Effects of hyperinflation on the oxygen pulse as a marker of cardiac performance in COPD.

A decreased inspiratory capacity (IC)/total lung capacity (TLC) ratio is associated with dynamic hyperinflation and decreased exercise capacity. The present authors hypothesised that static (low IC/TLC) and dynamic hyperinflation impair cardiac function as assessed by oxygen pulse at rest and during cardiopulmonary exercise testing (CPET). Lung function, body mass index, hand grip strength and CPET parameters were measured (oxygen uptake (mL x kg(-1) x min(-1)) and oxygen pulse (mL x beat(-1))) in 87 chronic obstructive pulmonary disease (COPD) patients (American Thoracic Society/European Respiratory Society/Global Initiative for Chronic Obstructive Lung Disease stage 3-4) and 46 controls. The patients were divided into those with IC/TLC > 25% or < or = 25%. The IC/TLC ratio at rest and at peak exercise was associated significantly with oxygen pulse. Patients with IC/TLC < or = 25% (n = 45) had significantly lower exercise capacity, peak oxygen pulse, peak minus baseline oxygen pulse, peak IC, peak IC/TLC ratio and % change from baseline to peak IC/TLC ratio compared with patients with IC/TLC > 25% and controls. During CPET, the oxygen pulse was lower at iso-work in patients with IC/TLC < or = 25% than in those with IC/TLC > 25%. Resting hyperinflation (inspiratory capacity/total lung capacity) is associated with lower oxygen pulse, peak exercise inspiratory capacity/total lung capacity and exercise capacity in patients with severe chronic obstructive pulmonary disease. The present results support an interaction between hyperinflation and decreased cardiac function that may contribute to exercise limitation in these patients.

The modified BODE index: validation with mortality in COPD.

Peak oxygen uptake (V'(O(2))) remains the gold standard measurement of exercise capacity and has been associated with survival. A modified BODE (body mass index, airflow obstruction, dyspnoea, exercise capacity) index replacing the 6-min walk distance (6MWD) with V'(O(2)) as % predicted (mBODE%) has been developed and found to have excellent correlation with the conventional BODE index. The objectives of the present study were to compare the ability of the conventional BODE and the mBODE% to predict mortality in 444 patients with chronic obstructive pulmonary disease (COPD) followed for a mean+/-SD period of 71+/-34 months. Anthropometrics, spirometry, lung volumes, comorbidity, cardiopulmonary cyclo-ergometry test and 6MWD were determined at entry. The mean BODE indices for the cohort were: BODE 4.1+/-2 and mBODE% 5.5+/-2. Both indices were significantly correlated with mortality. Logistic regression analysis with COPD survival as the dependent variable identified the BODE index, Charlson's and exercise capacity (in W) as variables associated with this outcome. In conclusion, the conventional BODE index, which uses the 6-min walk distance, predicts mortality in chronic obstructive pulmonary disease as well as the modified index using peak oxygen uptake. The results support the use of the simpler index, which includes the 6-min walk distance in the comprehensive evaluation of patients with chronic obstructive pulmonary disease.

C-reactive protein in patients with COPD, control smokers and non-smokers.

BACKGROUND: Patients with chronic obstructive pulmonary disease (COPD) have raised serum levels of C reactive protein (CRP). This may be related directly to COPD and its associated systemic inflammation or secondary to other factors such as concomitant ischaemic heart disease (IHD) or smoking status. The aim of this study was to evaluate IHD and smoking as potential causes of raised CRP levels in COPD and to test the association between inhaled corticosteroid (ICS) use and serum CRP levels. METHODS: Cross sectional analyses comparing cohorts of 88 patients with COPD, 33 smokers (S), and 38 non-smoker (NS) controls were performed. Clinical assessments included a complete medical history, pulmonary function, 6 minute walk test (6MWT), cardiopulmonary exercise test, and high sensitivity serum CRP measurements. RESULTS: Serum CRP levels were significantly higher in patients with COPD (5.03 (1.51) mg/l) than in controls (adjusted odds ratio 9.51; 95% confidence interval 2.97 to 30.45) but were similar in the two control groups (S: 2.02 (1.04) mg/l; NS: 2.24 (1.04) mg/l). There was no clinical or exercise evidence of unstable IHD in any of the subjects. CRP levels were lower in COPD patients treated with ICS than in those not treated (3.7 (3.0) mg/l v 6.3 (3.6) mg/l); this association was confirmed in an adjusted regression model (p<0.05). CONCLUSION: CRP levels are raised in COPD patients without clinically relevant IHD and independent of cigarette smoking, and reduced in patients with COPD using ICS. CRP may be a systemic marker of the inflammatory process that occurs in patients with COPD.

The 6-min walk distance: change over time and value as a predictor of survival in severe COPD.

The 6-min walk distance (6MWD) is used to evaluate the functional capacity of patients with chronic obstructive pulmonary disease (COPD). The change in 6MWD over time and its correlation with changes in spirometry and survival are unclear. Patients (n=198) with severe COPD and 41 age-matched controls were followed for 2 yrs, and anthropometrics, spirometry, 6MWD and comorbidities were measured. The 6MWD decreased in the COPD group from 238 +/- 107 m to 218 +/- 112 m (-26 +/- 37 m x yr(-1)), and increased in the control group from 532 +/- 82 m to 549 +/- 86 m (12 +/- 25 m x yr(-1)). In both groups, there was a poor correlation with changes in forced expiratory volume in one second (FEV1). Nonsurvivors in the COPD group (42%) had a more pronounced change in the 6MWD (-40 versus -22 m x yr(-1)) but a similar change in FEV1 (118 versus 102 mL x yr(-1)). The 6MWD independently predicted survival, after accounting for age, body mass index, FEV1 and comorbidities. In severe chronic obstructive pulmonary disease, the 6-min walk distance predicts mortality better than other traditional markers of disease severity. Its measurement is useful in the comprehensive evaluation of patients with severe disease.

Effect of blood pH on pulmonary artery pressure, left atrial pressure and fluid filtration rate in isolated rabbit lung.

To determine the effects of pH changes on Pulmonary Artery Pressure (PAP), 18 isolated rabbit lung preparations, perfused with autologous blood mixture and constant PaCO2 have been studied. Each preparation was studied under 3 conditions: Baseline: 30 minutes equilibration period. Acidosis: pH was decreased by 0.2 N HCl infusion, the ventilatory rate was changed and different CO2 mixtures were used to maintain the PCO2 within the initial parameters. Compensated Acidosis (CA): pH was returned to normal values by 0.7 N NaHCO3 infusion maintaining PCO2 in its initial values. The decrease in pH (acidosis) from 7.36 +/- 0.05 to 7.18 +/- 0.06 at constant PCO2, generated a significant increase in PAP (13.6 +/- 3.2 cm H2O to 18.8 +/- 5.2 cm H2O, p < 0.01). The pH increase (CA) from 7.18 +/- 0.06 to 7.40 +/- 0.09 caused the PAP to decrease (18.8 +/- 5.2 cm H2O to 15.9 +/- 4.2 cm H2O); the fluid filtration rate remained unchanged during the whole experiment. It is concluded that blood pH changes at constant PCO2 result in significant changes of PAP. Acidemia produces pulmonary vasoconstriction, which may be a contributing factor in the genesis of pulmonary hypertension in clinical conditions with increased hydrogen ion concentration [H+].

[Colonic tumors: experience at a clinical center in Caracas]. / Tumores de colon: experiencia en un centro clínico de Caracas.

During a period of six years, 33.452 histopathological studies were reviewed among which were found 285 cases with malignant neoplasm of the colon. 69% of the patients were between fifty and sixty years of age. The diagnosis of colonic adenocarcinoma was positive in 90.17% of the cases. 58.9% of the tumors were localized in the rectum and sigmoid. The remaining 41.06% of the tumors were not subject to rectosigmoidoscopy. The epidemiological analysis was made. Most of the patients were found with locally advanced cancer with a predominance of poor differentiated tumours, which represents a complex challenge to the surgeon.

[Effect of the administration of intralipid on liquid filtration rate and pressure of the pulmonary artery in isolated lung of rabbits]. / Efecto de la administración de Intralipid en la tasa de filtración de líquido y en la presión de la arteria pulmonar en el pulmón aislado de conejo.

INTRODUCTION: We study the effect on Intralipid on pulmonary circulation. METHODS: A 10% infusion of Intralipid was administered at a dose of 0.5/kg in 14 isolated rabbit lungs in which constant blood flow infusion was carried out principally in zone 3. The liquid filtration rate (LFR) and the mean pressure of the pulmonary artery were measured. RESULTS: A constant increase of mean pressure of the pulmonary artery was observed following the infusion (from 12.32 +/- 3.66 cm of H2O to 39.92 +/- 07.68 cmH2O (p < 0.01) which was associated to a significant increase in the rate of liquid filtration (from 0.018 +/- 0.01 g/min to 0.198 +/- 0.04 g/min; p < 0.01). CONCLUSIONS: The administration of Intralipid produces a statistically significant increase of mean pressure of the pulmonary artery and the rate of liquid filtration. This is probably caused by vasoconstriction due to metabolic changes produced by Intralipid on pulmonary circulation.

[Juvenile dermatomyositis. Clinical and epidemiologic experience]. / Dermatomiositis juvenil. Experiencia clínica y epidemiológica.

27 cases with a diagnosis of Juvenile Dermatomyositis were studied from a total of 1307 patients who suffered from connective tissue diseases; 19 of which met the diagnosis criteria of Bohan and Peters. Females were the most frequently affected. 52.63% of the cases presented the first symptoms between 5 and 9 years of age. Skin lesions, debility in inferior extremities and fever were the most frequent motives of consultation. The Aldolase and LDH were the muscular enzymes whose values increased in the majority of the cases. The electromyography was more sensible than the muscular biopsy in the diagnosis of the disease. We suggest that the epidemiologic and clinical characteristics found in our study should be taken into account for further accurate diagnosis of Juvenile Dermatomyositis in Venezuela.