Effects of wearing a FFP2 mask on indirect calorimetry measurements: A pilot study

Abstract

Background & aims: During the coronavirus disease 2019 (COVID-19) pandemic the use of Indirect calorimetry (IC) during nutritional rehabilitation program requires special precautions due to possible contagions for patients and health professionals. We evaluated in a sample of healthy subjects the agreement between oxygen consumption (VO₂ mL/min), carbon dioxide production (VCO₂ mL/min), respiratory quotient (RQ) and resting energy expenditure (REE kcal/24 h/day) measured by IC with and without a filtering facepiece mask.

Materials: 10 subjects with a mean (SD) age of 43 (10) years and a body mass index of 25.2 (5.8) kg/m² underwent indirect calorimetry both with and without a class 2 filtering facepiece mask (FFP2), in random order. The limits of agreement (LOA) and the concordance correlation coefficient (CCC) were used to evaluate the interchangeability of the measurement conditions.

Results: The LOA between REE measured with and without FFP2 (-111 to 189 kcal/day) were comparable to those for repeated IC tests without wearing masks and CCC (0.95) showed substantial agreement.

Conclusions: We observed high agreement between REE measured by IC with and without FFP2 mask. These procedures are interchangeable in clinical practice.

Keywords: Coronavirus disease 2019; Covid-19; FFP2; Facepiece filtering mask; Indirect calorimetry.