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Completed

NCT Number: NCT03898882

Pharmacokinetics of Oxytocin at Cesarean Delivery

The primary objective is to obtain data to inform the design of a population pharmacokinetic study of oxytocin after administration at CD as per standard institutional practice.

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Key information

Conditions

Postpartum Hemorrhage Female Urogenital Diseases and Pregnancy Complications Hemorrhage Obstetric Labor Complications Pathologic Processes Pathological Conditions, Signs and Symptoms Pregnancy Complications Puerperal Disorders Urogenital Diseases Uterine Hemorrhage

Age range

18 year–45 year

Sex eligibility

Female

Study type

Observational

Primary location

Washington University in St. Louis

St Louis, Missouri, 63110, United States

About this study

In this pilot study the investigators will compare plasma oxytocin concentrations measured in arterial and venous blood, after oxytocin administration at cesarean delivery, in order to assess the validity of venous samples. They will also measure oxytocinase to explore how levels vary around the time of delivery of the placenta and to assess the effect that this may have on the metabolism of oxytocin.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Term singleton pregnancy
  • Age 18-45 years of age
  • ASA classification 2 or 3
  • Scheduled cesarean delivery under neuraxial anaesthesia

Exclusion criteria

  • Age or ASA classification outside of inclusion criteria
  • Need for general anaesthesia
  • Absence of consent
  • Inability to communicate in English or other barrier to providing informed consent

Treatment and study plan

Oxytocin

Drug

PK measurements of oxytocin

Shore durometer

Device

The investigators will take serial readings from a digital durometer at the uterine fundus at 3, 6, 9 and 12 minutes following OXT administration to provide data that will inform an estimate of the timing of peak effect. Shore durometers measure the hardness of materials on a scale of 0-100 Shore Units (SU). Preliminary (unpublished) data provided a range of 10-56 SU after oxytocin administration at cesarean delivery. Durometer readings were also shown to correlate positively with the obstetrician's manual assessment of uterine contractility, which is traditionally used to determine the success or failure of uterotonic therapy.

Primary outcomes

  1. Arterial [OXT]

    Time frame: Scheduled samples during the first 30 minutes after oxytocin administration

    Concentration of oxytocin in arterial samples

  2. Venous [OXT]

    Time frame: Scheduled samples during the first 30 minutes after oxytocin administration

    Concentration of oxytocin in venous samples

Secondary outcomes

  1. Arterial [OXTase]

    Time frame: Scheduled samples during the first 30 minutes after oxytocin administration

    Concentration of oxytocinase in arterial samples

  2. Uterine tone

    Time frame: Scheduled measurements during the first 30 minutes after oxytocin administration

    Uterine tone measured using a Shore Durometer or assessed by obstetrician using numerical rating score (NRS, 0-10)

  3. Hypotension

    Time frame: Measured intraoperatively

    Incidence of systolic BP reduced by 20% from baseline

  4. Nausea & Vomiting

    Time frame: Recorded intraoperatively

    Incidence of nausea and vomiting

  5. EBL

    Time frame: Estimated at the end of surgery

    Estimated blood loss in milliliters

Sponsors and collaborators

Lead sponsor

Washington University School of Medicine

Other

Registry information

Official study title

The Pharmacokinetics of Oxytocin in Pregnant Women Undergoing Cesarean Delivery - a Feasibility Pilot Study

Acronym: Peacocks

Important dates

Study start
2019
Primary completion
2020
Study completion
2020
First posted
Apr 2, 2019
Registry last updated
May 7, 2020

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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