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Analgesics in the Pre-hospital Setting: Implications on Hemorrhage Tolerance - Morphine

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. Identifier: NCT04138615
Recruitment Status : Completed
First Posted : October 24, 2019
Results First Posted : January 12, 2023
Last Update Posted : January 12, 2023
Information provided by (Responsible Party):
Craig Crandall, University of Texas Southwestern Medical Center

Brief Summary:
We are examining how morphine (a commonly used pain medication) will alter responses to simulated blood loss in humans. To simulate blood loss in our research laboratory, participants will complete a test with their lower body in a custom-designed vacuum chamber for a brief period of time.

Condition or disease Intervention/treatment Phase
Healthy Drug: Morphine Other: Placebo Phase 1 Phase 2

Detailed Description:

Pain management on the battlefield is critical for the wellbeing of the soldier. Given that a hemorrhagic injury on the battlefield is virtually always associated with pain, it is paramount that the selected pain medication does not disrupt appropriate physiological mechanisms that are beneficial towards the maintenance of blood pressure and vital organ blood flow during that hemorrhagic insult. Current guidelines for the selection of pain medications of a hemorrhaging soldier are based upon limited scientific evidence, with the vast majority of supporting studies being conducted on anesthetized animals. Thus, the interaction between hemorrhagic shock and pain medications commonly employed on the battlefield is yet to be determined in the conscious humans.

With this background, we will test the hypothesis that morphine will impair the capacity for a conscious human to tolerate a hemorrhagic insult.

The obtained data will provide the necessary scientific evidence in humans to support the Committee on Tactical Combat Casualty Care (CoTCCC) guidelines on the analgesic of choice for moderate to severe injuries where the casualty is in hemorrhagic shock. Notably, such data will identify the analgesic that least compromises a human's ability to tolerate a hemorrhagic insult, ultimately providing critical information to the combat medic on which analgesic should be employed for such an injury.

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Study Type : Interventional  (Clinical Trial)
Actual Enrollment : 44 participants
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Single (Participant)
Primary Purpose: Basic Science
Official Title: Analgesics in the Pre-hospital Setting: Implications on Hemorrhage Tolerance - Morphine
Actual Study Start Date : November 12, 2019
Actual Primary Completion Date : January 4, 2022
Actual Study Completion Date : January 4, 2022

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Bleeding

Arm Intervention/treatment
Experimental: Morphine
Morphine will be administered intravenously
Drug: Morphine
Subjects will receive Morphine while the effects of this drug on tolerance to a hemorrhagic insult will be assessed.

Placebo Comparator: Placebo
Saline will be administered intravenously
Other: Placebo
Subjects will receive saline while the effects of this drug on tolerance to a hemorrhagic insult will be assessed.

Primary Outcome Measures :
  1. Tolerance to Simulated Hemorrhage [ Time Frame: 30 minutes from the onset of applying lower-body negative pressure ]
    Tolerance to a simulated hemorrhagic challenge will be assessed, for both the placebo and morphine limbs, by causing progressive central hypovolemia via lower-body negative pressure (LBNP). This progressive LBNP challenge will be performed until the onset of syncopal symptoms (defined as: profound bradycardia, a precipitous drop in arterial blood pressure and accompanying narrowing of pulse pressure, a sustained systolic blood pressure less than 80 mmHg, and/or subjective symptoms such as light-headedness, sweating, nausea, or dizziness). The primary variable will be the quantification of LBNP that is required to cause these symptoms. This quantification will be objectively measured via a cumulative stress index which is calculated as the sum of the product of the LBNP level and the duration of each level, until test termination (i.e., 40 mmHg x 3 min + 50 mmHg x 3 min, etc). A larger cumulative stress index represents a greater tolerance

Secondary Outcome Measures :
  1. Pain Assessment - Algometer [ Time Frame: 30 minutes from the onset of the protocol ]
    Pain assessments will be conducted using a digital algometer to obtain maximum pain thresholds caused by pressure. This pain assessment technique is conducted by applying the tip of a hand-held digital algometer on the subject's digit. Force is gradually increased and the peak force is recorded when the subject first reports a painful sensation. Removal of the pressure from the algometer immediately relieves the painful sensation and the subject can voluntarily stop the test at any time. This assessment will be performed when the subject has received placebo and morphine.

Information from the National Library of Medicine

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Ages Eligible for Study:   18 Years to 45 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • Healthy
  • Non-obese (body mass index less than 30 kg/m2)
  • Body mass greater than or equal to 65 kg

Exclusion Criteria:

  • Subjects who have cardiac, respiratory, neurological and/or metabolic illnesses
  • Any known history of renal or hepatic insufficiency/disease
  • Pregnancy or breast feeding
  • Current smokers, as well as individuals who regularly smoked within the past 3 years
  • Positive urine drug screen
  • Currently taking pain modifying medication(s)

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 identifier (NCT number): NCT04138615

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United States, Texas
University of Texas Southwestern Medical Center
Dallas, Texas, United States, 75390
Sponsors and Collaborators
University of Texas Southwestern Medical Center
  Study Documents (Full-Text)

Documents provided by Craig Crandall, University of Texas Southwestern Medical Center:
Informed Consent Form  [PDF] April 6, 2021

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Responsible Party: Craig Crandall, Professor of Internal Medicine, University of Texas Southwestern Medical Center Identifier: NCT04138615    
Other Study ID Numbers: STU 092017-070
First Posted: October 24, 2019    Key Record Dates
Results First Posted: January 12, 2023
Last Update Posted: January 12, 2023
Last Verified: December 2022
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: Undecided

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Studies a U.S. FDA-regulated Drug Product: Yes
Studies a U.S. FDA-regulated Device Product: No
Product Manufactured in and Exported from the U.S.: No
Additional relevant MeSH terms:
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Pathologic Processes
Analgesics, Opioid
Central Nervous System Depressants
Physiological Effects of Drugs
Sensory System Agents
Peripheral Nervous System Agents