Method for prevention of oxytocin-induced hypotension in caesarean delivery by mixing of phenylephrine with oxytocin

ISRCTN ISRCTN71886984
DOI https://doi.org/10.1186/ISRCTN71886984
Secondary identifying numbers N/A
Submission date
04/03/2012
Registration date
04/04/2012
Last edited
18/09/2014
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Pregnancy and Childbirth
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
After a baby is delivered by caesarean section, a drug called Oxytocin (which helps the uterus to contract and reduces bleeding) is administered. Unfortunately, this drug has side effects, one of which is lowering blood pressure temporarily. The effect of this drop in blood pressure can be counteracted by administering another drug called Phenylephrine. We are investigating if giving both of these drugs together will reduce or prevent this fall in blood pressure.

Who can participate?
Any woman aged between 18 and 35 years undergoing elective caesarean section under spinal anaesthesia.

What does the study involve?
Participants will be randomly allocated into one of three groups. One group will receive oxytocin plus saline solution, the second group will get oxytocin plus 100 micrograms of Phenylephrine, and the third group will get oxytocin plus 200 micrograms of Phenylephrine. After the delivery of the baby, the medication will be administered and blood pressure will be measured every minute for five minutes. If the blood pressure drops in any of the groups, phenylephrine is given as appropriate.

What are the possible benefits and risks of participating?
The information and data collected from this study will help us to find the best way to prevent the drop in blood pressure caused by Oxytocin, hence improving care for women undergoing caesarean sections. Both drugs in this study are not new or experimental. They are being used routinely worldwide. We are only modifying the way we use them. The only discomfort that the patient may feel is the repeated blood pressure measurement on your arm every minute initially.

Where is the study run from?
Raja Isteri Pengiran Anak Saleha (RIPAS) Hospital, Brunei.

When is the study starting and how long is it expected to run for?
The study ran from October 2011 to September 2012.

Who is funding the study?
Ministry of Health and RIPAS hospital, Brunei.

Who is the main contact?
Dr A.B.M. Kamrul Hasan
drkamrul@dhaka.net

Contact information

Dr ABM Kamrul Hasan
Scientific

27-B, Mabohai Apartment
Simpang 10
Jalan Jawatan Dalam
Bandar Seri Begawan
BA 1111
Brunei Darussalam

Phone +673 (0) 868 4579
Email drkamrul@dhaka.net

Study information

Study designProspective randomised double-blind control study
Primary study designInterventional
Secondary study designRandomised controlled trial
Study setting(s)Hospital
Study typePrevention
Participant information sheet Not available in web format, please use the contact details below to request a patient information sheet
Scientific titlePrevention of oxytocin-induced hypotension in caesarean delivery by co-administration of phenylephrine with oxytocin: a prospective randomised double-blind controlled study
Study objectivesCo-administration of phenylephrine with oxytocin will reduce the incidence of oxytocin-induced hypotension after caesarean delivery.
Ethics approval(s)Medical and Health Research & Ethics Committee, Ministry of Health, Brunei Darussalam, 16/06/2011, ref: MHREC/MOH/ 2011/9 (7)
Health condition(s) or problem(s) studiedElective caesarean section under spinal anaesthesia
InterventionAfter written informed consent of the patients, 200 ASA class I and ll women having elective caesarean section under spinal anaesthesia will be given either a dose of 10 IU Oxytocin plus placebo or 10 IU Oxytocin plus 100 or 200 mcg of phenylephrine in a prospective, randomised double-blind fashion. Randomisation will be done by using Microsoft Excel generated random number allocations. Opaque envelopes containing group assignments will be used to ensure blinding of the investigators. The study and control medicine will be prepared before surgery and will be diluted with 0.9% normal saline up to a volume of 3 ml by an anaesthetist not involved in the study.

In the preoperative period, a large bore IV canula will be inserted. All patients will receive 500 ml of Haemaccele within before 30 minutes of spinal anaesthesia. Before spinal anaesthesia, standard monitoring (Datex Engstrom A/S 3, Helsinki, Finland) - Electrocardiogram (ECG), Non-Invasive Blood Pressure (NIBP) and Pulse Oximetry will be commenced. Measurement of NIBP and heart rate will be taken at 1 minute intervals from the time of oxytocin administration to next 5 minutes, and thereafter at 5 minutes intervals until the end of surgery. The last measurement of NIBP and heart rate before oxytocin administration will be considered as the baseline for subsequent changes.

Spinal anaesthesia will be performed at the L3-4 interspace with the patient in the sitting position. All subjects will be given 2 ml of 0.5% Bupivacaine Heavy plus 25 mcg of Fentanyl delivered through a 25 gauge sprotte needle with introducer to achieve uniform performance. The protocol medicine will be administered as an IV bolus over a time period of 5 to 10 seconds after clamping of the umbilical cord and delivery of the fetus. Immediately after the bolus, a separate infusion of oxytocin 20 IU in 500 ml of 0.9% normal saline will be continue over a 4-hour period (at the rate of 5 IU per hour).

Hypotension will be defined as a systolic blood pressure of less than 20% of the baseline blood pressure. Tachycardia will be defined as a maternal heart rate of more than 120 beats per minute. Crystalloid solution (Lactated Ringers Solution) will be infused during the intraoperative period with the aim of using a total crystalloid fluid of 1 litre. Each hypotension will be treated with an IV bolus of phenylephrine and both hypotensive episode and intraoperative fluid management will be at the discretion of the supervising anaesthetist who will not be involved in this study.

GROUPING OF THE PATIENTS:
Group A: Control group: 10 IU of Bolus Oxytocin plus Placebo
Group B: Study group: 10 IU of Bolus Oxytocin plus 100 mcg of Phenylephrine
Group C: Study group: 10 IU of Bolus Oxytocin plus 200 mcg of Phenylephrine
Intervention typeDrug
Pharmaceutical study type(s)
PhaseNot Applicable
Drug / device / biological / vaccine name(s)Oxytocin, phenylephrine
Primary outcome measurePercentage drops in blood pressure (BP) below 20% of baseline after intravenous injection of oxytocin in each arm of study
Secondary outcome measuresPercentage of patient having nausea and vomiting after oxytocin in each arm of study
Overall study start date01/10/2011
Completion date30/09/2012

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexFemale
Target number of participants200
Key inclusion criteria1. American Society of Anesthesiologists (ASA) class l and ll undergoing elective caesarean section
2. Age between 18 to 35 years
3. Body mass index (BMI) less than 35 kg/m2
4. Spinal anaesthesia
Key exclusion criteria1. Placenta previa
2. Thrombocytopenia
3. Coagulopathies
4. Previous major obstetrics haemorrhage (more than 1000 ml)
5. Known fibroid
6. Receiving anticoagulant therapy
7. Anemia (hemoglobin less than 9 g/dl)
8. Body mass index greater than 35 kg/m2
9. Preeclampsia
10. Cardiac, respiratory and renal disease
11. Known allergy to any protocol medicine
Date of first enrolment01/10/2011
Date of final enrolment30/09/2012

Locations

Countries of recruitment

  • Brunei Darussalam

Study participating centre

27-B, Mabohai Apartment
Bandar Seri Begawan
BA 1111
Brunei Darussalam

Sponsor information

Ministry of Health (Brunei)
Government

Commonwealth Drive
Bandar Seri Begawan
BB 3910
Brunei Darussalam

Website http://www.moh.gov.bn

Funders

Funder type

Government

Ministry of Health (Brunei)

No information available

Raja Isteri Pengiran Anak Saleha Hospital (RIPAS) Hospital (Brunei)

No information available

Results and Publications

Intention to publish date
Individual participant data (IPD) Intention to shareNo
IPD sharing plan summaryNot provided at time of registration
Publication and dissemination planNot provided at time of registration
IPD sharing plan