 to June 2020. The primary outcomes were the incidence of composite neonatal respiratory morbidity, which included respiratory distress syndrome, transient tachypnea of the newborn, meconium aspiration syndrome, mechanical ventilation or continuous positive airway pressure according to gestational age at delivery, and chorionicity. The relationship between gestational age at delivery and composite neonatal respiratory morbidity was evaluated using multivariate logistic regression analysis adjusted for potential confounders. RESULTS: This study included 1608 twins (614 monochorionic diamniotic twins, 994 dichorionic diamniotic twins). At 36, 37, and 38 weeks of gestation, the frequencies of composite neonatal respiratory morbidity were 19.4%, 10.7%, and 9.2% in dichorionic diamniotic twins and 13.6%, 8.7%, and 9.4% in monochorionic diamniotic twins, respectively. In dichorionic diamniotic twins, the composite neonatal respiratory morbidity rate was higher for twins delivered at 36 weeks of gestation than for those delivered at 37 weeks. No significant differences between monochorionic diamniotic twins were detected. CONCLUSIONS: In uncomplicated dichorionic diamniotic twin pregnancies, delivery should be considered after 37 weeks of gestation to reduce neonatal respiratory complications.

Risk of Transient Tachypnea of the Newborn following Elective Cesarean Section Increases at a Gestational Age of 37 Weeks Compared to That at ≥ 38 Weeks Despite the Exclusion of Pre-Existing Risk Factors for Neonatal Respiratory Disorders.

Background: Elective cesarean sections (ECSs) for early-term pregnancies at 37 weeks of gestational age (GA) aim to reduce the risk of emergency cesarean sections due to the onset of labor or rupture of membranes. However, resultant increases in neonatal respiratory disorders, including transient tachypnea of the newborn (TTN) have been observed. However, few studies have elucidated the associated risk factors. Consequently, we aimed to determine whether differences existed in the clinical outcomes between neonates delivered via ECS at 37 weeks and those delivered at ≥ 38 weeks of GA. Methods: A retrospective analysis was conducted on 259 neonates born via ECS at Tottori University Hospital, between January 2013 and December 2019, with birthweights ≥ 2500 g and GAs > 37 weeks. The neonates were categorized into two cohorts: births at 37 and at ≥ 38 weeks of GA (37-week and 38-week cohorts). The principal clinical outcomes included the appearance, pulse, grimace, activity, and respiration (Apgar) scores, need for positive-pressure ventilation, incidence of TTN, and length of hospital stay. Results: No statistically significant differences were observed in the indications for ECS, sex, or birthweight between the two cohorts. The 37-week cohort exhibited a lower 1-min Apgar score than did the 38-week cohort, with no statistically significant differences between the two cohorts, at 5 min. Statistically significant differences were not observed in the need for positive-pressure ventilation during initial resuscitation or length of hospital stay for patients with TTN between the two cohorts. Notably, the 37-week cohort exhibited a significantly higher incidence of TTN than did the 38-week cohort. Conclusion: ECSs at 37 weeks of GA exhibited an increased risk of TTN than ECSs at ≥ 38 weeks of GA. Strategic neonatal care and adequate preparation can mitigate this risk without affecting the length of hospital stay.

Safety and Efficacy of 2.5 mg and 1.25 mg Nebulized Salbutamol Compared with Placebo on Transient Tachypnea of the Newborns: A Triple-Blind Phase II/III Parallel Randomized Controlled Trial.

Background: To evaluate the safety and efficacy of 2.5 and 1.25 mg nebulized salbutamol on Transient Tachypnea of the Newborn (TTN) compared with placebo. Methods: We conducted a triple-blind, phase II/III parallel randomized controlled trial in two university-affiliated hospitals with neonatal intensive care units. Newborns with a confirmed diagnosis of TTN, with gestational age >35 weeks and gestational weight >2 kg were included. Cases of asphyxia, meconium aspiration syndrome, and persistent pulmonary hypertension were excluded. Ninety eligible patients were randomly allocated in three intervention groups (2.5 mg salbutamol, 1.25 mg salbutamol, and placebo), and a single-dose nebulized product was prescribed 6 hours after the birth. Safety outcomes included postintervention tachycardia, hyperglycemia, hypokalemia, and changes in blood pressure. To evaluate the efficacy, the duration of postintervention tachypnea, TTN clinical score, and clinical and paraclinical respiratory indices were assessed. Parents, Outcome assessors, and data analyzer were blind to the intervention. Results: There was no adverse reaction, including tachycardia, hypokalemia, and jitteriness. Both groups of salbutamol recipients showed significant improvement regarding respiratory rate, TTN clinical score, and oxygenation indices compared with the placebo (p-values <0.001). Nonstatistically significant higher hospital stay was observed in the placebo group. Single 2.5 mg salbutamol nebulization showed a little better outcome than the dose of 1.25 mg, although we could not find statistical superiority. Conclusion: The newly applied single high dose of 2.5 mg nebulized salbutamol is safe in treating TTN and leads to notable faster improvement of respiratory status without any considerable adverse reaction. Registry code: IRCT20190328043133N1.

Thoracic fluid content (TFC) using electrical cardiometry versus lung ultrasound in the diagnosis of transient tachypnea of newborn.

This study aimed to evaluate TFC by EC versus lung ultrasound (LUS) findings for diagnosing and follow-up of TTN in late preterm and term neonates. This prospective observational study was conducted on 80 neonates with gestational age ≥ 34 weeks. TTN group included 40 neonates diagnosed with TTN, and no lung disease (NLD) group included 40 neonates without respiratory distress. LUS and EC were performed within the first 24 h of life and repeated after 72 h. There was a statistically significant increase in TFC in TTN group on D1 [48.48 ± 4.86 (1 KOhm-1)] compared to NLD group [32.95 ± 4.59 (1 KOhm-1)], and then significant decrease in TFC in D3 [34.90 ± 4.42 (1 KOhm-1)] compared to D1 in the TTN group. There was a significant positive correlation between both TFC and LUS with Downes' score, TTN score, and duration of oxygen therapy in the TTN group.   Conclusion: Both LUS and TFC by EC provide good bedside tools that could help to diagnose and monitor TTN. TFC showed a good correlation with LUS score and degree of respiratory distress. What is Known: • Transient tachypnea of the newborn (TTN) is the most common cause of respiratory distress in newborns. • TTN is a diagnosis of exclusion, there are no specific clinical parameters or biomarker has been identified for TTN. What is New: • Thoracic fluid content (TFC) by electrical cardiometry is a new parameter to evaluate lung fluid volume and could help to diagnose and monitor TTN and correlates with lung ultrasound score.

Neonatal point-of-care lung ultrasound: what should be known and done out of the NICU?

Lung ultrasound is rapidly becoming a useful tool in the care of neonates: its ease of use, reproducibility, low cost, and negligible side effects make it a very suitable tool for the respiratory care of all neonates. This technique has been extensively studied by different approaches in neonatal intensive care unit (NICU), both for diagnostic and prognostic aims and to guide respiratory treatments. However, many neonates are being born in level I/II hospitals without NICU facilities so all pediatricians, not just neonatal intensivists, should be aware of its potential. This is made possible by the increasing access to ultrasound machines in a modern hospital setting. In this review, we describe the ultrasonographic characteristics of the normal neonatal lung. We also discuss the ultrasound features of main neonatal respiratory diseases: transient tachypnea of the neonate (TTN), respiratory distress syndrome (RDS), meconium aspiration syndrome (MAS), pneumothorax (PNX), pleural effusion (PE), or pneumonia. Finally, we mention two functional approaches to lung ultrasound: 1. The use of lung ultrasound in level I delivery centers as a mean to assess the severity of neonatal respiratory distress and request a transport to a higher degree structure in a timely fashion. 2. The prognostic accuracy of lung ultrasound for early and targeted surfactant replacement. CONCLUSION:  LU is still a useful tool in level I/II neonatal units, both for diagnostic and functional issues. WHAT IS KNOWN: • Neonatal lung ultrasound has been recently introduced in the usual care in many Neonatal Intensive Care Units. WHAT IS NEW: • It also has many advantages in level I/II neonatal units, both for neonatologist or even pediatricians that treat neonates in those sites.

Influence of the chest wall on respiratory function at birth in near-term lambs.

Airway liquid is cleared into lung tissue after birth, which becomes edematous and forces the chest wall to expand to accommodate both the cleared liquid and incoming air. This study investigated how changing chest wall mechanics affects respiratory function after birth in near-term lambs with different airway liquid volumes. Surgically instrumented near-term lambs (139 ± 2 days) were randomized into Control (n = 7) or Elevated Liquid (EL; n = 6) groups. Control lambs had lung liquid drained to simulate expected volumes following vaginal delivery. EL lambs had airway liquid drained and 30 mL/kg liquid returned to simulate expected airway liquid volumes after elective cesarean section. Lambs were delivered, transferred to a Perspex box, and ventilated (30 min). Pressure in the box was adjusted to apply positive (7-8 cmH2O above atmospheric pressure) or negative (7-8 cmH2O below atmospheric pressure) pressures for 30 min before pressures were reversed. External negative pressures expanded the chest wall, reduced chest wall compliance (CCW) and increased lung compliance (CL) in Control and EL lambs. External positive pressures compressed the chest wall, increased CCW and reduced CL in Control and EL lambs. External negative pressure improved pulmonary oxygen exchange, reducing the alveolar-arterial difference in oxygen (AaDO2) by 69 mmHg (95% CI [13, 125]; P = 0.016) in Control lambs and by 300 mmHg (95% CI [233, 367]; P < 0.001) in EL lambs. In contrast, external positive pressures impaired pulmonary gas exchange, increasing the AaDO2 by 179 mmHg (95% CI [73, 285]; P = 0.002) in Control and by 215 mmHg (95% CI [89, 343]; P < 0.001) in EL lambs. The application of external thoracic pressures influences respiratory function after birth.NEW & NOTEWORTHY This study investigated how changes in chest wall mechanics influence respiratory function after birth. Our data indicate that the application of continuous external subatmospheric pressure greatly improves respiratory function in near-term lambs with respiratory distress, whereas external positive pressures impair respiratory function. Our findings indicate that, during neonatal resuscitation at birth, the forces applied to the chest wall should not be ignored as they can have a major impact on neonatal respiratory function.

The diagnostic value of n-terminal probrain natriuretic peptides to differentiate neonatal pneumoniae and transient tachypnea of the newborn.

BACKGROUND: The primary objective of the study was to determine the diagnostic value of serum N-terminal probrain natriuretic peptide (NT-proBNP) levels to differentiate neonatal pneumonia (NP) and transient tachypnea of the newborn (TTN). The secondary objective was to investigate the prognostic role of NT-proBNP levels in neonates with severe respiratory distress (RD). METHODS: A prospective, observational, single-blinded study involving 58 late preterm and term newborns who were diagnosed with TTN or NP was conducted between June 2020 and June 2021 at a level-3 neonatal intensive care unit in Kirikkale University Faculty of Medicine. TTN and NP groups were compared for serum NT-proBNP levels measured at the 1st and 24th hours of life. Optimal cut-off NT-proBNP value was determined by Youden index to predict the diagnosis of NP. Lung ultrasound was used to support the diagnosis of TTN and NP. In addition, lung ultrasound score (LUS) was used to determine severe RD. RESULTS: The median of NT-proBNP level was significantly higher at the 24th hour of life in the NP group than in the TTN group, respectively 7263.5 pg/mL (1643-35,000) and 3308 pg/mL (69-19,746), p = 0.004. At a cut-off value of 5515.5 pg/mL, NT-proBNP had a sensitivity of 75% and specificity of 73.8% to predict NP [AUC= 0.749 (95% CI: 0.602-0.895; p = 0.004)]. The study population was divided into two groups as high score group (n: 23, LUS ≥ 7) and low score group (n: 35, LUS < 7) according to the LUS at the 6th hour of life. NT-proBNP values at 24th hour of life were 6320 pg/mL (69-35,000) in high score group and 3500 pg/mL (570-15,948) in low score group, p = 0.044. Duration of oxygen support (p = 0.006), noninvasive ventilation (p = 0.008) and NICU stay (p = 0.004) were higher in high-score group. DISCUSSION: NT-proBNP values at 24th hour of life can be used as a relatively early predictor in the differentiation between NP and TTN in late preterm and term neonates. In addition, elevated NT-proBNP values are related to the higher LUS which reflects the severity of RD regardless of diagnosis.

The effect of non-invasive high-frequency oscillatory ventilation on the duration of non-invasive respiratory support in late preterm and term infants with transient tachypnea of the newborn: a randomized controlled trial.

Nasal continuous positive airway pressure (nCPAP) is one of the most commonly used non-invasive respiratory support modes in neonates with transient tachypnea of the newborn (TTN). Non-invasive high-frequency oscillatory ventilation (nHFOV) is a non-invasive respiratory support mode that has been increasingly used in neonatal respiratory disorders. This prospective randomized controlled study compared the efficacy of nHFOV and nCPAP in reducing the duration of non-invasive respiratory support. Late preterm and term infants > 34 weeks' gestation were included in the study. The infants were randomly assigned to receive either nHFOV or nCPAP. Treatment was started with standard settings in both groups. Infants who met treatment failure criteria were switched to nasal intermittent mandatory ventilation for further positive-pressure support. A total of 60 infants were included in the study. Thirty of these infants were included in the nHFOV group and 30 were included in the nCPAP group. The median duration of non-invasive respiratory support was not significantly different between the two groups (21 h [IQR: 16-68] for nHFOV vs 15 h [IQR: 11-33] for nCPAP; p = 0.09). However, after adjusting for potential confounders, nHFOV was associated with a shorter duration of non-invasive respiratory support than nCPAP (adjusted mean difference: 16.3 h; 95% CI: 0.7 to 31.9; p = 0.04). nHFOV was well tolerated and did not increase the risk of complications.    Conclusion: Our findings suggest that nHFOV is an effective and safe ventilation mode for late preterm and term neonates with TTN.   Trial registry: Clinicaltrials.gov (NCT03006354). Date of registration: December 30, 2016. What is Known: • nHFOV is a ventilation model that has been increasingly used for the management of RDS. • TTN is one of the most common causes of neonatal respiratory distress. What is New: • nHFOV is associated with shorter duration of non-invasive respiratory support and duration of oxygen support. • nHFOV may be a safe and effective alternative to nCPAP for neonates with TTN.

Comparison of urine bisphenol A levels in transient tachypnea of the newborn and healthy newborns.

BACKGROUND: To investigate the relationship between neonatal urine bisphenol A (BPA) levels and the prevalence and prognosis of transient tachypnea of the newborn (TTN). METHODS: This prospective study was conducted between January and April 2020 in the Neonatal Intensive Care Unit (NICU) of Gaziantep Cengiz Gökçek Obstetrics and Pediatric Hospital. The study group consisted of patients diagnosed with TTN and the control group was made up of healthy neonates housed together with their mothers. Urine samples were collected from the neonates within the first 6 hours postnatally. RESULTS: Urine BPA levels and urine BPA/creatinine levels were statistically higher in the TTN group (P < 0.005). The receiver operating characteristic (ROC) curve analysis determined the cut-off value of urine BPA for TTN to be 1.18 µg/L (95% confidence interval [CI]: 0.667-0.889, sensitivity: 78.1%, and specificity: 51.5%) and the cut-off value of urine BPA/creatinine to be 2.65 µg/g (95% CI: 0.727-0.930, sensitivity: 84.4%, and specificity: 66.7%). Furthermore, the ROC analysis indicated that the cut-off value of BPA for neonates requiring invasive respiratory support was 15.64 µg/L (95% CI: 0.568-1.000, sensitivity: 83.3%, and specificity: 96.2%) and the cut-off value for BPA/creatinine was 19.10 µg/g (95% CI: 0.777-1.000, sensitivity: 83.3%, and specificity: 84.6%) among the TTN patients. CONCLUSIONS: BPA and BPA/creatinine values were higher in the urine of newborns diagnosed with TTN which is a fairly common cause of NICU hospitalization, in samples collected within the first 6 hours after birth, which may be a reflection of intrauterine factors.

Assessment of myocardial function in late preterm and term infants with transient tachypnea of the newborn using tissue Doppler imaging - a pilot observational study.

The aim of this study was to compare conventional and tissue Doppler echocardiography parameters between transient tachypnea of the newborn (TTN) and healthy control infants. This cross sectional pilot observational study was conducted in a level 3 neonatal care unit of India. Consecutively born late preterm and term infants (LPTI) with TTN were eligible for enrollment. Control group was selected from healthy LPTI. Conventional and tissue Doppler (myocardial velocities, myocardial performance index (MPI)) echocardiography was done within first 12 h (D1) and 48-72 h (D3) of life. Conventional echocardiography parameters were fractional shortening (FS), ejection fraction (EF), ventricular output, E/A ratio, fractional area change (FAC), tricuspid annular plane systolic excursion (TAPSE), pulmonary artery systolic pressure (PASP), and pulmonary artery acceleration to ejection time ratio (PATET). Baseline characteristics and echocardiography images were compared between TTN and control groups. Out of 60 infants enrolled, 34 from TTN and 20 from control group were finally analyzed. Mean (SD) gestational age and birth weight of the study population was 366/7(1.8) weeks and 2398(376) g respectively. Left ventricular (LV) parameters were similar between both groups. On D1, right ventricular (RV)e' was smaller (6.42(1) cm/s vs. 7.68(1.68) cm/s, p 0.022), and E/e' (7.79(1.51) vs. 6.08(2.59), p 0.037) was larger in TTN group, indicating RV diastolic dysfunction. RV MPI (0.61(0.11) vs. 0.44(0.12), p < 0.001) was also larger, signifying RV global myocardial dysfunction. Similar findings were observed on D3. PATET was lower in TTN group on both D1 (0.34 (0.05) vs. 0.42 (0.05), p < 0.001) and D3 (0.38 (0.05) vs. 0.43 (0.02), p 0.004) suggesting persistently raised pulmonary arterial pressure, although only 2 infants developed pulmonary hypertension identified by standard echocardiography.   Conclusion: Myocardial tissue Doppler imaging of TTN infants revealed occult right ventricular diastolic dysfunction secondary to persistently raised pulmonary arterial pressure. What is Known: •Transient tachypnea of the newborn may be associated with pulmonary arterial hypertension. What is New: •Tissue Doppler imaging in infants with transient tachypnea of the newborn revealed occult right ventricular diastolic dysfunction secondary to raised pulmonary arterial pressure, not detected by standard echocardiography.

Association between thiol-disulfide hemostasis and transient tachypnea of the newborn in late-preterm and term infants.

BACKGROUND: Transient tachypnea of the newborn (TTN), which is the most common respiratory disease in the neonatal period, increases respiratory workload in newborns. We purposed to evaluate the oxidative stress (OS) status and thiol disulfide hemostasis in late preterm and term newborns with TTN in this study. METHODS: The study was carried out in a single-centre neonatal intensive care unit to investigate the effect of continuous airway positive pressure (CPAP) on the oxidative system in newborns with TTN. Thiol (native and total) and disulfide levels, total antioxidant and oxidant status (TAS/TOS) and Oxidative stress index (OSI) levels were measured. RESULTS: Total thiol levels measured before treatment was 429.5 (369.5-487) µmol/L in the late preterm group and 425 (370-475) µmol/L in the term group (p = 0.741). We found significant changes in TOS, OSI and TAS levels after CPAP treatment in the late preterm group (p < 0.001, p < 0.001, p = 0.012 respectively). It was also found that the disulfide level, which was 26.2 (19.2-31.7) before the treatment, decreased to 19.5 (15.5-28.75) after the treatment (p = 0.001) in late preterms. CONCLUSION: CPAP treatment reduced the OS status burden associated with TTN in neonates. The late preterm newborns with TTN are more affected by OS and increased OS levels decrease with CPAP treatment.

Cardiopulmonary Ultrasound Patterns of Transient Acute Respiratory Distress of the Newborn: A Retrospective Pilot Study.

Acute transient respiratory distress in the first hours of life is usually defined as transient tachypnea of the newborn (TTN). TTN is a respiratory self-limiting disorder consequent to delayed lung fluid clearance at birth. While TTN is the most common etiology of respiratory distress near term, its pathogenesis and diagnostic criteria are not well-defined. Lung ultrasound and targeted neonatal echocardiography are increasingly being used to assess critically ill infants, although their combined use to improve diagnostic precision in neonatal intensive care units has not yet been described. This retrospective pilot analysis aimed to identify possible cardiopulmonary ultrasound (CPUS) patterns in term and late preterm infants suffering from transient respiratory distress and requiring non-invasive respiratory support. After retrospectively revising CPUS images, we found seven potential sonographic phenotypes of acute neonatal respiratory distress. Up to 50% of the patients presented with signs of increased pulmonary vascular resistance, suggesting that those patients may be diagnosed with mild forms of persistent pulmonary hypertension of the newborn. Approximately 80% of the infants with a history of meconium-stained amniotic fluid displayed irregular atelectasis, indicating that they may have suffered from mild meconium aspiration syndrome. CPUS evaluation may improve accuracy in the approach to the infants presenting with transient acute respiratory distress, supporting communication with the parents and carrying important epidemiological consequences.

Impact of restricting early-term deliveries on adverse neonatal outcomes: a statewide analysis.

BACKGROUND: The "39-Week Rule" was adopted by the American College of Obstetricians and Gynecologists in 2009 to eliminate nonmedically indicated (elective) deliveries before 39 weeks in an effort to improve neonatal outcomes. OBJECTIVE: Our primary objective was to quantify the effect of this policy change on adverse neonatal outcomes among a cohort of term births in South Carolina. STUDY DESIGN: Deidentified data from all births in the state of South Carolina from 2000 to 2008 (before the 39-week rule) and from 2013 to 2017 (after statewide implementation and enforcement of the rule) were obtained from the South Carolina Revenue and Fiscal Affairs Office. Demographic data and International Statistical Classification of Diseases and Related Health Problems Ninth/Tenth Revision codes were obtained for each birth. Our primary outcome was admission to a neonatal intensive care unit. Our secondary outcomes were respiratory morbidities (including respiratory distress syndrome and transient tachypnea of the newborn), hypoxic-ischemic encephalopathy, seizure, sepsis, birth injuries, hyperbilirubinemia, hypoglycemia, and feeding difficulties. Propensity score analysis was used to control for maternal age, body mass index, race, gestational hypertension, infection, placental abruption, and gestational and pregestational diabetes mellitus. After stratification by propensity score, the Cochran-Mantel-Haenszel test was used to compare groups. RESULTS: A total of 620,121 infants were liveborn at term during the 2 study periods. After implementation of the 39-week rule, there was a significant reduction in early-term deliveries. In adjusted analyses, neonatal intensive care unit admission was significantly more common in the postimplementation period. Respiratory morbidities were also significantly more common postimplementation. In contrast, there were significant reductions in birth injuries and hyperbilirubinemia in the postimplementation period. CONCLUSION: Implementation of the 39-week rule was associated temporally with an increase in adverse neonatal outcomes. The outcomes intended to be reduced by the 39-week rule, including neonatal intensive care unit admission and respiratory morbidity, seem to have increased in incidence despite adherence to the proposed guidelines.

New parameters on prediction of severity of transient tachypnea of the newborn.

BACKGROUND: Transient tachypnea of the newborn (TTN) is a common clinical problem that often occurs in the first hours of life. Although it is considered to be a benign clinical course, some cases may have severe symptoms and require ventilation support. In this study, we aimed to determine the association between the mean platelet volume (MPV), nucleated red blood cells (NRBCs), right ventricular systolic pressure (RVSP), and the severity of TTN. METHODS: Patients with TTN were divided into two groups according to Silverman score (<7: group 1 [n: 34] and ≥7: Group 2 [n: 30]). The groups were compared in terms of demographic characteristics, hematologic parameters, and RVSP within the first 24 hours after admission. RESULTS: Mean birth weight of the patients was 3033.4 ± 364.1 g and median gestational age was 38 weeks (min-max: 34-42). Patients in Group 2 were found to require higher nasal continuous positive airway pressure (nCPAP) support and longer duration of oxygen treatment (p: 0.001). Patients in Group 2 had significantly higher thrombocyte, absolute NRBCs count, NRBCs/100 WBCs, and RVSP levels (p < 0.05). Hemoglobin and hematocrit levels were found significantly higher in group 1(p < 0.05). In logistic regression analysis, NRBCs/100 WBCs was found to be the most important independent parameter that affects Silverman score at admission (OR: 7.065, CI: 1.258-39.670, p: 0.026). DISCUSSION: This is the first study that investigates the association between NRBCs, RVSP, and severity of TTN. We think that elevated NRBCs and RVSP values are helpful for clinicians in decision making for referral of the patients to a secondary or a tertiary level of NICU and also inform the families about prognosis.

Evaluating Clinical Outcomes and Physiological Perspectives in Studies Investigating Respiratory Support for Babies Born at Term With or at Risk of Transient Tachypnea: A Narrative Review.

Respiratory distress in the first few hours of life is a growing disease burden in otherwise healthy babies born at term (>37 weeks gestation). Babies born by cesarean section without labor (i.e., elective cesarean section) are at greater risk of developing respiratory distress due to elevated airway liquid volumes at birth. These babies are commonly diagnosed with transient tachypnea of the newborn (TTN) and historically treatments have mostly focused on enhancing airway liquid clearance pharmacologically or restricting fluid intake with limited success. Alternatively, a number of clinical studies have investigated the potential benefits of respiratory support in newborns with or at risk of TTN, but there is considerable heterogeneity in study designs and outcome measures. A literature search identified eight clinical studies investigating use of respiratory support on outcomes related to TTN in babies born at term. Study demographics including gestational age, mode of birth, antenatal corticosteroid exposure, TTN diagnosis, timing of intervention (prophylactic/interventional), respiratory support (type/interface/device/pressure), and study outcomes were compared. This narrative review provides an overview of factors within and between studies assessing respiratory support for preventing and/or treating TTN. In addition, we discuss the physiological understanding of how respiratory support aids lung function in newborns with elevated airway liquid volumes at birth. However, many questions remain regarding the timing of onset, pressure delivered, device/interface used and duration, and weaning of support. Future studies are required to address these gaps in knowledge to provide evidenced based recommendations for management of newborns with or at risk of TTN.

Role of lung ultrasound in diagnosing and differentiating transient tachypnea of the newborn and respiratory distress syndrome in preterm neonates.

Aim: To evaluate the accuracy of lung ultrasound in diagnosing and differentiating transient tachypnea of the newborn and respiratory distress syndrome in preterm neonates. Material and methods: This was a single-center study. From January 2020 to June 2021. A total of 100 preterm neonates, admitted to the neonatal intensive care unit with symptoms of respiratory distress within six hours of birth, including 50 diagnosed with transient tachypnea of the newborn and 50 with respiratory distress syndrome on the basis of clinical examination, laboratory testing, chest X-rays, were recruited in the study. Lung ultrasound was performed in each neonate by a senior radiologist who was blinded to the clinical diagnosis. Lung ultrasound findings in both conditions were analyzed and compared. Results: Pulmonary edema manifesting as alveolar-interstitial syndrome, double lung point sign and less commonly as white out lungs in the absence of consolidation has 100% sensitivity and specificity in diagnosing transient tachypnea of the newborn. A combination of three signs of consolidation with air or fluid bronchograms, white out lungs and absent spared areas has 100% sensitivity and specificity for diagnosing respiratory distress syndrome. Double lung point sign was seen only in infants suffering from transient tachypnea of the newborn and consolidation with air or fluid bronchograms only in cases of respiratory distress syndrome. Conclusion: Lung ultrasound can accurately diagnose and reliably differentiate transient tachypnea of the newborn and respiratory distress syndrome in preterm neonates. It has advantages that cannot be replicated by chest radiography. Lung ultrasound may be used as an initial screening tool.

Increased airway liquid volumes at birth impair cardiorespiratory function in preterm and near-term lambs.

Respiratory distress is relatively common in infants born at or near-term, particularly in infants delivered following elective cesarean section. The pathophysiology underlying respiratory distress at term has largely been explained by a failure to clear airway liquid, but recent physiological evidence has indicated that it results from elevated airway liquid at the onset of air-breathing. We have investigated the effect of elevated airway liquid volumes at birth on cardiorespiratory function in preterm and near-term lambs. Preterm (130 ± 0 days gestation, term ∼147 days gestation; n = 12) and near-term (139 ± 1 days gestation; n = 13) lambs were instrumented (to measure blood pressure, blood flow, and blood gas status) and, at delivery, airway liquid volumes were adjusted to mimic levels expected following vaginal delivery (Controls; ∼7 mL/kg) or elective cesarean section with no labor (elevated liquid (EL); 37 mL/kg). Lambs were delivered, mechanically ventilated, and monitored for blood gas status, oxygenation, ventilator requirements, blood flows (carotid artery and pulmonary artery), and blood pressure during the first few hours of life. Preterm and near-term EL lambs had poorer gas exchange and required greater ventilatory support to maintain adequate oxygenation. Pulmonary blood flow was reduced and carotid artery blood flow, mean arterial blood pressure, and heart rate were reduced in EL near-term but not preterm lambs. These data provide further evidence that greater airway liquid volumes at birth adversely affect newborn cardiorespiratory function, with the effects being greater in near-term newborns.NEW & NOTEWORTHY We provide evidence for adverse effects of elevated airway liquid volumes at birth on pulmonary blood flow and gas exchange in both preterm and near-term lambs, although the effects were greatest in near-term newborns. Our study is an important step toward understanding the fundamental physiology underlying the cardiorespiratory morbidity associated with near-term newborns with elevated airway liquid volumes leading to respiratory distress soon after birth.

Risk factors of transient tachypnea of the newborn developing into pulmonary hypertension of the newborn: a case-control study.

Background: Transient tachypnea of the newborn (TTN) is the consequence of delayed resorption of lung fluid. When TTN develops, the infant may develop severe hypoxemia and progress to persistent pulmonary hypertension of the newborn (PPHN). Objectives: To examine factors associated with the development of PPHN in TTN infants. Methods: This retrospective study comprised 23 infants in whom a diagnosis of TTN with PPHN (TTN-PPHN) was confirmed and 59 infants with severe TTN without PPHN who required mechanical ventilation between 2009 and 2018 at Songklanagarind Hospital, Thailand. Logistic regression was used to assess factors associated with TTN and PPHN. Results: The factors identified by univariate analysis that were associated with development of PPHN were oxygen saturation (SpO2) <90% and respiratory rate (RR) ≥70 breaths/min at the time of admission, mean airway pressure (MAP) ≥8 cmH2O, oxygen index (OI) ≥10, partial pressure of oxygen (PaO2) ≤60, partial pressure of carbon dioxide (PCO2) ≥45 mmHg, and infants who did not receive positive pressure ventilation (PPV). In multivariate analyses, RR ≥70 breaths/min (adjusted odds ratio [aOR] 9.96, 95% confidence interval [CI] 2.1-47.29, P < 0.001) and OI ≥10 (aOR 29.22, 95% CI 4.46-191.23, P < 0.001) remained statistically significantly associated with PPHN. Conclusions: High RR and high OI were factors associated with PPHN in TTN infants.

Prediction of Lung Maturity in Fetuses with Growth Restriction through Quantitative Ultrasound Analysis.

The present study aimed to evaluate the performance of QuantusFLM software, which performs quantitative analysis of lung tissue texture through ultrasound images, in predicting lung maturity in fetal growth restriction (FGR). We included patients with singleton gestations between 34 and 38 6/7 wk and divided them into two groups: FGR and control (appropriate for gestational age [AGA]). The images were captured by ultrasound according to a specific protocol up to 48 h before delivery and analyzed with QuantusFLM software. The main clinical outcome evaluated was lung maturity (i.e., the absence of neonatal respiratory morbidity). We included 111 patients; one was excluded because of low image quality, leaving 55 patients in each group. The FGR group had a lower birth weight (2207 g vs. 2891 g, p < 0.001) and a longer stay in the neonatal intensive care unit (NICU) (10 d vs. 5 d, p = 0.043). QuantusFLM software was able to predict lung maturity in FGR with accuracy, sensitivity, specificity and positive and negative predictive values of 94.5%, 96.2%, 50%, 98.1% and 33.3%, respectively. QuantusFLM had good accuracy in predicting lung maturity in FGR with reliability in identifying pulmonary maturity.