We updated the design of this site on September 25th. Learn more.
Show more
ClinicalTrials.gov
ClinicalTrials.gov Menu

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

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT00788255
First Posted: November 10, 2008
Last Update Posted: November 28, 2016
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Information provided by (Responsible Party):
Alex James Butwick, Stanford University
  Purpose
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.

Condition Intervention
Anesthesia Drug: Final exogenous oxytocin concentration=22.5 μU/mL Drug: Final exogenous oxytocin concentration=30.1μU/mL Drug: Final exogenous oxytocin concentration=32.9μU/mL

Study Type: Observational
Study Design: Observational Model: Case-Only
Time Perspective: Prospective
Official Title: In-vitro Study to Assess the Coagulation Effects of Exogenous Oxytocin Using Thromboelastography.

Resource links provided by NLM:


Further study details as provided by Alex James Butwick, Stanford University:

Primary Outcome Measures:
  • r Time [ Time Frame: 6 months ]
    thromboelastographic indices - reaction time (normal range, 5-10 min)

  • k Time [ Time Frame: 6 months ]
    thromboelastographic indices - clot formation time (normal range, 1-3 min)

  • Alpha Angle [ Time Frame: 6 months ]
    thromboelastographic - alpha angle = clot formation rate (normal range, 53 degress to 72 degrees)

  • MA [ Time Frame: 6 months ]
    thromboelastographic indices - maximum amplitude (normal range, 50-70 mm)

  • MRTG [ Time Frame: 6 months ]
    thromboelastographic indices - maximum rate of thrombus generation (normal range, 5-17 mm/min)

  • 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)

  • TTG [ Time Frame: 6 months ]
    thromboelastographic indices - total thrombus generation (normal range, 584-796 mm)


Biospecimen Retention:   None Retained
Venous blood

Enrollment: 25
Study Start Date: October 2008
Study Completion Date: June 2009
Primary Completion Date: June 2009 (Final data collection date for primary outcome measure)
Groups/Cohorts Assigned Interventions
All participants

For each patient, 1 solution with citrated whole blood (control) and 3 solutions with citrated whole blood and exogenous oxytocin were prepared in separate vials using micropipettes as follows:

Citrated whole blood 1mL + 23μU oxytocin: final exogenous oxytocin concentration=22.5 μU/mL Citrated whole blood 1mL + 31μU oxytocin: final exogenous oxytocin concentration=30.1μU/mL Citrated whole blood 1mL + 34μU oxytocin: final exogenous oxytocin concentration=32.9μU/mL

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.

Drug: Final exogenous oxytocin concentration=22.5 μU/mL
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 Name: TEG
Drug: Final exogenous oxytocin concentration=30.1μU/mL
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 Name: TEG
Drug: Final exogenous oxytocin concentration=32.9μU/mL
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 Name: TEG

Detailed Description:
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.
  Eligibility

Information from the National Library of Medicine

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, Learn About Clinical Studies.


Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Sampling Method:   Non-Probability Sample
Study Population
healthy pregnant patients awaiting elective induction of labor or cesarean delivery.
Criteria

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.

  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00788255


Locations
United States, California
Stanford University School of Medicine
Stanford, California, United States, 94305
Sponsors and Collaborators
Stanford University
Investigators
Principal Investigator: Alexander J Butwick Stanford University
  More Information

Responsible Party: Alex James Butwick, Principle Investigator, Stanford University
ClinicalTrials.gov Identifier: NCT00788255     History of Changes
Other Study ID Numbers: SU-10242008-1327
First Submitted: November 6, 2008
First Posted: November 10, 2008
Results First Submitted: February 3, 2016
Results First Posted: October 18, 2016
Last Update Posted: November 28, 2016
Last Verified: October 2016
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

Additional relevant MeSH terms:
Oxytocin
Citric Acid
Oxytocics
Reproductive Control Agents
Physiological Effects of Drugs
Anticoagulants
Calcium Chelating Agents
Chelating Agents
Sequestering Agents
Molecular Mechanisms of Pharmacological Action