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.

Evolution of Ultrasound-Assessed Lung Aeration and Gas Exchange in Respiratory Distress Syndrome and Transient Tachypnea of the Neonate.

OBJECTIVE: To use clinical, lung ultrasound, and gas exchange data to clarify the evolution of lung aeration and function in neonates with respiratory distress syndrome (RDS) and transient tachypnea of the neonate (TTN), the most common types of neonatal respiratory failure. STUDY DESIGN: In this prospective observational cohort study, lung aeration and function were measured with a semiquantitative lung ultrasound score (LUS) and transcutaneous blood gas measurement performed at 1 hour (time point 0), 6 hours (time point 1), 12 hours (time point 2), 24 hours (time point 3) and 72 hours (time point 4) of life. Endogenous surfactant was estimated using lamellar body count (LBC). LUS, oxygenation index (OI), oxygen saturation index (OSI), and transcutaneous pressure of carbon dioxide (PtcCO2) were the primary outcomes. All results were adjusted for gestational age. RESULTS: Sixty-nine neonates were enrolled in the RDS cohort, and 58 neonates were enrolled in the TTN cohort. LUS improved over time (within-subjects, P < .001) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001). Oxygenation improved over time (within-subjects, P = .011 for OI, P < .001 for OSI) but was worse for the RDS cohort than for the TTN cohort at all time points (between-subjects, P < .001 for OI and OSI). PtcCO2 improved over time (within-subjects, P < .001) and was similar in the RDS and TTN cohorts at all time points. Results were unchanged after adjustment for gestational age. LBC was associated with RDS (ß = -0.2 [95% CI, -0.004 to -0.0001]; P = .037) and LUS (ß = -3 [95% CI, -5.5 to -0.5]; P = .019). CONCLUSIONS: For the first 72 hours of life, the RDS cohort had worse lung aeration and oxygenation compared with the TTN cohort at all time points. CO2 clearance did not differ between the cohorts, whereas both lung aeration and function improved in the first 72 hours of life.

Prenatal prediction of neonatal respiratory morbidity: a radiomics method based on imbalanced few-shot fetal lung ultrasound images.

BACKGROUND: To develop a non-invasive method for the prenatal prediction of neonatal respiratory morbidity (NRM) by a novel radiomics method based on imbalanced few-shot fetal lung ultrasound images. METHODS: A total of 210 fetal lung ultrasound images were enrolled in this study, including 159 normal newborns and 51 NRM newborns. Fetal lungs were delineated as the region of interest (ROI), where radiomics features were designed and extracted. Integrating radiomics features selected and two clinical features, including gestational age and gestational diabetes mellitus, the prediction model was developed and evaluated. The modelling methods used were data augmentation, cost-sensitive learning, and ensemble learning. Furthermore, two methods, which embed data balancing into ensemble learning, were employed to address the problems of imbalance and few-shot simultaneously. RESULTS: Our model achieved sensitivity values of 0.82, specificity values of 0.84, balanced accuracy values of 0.83 and area under the curve values of 0.87 in the test set. The radiomics features extracted from the ROIs at different locations within the lung region achieved similar classification performance outcomes. CONCLUSION: The feature set we designed can efficiently and robustly describe fetal lungs for NRM prediction. RUSBoost shows excellent performance compared to state-of-the-art classifiers on the imbalanced few-shot dataset. The diagnostic efficacy of the model we developed is similar to that of several previous reports of amniocentesis and can serve as a non-invasive, precise evaluation tool for NRM prediction.

Accuracy and Reliability of Lung Ultrasound to Diagnose Transient Tachypnoea of the Newborn: Evidence from a Meta-analysis and Systematic Review.

OBJECTIVE: Transient tachypnoea of the newborn (TTN) is one of the most common causes of neonatal respiratory distress (RD) during the newborn period. Chest radiography (CXR) is commonly used to rule out the diagnosis, but TTN is often misdiagnosed as neonatal respiratory distress syndrome (NRDS) on the basis of CXR alone. Increasing evidence suggests that lung ultrasound (LUS) may be a reliable diagnostic tool for transient tachypnoea of the newborn. However, studies of the diagnostic efficiency of LUS are still lacking. This study was aimed to evaluate the accuracy and reliability of LUS for diagnosing TTN by conducting a systematic review and meta-analysis. STUDY DESIGN: We searched for articles in the Embase, PubMed, and Cochrane Library databases from inception until May 31, 2020. The selected studies were diagnostic accuracy studies that reported the utility of LUS in the diagnosis of TTN. Two researchers independently extracted data and assessed quality using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. Then, we created a bivariate model of mixed effects to calculate the sensitivity and specificity of LUS in diagnosing TTN. A summary receiver operator characteristic (SROC) curve was constructed to summarize the performance characteristics of LUS. RESULTS: Six studies involving 617 newborns were included in the review. LUS had a pooled sensitivity of 0.98 (confidence interval [CI]: 0.92-1.00) and a specificity of 0.99 (CI: 0.91-1.00). The area under the curve for LUS was 1.00 (0.98-1.0). Meta-regression revealed that LUS had a significant diagnostic accuracy for TTN. CONCLUSION: The performance of ultrasound for the detection of TTN was excellent. Considering the various advantages of LUS compared with chest radiographs in diagnosing TTN, this study supports the routine use of LUS for the detection of TTN. KEY POINTS: · Lung ultrasound is a highly accurate diagnostic tool, which may be a viable and superior alternative to CXR, in diagnosing TTN.. · Lung ultrasound can help differentiate TTN from other etiologies of respiratory distress in neonates.. · There are still some controversies on the ultrasound diagnostic criteria of TTN..

Diagnostic performance of lung ultrasound for transient tachypnea of the newborn: A meta-analysis.

Several recent studies demonstrated that lung ultrasound could achieve desired diagnostic accuracy for transient tachypnea of the neonate (TTN). However, the diagnostic performance of lung ultrasound for TTN has not been systematically studied to date. This meta-analysis aimed to investigate the performance of lung ultrasound in diagnosing TTN. The relevant literature was searched in PubMed, Medline, the Cochrane Library, and Embase databases without any restriction in terms of language and time until January 31, 2021. Studies that assessed the diagnostic performance of lung ultrasound for TTN were included. Seven studies with 1514 participants were summarized. The lung ultrasound provided more accurate performance for diagnosing TTN with pooled sensitivity and specificity of 0.67 [95% confidence interval (CI) = 0.63-0.71] and 0.97 (95% CI = 0.95-0.98), respectively. A higher summarized area under the summary receiver operating characteristic curve was observed as 0.9906. Lower sensitivity and area under the curve (AUC) of B-lines for TTN were observed as 0.330 (95% CI = 0.27-0.38) and 0.5000, respectively. Lung ultrasound provided highly accurate AUC, sensitivity, and specificity in detecting TTN. Large-scale studies are warranted in the future to confirm these results.

Prospective investigation of serial ultrasound for transient tachypnea of the newborn.

BACKGROUND: Transient tachypnea of the newborn (TTN), which is diagnosed using typical clinical course and radiographic findings, is the most common cause of respiratory distress in late-preterm and term neonates. Lung ultrasound (LUS) is increasingly used to identify TTN according to the distinct characteristics of the disease. However, few studies have reported the application of LUS to monitor the clinical evolution of TTN. Using serial LUS, this prospective study assessed and monitored TTN severity. METHODS: From November 2018 to October 2019, neonates ≥34 weeks of gestation admitted to the newborn center of Chang Gung Memorial Hospital were enrolled. Neonates diagnosed with TTN and requiring respiratory support comprised the TTN group (n = 29), whereas those without respiratory disease served as the control group (n = 23). LUS was performed and scored in both groups within 4 h of admission and followed up at 24 and 48 h. RESULTS: A total of 65 infants were screened for enrollment and 13 were excluded. Most of the enrollees in both groups exhibited a peak LUS score on the first day, which then gradually declined thereafter. In comparison with the control group, the LUS score of the TTN group was higher on day 1 and day 2, and it had a significantly greater decrease from day 1 to day 2. In the TTN group, LUS scores moderately correlated with respiratory severity scores. CONCLUSION: We conducted a serial and quantitative LUS investigation in late-preterm and term infants with TTN. The LUS score mirrored the respiratory status relatively well, and it can help to monitor the clinical course of TTN, in the case of either resolution or deterioration.

Fetal Pulmonary Artery Acceleration/Ejection Ratio for Transient Tachypnea of the Newborn in Uncomplicated Term Small for Gestational Age Fetuses.

OBJECTIVE: Transient tachypnea of the newborn (TTN) is the leading cause of neonatal morbidity in preterm deliveries and has been reported in term small-for-gestational-age (SGA) fetuses; therefore, determination of fetal lung maturity before delivery is extremely important. Our present study aimed to evaluate the ratio of fetal pulmonary artery acceleration time to ejection time (At/Et) in uncomplicated term SGA fetuses and whether this ratio changes with TTN. STUDY DESIGN: One hundred seventy-five pregnant women with uncomplicated pregnancies who delivered after 37 gestational weeks were included in this cross-sectional study. Participants were divided by birth weight percentiles into SGA (n = 86) and healthy control groups (n = 89). All participants underwent ultrasound examination to determine fetal pulmonary artery At/Et. After delivery, the neonates were grouped according to diagnosis of TTN (i.e., TTN-positive SGA group [n = 14], TTN-negative SGA group [n = 72], and TTN-negative control group [n = 86]), and the fetal pulmonary artery At/Et was compared between the two. RESULTS: Maternal demographic characterizes were similar between groups. At/Et was 0.309 ± 0.181 in the SGA group and 0.348 ± 0.213 in the control group and was significantly lower in the SGA group. At/Et was 0.290 ± 0.007 in the TTN-positive SGA group, 0.313 ± 0.017 in the TTN-negative SGA group, and 0.351 ± 0.186 in the TTN-negative control group, a significant difference. Additionally fetal pulmonary artery At/Et was found to be inverse correlated with TTN. (-0,464 P = 0.000). The cut-off value of 0.298 provided optimal specificity of 93.0 % and sensitivity of 81.0 % for subsequent diagnosis of TTN in term SGA newborns in the neonatal period. CONCLUSION: The risk for TTN increases in uncomplicated term SGA fetuses. The fetal pulmonary artery At/Et appears to be a noninvasive useful method by which to predict TTN in these fetuses.

The utility of routine echocardiography in newborn infants with a persistent oxygen requirement

In the era of antenatal screening for congenital heart disease (CHD), infants presenting with an undiagnosed significant CHD are rare. However, term infants admitted with an initial diagnosis of TTN and a prolonged oxygen requirement often undergo an echocardiogram. We aimed to assess whether this practice yields any additional cases of undiagnosed CHD. We performed a retrospective chart review over a three year period [2013 ­ 2015] of term (> 36 weeks) infants admitted to the NICU for ≥ 5 days with a diagnosis of TTN and received an echocardiogram. The presence of CHD on the echocardiogram was assessed. Forty-seven infants were enrolled. The median age of echocardiogram was day four [2 ­ 8]. No infant had a diagnosis of significant CHD on the postnatal echocardiogram. A small muscular VSD was identified in two infants. Routine echocardiography for this cohort of infants to rule out major CHD appears to be unwarranted.

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.

Routine application of lung ultrasonography in the neonatal intensive care unit.

The aim of this study was to study the features of lung ultrasonography (LUS) in lung disease and to evaluate the usefulness of LUS in the neonatal intensive care unit (NICU).All of 3405 neonates included in this study underwent an LUS examination. Diagnoses were based on medical history, clinical manifestation, laboratory examination, and signs on chest radiography (CR) and/or computed tomography (CT). A single expert physician performed all LUS examinations.There were 2658 cases (78.9%) with lung disease and 747 cases (21.9%) without lung disease. The main signs of neonates with lung disease on LUS were as follows: absence of A-lines, pleural-line abnormalities, interstitial syndrome, lung consolidation, air bronchograms, pulmonary edema, and lung pulse. These abnormal signs were reduced or eliminated on LUS as patient conditions improved. There were 81 cases that could not be diagnosed as lung disease by CR but were discovered as pneumonia, respiratory distress syndrome (RDS), or transient tachypnea of newborn (TTN) on LUS. Likewise, 23 cases misdiagnosed as RDS by CR were diagnosed as TTN on LUS. Among 212 cases of long-term oxygen dependence (LTOD) that failed to yield signs of pulmonary edema and lung consolidation on CR, 103 cases showed abnormal signs on LUS. Among 747 cases without lung disease, B-lines of 713 neonates (95.4%) could be found within 3 days after birth, and 256 neonates (34.3%) could be observed from 3 days to 1 week after birth. B-lines of 19 cases could be detected from 1 to 2 weeks after birth. The longest time at which B-lines could still be observed was 19 days after birth.LUS has clinical value for the diagnosis of lung disease and the discrimination of causes of LTOP in premature infants, particularly for the diagnosis and identification of RDS and TTN. Moreover, LUS has additional advantages, including its lack of radiation exposure and its ability to noninvasively monitor treatment progress. Therefore, LUS should be routinely used in the NICU.

Lung Ultrasonography to Diagnose Transient Tachypnea of the Newborn.

BACKGROUND: This study explored the sensitivity and specificity of ultrasound for diagnosing transient tachypnea of the newborn (TTN). METHODS: Ultrasound was performed by one export. Patients were placed in a supine, lateral recumbent, or prone position. The probe was placed perpendicular or parallel to the ribs, and each region of the lung was scanned. The scan results were compared with conventional chest radiographic results. RESULTS: A total of 1,358 infants were included in this study. We identified 412 cases without pulmonary diseases, 228 TTN cases, 358 respiratory distress syndrome (RDS) cases, 85 meconium aspiration syndrome (MAS) cases, 215 infectious pneumonia cases, and 60 other cases. The primary ultrasonic characteristic of TTN was pulmonary edema. "White lung" or a "compact B-line" were only observed in severe cases, whereas TTN primarily presented as pulmonary interstitial syndrome or "double lung point." Furthermore, double lung point could appear during the recovery period of severe TTN or RDS, MAS, and pneumonia. Lung consolidation with air bronchograms was not observed in TTN patients. The results showed that white lung or a compact B-line exhibited a sensitivity of 33.8% and a specificity of 91.3% in diagnosing TTN, whereas double lung point exhibited a sensitivity of 45.6% and a specificity of 94.8% in diagnosing severe TTN. CONCLUSIONS: Pulmonary edema, alveolar-interstitial syndrome, double lung point, white lung, and compact B-line are the primary ultrasound characteristics of TTN. Ultrasonic diagnosis of TTN based on these findings is accurate and reliable. TTN can be ruled out in the presence of lung consolidation with air bronchograms.

Diagnosis of neonatal transient tachypnea and its differentiation from respiratory distress syndrome using lung ultrasound.

Transient tachypnea of the newborn (TTN) is one of the most common causes of perinatal dyspnea and is traditionally diagnosed by chest x-ray. This study aimed to explore the diagnostic value of lung ultrasonography (LUS) for TTN as well as differentiate it from respiratory distress syndrome (RDS) by using LUS. From January 2013 to February 2014, 60 infants who were diagnosed with TTN based on medical history, clinical manifestations, arterial blood gas analysis, and chest radiography were recruited to the study group. During the same period, 40 hospitalized neonates with nonlung diseases and 20 patients with RDS were recruited to the control group. In a quiet state, infants were placed in the supine, lateral, or prone position for the examination. Each lung of every infant was divided into 3 regions: the anterior, lateral, and posterior regions as bordered by the anterior axillary and posterior axillary lines. The probe was placed perpendicular to the ribs. Each region of both the lungs was carefully scanned.The common ultrasonographic manifestations of TTN were double-lung point (DLP), interstitial syndromes or white lungs, pleural line abnormalities, and A-line disappearance. A small number of infants (20%) with TTN exhibited pleural effusions, whereas the main ultrasonographic manifestation of RDS was lung consolidation with air bronchograms, which does not occur in TTN. The sensitivity and specificity of DLP for the diagnosis of TTN were 76.7% and 100%, respectively. LUS can accurately and reliably diagnose TTN. The DLP and lung consolidation possess great value in the diagnosis and differential diagnosis of TTN with RDS. Thus, we believe that LUS can be widely used in neonatal intensive care units.

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.