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Biomedical subjects

G D Hankins

Publications and source records attributed to G D Hankins.

At least 19 recordsLinked to original sources

Cardiac disease and pregnancy.

The pregnant state imposes a supraphysiologic strain on the pregnant woman's cardiac performance through complex biochemical, electric, and physiologic changes affecting the blood volume, myocardial contractility, and resistance of the vascular bed. In the presence of underlying heart disease, these changes can compromise the woman's hemodynamic balance, her life, and that of her unborn child. Cardiac pathology represents a heterogeneous group of disorders, each with its own hemodynamic, genetic, obstetric, and social implications. Physicians caring for these women should actively address the issue of reproduction. Ideally, pregnancy should be planned to occur after optimization of cardiac performance by medical or surgical means. Once pregnancy is achieved, the concerted effort of a multidisciplinary team of obstetricians, cardiologists, anesthesiologists, nursing, social, and other services provides the best opportunity to carry the pregnancy to a successful outcome.

Algorithms↗

Teaching the Laufe-Piper forceps technique at cesarean delivery.

OBJECTIVE: To present a method of teaching forceps technique during cesarean delivery of breech-presenting infants using Laufe-Piper forceps and to evaluate its usefulness. STUDY DESIGN: For several years, residents at the University of Texas Medical Branch, Galveston, have learned and practiced Piper forceps technique during cesarean delivery. To assess their experience with this method, we mailed questionnaires to third- and fourth-year residents and recent graduates of the Galveston program. The same surveys were mailed to a control group of residents and recent graduates of two other programs where this teaching exercise is not practiced routinely. RESULTS: Responses were received from 32 (74%) study subjects and 63 (71%) controls. Demographic characteristics and experience with vaginal breech delivery were similar between the two groups. Respondents from the Galveston program noted greater annual use of forceps for vaginal delivery of cephalic-presenting infants (P = .012). They also rated themselves as more comfortable (P = .023) and more skilled (P = .006) with Piper forceps than controls. Of 53 respondents who had had previous experience with this teaching method, 47 noted that it provided a great or moderate educational benefit, and 36 strongly or moderately believed it gave them more confidence in using Piper forceps during vaginal breech delivery. Using multiple regression analysis, sex, overall level of experience, Piper forceps experience during vaginal delivery and overall forceps use were stronger determinants of self-rated comfort and skill than was experience with Laufe-Piper forceps during cesarean. CONCLUSION: Laufe-Piper forceps can be used for cesarean delivery of breech-presenting infants. This practice promotes confidence and skill for their use at vaginal delivery.

Breech Presentation↗

Prospective study of IgM to Toxoplasma gondii on Beckman Coulter's Access(TM) immunoassay system and comparison with Zeus ELISA and gull IFA assays.

We compared a new assay for Toxoplasma IgM on the Access analyzer (Beckman Coulter, Inc., Chaska, MN, USA), a random access instrument based on the principle of paramagnetic particle enzyme immunoassay with an enzyme-linked immunosorbent assay (ELISA) (Zeus Scientific, Inc., Raritan, NJ, USA) and an immunofluorescent assay (IFA) (Gull Laboratories, Inc., Salt Lake City, UT, USA). Four hundred fresh, unfrozen clinical samples from pregnant women (n = 154), HIV positive patients (n = 41), and patients in whom infection with Toxoplasma gondii was suspected (n = 200) were collected and assayed over a three month period. The specificity of the Access assay was compared to the consensus results. Results that were discrepant between the ELISA and IFA were resolved using a third IFA (Zeus). Once resolved, the specificity for the Access assay, the Zeus ELISA and the Gull IFA were 99.22%, 97.91%, and 99.45%, respectively. We conclude that the Access assay specificity is comparable to consensus results, minimizing false positive results; and because it is a random access instrument, it may be preferable over batch methods.

Adolescent↗

Embryonic hemoglobins are expressed in definitive cells.

Human embryonic zeta and epsilon globin chains are synthesized in yolk sac-derived primitive erythroid cells, and decrease rapidly during definitive erythropoiesis. Examination of zeta and epsilon globin expression at the cellular level using dual-color immunofluorescence staining with specific monoclonal antibodies showed that embryonic globin proteins are present in definitive erythroid cells. More than half of fetal erythrocytes were positive for zeta and approximately 5% for epsilon globin. Approximately one third of newborn red blood cells were zeta-positive and less than 1% epsilon-positive. Adult erythrocytes did not have embryonic globins. Erythroblasts that developed in liquid cultures also contained embryonic globin in amounts which declined with ontogenic age, and the proportion of positive cells in vitro was less than in the comparable erythrocytes that developed in vivo. Thus, embryonic globin chains are synthesized in definitive erythroid cells and decrease with ontogeny. Modulation of embryonic globin gene expression is not solely due to a switch from primitive to definitive erythropoiesis.

Adult↗

The role of forceps rotation in maternal and neonatal injury.

OBJECTIVE: Our purpose was to assess the impact of forceps rotation on maternal and neonatal injury. STUDY DESIGN: In this retrospective case-controlled study performed at the University of Texas Medical Branch at Galveston all forceps deliveries with a rotation of >/=90 degrees performed between July 1992 and September 1995 were identified (n = 113). For controls 167 forceps deliveries with rotations of </=45 degrees were randomly selected. Control deliveries occurred during the same time period and were matched to within 2 weeks of gestational age as well as to nulliparous versus parous status. The majority of deliveries were low; however, some midforceps deliveries were also included. RESULTS: Forceps rotations of >/=90 degrees accounted for 0.8% of all deliveries. A major fetal injury, defined as a skull fracture, subdural hematoma, brachial plexus or a sixth or seventh cranial nerve injury, occurred in 10.2% of deliveries with rotations of </=45 degrees and in 9.7% with rotations of >/=90 degrees. The only permanent injury was a brachial plexus palsy that occurred with a forceps rotation of 45 degrees. Rotations of >/=90 degrees were not associated with umbilical arterial acidemia below 7.0 or 7.1 compared with rotations of </=45 degrees. Rotations of >/=90 degrees were associated with longer maternal hospital stays (P =.009). Neither lacerations of the birth canal, third- or fourth-degree episiotomies, or fall in the maternal hematocrit correlated with the degree of forceps rotation. CONCLUSIONS: Advanced degrees of forceps rotations do not result in any clinically significant increase in infant or maternal morbidity relative to that encountered with lesser degrees of forceps rotation.

Birth Injuries↗

Maternal oxygen transport variables during the third trimester of normal pregnancy.

OBJECTIVE: The aim of this study was to measure and calculate oxygen transport variables in uncomplicated term pregnancies. STUDY DESIGN: Ten normotensive primiparous women between 36 and 38 weeks' gestation underwent pulmonary and radial arterial catheterization as part of a larger study. Seven women had studies repeated at approximately 12 weeks post partum. Measurements were made with patients in the left lateral recumbent position after a 30-minute stabilization period. Cardiac output was measured with the thermodilution technique. Blood samples were obtained simultaneously from the pulmonary and radial arteries and analyzed in duplicate for oxygen content with a blood gas analyzer. RESULTS: The oxygen contents of both arterial and mixed venous blood are significantly lower (P <.05) in the third trimester of pregnancy (15.96 and 11.97 mL/dL, respectively) than in the postpartum period (18.00 and 13.54 mL/dL). The fall in oxygen content during pregnancy prevents any significant increase in oxygen delivery in the third trimester (867. 59 mL/min) relative to the postpartum period (806.50 mL/min, P not significant). CONCLUSION: This is the first report of directly measured oxygen transport variables in healthy pregnant women.

Biological Transport↗

The effect of amniotic fluid on the human omental artery in vitro.

OBJECTIVE: The aim of the study was to determine the effect of amniotic fluid on the in vitro contractility of the human omental artery. STUDY DESIGN: Amniotic fluid and a segment of omentum were obtained from each of 5 patients at the time of planned cesarean delivery at normal term gestation for the indication of previous cesarean delivery. The omental artery was cleaned and cut into 3-mm rings, which were placed in 10-mL organ chambers for isometric tension recording. The chambers were filled with Krebs-Henseleit solution bubbled with 5% carbon dioxide in air and maintained at 37 C, pH 7.4. The rings were then equilibrated at 1 g passive tension for 90 minutes. The amniotic fluid was centrifuged for 10 minutes at 3000 rpm to remove all debris. Increasing volumes of supernatant (10-2000 microL) were added to the omental artery rings at baseline tone or after contraction with U46619 (10(-7) mol/L) or potassium chloride (60 mmol/L) to detect contractile and relaxant effects, respectively. Time-solvent control preparations were also run in parallel. RESULTS: Amniotic fluid had no effect on the basal tone of omental artery rings. Amniotic fluid had no effect on the tension in rings previously contracted with either U46619 or potassium chloride. CONCLUSIONS: Amniotic fluid has no direct effect on isolated human omental artery. The catastrophic hemodynamic changes associated with the syndrome of amniotic fluid embolism are not due to a direct effect of circulating amniotic fluid on vascular tone but rather may be due to secondary responses

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗

Forceps and vacuum delivery: expectations of residency and fellowship training program directors.

The objective of this study is to compare current forceps training practices in North American obstetrical residency training programs with that in maternal-fetal medicine fellowship programs. We sent a survey to all obstetrics and gynecology residency training programs and to all maternal-fetal medicine fellowship programs in North America. After sending out 354 questionnaires, 219 were returned for a response rate of 62%. The response rate for fellowship programs (52 of 59; 88%) was significantly greater than that of residency training programs (167 of 295; 56.6%) (p < 0.05). All fellowship training programs were using the 1988 ACOG forceps classification system, as were 98% of the residency training programs. Eighty-five percent of fellowship directors and 80% of residency directors felt the same system should be used for vacuum deliveries. All residency and fellowship directors expected proficiency with both instruments for outlet deliveries. For low deliveries requiring < or =45 degrees of rotation, at least 92% expected proficiency with both instruments. For low-forceps deliveries with >45 degrees of rotation, 82% of fellowship directors and 80% of residency directors expected proficiency. For low-vacuum deliveries with >45 degrees of rotation, 80% of fellowship directors and 76% of residency directors expected proficiency. Significantly more fellowship directors expected midforceps proficiency (47%) than did residency program directors (38%) (p < 0.05). Midvacuum proficiency was expected by 73% of fellowship directors and 69% of residency directors. The ACOG 1988 forceps classification system has now achieved wide acceptance and is taught by both residency and fellowship program directors. Most program directors favor using the same classification system for vacuum extraction deliveries. In general, the expectations of the residency program directors mirror those of maternal-fetal medicine fellowship directors. While outlet and low operations with < or =45 degrees of rotation are taught and proficiency is expected, most programs no longer expect proficiency in midforceps delivery, but do expect proficiency in midvacuum delivery. Proficiency in low operations with rotations < or =45 degrees is still expected.

Adult↗

Electronic fetal monitoring. Are we meeting documentation standards?

OBJECTIVE: To test whether fetal heart rate documentation requirements for high-risk pregnancies are too stringent to achieve compliance, especially during the second stage of labor. STUDY DESIGN: Random retrospective chart and monitor strip review of deliveries occurring one year earlier were reviewed. Thirty-four low-risk and 34 high-risk pregnancies were selected and assessed for compliance with nationally accepted documentation guidelines. RESULTS: All monitor strips and charts were successfully retrieved from medical records. Charted documentation of the strips met national requirements in the active phase of the first stage of labor in 97% of cases, as did documentation during the second stage. For high-risk pregnancies, compliance during the active phase of the first stage of labor was 65% as compared to 35% in the second stage. All infants had normal five-minute Apgar scores, and none had umbilical arterial acidemia. CONCLUSION: Given current resources, we cannot reliably meet established documentation standards for high-risk pregnancies. Such overly stringent documentation standards pose a significant risk in cases going to litigation. A standard should be developed that is based on outcome data.

Adult↗

Prevalence and risk factors of chorioamnionitis among adolescents.

OBJECTIVE: To identify the prevalence of chorioaminionitis and unique risk factors for this disorder among adolescents under 18 years of age. METHODS: At their first prenatal visit we interviewed 352 adolescents who received prenatal care and delivered an infant at our institution between April 20, 1992, and November 10, 1994, to elicit information on demographic characteristics and behavioral risk factors. Retrospective chart review confirmed the presence of chorioamnionitis using accepted clinical criteria. We determined reproductive history, evidence of sexually transmitted disease, duration of labor, use of oxytocin, an internal uterine pressure monitor or conduction anesthesia, timing and duration of ruptured membranes, type of delivery, and infant birth weight from review of subjects' charts. Logistic regression analysis was used to develop adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for risk factors of chorioaminionitis. RESULTS: Ten percent (34 of 352) of adolescents met the clinical definition for chorioamnionitis. Alcohol and tobacco use during pregnancy (OR 7.6; 95% CI 2.3, 25.8) and being married or living with a partner (OR 2.7; 95% CI 1.1, 6.5) were significantly associated with chorioamnionitis, as was conduction anesthesia (OR 4.1; 95% CI 1.1, 15.4), a second stage labor longer than 2 hours (OR 3.5; 95% CI 1.4, 8.5), and rupture of the membranes longer than 18 hours (OR 6.9; 95% CI 2.5, 18.9). Parity or preterm delivery did not differ significantly between those with or without chorioamnionitis. CONCLUSION: These data suggest that in addition to risk factors observed in adults, adolescents who concurrently use tobacco and alcohol during pregnancy, are married or living with a male partner, and have conduction anesthesia are at increased risk for chorioamnionitis.

Adolescent↗

Lower thoracic spinal cord injury--a severe complication of shoulder dystocia.

Fundal pressure as a maneuver for the relief of shoulder dystocia is associated with up to a 77% fetal injury rate. The usual injuries involve the brachial plexus or orthopedic injuries. We now report a severe lower thoracic spinal cord injury with permanent neurological injury when fundal pressure was applied in an attempt to relieve shoulder dystocia. Shoulder dystocia occurred in a 28-year-old nulliparous woman. A series of manual maneuvers to include episiotomy extension, McRoberts, suprapubic pressure, Woods screw, and extraction of the posterior arm all failed to achieve delivery. During these maneuvers, but not coordinated with them, fundal pressure was applied by multiple individuals. The Zavanelli maneuver and cesarean delivery ultimately allowed delivery. On Day 2 of life marked decrease in lower extremity motor function, over-flow urinary incontinence, and rectal incontinence led to imaging studies that revealed focal spinal cord injury at T-9 through T-12. Compressive forces applied to the fetal spine during fundal pressure is the likely cause of the lower thoracic spinal cord injury manifest by this newborn.

Adult↗

Amniotic fluid embolism in progress: a management dilemma!

Amniotic fluid (AF) embolism is a rare but catastrophic complication of pregnancy. We present the first case where the debris was seen in the maternal uterine veins at the time of cesarean section. During a cesarean delivery performed for deteriorating fetal status and in conjunction with massive hydramnios; air bubbles and vernix were observed in the left uterine vein and in an area of Couvelaire appearance of the uterine fundus. As the patient was clinically stable and desired retained fertility, a decision was made to attempt to contain the debris in the uterine vasculature. The infundibulopelvic ligament and uterine arteries were ligated and the area of Couvelaire uterus was oversewn. With the exception of a mild laboratory coagulopathy, which required no specific treatment, the patient did well. The area of Couvelaire uterus is the likely portal for the debris seen in this patient's vasculature. Containment appears to have averted the AF embolism syndrome.

Adult↗

Aeromedical transfer of preterm labor patients.

Obstetric patients are transported by air quite frequently. We evaluated transport times, obstetric outcomes, air-versus-ground transport costs, and related data on 22 helicopter aeromedical transports of pregnant patients with preterm labor. We found no significant differences between patients who delivered and those who did not when comparing transport time (167.1 +/- 41.9 minutes versus 177.1 +/- 56.2 minutes), air distance of transport (122.9 +/- 44.8 miles versus 143.6 +/- 23.8 miles), and other outcome measures. No deliveries occurred in flight. Air transport costs were significantly greater than estimated ground transfer ($4613.64 +/- $581.12 versus $604.02 +/- $306.38; P < .01). Two-way air transfer of preterm labor patients over moderate distances is more costly than contracted ground transfer costs at our institution.

Air Ambulances↗

Prolonged fetal bradycardia secondary to maternal hypothermia in response to urosepsis.

Fetal bradycardia is a well-known response to maternal hypothermia, as induced at open-heart surgery, but heretofore has not been reported in conjunction with hypothermia from urosepsis. A 24-year-old Vietnamese woman admitted at 33 weeks estimated gestational age with pyelonephritis secondary to Escherichia coli developed several episodes of maternal hypothermia to 35-36 degrees C. During each episode of maternal hypothermia, the baseline fetal heart rate fell to 90-100 bpm, but with retained reactivity. During each episode, maternal vital signs were otherwise stable and oxygen saturation was normal as measured by pulse oximetry. Interpretation of fetal bradycardia during episodes of maternal urosepsis is complex. If seen in conjunction with maternal hypothermia, and in the presence of normal maternal cardiac and respiratory function, bradycardia is unlikely to represent fetal distress.

Adult↗

Third-trimester arterial blood gas and acid base values in normal pregnancy at moderate altitude.

OBJECTIVE: To report arterial blood gas and acid base values of normal nulliparous patients at moderate altitude for commonly used maternal positions. METHODS: Ten normotensive nulliparous women between 36 and 38 weeks' gestation volunteered to undergo radial and pulmonary artery cannulation as part of a larger study. Following instrumentation, baseline assessments were made in the left lateral recumbent position after a 30-minute stabilization period. Sequential measurements were then obtained in the left lateral, right lateral, supine, knee-chest, sitting, and standing positions. Blood samples were analyzed in duplicate for oxygen content on a blood gas analyzer. Statistical analysis was performed by analysis of variance of repeated measures with significance defined at P < or = .05. RESULTS: There was no significant difference in arterial blood gas or acid base values between any positions in this antepartum population of term healthy women. The composite mean values were as follows: pH 7.46, arterial carbon dioxide pressure (PaCO2) 26.6 mmHg, arterial oxygen pressure 88.3 mmHg, bicarbonate 18.2 mEq/L, saturated arterial hemoglobin level 0.96. CONCLUSION: Arterial blood gas and acid base values are not altered by maternal position in the late third trimester of pregnancy. The PaO2 in these women studied at moderate altitude was lower than previously reported for healthy pregnant women studied at sea level. Appropriate interpretation of arterial blood specimens of pregnant women should take into account both the pregnancy and altitude at which the women reside.

Acid-Base Equilibrium↗

The effects of maternal position and cardiac output on intrapulmonary shunt in normal third-trimester pregnancy.

OBJECTIVE: To assess the effect of pregnancy, maternal position, and cardiac output on intrapulmonary shunting (Qs/Qt) in normotensive nulliparous women near term. METHODS: Ten normotensive nulliparas between 36 and 38 weeks' gestation underwent pulmonary artery catheterization (via the subclavian route) and radial artery canalization. Baseline assessments were made with subjects in the left lateral recumbent position after a 30-minute stabilization period. Measurements were obtained sequentially in the left lateral, right lateral, supine, knee-chest, sitting, and standing positions. Each position change was followed by a 10-minute pre-measurement stabilization period. Cardiac output was measured via the thermodilution technique. Blood samples were obtained simultaneously from the pulmonary and radial arteries and analyzed in duplicate for oxygen content with a blood gas analyzer. Qs/Qt was calculated using the classic shunt equation. Statistical analysis was performed by analysis of variance of repeated measures of Qs/Qt and maternal position. The relationship of Qs/Qt to maternal cardiac output was evaluated by the correlation coefficient. Significance was defined as P < .05. RESULTS: Directly measured Qs/Qt averaged 15.3% in left lateral, 15.2% in right lateral, 13.9% in supine, 12.8% in knee-chest, 13.8% in sitting, and 13.0% in standing positions. There was no statistically significant correlation between Qs/Qt and cardiac output (R2 = 0.11, not significant). CONCLUSION: This is the first report of directly measured Qs/Qt in normal pregnant women in the third trimester. Qs/Qt values reported in pregnancy are higher than those reported in nonpregnant individuals.

Adult↗

Operative vaginal delivery--year 2000.

Literature review was performed to analyze and define the current state of operative vaginal delivery. On the basis of published data, it is concluded that outlet and low forceps deliveries with < or = 45 degrees of rotation are effective and safe for both mother and baby. The greatest risk to mother or fetus occurs with operations performed at the 0 or +1 station or those involving rotations > 45 degrees. It is likely that operative deliveries involving > 45 degrees of rotation will be abandoned in the future. It is further recommended that The American College of Obstetricians and Gynecologists 1988 forceps classification system be adopted for deliveries by vacuum extractors.

Delivery, Obstetric↗