Postpartum Women's Dexmedetomidine Sedation

Optimal Dose of Dexmedetomidine Sedation Following Spinal Anesthesia: Postpartum Versus Nonpregnant Women

Currently, spinal anesthesia is most commonly used for cesarean section.But spinal anesthesia can not block the visceral vagus nerve, and the patients are prone to nausea, vomiting, chest tightness or other discomfort when the uterus is stretched .For parturients who have poor uterine contractions and are bleeding larger, obstetricians often use oxytocin to strengthen the contraction of the uterine,which also would increase the parturients' discomfort.Anesthesiologists often intravenous sedative hypnotics (eg.propofol or midazolam) to alleviate the fear of the parturients after the baby is delivered.One of the side effects of propofol or midazolam is that they would lead to the respiratory depression.For the poor respiratory reserve of the parturients, functional residual capacity(FRC) of this group could be reduced by up to 20%, and the oxygen consumption was also increased.The SPO2 could decline quickly intraoperatively.Dexmedetomidine is a novel , highly selective α2 adrenergic receptor agonists , and its selectivity for α2 receptor is 1600 times higher than α1.It also could provide dose-dependent sedation , analgesia , anti-anxiety and inhibition of sympathetic nerves and other effects.Because of its minimal impact on the respiratory , it could safely and effectively used to sedate patients undergoing cesarean section.But the change of endocrine system and hemodynamic of the parturients may affect the pharmacokinetics and pharmacodynamics of some anesthetic drugs.Currently studies have demonstrated the increased sensitivity of some anesthetic drug in parturients, such as lidocaine and isoflurane.The study is aim to explore the optimal dexmedetomidine dose to produce suitable sedation in parturients ,and compared with norman nonpregnant women.

Study Overview

• Status: Completed
• Conditions: Cesarean Section
• Intervention / Treatment: Drug: Dexmedetomidine 01; Drug: Dexmetomidine 02

Detailed Description

Parturients undergo cesarean section and normal nonpregnant women undergo lower abdominal surgery were scheduled . All patients accepted spinal anesthesia first.And then an dose of dexmedetomidine would be performed after umbilical cord was clapped in the parturients and in non-pregnant women group the dose of dexmedetomidine would be performed after the spinal anesthesia was conducted.Initial doses was 1.0μg/kg,with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last four turning points. Each patient's sedation state was assessed using the modified observer's assessment of awareness /sedation (OAA/S) scale every 5 min after starting the dexmedetomidine infusion for 30 min. Adequate sedation was defined as an OAA/S≤3 at any assessment time point during the 30 min

• Study Type: Interventional
• Enrollment (Actual): 60
• Phase: Phase 4

Contacts and Locations

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510010
      • Guangzhou Military Region General Hospital, Department of Anesthesiology

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 20 years to 35 years (ADULT)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: Female

Description

Inclusion Criteria:

1. ASA Ⅰ ~ Ⅱ women undergoing cesarean surgery under spinal anesthesia
2. ASA Ⅰ ~ Ⅱ nonpregnancy women undergoing lower abdominal surgery under spinal anesthesia
3. Written informed consent from the patient or the relatives of the participating patient
4. nonpregnancy women BMI:18～25 kg/m2 , parturients BMI <35kg/m2

Exclusion Criteria:

1. Mental illness can not match
2. Spinal anesthesia contraindicated
3. People who have Slow-type arrhythmias
4. People who were language or hearing impaired
5. Sensory block reached to T6 or higher.
6. People who had lung infection or sleep apnea syndrome.
7. Chronic renal failure
8. Alcohol or drug abuse
9. Already taking gabapentin, pregabalin, benzodiazepin or antidepression drug

Study Plan

How is the study designed?

Design Details

• Primary Purpose: TREATMENT
• Allocation: NON_RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
EXPERIMENTAL: parturients; Parturients after the umbilical cord was clapped in cesarean section were accepted an initial dose of 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last four turning points.	Drug: Dexmedetomidine 01; Initial dose of dexmedetomidine was 1.0 μg/kg, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last four turning points,after the umbilical cord was clapped.The wight used to calculate the dose of dexmedetomidine would be that the total weight of the mother minus the weight of the placenta, amniotic fluid and fetal.
EXPERIMENTAL: nonpregnant women; Nonpregnant women were accepted an initial dose of 1.0 μg/kg dexmedetomidine, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last four turning points.	Drug: Dexmetomidine 02; Initial dose of dexmedetomidine was 1.0 μg/kg, with dose adjustment intervals of 0.1μg/kg in first three turning points and 0.05μg/kg in the last four turning points,as soon as the spinal anesthesia

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
The assessment of sedation	The aim of our study is to define the median effective sedative dose (ED50) of dexmedetomidine for providing adequate sedation in cesarean surgery,using the Dixon up-and-down method. Adequate sedation was defined as an OAA/S≤3 at any assessment time point during the 30 min after dexmedetomidine infusion.	every 5 min after starting the dexmedetomidine infusion for 30 min

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
comparision of ED50	compare the ED50 between postpartum parturients and nonpregnant women	every 5 min after starting the dexmedetomidine infusion for 30 min

Collaborators and Investigators

• Sponsor: Guangzhou General Hospital of Guangzhou Military Command

Publications and helpful links

General Publications

• Xiong M, Chen B, Hu Z, Gupta S, Li Z, Liu J, He J, Patel S, Eloy JD, Xu B. Dose Comparison of Dexmedetomidine Sedation following Spinal Anesthesia: Parturient versus Nonpregnant Women-A Randomized Trial. Anesthesiol Res Pract. 2020 Jul 27;2020:1059807. doi: 10.1155/2020/1059807. eCollection 2020.

Study record dates

Study Major Dates

• Study Start (ACTUAL): June 1, 2015
• Primary Completion (ACTUAL): March 1, 2016
• Study Completion (ACTUAL): April 1, 2016

Study Registration Dates

• First Submitted: April 7, 2014
• First Submitted That Met QC Criteria: April 10, 2014
• First Posted (ESTIMATE): April 11, 2014

Study Record Updates

• Last Update Posted (ACTUAL): November 28, 2017
• Last Update Submitted That Met QC Criteria: November 24, 2017
• Last Verified: November 1, 2017

More Information

Terms related to this study

• Keywords: dexmedetomidine; sedation; parturient; nonpregnant women
• Additional Relevant MeSH Terms: Physiological Effects of Drugs; Adrenergic Agents; Neurotransmitter Agents; Molecular Mechanisms of Pharmacological Action; Central Nervous System Depressants; Peripheral Nervous System Agents; Analgesics; Sensory System Agents; Analgesics, Non-Narcotic; Adrenergic alpha-2 Receptor Agonists; Adrenergic alpha-Agonists; Adrenergic Agonists; Hypnotics and Sedatives; Dexmedetomidine
• Other Study ID Numbers: Cesarean Surgery