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Biomedical subjects

E H Henriksen

Publications and source records attributed to E H Henriksen.

6 recordsLinked to original sources

Comparative maternal and neonatal effects of halothane and enflurane for cesarean section.

The effects of placental transfer of enflurane and halothane were studied in 81 women undergoing cesarean sections. All patients had rapid sequence induction using thiopental, succinylcholine, and endotracheal intubation. They were then randomly assigned to one of five groups: Group I (n = 16) received N2O and oxygen, Group II (n = 16) N2O, oxygen, and 0.25% halothane, Group III (n = 18) N2O, oxygen, and 0.5% halothane, Group IV (n = 18) N2O, oxygen, and 0.5% enflurane, Group V (n = 13) N2O, oxygen, and 1% enflurane. At delivery, blood was drawn from the maternal artery, umbilical vein and artery for measurement of the halogenated agents using gas chromatography. The neonates were evaluated by Apgar scores, umbilical artery and vein acid base status and the Early Neonatal Neurobehavioral Scores (ENNS) at 2 and 24 h of age. Blood loss and the incidence of maternal awareness were also determined. The umbilical vein to maternal vein ratio was approximately 0.5 and 0.6 for enflurane and halothane, respectively. The umbilical artery to umbilical vein ratio was 0.5 with both agents; higher inspired anesthetic concentrations produced higher blood levels. All neonates had Apgar scores of 8 or more at 5 min with the exception of one neonate in the N2O group. Maternal and neonatal acid base status, blood loss, and ENNS were not affected by the addition of the halogenated agents. Of the patients who had N2O alone, 12% had awareness versus none in the other groups. These data demonstrate that low dose halothane or enflurane decreases the incidence of maternal awareness and does not adversely affect the neonate.

Adult

Efficacy of clear antacid prophylaxis in obstetrics.

We studied 33 women scheduled to undergo general anesthesia for cesarean section. Prior to induction of anesthesia, each patient received in a random fashion one of two prophylactic antacids. Group I (n = 17) received 30 ml Gelusil orally and Group II (n = 16) received 30 ml of 0.3 mol/l sodium citrate. After induction of general anesthesia an oro-gastric tube was passed. The amount and pH of the gastric aspirate were measured at the time of delivery and 45 min after delivery "before extubation." Both antacids elevated gastric pH above 3.5 in all patients but one in the Gelusil group. The pH remained elevated 45 min later. It is concluded that 0.3 mol/l sodium citrate is effective as an antacid when given orally prior to induction of anesthesia.

Adult

Maternal catecholamines decrease during labor after lumbar epidural anesthesia.

To determine whether epidural anesthesia during labor affects maternal circulating catecholamines, blood samples were obtained from 15 patients at the peak of and immediately after two consecutive painful contractions. A lumbar epidural local anesthetic without epinephrine was then administered. After the onset of analgesia, four blood samples were again drawn. All samples were analyzed by a radioenzymatic assay for epinephrine and norepinephrine concentrations. Before anesthesia, the mean (+/-SEM) plasma epinephrine level was 280 +/- 49 pg/ml, and the mean norepinephrine level was 866 +/- 122 pg/ml. After anesthesia, epinephrine levels decreased 56% (p less than 0.01). Although norepinephrine levels decreased approximately 19%, this reduction was not statistically significant. At the height of a contraction, catecholamine levels did not differ significantly from those occurring between contractions. Lumbar epidural anesthesia during labor reduces maternal epinephrine levels, probably by eliminating the psychological and physical stress associated with painful uterine contractions or by denervating the adrenal medulla. Whatever the mechanism, reducing pain and activity of the sympathetic nervous system should increase uterine blood flow.

Anesthesia, Epidural

Effects of spinal anesthesia on maternal circulating catecholamines.

This study evaluated the effects of spinal anesthesia on maternal circulating catecholamines. Spinal anesthesia was administered in two groups of patients undergoing cesarean section. Nine patients were in labor; 14 were not in labor. Spinal anesthesia was followed by a significant reduction in norepinephrine (NE) in patients in labor (p less than 0.05). No such reduction was observed in the patients not in labor despite sensory levels of the fourth thoracic vertebra--or higher. There were no changes in epinephrine (E) levels in either groups. Ephedrine was administered to seven patients not in labor who developed hypotension. There were no significant changes in either NE or E.

Adult

Neonatal neurobehavioral effects of inhalation analgesia for vaginal delivery.

The authors studied the neonatal neurobehavioral effects of nitrous oxide:oxygen and enflurane:oxygen inhalation analgesia for vaginal delivery. Parturients were assigned randomly to receive no inhalation agent (Group 1, n = 21); enflurane, 0.3 to 0.8 per cent, and oxygen (Group 2, n = 22); or nitrous oxide, 30 to 50 per cent, and oxygen (Group 3, n = 18). Infants were tested at 15 min, 2 h, and 24 h of age using the Neurologic and Adaptive Capacity Score (NACS); and at 2 and 24 h using the Early Neonatal Neurobehavioral Scale (ENNS). No significant differences in neurobehavioral status occurred. For all groups, scores tended to be lowest at two hours of age. We conclude that neither enflurane nor nitrous oxide analgesia adversely affects neonatal neurobehavioral status at 15 min, 2 h, or 24 h of age.

Alphaprodine