Anamelia C. Faria

Sleep Apnea Clinical Score, Berlin Questionnaire, or Epworth Sleepiness Scale: which is the best obstructive sleep apnea predictor in patients with COPD?

Introduction The Sleep Apnea Clinical Score (SACS) and the Berlin Questionnaire (BQ) are used to predict the likelihood of obstructive sleep apnea (OSA). The Epworth Sleepiness Scale (ESS) is used to assess daytime sleepiness, a common OSA symptom. These clinical tools help prioritize individuals with the most severe illness regarding on whom polysomnography (PSG) should be performed. It is necessary to check the applicability of these tools in patients with chronic obstructive pulmonary disease (COPD). The aim of this study is to compare SACS, BQ, and ESS performance in patients with COPD. Methods The SACS, BQ, and ESS were applied to 91 patients with COPD. From this group, 24 underwent PSG. In this transversal study, these three tests were compared regarding their likelihood to predict OSA in patients with COPD using receiver-operating characteristic curve statistics. Results In this sample, 58 (63.7%) patients were men, and their mean age was 69.4±9.6 years. Fourteen patients (15.4%) had a high probability of OSA by SACS, 32 (32.5%) had a high probability by BQ, and 37 (40.7%) had excessive diurnal somnolence according to the ESS. From the 24 patients who underwent PSG, OSA diagnosis was confirmed in five (20.8%), according to the American Academy of Sleep Medicine criteria. BQ and ESS did not accurately predict OSA in this group of patients with COPD, with a receiver-operating characteristic curve area under the curves of 0.54 (95% CI: 0.329–0.745, P=0.75) and 0.69 (95% CI: 0.47–0.860, P=0.10), respectively. SACS performance was significantly better, with an area under the curve of 0.82 (95% CI: 0.606–0.943, P=0.02). Conclusion SACS was better than BQ and ESS in predicting OSA in this group of patients with COPD.

Validation of the Forced Oscillation Technique in the diagnostic of respiratory changes in patients with silicosis

Silicosis is a typical occupational respiratory disease characterized by irreversible alterations throughout the alveolar and interstitial structure. The objectives of this study were (1) investigate the potential of the Forced Oscillation Technique (FOT) in the analysis of the patients with silicosis, and (2) evaluate the ability of FOT to identify early alterations in the respiratory mechanics of these patients. Sixty-one volunteers were analyzed: 20 healthy subjects and 41 with silicosis; these, were divided into 4 groups according to spirometric results: normal spirometric exam (n = 11); mild obstruction (n = 20); moderate and severe obstruction (n = 10.). A significant (p<0.0001) increase in total resistance (R0) and mean resistance (Rm) were observed, as well as a decrease in the dynamic compliance (p<0.0003) and mean reactance (p<0.000004). R0 and Rm obtained adequate accuracy for clinical use (>80%). FOT parameters adequately described the pathophysiological changes associated with silicosis and presented adequate accuracy for clinical use, indicating that this technique can be helpful in the evaluation respiratory mechanics in this disease.

Diagnostic performance of the Forced Oscillation Technique in the detection of early respiratory changes in Rheumatoid Arthritis

The objective of this study was to evaluate the clinical potential of the Forced Oscillation Technique (FOT) in the detection of the early alterations in respiratory mechanics of Rheumatoid Arthritis (RA) patients. A total of 36 individuals were analyzed, 18 healthy and 18 with RA. The clinical usefulness of the parameters was evaluated investigating sensibility (Se), specificity (Sp) and the area under the receiver operating characteristic curve (AUC). In the RA group, all the 3 studied parameters obtained high accuracy for clinical use (AUC>0.9), while in spirometric parameters, no parameter obtained appropriate accuracy for clinical use (AUC<0.7). In conclusion, the parameters obtained by FOT presented adequate Se and Sp, indicating that this technique can be helpful in the evaluation of the early respiratory mechanical alterations in patients with RA.

Efeito do uso de Broncodilatadores nas Propriedades Resistivas e Reativas do Sistema Respiratório de Indivíduos Saudáveis e com Doença Pulmonar Obstrutiva Crônica

In Chronic Obstructive Pulmonary Disease (COPD) the response to inhaled bronchodilators by means of spirometry is controversial. The objective of this study was to determine the effect acute of salbutamol on the resistive and reactive properties of the respiratory system in COPD patients. A total of 38 subjects were analyzed, 10 healthy control e 28 with COPD, We used the forced oscillation technique (FOT) before and after inhalation of 300 ug salbutamol. Impedance data were interpreted using the total respiratory system resistance (R0); the dynamic compliance (Cdyn); and the slope of the resistance (S), both of which are associated with the homogeneity of the respiratory system. All groups show significant differences between the prebronchodilator and postbronchodilator, except of the healthy subjects in FOT parameters. Values of p < 0.001 were obtained for R0 and S in comparisons between all groups. In all groups Δ%R0, Δ%S e Δ%Cdin was inversely related with the classification of the disease. We conclude that the use of salbutamol improved the resistive properties of the respiratory system of COPD patients proportionally to the degree of airway obstruction. The FOT provide parameters that could be helpful in the analysis of bronchodilation in COPD.

Efeito do Tempo de Doença na Biomecânica Respiratória de Pacientes Portadores de Artrite Reumatóide

Rheumatoid arthritis (RA) is a rheumatic disease that primarily affects peripheral joints, but its mortality is directly related to pulmonary involvement. Some results have shown that spirometric exams are often normal in these individuals. Recently, a prototype of an instrument implementing the Forced Oscillation Technique (FOT) was used in the analysis of these patients, showing significant adverse modifications in biomechanics. This study evaluates the effect of the duration of the disease on respiratory function by spirometry and FOT. For this purpose, the study involved 11 normal subjects and 38 patients that were classified into four groups according to disease duration. There was no change in the values of spirometric parameters with disease duration. On the other hand, the FOT resistive parameters R0 and Rm increased significantly (p<0.0001, p<0.00001), while the dynamic compliance (Cdyn,rs) decreased significantly (p<0.00001), with disease duration. The correlations confirm these results, demonstrating r2 values of 0.11 for R0 and 0.24 for Cdyn,rs. We conclude that there are significant changes in the biomechanical properties of the respiratory system of individuals with RA that are associated with disease duration and that this early changes may be detected by the FOT.