Clinical trial NCT04980820: Changes in Capillary Carbon Dioxide Partial Pressure (pCO2) While Wearing FFP2 / FFP3 Masks
Official title: Changes in Capillary pCO2 While Wearing FFP2 and FFP3 Masks Masks by Medical Staff - a Prospective Cross-over Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Hypercapnia
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2021-07-28
Enrollment: 200
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: 1. arm: starts with no mask - FFP2 mask - FFP3 mask
2. arm: starts with no mask - FFP3 mask - FFP2 mask
Primary purpose: DIAGNOSTIC

Brief summary: 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: 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.

Eligibility criteria: 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

Primary outcomes:
measure: Change of PcCO2
timeFrame: 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 outcomes:
measure: Change of PcO2
timeFrame: 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)
measure: Respiratory rate
timeFrame: 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)
measure: Exertion score
timeFrame: 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)
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Medical University of Vienna
Study officials:
affiliation: Medical University of Vienna, Dept. of Anaesthesiology, Critical Care and Pain Medicine
name: Georg Röder, M.D.
role: PRINCIPAL_INVESTIGATOR
References:
citation: Paules CI, Marston HD, Fauci AS. Coronavirus Infections-More Than Just the Common Cold. JAMA. 2020 Feb 25;323(8):707-708. doi: 10.1001/jama.2020.0757. No abstract available.
citation: Fletcher SJ, Clark M, Stanley PJ. Carbon dioxide re-breathing with close fitting face respirator masks. Anaesthesia. 2006 Sep;61(9):910. doi: 10.1111/j.1365-2044.2006.04767.x. No abstract available.
citation: Ozdemir L, Azizoglu M, Yapici D. Respirators used by healthcare workers due to the COVID-19 outbreak increase end-tidal carbon dioxide and fractional inspired carbon dioxide pressure. J Clin Anesth. 2020 Nov;66:109901. doi: 10.1016/j.jclinane.2020.109901. Epub 2020 May 22.
citation: Kim JH, Benson SM, Roberge RJ. Pulmonary and heart rate responses to wearing N95 filtering facepiece respirators. Am J Infect Control. 2013 Jan;41(1):24-7. doi: 10.1016/j.ajic.2012.02.037. Epub 2012 Sep 1.