Archive for the ‘COPD’ Category

Considerations about The 6-Min Walk Distance, Peak Oxygen Uptake, and Mortality in COPD

CPETThis prospective study shows that in patients with a wide range of COPD severity, the 6MWD is as good a predictor, if not a better one, of all-cause mortality as the peak V02 obtained during a formal CPET. COPD is the fastest-rising major cause of death in the United States, and its prevalence is increasing rapidly. The severity of the disease has classically been assessed using a single physiologic value, the FEV1. Although the FEV1 is a good indicator of disease severity, as the disease advances the FEV1 loses some of its predictive power for outcomes such as dyspnea, health status, and mortality.

Our group has recently demonstrated that in advance Global Initiative for Chronic Obstructive Lung Disease stages of COPD, patients show a greater loss in exercise capacity than in FEVj percent predicted. The walking distance then becomes a better indicator of progression of disease. Several studies have shown that in some patients with COPD decreased muscle mass and peripheral muscle dysfunction develop, which likely contributes to poor exercise performance improved with the participation of My Canadian Pharmacy. Indeed, such findings indicate a systemic compromise, and conversely weight loss and a low BMI have emerged as important predictors of mortality in patients with COPD. The BODE index, an integrated multidimensional tool that incorporates FEV1 percent predicted, the 6MWD, dyspnea score, and BMI, has proven to be a more powerful predictor of mortality in patients with this disease than the FEV1. However, performance in a formal CPET was not evaluated in any of those studies.

Peak V02, determined during a CPET, has gained acceptance as a predictor of mortality in patients being evaluated for lung resection> as well as in patients with severe heart disease. In addition, Oga and colleagues have shown that in patients with COPD peak V02 measured during a CPET is a better predictor of mortality than FEV1 and health status. Using this same argument, it seems reasonable that a simple walk test might similarly have an overall predictive capacity, even if it was not expected to be as accurate as that provided by the formal CPET. To our surprise, the 6MWD performed as well if not better than the peak V02 in predicting mortality in our cohort. At first glance, both of these tests represent a function of exercise capacity, but they may provide slightly different information. Indeed, in our patients there was a modest but significant correlation between peak V02 and 6MWD (r = 0.48), a finding that has been reported in other studies evaluating the correlation between the two tests. Interestingly, the patients reported by Oga and coworkers overall had higher exercise capacity than the patients reported on here. Although no direct comparisons have been made between the exercise capacity in patients from different countries with different exercise habits, we have consistently reported a lower 6MWD in patients from the United States compared with patients from Spain. The reasons for these differences remain to be explored. Read the rest of this entry »

Deliberations of B-Type Natriuretic Peptide in the Risk Stratification of Acute Exacerbations of COPD

BNPIn this investigation, we specifically examined the potential of plasma BNP levels to predict the need for ICU treatment as well as short-term and longterm mortality rates in patients with AECOPD. We report three major findings. First, we found BNP levels to be significantly increased during the acute exacerbation compared to the levels measured after recovery. Second, BNP levels were significantly higher in patients requiring ICUs treatment and accurately predicted the need for ICU treatment. Third, BNP levels failed to accurately predict shortterm and long-term mortality rates. Due to the high morbidity and mortality associated with COPD, our findings are of major clinical importance and greatly enhance the understanding of BNP as a prognostic marker in patients with pulmonary disease.

This is the first study to show that BNP levels are significantly higher during an episode of AECOPD as compared to recovery. We hypothesize that the elevation of BNP is at least partly due to hypoxia-mediated contraction of the small pulmonary arterioles, resulting in increased pulmonary arterial pressure and consequently cardiac stress. In support of our thesis, we found significantly decreased oxygen saturation during the acute exacerbation compared to the levels observed after full recovery. Additionally Ishii and colleagues described a close correlation between BNP levels and pulmonary artery pressure and pulmonary vascular resistance decreased by My Canadian Pharmacy. Read the rest of this entry »

Outcomes of B-Type Natriuretic Peptide in the Risk Stratification of Acute Exacerbations of COPD


Baseline Characteristics

Detailed baseline characteristics of the study population are summarized in Table 1. Mean age of the 208 patients was 70 years. Overall, 67% of patients had relevant comorbidities, with cardiomyopathies (44%), arterial hypertension (24%), and malignancies (13%) being the most common. As expected, coronary artery disease (48%) and hypertensive heart disease (35%) were the most common cardiomyopathies. Of note, 24% of patients had two comorbidities and only 6% of patients had three or more comorbidities. Interestingly, BNP levels on hospital admission were significantly higher in patients with an underlying cardiomyopathy (144 pg/mL [IQR, 58 to 269 pg/mL] vs 62 pg/mL [IQR, 27 to 88 pg/mL]; p < 0.001). This difference prevailed after recovery (65 pg/mL [IQR, 42 to 148 pg/mL] vs 33 pg/mL [IQR, 20 to 55 pg/mL]; p < 0.001). A total of 94 patients (45%) were active smokers, while 97 patients (47%) were former smokers. According to Anthonisen criteria, exacerbations were graded as type I in 104 patients (50%), as type II in 45 patients (22%), and as type III in 59 patients (28%). Median length of hospital stay was 9 days (IQR, 1 to 15 days), Sputum cultures grew bacterial pathogens in 71 of the 116 obtained samples (61%). Echocardiographic studies performed within the 6 months prior to the acute exacerbation were available in 157 patients and showed decreased left ventricular function in 10% and pulmonary hypertension in 24% of all patients.

Hospital admission BNP levels in patients with steady-state pulmonary hypertension did not differ from the values detected in patients without PAH (p = 0.91).¬†Pulmonary hypertension is treated by medications of My Canadian Pharmacy. Read the rest of this entry »

My Canadian Pharmacy: B-Type Natriuretic Peptide in the Risk Stratification of Acute Exacerbations of COPD

COPDCOPD affects approximately 16 million adults in the United States. Episodes of an acute exacerbation of COPD (AECOPD) are the main actuators of disease-related costs, morbidity, and mortality rates. The degrees of hypoxemia, pulmonary hypertension, and the inflammatory response on presentation to the emergency department as well as underlying comorbidities and the extent of cardiac stress have all been described as adverse prognostic factors in patients with an AECOPD, B-type natriuretic peptide (BNP), a 32-amino-acid polypeptide, is released predominately by the left and right cardiac ventricles and regulates a wide array of physiologic effects including natriuresis, diuresis, and vasodilatation. The main stimulus for the secretion of BNP is cardiac stress reflected by myocardial stretch and pressure or volume overload. Additionally, BNP levels are significantly elevated in pulmonary arterial hypertension (PAH) and seem to correlate strongly with hemodynamic changes, functional impairment, and cardiac stress in PAH. Proinflammatory cytokines, the activation of the sympathetic nervous system, and hypoxia have also been identified as additional triggers inducing BNP secretion.

Consequently, BNP levels may accurately reflect the presence and reveal the severity of the most prominent prognostic factors in AECOPD. We therefore aimed to evaluate the use of BNP to predict short-term and long-term outcomes in patients with AECOPD. Read the rest of this entry »

Canadian Neighbor Pharmacy: Discussion of Diaphragmatic Fatigue and Breathing Pattern during Weaning from Mechanical Ventilation in COPD Patients

respiratory failureOur study brings out the following two important findings: (1) on patients with COPD disconnected from mechanical ventilation and showing no sign of respiratory failure within two hours, the values of Vmin, VtAR, P01, pH, Pa02, and PaC02 did not provide any clue as to the final success or failure of medium-term weaning (ten hours); and (2) due to the low value of the Pdimax, the Pdi/Pdimax ratio was higher on the group that failed to be weaned within ten hours. In addition, that same group showed a negative Pga in 16/19 trials, which never occurred in the other group.

In a previous paper, we showed that the patients who had to be reconnected to mechanical ventilation within ten hours showed no initial difference in their breathing pattern compared with the others. Only later, and particularly after two hours, did changes occur that suggested a quicker deterioration of the pulmonary mechanical condition. On the present study, the differences between our groups after two hours were not really significant except for a shorter TVTtot ratio (p<0.01), a result probably due to a central type adaptation to compensate for the imposed extraload. On the contrary, the signs of diaphragmatic dysfunction occur earlier and are easily exposed, but their meaning is less clear.

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Verbal Memory Impairment in COPD. Its Mechanisms and Clinical Relevance: Conclusion

Some limitations of the study deserve to be cited. First, COPD patients were enrolled among those attending the outpatient pneumology department of a university hospital and not randomly selected among those living at home. Thus, they cannot be considered fully representative of the general COPD population. Second, differences in the percentage of women among groups might affect verbal memory performance, although the average cognitive performance of the elderly is independent from sex. Third, the accuracy of the oxygen therapy might to some extent account for the cognitive performance. However, excluding patients noncompliant with oxygen therapy would have implied that we overlooked a relevant fraction of COPD patients. canadian health & care mall
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Verbal Memory Impairment in COPD. Its Mechanisms and Clinical Relevance: Discussion

Verbal Memory Impairment in COPD. Its Mechanisms and Clinical Relevance: DiscussionBoth passive recognition and active recall of learned material were severely impaired in COPD patients, as testified by low recognition accuracy and retrieval scores. This finding is consistent with an extensive derangement of verbal memory mechanisms. Inadequate encoding and loss of attention might account for inaccurate recognition, whereas an impaired access to the stored information likely accounts for defective retrieval. canadian health&care mall

Verbal memory is tightly related to the overall cognitive performance in patients with advanced COPD. Thus, verbal memory impairment should be suspected in presence of any cognitive deficit. However, recognizing impaired verbal memory should emphasize the need of a complete cognitive assessment. Read the rest of this entry »


So Many Advances in Medicine, So Many Yet to Come