A randomized controlled trial of restricted versus standard fluid management in late preterm and term infants with transient tachypnea of the newborn.

BACKGROUND: Transient tachypnea of the newborn(TTNB) is the most common respiratory morbidity in late preterm and term babies and is pathophysiologically related to delayed lung fluid clearance after birth. Mimicking low physiological fluid intake in the initial period of life may accelerate the recovery from TTNB. In a randomized controlled trial, we compared the roles of restricted versus standard fluid management in babies with TTNB requiring respiratory support. METHODS: This parallel group,non-blinded, stratified randomized controlled trial was conducted in a level III neonatal unit of eastern India. Late preterm and term babies with TTNB requiring continuous positive airway pressure (CPAP) were randomly allocated to standard and restricted fluid arms for the first 72 hours (hrs). Primary outcome was CPAP duration. RESULTS: In total, 100 babies were enrolled in this study with 50 babies in each arm. CPAP duration was significantly less in the restricted arm (48[42, 54] hrs vs 54[48,72] hrs, p = 0.002). However, no difference was observed in the incidence of CPAP failure between the two arms. In the subgroup analysis, the benefit of reduced CPAP duration persisted in late preterm but not in term infants. However, the effect was not significant in the late preterm babies exposed to antenatal steroid. CONCLUSION: This trial demonstrated the safety and effectiveness of restrictive fluid strategy in reducing CPAP duration in late preterm and term babies with TTNB. Late preterm babies, especially those not exposed to antenatal steroid were the most benefitted by this strategy.

Transient Tachypnea of Newborns Is Associated With Maternal Spinal Hypotension During Elective Cesarean Delivery: A Retrospective Cohort Study.

BACKGROUND: The risk for transient tachypnea of newborns, a common cause of respiratory distress in the neonatal period, is 2- to 6-fold higher during elective cesarean delivery compared to vaginal delivery. Here, we evaluated the association between transient tachypnea of newborns and the degree and duration of predelivery maternal hypotension during spinal anesthesia for elective cesarean delivery. METHODS: Demographic data, details of anesthetic management, blood pressure measurements, and vasopressor requirement preceding delivery were compared between transient tachypnea newborns (n = 30) and healthy neonates (n = 151) with normal respiratory function born via elective cesarean delivery between July 2015 and February 2016. The degree and duration of hypotension were assessed using area under the curve for systolic blood pressure (SBP) ≤90 mm Hg and area under the curve for mean arterial pressure ≤65 mm Hg. After adjusting for confounders, multivariable logistic regression was used to evaluate the association between area under the curve for SBP and transient tachypnea of newborns. RESULTS: The median area under the curve for SBP was higher in cases of transient tachypnea of newborns (0.94; interquartile range, 0-28.7 mm Hg*min) compared to healthy controls (0; interquartile range, 0-3.30 mm Hg*min; P = .001). Similarly, median area under the curve for mean arterial pressure was also higher in cases of transient tachypnea of newborns (0; interquartile range, 0-18.6 mm Hg*min) compared to controls (0; interquartile range, 0-1.1 mm Hg*min; P = .01). Mothers of transient tachypnea newborns received significantly higher amounts of phenylephrine and ephedrine compared to controls (P = .001 and 0.01, respectively). Hence, the total vasopressor dose given to mothers in the transient tachypnea of newborn group was much higher than for the control group (P = .001). In the multivariable logistic regression, area under the curve for SBP was significantly associated with transient tachypnea of newborns (odds ratio, 1.02; 95% CI, 1.01-1.04, P = .005) after adjusting for gravidity and the type of anesthetic (spinal versus combined spinal epidural). CONCLUSIONS: Our results suggest that the degree and duration of maternal SBP <90 mm Hg after neuraxial anesthesia during elective cesarean delivery are associated with transient tachypnea of newborns. Future prospective studies should further explore the effects of maternal hypotension, its prevention, and treatment for transient tachypnea of newborns.

Lung ultrasound in early diagnosis of neonatal transient tachypnea and its differentiation from other causes of neonatal respiratory distress.

BACKGROUND: Transient tachypnea of the newborn (TTN) is one of the most common causes of neonatal respiratory distress (RD). However, distinguishing TTN from other causes of RD may be difficult during the first 12:24 h after birth. Lung ultrasonography (LUS) has been successfully utilized in the diagnosis and differential diagnosis of neonatal RD. This study aimed to investigate the diagnostic value of LUS for early diagnosis of TTN as well as differentiate it from other causes of neonatal RD in near and full term Egyptian neonates. METHODS: LUS was performed in 65 near and full term neonates presented with RD within the first 12:24 hours of admission in NICU of Suez Canal University, Ismailia, Egypt. RESULTS: Among the 65 neonates included in the study, 73.8% were diagnosed to have TTN, 18.5% were diagnosed to have pneumonia, 4.6% had meconium aspiration syndrome (MAS) and 3.1% had respiratory distress syndrome (RDS). The Double lung point has 69.6% sensitivity, 100% specificity, 100% PPV and 39.1% NPV for detecting TTN. We have novel data showing a positive correlation between the degree of alveolar-interstitial syndrome (AIS) and the type of oxygen support offered to neonates diagnosed with TTN. CONCLUSION: We found LUS to be a reliable and non-invasive tool for the early diagnosis of TTN and its differentiation from other causes of neonatal RD in near and full term Egyptian neonates.

Elevated airway liquid volumes at birth: a potential cause of transient tachypnea of the newborn.

Excessive liquid in airways and/or distal lung tissue may underpin the respiratory morbidity associated with transient tachypnea of the newborn (TTN). However, its effects on lung aeration and respiratory function following birth are unknown. We investigated the effect of elevated airway liquid volumes on newborn respiratory function. Near-term rabbit kittens (30 days gestation; term ~32 days) were delivered, had their lung liquid-drained, and either had no liquid replaced (control; n = 7) or 30 ml/kg of liquid re-added to the airways [liquid added (LA); n = 7]. Kittens were mechanically ventilated in a plethysmograph. Measures of chest and lung parameters, uniformity of lung aeration, and airway size were analyzed using phase contrast X-ray imaging. The maximum peak inflation pressure required to recruit a tidal volume of 8 ml/kg was significantly greater in LA compared with control kittens (35.0 ± 0.7 vs. 26.8 ± 0.4 cmH2O, P < 0.001). LA kittens required greater time to achieve lung aeration (106 ± 14 vs. 60 ± 6 inflations, P = 0.03) and had expanded chest walls, as evidenced by an increased total chest area (32 ± 9%, P < 0.0001), lung height (17 ± 6%, P = 0.02), and curvature of the diaphragm (19 ± 8%, P = 0.04). LA kittens had lower functional residual capacity during stepwise changes in positive end-expiratory pressures (5, 3, 0, and 5 cmH20). Elevated lung liquid volumes had marked adverse effects on lung structure and function in the immediate neonatal period and reduced the ability of the lung to aerate efficiently. We speculate that elevated airway liquid volumes may underlie the initial morbidity in near-term babies with TTN after birth.NEW & NOTEWORTHY Transient tachypnea of the newborn reduces respiratory function in newborns and is thought to result due to elevated airway liquid volumes following birth. However, the effect of elevated airway liquid volumes on neonatal respiratory function is unknown. Using phase contrast X-ray imaging, we show that elevated airway liquid volumes have adverse effects on lung structure and function in the immediate newborn period, which may underlie the pathology of TTN in near-term babies after birth.

Perfusion index assessment during transition period of newborns: an observational study.

BACKGROUND: Perfusion index (PI) is becoming a part of clinical practice in neonatology to monitor peripheral perfusion noninvasively. Hemodynamic and respiratory changes occur in newborns during the transition period after birth in which peripheral perfusion may be affected. Tachypnea is a frequent symptom during this period. While some tachypneic newborns get well in less than 6 h and diagnosed as "delayed transition", others get admitted to intensive care unit which transient tachypnea of newborn (TTN) being the most common diagnosis among them. We aimed to compare PI of neonates with TTN and delayed transition with controls, and assess its value on discrimination of delayed transition and TTN. METHODS: Neonates with gestational age between 37 and 40 weeks who were born with elective caesarian section were included. Eligible neonates were monitored with Masimo Set Radical7 pulse-oximeter (Masimo Corp., Irvine, CA, USA). Postductal PI, oxygen saturation and heart rate were manually recorded every 10 s for 3 min for two defined time periods as 10th minute and 1st hour. Axillary temperature were also recorded. Newborn infants were grouped as control, delayed transition, and TTN. RESULTS: Forty-nine tachypneic (TTN; 21, delayed transition; 28) and 30 healthy neonates completed the study. PI values were similar between three groups at both periods. There were no correlation between PI and respiratory rate, heart rate, and temperature. CONCLUSION: PI assessment in maternity unit does not discriminate TTN from delayed transitional period in newborns which may indicate that peripheral perfusion is not severely affected in either condition.

Increased asymmetric dimethylarginine levels in severe transient tachypnea of the newborn.

OBJECTIVE: Nitric oxide (NO) is synthesized by NO synthase (NOS), and asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NOS. We aimed to investigate l-arginine and ADMA levels in transient tachypnea of the newborn (TTN) and their relationship with systolic pulmonary artery pressure (PAP) and disease severity. STUDY DESIGN: Infants born at ⩾35 weeks gestational age with clinical signs and chest X-ray findings consistent with TTN were enrolled; controls were recruited at the same time. l-arginine and ADMA levels were measured at 12 to 24 h (first samples) and at 48 to 72 h (second samples). Systolic PAP was evaluated on the second day. Patients were divided according to the duration of tachypnea and designated as group A (duration ⩽72 h) and group B (duration >72 h). RESULTS: In the first samples, the ADMA levels were significantly higher in patients with TTN compared with controls (P<0.001). In the second samples, the ADMA levels were significantly higher in group B compared with that in group A (P=0.019). In group A patients, the second ADMA levels were significantly lower compared with that in the first samples (P<0.001), whereas the second ADMA levels remained unchanged compared with the first samples in group B. Systolic PAP values were significantly higher in group B compared with that in group A patients (P=0.033). CONCLUSION: Increased ADMA concentration may reduce NO synthesis, leading to increased PAP and thus longer duration of tachypnea.

Surfactant deficiency in full-term newborns with transient tachypnea delivered by elective C-section.

INTRODUCTION: Previous studies have suggested that full-term newborns delivered by elective cesarean section who develop transient tachypnea have low gastric microbubble counts. In the present study, microbubble concentrations in oral fluid samples were used to evaluate pulmonary maturity. OBJECTIVE: To evaluate lung maturity in full-term newborns delivered by elective caesarean section using the stable microbubble test in oral aspirates collected at birth. METHOD: The study involved newborns with gestational age >37 weeks delivered by elective cesarean section. Oral fluid samples were obtained in the delivery room immediately after birth, and gastric fluid was collected within the first hour of life. Samples were frozen and analyzed by two blinded researchers. RESULTS: The sample comprised 544 newborns. Twenty-two were diagnosed with transient tachypnea of the newborn by the assisting physician, and required admission to the Neonatal Intensive or Intermediate Care Unit. The median (interquartile range) of the number of microbubbles in the oral samples of these patients was 67.5 (45-150) microbubbles/mm(2) . The remaining 498 newborns without respiratory difficulties had a count of 350 (150-750) microbubbles/mm(2) -P < 0.001. Gastric fluid tests revealed a count of 150 (82.5-700) microbubbles/mm(2) for neonates with respiratory difficulties, and of 600 (216-1125) microbubbles/mm(2) -P < 0.05 for those without respiratory symptoms. CONCLUSION: The present results suggest that transient tachypnea of the newborn is associated with surfactant dysfunction. Pediatr Pulmonol. 2016;51:596-600. © 2015 Wiley Periodicals, Inc.

Dopamine treatment does not need speed recovery of newborns from transient tachypnea.

OBJECTIVE: Transient tachypnea of the newborn (TTN) results from inadequate neonatal lung fluid clearance. Low-dose dopamine induces natriuresis in the kidneys and it has been assumed that, at this low dosage, dopamine increases renal perfusion in critically ill patients. Medium doses have positive inotropic and chronotropic effects via increased ß-receptor activation. Recent studies have demonstrated that dopamine stimulates the clearance of pulmonary edema. Furthermore, ß-adrenergic agonists regulate Na+ channels and Na-K-ATPase activity in the pulmonary epithelium. This study investigated the effect of dopamine at different dosages on TTN treatment. METHODS: A prospective controlled study examined 60 infants with TTN older than 34 weeks of gestation who required at least 24 h of O2 and nasal continuous positive airway pressure (nCPAP) treatment. The infants were randomized into three groups of 20: controls, infants treated with low-dose dopamine (3 µg/kg/min), and infants treated with a medium dose (5 µg/kg/min). The control and study groups were compared in terms of the requirement for mechanical ventilation, and the durations of nCPAP, oxygen requirement, and hospitalization. RESULTS: The requirement for mechanical ventilation, and durations of nCPAP, oxygen requirement, and hospitalization did not differ significantly among the three groups (P=0.54, 0.16 and 0.11, respectively). CONCLUSION: Dopamine treatment in low-moderate doses does not improve the outcome in TTN. Thus, further studies in this area are needed.

Risk assessment for neonatal RDS/TTN using gestational age and the amniotic lamellar body count in twin pregnancies.

BACKGROUND: The amniotic lamellar body count (LBC) is useful for predicting respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN) in twin pregnancies. However, the risk of neonatal respiratory complications varies with gestational age (GA). We herein created a model to predict the risk for RDS and TTN using GA and the LBC in twin pregnancies. METHODS: Six hundred thirty-two amniotic fluid samples, comprising 169 dichorionic twin (DCT) and 147 monochorionic twin (MCT) gestations, were obtained at Cesarean section. The samples were analyzed immediately without centrifugation. A logistic regression model including the LBC and GA was used to develop the prediction model for RDS/TTN. RESULTS: There were 101 neonates (16.0%) with RDS/TTN. The GA and LBC were significant independent factors affecting RDS/TTN. According to the logistic regression model, we determined the probability of RDS/TTN given the values of GA and the LBC. The overall diagnostic accuracy for predicting neonatal RDS/TTN using GA and the LBC was higher than the use of the LBC alone. CONCLUSIONS: GA-specific LBC cutoffs for the risk assessment of neonatal RDS/TTN have been considered to be more accurate in twin pregnancies. Our findings provide valuable, new information for the management of twin pregnancies.

Risk factors in retained fetal lung fluid syndrome.

OBJECTIVE: Antenatal, postnatal follow-ups and laboratory findings of the cases with retained fetal lung fluid syndrome were evaluated to detect prognostic factors. STUDY DESIGN: This study was conducted at Zeynep Kamil Maternity and Children's Training and Research Hospital including infants retained fetal lung fluid syndrome. Patients were divided into 3 groups according to duration of the clinical symptoms. Cases whose clinical findings resolving within first 24 hours constituted Group 1 (n = 31), cases with clinical findings persisting between 24 and 72 hours constituted Group 2 (n = 95) and cases with symptoms persisting >72 hours constituted Group 3 (n = 10). Antenatal and postnatal clinical data and laboratory findings of the patients were evaluated retrospectively. RESULT: Pneumothorax, pulmonary hypertension, antibiotic use frequency and hospitalization periods were found to be prolonged in the patients admitted due to retained fetal lung fluid syndrome who were delivered with elective caesarean section, with low birth weight and gestational age, requiring intubation and invasive ventilation within first 12 hours, having low hemoglobin and blood chloride levels. CONCLUSIONS: Low blood chloride level can be a laboratory finding predicting whether malignant tachypnea develops or not in retained fetal lung fluid syndrome. Cut-off chloride value for malignant tachypnea can be determined with new studies which will be performed in the future.

Lung ultrasound accuracy in respiratory distress syndrome and transient tachypnea of the newborn.

BACKGROUND: Lung ultrasound (LUS) is a promising technique for the diagnosis of neonatal respiratory diseases. Preliminary data has shown a good sensitivity and specificity of LUS in the diagnosis of respiratory distress syndrome (RDS) and transient tachypnea of the newborn (TTN). OBJECTIVE: The aim of this study was to calculate the sensitivity, specificity, and negative (NPV) and positive predictive value (PPV) of LUS for RDS and TTN, using an external reader blinded to the clinical condition. DESIGN AND METHODS: Neonates with respiratory distress had a LUS within 1 h of admission. Images were uploaded and sent to the external reader, who made the ultrasound diagnosis according to the appearance of the images. The final clinical diagnosis was made according to all the available data, except LUS data. Sensitivity, specificity, PPV, and NPV were calculated considering the final clinical diagnosis as the gold standard. RESULTS: Fifty-nine neonates were studied (mean gestational age: 33 ± 4 weeks, mean birth weight: 2,145 ± 757 g). Twenty-three infants had a final diagnosis of RDS and 30 of TTN. LUS showed a sensitivity of 95.6% and specificity of 94.4%, with a PPV of 91.6% and a NPV of 97.1% for RDS, and a sensitivity of 93.3% and specificity of 96.5% with a PPV of 96.5% and a NPV of 93.4% for TTN. CONCLUSIONS: LUS showed high sensitivity and specificity in diagnosing RDS and TTN.

Developmental physiology of late and moderate prematurity.

This is a brief review of the developmental physiology of selected organ and functional systems in moderate and late preterm infants. This outline provides a discussion of the physiological underpinnings for some of the clinical conditions seen in this group of infants, including hypothermia, hypoglycemia, respiratory distress syndrome, transient tachypnea, severe respiratory failure, apnea, feeding difficulties, jaundice, and increased susceptibility to infections.

Correlation between transient tachypnea of the newborn and wheezing attack.

BACKGROUND: Transient tachypnea of the newborn (TTN) is the most common cause of respiratory distress in newborns. Although associated with some morbidity, it is generally believed that once TTN resolves, there is no further increased risk for respiratory disease. However, in limited studies frequency of wheezing attacks is found to be increased in patients who had TTN diagnosis during the newborn period, in comparison to patients who had no respiratory problem. Thus, the question arises as to whether TTN is an innocent disease. METHODS: This study was done retrospectively. We recorded the demographic characteristics of 103 infants born between 17 October 2003 and 17 October 2004 at Zeynep Kamil Hospital and hospitalized because of TTN in the neonatal intensive care unit. In the second phase, we telephoned the parents of the 103 infants and asked about wheezing attacks. A total of 103 other infants, born during the same period, with no health problems during the newborn period, were included in the study as the control group and the same procedures were applied to them. RESULTS: The rate of wheezing attack among patients with TTN diagnosis was found to be significantly higher than that in patients who had no TTN diagnosis (P < 0.01). TTN was found to be an independent risk factor for wheezing attack (OR, 2.378; 95% CI, 1.20-4.70). CONCLUSION: In conclusion, we established that TTN is an independent risk factor for wheezing. In addition we also hypothesized that genetic and environmental interactions synergistically predisposed these children for future wheezing.