Desaturation during Physical Exercise in COPD Patients - a Stable-over-time Phenomenon.

INTRODUCTION: Exercise-induced desaturation is a common finding in patients with moderate and severe COPD. It is an important marker in the course of disease that has a prognostic value for mortality risk. AIM: To monitor over time COPD patients with and without desaturation during 6-minute walking test (6MWT) and to assess the stability of that phenomenon. MATERIALS AND METHODS: A 6MWT was administered to 70 patients with COPD which ranged in severity from stage 2A to stage 4D (GOLD 2011); the patients had a mean age of 64.5±10.1, mean pack-years - 38.8±21, FEV1% = 46.4%±15.7%, FVC% = 73.7%±1.3%, MRC = 2.31±0.84, CAT = 20.8±6.6. Oxygen saturation was monitored during the test; indications for desaturation were a decrease of SpO2 by ≥4% and a fall in SpO2 to ≤88% for at least 3 min. The patients were followed-up for mean 40.9±22.3 months and tests were repeated. RESULTS: Patients were divided into two groups based on the decrease in SpO2: Group A included patients with desaturation (n=35) and Group B - patients with no desaturation (n=35). In 66 of the patients the desaturation profile was stable over time. Only two patients, who did not desaturated at baseline, experienced desaturation in the follow-up 6MWT and another two patients, who desaturated at baseline, did not have it later in the follow-up. CONCLUSION: Desaturation is a phenomenon that is persistent over time. Based on the results, it could be concluded that exercise-induced desaturation is a major marker of a particular COPD phenotype.

Multidimensional system for assessment of COPD patients. Comparison with BODE index.

AIM: To present the principles of a multidimensional system for assessment of COPD patients, called DOREMI BOX, and to compare it with BODE index. The letters of the abbreviation stand for the following: D--dyspnea, O--obstruction, RE--rate of exacerbation, MI--movement (exercise) intolerance, B--Body Mass Index, OX--blood oxygen disturbances. METHODS: For validation of DOREMI BOX we tested 84 patients with COPD (age = 59 +/- 9 years, FEV1% = 35 +/- 14%; Charlson index = 2.7 +/- 1.0) in clinically stable condition. The prognostic value of the new system was validated prospectively in a cohort of 68 COPD patients followed-up for a minimum of 36 months. RESULTS: The mean value of DOREMI BOX score was 6.0 +/- 1.8 (range = 3-10), and for BODE index--4.7 +/- 2.2 (range = 1-10). Construct validity has been demonstrated between DOREMI BOX score and symptoms score (R=0.52; P<0.001). DOREMI BOX score correlates strongly with the classic indices for assessment and staging of COPD--FEV1%, dyspneic scales, blood gases, 6MWD, which proves its concurrent validity. After 36 months there were 22 deaths and 46 survivals. Patients with higher DOREMI BOX score were at a higher risk of death. The hazard ratio for death from any cause per one-point increase in the DOREMI BOX score was 1.44 (95% CI, 1.06-1.95; P=0.009). CONCLUSIONS: DOREMI BOX has construct and concurrent validity for assessment of COPD and slightly better ability than BODE index to predict risk for death in COPD patients.

Maximal inspiratory pressure predicts mortality in patients with chronic obstructive pulmonary disease in a five-year follow-up.

INTRODUCTION: The therapeutic modality for the treatment of COPD depends on the proper determination of all factors that may have an effect on the course and prognosis of the disease. AIM: To assess the prognostic role of maximal inspiratory pressure (PImax) and a large group of lung function parameters in patients with COPD followed up over a period of five years. PATIENTS AND METHODS: A cohort of 63 COPD patients (age 58.6 +/- 8.8 yrs, BMI 24.2 +/- 5.6, FEV1% = 35 +/- 14%, PImax = 52.3 +/- 19.0 cm H2O; x +/- S x) was recruited for a 5-year prospective study. Mortality was assessed as overall mortality. The independent predictors of survival were determined using the Cox proportional hazards model. RESULTS: The deceased patients (n = 32) had lower values of BMI, FEV1, DL(CO)/V(A)%, PaO2, PImax, and six-minute walking test (6MWT) and higher RV/TLC% (p < 0.05) than the survivors. The regression model included the following parameters: age, BMI, smoking history, FEV1, FVC, DL(CO)/V(A)%, lung hyperinflation (RV/TLC%), PImax, PaO2, PaCO2, hematocrit, mean pulmonary artery pressure (mPAP - Doppler echocardiography), symptoms (Anthonisen scale), dyspnea, comorbidity (Charlson index), frequency of exacerbations in the previous year, and the exercise capacity (6MWT). Statistical analysis indicated that PImax was an independent predictor of mortality (p = 0.005). CONCLUSION: Low PImax was associated with greater overall mortality rate in this cohort of patients with COPD.

Correlation of frequency of exacerbations with the BODE index in COPD patients.

BACKGROUND: In recent research B. Celli et al. (N Engl J Med 2004;350:1005-12) proposed a complex grading system (which they designated by BODE) for predicting the mortality risk in chronic obstructive pulmonary disease (COPD). OBJECTIVE: The aim of the study was to compare the BODE index in COPD patients with frequent exacerbations and in those with infrequent exacerbations. PATIENTS AND METHODS: A 1-year retrospective study was performed in 76 patients with COPD of mean (Sx) age of 59.1 (8.6) years, forced expiratory volume in 1 second % predicted (FEV1%) = 35 (13)%. Exacerbations were ascertained retrospectively by patient interview and from records of treatment such as healthcare databases; the effect of frequent or infrequent exacerbations (> or < 2.3 per year) on the BODE index was examined. RESULTS: A total of 178 exacerbations were recorded. Exacerbation frequency was correlated significantly to BODE index (r = 0.36; P = 0.002). There was a statistically significant difference in the BODE index score (5.6 +/- 2.5 vs 4.1 +/- 1.5; P = 0.002) between the frequent and infrequent exacerbators. CONCLUSION: COPD patients who experienced frequent exacerbations in a previous year have significantly higher BODE score than those who experience infrequent exacerbations.

Long-term changes in dyspnea, lung function, and exercise capacity in COPD patients.

OBJECTIVE: To examine longitudinal changes in dyspnea, lung function, and exercise capacity in COPD patients and to compare baseline data of frequent and infrequent exacerbators at trial entry. METHODS: Nineteen stable COPD patients without significant co-morbidity (age, 58.4 +/- 8.4 years; FEV1% = 33 +/- 12%; mean +/- SD) participated in the study. After a mean period of 36 months (range = 24 - 49) the patients were retested using an identical protocol. RESULTS: Repeated measures analysis showed that there was significant deterioration of FEV1 L (from 1.028 +/- 0.349 to 0.928 +/- 0.307; p = 0.007), PImax cm H2O (from 61.9 +/- 24.2 to 42.0 +/- 22.1; p = 0.007), PaO2 mm Hg (from 69.0 +/- 8.6 to 60.1 +/- 6.8; p = 0.003), PaCO2 mm Hg (from 43.1 +/- 4.9 to 47.3 +/- 4.5; p = 0.001), ATS (from 2.4 +/- 1.0 to 2.8 +/- 0.8; p = 0.031), and 6MWD m (from 389 +/- 130 to 341 +/- 135; p = 0.014). There were also changes in IC, T(L,CO)/V(A), PAP and Borg, but they were not statistically significant. Differentiation of patients by frequency of exacerbations per year of observation (> 2 < or =) discriminated them with respect to functional parameters (FEV1, FVC, IC), dyspneic indices (ATS, VAS and Borg) and exercise capacity (6MWD) at the time of enrollment. CONCLUSIONS: 1) Lung function parameters, blood-gas and dyspneic indices, and exercise capacity decline over a mean period of 36 month in patients with COPD; 2) Patients with frequent exacerbations experience more dyspnea and have lower levels of lung function and exercise capacity at trial entry.

Tidal breathing analysis in school-age children. Comparison with the parameters of forced expiration.

UNLABELLED: Tidal breathing analysis is a method which has the potential to be used for distinguishing and follow-up of airflow obstruction (AFO) in infants, children and critically ill patients. The aim of the present study was to analyse the tidal breathing parameters (TBP) in healthy and in asthmatic school-age children and to compare them with the parameters of forced expiration. SUBJECTS: Two hundred and twenty five healthy children and 100 asthmatics (7 to 14 years- old) took part in the present study. RESULTS: The results show that TBPs exhibit great inter- and intraindividual variability, even if the mean value of 10 consecutive breathing cycles is used. Parameters that reflect the tidal expiratory flow pattern--V(PTEF)/V(E) and T(PTEF)/T(E) demonstrate high variability and no correlation with age, sex and anthropometric parameters in healthy children. These indices are useful for detection of acute changes in bronchomotor tonus in asthmatics - V(PTEF)/V(E) = 36.1 +/- 6.6% vs. 32.6 +/- 6.2% (methacholine) vs. 37.4 +/- 7.5% (salbutamol) and T(PTEF)/T(E) = 34.2 +/- 6.2% vs. 28.6 +/- 7.8% vs. 35.3 +/- 7.5%, resp. (P < 0.05 everywhere; n = 34) as well as for discriminating a group of subjects with AFO vs. controls (V(PTEF)/V(E) = 30.9 +/- 6.5% vs. 35.3 +/- 8.0%; P = 0.005, and T(PTEF)/T(E) = 29.0 +/- 6.7% vs. 32.8 +/- 7.6%; P = 0.016). The evaluation of the area under the ROC curves (AUC) in the asthmatic group showed weak discriminative capacity of T(PTEF)/T(E) and V(PTEF)/V(E) in comparison to FEV1 (AUC of T(PTEF)/T(E) = 0.62; 95%CI 0.51-0.74). CONCLUSIONS: Tidal breathing parameters could add insight t.o the functional profile but are not capable of substituting forced expiration regarding detection of overt airflow obstruction in school-age children.

Cardiovascular and dyspnea response to six-minute and shuttle walk tests in COPD patients.

UNLABELLED: Previous studies focusing on the changes of heart rate, systolic blood pressure and dyspnea caused by the six-minute (6MWT) and shuttle walking distance tests (ISWT) have produced conflicting data. The present study aims at comparing the cardiovascular and dyspnea responses to 6MWT and ISWT in patients with chronic obstructive pulmonary disease (COPD). Twenty patients with clinically stable COPD (age, 56 +/- 9 yrs; BMI, 27.8 +/- 7.7 kg.m(-2); FEV1%pred, 42 +/- 19%; mean +/- Sx) performed three 6MWTs and two ISWTs using standardised protocols. The distances walked in the third 6MWT and second ISWT were 458 +/- 105 and 365 +/- 116 m, respectively. There was a significant correlation between the distances covered in the two tests (r = 0.87; p < 0.001). The 6MWT and ISWT showed similar correlation coefficients with the Baseline Dyspnea Index (r = 0.86; p < 0.001 and r = 0.76; p < 0.001), the Clinical Symptom Scale (r= -0.72; p < 0.001 and r= -0.55; p = 0.011), FEV1 L (r = 0.36; NS and r = 0.30; NS), PImax (r = 0.59; p < 0.008 and r = 0.60; p = 0.001) and the mean pulmonary artery pressure, Doppler echocardiography (r= -0.51; p < 0.029 and r = -0.51; p = 0.032). Although the response to ISWT tended to be greater, we found no statistically significant differences between the two tests in the changes of heart rate (HR), systolic blood pressure (SBP) and dyspnea (Borg) (deltaHR, 17.9 +/- 13.4 vs 23.8 +/- 15.4; deltaSBP, 7.7 +/- 14.6 vs 13.0 +/- 17.0 and deltaBorg, 1.7 +/- 1.1 vs 2.2 +/- 0.9; NS). CONCLUSION: The cardiovascular and dyspnea response caused by ISWT is greater (but statistically not significant) than that generated by 6MWT. The more limited the functional capacity of COPD patients the more similar the response generated by 6MWT and ISWT.