Physiological predictors of cardiorespiratory fitness in children and adolescents with cystic fibrosis without ventilatory limitation

Objectives: [1] To investigate the cardiorespiratory fitness (CRF) levels in children and adolescents with cystic fibrosis (CF) with no ventilatory limitation (ventilatory reserve ⩾ 15%) during exercise, and [2] to assess which physiological factors are related to CRF. Methods: A cross-sectional study design was used in 8- to 18-year-old children and adolescents with CF. Cardiopulmonary exercise testing was used to determine peak oxygen uptake normalized to body weight as a measure of CRF. Patients were defined as having ‘low CRF’ when CRF was less than 82%predicted. Physiological predictors used in this study were body mass index z-score, P. Aeruginosa lung infection, impaired glucose tolerance (IGT) including CF-related diabetes, CF-related liver disease, sweat chloride concentration, and self-reported physical activity. Backward likelihood ratio (LR) logistic regression analysis was used. Results: Sixty children and adolescents (51.7% boys) with a median age of 15.3 years (25th–75th percentile: 12.9–17.0 years) and a mean percentage predicted forced expiratory volume in 1 second of 88.5% (±16.9) participated. Mean percentage predicted CRF (ppVO2peak/kg) was 81.4% (±12.4, range: 51%–105%). Thirty-three patients (55.0%) were classified as having ‘low CRF’. The final model that best predicted low CRF included IGT ( p = 0.085; Exp(B) = 6.770) and P. Aeruginosa lung infection (p = 0.095; Exp(B) = 3.945). This model was able to explain between 26.7% and 35.6% of variance. Conclusions: CRF is reduced in over half of children and adolescents with CF with normal ventilatory reserve. Glucose intolerance and P. Aeruginosa lung infection seem to be associated to low CRF in children and adolescents with CF.

Importance of Cardiopulmonary Exercise Testing Amongst Subjects Recovering from COVID-19

The cardiopulmonary exercise test (CPET) provides an objective assessment of ventilatory limitation, related to the exercise minute ventilation (VE) coupled to carbon dioxide output (VCO2) (VE/VCO2); high values of VE/VCO2 slope define an exercise ventilatory inefficiency (EVin). In subjects recovered from hospitalised COVID-19, we explored the methodology of CPET in order to evaluate the presence of cardiopulmonary alterations. Our prospective study (RESPICOVID) has been proposed to evaluate pulmonary damage’s clinical impact in post-COVID subjects. In a subgroup of subjects (RESPICOVID2) without baseline confounders, we performed the CPET. According to the VE/VCO2 slope, subjects were divided into having EVin and exercise ventilatory efficiency (EVef). Data concerning general variables, hospitalisation, lung function, and gas-analysis were also collected. The RESPICOVID2 enrolled 28 subjects, of whom 8 (29%) had EVin. As compared to subjects with EVef, subjects with EVin showed a reduction in heart rate (HR) recovery. VE/VCO2 slope was inversely correlated with HR recovery; this correlation was confirmed in a subgroup of older, non-smoking male subjects, regardless of the presence of arterial hypertension. More than one-fourth of subjects recovered from hospitalised COVID-19 have EVin. The relationship between EVin and HR recovery may represent a novel hallmark of post-COVID cardiopulmonary alterations.

“You can leave your mask on”: effects on cardiopulmonary parameters of different airway protection masks at rest and during maximal exercise

BackgroundDuring the COVID-19 pandemic, the use of protection masks is essential to reduce contagions. However, public opinion reports an associated subjective shortness of breath. We evaluated cardiorespiratory parameters at rest and during maximal exertion to highlight any differences with the use of protection masks.MethodsTwelve healthy subjects underwent three cardiopulmonary exercise tests: without wearing protection mask, with surgical and with FFP2 mask. Dyspnea was assessed by Borg Scale. Standard pulmonary function tests were also performed.ResultsAll the subjects (40.8±12.4 years; 6 males) completed the 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±0.91 l, 3.23±0.81 l, 2.94±0.98 l and 4.70±1.21 l, 3.77±1.02 l, 3.52±1.21 l, respectively, p<0.001). Rest ventilation, O2 uptake (V̇O2) and CO2 production (VCO2) were progressively lower with a reduction of respiratory rate. At peak exercise, subjects revealed a progressively higher Borg scale when wearing surgical and FFP2. Accordingly, at peak exercise, V̇O2 (31.0±23.4, 27.5±6.9, 28.2±8.8 ml/kg/min, p=0.001), ventilation (92±26, 76±22, 72±21 l, p=0.003), respiratory rate (42±8, 38±5, 37±4, p=0.04) and tidal volume (2.28±0.72, 2.05±0.60, 1.96±0.65 l, p=0.001) were gradually lower. We did not observed a significant difference in oxygen saturation.ConclusionsProtection masks are associated with significant but modest worsening of spirometry and cardiorespiratory parameters at rest and peak exercise. The effect is driven by a ventilation reduction due to an increased airflow resistance. However, since exercise ventilatory limitation is far from being reached, their use is safe even during maximal exercise, with a slight reduction in performance.

Central airway compression by massively dilated pulmonary artery in a patient with pulmonary arterial hypertension: a rare entity

Patients with pulmonary arterial hypertension (PAH) usually die from progressive right ventricular failure. Mechanical complications due to pulmonary artery (PA) enlargement are rare and include tracheobronchial and left main coronary artery compression, and PA dissection. A 62-year-old female with PAH was seen in our office for follow-up. During the evaluation, spirometry was performed, which revealed a severe obstructive ventilatory limitation. Subsequent workup identified compression of bilateral mainstem bronchi from the dilated PA as the aetiology for the abnormal spirometry. Very few cases of this rare complication have been reported in the literature. A significant dilation of the PA is necessary (>4 cm) for the occurrence of these complications. Dilation of PA is an independent risk factor for sudden unexpected death in patients with PAH.