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

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
Alex James Butwick, Stanford University
ClinicalTrials.gov Identifier:
NCT00788255
First received: November 6, 2008
Last updated: October 17, 2016
Last verified: October 2016
  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 Stanford University:

Primary Outcome Measures:
  • r Time [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    thromboelastographic indices - reaction time (normal range, 5-10 min)

  • k Time [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    thromboelastographic indices - clot formation time (normal range, 1-3 min)

  • Alpha Angle [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    thromboelastographic - alpha angle = clot formation rate (normal range, 53 degress to 72 degrees)

  • MA [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    thromboelastographic indices - maximum amplitude (normal range, 50-70 mm)

  • MRTG [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    thromboelastographic indices - maximum rate of thrombus generation (normal range, 5-17 mm/min)

  • Tmax [ Time Frame: 6 months ] [ Designated as safety issue: No ]
    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 ] [ Designated as safety issue: No ]
    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

Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Genders 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
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: 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 
Study First Received: November 6, 2008
Results First Received: February 3, 2016
Last Updated: October 17, 2016
Health Authority: United States: Institutional Review Board
Individual Participant Data  
Plan to Share IPD: No

Additional relevant MeSH terms:
Oxytocin
Oxytocics
Reproductive Control Agents
Physiological Effects of Drugs

ClinicalTrials.gov processed this record on December 02, 2016