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Uterine AtonyPhase 3CALBLOCNCT05027048

Calcium Chloride for Prevention of Blood Loss During Intrapartum Cesarean Delivery

A Phase 3 study testing Calcium chloride in people with Uterine Atony and Uterine Atony With Hemorrhage, run by Stanford University at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality worldwide. Up to 80% of PPH is caused by uterine atony, the failure of the uterine smooth muscle to contract and compress the uterine vasculature after delivery. Read more about this study

Who is it for?
Ages 18 to 55 years, women only
What is being tested?
Calcium chloride
Type of treatment
Injection or infusion
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
120 participants
Where
1 siteUnited States
Study dates
4 Apr 2022to 3 Apr 2023
Phase
Phase 3
Are there results?
Yes, posted in the registrySummary in the doctors' view

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 55 years
  • Women only
  • No healthy volunteers
  • Adult

Who may be able to join

  • Patient had a trial of labor for vaginal delivery prior to cesarean
  • Patient received an oxytocin infusion for labor augmentation or induction prior to cesarean

Who cannot join

  • renal dysfunction with serum Cr >1.0 mg/dL
  • known underlying cardiac condition
  • treatment with digoxin within the last 2 weeks for a maternal or fetal indication
  • treatment with a calcium channel blocker medication within 24 hours
  • hypertension necessitating intravenous antihypertensive medication within 24 hours
  • emergent case in which study participation could in any way impede patient care by the judgement of the obstetrician, anesthesiologist, or bedside nurse

Trial locations and contacts

1 site in 1 country.

United States1 site

  • Jessica Ansari

    Pacifica, California, 94044

Other trials in United States

About this study

Official title: Calcium Chloride for Prevention of Blood Loss From Uterine Atony During Intrapartum Cesarean Delivery (CALBLOC): a Double Blind, Randomized, Placebo Controlled Trial and Nested Population Pharmacokinetic and Pharmacodynamic Analysis

Postpartum hemorrhage (PPH) is the leading cause of maternal morbidity and mortality worldwide. Up to 80% of PPH is caused by uterine atony, the failure of the uterine smooth muscle to contract and compress the uterine vasculature after delivery. Laboratory and epidemiological studies show that low extracellular and serum calcium levels, respectively, decrease uterine contractility. A pilot study performed by the investigators supports the hypothesis that intravenous calcium chloride is well tolerated and may have utility in preventing uterine atony. The proposed research will establish the relationship between uterine tone and calcium through a clinical trial with an incorporated pharmacokinetic and pharmacodynamic (PK/PD) study. In a randomized, placebo-controlled, double-blind trial, investigators will establish the effect of 1 gram of intravenous calcium chloride upon quantitative blood loss and uterine tone during cesarean delivery in parturients with high risk of uterine atony. Investigators will concurrently collect serial venous blood samples to measure calcium for PK/PD modeling in this pregnant study cohort. High-quality clinical research and development of novel therapeutics to manage uterine atony are critical to reduce the high maternal morbidity and mortality from PPH.

Being tested
Calcium chloride, Saline placebo
Keywords
calcium chloride, uterine atony, postpartum hemorrhage, cesarean delivery, intrapartum cesarean
Medical subject headings
Uterine Inertia, Postpartum Hemorrhage

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Calcium chlorideDrug

    See arm description above

  • Saline placeboDrug

    see arm description above

Study groups in NCT05027048
Study groupRoleWhat they receive
Calcium chlorideExperimental1 gram of calcium chloride in total volume 60mL with sterile saline, delivered over 10 minute controlled infusion at a constant rate (360mL/hour) beginning 2 minutes after fetal delivery and 1 minute after delayed cord clamp. This intervention occurs IN ADDITION TO standard care with oxytocin 2 unit bolus and infusion at 7.5 units per hour which begins immediately after fetal delivery.
Receives: Drug: Calcium chloride
Saline placeboPlacebo comparator60mL sterile saline, delivered over 10 minute controlled infusion at a constant rate (360mL/hour) beginning 2 minutes after fetal delivery and 1 minute after delayed cord clamp. This intervention occurs IN ADDITION TO standard care with oxytocin 2 unit bolus and infusion at 7.5 units per hour which begins immediately after fetal delivery.
Receives: Drug: Saline placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Quantitative Blood Loss

    Standardized volumetric and gravimetric assessment of blood loss during cesarean. Note: will analyze all participants, but planned subgroup analysis will also occur excluding patients with non-atonic reasons for blood loss including hysterotomy extension, placental abruption, cervical or vaginal laceration, etc

    Measured: measurement occurs at conclusion of operating room case

Secondary outcomes (14)

  1. Number of Participants With Postpartum Hemorrhage

    Postpartum hemorrhage was defined as quantitative blood loss > 1000 milliliters during operative course

    Measured: operative course (within 4-6 hours of fetal delivery)

  2. Number of Participants With Second Line Uterotonic Requirement

    Yes/no: did the patient require treatment with methylergonovine, carboprost, and/or misoprostol for uterine atony

    Measured: within 4 hours of delivery

  3. Number of Patients With a Transfusion Requirement

    Yes/no, if patient required transfusion of packed red blood cells prior to hospital discharge

    Measured: 96 hours of delivery

  4. Change in Hematocrit From Baseline

    Measured pre-delivery hematocrit minus measured post-operative day 1 hematocrit. Correction factor of 3 hematocrit points per unit packed red blood cells transfused

    Measured: 1 day

  5. Total Oxytocin Bolus Requirement

    Total dose oxytocin bolus during cesarean

    Measured: Cesarean duration, within 4-6 hours of fetal delivery

  6. Uterine Tone Numerical Rating Score, 7 Minutes After Fetal Delivery

    Uterine tone assessment: Obstetricians at the study institution use the following validated scale to grade uterine tone for all cesarean deliveries. The obstetrician places their hand directly on the uterine fundus and scores the adequacy of contraction. The interrater characteristics of this scale have been published (Cole et al, 2021).

    The scale ranges from 0-10. A score of 0 is the worst possible score and represents a flaccid, atonic uterus. A score of 10 is the best possible score and represents a firmly-contracted uterus.

    Measured: 7 minutes after fetal delivery, 5 minutes after initiating study drug infusion

  7. Uterine Tone Numerical Rating Score, 12 Minutes After Fetal Delivery

    Uterine tone assessment: Obstetricians at the study institution use the following validated scale to grade uterine tone for all cesarean deliveries. The obstetrician places their hand directly on the uterine fundus and scores the adequacy of contraction. The interrater characteristics of this scale have been published (Cole et al, PMID 33652161).

    The scale ranges from 0-10. A score of 0 is the worst possible score and represents a flaccid, atonic uterus. A score of 10 is the best possible score and represents a firmly-contracted uterus.

    Measured: 12 minutes after fetal delivery, 10 minutes after initiating study drug infusion

  8. Fluid Requirement

    Total crystalloid required during cesarean delivery in mL

    Measured: Operating room duration, usually 2 hours

  9. Percent Change in Mean Arterial Pressure

    Baseline mean arterial blood pressure recorded as average of first 6 mean arterial blood pressures recorded in operating room. Percent change calculated as measured mean arterial blood pressure minus baseline, divided by baseline. Reported here as the maximal decrease in mean arterial pressure. Repeated measures ANOVA reported in Statistical Analysis.

    Measured: every 5 minutes for 30 minutes after study drug infusion initiation, compared to baseline

  10. Percent Change in Heart Rate From Baseline

    Baseline heart rate recorded as average of first 6 heart rates recorded in operating room. Percent change calculated as measured heart rate minus baseline, divided by baseline. Maximal % increase in heart rate reported here. Repeated measures ANOVA used to analyze overall trend in Statistical Analysis below.

    Measured: every 5 minutes for 30 minutes after study drug infusion initiation, compared to baseline

  11. Total Phenylephrine Requirement

    Total phenylephrine in milligrams administered while in the operating room

    Measured: Duration of operating room time, up to 240 minutes

  12. Pharmacokinetics of Calcium Chloride - Baseline Ionized Calcium

    Measured using an Abbott istat machine and CG8+ cartridge to determine venous blood gas ionized calcium levels

    Measured: In the operating room prior to study drug administration (generally <30 minutes prior to fetal delivery and study drug administration)

  13. Pharmacokinetics of Calcium Chloride - Peak Change in Ionized Calcium From 1 Gram of Calcium Chloride

    Generated from a 2-compartment population pharmacokinetic model in NONMEM using serial venous blood gas ionized calcium concentrations.

    Measured: At Tmax (conclusion of the 10-minute intravenous calcium chloride infusion

  14. Pharmacodynamic Effect of Calcium Upon Uterine Tone NRS

    Data were not collected. This measure required blood specimens to be obtained at the time of tone scores and this was not done.

    Measured: Within 20 minutes of study drug administration

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted30 Aug 2021
  2. Study start4 Apr 2022
  3. Primary completion29 Mar 2023
  4. Study completion3 Apr 2023

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase 3
Primary purpose
Prevention
Allocation
Randomised
Intervention model
Parallel groups
Model description
Double blind, placebo controlled randomized clinical trial with 1:1 allocation
Masking
Quadruple blind
Who is masked
Participant, Care provider, Investigator, Outcomes assessor
Enrolment
120 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT05027048
Sponsor's protocol ID
62206
Other IDs
MRTG-02-15-2022-Ansari, YIG-2020
Acronym
CALBLOC
Status last verified
May 2024
First submitted
18 Aug 2021
Last updated
11 Jun 2024
Data monitoring committee
Yes
FDA-regulated drug
Yes
FDA-regulated device
No
Individual data sharing
No

Publications

  • Cole NM, Abushoshah I, Fields KG, Carusi DA, Robinson JN, Bateman BT, Farber MK. The interrater reliability and agreement of a 0 to 10 uterine tone score in cesarean delivery. Am J Obstet Gynecol MFM. 2021 May;3(3):100342. doi: 10.1016/j.ajogmf.2021.100342. Epub 2021 Feb 27.

    PubMed 33652161

  • Ansari JR, Yarmosh A, Michel G, Lyell D, Hedlin H, Cornfield DN, Carvalho B, Bateman BT. Intravenous Calcium to Decrease Blood Loss During Intrapartum Cesarean Delivery: A Randomized Controlled Trial. Obstet Gynecol. 2024 Jan 1;143(1):104-112. doi: 10.1097/AOG.0000000000005441. Epub 2023 Nov 3.

    PubMed 37917943

Questions about this trial

What is this clinical trial studying?

A Phase 3 study testing Calcium chloride in people with Uterine Atony and Uterine Atony With Hemorrhage, run by Stanford University at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 2 inclusion and 6 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 11 Jun 2024. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

What does this phase mean?

Phase 3 studies compare the treatment with the current standard treatment or a placebo in a large group, to confirm how well it works and watch for side effects.

Not every study follows the same path, and some studies (observational studies, device studies) have no phase.

Are results available for this study?

Yes. Results are posted in the registry (first posted 11 Jun 2024). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Quantitative Blood Loss (time frame: measurement occurs at conclusion of operating room case). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT05027048, which also lists 2 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 11 Jun 2024.

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