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Completed

NCT Number: NCT00788255

In-vitro Study to Assess the Coagulation Effects of Exogenous Oxytocin Using Thromboelastography.

Oxytocin is normally administered following delivery in pregnant patients to reduce postpartum bleeding by increasing uterine tone. It is unclear whether the use of intravenous oxytocin alters coagulation in pregnant patients. The purpose of the in-vitro study is to assess the coagulation changes of oxytocin in blood samples from pregnant patients using thromboelastrography (TEG). TEG is a point-of-care device which measures the viscoelastic properties of clot formation, and can provide rapid and detailed information about coagulation changes. We aim to collect blood samples from pregnant patients to assess the in-vitro effects of synthetic oxytocin on coagulation using TEG.

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Key information

Conditions

Anesthesia

Age range

18 year–40 year

Sex eligibility

Female

Study type

Observational

Primary location

Stanford University School of Medicine

Stanford, California, 94305, United States

About this study

All obstetric patients presenting for elective induction of labor or elective Cesarean delivery will be informed about the study prior to and on admission to the labor and delivery unit. Admission blood sampling will take place by venepuncture for the following analysis:TEG, PT, PTT, INR, Hct, Platelet count.The results of oxytocin influence on thromboelastogram parameters will be compared to a control. The control is an aliquot of parturient blood with no added oxytocin. Thromboelastography will be used to assess coagulation changes between control samples and blood samples with added oxytocin. The results will not be used to influence clinical management of any case.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

All obstetric patients with singleton pregnancies admitted to the labor and delivery unit at Lucile Packard Childrens Hospital awaiting elective induction of labor or elective Cesarean delivery. We will select 25 healthy ASA 1 patients with singleton pregnancies who are scheduled for uncomplicated elective induction of labor. Gestational age equal to or greater than 37 weeks.

Exclusion criteria

Patients with underlying coagulation disorders. Patients with thrombocytopenia. Patients with pregnancy-induced hypertension, pre-eclampsia. Patients admitted for non-elective cesarean section. Patients in active labor. Patients requiring the following medications prior to surgery: NSAIDS, aspirin, anticoagulants.

Patients with significant obstetric or medical disease. No patients <18 years of age will be recruited.

Treatment and study plan

Final exogenous oxytocin concentration=22.5 μU/mL

Drug

Citrated whole blood 1mL + 23μU oxytocin. After mixing by inversion 8-10 times, 360μL kaolin-activated blood of each study solution was pipetted into a plastic cup in a prewarmed Thromboelastograph® (37°C). Each sample was recalcified in a plastic cup with 10μL of CaCl2 6.45%, and TEG® analysis was commenced within 1 minute of reconstituted sample preparation.

Other names: TEG

Final exogenous oxytocin concentration=30.1μU/mL

Drug

Citrated whole blood 1mL + 31μU oxytocin. After mixing by inversion 8-10 times, 360μL kaolin-activated blood of each study solution was pipetted into a plastic cup in a prewarmed Thromboelastograph® (37°C). Each sample was recalcified in a plastic cup with 10μL of CaCl2 6.45%, and TEG® analysis was commenced within 1 minute of reconstituted sample preparation.

Other names: TEG

Final exogenous oxytocin concentration=32.9μU/mL

Drug

Citrated whole blood 1mL + 34μU oxytocin. After mixing by inversion 8-10 times, 360μL kaolin-activated blood of each study solution was pipetted into a plastic cup in a prewarmed Thromboelastograph® (37°C). Each sample was recalcified in a plastic cup with 10μL of CaCl2 6.45%, and TEG® analysis was commenced within 1 minute of reconstituted sample preparation.

Other names: TEG

Primary outcomes

  1. r Time

    Time frame: 6 months

    thromboelastographic indices - reaction time (normal range, 5-10 min)

  2. k Time

    Time frame: 6 months

    thromboelastographic indices - clot formation time (normal range, 1-3 min)

  3. Alpha Angle

    Time frame: 6 months

    thromboelastographic - alpha angle = clot formation rate (normal range, 53 degress to 72 degrees)

  4. MA

    Time frame: 6 months

    thromboelastographic indices - maximum amplitude (normal range, 50-70 mm)

  5. MRTG

    Time frame: 6 months

    thromboelastographic indices - maximum rate of thrombus generation (normal range, 5-17 mm/min)

  6. Tmax

    Time frame: 6 months

    thromboelastographic indices - time to initiation of clot formation plus time to achieve maximum rate of clot strength development (normal range, 6-12 min)

  7. TTG

    Time frame: 6 months

    thromboelastographic indices - total thrombus generation (normal range, 584-796 mm)

Sponsors and collaborators

Lead sponsor

Stanford University

Other

Registry information

Important dates

Study start
2008
Primary completion
2009
Study completion
2009
First posted
Nov 10, 2008
Registry last updated
Nov 28, 2016

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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