Ephedrine vs Phenylephrine - ECG Changes

The recruitment status of this study is unknown because the information has not been verified recently.
Verified November 2010 by University College London Hospitals.
Recruitment status was  Not yet recruiting
Sponsor:
Collaborator:
Obstetric Anaesthetists' Association
Information provided by:
University College London Hospitals
ClinicalTrials.gov Identifier:
NCT01243970
First received: November 18, 2010
Last updated: December 2, 2010
Last verified: November 2010
  Purpose

ECG changes during caesarean section are common. Incidence of ST depression on the ECG is up to 81% in some studies. Although this may indicate inadequate oxygen supply to the heart muscle (myocardial ischaemia) many other theories have been suggested including air entering the circulation from the placental bed, high heart rate, hormone or nervous system influences and spasm of the coronary blood supply. Perioperative ST depression often reflects an imbalance between heart muscle oxygen supply and demand. At the time of delivery, high heart rate is common and there is a further increase in the amount of blood the heart has to pump every minute due to blood coming back to the circulation from the placental bed. This increases oxygen demand and most ST changes are seen at the time of delivery or within 30 minutes. The clinical significance of these changes is much debated, and apart from a few case reports do not appear to be associated with poor heart muscle function or ischaemia (lack of oxygen supply). Management of the mother's blood pressure during caesarean section has changed greatly in recent years. Intermittent boluses of ephedrine, given when blood pressure is low, have been replaced with prevention of low blood pressure and phenylephrine has become the drug of choice. Ephedrine increases heart rate and contractility of the heart muscle and is likely to increase oxygen demand. Phenylephrine reduces heart rate while maintaining blood pressure which may result in a more favorable oxygen supply demand ratio.

The investigators aim to compare the incidence of ECG changes if the mother's blood pressure is maintained with phenylephrine as compared to ephedrine. To see if these ECG changes are associated with myocardial ischaemia, the investigators will perform troponin T analysis after delivery. Troponin T is a molecule released by ischaemic heart muscle.


Condition Intervention Phase
Spinal Anesthesia
Pregnancy
Drug: Phenylephrine
Drug: Ephedrine
Phase 4

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Safety Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Treatment
Official Title: Randomised, Double-blind, Phase IV Study to Compare the Incidence of ECG Changes During Elective Caesarean Section Under Spinal Anaesthesia When Using Phenylephrine or Ephedrine Infusion to Maintain Baseline Systolic Blood Pressure

Resource links provided by NLM:


Further study details as provided by University College London Hospitals:

Primary Outcome Measures:
  • ST segment changes on Holter monitoring [ Time Frame: 30 minutes pre spinal anaesthesia to 4 hours post delivery ] [ Designated as safety issue: No ]

Secondary Outcome Measures:
  • Troponin levels [ Time Frame: 24h post delivery ] [ Designated as safety issue: No ]
  • Incidence of maternal low systolic blood pressure [ Time Frame: 20 minutes post spinal and 30 minutes post delivery ] [ Designated as safety issue: No ]
  • Maternal cardiac output [ Time Frame: 20 minutes post spinal and one measure at 5 minutes post delivery ] [ Designated as safety issue: No ]

Estimated Enrollment: 220
Arms Assigned Interventions
Active Comparator: phenylephrine infusion Drug: Phenylephrine

Infusion dose 50 mcg / minute. On/off regimen in response to blood pressure (BP) readings every minute. Approximative 30 minutes treatment duration. Total dose 50 mcg - 1500 mcg *

* We will start the infusion after the spinal anaesthetic (see trial design), and while we will monitor cardiac output and BP (for 20 minutes) the surgeons will prep the patient (surgery not started yet). Birth should occur more or less 10-15 minutes after beginning surgery, so this is approximatively 30 minutes after spinal anaesthetic. It is very unlikely that the infusion will run continuously and exceed 1500 mcg.

Active Comparator: Ephedrine infusion Drug: Ephedrine

Infusion dose 4mg / minute. On/off regimen in response to blood pressure readings every minute. Approximative 30 minutes treatment duration. Total dose 4 mg - 120 mg. *

* We will start the infusion after the spinal anaesthetic(see trial design), and while we will monitor cardiac output and BP (for 20 minutes) the surgeons will prep the patient (surgery not started yet). Birth should occur more or less 10-15 minutes after beginning surgery, so this is approximatively 30 minutes after spinal anaesthetic. It is very unlikely that the infusion will run continuously and exceed 120mg.


  Eligibility

Ages Eligible for Study:   16 Years and older
Genders Eligible for Study:   Female
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  1. Able to give written informed consent
  2. >37/40 weeks gestation
  3. Singleton pregnancy
  4. Elective caesarean section under spinal anaesthesia
  5. In good general health (American Society of Anesthesiology Category 1 or 2, fit and well or with mild systemic disease that has no impact on physical activity )

Exclusion Criteria:

  1. Circulatory disease (eg pre-existing hypertension)
  2. Cardiac disease/medications (e.g. angina, cardiomyopathy, B Blocker medication)
  3. Pregnancy related disease (eg pre-eclampsia)
  4. Diabetes pre-existing the pregnancy
  5. Hyperthyroidism
  6. Renal Disease
  7. Closed-angle glaucoma
  8. Patients on monoamine oxidase inhibitors
  9. In active labour
  10. Emergency caesarean section
  11. Fetal abnormalities
  12. Contraindications to spinal anaesthesia
  13. Height >6 feet/180cm / Height <5 feet/150cm
  14. Body mass index (BMI) <19 or >35
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01243970

Contacts
Contact: Roshan Fernando, FRCA 011 44 8451 555 000 r.fernando@btinternet.com

Locations
United Kingdom
University College London Hospital Not yet recruiting
London, United Kingdom, NW1 2BU
Contact: Roshan Fernando, FRCA    011 44 8451 555 000    r.fernando@btinternet.com   
Sponsors and Collaborators
University College London Hospitals
Obstetric Anaesthetists' Association
Investigators
Principal Investigator: Roshan Fernando, FRCA University College London Hospital
  More Information

No publications provided

Responsible Party: Alison J. Evans, Clinical coordinator, Joint UCLH/UCL Biomedical Research and Development (R&D) Unit
ClinicalTrials.gov Identifier: NCT01243970     History of Changes
Other Study ID Numbers: 08/0182
Study First Received: November 18, 2010
Last Updated: December 2, 2010
Health Authority: United Kingdom: Medicines and Healthcare Products Regulatory Agency

Keywords provided by University College London Hospitals:
Spinal anaesthesia
phenylephrine
ephedrine
ECG changes
Caesarean delivery
Myocardial ischaemia
Cardiac output
hypotension

Additional relevant MeSH terms:
Phenylephrine
Oxymetazoline
Ephedrine
Pseudoephedrine
Cardiotonic Agents
Cardiovascular Agents
Therapeutic Uses
Pharmacologic Actions
Mydriatics
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Sympathomimetics
Vasoconstrictor Agents
Nasal Decongestants
Respiratory System Agents
Adrenergic alpha-1 Receptor Agonists
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents
Central Nervous System Stimulants
Central Nervous System Agents
Bronchodilator Agents
Anti-Asthmatic Agents

ClinicalTrials.gov processed this record on October 19, 2014