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Phenylephrine and Pulse Pressure Variability

Sponsor
University of Texas Southwestern Medical Center (Other)
Overall Status
Recruiting
CT.gov ID
NCT05011357
Collaborator
Texas Health Resources (Other)
6
Enrollment
1
Location
2
Arms
21.6
Anticipated Duration (Months)
0.3
Patients Per Site Per Month

Study Details

Study Description

Brief Summary

The purpose of this research study is to determine how vasopressors affect a measure of how intravenous fluid is administered in people undergoing surgery who have low blood pressure called Pulse Pressure Variability (PPV). This study will recruit human subjects to undergo simulated hypovolemia called Lower Body Negative Pressure (LBNP) and will receive phenylephrine and placebo, while PPV will be measured in both conditions. This research will help anesthesiologists learn more about how to use PPV in patients undergoing surgery and who need vasopressors.

Condition or Disease Intervention/Treatment Phase
Early Phase 1

Detailed Description

Perioperative fluid administration is a very important issue in modern anesthesia practice. Overzealous intraoperative administration of fluids can lead to cardiac overload thus potentially causing significant morbidity. It has been demonstrated that over 50% of perioperative complications are tied to intraoperative fluid administration and that changing intraoperative fluid management alone has significant positive benefit. Pulse pressure variation (PPV), which quantifies the respiratory variation in beat-to-beat arterial blood pressure, is viewed as a reliable method to assess volume status. Increasing PPV indicates hypovolemia, and a decreasing PPV indicates progression towards euvolemia. However, there are many commonly encountered intraoperative conditions that may make these interpretations of PPV problematic. For example it is commonly accepted in the perioperative community that PPV is interpretable in patients without vasopressor infusion since there is little consensus to the effects of vasopressor therapy on PPV. Hence the proposed study seeks to characterize the PPV response during simulated hypovolemia with and without infusion of phenylephrine, which acts on alpha-1 receptors to increase systemic vascular resistance, and hence blood pressure.

In a patient under general anesthesia, a PPV cut-off of 13% indicates a positive response to fluid administration. However, this cut-off was based on studies that used a wide variety of vasopressor agents with different mechanisms. Furthermore, it is unclear how effective the current threshold is at predicting fluid responsiveness when vasopressors are added during the same operation (i.e. a PPV of 13% without vasopressors likely represents different physiologic conditions compared to a PPV of 13% with vasopressors in the same operation). Hence, understanding how vasopressors such as phenylephrine change PPV and the PPV threshold is very important and represents an important knowledge gap in the practice of anesthesia.

Study Design

Study Type:
Interventional
Anticipated Enrollment :
6 participants
Allocation:
Randomized
Intervention Model:
Crossover Assignment
Masking:
Single (Participant)
Masking Description:
Single blind
Primary Purpose:
Basic Science
Official Title:
Effect of Phenylephrine Infusion on Pulse Pressure Variability
Actual Study Start Date :
Sep 10, 2021
Anticipated Primary Completion Date :
Dec 30, 2022
Anticipated Study Completion Date :
Jun 30, 2023

Arms and Interventions

Arm Intervention/Treatment
Experimental: Phenylephrine

Phenylephrine infusion (0.3 mcg/kg/hr)

Drug: Phenylephrine
Phenylephrine will be administered as an infusion
Other Names:
  • Phenylephrine infusion

    		•
    Placebo Comparator: Control

    Saline infusion

    Drug: Saline Control
    Saline infusion
    Other Names:
  • Saline

    		•

    Outcome Measures

    Primary Outcome Measures

    1. Pulse Pressure Variability [Thirty minutes following phenylephrine infusion]

      Quantifying respiratory variation in beat-to-beat arterial blood pressure

    Eligibility Criteria

    Criteria

    Ages Eligible for Study:
    18 Years to 45 Years
    Sexes Eligible for Study:
    All
    Accepts Healthy Volunteers:
    Yes
    Inclusion Criteria:

    • 18 to 45 years of age

    • Non-obese (Body Mass Index less than 30 kg/m2)

    • Baseline systolic blood pressure between 80-140 mmHg

    • Baseline diastolic blood pressure <90 mmHg

    Exclusion Criteria:

    • Participants who have cardiac, vascular, respiratory, neurological and/or metabolic illness

    • Current or previous use of anti-hypertensive medications

    • Any known history of renal or hepatic insufficiency/disease

    • Pregnancy (verified by negative urine test on the experimental days) or breast-feeding

    • Current smokers, as well as individuals who regularly smoked within the past 3 years

    • Sulfite allergy, as this is a contraindication to intravenous phenylephrine

    • Serious mental illness including claustrophobia

    • History of use of recreational drugs including cocaine or amphetamines

    • Peripheral vascular disease

    • Subject on anticoagulant treatment

    • Subjects with a baseline systolic blood pressure <80 mmHg

    Contacts and Locations

    Locations

    Site City State Country Postal Code
    1 Texas Health Resources Dallas Texas United States 75231

    Sponsors and Collaborators

    • University of Texas Southwestern Medical Center
    • Texas Health Resources

    Investigators

    • Principal Investigator: Noah Jouett, DO/PhD, University of Texas Southwestern Medical Center

    Study Documents (Full-Text)

    None provided.

    More Information

    Publications

    None provided.
    Responsible Party:
    Noah Jouett, Resident Anesthesiologist, University of Texas Southwestern Medical Center
    ClinicalTrials.gov Identifier:
    NCT05011357
    Other Study ID Numbers:
    • STU-2021-0497
    First Posted:
    Aug 18, 2021
    Last Update Posted:
    Feb 2, 2022
    Last Verified:
    Jan 1, 2022
    Individual Participant Data (IPD) Sharing Statement:
    No
    Plan to Share IPD:
    No
    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
    Keywords provided by Noah Jouett, Resident Anesthesiologist, University of Texas Southwestern Medical Center
    Phenylephrine
    Pulse pressure variation
    Additional relevant MeSH terms:
    Hypotension
    Phenylephrine
    Oxymetazoline

    Study Results

    No Results Posted as of Feb 2, 2022