Endogenous Pain Facilitation and Inhibition in Postpartum Women

December 15, 2017 updated by: Wake Forest University
This study seeks to further understand these three observations - (1) that the time period surrounding childbirth accelerates recovery from pain after injury (2) that this likely reflects dampened facilitating mechanisms and exaggerated inhibitory mechanisms, and (3) that stress may interfere with this protection. In this study the investigators will compare women within 2 weeks of delivery to age matched controls and anticipate that pain inhibition is increased after delivery, pain facilitation is decreased, and that there is a relationship between these pain responses and the degree of pre-existing stress.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

Nearly half of the world's population experiences labor and delivery processes which are associated with microscopic or gross tissue injury to the mother. Since this experience is widespread and occurs relatively early in life, the psychosocial, medical, and financial consequences of chronic pain following childbirth could be enormous. Surprisingly, previous studies with long term follow up of new mothers have included pain as a secondary measure and / or have focused on prevalence of pain without determining whether pain predated delivery or even pregnancy itself. The investigators recently performed a long term follow up study of over 1,200 women, and noted that pain which began during the childbirth itself was surprisingly rare in comparison to other physical injuries. Additionally, two central factors hypothesized to confer risk of chronic pain after other injuries including surgery, pre-dating chronic pain and degree of tissue and nerve injury, contributed minimally to the acute and sub-acute pain after childbirth. These two observations, low incidence of chronic pain and minimal effect of degree of tissue injury and history of chronic pain on sub-acute pain, point towards a potential protective effect of pregnancy or delivery on the response to physical injury.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • North Carolina
      • Winston-Salem, North Carolina, United States, 27157
        • Wake Forest Baptist Medical Center

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Sampling Method

Probability Sample

Study Population

Healthy women 10-14 days postpartum following term vaginal delivery, who are breast feeding and age- and race- matched healthy, nonpregnant women, either nulliparous or at least 1 year beyond delivery.

Description

Inclusion Criteria:

  • female
  • 10-14 days postpartum, term vaginal delivery
  • breastfeeding (postpartum women)
  • health non-pregnant female (nulliparous or at least 1 year beyond delivery)

Exclusion Criteria:

  • Allergy to chili peppers
  • pregnant
  • pain medication (narcotic or non-narcotic) within 4 hours of study visit Average pain in the 24 hours preceding the study visit >3. Postpartum women that score >13 on the Edinburgh Postnatal Depression Scale

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
endogenous pain facilitation
Pain facilitation is studied by a simple test of applying over the counter capsaicin cream to the skin for only 30 min, then removing it and heating the skin to a non-noxious temperature.
endogenous pain inhibition
Pain inhibition is studied by a simple test of mild pain on one area of the body reducing response to a pain stimulus in another area.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Area of hyperalgesia will be the primary outcome measure
Time Frame: 40 minutes post capsaicin application
Hyperalgesia and allodynia on the skin of the forearm will be established by heating the forearm with a 4 cm2 Peltier controlled thermode (TSA®) to 45 degrees Celsius for 5 minutes. The investigators will then apply topical capsaicin (0.075% cream, Bioglan Pharmaceuticals) under an occlusive dressing at the same site as the thermal probe for 30 minutes. 40 minutes after removal of the capsaicin cream the site will be heated to 40 degrees Celsius for 5 minutes (rekindling) following the end of capsaicin application. The investigators will test skin sensations with the filament and cotton wisp after this heating.
40 minutes post capsaicin application
Percent reduction in degree of pain to the 49 degrees Celsius stimulus during the time the foot is immersed in the cold water
Time Frame: 15 minutes
Conditioned pain modulation will be induced by placing a foot in a container of circulating water maintained at 10 degrees Celsius for 90 seconds. Thirty seconds after the foot is placed into container of circulating water, the stimulus response to heat on the contralateral forearm will be measured using a 49 degrees Celsius stimulus for 5 seconds. The foot will then be withdrawn and warmed with warm blankets. The stimulus response to heat stimuli on the arm will be measured 5 and 15 min thereafter.
15 minutes

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Wake Forest University

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: James C. Eisenach, MD, Wake Forest University Health Sciences

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
April 1, 2013

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 5, 2017

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 5, 2017

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
April 25, 2013

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
April 25, 2013

First Posted (Estimate)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
April 30, 2013

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
December 19, 2017

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
December 15, 2017

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
December 1, 2017

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • IRB00022603

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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