Oxytocin Maintenance Infusion in Labouring Women Undergoing Cesarean Delivery: an Up-down Sequential Allocation Study
For patients and families
In plain language
An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.
- What is being studied
- The protocol lists: Oxytocin.
- Who it may be relevant to
- Registry conditions: Postpartum Hemorrhage. Basic parameters: 18 years — 50 years · Female.
- What needs checking
- Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
- Where it takes place
- Canada
- Next step
- Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →
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Overview
This study is designed to determine the minimal effective oxytocin maintenance infusion required in labouring women undergoing cesarean delivery to achieve the best effect. Oxytocin is a drug that is routinely used to help the uterus to contract and keep it contracted after delivery. Consequently, it will help to reduce blood loss after delivery. In order to determine the minimal effective dose, the investigators will conduct a dose-finding study. The first patient will receive a set oxytocin infusion. The next patient's infusion dose of oxytocin, will either increase or decrease, depending on how the previous patient responds in terms of uterine tone. If the response is satisfactory with the infusion dose used, the next patient will either receive the same infusion dose or it will be decreased depending on a probability of 1:9. If the response is not satisfactory, then the infusion dose will increase for the next patient. The dose for each patient will be determined based on the results of the uterine contraction of the previous patient. The investigators hypothesize that the ED90 of the oxytocin infusion rate to maintain adequate uterine tone in labouring women with induced or augmented labour undergoing cesarean delivery, following an initial effective bolus dose, would be lower than 0.74 IU/min (44 IU/h), which was found as the ED90 in a previous study, without an initial bolus dose prior to the infusion.
Detailed description
This study will be conducted as a prospective, double blinded clinical trial (patient, anesthesiologist and obstetrician blinded to the oxytocin dose), in an up-down sequential allocation fashion. The objective of the study is to determine the minimum effective dose of oxytocin infusion required to produce appropriate uterine contraction during and after cesarean delivery under neuraxial anesthesia in laboring women. For the purpose of this study, the minimum effective dose is defined to be that at which adequate response occurs in 90% of patients, i.e. ED90.
Interventions
- Drug Oxytocin
Oxytocin will be prepared in a 1L bag of Ringer's lactate, to be infused at a rate of 125 ml/h.
Primary outcome measures
- Uterine tone up to discharge from the post anesthetic care unit (PACU): questionnaire [Time frame: 2 hours]
Secondary outcome measures (12)
- Calculated blood loss [Time frame: 24 hours]
- Need for blood transfusion [Time frame: 24 hours]
- Episodes of bleeding postpartum [Time frame: 24 hours]
- Intraoperative requirement for additional uterotonic medication [Time frame: 1 hour]
- Requirement for additional uterotonic medication in the PACU [Time frame: 2 hours]
- Requirement for additional uterotonic medication from discharge from the PACU until 24 hours postpartum. [Time frame: 24 hours]
- Hypotension: systolic blood pressure less than 80% of baseline [Time frame: 2 hours]
- Hypertension: systolic blood pressure greater than 120% of baseline [Time frame: 2 hours]
- Tachycardia: heart rate greater than 130% of baseline [Time frame: 2 hours]
- Bradycardia: heart rate less than 70% of baseline [Time frame: 2 hours]
- Presence of ventricular tachycardia: ECG [Time frame: 2 hours]
- Presence of atrial fibrillation: ECG [Time frame: 2 hours]
Eligibility criteria
Inclusion criteria
- All patients with induced or augmented labour undergoing cesarean delivery under neuraxial anesthesia (at least 3 hours of prior exposure to oxytocin during labour)
Exclusion criteria
- All patients who refuse to give written informed consent
- All patients who declare allergy or hypersensitivity to oxytocin
- A history of hypertension and/or severe cardiac disease(s)
- All patients who have contraindications for neuraxial anesthesia
- All patients who will be converted to general anesthesia intraoperatively
- All patients with placenta previa and multiple gestation
Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.
Healthy volunteers: Yes
Study design
- Allocation
- Non-randomized
- Model
- Parallel assignment
- Masking
- Quadruple blind
- Primary purpose
- Treatment
Study locations
Canada · 1 center
- Mount Sinai Hospital — Toronto
Identifiers
NCT: NCT05290129 · 22-02