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

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

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.

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.

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)

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)

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)

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)

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

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.

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.

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.

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.

https://www.who.int/publications/i/item/rational-use-of-personal-protective-equipment-for-coronavirus-disease-(covid-19)-and-considerations-during-severe-shortages

Rational use of personal protective equipment for coronavirus disease (COVID-19) and considerations during severe shortages