Does Circumferential Negative Pressure Therapy Impair Distal O2 Saturation?

Study Overview
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Brief Summary
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Abstract: Background: Circumferential negative pressure wound therapy (CNPWT) is commonly used to manage wounds and enhance the healing process. A theoretical concern was recently raised that CNPWT may have a negative effect on perfusion distally. Objectives: We aim to evaluate the effect of circumferential negative pressure therapy (CNPT) on distal O2 saturation in healthy volunteers. Design: Randomized controlled non-inferiority study. Methods: Fourteen healthy adult volunteers with O2 saturation ≥95% (by index finger pulse oximetry) will be invited to participate in the study. After obtaining a written informed consent, CNPWT foam/dressing will be applied in a sandwich-like manner on the middle third of each arm and a negative intermittent pressure of 125 mmHg will be applied to one arm chosen randomly, using the contralateral arm as control. The pressure will be applied 5 minutes on and 2 minutes off for 9 hours. Individual's participation will be terminated if O2 saturation drops below 92% at any study time. The outcome measure is index finger O2 saturation and will be checked every 30 minutes using a pulse oximetry. The area under the curve (AUC) of O2 saturation in the 2 arms will be compared using ANCOVA. Sample size was calculated to have 90% power, assuming a type one error of 5%, non-inferiority margin of 24 (mean AUC difference), SD of 20, and drop out of 2 participants. Importance: The study is expected to provide conclusive evidence on the effect of intermittent CNPT on distal O2 saturation. The results would have direct implications for CNPWT.

Detailed Description
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The aim of this study is to evaluate the effect of circumferential negative pressure therapy (CNPT) on distal O2 saturation in healthy volunteers. Design and Methodology: Design: This is a randomized controlled non-inferiority study. Recruitment: Volunteers will be recruited through advertisement in King Faisal Specialist Hospital & Research Centre and other hospitals in Riyadh. Pre-study procedures: After obtaining a well documented medical history each volunteer will undergo a full physical examination as well as an in-depth upper limb examination and comprehensive evaluation (including a pre-study index finger O2 saturation and upper limbs circumference measurements), the following data will be also collected: age, sex, height&weight, body mass index, and vital signs. Procedures: CNPWT foam and dressing (in accordance to manufacturer's instructions) will be applied in a sandwich-like manner on the middle third of each arm, and a negative intermittent pressure of 125 mmHg will be applied to one arm chosen randomly, using the contralateral arm as control. The pressure will be applied 5 minutes on and 2 minutes off for 9 hours. Individual's participation will be terminated if O2 saturation by pulse oximetry drops below 92% at any study time. Statistical analysis: The area under the curve (AUC) of O2 saturation will be compared between the 2 arms using ANCOVA. Randomization schedule: a randomization schedule will be generated by an online program (www.randomization.com). Block randomization will be used. Sample size: Fourteen adult volunteers will be invited to participate in the study. The sample size for the study was calculated to have 90% power, assuming a type one error of 5%, non-inferiority margin of 24 (mean AUC difference), SD of 20, and drop out of 2 participants.

Official Title
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Does Circumferential Negative Pressure Therapy Impair Distal O2 Saturation? A Randomized Controlled Study

Conditions
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Negative Pressure Wound Therapy, Wound

Intervention / Treatment
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* Device: Negative Pressure System


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy adult volunteers with O2 saturation ≥95% by pulse oximetry. Potential volunteers will be screened by routine medical history and physical examination and an in-depth upper limb examination Exclusion Criteria: Unhealthy individual Chronic conditions History of upper limb diseases or defects. History of upper limb Surgical intervention. History of upper limb implants. Pre-study O2 saturation in either indices of less than 95% Congenital or Traumatic upper limb defect

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Parallel Assignment
Interventional Model Description: 2 groups: intervention and control (both are in each arm of the same participant). Intervention will be applied at one arm (chosen randomly) with using the contralateral arm as a control.
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Negative pressure<br>Negative pressure system is applied with negative pressure (Active) at a participant's unilateral arm | Device: Negative Pressure System<br>* Negative Pressure System is a non-invasive system that applies sub-atmospheric(Negative) pressure, through a foam and an air-tight film dressing which is connected by suction tubes to a controller unit by which the primary negative pressure can be adjusted.<br>|
| No Intervention: No negative pressure<br>Negative pressure system is applied without negative pressure (Inactive) at a participant's contralateral arm | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Area under the curve (AUC) of index finger O2 saturation over 9 hours. | Index finger O2 saturation will be checked every 30 minutes using a pulse oximetry, from zero hour of the study until the end of the 9th hour, then AUC will be calculated. | 9 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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VAC, negative pressure therapy, negative pressure, Wound therapy, NPWT, Vacuum therapy