Blood gas levels, cardiovascular strain and cognitive performance during surgical mask and filtering face piece application

Abstract

Mask induced airway resistance and carbon dioxide rebreathing is discussed to impact gas exchange and to induce discomfort and impairments in cognitive performance. N = 23 healthy humans (13 females, 10 males; 23.5 ± 2.1 years) participated in this randomized crossover trial (3 arms, 48-h washout periods). During interventions participants wore either a surgical face mask (SM), a filtering face piece (FFP2) or no mask (NM). Interventions included a 20-min siting period and 20 min steady state cycling on an ergometer at 77% of the maximal heart rate (HR). Hemodynamic data (HR, blood pressure), metabolic outcomes (pulse derived oxygen saturation, capillary carbon dioxide (pCO2), and oxygen partial pressure (pO2), lactate, pH, base excess), subjective response (ability to concentrate, arousal, perceived exertion) and cognitive performance (Stroop Test) were assessed. Compared to NM, both masks increased pCO2 (NM 31.9 ± 3.3 mmHg, SM = 35.2 ± 4.0 mmHg, FFP2 = 34.5 ± 3.8 mmHg, F = 12.670, p < 0.001) and decreased pH (NM = 7.42 ± 0.03, SM = 7.39 ± 0.03, FFP2 = 7.39 ± 0.04, F = 11.4, p < 0.001) during exercise. The FFP2 increased blood pressure during exercise (NM = 158 ± 15 mmHg, SM = 159 ± 16 mmHg, FFP2 = 162 ± 17 mmHg, F = 3.21, p = 0.050), the SM increased HR during sitting (NM = 70 ± 8 bpm, SM = 74 ± 8 bpm, FFP2 = 73 ± 8 bpm, F = 4.70, p = 0.014). No mask showed any comparative effect on other hemodynamic, metabolic, subjective, or cognitive outcomes. Mask wearing leads to slightly increased cardiovascular stress and elevated carbon dioxide levels during exercise but did not affect cognitive performance or wellbeing.

Effects of wearing different face masks on cardiopulmonary performance at rest and exercise in a partially double-blinded randomized cross-over study

“…Sample size calculation (G*Power Ver. 3.9.1, level of alpha = 0.05, power = 0.80) based on different cardiopulmonary parameters (e.g., minute ventilation (VE), heart rate (HR), blood oxygen saturation (sO 2 ), transcutaneous CO 2 (tCO 2 )) were performed using the data of previous studies 8 , 10 , 12 , 15 . The largest number of subjects to be assumed was 39 (exercise with a surgical mask (SM) and without wearing a mask).…”

“…The housing of a common bacterial filter was used as an adapter for the mask material to prevent influencing the ventilation measurement by the CPET silicone mask, which has been suspected as an influencing factor in studies where face masks were worn underneath the CPET mask 10 , 13 . In addition, the examinations could be carried out in a double-blind setting for the first time.…”

“…Numerous studies showed that wearing masks during physical exercise causes non-health relevant decreases in blood oxygen as well as slight increases in blood carbon dioxide 2 , 4 – 10 . However, the majority of these studies focused on relevant clinical parameters, sporting leisure activities and investigated short-term loads of up to 300 watts and more on a bicycle ergometer which does not represent typical conditions in everyday life or at workplaces 11 – 15 .…”

“…However, the majority of these studies focused on relevant clinical parameters, sporting leisure activities and investigated short-term loads of up to 300 watts and more on a bicycle ergometer which does not represent typical conditions in everyday life or at workplaces 11 – 15 . Some authors also reported physiological effects after continuous or moderate loads 10 , 15 – 19 . In most studies, during cardiopulmonary exercise test (CPET), the face mask was worn underneath the silicone mask required for CPET, which has been discussed as influencing factor 4 – 7 , 13 .…”

“…In most studies, during cardiopulmonary exercise test (CPET), the face mask was worn underneath the silicone mask required for CPET, which has been discussed as influencing factor 4 – 7 , 13 . Additionally, measurements were predominantly performed on young, well-trained people 10 , 14 , 20 – 22 and none of the preceding studies was blinded with respect to the type of mask to be worn by the subjects or focused on breathing physiology or breathing mechanics.…”