Pulmonary Artery Doppler Research Articles

Prenatal Ultrasound Markers: A Comparative Study for Prediction of Respiratory Distress in Early Preterm Newborns.

This study aimed to compare the prenatal ultrasound parameters- fetal lung biometry and pulmonary artery Doppler in preterm newborns for prediction of respiratory distress (RD). A prospective analytic study was conducted in Department of Obstetrics and Gynecology in collaboration with Department of Neonatalogy. Fetal ultrasound and Doppler parameters were evaluated in women predisposed to have preterm delivery at or before 34weeks. The neonates were followed for occurrence of RD. Out of 100 study population, neonates who developed RD were taken as cases (n = 36) and rest were grouped as controls (n = 64). The gestational age at delivery, mean birth weight and Apgar score were significantly less in cases than controls. All the fetal lung biometric parameters were significantly less in cases than controls (p value < 0.001). The fetal lung volume had highest sensitivity (72.22%) and negative predictive value (83%). The right lung area had highest specificity (89%) and positive predictive value (72%). Among the Doppler parameters, the At/Et ratio showed high degree of accuracy (68%). The sensitivity and specificity were 55.56% and 75%, respectively. The positive and negative predictive values were 72% and 60%, respectively. Both fetal lung biometry and pulmonary artery Doppler offer an excellent noninvasive approach for assessment of fetal lung maturity, clinically assessed by RD. On comparison of all the ultrasound parameters, fetal lung volume and At/Et ratio showed highest degree of accuracy in prediction of RD.

Fetal pulmonary artery doppler parameters in pregnancies complicated with intrahepatic cholestasis of pregnancy: a prospective case-control study.

The primary aim of this study was to determine whether PATET was altered in the fetuses whose mothers were complicated by intrahepatic cholestasis of pregnancy (IHCP). The secondary aim was to investigate the association between fetal pulmonary artery Doppler parameters with neonatal outcomes in pregnancies complicated by IHCP. This prospective case control study was conducted in a tertiary perinatal- neonatal center. A total of 18 fetuses whose mothers were complicated by IHCP were set as the study group and a total of 37 fetuses whose mothers were healthy were selected as the control group. Fetal pulmonary artery Doppler parameters (acceleration time -AT; ejection time -ET; AT/ET ratio) were assessed and neonatal outcomes were evaluated. Mean pulmonary artery AT, ET, PATET were statistically significant different between the groups (p=0,001; p=0,024 and p=0,003, respectively). The mean PATET value in the IHCP group was 0,217 ± 0,029 while in the control group it was 0,180 ± 0,020 (p=0,003). While PATET values were correlated with gestational age at birth, respiratory distress and NICU admission were not correlated with PATET. Higher values of PATET may be helpful to understand fetal lung damage secondary to IHCP. of PATET may be helpful to understand fetal lung damage secondary to IHCP.

Correlation between Progesterone as a Treatment of Preterm Labor and Changes in Fetal Pulmonary Artery Doppler

Correlation between Progesterone as a Treatment of Preterm Labor and Changes in Fetal Pulmonary Artery Doppler

The Role of Fetal Pulmonary Artery Doppler in Prediction of Fetal Lung Maturity

The Role of Fetal Pulmonary Artery Doppler in Prediction of Fetal Lung Maturity

Pulmonary artery dopplers for early prediction of risk for bronchopulmonary dysplasia in extremely low birth weight babies.

The early abnormal pulmonary vasoreactivity observed in babies at risk of Bronchopulmonary dysplasia (BPD) increases the pulmonary vascular resistance. This can be assessed non-invasively using Time to Peak Velocity:Right Ventricular Ejection Time ratio (TPV:RVET) measured from pulmonary artery Doppler waveform obtained using echocardiogram. We postulate that screening for this early can predict BPD in this cohort. The objective of the study was to determine the utility of TPV:RVET in early prediction of BPD in Extremely Low Birth Weight (ELBW) babies born less than 1250grams Birth Weight. This was a single-center retrospective cohort study of ELBW babies born<29 weeks over 4 year period who had echocardiogram between 7-21 days of life. TPV:RVET ratio was measured from pulmonary artery Doppler waveform obtained using echocardiogram. The main outcome was BPD at 36 weeks corrected gestation. The predictive ability of TPV:RVET (cut off 0.34) for subsequent development of BPD was analyzed using ROC. Of 589 ELBW<29 weeks, 207 babies were eligible. BPD was found in 60.4%. The TPV:RVET at 0.34 had sensitivity 76.8% (95%CI 68.4-83.9), specificity 85.4% (95%CI 75.8-92.2), positive predictive value 88.9% (95%CI 81.4-94.1), negative predictive value 70.7% (95%CI 60.7-79), and ROC area 0.811 (95%CI 0.757-0.864). Odds ratio of having BPD for TPV:RVET at 0.34 was 19.9 (95%CI 8.19-48.34) and increased by 1.07 (95%CI 1.05-1.09) with every additional days of mechanical ventilation. TPV:RVET ratio had 92.75% inter-observer agreement with kappa 0.83. TPV:RVET ratio is a good and reliable early screening tool for subsequent development of BPD in ELBW babies with substantial inter-observer agreement.

Role of Fetal Pulmonary Artery Doppler in predicting risk of neonatal respiratory distress syndrome

INTRODUCTION- To determine the optimal time to safely deliver a baby prematurely due to various clinical situations, it is crucial to accurately assess fetal lung maturity. Sonography which is a non-invasive technique for evaluating fetal lung maturity can be useful in predicting risk for developing neonatal respiratory distress as compared to amniocentesis which is an invasive procedure with associated risks. AIM - Purpose of this study was to determine if fetal main pulmonary artery doppler can play a role in predicting the risk of developing respiratory distress syndrome in neonates. MATERIAL AND METHODS – The participants in this prospective cross-sectional study were 75 pregnant women with gestational ages ranging from 34weeks to 36 weeks +6 days. Ultrasound doppler examination was conducted and peak systolic velocity (PSV), Systolic /Diastolic ratio, pulsatility index, resistive index were measured and acceleration time/ejection time ratio was calculated for the fetal main pulmonary artery. Diagnostic accuracy of these values was tested for predicting neonatal respiratory distress. RESULT - Of the 75 fetuses included in the study, 15 (20%) showed some signs of neonatal respiratory distress syndrome (RDS). The Acceleration time/Ejection time (AT/ET) ratio in fetal pulmonary artery correlated significantly with development of respiratory distress syndrome in neonates (P=0.001). Fetuses with respiratory distress syndrome had higher Pulsatility Index and Resistive Index values, while their AT/ET ratio was low. AT/ET was found to predict respiratory distress development with a cutoff value of 0.30 (sensitivity: 98.3 percent; specificity: 86.67 percent). Pulsatility Index and Resistive Index displayed lower sensitivity and specificity than AT/ET ratio. CONCLUSION- The fetal main pulmonary artery AT/ET ratio has a high sensitivity and specificity for predicting the development of neonatal respiratory distress syndrome. Thus, we recommend that a fetus with an AT/ET ratio of &lt;0.30 be delivered in a facility with good neonatal care.

Fetal Pulmonary Artery Doppler as Non Invasive Predictor for Lung Maturity in Diabetic Patients: Does it Help?

Fetal Pulmonary Artery Doppler as Non Invasive Predictor for Lung Maturity in Diabetic Patients: Does it Help?

Prenatal prediction of respiratory distress syndrome by multimodality approach using 3D lung ultrasound, lung-to-liver intensity ratio tissue histogram and pulmonary artery Doppler assessment of fetal lung maturity

Studying the correlation of different lung parameters, using three-dimensional ultrasound (3D US) with fetal lung maturity (FLM) to predict the development of neonatal respiratory distress syndrome (RDS). Three-dimensional ultrasound was done to record the fetal lung volume (FLV), fetal lung-to-liver intensity ratio (FLLIR) and the main pulmonary artery (MPA) blood flow parameters; pulsatility index (PI), resistive index (RI) and acceleration time-to-ejection time ratio (At/Et), to 218 women between 32 and 40 weeks gestational age within 24 h from labor. Of 218 fetuses examined, final analysis was done for 143 fetuses. Thirty eight (26.5%) were diagnosed with RDS. The MPA PI and RI were significantly higher in fetuses diagnosed with RDS compared with those without (2.51 ± 0.33 and 0.90 ± 0.03 cm/s versus 1.96 ± 0.20 and 0.84 ± 0.01 cm/s; p value < 0.001 and <0.001 respectively). MPA At/Et was significantly lower (0.24 ± 0.04 vs 0.35 ± 0.04; p value < 0.001). FLLIR was significantly lower (1.04 ± 0.07 vs 1.18 ± 0.11; p value < 0.001), and the mean FLV was significantly smaller (28.23 ± 5.63, vs 38.87 ± 4.68 cm3; p value < 0.001). Main pulmonary artery (PI, RI, At/Et ratio), FLIIR, and mean FLV can be used as reliable predictors of neonatal RDS. 3D ultrasound VOCAL technique, ultrasound tissue histogram and pulmonary artery Doppler are reliable tools for prenatal prediction of fetal lung maturity.

Prediction of Fetal Lung Maturity by Fetal Pulmonary Artery Doppler in Cases of Severe Pre-Eclampsia

Background: Severe pre-eclampsia occurring remote from the term is a decision-making dilemma for the obstetrician, the general recommendation is that women with severe pre-eclampsia should be delivered to avoid maternal complications; others recommend prolonging pregnancy in most cases of severely premature pre-eclamptic gestation until the development of fetal lung maturity, development of fetal or maternal distress, or achievement of gestational age of 34 to 36-week of gestation. The cut-off level of pulmonary artery acceleration time to ejection time ratio [PAT/ET] that determines fetal lung maturity in cases of severe pre-eclampsia [PE] is not determined yet.Aim of the work: To study the Doppler indices of the main fetal pulmonary artery and their role in predicting respiratory distress syndrome [RDS] in severe pre-eclampsia.Patients and Methods: A prospective longitudinal cohort research was designed in which 102 pregnant women with PE were chosen and fetal pulmonary artery flow velocity data were acquired by Doppler ultrasound and linked with the development of neonatal RDS.Results: The AT/ET ratio in the fetal pulmonary artery velocity waveform was found to be directly related to the development of newborn RDS. A cut-off value of 0.3 resulted in a sensitivity of 71.4%, specificity of 79.7%, and total accuracy of 77.5%.Conclusion: A high AT/ET ratio in the fetal pulmonary artery is related to the future development of RDS in neonates of mothers with severe pre-eclampsia, implying that fetal pulmonary artery Doppler ultrasound may be a valuable tool in the identification of fetal lung maturity in situations of severe pre-eclampsia.

Fetal pulmonary artery Doppler evaluation in pregnant women after recovery from COVID‐19

ObjectiveTo evaluate fetal lung development using pulmonary artery Doppler in pregnant women who had recovered from COVID‐19.MethodsThe prospective case–control study included 41 pregnant women who had recovered from COVID‐19 and 43 healthy pregnant women (control group). All the women in the study group had been diagnosed with COVID‐19 and had completed a quarantine period.ResultsThe demographic data of patients were similar in the groups (P > 0.05). Main pulmonary artery peak systolic velocity was higher and pulsatility indices were lower in pregnant women who recovered from COVID‐19 compared to the controls (P < 0.001, P = 0.001). Acceleration time, ejection time, and acceleration/ejection time ratio (PATET) of the fetal MPA Doppler were significantly decreased in pregnant women who recovered from COVID‐19 (P < 0.001, P = 0.036, and P = 0.002, respectively). The patients who had recovered from COVID‐19 were divided into two groups: those treated with expectant management and those treated in hospital. The pulmonary artery acceleration time and PATET ratio were significantly lower in the group treated in the hospital (P = 0.023 and P = 0.045, respectively).ConclusionDetailed Doppler evaluations of the pulmonary artery may help in evaluating the fetal adverse effects of COVID‐19 disease.

Effects of nifedipine on fetal pulmonary blood flow in preterm labor

Objective To determine the effect of nifedipine on the fetal pulmonary system by acceleration/ejection time ratio of the fetal main pulmonary artery Doppler waveform. Methods This prospective study was conducted in a high-risk pregnancy clinic with pregnant women who required nifedipine treatment to prevent preterm labor between 24 and 34 weeks of gestation. An ultrasound examination that included measurements of the acceleration time (AT), ejection time (ET), and AT/ET ratio (PATET) were performed before and 48 h after the first nifedipine dose. Results Forty-three pregnant women were included in this study. AT and PATET found higher in the after nifedipine group when compared with before nifedipine group. When the ET parameters were compared, no differences were detected between the groups. Conclusion Nifedipine increases fetal pulmonary blood flow which appears to increase AT and PATET on Doppler parameters in pregnant women with preterm labor after 48h treatment.

Prognostic implications of pulmonary wave reflection and reservoir pressure in patients with pulmonary hypertension

BackgroundRight ventricular (RV) coupling to the pulmonary circulation influences the response of the RV to the increased afterload caused by pulmonary hypertension (PH), which ultimately determines prognosis. A methodology that accounts for pulsatile flow is required when assessing ventriculo-arterial coupling. We applied wave intensity analysis (WIA) methods to assess the compliance of the main pulmonary artery (PA) in patients with or without PH and compared this to PA distensibility, RV function and clinical outcomes. MethodsHigh-fidelity blood pressure and Doppler flow velocity tracings were obtained simultaneously during cardiac catheterisation for suspected PH. RV volumes, main PA distensibility and ventriculo-arterial coupling (Emax/Ea) were analysed using cardiovascular magnetic resonance. ResultsThe study included 17 ​PH patients and 6 controls. Wave speed, reservoir and excess pressure were higher in PH patients compared to controls (p ​< ​0.01 for all). Waveforms relating to RV ejection, microvascular wave reflection and late systolic proximal deceleration were higher in PH patients compared to controls (p ​< ​0.01 for all) and related to echocardiographic findings, including PA Doppler notching and shortened acceleration time. Wave speed, reservoir pressure and excess pressure were strongly correlated to main PA distensibility, RV function and Emax/Ea. A higher total pressure integral was associated with an increased risk of death (all-cause mortality). ConclusionThe reservoir-excess pressure model, in combination with conventional clinical imaging, provides valuable information on the pathophysiology of PH that standard haemodynamic parameters do not. Future studies should further investigate the prognostic implications of WIA in PH, and its potential role in clinical practice.

Effects of SARS-COV-2 infection on fetal pulmonary artery Doppler parameters.

PurposeTo determine the effect of SARS‐CoV‐2 infection on the fetal pulmonary system using the acceleration time (AT), ejection time (ET), and acceleration/ejection time ratio (PATET) of the fetal main pulmonary artery Doppler waveform.MethodsWe prospectively studied pregnant women attending our hospital with confirmed SARS‐CoV‐2 infection by RT‐PCR test and an age‐matched control group who admitted for routine prenatal care. An ultrasound examination that included measurements of the AT, ET, and AT/ET ratio (PATET) were performed and the results were compared.ResultsFifty‐five SARS‐CoV‐2‐infected and 93 control group pregnant women were included in this study. AT found higher in the COVID‐19 positive group when compared with controls. When the ET and PATET parameters were compared, no differences were detected between the groups. Eleven neonates had Neonatal Intensive Care Unit (NICU) requirement in the COVID‐19 positive group while there were none in the control group. All fetal pulmonary artery Doppler values were decreased in NICU admitted fetuses. The mean gestational week of this group was lower than non‐NICU COVID‐19 positive group and the control group.ConclusionCOVID‐19 infection increases fetal pulmonary blood flow, which appears high AT values on Doppler parameters. NICU admission only occurred in the COVID‐19 group and their Doppler values were found significantly lower than non‐NICU COVID‐19 group. The clinical significance of this result must be evaluated with further studies.

Role of fetal main pulmonary artery doppler indices in prediction of fetal lung maturity

Background: Accurate evaluation of fetal lung maturity is of utmost importance for determining the optimal time for pregnancy termination. Amniocentesis is an invasive procedure and is associated with a small but real risk to the pregnancy. So noninvasive sonographic techniques to evaluate lung maturity is most needed. Objective: To study the role of fetal main pulmonary artery Doppler (MPA) indices in prediction of Fetal Lung Maturity (FLM) and determine a cut point of Doppler indices with high sensitivity and specificity. Patients and Methods: Our prospective cohort study included 200 pregnant women 38 weeks fulfilling the inclusion and exclusion criteria, A number of different parameters were measured from the fetal pulmonary artery flow (FPAF) waveform (At/Et, S/D, PSV, PI and RI) for diagnosis of neonatal Respiratory Distress Syndrome (RDS) by comparing the Doppler findings with the clinical outcome. Results: About 46 (23%) fetuses were diagnosed as RDS (+ve) and 154 (77%) fetuses were without RDS(-ve). At/Et and PSV were positively correlated, whereas PI and RI were inversely correlated with RDS. S/D ratio did not change significantly. The strongest correlation was found with At/Et. AT/ET was significantly lower in the RDS +ve group and cutoff point of 0.32 predicted the development of neonatal RDS with a high sensitivity specificity, and accuracy (98.0%, 92.0%, and 95.0% respectively). Conclusion: FLM and Neonatal RDS can be predicted using the MPA At/Et with high sensitivity and specificity.

The impact of betamethasone on fetal pulmonary, umbilical and middle cerebral artery Doppler velocimetry and its relationship with neonatal respiratory distress syndrome

BackgroundPrenatal corticosteroid administration is known to be an effective strategy in improving fetal pulmonary maturity. This study aimed to evaluate the impact of maternal betamethasone administration on fetal pulmonary and other arteries Doppler velocity and the correlation between RDS development and Doppler indices results.MethodsFifty one singleton pregnancies between 26 and 34 gestational weeks with a diagnosis of preterm labor were included in the exposed group and received betamethasone. Fifty one uncomplicated pregnancies were included in the non-exposed group. Fetal pulmonary, umbilical and middle cerebral arteries Doppler parameters were evaluated before and 24 to 48 h after steroid administration in the exposed group and two times at same intervals in the non-exposed group. Maternal records were matched to neonatal charts if delivery happened, and demographic and outcome data were abstracted.ResultsWhen compared with the nonexposed group, fetuses treated with corticosteroids demonstrated significantly decreased umbilical artery Pulsatility index (PI) and significantly increased the middle cerebral artery PI, pulmonary artery Acceleration time (AT) and pulmonary artery AT/ET (Ejection time), while all other indices remained similar. We found significantly decreased pulmonary artery AT in the fetuses with respiratory distress syndrome (RDS) compared to those that did not.ConclusionsThe results of our study showed that maternal antenatal betamethasone administration caused significant changes in the fetus blood velocity waveforms and also affected the blood flow in the pulmonary artery which led to an increase in the pulmonary artery AT and AT/ET. Among those fetuses with RDS, we found a significant decrease in the pulmonary artery AT, but we did not observe any pulmonary artery AT/ET differences.

427 Prenatal prediction of the fetal to neonatal cardiovascular transition

We sought to evaluate changes in the fetal pulmonary artery Doppler following maternal hyperoxygenation during the third trimester of pregnancy and correlate those findings with neonatal echocardiograph indices. Forty-six women with a singleton pregnancy ≥31weeks’ gestational age(GA) were prospectively recruited. Pulsatility index(PI),Resistance index(RI), acceleration time(AT) and ejection time(ET) were measured in the distal fetal pulmonary artery (PA). Doppler measurements were taken at baseline and following maternal hyperoxygenation(MH) for 10minutes.Reactivity to MH was considered where a decrease in PAPI was ≥10% from the baseline. Within 24hours of life a neonatal functional echocardiogram was performed to assess right ventricular systolic pressures,PAAT,ejection fraction(EF) and left ventricular cardiac output(LVCO). The median GA was 35weeks. There was a decrease in fetal PAPI and PARI and an increase in PAAT leading to an increase in AT:ET following MH (Table 1).Fetuses that responded to MH had an increased LVCO and EF. These findings were not dependent on LV size or mitral valve (MV) annular diameter but were related to an increased MV inflow.The PA reactivity was not associated with maternal age, BMI or GA at the time of MH (Table 2).The effect of MH on neonatal LVCO and EF was not dependent on mode of delivery or GA at delivery but on the prenatal response to MH. Maternal hyperoxygenation in the third trimester is associated with significant changes in fetal PA Doppler waveforms.An increased LVCO and EF in the neonates who responded to MH,suggests that MH may prove to be a more reliable predictor of postnatal cardio-pulmonary dysfunction compared to the prenatal evaluation of anatomic structures alone. The response to MH predicted neonatal LVCO suggesting that there is a cohort of infants who may be identified by MH,that may have an increased vulnerability to deal with neonatal illness, due to a limited ability to optimise LV preload. This warrants further exploration to establish the ability of MH to predict the neonatal cardiovascular transition.View Large Image Figure ViewerDownload Hi-res image Download (PPT)

Semi-Automated Graphical System for Calculating Pulmonary Vascular Impedances in a Clinical Setting

Goal: Create a semi-automated, graphical, stand-alone application that uses clinically available asynchronous pressure and Doppler velocity captures to rapidly calculate, display, and interpret the pulmonary vascular impedance (PVZ) spectra. Methods: MATLAB-based software was written to analyze PVZ by creating a composite PVZ (cPVZ) spectra comprised of asynchronous screen captures of pulmonary arterial pressure and pulmonary arterial pulsed-wave Doppler velocity waveforms obtained during standard of care procedures. The pressure waveform, Doppler frequency envelopes, and ECG signals were re-digitized via automated border detection. cPVZ of averaged representative beats was calculated in the frequency domain via Fast Fourier Transform, and plotted vs harmonic z. Results: Successful generation of impedance spectra (PVZ(z)), where z is the harmonic, and additional parameters for characteristic impedance (Zc) and stiffness (Zs) were calculated as the mean of PVZ(2-4), and the sum of PVZ (1, 2), respectively. Conclusions: A graphically driven analysis of PVZ, calculated from standard of care right heart catheterization and echocardiography is possible. This system can help characterize both the steady and pulsatile components of right ventricular (RV) afterload in the clinical setting.

Prenatal prediction of neonatal haemodynamic adaptation after maternal hyperoxygenation

The reactivity of the pulmonary vascular bed to the administration of oxygen is well established in the post-natal circulation. The vasoreactivity demonstrated by the fetal pulmonary artery Doppler waveform in response to maternal hyperoxia has been investigated. We sought to investigate the relationship between the reactivity of the fetal pulmonary arteries to hyperoxia and subsequent neonatal cardiac function in the early newborn period.MethodsThis explorative study with convenience sampling measured pulsatility index (PI), resistance index (RI), acceleration time (AT), and ejection time (ET) from the fetal distal branch pulmonary artery (PA) at baseline and following maternal hyperoxygenation (MH). Oxygen was administered for 10 min at a rate of 12 L/min via a partial non-rebreather mask. A neonatal functional echocardiogram was performed within the first 24 h of life to assess ejection fraction (EF), left ventricular output (LVO), and neonatal pulmonary artery AT (nPAAT). This study was conducted in the Rotunda Hospital, Dublin, Ireland.ResultsForty-six women with a singleton pregnancy greater than or equal to 31 weeks’ gestational age were prospectively recruited to the study. The median gestational age was 35 weeks. There was a decrease in fetal PAPI and PARI following MH and an increase in fetal PAAT, leading to an increase in PA AT:ET. Fetuses that responded to hyperoxygenation were more likely to have a higher LVO (135 ± 25 mL/kg/min vs 111 ± 21 mL/kg/min, p < 0.01) and EF (54 ± 9% vs 47 ± 7%,p = 0.03) in the early newborn period than those that did not respond to MH prenatally. These findings were not dependent on left ventricular size or mitral valve (MV) annular diameter but were related to an increased MV inflow. There was no difference in nPAAT.ConclusionThese findings indicate a reduction in fetal pulmonary vascular resistance (PVR) and an increase in pulmonary blood flow and left atrial return following MH. The fetal response to hyperoxia reflected an optimal adaptation to postnatal life with rapid reduction in PVR increasing measured cardiac output.

Relation Between Fetal Doppler Pulmonary Artery Indices and Neonatal Respiratory Distress Syndrome In Term Neonates

Background: Neonatal respiratory distress syndrome (RDS) is a common and challenging neonatal morbidity. Reliable prediction of the condition can improve management. Fetal pulmonary artery (PA) Doppler indices were suggested for prediction. However, the findings of different studies are conflicting.Aim of the work: The present study aimed to assess the value of PA indices in the prediction of neonatal RDS in term babies.Subjects and methods: This prospective study included 120 women with singleton term pregnancy. Assessed Doppler indices for the main pulmonary artery included pulsatility index (PI), resistive index (RI), peak systolic velocity (PSV), and the At/Et ratio. Upon delivery, the newborn babies were examined for RDS signs (tachypnea, retractions, and/or nasal flaring).Results: Among the 120 delivered babies, there were 16 (13.3 %) with RDS. Comparison between neonates with RDS and neonates without showed significantly lower neonatal weight, higher pulmonary artery RI and PI, higher pulmonary artery PSV in neonates with RSD. Also, they had a significantly lower pulmonary artery at/et ratio when compared with normal babies. The pulmonary artery at/et ratio showed the best performance compared to other indices (sensitivity: 100.0 %, specificity: 50.0 %) at a cut-off (0.32).Conclusions: The present study documented reliable predictive value of PA hemodynamic parameters including RI, PI, PSV, and at/et ratio in predicting neonatal RDS in term babies.

43 Pulmonary Artery dopplers for early prediction of Bronchopulmonary Dysplasia (BPD) in Extremely Low Birth Weight babies (ELBW): A forgotten tale

Abstract Introduction/Background BPD is a chronic lung disease that affects ELBW babies and contributes significantly to their morbidity and mortality. The early abnormal vasoreactivity observed in babies at risk of BPD increases the pulmonary vascular resistance and can be assessed non-invasively using Time to Peak Velocity: Right Ventricular Ejection Time ratio (TPV: RVET) that is calculated from pulmonary artery doppler waveform. We postulate that screening for this condition early may be useful to predict BPD in this cohort, which may provide prognostic information as well as early clinical management of the ELBW at risk of developing BPD and therefore can potentially present a window of opportunity for therapeutic intervention. Objectives 1. To determine utility of TPV/RVET ratio in predicting the risk for BPD in ELBW babies in a tertiary center. 2. To determine utility of TPV/RVET(c) ratio in predicting the risk for BPD in ELBW babies in a tertiary center. Design/Methods This is a retrospective cohort study of ELBW babies &amp;lt;29 weeks admitted to the Neonatal Intensive Care Unit at Stollery Children Hospital (SCH) over a 4 year time period and had early echocardiograms performed between 7-21 days of life. These babies were further identified to have BPD or no BPD at 36 weeks CGA. TPV/RVET ratios were measured by two reviewers from pulmonary artery doppler waveforms and were corrected for heart rate. The predictive ability of TPV/RVET and TPV/RVET(c) for subsequent development of BPD were analyzed using ROC curve. Inter observer agreement was evaluated. Logistic regression analysis was performed to derive a model that can be used in the 2nd to 3rd weeks of life, to predict the subsequent development of BPD at 36 weeks CGA. Infants with congenital heart disease (other than PDA, persistent foramen ovale/atrial septal defect and Ventricular Septal Defects), congenital lung malformations, multiple congenital anomalies and chromosomal anomalies were excluded. Results Out of 589 ELBW babies &amp;lt;29 weeks admitted to SCH NICU, 207 infants were eligible with early echocardiograms done at a mean age of 12.6 days (SD 4.1). One-hundred-and-twenty-five babies (60.4%) were found to have BPD. Babies with BPD were of lower gestational age (25.6 Vs 26.4, p-0.0001), sicker at birth (SNAPPE II 42.3 Vs 33.2, p-0.0024), had higher incidence of PDA needing surgical ligation (18.4% Vs 4.9%, p-0.005) and had spent more days on mechanical ventilation (39.8 Vs 12.5, p&amp;lt;0.0001) than those without BPD. Both TPV, TPV/RVET and its corrected ratios were significantly lower in ELBW babies with BPD compared to non-BPD babies (p&amp;lt;0.0001). The TPV/RVET ratio (cut off 0.34) and TPV/RVET(c) (cut off 0.54) had Sensitivities [76.8% (95%CI 68.4-83.9) and 72% (95%CI 63.3-79.7)], Specificities [85.4% (95%CI 75.8- 92.2) and 84.1% (95%CI 74.4-91.3)], Positive Predictive Values [88.9% (95%CI 81.4-94.1) and 87.4% (95%CI 79.4-93.1)], Negative Predictive values [70.7% (95%CI 60.7- 79) and 66.3% (95%CI 56.4-75.3)] and ROC area [0.811 (95% CI 0.757-0.864) and 0.781 (95% CI 0.725-0.837)] respectively. Multi variant logistic regression analysis showed Odds Ratio(OR) for having BPD at TPV/RVET cut off 0.34 and TPV/RVET(c) cut off 0.54 to be 19.9(95%CI 8.19-48.34) and 16.3(95% 6.78-39.33) respectively and the OR increased by 1.07(95%CI 1.05-1.09) and 1.08(95% CI 1.05-1.10) with every additional days of mechanical ventilation respectively. TPV/RVET ratio had 92.75% inter-observer agreement with kappa 0.83. Conclusion TPV/RVET and its corrected ratio are good and reliable early screening tools for subsequent development of BPD in ELBW babies with substantial inter-observer agreement. Two variable model namely TPV/RVET&amp;lt;0.34 and mechanical ventilation or TPV/RVET(c) &amp;lt;0.54 and mechanical ventilation can be used in the 2nd to 3rd week of life to predict subsequent development of BPD at 36 weeks CGA in ELBW babies.