Biomedical subjects

James N Martin

Publications and source records attributed to James N Martin.

11 recordsLinked to original sources

PubMed2003

Postpartum seizure prophylaxis: using maternal clinical parameters to guide therapy.

OBJECTIVE: To use individual patient clinical parameters to signal cessation of postpartum magnesium sulfate seizure prophylaxis for the spectrum of pregnancy-related hypertensive disorders. METHODS: This was a prospective study using clinical symptoms (absence of headache, visual changes, epigastric pain) and signs (sustained blood pressure less than 150/100 without need for acute antihypertensive therapy, spontaneous diuresis more than 100 mL per hour for no less than 2 hours) to signal cessation of intravenous magnesium sulfate postpartum in gravidas diagnosed with preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelets syndrome. Laboratory assessments (including proteinuria) were not used as criteria for drug discontinuation. RESULTS: Five hundred three patients were enrolled and classified according to American College of Obstetricians and Gynecologists criteria (mild preeclampsia, severe preeclampsia, chronic hypertension with superimposed preeclampsia, eclampsia, and hemolysis, elevated liver enzymes, low platelets syndrome). Maternal age, gestational age, and hours of magnesium therapy before delivery were not statistically different among groups. There was no significant difference in the duration of postpartum magnesium sulfate therapy among groups with the median duration of therapy 4 hours (range 2-77 hours). No eclamptic seizures occurred after magnesium discontinuation. Thirty-eight patients (7.6%) required reinstitution of magnesium therapy for 24 hours because of exacerbation of blood pressure (sustained blood pressure more than 160/110) associated with headache or visual changes. CONCLUSION: Clinical criteria, when compared with arbitrary protocols, can be used successfully to shorten the duration of postpartum magnesium sulfate administration for seizure prophylaxis in patients with pregnancy-related hypertensive disorders.

Adult↗

PubMed2003

Effect of maternal hydration on amniotic fluid volume.

OBJECTIVE: To estimate the effects of maternal intravenous hydration on amniotic fluid volume in normal pregnancies. METHODS: Women undergoing an amniocentesis for the evaluation of fetal lung maturity before an elective cesarean delivery were eligible to participate. An amniotic fluid index (AFI) was obtained before the amniocentesis, and at the time of the amniocentesis the amniotic fluid (AF) volume was determined by diazo-dye reaction with subsequent spectrophotometric analysis of AF samples. If the AF sample drawn for fetal maturity studies was mature, the patient was hydrated with 1000 mL of balanced salt solution 30 minutes before her cesarean delivery. Amniotic fluid volume was subsequently estimated after the hydration by a repeat AFI. Amniotic fluid volume was directly measured at cesarean delivery and compared with the dye-determined volume. The pre- and posthydration AFI were also compared. RESULTS: A total of 17 women participated in the study between January 2001 and June 2001. Statistically significant increases in the AF volume and AFI were found. The prehydration median AF volume was 450 mL (range 250-953), and the median increase in AF volume was 188 mL (95% confidence interval [CI] 60, 254 mL; P <.001). Median AFI was 8.6 (range 5.8-17.8) with a median change in AFI of 1.7 cm (95% CI 1.1, 3.0; P <.001). CONCLUSION: Maternal intravenous hydration appears to increase both the actual and ultrasound-estimated AF volumes in normal third-trimester pregnancies.

Adult↗

PubMed2003

Evaluation of a rat model of preeclampsia for HELLP syndrome characteristics.

OBJECTIVE: To determine whether a rat model of preeclampsia includes features consistent with HELLP (hemolysis, elevated liver enzymes, low platelets) syndrome. METHODS: Preeclampsia was induced experimentally in timed-pregnant Sprague-Dawley rats using the reduced uterine perfusion pressure (RUPP) model. On day 14 of gestation, silver clips were placed around the aorta below the renal arteries and on the left and right uterine arcade at the ovarian artery. All animals were chronically instrumented to determine conscious blood pressure and to obtain blood samples for analysis of complete blood count, platelet count, liver function tests, uric acid, creatinine, and albumin. Blood samples were collected and animals sacrificed on day 19 of gestation, at which time placental and pup weight were obtained. A control group was analyzed similarly. Statistical analysis was performed with the Student t test. RESULTS: The RUPP model animals (n = 8), when compared with the normotensive controls (n = 9), did not show a statistically significant difference in hemoglobin, platelets, liver function tests, uric acid, creatinine, or albumin, although the mean arterial pressure was higher (mean +/- SD 131.9 +/- 17.1 mmHg versus 104.0 +/- 14.0 mmHg, respectively; P = .003) and pup number was lower (RUPP 6.6 +/- 2.4 versus control 13.8 +/- 2.3, P < .001). CONCLUSION: Although decreased uteroplacental perfusion induces changes similar to symptoms of preeclampsia, the RUPP rat model does not appear to express features of HELLP syndrome.

Animals↗

PubMed2003

Comparability of the amniotic fluid index and single deepest pocket measurements in clinical practice.

Two ultrasound techniques, the amniotic fluid index (AFI) and the single deepest pocket (SDP), are currently used to detect oligohydramnios, predict variable decelerations, risk of Caesarean delivery for fetal distress, Apgar scores, umbilical cord artery pH, perinatal mortality, and cerebral palsy. Both techniques poorly identify oligohydramnios. Both techniques identify pregnancies at risk for variable decelerations, low Apgar scores, and Caesarean delivery for fetal distress. Only the SDP is predictive of a compromised fetus-umbilical artery pH, as a stand-alone test, has been correlated with perinatal mortality, and as part of the biophysical profile has been linked to cerebral palsy. This brief communication reviews the comparability of these two techniques and which method, if either, is superior in the identification of oligohydramnios, the predictability of these techniques to identify an adverse pregnancy outcome, and the ability to predict cerebral palsy and perinatal mortality.

Amniotic Fluid↗

PubMed2003

Predictability of intrapartum and neonatal outcomes with the amniotic fluid volume distribution: a reassessment using the amniotic fluid index, single deepest pocket, and a dye-determined amniotic fluid volume.

OBJECTIVE: The purpose of this study was to establish whether ultrasound-estimated or dye-determined amniotic fluid distribution (upper compared with lower quadrant) is predictive of perinatal outcome. STUDY DESIGN: Amniotic fluid distribution as measured by the amniotic fluid index, single deepest pocket, and dye-determined volumes was ascertained and correlated with intrapartum and neonatal outcomes. RESULTS: Between January 1997 and January 2001, 135 women (70 upper-greater and 65 lower-greater) participated in this prospective observational study. The sum of the amniotic fluid index (P =.309), single deepest pocket (P =.168), and dye-determined amniotic fluid volume (P =.368) for the upper-greater compared with the lower-greater groups were similar. Decelerations in labor (P =.597), late decelerations (P =.999), cesarean deliveries for fetal distress (P =.413), and umbilical cord pH < 7.2 were similar (P =.647) CONCLUSION: Ultrasound-estimated and dye-determined amniotic fluid volumes are similar between upper-greater and lower-greater groups, and intrapartum/neonatal outcomes are not affected by the amniotic fluid distribution.

Adult↗

PubMed2003

Cesarean delivery for fetal distress: rate and risk factors.

UNLABELLED: The objective of this article was to review the recent English language literature on cesarean delivery for fetal distress to determine its incidence, diagnostic tests, and the contributing factors to this obstetric complications. A PubMed search (1990-2000) with items of "cesarean, fetal distress," "cesarean, non-reassuring fetal heart rate," "cesarean, neonatal acidosis," and "cesarean, umbilical arterial pH," was undertaken. Reports, letters to the editor, focus on anomalous fetuses, and papers not specifically focused on this topic were excluded. Of the 392 articles that the search yielded, 169 met the inclusion criteria. Based on 37 reports with more than 1,000 patients each, the overall risk of prompt cesarean delivery for fetal concern was 3.1% (43,340 of 13,989,74). The risk exceeded 20% in patients with moderate/severe asthma, severe hypothyroidism, severe preeclampsia, and postterm or fetal growth restricted fetuses with abnormal Doppler studies. Use of likelihood ratios suggests that Doppler of the umbilical artery is a superior diagnostic test to amniotic fluid index in identifying parturients at risk for cesarean for non-reassuring fetal heart rate tracing. Although several risk factors increase the need for cesarean delivery for fetal distress, in general, most are unpreventable. TARGET AUDIENCE: Obstetricians & Gynecologists, Family Physicians. LEARNING OBJECTIVES: After completion of this article, the reader will be able to estimate the incidence of cesarean delivery for non-reassuring fetal heart rate tracing, outline potential diagnostic tests that are useful for the detection of fetal distress, and summarize medical and obstetric conditions that place patients at risk for cesarean delivery for fetal distress.

Adult↗

PubMed2002

Markedly elevated beta-hCG levels in a normal singleton gestation with hyperreactio luteinalis.

BACKGROUND: Human chorionic gonadotropin (hCG) is produced by the trophoblast early in pregnancy and peaks at a level of approximately 100,000 IU/liter around the ninth week of gestation. Abnormally high levels are usually noted in association with multiple gestation, molar gestation, and specific ovarian or gestational malignancies. CASES: A multiparous patient in the second trimester was referred for evaluation after a maternal triple marker screen was incalculable due to a beta-hCG level of 2.1 million IU/L. Targeted sonography revealed bilateral complex adnexal masses with a solid component of the left ovary, a normal fetus, and normal placenta. The patient underwent an exploratory laparotomy at 18 weeks' gestational age. A left oophorectomy was performed. Pathology confirmed hyperreactio luteinalis. The remainder of the pregnancy was remarkable for preterm labor and delivery at 35 weeks' gestational age. At delivery, the hCG level was noted to be 24,210 IU/L, and the fetus and placenta were normal. CONCLUSION: Markedly elevated hCG levels rarely occur in normal singleton pregnancy and can be associated with hyperreactio luteinalis. When noted, a work-up to evaluate possible malignancy, molar gestation, and multiple gestation should be pursued.

Adult↗

PubMed2002

Pregnancy after classic cesarean delivery.

OBJECTIVE: To describe maternal and perinatal outcomes after a prior classic cesarean delivery. METHODS: A retrospective review was performed including all patients from 1990-2000 whose most recent pregnancy was preceded by classic cesarean delivery. RESULTS: During the 11-year period, there were 37,863 deliveries and 157 patients (0.4%) underwent classic cesarean operations. In the next pregnancy, one case of uterine rupture (0.6%, 95% confidence interval 0.1, 3.5) occurred at 29 weeks without preterm labor and resulted in fetal death. The prevalence of asymptomatic dehiscence was 9% (95% confidence interval 5, 15). There was no significant difference between patients with uterine dehiscence (n = 15) and patients with intact uteri (n = 141) with regard to maternal demographics, duration of labor, cervical dilatation at time of surgery, transfusion of packed red cells, bowel injury, postpartum endometritis, wound breakdown, thrombophlebitis, or umbilical arterial pH less than 7.00 (P >.05). Duration of labor, cervical dilatation, and gestational age at repeat cesarean delivery were poor predictors for uterine rupture or dehiscence. CONCLUSION: Among patients with prior classic cesarean delivery, uterine rupture and dehiscence are neither predictable nor preventable. One in four patients will experience some form of maternal morbidity. Uterine rupture, although infrequent, can be fatal to the fetus. Uterine dehiscence, however, does not increase neonatal or peripartum maternal morbidity.

Cesarean Section↗

PubMed2002

Subcutaneous stitch closure versus subcutaneous drain to prevent wound disruption after cesarean delivery: a randomized clinical trial.

OBJECTIVE: The purpose of this study was to compare a subcutaneous stitch closure and subcutaneous drain placement for the risk of wound disruption after cesarean delivery. STUDY DESIGN: This was a prospective randomized clinical trial that evaluated subcutaneous stitch closure, placement of a subcutaneous drain, or no closure for subsequent wound disruption risk in women with subcutaneous depth at >or=2 cm. RESULTS: The maternal demographics and intrapartum risk factors for postoperative wound disruptions were similar among the 964 study subjects, who were divided into 3 groups. Wound disruptions that required opening of the wound, irrigation, debridement, packing, and/or secondary delayed closure occurred in 9.7% of the women with no closure, 10.4% of the women in the stitch closure group, and 10.3% of the women in the closed drain group (P =.834). CONCLUSION: There appears to be no difference in the subsequent risk of wound complications when no closure of the subcutaneous tissue layers occurs versus suture closure or a closed drainage system.

Adult↗

PubMed2002

Intra-operative haemorrhage by blunt versus sharp expansion of the uterine incision at caesarean delivery: a randomised clinical trial.

OBJECTIVE: To determine whether the method used to expand the uterine incision for caesarean delivery affects the incidence of intra-operative haemorrhage. DESIGN: A prospective randomised study of women undergoing a low segment transverse caesarean delivery. Participants were assigned to have their uterine incision either sharply or bluntly expanded. PARTICIPANTS: Between June 1998 and June 2000, 470 women drew assignments to the sharp expansion group and 475 to the blunt group. RESULTS: The maternal demographics of age, race, nulliparity, and body mass index as well as pre-operative haematocrit were similar between groups. Compared with the blunt group, the estimated blood loss (886 versus 843mL, P = 0.001), change in the mean haematocrit (6.1% versus 5.5%, P = 0.003), incidence of postpartum haemorrhage (13% versus 9%; relative risk = 1.23, 95% CI 1.03, 1.46) and need for a transfusion (2% versus 0.4%; relative risk = 1.65, 95% CI 1.25, 2.21) were significantly greater in the sharp group. CONCLUSION: In caesarean delivery, sharply expanding the uterine incision significantly increases intra-operative blood loss and the need for subsequent transfusion.

Adult↗

PubMed2002

Preeclampsia: pathophysiology and practice considerations for the consulting nephrologist.

Abnormal placental implantation presumed to be secondary to maternal genetic susceptibility or immune maladaptation is considered to be fundamental to the pathogenesis of preeclampsia. The reduced placental perfusion resulting in placental ischemia is hypothesized to cause the known endothelial dysfunction, which leads to the clinical manifestations of this disease. Oxidative stress is a postulated linking factor, an aberration that possibly has its genesis via cytokines released from the abnormally implanted and perfused placenta. Clearly the maternal pathophysiologic changes that subsequently produce what is recognized as preeclampsia are present long before the disease makes its clinical appearance.

Cytokines↗