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Biomedical subjects

D R Coustan

Publications and source records attributed to D R Coustan.

At least 55 records · Page 3Linked to original sources
PubMed1989

Precision of reflectance meters in screening for gestational diabetes.

The use of reflectance meters to screen for gestational diabetes has been advocated because of convenience and apparent accuracy. The present study addresses the possibility that imprecision of reflectance meters may affect the reliability of the blood sugar values obtained with their use. We tested four reflectance meters (Glucometer, Glucometer II, Glucoscan 3000, and Accuchek II) on 84 gravidas undergoing 1-hour, 50-g glucose screening, and calculated average coefficients of variation (9.6 +/- 10.9, 8.2 +/- 4.7, 6.8 +/- 4.5, and 7.4 +/- 4.4%, respectively). One-way analysis of variance testing indicated no significant difference between these values (P = .11). However, comparison with the coefficients of variation from standard laboratory technology (YSI Model 23A Glucose Analyzer) applied to simultaneously obtained venous samples (2.3 +/- 1.5, 1.5 +/- 0.6, 1.9 +/- 1.0, and 1.0 +/- 0.5%) revealed that the meters all had coefficients of variation significantly higher (P less than .0001). Use of reflectance meters would have resulted in 45.2% (38 of 84) of the subjects undergoing 3-hour oral glucose tolerance tests. Use of standard laboratory values would have indicated these tests in only 16% (14 of 84). The inconvenience and increased cost of these oral glucose tolerance tests suggest that meters may not be appropriate for screening.

Blood Glucose↗
PubMed1988

Fetal heart rate response to maternal exertion.

Doppler monitoring of fetal heart rates during maternal exertion has suggested that fetal bradycardia occurs frequently during vigorous exercise, causing concern for fetal safety. Doppler determination of fetal heart rate during vigorous maternal effort is difficult. To avoid motion artifact, we observed fetal heart rate using two-dimensional ultrasound and determined the incidence of fetal bradycardia in 45 pregnant women (age, 29.0 +/- 3.7 years [mean +/- SD]; gestational age, 25.2 +/- 3.0 weeks) during 85 submaximal and 79 maximal cycle ergometer tests. Average fetal heart rate did not change during exercise. A single episode of fetal bradycardia (heart rate less than 110 beats per minute for greater than or equal to 10 s) occurred during submaximal exertion during a maternal vasovagal episode. Sixteen episodes of fetal bradycardia were noted within three minutes after cessation of exercise, 15 of which followed maximal maternal effort. We conclude that brief submaximal maternal exercise up to approximately 70% of maximal aerobic power (maternal heart rate less than or equal to 148 beats per minute) does not affect fetal heart rate. In contrast to submaximal maternal exertion, maximal exertion is commonly followed by fetal bradycardia. This may indicate inadequate fetal gas exchange.

Adult↗
PubMed1988

Postpartum testing for antecedent gestational diabetes.

Gestational diabetes is a predictor of glucose intolerance in subsequent pregnancies and in the nongravid state. Many pregnant women are not tested for gestational diabetes, although they or their offspring may show signs suggestive of antecedent hyperglycemia. We examined the diagnostic utility of a postpartum (within 48 hours), 100 gm, oral glucose tolerance test and cord plasma glucose, cord plasma C-peptide, and 2-hour neonatal plasma glucose tests to detect antecedent gestational diabetes in women with documented gestational diabetes (n = 37) or with normal glucose tolerance test results late in the third trimester (n = 28). The 1-hour, 2-hour, and incremental 1-hour + 2-hour [( 1-hour - fasting] + [2-hour - fasting]) [2-hour - fasting]) glucose values of the postpartum glucose tolerance test showed significant differences between study participants with and without gestational diabetes (164 +/- 30 versus 115 +/- 22, 145 +/- 31 versus 101 +/- 21, and 153 +/- 51 versus 67 +/- 33 mg/dl, respectively, p less than 0.025). Maternal fasting and 3-hour postpartum glucose tolerance test glucose, cord plasma glucose, cord plasma C-peptide, and 2-hour neonatal plasma glucose values showed no significant between-group differences. Receiver operating characteristic curve analyses for these tests indicated that the incremental 1-hour + 2-hour postpartum glucose tolerance test glucose values best sustain test specificity at the low test threshold values necessary for high test sensitivity. A threshold of 110 mg/dl for this test yielded a predicted specificity of 90% and sensitivity of 80% with regard to antecedent gestational diabetes.

Birth Weight↗
PubMed1988

Diabetic nephropathy: pregnancy performance and fetomaternal outcome.

A study of 31 continuing pregnancies complicated by diabetic nephropathy was conducted to determine the effects of diabetes-associated renal disease on maternal health and fetal outcome. Throughout pregnancy there was a significant increase in maternal blood pressure (p less than 0.001) and proteinuria (p less than 0.0001), with nephrotic syndrome (greater than 3.0 gm protein/day) developing in 71% of pregnancies. After birth, however, proteinuria reverted to levels not significantly different from values in early pregnancy. There was no apparent adverse effect of pregnancy on the natural course of the underlying renal disease. Stillbirths occurred in two patients (6%), and the remaining 29 pregnancies resulted in live-births at a mean gestational age of 36 weeks. Seventy percent of these infants were appropriate for gestational age, whereas 16% were small and 13% were large for gestational age. Birth weight was best correlated with gestational age and creatinine clearance (p less than 0.0001). Neonatal complications included respiratory distress syndrome (19%), hyperbilirubinemia (26), and congenital malformations (10%). The uncorrected perinatal survival rate was 94%. These data suggest that with contemporary methods of maternal evaluation and treatment, fetal surveillance, and neonatal care, the risks to patients with diabetic nephropathy during pregnancy are not excessive. The likelihood of a successful fetal and neonatal outcome is comparable to that in other patients with insulin-dependent diabetes.

Adolescent↗
PubMed1988

Prediction of VO2max during cycle exercise in pregnant women.

We measured maximal O2 uptake (VO2max) during stationary cycling in 40 pregnant women [aged 29.2 +/- 3.9 (SD) yr, gestational age 25.9 +/- 3.3 wk]. Data from 30 of these women were used to develop an equation to predict the percent VO2max from submaximal heart rates. This equation and the submaximal VO2 were used to predict VO2max in the remaining 10 women. The accuracy of VO2max values estimated by this procedure was compared with values predicted by two popular methods: the Astrand nomogram and the VO2 vs. heart rate (VO2-HR) curve. VO2max values estimated by the derived equation method in the 10 validation subjects were only 3.7 +/- 12.2% higher than actual values (P greater than 0.05). The Astrand method overestimated VO2max by 9.0 +/- 19.4% (P greater than 0.05), whereas the VO2-HR curve method underestimated VO2max by only 1.6 +/- 10.3% in the same 10 subjects (P greater than 0.05). Both the Astrand and the VO2-HR curve methods correlated well with the actual values when all 40 subjects were considered (r = 0.77 and 0.85, respectively), but the VO2-HR curve method had a lower SE of prediction than the Astrand method (8.7 vs. 10.4%). In a comparison group of 10 nonpregnant sedentary women (29.9 +/- 4.5 yr), an equation relating %VO2max to HR nearly identical to that obtained in the pregnant women was found, suggesting that pregnancy does not alter this relationship. We conclude that extrapolating the VO2-HR curve to an estimated maximal HR is the most accurate method of predicting VO2max in pregnant women.

Adult↗
PubMed1988

The effect of intraumbilical oxytocin on the third stage of labor.

To determine whether intraumbilical oxytocin would shorten the third stage of labor, we enrolled 50 normal parturients into a randomized, double-blind protocol. Either 10 U of oxytocin diluted to 20 mL in normal saline (25 subjects) or 20 mL of normal saline alone (25 subjects) was injected into the placental circulation within one minute after cord clamping. The mean (+/- SD) duration of the third stage was 4.1 +/- 2.0 minutes in saline-treated subjects and 4.6 +/- 3.4 minutes in those treated with oxytocin. Intraumbilical oxytocin was not effective in shortening the normal third stage of labor.

Adult↗
PubMed1987

The "breakfast tolerance test": screening for gestational diabetes with a standardized mixed nutrient meal.

In a group of 50 presumed normal pregnant women and 20 known gestational diabetic women, all in the early third trimester, the function of a standard 50 gm, 1-hour screening test for gestational diabetes was compared with that of a plasma glucose level determined 1 hour after the ingestion of a standard 600 kcal mixed nutrient breakfast (breakfast tolerance test). The mean plus 2 SD for the breakfast tolerance test was 120 mg/dl. If this were used as the threshold for a screening test, 75% of cases of gestational diabetes would be identified (sensitivity), while 94% of normal pregnant women would be excluded (specificity). A threshold of 100 mg/dl yields a sensitivity of 96% and a specificity of 74%. These results are compared with those for the standard 50 gm glucose challenge.

Adult↗
PubMed1987

Clinical aspects of antenatal enhancement of pulmonary maturation.

The background, history, and physiologic basis for the use of corticosteroids to enhance fetal pulmonic maturation are presented. Clinical data relevant to this topic are discussed, and recommendations for the use of these agents are proposed. Finally, other pharmacologic agents that may become clinically useful for this indication are described.

Animals↗
PubMed1986

A randomized clinical trial of the insulin pump vs intensive conventional therapy in diabetic pregnancies.

Improved perinatal outcome is associated with the prevention of hyperglycemia during pregnancy in diabetic women. To determine whether the method of insulin administration influences the degree of diabetic control obtained, we randomized 22 pregnant diabetic women to intensive conventional insulin therapy (N = 11) and insulin pump therapy (N = 11). Frequent outpatient visits; home glucose monitoring, at least six times daily; and frequent telephone contact were offered to all subjects. Patients were hospitalized in the inpatient clinical research center each trimester for a 24-hour metabolic profile. There were no differences between the two treatment groups with respect to outpatient mean glucose levels, symptomatic hypoglycemia, or glycosylated hemoglobin levels, or with respect to inpatient mean glucose level, glycemic excursions, chemical hypoglycemia, or hyperglycemia. Excellent metabolic control was achieved with both treatment methods.

Adult↗
PubMed1986

Pregnancy as state of physiologic absorptive hypercalciuria.

An increase in circulating, 1,25-dihydroxyvitamin D level and net intestinal calcium absorption have been previously demonstrated in pregnant women and have been widely regarded as compensatory mechanisms whereby fetal mineral demands are satisfied. The alternate possibility, that these adjustments might anticipate such demands, has not previously been considered. To examine the effects of pregnancy on the intestinal absorption and renal excretion of calcium, oral calcium tolerance tests were performed and urinary calcium excretion was measured in 16 healthy women receiving a moderate calcium intake during and after pregnancy. Circulating 1,25-dihydroxyvitamin D levels and indexes of parathyroid function were also measured. As expected, 1,25-dihydroxyvitamin D levels were significantly (p less than 0.05) elevated throughout pregnancy (94 +/- 11, 118 +/- 9, and 117 +/- 11 pg/ml in the first, second, and third trimesters, respectively, versus 51 +/- 5 pg/ml after delivery). Twenty-four-hour calcium excretion also increased sharply (247 +/- 54, 316 +/- 42, 300 +/- 61 mg versus 91 +/- 18 mg), often to the point of hypercalciuria. Calcium tolerance test results included significant increases in the calciuric and calcemic responses during each trimester, whereas fasting calcium excretion and parathyroid function remained normal. These findings portray normal pregnancy as a state of physiologic absorptive hypercalciuria and call into question the widespread practice of supplementing calcium intake in otherwise well-nourished women during pregnancy.

Adult↗
PubMed1986

Coronary artery disease in diabetic pregnancies.

Severe vascular complications of diabetes mellitus include myocardial infarction and when this occurs during pregnancy it is associated with a high risk of maternal mortality. In the absence of myocardial infarction, information is unavailable on pregnancy outcome in diabetic patients with severe coronary artery disease or with prior coronary artery bypass graft. Such a case is presented together with a review of the literature.

Adult↗
PubMed1986

Should the fifty-gram, one-hour plasma glucose screening test for gestational diabetes be administered in the fasting or fed state?

To determine whether the 50 gm, 1-hour plasma glucose screening test for gestational diabetes should be administered in the fasted or fed state, 50 presumed normal and 20 gestational diabetic pregnant women in the early third trimester underwent this test twice, once under each condition, within a 1-week interval. There was no difference in test results under the two conditions among the normal individuals (fasted 118.4 +/- 24.7 mg/dl; fed 115.8 +/- 23.4 mg/dl). However, when the test was administered to women with known gestational diabetes, the result was significantly (p = 0.011) higher if patients were fasted (173.9 +/- 28.8 mg/dl) than if they had been given a standard 600 kcal meal 1 hour previously (154.8 +/- 24.1 mg/dl). The effect of these two conditions on the sensitivity and specificity of the screening test is described, and it is suggested that the threshold for glucose tolerance testing be 130 mg/dl if the test is administered in the fed state.

Adult↗
PubMed1986

Effects of maternal transport on admission patterns at a tertiary care center.

Major changes have occurred in the delivery of perinatal care during the last two decades. Documentation of perinatal regionalization statistics at Women and Infants Hospital of Rhode Island in Providence support the increasing proportion of low birth weight infants in the region being born at the tertiary care center, the decreasing number of neonatal transports in concert with an increasing number of maternal transports, and the increasing proportion of neonatal transports with birth weights greater than or equal to 2500 gm. Patterns of modern perinatal care are materially changing the delivery of health care at tertiary care facilities.

Birth Weight↗
PubMed1985

Prepartum diagnosis of traumatic fetal-maternal hemorrhage.

The diagnosis of significant fetal-maternal hemorrhage due to abdominal trauma was made upon detection of fetal red cells in the maternal circulation before delivery, and prompted immediate intervention despite an equivocal fetal monitor tracing. Histologic examination of the placenta identified the area of disruption of the fetal circulation, and the clinical condition of the neonate confirmed the diagnosis. A test for fetal-maternal hemorrhage would be appropriate in the evaluation of any pregnant woman sustaining trauma to the abdomen.

Abdominal Injuries↗