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Biomedical subjects

M T Parsons

Publications and source records attributed to M T Parsons.

31 records · Page 2Linked to original sources

The prevention of meconium aspiration in labor using amnioinfusion.

In an effort to improve maternal and fetal outcome in patients laboring with thick meconium, 85 patients presenting with thick meconium were randomized to receive either amnioinfusion with 1000 mL normal saline initially and every 6 hours until delivery, or routine care. Meconium was discovered on initial examination during labor, after artificial rupture of membranes, through the use of an intrauterine pressure catheter, or on amniocentesis. Labor management was otherwise routine. Forceps operations and cesarean sections were for distress or failure to progress, as indicated. Patients receiving amnioinfusion had significantly fewer low 1-minute Apgar scores, less meconium below the cords, and a significantly lower incidence of operative delivery. The only three cases of meconium aspiration syndrome occurred in infants delivered of patients receiving routine management. No adverse side effects of amnioinfusion were detected. Amnioinfusion is a simple, inexpensive, and safe technique that reduces the incidence of meconium below the cords and improves obstetric outcome in patients laboring with thick meconium.

Adult↗

Prostaglandin production and contractile response of umbilical arteries in preeclamptic pregnancies with and without intrauterine growth retardation.

Biochemical and biophysical properties of umbilical arteries from normotensive and preeclamptic pregnancies were examined. The production of prostaglandins E and F, 6-keto-PGF1 alpha, and thromboxane B2 by umbilical arteries from normotensive, mildly preeclamptic, and severely preeclamptic pregnancies were measured in incubation media at baseline and after addition of arachidonic acid. The initial baseline values of 6-keto-PGF1 alpha were decreased in the severely preeclamptic patients with intrauterine growth retardation (IUGR) but not in any of the other groups. Addition of arachidonic acid resulted in a significant increase in 6-keto-PGF1 alpha production over initial baseline in all groups except in the severely preeclamptic pregnancies without IUGR. These results suggest a differential defect in the 6-keto-PGF1 alpha metabolic pathway in severely preeclamptic patients with IUGR compared with those without IUGR. The stretch response curve to serotonin was decreased in the severely preeclamptic group with IUGR compared with the control group. The contractile response to individual vasoactive agents (serotonin, prostaglandin F2, norepinephrine, angiotensin II, and arachidonic acid) showed no significant difference between the normotensive and preeclamptic groups.

Angiotensin II↗

Court-ordered obstetrical interventions.

In a national survey, we investigated the scope and circumstances of court-ordered obstetrical procedures in cases in which the women had refused therapy deemed necessary for the fetus. We also solicited the opinions of leading obstetricians regarding such cases. Court orders have been obtained for cesarean sections in 11 states, for hospital detentions in 2 states, and for intrauterine transfusions in 1 state. Among 21 cases in which court orders were sought, the orders were obtained in 86 percent; in 88 percent of those cases, the orders were received within six hours. Eighty-one percent of the women involved were black, Asian, or Hispanic, 44 percent were unmarried, and 24 percent did not speak English as their primary language. All the women were treated in a teaching-hospital clinic or were receiving public assistance. No important maternal morbidity or mortality was reported. Forty-six percent of the heads of fellowship programs in maternal-fetal medicine thought that women who refused medical advice and thereby endangered the life of the fetus should be detained. Forty-seven percent supported court orders for procedures such as intrauterine transfusions. We conclude from these data that court-ordered obstetrical procedures represent an important and growing problem that evokes sharply divided responses from faculty members in obstetrics. Such procedures are based on dubious legal grounds, and they may have far-reaching implications for obstetrical practice and maternal and infant health.

Attitude of Health Personnel↗

Thermic effects of tocolytic agents: decreased temperature with magnesium sulfate.

The effect of the tocolytic agents terbutaline and magnesium sulfate on patients' temperatures was examined. Fifty-two women admitted for preterm labor were randomized to a treatment protocol for one of the two agents. Oral temperatures were measured initially and every two hours during treatment. There was no significant difference between the initial temperature and the lowest temperature recorded during treatment in the terbutaline group, but temperature decreased significantly during treatment with magnesium sulfate. This decrease in maternal temperature may have importance in the treatment of preterm labor with magnesium sulfate in patients with an infectious etiology for uterine activity.

Adult↗

Appendectomy at cesarean section: a prospective study.

Appendectomy was performed on 40 consecutive consenting patients undergoing elective cesarean section in a clinic population. The control group consisted of all other patients undergoing elective cesarean section during the period of study. The populations were similar. Clinical infection, blood loss, gastrointestinal tract recovery rates were equal in both groups. Appendectomy added 15 minutes to the operation time and extended the hospital stay by about one-half day. There were no wound infections or serious morbidity. A fifth of the appendixes removed were abnormal, including two with inflammation and one with a carcinoid tumor. Prophylactic appendectomy does not seem to add to the risk of elective cesarean section.

Anesthesia↗

Prospective randomized study of x-ray pelvimetry in the primigravida.

A prospective randomized study was performed to determine the usefulness of x-ray pelvimetry before oxytocin induction or augmentation. Two hundred primiparous women were entered into this study. Agreement on pelvic size by the clinical and radiologic assessment occurred in 76.5% of the cases. When the total groups were compared, there were no differences in pregnancy outcome. In the induction of labor subgroups there were less forcep deliveries and lower five-minute Apgar scores in the pelvimetry group. In the augmentation subgroups there were no differences. The subgroup of patients diagnosed clinically to have a borderline pelvis, had a higher incidence of cesarean section (P less than .05) if they had x-ray pelvimetry. These results suggest that the elimination of x-ray pelvimetry in primigravida women does not lead to a compromise in infant outcome when electronic fetal monitoring is used.

Adult↗

Configuration of the fetal electrocardiogram in ambulatory women in labor monitored with wideband telemetry.

The fetal electrocardiogram (ECG) in 23 ambulatory women in labor was monitored successfully with a single-channel FM telemetry unit with a 0.5-100-Hz wideband receiver to improve the quality of the ECG complex. An inverted QRS complex was seen in a patient with a deceleration and an inverted T wave during a deceleration in a patient confined to bed. A maternal artifact was transmitted in a third. The ECG complex was identical when wired patients were switched to telemetry. Thus, fetal heart rate and ECG configuration can be monitored accurately in ambulatory pregnant women.

Ambulatory Care↗

Intraligamentous pregnancy. A case report.

A patient experienced fetal demise at 33 weeks' gestation. Numerous attempts at induction of labor failed. It was not until a laparotomy was performed that the intraligamentous location of the pregnancy was determined. Although this diagnosis is rarely made preoperatively, repeated failure of induction should raise the suspicion of an abnormal implantation site.

Adnexa Uteri↗

Comparison of the in vivo activity of different oxytocin antagonists in the pregnant baboon.

OBJECTIVE: To ascertain the relative activity of five oxytocin antagonists (OTAs) in vivo in a tethered pregnant baboon model and compare these results to previously reported affinities in human and rat oxytocin receptor assays and median effective dose in rat uterotonic bioassays. METHODS: Pregnant tethered baboons between days 130 and 160 of pregnancy were given an oxytocin challenge test 1 minute after infusion of 1 mg of one of five randomly selected OTAs: ANTAG I, ANTAG II, ANTAG III, L366948, and Atosiban. Once the uterine response to oxytocin returned to normal (1-8 days) the OCT was repeated with one of the remaining, untested OTAs during the 130-160 day period. Uterine activity, the time until the first significant response, and the dose of oxytocin needed to induce this response were all factored into one expression, the antagonist-response interval (ARI). RESULTS: When expressed as ratio to ANTAG I the relative ARI for the OTAs were 0, .5, 1.0, 2.4 and 59.2 for L366948, Atosiban, ANTAG I, ANTAG II, and ANTAG III, respectively. ANTAG III and L366948 were significantly different from each other and the three other OTAs (P < .05). The log10 ARI for the 4 active OTAs when correlated with the log10 of the human and rat oxytocin receptor affinities and the rat uterotonic bioassay were all highly correlated (r = .99; P < .05). CONCLUSION: ANTAG III is a potent, long-acting OTA in vivo in the pregnant baboon and has the potential as a tocolytic in humans.

Animals↗