Biomedical subjects

B Nicotra

Publications and source records attributed to B Nicotra.

7 recordsLinked to original sources

PubMed1994

Differing effects of airway obstruction on physical work capacity and ventilation in men and women with COPD.

BACKGROUND: Although the natural history of COPD is thought to be well known, studies assessing differences in the onset and course of the disease by gender are surprisingly lacking. This study is a cross-sectional analysis using progressive cycle ergometry exercise testing to assess male and female patients at specific levels of airway obstruction to see if they differ in their exercise capacity and decline in functional capacity. METHODS: The study group included 417 patients with COPD, 55 to 85 years of age, who were compared with 29 controls of similar age; all patients had COPD (FEV1/FVC < 75% predicted) without restrictive disease. Exercise testing in groups based on the level of pulmonary dysfunction defined by FEV1/FVC ratios (mild, 60.5 to 69.5%; moderate, 50.5 to 60.5%; severe < 50.5%) was analyzed. Data were evaluated using the Statistical Analysis System, analyzing gender and degree of airway obstruction and adjusting for any difference in age and peak exercise heart rate (covariate analysis of variance). RESULTS: Men demonstrated progressive reductions of body weight, exercise ability (assessed by the VO2), oxygen pulse (O2P, an indicator of stroke volume), and maximum exercise ventilation (VEmax) even with mild pulmonary dysfunction. Women did not lose weight, and maintained usual exercise ability (VO2, VEmax) and O2P until moderate or severe disease was present. Additional confirmation of a decrease in cardiac function for men with mild airway obstruction (p < 0.0001, controls), but not for women with mild airway disease, was obtained by estimation of cardiac output. Further, women presented with COPD at lower levels of tobacco smoke exposure than men for the entire group (43.8 vs 63.0 pack-years, p < 0.0001) and for each subgroup of disease severity. There were proportionally more life-time female nonsmokers than male nonsmokers with COPD (16 vs 5, p < 0.001). CONCLUSIONS: Male and female patients with COPD differed in their decline of functional aerobic capacity even at equivalent levels of pulmonary dysfunction. One reason for this appeared to be a decrease in the O2P occurring early in the natural history of the disease in the men and not in the women. Although general body de-conditioning may be the cause, heart disease may also be a contributing aspect. The relative delay in the loss of exercise capacity and body mass by the women may relate to predisease differences in physical activity. Women manifested significant lung disease with less cigarette smoking than men. This may be attributable to a different susceptibility to cigarette smoke between the sexes. These results suggest that there appear to be differences in the natural history of COPD in men and women.

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PubMed1993

Altered exercise gas exchange and cardiac function in patients with mild chronic obstructive pulmonary disease.

Patients with advanced COPD have significantly reduced gas exchange and pulmonary function; however, little is known regarding physical work capacity and exercise gas exchange in patients with mild COPD. A total of 39 individuals (20 men and 19 women) without evidence of COPD (controls) and 51 individuals (29 men and 22 women) with mild COPD (FEV1 > or = 60 percent of predicted; and ratio of FEV1 over forced vital capacity of 60 to 70 percent) were tested to determine resting pulmonary function and resting and peak exercise gas exchange in response to progressive maximal cycle ergometer testing. In general, those with mild COPD had similar smoking histories and essentially equivalent resting gas exchange studies as compared to the controls. Measured maximal oxygen consumption was less in both the male (p < 0.003) and the female patients (p < 0.001). This was due, in part, to a lower maximal ventilation in the men with obstruction (p < 0.04), resulting from a significant reduction in tidal volume (p < 0.05). Women presented with similar decreases in maximal ventilation (p < 0.04) and maximal tidal volume (p < 0.01), while no difference in maximal respiratory rate was noted in either group (p > 0.05). Breathing reserve was 32 percent and 53 percent less for the male and female patients with obstruction than for controls. Maximal heart rates were less in the individuals with obstruction, where they reached 93 percent (p < 0.02) and 96 percent (p < 0.003) of the age- and sex-specific maximal heart rates for men and women as compared to 101 percent and 99 percent obtained in the controls. Achieved absolute work loads for men and women (in kilogram.meters per minute) were lower in the groups with obstruction (p < 0.002 and 0.0003) as well. These results demonstrate that work capacity and gas exchange are significantly decreased in individuals with even mild COPD. The reduction in functional work capacity is secondary to a loss of pulmonary function, as well as chronic deconditioning. Increased dyspnea may be responsible for the premature cessation of exercise observed in patients with mild COPD. Thus, early intervention with exercise training may be warranted to counter the deleterious effects of deconditioning and declining pulmonary function in patients with mild COPD.

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PubMed1988

Exercise conditioning in the rehabilitation of patients with chronic obstructive pulmonary disease.

Fifty-nine patients with severe chronic obstructive pulmonary disease (COPD) performed pulmonary function and exercise tests before and after participation in a 12-day pulmonary rehabilitation inpatient program. Postdischarge follow-ups were performed at three months. Training consisted of twice daily aerobic exercise of 30 to 40 minutes' duration. Intensity of training was determined after exercise testing and approached the maximal limits of ventilation. In general, the program failed to demonstrate significant changes in pulmonary function. Exceptions were mid-expiratory flow rate (FEF25-75) (p less than .02) and peak flow rate (p less than .05). Evaluation of exercise capacity via maximal exercise testing yielded significant increases in caloric expenditure (p less than .001), peak exercise oxygen consumption (p less than .001), and work output (p less than .0001). Peak exercise ventilation increased significantly (p less than .005) due to an increase in tidal volume (p less than .002). Work efficiency improved with training, but the change was not statistically significant. Resting oxygen consumption and carbon dioxide production were decreased (p less than .05); tidal volume was increased (p less than .005). However, the significant increase noted in tidal volume did not alter minute ventilation. In general, the changes noted at 12 days were maintained at three months postdischarge. These data support the hypothesis that a short-term, in-hospital program of general exercise conditioning can improve work output, gas exchange, and mechanical efficiency without significantly affecting spirometric indices. These changes may translate into improved performance of activities of daily living and a sense of general well-being.

Efficiency↗

PubMed1987

Demand oxygen delivery during exercise.

Nine hypoxemic patients with COLD, whose hypoxemia is aggravated by minimal exercise, volunteered for this study. Each subject underwent two treadmill exercise trials at two oxygen delivery settings, each on the DODS and SF delivery systems for a total of four exercise trials. We measured SaO2 via ear oximetry and recorded oxygen usage per minute. We compared the oxygen usage required for the two techniques to achieve an SaO2 of 90 percent. The results indicate that the mean oxygen requirement using the DODS to achieve an SaO2 of 90 percent was 211.4 ml/min as compared to SF delivery which required 1,610.9 ml/min. This implies an oxygen savings advantage of the DODS over SF of 7:1. The fact that the DODS oxygen savings extends to exercise conditions lends support to its use in portable oxygen therapy. Widespread use of this and other oxygen savings techniques could result in significant cost savings while maintaining the desired benefits of supplemental oxygen administration.

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PubMed1986

Branhamella catarrhalis as a lower respiratory tract pathogen in patients with chronic lung disease.

To determine the possible role of Branhamella (formerly Neisseria) catarrhalis as a respiratory pathogen, we screened quality sputa (defined by cellular criteria) that showed numerous gram-negative cocci on Gram's stain for the presence of B catarrhalis. In an eight-month period, 52 isolates of B catarrhalis were identified in adults attending a hospital for chest diseases. During this period B catarrhalis was the third most common potential pathogen isolated from sputa. Twenty-two patients (42%) had associated patchy bronchopneumonic or lobar infiltrates. All had negative blood cultures and a generally mild clinical course. The majority of strains (73%) of B catarrhalis produced beta-lactamase and were resistant to penicillin and ampicillin. Isolates (including beta-lactamase-producing strains) were susceptible to erythromycin, tetracycline, and trimethoprim-sulfamethoxazole. These studies demonstrate that in patients with chronic lung disease, the presence of B catarrhalis in sputum can be suspected on the basis of a Gram's stain and may be associated with the development of new pneumonic infiltrates. Since these organisms frequently produce beta-lactamase, empiric antimicrobial therapy should include agents other than the penicillins.

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PubMed1984

Evaluation of a low-flow oxygen-conserving nasal cannula.

Oxygen therapy is one of the most frequently ordered therapies for patients with chronic obstructive pulmonary disease (COPD). In a large percentage of these cases, oxygen therapy is supplied via nasal cannula. With the rising cost of medical care and the search for more effective means of oxygen delivery, a new oxygen-conserving nasal cannula (CNC) that incorporates a closely coupled 20-ml reservoir was developed. Oxygen is stored in the reservoir during exhalation so that 20 ml of approximately 85% oxygen is the first gas inhaled. To test the hypothesis that the CNC is more efficient than the standard nasal cannula (SNC), 20 patients with COPD were evaluated. All patients were chronically hypoxemic at rest. Results indicate that when the CNC was compared with the SNC, arterial oxygen saturation levels were significantly different (p less than 0.001) at flow rates of 0.5, 1.0, and 2.0 L/min. Oxygen saturation were 2.9% higher at 0.5 L/min, 2.9% higher at 1 L/min, and 2.6% higher at 2 L/min for the CNC than for the SNC. In summary, the CNC offers a more efficient oxygen delivery system for those patients requiring supplemental oxygen administration by nasal cannula.

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PubMedDate not supplied

Rod myopathy with extensive systemic and respiratory muscular involvement.

A patient with both muscle weakness and progressively degenerating respiratory function became increasingly less responsive to therapeutic intervention. The diagnosis of the muscle disease was made through biopsy samples and confirmed as rod myopathy. Through autopsy samples, the patient was found to have had extensive centriacinar emphysema and widespread involvement of rod disease in the skeletal muscles. The most involved of the muscles sampled (anterior tibial, brachioradialis, rectus femoris, psoas, diaphragm, biceps) was the diaphragm. While the influence on diaphragmatic function has been reported in the juvenile form of rod disease, this is the first known report of the extensiveness of involvement in adult-onset disease. The diseased state of the diaphragm was appreciated as a contributing factor to the respiratory insufficiency.

Adult↗