Pneumatic compression stocking (PCS) devices have been introduced to decrease the incidence of postoperative deep venous thrombosis (DVT). However, their role in the prophylaxis against pulmonary embolism (PE) remains unclear. This study was undertaken to compare the prophylactic effectiveness of subcutaneous heparin (SCH) alone vs the combined use of PCS and SCH in the prevention of PE following cardiac surgery.

The production of cytotoxic oxygen radicals by activated granulocytes is a proposed mechanism of lung injury in ARDS. Protective effects of N-acetylcysteine (NAC) have been described in experimental and clinical ARDS. NAC could act in part by replenishing the intracellular stores of glutathione (GSH) in activated granulocytes, leading to detoxification of oxygen radicals produced by these cells. To test this hypothesis, 16 patients in the early phase of ARDS were randomized to receive either NAC (n = 8) or placebo (n = 8); granulocyte GSH, granulocyte oxygen radical production, and plasma levels of granulocyte elastase were measured in blood samples drawn sequentially within 8 h after the onset of ARDS (day 0), and then 24 (day 1), 72 (day 3), and 120 h (day 5) after the first sample; treatment with NAC or placebo was started immediately after day 0 and stopped just after day 3. Granulocyte GSH was significantly higher on days 1 and 3 when NAC was received by the patient. Unstimulated oxygen radical production, as measured ex vivo by luminol- and lucigenin-amplified chemiluminescence (CL), was higher in granulocytes from ARDS patients than from healthy control subjects, but was not influenced by NAC. The plasma levels of granulocyte elastase were five to eight times above the upper normal limit on day 0, decreased steadily until day 5, and were uninfluenced by NAC. In summary, parenteral NAC treatment started within 8 h of diagnosis increases the intracellular GSH in the granulocytes of ARDS patients without decreasing spontaneous oxidant production by these cells. The mechanisms of the protective effects of this drug previously reported in experimental and clinical ARDS remain to be established.

Objective measurement of lung function is considered essential in the management of patients with asthma and COPD. Many primary care practitioners lack the means necessary to obtain these measurements conveniently. To meet this need, electronic spirometers, offering portability, ease of operation, and timesaving readout options have been introduced. We compared the accuracy of a typical pneumotachograph-based device with a conventional volume displacement spirometer.

Studies investigating the relation between respiratory symptoms and change in ventilatory function have been limited by use of reported symptoms at a single point in time. To assess the relation between the longitudinal pattern of reported cough, phlegm, wheeze, and dyspnea and ventilatory loss, we prospectively investigated changes in FVC and FEV1 associated with development, resolution, or persistence of these symptoms over a 3- to 5-year period in 446 asbestos-exposed workers. Longitudinally reported symptoms changed frequently, with 52 to 61% of subjects reporting a specific symptom noting resolution or development of that symptom during follow-up. Initially reported symptoms were not predictive of accelerated loss of FVC or FEV1. In contrast, development of any new respiratory symptom, and to a lesser extent persistence of symptoms during follow-up, were associated with significantly greater ventilatory losses compared with asymptomatic individuals, ranging from 28 mL/yr in FEV1 for newly developed dyspnea, to 67 mL/yr in FVC for developed wheeze (p < 0.01). We conclude that development or persistence of respiratory symptoms over time, rather than the presence of symptoms per se, is predictive of future ventilatory loss. Recognition of interval changes in symptom reporting during surveillance of asbestos-exposed workers may effectively identify groups at risk for progressive ventilatory impairment.

To assess the effect of low dose dopexamine and dopamine on splanchnic blood flow as measured by gastric intramucosal pH, hepatic metabolism of lidocaine (lignocaine) to monoethylglycinexy-lidide (MEGX), and plasma disappearance rate of indocyanine green (ICG).

A significant minority of patients with COPD have favorable response to corticosteroid treatment. In addition, the benefit of corticosteroid treatment may be outweighed by the side effects. Long-term administration of inhaled steroids is a safe means of treatment. We hypothesized that treatment with high-dose inhaled budesonide would improve clinical symptoms and pulmonary function in subjects with COPD, and that the response to inhaled beta 2-agonist will serve to individualize steroid responders. We compared a 6-week course of 800 micrograms/d inhaled budesonide with placebo, separated by 4 weeks when no medication was taken, in a double-blind crossover trial, in 8 patients responding to inhaled beta 2-agonist, and in 22 nonresponders with stable COPD. In six of eight "responders to beta 2-agonist," there was a significant improvement in the FEV1 (defined as > or = 20%) following inhaled budesonide, as compared with placebo. In the 22 "nonresponders to beta 2-agonist," there was no significant improvement in the mean FEV1 (1.41 +/- 0.1 L before, and 1.61 +/- 0.1 L after treatment) with inhaled budesonide or placebo. Over the 6-week course of treatment by either budesonide or placebo, the nonresponders reported similar beta 2-agonist consumption (4.8 +/- 0.2 and 5.0 +/- 0.1 puffs per patient per day, respectively). However, there was a significant difference between the two periods of treatment in the responders as for the mean daily number of beta 2-agonist inhalations (2.4 +/- 0.1 in the budesonide period as compared with 5.3 +/- 0.1 in the placebo period; p < 0.005). We conclude that treatment with inhaled steroids improved spirometry data and inhaled beta 2-agonist consumption in about 25% of patients with stable COPD, and this rate is increased to about 75% in patients who respond to beta 2-agonist inhalation.

Pentoxifylline has been reported previously in an unblinded study to improve oxygen saturation, treadmill walk time, and resting diffusion of carbon monoxide (Dco) in patients with COPD. We recruited 12 patients with moderate to severe COPD whose exercise capacity was limited by ventilation or who developed hypoxemia with exercise. Patients were randomized to receive pentoxifylline or placebo, each for a 12-week period in a prospective, double-blind, crossover design study, to assess the effects of pentoxifylline on oxygenation, resting Dco, and exercise tolerance using arterial blood gas analysis. Eleven patients with a mean FEV1 of 0.94 L and a mean Dco of 9.85 mL/min/mm Hg completed the study. One patient withdrew from the study after developing pneumonia. There were no significant differences in resting oxygenation, resting Dco, or spirometry after 12 weeks of pentoxifylline relative to placebo. The 12-min walk test and dyspnea index for activities of daily living were also not significantly different while taking pentoxifylline. Finally, at maximal exercise, there were no differences in workload attained, exercise duration, oxygen consumption, carbon dioxide production, minute ventilation, oxygen saturation, PO2, alveolar-arterial oxygen pressure difference, or Borg score while taking pentoxifylline relative to placebo. We conclude that pentoxifylline does not improve oxygenation, resting Dco, exercise tolerance, or dyspnea in patients with moderate to severe COPD.

To test the hypothesis that acute lung injury during cardiopulmonary bypass (CPB) is related to the activation of neutrophils and the body temperature during bypass, we determined the differential WBC count, plasma elastase concentrations, and lung function before, during, and after CPB in 38 patients undergoing elective coronary artery bypass surgery. The patients were randomly assigned to receive either normothermic (n = 19, rectal temperature: 35.9 +/- 0.1 degrees C, mean +/- SE) or hypothermic (n = 19, 29.2 +/- 0.5 degrees C) CPB. The cellular response to the extracorporeal circulation was significantly delayed in the hypothermic group with a later onset of neutrophilia and a later increase in plasma elastase levels during bypass. Lung function deteriorated significantly after CPB as assessed by respiratory index, alveolar-arterial oxygen gradient, and intrapulmonary shunt, independent of bypass temperature. There was a positive correlation between peak elastase concentrations and postoperative respiratory index as well as intrapulmonary shunt (R2 = 0.5, p = 0.002 and R2 = 0.45, p = 0.003, respectively). Besides peak plasma elastase levels, multiple regression revealed no significant influence of other independent factors on postoperative lung dysfunction in our patients.

Cardiac rehabilitation in central Europe traditionally involves isolating patients in a residential idyllic setting where exercise is performed frequently but in a relatively unstructured fashion. Few studies have been performed on the effects of these programs among patients who have undergone bypass surgery. Recent data suggest that postbypass patients may enter these programs too soon after surgery or that exercise is not structured enough to distinguish the benefits of rehabilitation from those experienced by a control group.

Twice-daily inhaled salmeterol for 4 weeks produces marked reduction in its acute bronchoprotective effect against methacholine. This investigation examined the onset of this effect over 5 days, and also assessed cross-tolerance with salbutamol.

To compare the short-term effects of postural drainage with clapping (PD) and autogenic drainage (AD) on oxygen saturation, pulmonary function, and sputum recovery, we studied ten patients with cystic fibrosis (CF) randomly treated with PD or AD on separate days. Pulse oximetry was monitored and sputum was collected during and for 1 h following each treatment. Pulmonary function was measured before and then 1, 15, and 60 min after each treatment. There was no significant difference in the amount of sputum recovered with AD (14.0 +/- 3.5 g) vs PD (10.4 +/- 3.0 g) and no significant differences in pulmonary function occurred. Oxygen saturation during PD fell from 93.3 +/- 0.7% to 91.2 +/- 0.8% (p < 0.01) and required 15 min following treatment to return to baseline. Oxygen saturation did not fall during AD and increased to 94.5 +/- 0.7% by 1 h following treatment (baseline, 93.3 +/- 0.8%; p < 0.01). We conclude that AD is less likely to produce oxygen desaturation and may be better tolerated by patients with CF, while producing similar benefits in sputum clearance.

To define risk factors and optimum therapy for AIDS-related spontaneous pneumothorax (PTX).

A double-blind, placebo-controlled study using anistreplase was performed in 159 patients with unstable angina. All patients had a history of unstable angina combined with typical ECG changes and without evidence of a previous, recent, or ongoing myocardial infarction. The purpose of the present study was to analyze the relationship between the patency of the culprit artery and the behavior of the ischemia-related regional left ventricular (LV) wall motion.

The purpose of this study was to evaluate whether carbon dioxide (CO2) rebreathing occurs in acute respiratory failure patients ventilated using the standard airway management system (BiPAP pressure support ventilator; Respironics; Murrysville, Pa) with positive inspiratory airway pressure and a minimal level of positive end-expiratory pressure (PEEP) and whether any CO2 rebreathing may be efficiently prevented by the addition of a nonrebreathing valve to the BiPAP system circuit. In the first part of the study, the standard device was tested on a lung model with a nonrebreathing valve (BiPAP-NRV) and with the usual Whisper Swivel connector (BiPAP-uc). With the BiPAP-uc device, the resident volume of expired air in the inspiratory circuit at the end of expiration (RVEA) was 55% of the tidal volume (VT) when the inspiratory pressure was 10 cm H2O and the frequency was at 15 cycles per minute. The BiPAP-NRV device efficiently prevented CO2 rebreathing but resulted in a slight decrease in VT, which was due to a significant increase in external PEEP (2.4 vs 1.3 cm H2O) caused by the additional expiratory valve resistance. For similar reasons, both the pressure swing necessary to trigger pressure support and the imposed expiratory work were increased in the lung model when the nonrebreathing valve was used. In the second part of the study, seven patients weaned from mechanical ventilation were investigated using a randomized crossover design to compare three situations: pressure support ventilation with a conventional intensive care ventilator (CIPS), BiPAP system use, and BiPAP-NRV. When we compared the BiPAP system use with the other two systems, we observed no significant effect on blood gases but found significant increases in VT, minute ventilation, and work of breathing. These findings are experimental and are clinical evidence that significant CO2 rebreathing occurs with the standard BiPAP system. This drawback can be overcome by using a non-rebreathing valve, but only at the expense of greater expiratory resistance.

The purpose of this randomized prospective study was to assess the efficacy of local radiotherapy in preventing malignant seeding along invasive diagnostic procedures (cytology, needle biopsy, thoracoscopy, or chest tube placement) in patients with malignant pleural mesothelioma. Forty consecutive patients with histologically proven malignant mesothelioma were enrolled. Twenty patients received three daily sessions of radiotherapy at a dosage of 7 Gy 10 to 15 days after thoracoscopy. The other 20 patients did not receive radiotherapy. None of the 20 patients treated developed entry tract metastasis. In contrast, 8 of the 20 (40%) patients who were not treated developed metastases. These findings confirm the efficacy and safety of early local radiotherapy in preventing malignant seeding after invasive diagnostic procedures in patients with malignant pleural mesothelioma.

It has remained unclear whether bronchial responsiveness as measured by a single-step cold-dry air challenge (CACh) correlates closely to the responsiveness that is assessed by a routine pharmacologic challenge.

To evaluate the impact of a week-long course of inhaled albuterol compared with ipratropium on expiratory peak flow, exercise performance, and dyspnea in patients with stable COPD.

To assess the relationship of distance ambulated during the 6-min walk test (6'WT) to maximal oxygen consumption (VO2 max).

The effectiveness of nicotine gum in combination with a behavior modification program was studied. The nicotine dependence of participating smokers (N = 322) was assessed. One hundred sixty-eight smokers were labeled as high nicotine dependent and 154 as moderate to low dependent. In a randomized double-blind procedure, the high-dependent smokers were given gum containing 4 mg of nicotine (87) or 2 mg of nicotine (81) and the smokers with medium or low dependence were given gum containing 2 mg (76) or a placebo gum (78). The smokers were also randomized to familiarizing themselves with the medication a week before quit day (112) or to regular use, that is starting gum use on the quit day (122). In the high-dependent group, sustained and chemically verified nonsmoking rates at 6 weeks, 1 year, and 2 years were, respectively, 60%, 39%, and 34% in the subjects given the 4-mg dose compared with 41%, 16%, and 16% for those using the 2-mg dose. In the group with medium or low dependence, the success rates at the same time periods were 70%, 49%, and 39% for the subjects given the 2-mg dose and 38%, 22%, and 17% for those given placebo gum. The differences in success rates were significant at least at the p < 0.02% level for all comparisons. Familiarizing with the gum as compared with regular use gave fewer reports of side effects, 15% vs 34%, p < 0.001. A trend toward better success rates at 6 weeks, although not statistically significant, was observed for the familiarization group, 61% vs 52%. The study shows that high nicotine-dependent smokers need higher doses of nicotine replacement, in this case the 4-mg dose rather than the 2-mg dose, whereas 2 mg is superior to placebo among less dependent smokers. These results compare favorably with those reported from the more recent nicotine patch therapy.