ABSTRACT
Since the beginning of the SARS-CoV-2 pandemic, the community use of facemasks has been widely recommended. However, their use during exercise has raised safety concerns. Thus, we compared the physiological differences between exercising wearing a surgical (SM) or a double-layer-cotton (DLC) facemask and not wearing a mask (NM). Sixteen volunteers underwent 4 bouts of cycling-based exercise, which consisted of two different intensities: light-to-moderate and moderate-to-high. Facemasks were used as follows: bout-1 and 4: NM; bout-2: SM or DLC and bout-3: DLC or SM. Ventilatory, metabolic, pulmonary gas exchange (PGE) and perceptual variables were collected. At both exercise intensities compared to NM, both facemasks induced similar ventilatory adaptations, increasing inspiratory time and tidal volume and decreasing breathing frequency. Effect sizes (ES) were larger for DLC than for SM. At moderate-to-high, both facemasks reduced the minute ventilation, whereas at light-to-moderate, it was only seen with DLC. End tidal and mixed CO2 pressures, as well as the difference between them, increased with both facemasks. Again, ES was larger for DLC than SM. No relevant oxygen saturation drop was observed with both facemaks and exercise intensities. A small ES increament in VO2 and VCO2 were seen with both facemasks. Effort perception increased at moderate-to-high for both exercise intensities, buth larger EF were with DLC than SM . DLC increased facial temperature during both exercise intensities. In conclusion, ventilatory adjustments imposed during facemask exercise influenced PGE and metabolic and perceptual changes. Larger ES were mostly seen for DLC than SM.Abbreviations: Bf: Breathing frequency.; CPET: Cardiopulmonary exercise test.; CI: Confidence interval.; DLC: Double-layer cotton.; ETCO2: End tidal CO2 pressure.; ES: Effect size.; ΔET-PECO2: Difference between ETCO2 and PECO2.; FMMT: Facemask microclimate temperature.; HR: Heart rate.; IQR: Interquartile range.; NM: No mask.; PECO2: Mixed-expired CO2 pressure.; RER: Respiratory exchange ratio.; RPE: Rate of perceived effort.; SD: Standard deviation.; SM: Surgical Mask.; SpO2: Oxygen saturation.; STP: Subjective thermal perception.; Ti/TTOT: Duty cycle.; VE: Minute ventilation.; VCO2: Carbon dioxide output.; VO2: Oxygen uptake.; VT: Tidal volume.; VT: Ventilatory threshold. HighlightsFacemasks affect the breathing pattern by changing the frequency and amplitude of pulmonary ventilation.The augmented ventilatory work increases VO2, VCO2, and RPE and promotes nonconcerning drops in SpO2 and CO2 retention.Increased inspiratory and expiratory pressure can account for the reduction in pulmonary physiological dead space.
ABSTRACT
HIGHLIGHTS: Weeks after the acute disease phase, one-third of mild and three-quarters of severe and critical patients with COVID-19 presented a reduced aerobic capacity. Previous studies including SARS-CoV-1 survivors observed much lower values.A severe or critical COVID-19 case was an independent predictor for low aerobic capacity.In our sample, pre-COVID-19 exercise significantly reduced the odds of post-COVID-19 low aerobic capacity. Even severe or critical patients who exercised regularly had a prevalence of low aerobic capacity 2.5 times lower than those who did not have this routine before sickening.
ABSTRACT
BACKGROUND: COVID-19 causes severe pulmonary involvement, but the cardiovascular system can also be affected by myocarditis, heart failure and shock. The increase in cardiac biomarkers has been associated with a worse prognosis. OBJECTIVES: To evaluate the prognostic value of Troponin-T (TNT) and natriuretic peptide (BNP) in patients hospitalized for Covid-19. METHODS: This was a convenience sample of patients hospitalized for COVID-19. Data were collected from medical records to assess the association of TnT and BNP measured in the first 24 hours of hospital admission with the combined outcome (CO) of death or need for mechanical ventilation. Univariate analysis was used to compare the groups with and without the CO. Cox's multivariate model was used to determine independent predictors of the CO. RESULTS: We evaluated 183 patients (age = 66.8±17 years, 65.6% of which were males). The time of follow-up was 7 days (range 1 to 39 days). The CO occurred in 24% of the patients. The median troponin-T and BNP levels were 0.011 and 0.041ng/dL (p <0.001); 64 and 198 pg/dL (p <0.001), respectively, for the groups without and with the CO. In the univariate analysis, in addition to TnT and BNP, age, presence of coronary disease, oxygen saturation, lymphocytes, D-dimer, t-CRP and creatinine, were different between groups with and without outcomes. In the bootstrap multivariate analysis, only TnT (1.12 [95% CI 1.03-1.47]) and t-CRP (1.04 [95% CI 1.00-1.10]) were independent predictors of the CO. CONCLUSION: In the first 24h of admission, TnT, but not BNP, was an independent marker of mortality or need for invasive mechanical ventilation. This finding further reinforces the clinical importance of cardiac involvement in COVID-19. (Arq Bras Cardiol. 2020; 115(4):660-666).
FUNDAMENTO: A COVID-19 causa grave acometimento pulmonar, porém o sistema cardiovascular também pode ser afetado por miocardite, insuficiência cardíaca e choque. A elevação de biomarcadores cardíacos tem sido associada a um pior prognóstico. OBJETIVOS: Avaliar o valor prognóstico da Troponina T (TnT) e do peptídeo natriurético tipo B (BNP) em pacientes internados por Covid-19. MÉTODOS: Amostra de conveniência de pacientes hospitalizados por COVID-19. Foram coletados dados dos prontuários com o objetivo de avaliar a relação da TnT e o BNP medidos nas primeiras 24h de admissão com o desfecho combinado (DC) óbito ou necessidade de ventilação mecânica. Análise univariada comparou os grupos com e sem DC. Modelo multivariado de Cox foi utilizada para determinar preditores independentes do DC. RESULTADOS: Avaliamos 183 pacientes (idade=66,8±17 anos, sendo 65,6% do sexo masculino). Tempo de acompanhamento foi de 7 dias (1 a 39 dias). O DC ocorreu em 24% dos pacientes. As medianas de TnT e BNP foram 0,011 e 0,041 ng/dl (p<0,001); 64 e 198 pg/dl (p<0,001) respectivamente para os grupos sem e com DC. Na análise univariada, além de TnT e BNP, idade, presença de doença coronariana, saturação de oxigênio, linfócitos, dímero-D, proteína C reativa titulada (PCR-t) e creatinina, foram diferentes entre os grupos com e sem desfechos. Na análise multivariada boostraped apenas TnT (1,12[IC95%1,03-1,47]) e PCR-t (1,04[IC95%1,00-1,10]) foram preditores independentes do DC. CONCLUSÃO: Nas primeiras 24h de admissão, TnT, mas não o BNP, foi marcador independente de mortalidade ou necessidade de ventilação mecânica invasiva. Este dado reforça ainda mais a importância clínica do acometimento cardíaco da COVID-19. (AArq Bras Cardiol. 2020; 115(4):660-666).