ABSTRACT
Background: During the current COVID-19 pandemic, the use of protective masks is essential to reduce contagions. However, public opinion reports an associated subjective shortness of breath. We aimed to evaluate cardiorespiratory parameters, both at rest and during maximal exertion, to highlight any differences with the use of surgical masks and FFP2 masks compared to standard conditions in healthy subjects. Methods: Twelve subjects underwent three consecutive cardiopulmonary exercise tests (CPETs): without wearing protection mask, with surgical mask and with FFP2 mask (Figure 1). Subjects' degree of dyspnea was assessed by Borg Scale. Standard pulmonary function tests were performed at rest. Findings: All the subjects (40.8±12.4 years;6 male) completed the study protocol with no adverse event. At spirometry, from no mask to surgical to FFP2 a progressive reduction of FEV1 and FVC was observed (3.94±0.91L/s, 3.23±0.81L/s, 2.94±0.98L/ s and 4.70±1.21L, 3,77±1.02L, 3.52±1.21L, respectively, p<0.001) (Figure 2). Rest ventilation, O2 intake (VO2) and CO2 production (VCO2) were progressively lower due to a respiratory rate reduction. At peak exercise, subjects revealed a progressive higher Borg scale value when wearing surgical and FFP2 (Figure 3). At peak exercise VO2 (30.9±623.40, 27.50±6.92, 28.24±8.79ml/Kg/min, p=0.001), ventilation (92.29±25.99, 76.19±21.62, 71.63±21.19L, p=0.003), respiratory rate (41.52±8.02, 37.73±5.52, 37.11±4.53, p=0.04) and tidal volume (2.28±0.72, 2.05±0,60, 1.96±0.65L, p=0.001) were lower from no mask to surgical to FFP2. We did not observe a significant inter-group difference in oxygen sat-uration. Interpretation: Protective masks are associated with a significant but modest worsening spirometry and cardiorespiratory parameters at rest and peak exercise. The effect is driven by a ventilation reduction due to an increased air-flow resistance. However, since signs of exercise ventilatory limitation are far away to be reached, their use is safe even during maximal exercise, albeit with a slight reduction in performance.
ABSTRACT
Background and aim. In December 2019, in the city of Wuhan (China), a potential new causative agent of pneumonia, called the new coronavirus 2019 (nCoV-2019) was identified. Since then, the need to contain the global spread of the infection has become urgent through specific social distancing procedures and through the use of individual protection devices (i.e. airway protection masks). In the media doubts were raised about the impact of different types of masks on daily physical activity, in particular for those who perform physical exercise. In this context, we aimed to evaluate cardiorespiratory parameters, assessable through a cardiopulmonary exercise test (CPET), to highlight any differences with the use of surgical mask or filtering facepiece particles class 2 (FFP2) mask compared to the test performed under normal conditions. Methods. 12 healthy subjects, enrolled in July 2020, performed three consecutive CPETs at least 24 hours apart, but within 2 weeks, without wearing airway protection mask, with surgical mask and with FFP2 mask. The execution order of the CPETs was assigned in order to cover all possible combinations. During the CPETs, the consumption of Watts reached will be obscured to the subject. Before the start and immediately after the end of each CPET, maximum inspiratory pressure (MIP) and the maximum expiratory pressure (MEP) was also assessed. Results. Comparing the three conditions, we observed a progressive significant reduction in oxygen intake, carbon dioxide output, ventilation and respiratory rate at rest as well as at peak exercise (Table 1). The workload also decreased. We did not notice differences in blood oxygen saturation nor adverse events such as arrhythmias or ischemic events. MIP/MEP comparison did not reveal significant respiratory muscles fatigue. Discussion and Conclusions. The use of airway protection masks during pandemics (e.g. nCoV-2019) is a key safeguard to contain viral transmission. In healthy subjects it reduces, both at rest and during exercise, ventilation values (mainly due to reduction of respiratory rate) without detectable alteration of arterial saturation, heart rate, respiratory muscle fatigue and/or adverse events even during a maximum effort. Our speculative hypothesis is that the effect is likely to be related to the presence of a mechanical obstacle to ventilation. Our data show that the use of masks is still compatible with the execution of physical activity even if the maximum workload is slightly reduced. In conclusion airway protection masks (both surgical mask and FFP2) can be safely used in daily life despite a slight impact on ventilation and metabolic parameters.