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J P Youngblood

Publications and source records attributed to J P Youngblood.

11 recordsLinked to original sources
PubMed1993

A resident teaching program in operative endoscopy.

To provide a structured experience in operative endoscopy, a comprehensive teaching program has been incorporated into the obstetrics and gynecology residency program at our institution. This program consists of both a didactic and a hands-on portion. The hands-on session is conducted on a pelvic trainer. This approach to teaching residents operative endoscopy has been widely accepted by residents, faculty, and operating room personnel.

Female↗
PubMed1991

Comparative efficacy of umbilical arterial Doppler indices for predicting adverse perinatal outcome.

A variety of descriptor indices for the umbilical arterial Doppler waveform are currently in use for predicting perinatal outcome. However, there is a paucity of data regarding the relative diagnostic merits of these indices. We addressed this issue in a prospective, blind study in which the diagnostic efficacy of the following Doppler indices was compared: resistance index, systolic/diastolic ratio, pulsatility index, and diastolic average ratio. The analytic technique consisted of the receiver operating characteristic method, which evaluates a test's ability to discriminate a diseased from a healthy population. The patient population consisted of 350 pregnant patients with gestational ages of 34 to 36 weeks. A continuous-wave Doppler device with a 4 MHz transducer was used to investigate the umbilical vessels. The test was performed only once in each patient. The abnormal outcome parameters included small for gestational age (less than 10th percentile), Apgar score less than 7 at 5 minutes, fetal distress (late and severe variable decelerations, absent variability, fetal scalp pH less than 7.20), umbilical cord arterial pH less than 7.10, presence of thick meconium, and admission to neonatal intensive care unit (greater than 48 hours). The results showed that the resistance index had the best discriminatory ability when compared with other Doppler indices: the systolic/diastolic ratio (p less than 0.05), the pulsatility index (p less than 0.001), and the diastolic/average ratio (p less than 0.05). It is concluded that of the various Doppler indices assessed in this investigation, the resistance index offers the best diagnostic efficacy in predicting perinatal compromise.

Double-Blind Method↗
PubMed1990

The diagnostic efficacy of the umbilical arterial systolic/diastolic ratio as a screening tool: a prospective blinded study.

This prospective blinded study investigated the diagnostic efficacy of the umbilical arterial systolic/diastolic ratio performed at 34 to 36 weeks' gestation for identifying pregnancies at a high risk for adverse perinatal outcomes. A series of 350 consecutive singleton pregnancies were included in the study. A continuous-wave Doppler instrument with a 4 MHz transducer was used. The criteria for an abnormal perinatal outcome included intrauterine growth retardation, an Apgar score of less than 7 at 5 minutes, umbilical arterial pH at birth less than 7.20, presence of thick meconium, fetal distress in labor, and neonatal complications necessitating admission to the neonatal intensive care nursery. The analytic techniques included determination of the receiver operating characteristic curve, sensitivity, specificity, positive and negative predictive values, and the kappa index. The results demonstrated that although the cutoff value of 2.9 showed the maximum inherent discriminatory power, its diagnostic efficacy (sensitivity, 0.83; specificity, 0.87 positive predictive value, 0.74; negative predictive value, 0.92; and kappa index, 0.68) was not substantially different from that of the more common cutoff value of 3.0 (sensitivity, 0.79; specificity, 0.93; positive predictive value, 0.83; negative predictive value, 0.91; and kappa index, 0.73). Both values were rated good to excellent by the kappa index. The study also demonstrated that the systolic/diastolic ratio was a better predictor of general abnormal outcome than of the suboptimal fetal growth.

Blood Pressure↗
PubMed1989

Components of variability of umbilical arterial Doppler velocimetry--a prospective analysis.

This study prospectively analyzed the components of variance and error contributions of umbilical arterial Doppler indices in a normal pregnant population (308 women) with gestational ages ranging from 27 to 40 weeks. A continuous-wave Doppler instrument with a 4 MHz transducer was used. The Doppler indices measured were systolic/diastolic ratio, diastolic/average ratio, pulsatility index, and resistance index. The contributions of gestational age, fetal heart rate, location of measurement, interobserver variability, and intraobserver variability on the variance were studied. The investigation demonstrated that the gestational age and fetal heart rate contributed to 33% to 46% and 15% to 18% of the variance, respectively. The location of the Doppler measurement contributed to 29% to 46% of the error variance. Additionally, the interobserver and intraobserver error variance amounted to 10% to 14% and 5% to 9%, respectively. Of these various factors, the interobserver and intraobserver variance were related to the nonhemodynamic phenomena and therefore represented error components. It is obvious that these factors that affect the variance of the Doppler indices should be considered before the diagnostic reliability of this technique can be critically evaluated.

Analysis of Variance↗
PubMed1986

Doppler color flow mapping of the fetal heart.

The recently developed innovative technique of Doppler color flow mapping permits real time visualization of blood flow patterns superimposed on two-dimensional echocardiographic images of the heart. This study demonstrates, for the first time, the usefulness of this technique in characterizing fetal cardiac dynamics.

Blood Flow Velocity↗