BackgroundComputed tomography (CT) phenotypic characterization helps in understanding the clinical diversity of chronic obstructive pulmonary disease (COPD) patients, but its clinical relevance and its relationship with functional features are not clarified. Volumetric capnography (VC) uses the principle of gas washout and analyzes the pattern of CO2 elimination as a function of expired volume. The main variables analyzed were end-tidal concentration of carbon dioxide (ETCO2), Slope of phase 2 (Slp2), and Slope of phase 3 (Slp3) of capnogram, the curve which represents the total amount of CO2 eliminated by the lungs during each breath.ObjectiveTo investigate, in a group of patients with severe COPD, if the phenotypic analysis by CT could identify different subsets of patients, and if there was an association of CT findings and functional variables.Subjects and methodsSixty-five patients with COPD Gold III–IV were admitted for clinical evaluation, high-resolution CT, and functional evaluation (spirometry, 6-minute walk test [6MWT], and VC). The presence and profusion of tomography findings were evaluated, and later, the patients were identified as having emphysema (EMP) or airway disease (AWD) phenotype. EMP and AWD groups were compared; tomography findings scores were evaluated versus spirometric, 6MWT, and VC variables.ResultsBronchiectasis was found in 33.8% and peribronchial thickening in 69.2% of the 65 patients. Structural findings of airways had no significant correlation with spirometric variables. Air trapping and EMP were strongly correlated with VC variables, but in opposite directions. There was some overlap between the EMP and AWD groups, but EMP patients had signicantly lower body mass index, worse obstruction, and shorter walked distance on 6MWT. Concerning VC, EMP patients had signicantly lower ETCO2, Slp2 and Slp3. Increases in Slp3 characterize heterogeneous involvement of the distal air spaces, as in AWD.ConclusionVisual assessment and phenotyping of CT in COPD patients is feasible and may help identify functional and clinically different subsets of patients. VC may provide useful information about the heterogeneous involvement of lung structures in COPD.

Mortality from severe TBI is high in Latin American LMIC, although the rate of favorable recovery is similar to that of high-income countries. Demographic factors such as race and study site played an outsized role in predicting outcome; further research is required to understand these associations.

This study was designed to use volumetric capnography to evaluate the breathing pattern and ventilation inhomogeneities in patients with chronic sputum production and bronchiectasis and to correlate the phase 3 slope of the capnographic curve to spirometric measurements. Twenty-four patients with cystic fibrosis (CF) and 21 patients with noncystic fibrosis idiopathic bronchiectasis (BC) were serially enrolled. The diagnosis of cystic fibrosis was based on the finding of at least two abnormal sweat chloride concentrations (iontophoresis sweat test). The diagnosis of bronchiectasis was made when the patient had a complaint of chronic sputum production and compatible findings at high-resolution computed tomography (HRCT) scan of the thorax. Spirometric tests and volumetric capnography were performed. The 114 subjects of the control group for capnographic variables were nonsmoker volunteers, who had no respiratory symptoms whatsoever and no past or present history of lung disease. Compared with controls, patients in CF group had lower SpO(2) (P < 0.0001), higher respiratory rates (RR) (P < 0.0001), smaller expiratory volumes normalized for weight (V(E)/kg) (P < 0.028), smaller expiratory times (Te) (P < 0.0001), and greater phase 3 Slopes normalized for tidal volume (P3Slp/V(E)) (P < 0.0001). Compared with controls, patients in the BC group had lower SpO(2) (P < 0.0001), higher RR (P < 0.004), smaller V(E)/kg (P < 0.04), smaller Te (P < 0.007), greater P3Slp/V(E) (P < 0.0001), and smaller VCO(2) (P < 0.0002). The pooled data from the two patient groups compared with controls showed that the patients had lower SpO(2) (P < 0.0001), higher RR (P < 0.0001), smaller V(E)/kg (P < 0.05), smaller Te (P < 0.0001), greater P3Slp/V(E) (P < 0.0001), and smaller VCO(2) (P < 0.0003). All of the capnographic and spirometric variables evaluated showed no significant differences between CF and BC patients. Spirometric data in this study reveals that the patients had obstructive defects with concomitant low vital capacities and both groups had very similar abnormalities. The capnographic variables in the patient group suggest a restrictive respiratory pattern (greater respiratory rates, smaller expiratory times and expiratory volumes, normal peak expiratory flows). Both groups of patients showed increased phase III slopes compared with controls, which probably indicates the presence of diffuse disease of small airways in both conditions leading to inhomogeneities of ventilation.

Pulmonary arterial hypertension (PAH) impairs exercise tolerance and daily physical activity (PA). Aside from the hemodynamic limitations, physical, cognitive and emotional factors may play a relevant and as yet unexplored role. We investigated whether there is an association between the PA level and psychological disorders, health-related quality of life, and daily activities. We also searched for an association of the PA level with clinical factors and functional capacity. This was an analytical, cross-sectional, observational study conducted in a Brazilian University Hospital. Twenty stable PAH subjects wore an accelerometer for a week and completed an activity diary. They answered the quality of life questionnaire (SF-36), as well as the anxiety and depression scale (HADS), and the Manchester Respiratory Activities of Daily Living questionnaire (MRADL). Transthoracic echocardiography, the 6-Minute walk test (6MWT), the 1-minute sit-to-stand test (STST), and spirometry were performed. For statistical analysis we used Chi-square tests or Fisher's test as appropriate and the Mann-Whitney test to compare numerical values between two groups. The relationship between the parameters was assessed using the Spearman correlation test. The mean age was 44.3 years, 80% were women, 80% had idiopathic PAH, and 20% had connective tissue disease . The mean daily step count was 4,280 ± 2,351, and the mean activity time was 41.6 ± 19.3 minutes. The distance covered (6MWT) was 451.5 m, and the number of movements (1-STST) was 23.8. Thirty percent scored positive for anxiety, and 15% for depression (HADS). There was a significant correlation between accelerometer data and walking distance (6MWT), number of movements (1-STST), level of daily physical activity (MRADL), and depression symptoms. Our findings support the hypothesis that other aspects beyond physical and hemodynamic ones might impact the daily physical activity of patients with PAH.

Objective: To compare spirometry and volumetric capnography (VCap) to determine if the capnographic values add more information about early lung disease in cystic fibrosis (CF) patients.Methods: This was a cross-sectional study involving CF patients: Group I (42 patients, 6-12 years of age); and Group II (22 patients, 13-20 years of age). The corresponding control groups were comprised of 30 and 50 healthy subjects, respectively. Forced vital capacity (FVC), forced expiratory volume in one second (FEV 1 ), and the FEV 1 /FVC ratio was determined by spirometry. Using VCap, we measured peripheral oxygen saturation (SpO 2 ), respiratory rate (RR), inspiratory time (IT), expiratory time (ET), and the phase III slope normalized by expiratory volume (phase III slope/Ve). Results:In comparison with control groups, all CF patients presented higher phase III slope/Ve values (p < 0.001) independent of the pulmonary disease stage. The phase III slope/Ve was significantly higher in the 24 patients who presented normal spirometry results (p = 0.018). The Group II patients showed lower FVC, FEV 1 , FEV 1 /FVC (p < 0.05), and also lower SpO 2 values (p < 0.001) when compared with Group I patients. In comparison with Control Group II, the Group II patients presented higher RR (p < 0.001), and lower IT and ET values (p < 0.001). Conclusions:Compared to the controls, all studied CF patients showed an increase in phase III slope/Ve values. VCap identified the heterogeneity of the ventilation distribution in the peripheral airways of CF patients who presented normal spirometry.J Pediatr (Rio J). 2012;88(6)

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OBJECTIVE: To determine the probability of oxygen desaturation in healthy individuals undergoing the incremental shuttle walk test (ISWT). METHODS: We enrolled 83 healthy subjects: 55 males (including 1 smoker) and 28 females. We determined pre-ISWT FEV1, FEV6, HR and SpO2, as well as post-ISWT HR and SpO2. RESULTS: Mean values overall were as follows: age, 35.05 ± 12.53 years; body mass index, 24.30 ± 3.47 kg/m2; resting HR, 75.12 ± 12.48 bpm; resting SpO2, 97.96 ± 1.02%; FEV1, 3.75 ± 0.81 L; FEV6, 4.45 ± 0.87 L; FEV1/FEV6 ratio, 0.83 ± 0.08 (no restriction or obstruction); incremental shuttle walk distance, 958.30 ± 146.32 m; post-ISWT HR, 162.41 ± 18.24 bpm; and post-ISWT SpO2, 96.27 ± 2.21%. In 11 subjects, post-ISWT SpO2 was higher than was pre-ISWT SpO2. In 17 subjects, there was a 4% decrease in SpO2 after the ISWT. There were no statistically significant differences between the groups with and without post-ISWT oxygen desaturation in terms of age, gender, FEV1, FEV6, FEV1/FEV6, pre-ISWT SpO2, incremental shuttle walk distance, HR, or percentage of maximal HR. In the individuals with post-ISWT oxygen desaturation, the body mass index was higher (p = 0.01) and post-ISWT SpO2 was lower (p = 0.0001). CONCLUSIONS: Healthy individuals can present oxygen desaturation after the ISWT. Using the ISWT to predict subtle respiratory abnormalities can be misleading. In healthy subjects, oxygen desaturation is common after the ISWT, as it is during any intense physical activity.

The use of a new model of ETT may decrease the risks of tracheal injury without hindering respiratory mechanics.