Search PubMed⌕ Search

Biomedical subjects

R A Knuppel

Publications and source records attributed to R A Knuppel.

At least 19 recordsLinked to original sources
PubMed1992

Evaluation of oxygen desaturation events in singleton pregnancies.

Previous investigators have demonstrated that oxygen desaturation may occur in laboring women. The purposes of this study were to identify groups at risk for desaturation and to seek correlation with newborn outcome. Volunteers in labor were evaluated for oxygen desaturation, analgesic exposure, magnesium sulfate administration, and various medical illnesses. Desaturations were noted more frequently in women exposed to narcotic analgesics, sedatives, and magnesium sulfate. A trend toward more desaturations in the women with preeclampsia was noted. Although desaturations related to narcotic analgesics and sedatives are most likely due to hypoventilation, the mechanism in women treated with magnesium sulfate is uncertain. Maternal peripartum desaturations did not result in unfavorable neonatal Apgar scores, cord blood gas measurements, or neonatal oxygen desaturation values, but the staff was aware of the events and prompt treatment was instituted.

Apgar Score↗
PubMed1991

Peritoneal closure or non-closure at cesarean.

The value of peritoneal closure at the time of cesarean birth was evaluated prospectively. Two hundred forty-eight women undergoing low transverse cesarean through a Pfannenstiel skin incision were assigned to one of two groups: peritoneum open (N = 127) or peritoneum closed (N = 121). The mean (+/- SEM) surgical time in the open group (48.1 +/- 1.2 minutes) was significantly less than for the closed group (53.2 +/- 1.4 minutes) (P less than .005). There were no postoperative differences between the groups in the incidence of wound infection, dehiscence, endometritis, ileus, and length of hospital stay. Our study suggests that leaving the parietal peritoneum unsutured is an acceptable way to manage patients at cesarean delivery.

Adult↗
PubMed1991

Finapres: a noninvasive device to monitor blood pressure.

Often, obstetric patients are not evaluated in preliminary studies during the development of new medical devices. The purpose of this study was to compare the Finapres digital probe with oscillometric and arterial line devices for recording blood pressures in low- and high-risk pregnant women. A total of 38 women were studied, including 24 with pregnancy-induced hypertension, two with chronic hypertension, two with cardiac disease, and ten who had no risk factors but requested epidural catheter placement. The comparison of Finapres or oscillometric recordings with direct arterial values confirmed that systolic recordings were imprecise for both devices (r = 0.80 and r = 0.64, respectively). Diastolic recordings (Korotkoff sound, phase 4) from the Finapres were accurate compared with the arterial values (r = 0.84). The Finapres performed at least as reliably as the oscillometric monitor in assessing blood pressure in our pregnant population and provided continuous measurements. When very accurate systolic recordings are needed, arterial catheter placement may be necessary.

Adult↗
PubMed1991

Cervical cerclage in early pregnancy.

A retrospective review of 33 patients who underwent transvaginal cervical cerclage for the treatment of an incompetent cervix from June 1984 through July 1987 was conducted. A total of 38 transvaginal cerclages were placed. For the purposes of comparison, the patients were divided into three groups according to gestational age at the time of cerclage: group 1 less than or equal to 13 weeks; group 2 greater than 13 weeks, but less than 18 weeks; group 3 greater than or equal to 18 weeks. There was no difference among groups in mean age, gravidity, history of diethylstilbestrol exposure (DES), prior pregnancy loss at or before 20 weeks, or prior dilation and curettage procedure. There were 24 modified McDonald and 14 modified Shrodkar procedures performed. The mean gestational age of cerclage placement in group 1 was earlier than in group 2 and group 3 by 3.5 and 10.5 weeks, respectively. There were no major surgical complications in any of the three groups. The overall incidence of preterm labor and preterm birth were 48.6% and 37.8%, respectively. Analysis of variance demonstrated a trend toward differences in the incidence of preterm labor, preterm birth, and estimated gestational age at delivery, with the earlier group favored. None of these, however, reached the level of statistical significance. Estimated blood loss, obstetric complications, mean birthweight, and mean gestational age at delivery were not statistically different for the three study groups. The above data are discussed and support given for the safety and efficacy of cervical cerclage placement in early pregnancy when compared with the more standard recommendations of placement at from 14 to 17 weeks' gestational age.

Adult↗
PubMed1991

A randomized comparison of assisted vaginal delivery by obstetric forceps and polyethylene vacuum cup.

The assisted vaginal delivery methods of rigid obstetric forceps and polyethylene vacuum cup extraction were compared in a prospective, randomized study. The 99 women studied had all completed 35 full weeks' gestation, required attempted assisted vaginal delivery, and were randomly assigned to either attempted forceps or vacuum-assisted delivery. All presentations were cephalic, with stations ranging from +1 to +4. Neonates were evaluated at 24 hours by neonatal staff. The infants underwent intracranial ultrasound screening during the first 24 hours of life and ophthalmologic examination within 48 hours. Vaginal delivery was successful with the intended method in 83% of vacuum-assisted deliveries and in 78% of forceps deliveries (not statistically significant). Neonatal retinal hemorrhage was found in 17 and 38% (P less than .043) of the randomized forceps and vacuum deliveries, respectively. No intraventricular hemorrhage was found. Apart from associations between vacuum-assisted delivery and mild hyperbilirubinemia and neonatal retinal hemorrhage (of uncertain clinical significance), and between assisted forceps delivery and an increased potential for facial injury, neonatal outcomes did not differ significantly. Maternal outcomes also did not differ significantly. No significant differences in safety or efficacy were found between polyethylene cup vacuum extraction and rigid obstetric forceps-assisted vaginal delivery in this population of predominantly low-pelvic assisted deliveries. Patients delivered by sequential use of forceps after vacuum or by vacuum after failed forceps application did not suffer significantly increased morbidity relative to those delivered by forceps or vacuum alone. Use of alternate or sequential methods allowed an overall cesarean rate of 3% in this population.

Acid-Base Equilibrium↗
PubMed1991

Perinatal outcome following improvement of abnormal umbilical artery velocimetry.

Umbilical artery velocimetry was investigated to determine whether abnormal flow patterns improved with bed rest and if the prognosis of the pregnancy was different in the improved groups. Abnormal flow waveform was defined as a systolic-diastolic ratio (S/D) above the 95th percentile of established normal values. One hundred twenty-eight women had abnormal waveforms. They were placed on bed rest in the left lateral position and monitored by biophysical profile and growth indices. Sixty-six subjects (51.5%) reverted to normal flow waveforms following bed rest, at a mean (+/- SD) interval of 4.5 +/- 1.5 weeks (range 3-10), and 62 (48.5%) exhibited persistent abnormal flow. None of the improved group exhibited fetal distress or perinatal mortality, whereas in the group with persistent abnormal flow, 15 (24%) experienced fetal distress and 13% experienced perinatal mortality. The diagnosis-to-delivery interval in the improved group was 63 +/- 14 days, versus 26 +/- 21 days in the unimproved group, and the mean gestational age at delivery was 37.3 +/- 2.0 versus 32.8 +/- 3.6 weeks, respectively (P less than .0001). We conclude that a subset of patients with abnormal Doppler velocimetry findings will improve on bed rest and have a better perinatal outcome, whereas persistence of abnormal flow defines a group of patients who are at risk for poor perinatal outcome and who require intensive monitoring and intervention.

Bed Rest↗
PubMed1991

Shoulder dystocia.

Shoulder entrapment during delivery is a true obstetric emergency that can result in significant maternal and infant trauma. Fetal macrosomia, maternal obesity, maternal diabetes and prolonged second stage of labor are associated risk factors. Infant complications of shoulder dystocia include traumatic brachial plexus injury, humeral fracture, clavicular fracture and severe birth asphyxia. With fetal shoulder entrapment, the mother may have significant hemorrhage, fourth-degree perineal lacerations and endometritis. Maneuvers to release the shoulder include closed-fist suprapubic pressure, downward pressure on the posterior shoulder, rotation of the anterior shoulder to the oblique position, rotation of the posterior shoulder beneath the pubic symphysis, release of the posterior arm and anterior rotation of the fetal body.

Delivery, Obstetric↗
PubMed1991

Alcohol use in pregnancy.

The epitome of FAS and ARBD has been documented substantially in the medical literature. There appears to be little question that alcohol is a teratogen. The precise nature for the mechanism of causing congenital defects, whether it be direct or indirect, is still unknown. There is no unequivocal information that can be conveyed to patients regarding the quantity of alcohol that can be safely consumed during pregnancy. Because pregnant women generally are receptive to suggestions about controlling their alcohol consumption during pregnancy, the professional is presented with an excellent opportunity to encourage behavior modification. Early recognition of the alcohol-abusing women and appropriate counseling are the cornerstones of treatment for these patients.

Abnormalities, Drug-Induced↗
PubMed1990

The value of early third-trimester maternal serum alpha-fetoprotein determination.

The value of determination of maternal serum of alpha-fetoprotein (MSAFP) concentration in the second trimester is well established. In addition to open neural tube defects, pregnancies associated with elevated second-trimester MSAFP have been shown to be at increased risk for a variety of problems, including low birth weight, preterm delivery, and pregnancy-induced hypertension (PIH). We evaluated the potential usefulness of MSAFP in the early third trimester. MSAFP concentration was determined in over 200 women at the time of glucose screening. Results were analysed with regard to gestational age at sampling, maternal weight, race, diabetes, and presence of twins. MSAFP was twice as high in twin gestation, but not affected by race or the presence of diabetes. In contrast to levels in early gestation, third-trimester MSAFP does not appear to be predictive of preterm delivery, low birth weight, or PIH.

Female↗
PubMed1990

Potential prenatal predictions of Down syndrome: a statistical analysis.

To determine the feasibility of combining several screening tests for the prenatal detection of Down syndrome, we evaluated the potential relationship among three proposed predictors. We determined the concentration of chorionic gonadotropin in frozen serum samples from women of known maternal age and weight, fetal biparietal diameter, and femur length, and alpha-fetoprotein concentration. When corrected for gestational age and maternal weight, the potential predictors were independent, except for a slight correlation (r = 0.10) between maternal serum alpha-fetoprotein and maternal serum human chorionic gonadotropin. Both maternal serum human chorionic gonadotropin and biparietal diameter/femur length demonstrated an approximately log-normal distribution similar to maternal serum alpha-fetoprotein. Therefore it is scientifically sound to use any or all of these variables in combination for the identification of pregnancies at increased risk for Down syndrome.

Body Weight↗
PubMed1990

Amniotic fluid alpha 1-antitrypsin concentration in premature rupture of the membranes.

Premature rupture of the membranes is probably a result of a loss in amniotic membrane collagen. A recent report that the concentration of alpha 1-antitrypsin was decreased in patients with premature rupture of the membranes suggested a generalized defect in such pregnancies. In this study we compared the concentration of alpha 1-antitrypsin in samples from pregnancies with premature rupture of the membranes and from pregnancies with preterm labor at similar gestational age. No difference in alpha 1-antitrypsin concentration was noted between these groups or between samples with or without intrauterine infection. These results support a localized inflammation and necrosis of the membranes at the site of rupture.

Amniotic Fluid↗
PubMed1990

The effect of magnesium sulfate infusion on systemic and renal prostacyclin production.

Recent in vitro studies have suggested that magnesium sulfate (MgSO4) infusions may increase prostacyclin production. We studied the effect of MgSO4 infusion on prostacyclin (PGI2) metabolite excretion in women with either pregnancy induced hypertension or preterm labor. Excretion of renal and systemic metabolites of PGI2 was measured prior to and following the start of MgSO4 infusion in the two groups. An increased in renal PGI2 metabolite preterm labor excretion was noted in the hypertension group but no change was noted in systemic PGI2 excretion in either group. These data fail to support a generalized, short term increase in endothelial cell PGI2 production as the basis for the beneficial effect of MgSO4.

Adult↗
PubMed1990

Antenatal fetal diagnosis and maternal transport gastroschisis. A maternal-infant case report.

Gastroschisis is a rare congenital birth defect of the abdominal wall that invariably is fatal if not managed appropriately. Early in utero diagnosis is now possible using maternal serum alpha-fetoprotein and ultrasound. As with other serious congenital disorders, antenatal diagnosis allows therapeutic options and time for preparation. Even if the diagnosis is made late, however, efforts to achieve prenatal maternal transport are still reasonable. The neonatal outcome of an unplanned delivery of an anomalous child requiring immediate attention is likely to be better if the delivery occurs in a tertiary center. These facilities generally have specialized services and teams available for critical care around the clock. The authors describe the maternal transport and delivery of a neonate with a serious disorder that required specialized attention at an hour when most hospitals are staffed with a skeleton crew. The necessary resources were available immediately, and the neonatal outcome was favorable. Although this report describes gastroschisis specifically, the concept of tertiary site delivery for potentially seriously ill neonates applies to any condition. With a late diagnosis, possible other anomalies, and a logistically unfavorable hour, the advantages of maternal transport are evident. This report also briefly reviews the area of antenatal ultrasound diagnosis and the newer mechanisms used to develop a perinatal care plan.

Abdominal Muscles↗
PubMed1990

Acute pyelonephritis in pregnancy: a prospective study of oral versus intravenous antibiotic therapy.

Ninety pregnant women admitted to the high-risk pregnancy unit with a diagnosis of acute pyelonephritis were randomized to receive either oral (cephalexin 500 mg every 6 hours) or intravenous (IV) (cephalothin 1 g every 6 hours) antibiotic therapy. All patients were initially hydrated with 1 L of normal saline IV over 4 hours. Neither parenteral analgesics nor antiemetics were used. Bacteremia was noted in 13 (14.4%) of the 90 patients and mandated IV therapy. There was no difference between the oral and IV groups concerning predefined criteria for successful therapy (91.4 versus 92.9% successful therapy, respectively). No characteristic available at presentation predicted bacteremia or ultimate failure of therapy. Two patients (2.2%) experienced significant complications. These data suggest that in nonbacteremic patients, oral antibiotics are both safe and effective for the treatment of acute pyelonephritis in pregnancy.

Acute Disease↗
PubMed1990

Uterine activity compared with symptomatology in the detection of preterm labor.

The relative contribution of uterine activity obtained by home monitoring with a guard ring tocodynamometer compared with seven specific signs and symptoms reported during patient/nurse contact as an aid in detecting preterm labor has not been studied. In this prospective, multicenter study, patients at risk for developing early labor who were randomized to receive home uterine activity monitoring and perinatal nursing support were assessed. The initiator of provider contact (uterine activity detected on routine transmission, patient-perceived signs and symptoms of preterm labor during perinatal nurse contact, or both) resulting in a diagnosis of preterm labor was recorded. Contraction data were then analyzed for an association with preterm labor. There was a strong association of increased uterine activity (four or more contractions per hour) on a repeat monitoring strip with preterm labor (P less than .001). Among patients diagnosed with preterm labor, 31% had increased uterine activity detected on a routine transmission without patient-reported signs and symptoms, compared with 24% who were diagnosed as the result of patient-reported symptoms without increased uterine activity. Daily objective uterine activity data alone have greater incremental value over and above other signs and symptoms as an aid to the physician in diagnosing preterm labor.

Female↗
PubMed1990

The contribution of symptomatology and/or uterine activity to the incidence of unscheduled visits.

Home uterine activity monitoring and perinatal nursing support have been shown to be associated with a decrease in preterm births with no increase in the number of unscheduled patient visits. This prospective, randomized multicenter study compared the frequency of unscheduled visits in patients receiving home uterine activity monitoring and perinatal nursing support with that of patients receiving education regarding the detection and reporting of preterm labor symptomatology. The contribution of patient-reported signs and symptoms versus objective uterine activity data to unscheduled visits is assessed. The overall frequency of unscheduled visits was similar in both groups. In the home uterine activity monitoring and perinatal nursing support group, the contributions of uterine activity versus signs and symptoms to the diagnosis of preterm labor were equal, with 36% of patients diagnosed with preterm labor sent to the physician for increased uterine activity and 36% for signs and symptoms. The sensitivity for the group receiving monitoring and nursing support in detecting preterm labor was 93%. The majority of false-positive visits were associated with patient symptoms. These data show that this combination service does not lead to a clinically significant increase in unscheduled visits. Further, the visits resulting from the combination service provide a sensitive predictive method to aid physicians in detecting early labor.

Clinical Trials as Topic↗
PubMed1990

Relationship of uterine contractility to preterm labor.

An increased uterine contraction rate is associated with preterm labor. The contraction rate in individual patients, however, has not been evaluated critically as to its predictive value in forecasting early labor. In this randomized multicenter study, 105 patients at high risk for preterm delivery monitored their contraction rate at home on a daily basis. An analysis was conducted to determine the association of at least four contractions per hour on a routine strip followed by at least four contractions per hour on a repeat tracing with subsequent preterm labor. Using this threshold, 70% of the patients were correctly classified. This contraction rate resulted in a sensitivity of 57%, a specificity of 80%, a positive predictive value of 72%, and a negative predictive value of 68%. A threshold rate of at least four contractions per hour on a remonitor strip identifies a patient at increased risk for preterm labor (P = .003).

Cardiotocography↗