Can heart rate predict low blood pressure during Caesarean section?
| ISRCTN | ISRCTN22948433 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN22948433 |
| Protocol serial number | 2013123 |
| Sponsor | South Tees Hospitals NHS Foundation Trust (UK) |
| Funder | South Tees Hospitals NHS Foundation Trust (UK) |
- Submission date
- 25/04/2014
- Registration date
- 06/05/2014
- Last edited
- 29/05/2020
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Pregnancy and Childbirth
Plain English summary of protocol
Background and Study aims
Spinal anaesthesia is the most frequently used anaesthetic for planned delivery of babies by Caesarean section. It allows women to be awake and pain free during the birth of their baby. It is usually safer than general anaesthesia and following the operation there is less pain, drowsiness and nausea than after general anaesthesia. A problem with spinal anaesthesia is that it often causes low blood pressure (hypotension) during the operation (in eight out of ten women) if measures are not taken to prevent it. This can cause mothers to feel nauseated, or to feel faint and dizzy during their
operation. It can also reduce delivery of oxygen to the baby. We routinely use measures to prevent hypotension, or to reduce its severity if it does occur. This includes giving fluid and a drug (phenylephrine) into a drip in the mothers arm. Despite these efforts, approximately two out of ten women still develop hypotension in our hospital (the James Cook University Hospital) before delivery of the baby.
The aim of the study is to find if the heart rate just after the spinal anaesthetic has started can predict how low the blood pressure will go during the operation. We will study whether higher heart rates just after the spinal injection are associated with lower blood pressures as the spinal anaesthetic progresses.
Who can participate?
We plan to study 111 healthy women aged > 17 years undergoing planned Caesarean section under spinal anaesthesia in our hospital.
What does the study involve?
Women scheduled for Caesarean section at our hospital will be informed about the study when they attend the pre-operative clinic. On the day of operation, following informed consent, women will receive routine spinal anaesthesia and monitoring of blood pressure and heart rate. The study will last from the start of the spinal anaesthetic until delivery of the baby. Treatment and monitoring will be the same as for those not taking part in the study.
What are the possible benefits and risks of taking part?
The will be no additional risks because treatment will be the same as for those who do not take part. There will be no benefits from taking part. Future patients may benefit from our observations if they allow us predict which patients are most likely to develop hypotension during spinal anaesthesia for Caesarean section.
Where is the study run from?
The study will be run from the James Cook University Hospital in Middlesbrough (UK), which
is the only hospital taking part.
When is the study starting and how long is it expected to run for?
The study will start in May 2014 and continue for approximately 8 12 months.
Who is funding the study?
The South Tees Hospitals NHS Foundation Trust, Middlesbrough (UK).
Who is the main contact?
Dr David William Cooper, Consultant Anaesthetist
drdavidcooper@aol.com
Contact information
Scientific
Dept. of Anaesthesia
Cheriton House
James Cook University Hospital
Marton Road
Middlesbrough
Cleveland
TS4 3BW
United Kingdom
| drdavidcooper@aol.com |
Study information
| Primary study design | Observational |
|---|---|
| Study design | Single centre observational cohort study |
| Secondary study design | Cohort study |
| Study type | Participant information sheet |
| Scientific title | An observational study of the association between heart rate in the early post-spinal period and the lowest arterial pressure recorded during planned Caesarean section |
| Study objectives | That during spinal anaesthesia for Caesarean section there is an inverse association between early post-spinal heart rate and the lowest arterial pressure recorded between induction of spinal anaesthesia and delivery of the baby. |
| Ethics approval(s) | NRES Committee North East - Newcastle & North Tyneside 1, 05/01/2014, ref: 13/NE/0168 |
| Health condition(s) or problem(s) studied | Hypotension during spinal anaesthesia for Caesarean section |
| Intervention | Patients undergoing planned Caesarean section will receive routine spinal anaesthesia, monitoring, and preventative measures for hypotension and nausea during anaesthesia. The study will last from the induction of spinal anaesthesia until the delivery of the baby (duration approximately 20 30 minutes). The standard spinal anaesthetic is 2.8 ml of hyperbaric bupivacaine 0.5% combined with 400 µg of diamorphine in 0.4 ml. Routine monitoring is with an electrocardiogram, non-invasive blood pressure and pulse oximetry. Maternal arterial pressure will be measured every two minutes following induction of spinal anaesthesia. Intravenous Hartmanns solution will be given during the spinal anaesthetic. Intravenous ondansetron will be given immediately before spinal anaesthesia as nausea prophylaxis. An intravenous infusion of phenylephrine will be commenced at 67 µg/min at the time of the spinal injection and titrated to maintain arterial pressure close to the baseline pre-operative value. |
| Intervention type | Other |
| Primary outcome measure(s) |
1. Association between the heart rate at 3-minutes post-spinal and the lowest arterial pressure recorded during spinal anaesthesia before delivery of the baby |
| Key secondary outcome measure(s) |
1. A comparison of the heart rate at 3-minutes post spinal for those patients that develop nausea before delivery of the baby compared with those that do not |
| Completion date | 01/01/2015 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Sex | Female |
| Target sample size at registration | 111 |
| Key inclusion criteria | 1. Healthy women scheduled for elective Caesarean section under spinal anaesthesia 2. Singleton fetus, at least 36 weeks gestation, with no known abnormality 3. Under the care of a specialist Obstetrician at the James Cook University Hospital who consents to his/her patients being included in the trial 4. Patients giving informed consent to participate in the trial |
| Key exclusion criteria | 1. Pregnancy induced hypertension 2. Essential hypertension 3. Baseline systolic arterial pressure >145 mmHg, even if there is no history of hypertension 4. Diabetes 5. Age below 18 years 6. BMI over 45 at term 7. Anaesthetist is unable to perform spinal anaesthesia, spinal anaesthesia alone is not considered adequate for surgery to start, or general anaesthesia is required before delivery of the baby 8. Withdrawal of patients or obstetricians consent |
| Date of first enrolment | 01/05/2014 |
| Date of final enrolment | 01/01/2015 |
Locations
Countries of recruitment
- United Kingdom
- England
Study participating centre
TS4 3BW
United Kingdom
Results and Publications
| Individual participant data (IPD) Intention to share | No |
|---|---|
| IPD sharing plan summary | Not provided at time of registration |
| IPD sharing plan |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| HRA research summary | 28/06/2023 | No | No | ||
| Participant information sheet | Participant information sheet | 11/11/2025 | 11/11/2025 | No | Yes |
Editorial Notes
29/05/2020: No publications found.
07/02/2017: No publications found in PubMed, verifying study status with principal investigator.
