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Phenylephrine and Pulse Pressure Variability

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ClinicalTrials.gov Identifier: NCT05011357
Recruitment Status : Recruiting
First Posted : August 18, 2021
Last Update Posted : February 17, 2023
Texas Health Resources
Information provided by (Responsible Party):
Noah Jouett, University of Texas Southwestern Medical Center

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
Intraoperative Hypotension Drug: Phenylephrine Drug: Saline Control 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.

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Study Type : Interventional  (Clinical Trial)
Estimated 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 : September 10, 2021
Estimated Primary Completion Date : June 30, 2024
Estimated Study Completion Date : June 30, 2024

Arm Intervention/treatment
Experimental: Phenylephrine
Phenylephrine infusion (0.3 mcg/kg/hr)
Drug: Phenylephrine
Phenylephrine will be administered as an infusion
Other Name: Phenylephrine infusion

Placebo Comparator: Control
Saline infusion
Drug: Saline Control
Saline infusion
Other Name: Saline

Primary Outcome Measures :
  1. Pulse Pressure Variability [ Time Frame: Thirty minutes following phenylephrine infusion ]
    Quantifying respiratory variation in beat-to-beat arterial blood pressure

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:

  • 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

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 ClinicalTrials.gov identifier (NCT number): NCT05011357

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Contact: Noah P Jouett, DO/PhD (214) 648-5460 noah.jouett@utsouthwestern.edu
Contact: David McDonagh, MD 214/648-8083 david.mcdonagh@utsouthwestern.edu

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United States, Texas
Texas Health Resources Recruiting
Dallas, Texas, United States, 75231
Contact: Noah P Jouett, DO/PhD         
Principal Investigator: Noah P Jouett, DO/PhD         
Sponsors and Collaborators
University of Texas Southwestern Medical Center
Texas Health Resources
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Principal Investigator: Noah Jouett, DO/PhD University of Texas Southwestern Medical Center
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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: August 18, 2021    Key Record Dates
Last Update Posted: February 17, 2023
Last Verified: February 2023
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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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
Keywords provided by Noah Jouett, University of Texas Southwestern Medical Center:
Pulse pressure variation
Additional relevant MeSH terms:
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Vascular Diseases
Cardiovascular Diseases
Cardiotonic Agents
Autonomic Agents
Peripheral Nervous System Agents
Physiological Effects of Drugs
Vasoconstrictor Agents
Nasal Decongestants
Respiratory System Agents
Adrenergic alpha-1 Receptor Agonists
Adrenergic alpha-Agonists
Adrenergic Agonists
Adrenergic Agents
Neurotransmitter Agents
Molecular Mechanisms of Pharmacological Action
Protective Agents