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The Effect of Ondansetron on Spinal Anesthesia in Caesarean Section

Phase 3
Conditions
Hypotension
Interventions
Drug: 100ml normal saline 0.9 percent
Registration Number
NCT03931863
Lead Sponsor
Aretaieion University Hospital
Brief Summary

The purpose of this study is to compare the administration of two different doses of ondansetron to placebo to prevent hypotension and bradycardia following spinal anaesthesia. Apart from haemodynamic parameters (blood pressure and heart rate),characters of the spinal blockage (time of onset and regression) will be recorded too.

Detailed Description

The day before surgery the procedure will be explained to the patient and the written consent will be obtained. In the operating room, intraoperative monitoring will include electrocardiography (ECG), noninvasive blood pressure, oxygen saturation by pulse oximetry (SpO2) and heart rate (HR). Two peripheral intravenous catheters wil be placed for fluid replacement and administration of drugs.

Participants will be randomly assigned to one of the following groups:

Group A: Women will receive 4 milligrams (mg) of ondansetron diluted in 100 milliliters (ml) of normal saline 0.9 percent 10 minutes before spinal anaesthesia

Group B:Women will receive 8 mg of ondansetron diluted in 100ml of normal saline 0.9 percent 10 minutes before spinal anaesthesia

Group C:Women will receive 100ml of normal saline 0.9 percent 10 minutes before spinal anaesthesia

Subsequently, after receiving 500ml of colloid solution, spinal anesthesia will be performed at level L3-L4 or L4-L5 in the vertebral space with 1.6ml of 0.75 percent ropivacaine and 15mcg of fentanyl, using a 27-gauge pencil point spinal needle with patients in a left lateral position. After subarachnoid infusion, participants will be placed supine with left uterine displacement and anesthetic and motor blockage will be evaluated every one minute until anesthetic blockage reaches the level of T4 neurotome and the motor block becomes complete (Bromage grade 3). This time will be called Time to max effect (Tmax).

Hypotension, defined as systolic blood pressure below 100 millimeters of Mercury (mmHg), will be treated using 5mg ephedrine if the heart rate is less than 100 beats per minute or with 20mcg of phenylephrine if the heart rate is greater than 100 beats per minute. Bradycardia, defined as a fall in heart rate below 60 beats per minute will be treated with atropine (0.6mg).

Immediately after the delivery of the neonate, all women will receive a solution of oxytocin (20 units) intravenously. Half an hour before the end of the procedure they will receive an additional 1g of paracetamol and 75mg of diclofenac.

Recruitment & Eligibility

Status
UNKNOWN
Sex
Female
Target Recruitment
180
Inclusion Criteria
  • Physical status according to American Society of Anesthesiologists (ASA) I-II
  • Singleton pregnant women in full term pregnancy
  • Patients scheduled for cesarean section
  • Height 158cm-170cm
Exclusion Criteria
  • patient's own refusal
  • contraindications to spinal anesthesia (coagulation disorders, inflammation at the puncture site, allergy to local anesthetics)
  • ondansetron allergy
  • body mass index> 33kg / m^2
  • height <158cm, or> 170cm
  • hypertensive disorders of pregnancy
  • cardiovascular disease
  • receiving selective serotonin reuptake inhibitors (SSRI's) or treatment for migraine
  • placenta previa.

Study & Design

Study Type
INTERVENTIONAL
Study Design
PARALLEL
Arm && Interventions
GroupInterventionDescription
Group BOndansetron 8mgIntravenous administration of ondansetron 8mg diluted in 100ml of normal saline 0.9 percent within 10 minutes prior to spinal anesthesia.
Group C100ml normal saline 0.9 percentIntravenous administration of 100ml of normal saline 0.9 percent within 10 minutes prior to spinal anesthesia.
Group AOndansetron 4mgIntravenous administration of ondansetron 4mg diluted in 100ml of normal saline 0.9 percent within 10 minutes prior to spinal anesthesia.
Primary Outcome Measures
NameTimeMethod
Change from Baseline Systolic Blood Pressure during cesarean section60 minutes

every one minute after spinal anaesthesia and every five minutes after the delivery of the neonate until the end of the surgery

Change from Baseline Heart Rate60 minutes

every one minute after spinal anaesthesia and every five minutes after the delivery of the neonate until the end of the surgery

Secondary Outcome Measures
NameTimeMethod
Sensory blockade20 minutes

Time for onset of sensory block at T4

Motor blockade20 minutes

Time to Bromage 2 and to Bromage 3

Sensory regression120 minutes

Time to two segment regression

Motor block regression120 minutes

Time to Bromage 1 and Bromage 0

Time to maximum effect (Tmax)20 minutes

Time when the motor blockade is complete and sensory blockade is in at the level of T4 dermatome

Time to minimum effect (Tmin)120 minutes

Time to two segment regression of the sensory block (T6) and for motor block regression to Bromage1 and Bromage 0

Nausea0 hours, 2 hours, 4 hours, 8 hours, 24 hours postoperatively

Scale for nausea (0:no nausea 10:worst possible nausea)

Vomiting0 hours, 2 hours, 4 hours, 8 hours, 24 hours postoperatively

Number of vomits

Shivering0 hours, 2 hours, 4 hours, 8 hours, 24 hours postoperatively

Yes:shiver No:no shiver

Total ephedrine consumption60 minutes

Total ephedrine consumption intraoperatively

Total phenylephrine consumption60 minutes

Total phenylephrine consumption intraoperatively

Total atropine consumption60 minutes

Total atropine consumption intraoperatively

Umbilical cord ph15 minutes

Umbilical cord ph after delivery

Need for administration of antiemetic agent90 minutes

Need for administration of antiemetic agent intraoperatively

Neonate Apgar score5 minutes

Apgar score in the 1st and 5th minute after delivery of the neonate

Trial Locations

Locations (1)

Aretaieio Hospital, University of Athens

🇬🇷

Athens, Attiki, Greece

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