Changes in Capillary Carbon Dioxide Partial Pressure (pCO2) While Wearing FFP2 / FFP3 Masks

Study Overview
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Brief Summary
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The aim of this study is to determine whether there are any changes in the carbon dioxide partial pressure in medical staff while wearing a filtering face piece (FFP) 2 or FFP3 mask. Furthermore, changes in the capillary oxygen partial pressure, the subjective respiratory effort and the breathing rate are measured.

Detailed Description
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In the fight against the severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2), the personal protective equipment (PPE) of medical staff plays a special role. Since the pathogen can be transmitted via droplets, particle-filtering half masks (filtering face piece - FFP) are a substantial part of the PPE. The current data indicate that there may be an increase in the carbon dioxide partial pressure (PcCO2) in the blood when wearing an FFP2 / 3 mask during routine medical activity. The aim of this prospective cross-over study is to compare the PcCO2 measured by capillary blood sampling from medical staff while wearing an FFP2 or FFP3 mask. The PcCO2 determined without a mask serves as a reference value. While no mask is worn, the PcCO2, the subjective respiratory effort, the breathing rate and the capillary oxygen partial pressure (PcO2) is measured. The study participants then wear an FFP2 or FFP3 mask for one hour, and the same parameters are collected. Subsequently, the participant switches to an FFP3 or FFP2 mask, and the last measurement is conducted after one hour.

Official Title
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Changes in Capillary pCO2 While Wearing FFP2 and FFP3 Masks Masks by Medical Staff - a Prospective Cross-over Study

Conditions
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Hypercapnia

Intervention / Treatment
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* Other: No mask
* Device: Filtering face mask 2 (FFP2)
* Device: Filtering face mask 3 (FFP3)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: medical staff working at the Vienna General Hospital oral and written consent to take part voluntarily in this trial Exclusion Criteria: hypersensitivity / allergy against Nonylvanillamid, Nikotinsäure-beta-butoxyethylester or other component of Finalgon Salbe not Coronavirus disease-19 vaccinated pregnancy breastfeeding

Ages Eligible for Study
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Minimum Age: 18 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: Diagnostic
Allocation: Non-Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: arm: starts with no mask - FFP2 mask - FFP3 mask arm: starts with no mask - FFP3 mask - FFP2 mask
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: FFP2<br>This arm starts with a FFP2 mask and switches to a FFP3 mask. | Other: No mask<br>* The participant is asked to wear no mask for 10 minutes.<br>Device: Filtering face mask 2 (FFP2)<br>* The participant is asked to wear a FFP2 mask for 1 hour during work.<br>Device: Filtering face mask 3 (FFP3)<br>* The participant is asked to wear a FFP3 mask for 1 hour during work.<br>|
| Experimental: FFP3<br>This arm starts with a FFP3 mask and switches to a FFP2 mask. | Other: No mask<br>* The participant is asked to wear no mask for 10 minutes.<br>Device: Filtering face mask 2 (FFP2)<br>* The participant is asked to wear a FFP2 mask for 1 hour during work.<br>Device: Filtering face mask 3 (FFP3)<br>* The participant is asked to wear a FFP3 mask for 1 hour during work.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of PcCO2 | Change of capillary carbon dioxide partial pressure (PcCO2) | 1. measurement after 10 minutes without mask, 2. measurement after 1 hour with mask (FFP2/3), 3. measurement after 1 hour with mask (FFP3/2) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change of PcO2 | Change of capillary oxygen partial pressure (PcO2) | 1. measurement after 10 minutes without mask, 2. measurement after 1 hour with mask (FFP2/3), 3. measurement after 1 hour with mask (FFP3/2) | 
| Respiratory rate | Number of breaths per minute | 1. measurement after 10 minutes without mask, 2. measurement after 1 hour with mask (FFP2/3), 3. measurement after 1 hour with mask (FFP3/2) | 
| Exertion score | Participant subjective score: How difficult is it for you to breathe at the moment?; scale from 1-5, 1= easy, 2= rather easy, 3= moderate, 4= rather hard, 5= hard | 1. measurement after 10 minutes without mask, 2. measurement after 1 hour with mask (FFP2/3), 3. measurement after 1 hour with mask (FFP3/2) |