The effects of dexmedetomidine on spontaneous contractions of isolated gravid rat myometrium

Abstract

The direct effects of dexmedetomidine on isolated gravid rat myometrium were investigated in this in vitro study; such effects may have clinical repercussions in the administration of anesthesia to obstetric patients. Samples of myometrium were taken from 12 gravid rats. Myometrial strips were dissected microscopically and mounted on the myograph at a resting tension of 1 g in bath that contained Krebs solution. After spontaneous contractions of the myometrium had been steadily established, increasing concentrations of dexmedetomidine were added to baths via micropipette, and the effects of these additions were recorded via myograph. Dexmedetomidine in vitro caused a significant increase in the amplitude, frequency, and area under the curve of myometrial contractions in a dose-dependent manner. Results of this study demonstrate that dexmedetomidine increases spontaneous contractions in rat myometrium; however, further investigation is needed to clarify the usefulness of dexmedetomidine in the administration of obstetric anesthesia.

Study of the Effect of Dexmedetomidine in Reducing Hemodynamic Responses to General Anesthesia for Elective Cesarean Section in Patients with Preeclampsia

“…There were many case reports of use of dexmedetomidine in parturients after the proof of its retention in the placenta with negligible effect on the fetus [17,18].…”

Effects of Subchronic versus Acute in utero Exposure to Dexmedetomidine on Foetal Developments in Rats

“…Intravenously administered dexmedetomidine as a pre-anaesthetic has been shown to decrease thiopental anaesthetic requirements and improve recuperation from anaesthesia with no serious haemodynamic or other adverse effects in patients undergoing gynaecological surgery [17]. Recently, in vitro exposure of dexmedetomidine significantly and dose-dependently increased the spontaneous contractions in myometrial strips of pregnant rats suggesting the relevance of dexmedetomidine in obstetric anaesthesia [18]. Although the above findings confirm the safety of dexmedetomidine-induced anaesthesia/analgesia for various operations, its use for labour analgesia is not a common practice, probably due to the lack of information about the effects of maternally administered dexmedetomidine on neonatal outcome.…”

Intravenous Dexmedetomidine for Labour Analgesia in Women With Preeclampsia

“…Also, it increases the frequency and amplitude of uterine contraction directly. [7] There were many case reports of use of dexmedetomidine in parturients after the proof of its retention in the placenta with negligible effect on the foetus. There are several case reports describing successful use of dexmedetomidine in labour analgesia if regional was contraindicated, if patient was not willing for labour epidural or as an adjunct to labour epidural if pain relief was not satisfactory without any adverse foetal outcomes in the recommended doses (1 ug/kg loading dose over 10-15 minutes followed by an infusion at 0.2-0.7 ug/kg/hour).…”

“…The uterine contraction after placental delivery was assessed by the obstetrician and scored from 0 to 3 according to the Visual Analogue Scale (VAS). [7] as 0 means complete uterine relaxation and 3 refers to best contraction. Apgar score of the neonates was assessed by the paediatrician, also all neonates were observed for respiratory depression and bradycardia during the first hour after delivery.…”