1441. Single-dose effect of astemizole on bronchoconstriction induced by histamine in asthmatic subjects.
Astemizole, administered for seven days to asthmatic subjects, had an effect of bronchoconstriction induced by inhaled histamine for a mean period of 42 days. This study evaluates whether a single dose of astemizole would have the same effect.
1442. Adrenal function in adult asthmatics during long-term daily treatment with 800, 1,200, and 1,600 micrograms triamcinolone acetonide. Multicenter study.
作者: L C Altman.;S R Findlay.;M Lopez.;P Lukacsko.;R J Morris.;J L Pinnas.;P H Ratner.;S J Szefler.;M J Welch.
来源: Chest. 1992年101卷5期1250-6页
A study to assess the effect of the long-term use of triamcinolone acetonide (TA) on adrenal function was conducted with 143 male and female patients with asthma who were randomly assigned to receive 800, 1200, or 1,600 micrograms of TA daily for six months. Adrenal function was assessed prior to treatment and after two weeks and one, three, and six months of TA use. The effect of TA was evaluated by measuring plasma cortisol levels just prior to and 30 min after a bolus IV injection of 0.25 mg cosyntropin. Adrenal suppression was assumed if the plasma concentration of cortisol did not increase by at least 7 micrograms/dl from the prestimulation value, and remained below 18 micrograms/dl 30 min after the cosyntropin injection. Urine collected for 24 h prior to each cosyntropin stimulation was assayed for free cortisol and related metabolites to confirm suppression. Although all treatment regimens caused some reduction in the 24-h excretion of corticosteroid products, none of the mean values was below the normal ranges. The mean data indicate that TA had no significant effect on adrenal function at any dose or at any time for the patients overall. Individually, three patients exhibited some reduction in adrenal function.
1443. EAMI--exercise training in anterior myocardial infarction: an ongoing multicenter randomized study. Preliminary results on left ventricular function and remodeling. The EAMI Study Group.
作者: P Giannuzzi.;P L Temporelli.;L Tavazzi.;U Corrá.;M Gattone.;A Imparato.;A Giordano.;C Schweiger.;L Sala.;C Malinverni.
来源: Chest. 1992年101卷5 Suppl期315S-321S页
To determine the effects of a 6-month exercise training program on left ventricular (LV) function and remodeling, 49 consecutive patients (pts) with first Q anterior myocardial infarction (51 +/- 8 years), in I-II NYHA class, were studied 4 to 8 weeks after the acute episode and 6 months later by 2D-ECHO and upright bicycle ergometric test. At entry, pts were randomly allocated to physical training (T = 25pts) or control (C = 24pts). Global endocardial surface area (ESA), LV volumes and EF, extent of abnormal wall motion (%WMA), of regional dilatation (%REG DIL), and the shape distortion (DIST) index were analyzed. After 6 months, a significant increase in work capacity (4,589 +/- 1,417 to 5,379 +/- 1,485 KPM/min, p less than 0.03) and in lactic anaerobic threshold (45 +/- 13 to 63 +/- 15 W, p less than 0.01) was observed only in T. Initial ESA, EDV, EF, %WMA, %REG DIL, and DIST index were similar and they did not change after 6 months in both groups. However, pts with less than 40%EF had greater (p less than 0.0001) EDV and %WMA with marked DIST index at entry and showed further (p less than 0.01) deterioration after 6 months both in C and in T (EDV, ml/m2: 68 +/- 12 to 77 +/- 18 in C, 71 +/- 12 to 74 +/- 18 in T; %REG DIL: 39 +/- 20 to 49 +/- 24 in C, 32 +/- 12 to 35 +/- 23 in T; DIST index: 0.16 +/- 0.07 to 0.21 +/- 0.09 in C, 0.2 +/- 0.07 to 0.22 +/- 0.1 in T). These variables did not change in pts with greater than 40%EF. Thus, from these preliminary data, pts with less than 40%EF at entry are prone to further global and regional LV deterioration. Physical training does not seem to increase this spontaneous deterioration.
1444. Long-term adaptation of 24-h heart rate variability after myocardial infarction. The EAMI Study Group. Exercise Training in Anterior Myocardial Infarction.
作者: G Mazzuero.;P Lanfranchi.;R Colombo.;P Giannuzzi.;A Giordano.
来源: Chest. 1992年101卷5 Suppl期304S-308S页
To investigate the effects of physical training on neurovegetative profile of patients with previous anterior myocardial infarction (MI), we studied 38 patients out of the EAMI study at 4 to 6 weeks after anterior MI (test 1), who were then assigned randomly to a training group (n = 22) or to a control group (n = 16) and studied again 6 months later (test 2). Neurovegetative function was assessed by analyzing the heart rate variability (HRV) of 24 h, from ambulatory ECG recording, both in time domain, as standard deviation of sinus rhythm RR intervals (sdRR) and percentage of differences greater than 50 ms for successive sinus rhythm R-R intervals (pNN50), and in frequency domain, as low frequency (LF) and high frequency (HF) components of RR variability power spectrum. At test 1, HRV was almost in normal range or slightly decreased in few subjects. HRV increased on average at test 2: sdRR augmented significantly (p less than 0.05) without significant differences between training group and control group; mean LF/HF ratio increased slightly (p less than 0.05) at test 2. This might suggest a shift of neurovegetative balance toward a sympathetic rule, but the difference is too small and the patient population limited to reach firm conclusions. Analysis of 24-h dynamics of HRV in single patients showed different patterns and different adaptations during the time course of 6 months after anterior MI.
1445. Autonomic nervous system adaptations to short-term exercise training.
Signs of sympathetic hyperactivity and low parasympathetic activity have been found during the acute and recovery phases of myocardial infarction and have been associated with an increased risk of cardiac mortality. Beneficial effects of physical training have been recently reported in post-myocardial infarction patients. We tested the hypothesis that physical training would be effective in improving the autonomic balance by studying 22 patients with a first and recent myocardial infarction who were randomly assigned to enter or not enter a 4-week in-hospital physical training program. Spectral indices of heart rate variability were analyzed at rest and during 70 degrees head-up tilt before and after the index training, not training period. As expected, physical training induced a significant increase in exercise duration (13.7 +/- 0.8 vs 17.1 +/- 0.1 min, p less than 0.001) and in the anaerobic threshold (9.5 +/- 0.7 vs 12.0 +/- 1.0 min, p less than 0.02) in trained patients, while no changes were observed in the untrained group. At entry, in both groups, spectral profile of heart rate variability was characterized by a predominant LF component and a smaller HF component with no further modification after head-up tilt. After 4 weeks, in resting conditions, no significant changes in spectral components were observed in both trained and untrained patients. After physical training, head-up tilt produced significant modifications in spectral profile with an increase in the LF component (84 +/- 3 vs 69 +/- 5 nu, p less than 0.01) and a decrease in the HF component (7 +/- 1 vs 19 +/- 4 nu, p less than 0.05) in trained patients, while no changes were observed in the untrained patients. Our data suggest that in postmyocardial infarction patients, 4 weeks of physical training may induce an improvement in the autonomic balance with a restoration toward normal in the reflex activity of the system.
1446. Ventilatory and metabolic changes as a result of exercise training in COPD patients.
Patients with COPD feel better and are able to sustain a given level of activity longer after a program of exercise training, but the underlying physiologic mechanisms have not been completely elucidated. Since the physical performance of patients with COPD is limited mainly by pathophysiologic derangements of the ventilatory system, the exercise performance can be ameliorated by increasing the level of ventilation that they can sustain or by reducing the ventilatory requirement for a given level of activity. Almost all studies have yielded negative results in patients with COPD in terms of exercise training having the ability to improve VEmax. The only way to reduce the ventilatory requirement is to reduce CO2 output. Lower levels of lactate result in less nonmetabolic CO2 produced by bicarbonate buffering and this is the likely mechanism responsible for a lower ventilatory requirement for work rates above the pretraining anaerobic threshold. We specifically wished to determine whether a program of intensity, frequency, and duration known capable of producing a physiologic training effect in healthy subjects would do so in patients with COPD. Further, we sought to determine whether exercise training at a work rate associated with lactic acidosis is more effective in inducing a training effect in patients with COPD than a work rate not associated with lactic acidosis. Nineteen patients with COPD were selected and performed an incremental test as well as 2 square wave tests at a low and a high work rate. Identical tests were performed after an 8-week program of cycle ergometer training either for 45 min/day at a high work rate or for a proportionally longer time at a low work rate. For the high work rate training group, identical work rates engendered less lactate (4.5 vs 7.2 mEq/L) and less VE (48 vs 55 L/min) after training; the low work rate training group had significantly less lactate and VE decrease (p less than 0.01). Further, in the first group, there was an increase in exercise tolerance averaging 71% in the high constant work rate test. There was a good correlation (r = 0.73, p less than 0.005) between the decrease in blood lactate and the decrease in ventilation. The major findings of this study are that patients with COPD who experience lactic acidosis during exercise can achieve physiologic training responses from a program of endurance training and that training work rates engendering high levels of blood lactate are more effective than work rates eliciting low lactate levels.
1447. The benefit of graded physical exercise in chronic heart failure.
A new program of rehabilitation is less demanding on cardiac output than standard programs. Twenty-five patients with chronic heart failure (ejection fraction [EF]: 0.26 +/- 0.10) were randomized into 2 groups: a control group with 13 patients and a rehabilitation group of 12 patients. In the control group, 2 did not complete the study (cancer, cardiac transplantation). For the 11 others, the different parameters studied were comparable at day 0 with group R and did not significantly change over 3 months outside of a spontaneous improvement in endurance performance by 22%. In the rehabilitation group (40 sessions over 90 days; specialized equipment) there were no incidents. Tolerance was excellent (heart rate during sessions less than 115 bpm) and all functional parameters improved. Training did not modify the isotopic ejection fraction. The quality of life score increased respectively by 52% (p less than 0.0001 in comparison with the control group) and by 63% (p less than 0.0001); 80% of the patients requested that training be prolonged. The functional improvement obtained by purely peripheral effect had no adverse effect on the heart.
1448. Is survival in acute myocardial infarction related to thrombolytic efficacy or the open-artery hypothesis? A controversy to be investigated with GUSTO.
The reduction in morbidity and mortality associated with thrombolytic therapy in patients with acute myocardial infarction was initially attributed to early restoration of arterial patency, salvage of ischemic myocardium, and preservation of left ventricular function. Recombinant tissue plasminogen activator (rt-PA) was initially the favored thrombolytic agent because of selected studies showing superior early patency rates. Interestingly, averaged results of studies using conventional dosing regimens show 90-min patency rates for streptokinase, rt-PA, and anisoylated plasminogen streptokinase activator complex (APSAC) to be 53%, 68%, and 72%, respectively, suggesting that previous claims exaggerated differences in early patency. More recently, it was found that administering the full 100-mg dose of rt-PA within 90 min increased 90-min patency rates to approximately 85% and that infusing rt-PA plus urokinase or streptokinase halved reocclusion rates. These results again suggest the unrealized potential of rt-PA to offer a unique clinical benefit. However, three important recent trials have challenged the concept that early patency conveys a survival benefit by showing no difference in mortality in patients treated with different thrombolytic agents. Other trials have shown survival benefit in patients in whom patency of the infarct artery was achieved in a time frame beyond that in which myocardial salvage could be expected. The "open-artery hypothesis" suggests that survival may be more dependent on improved left ventricular remodeling and healing, increased electrical stability, and better myocardial perfusion than on infarct size reduction. In an attempt to determine whether 90-min patency or 24-h patency is more predictive of survival, the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) trial will randomize approximately 40,000 patients to (1) streptokinase and subcutaneous heparin; (2) streptokinase and intravenous heparin; (3) front-loaded, weight-adjusted rt-PA and intravenous heparin; or (4) the combination of streptokinase and rt-PA and intravenous heparin.
1449. Angiotensin-converting enzyme inhibitors in patients with bronchial responsiveness and asthma.
Twenty-one subjects with known bronchial hyperreactivity were prospectively randomized in double-blind fashion to receive one of two angiotensin-converting enzyme inhibitors (ACE-I), enalapril or spirapril, for three weeks. Spirometry and methacholine provocation were performed prior to, during, and following ACE-I usage. Three of 21 subjects developed a nonproductive cough. However, only one subject wheezed slightly. Spirometry and bronchial reactivity (PD20) were unchanged throughout the study.
1450. Acute effects of oxygen administration on transmural pulmonary artery pressure in obstructive sleep apnea.
In order to investigate the role of hypoxia on the cyclic oscillation of transmural pulmonary artery pressure (PAP) in obstructive sleep apnea, oxygen was administered during one half of the night to six patients affected by obstructive sleep apnea syndrome during a nocturnal polysomnographic study. In each patient, transmural PAP measurements were performed on 15 randomly selected apneas recorded while breathing room air, and on 15 during O2 administration. During O2 administration in all patients, apneas were associated with a higher oxyhemoglobin saturation (SaO2), a smaller SaO2 swing, and a higher transcutaneous PCO2. The mean highest level of transmural PAP in the apneic episodes, commonly reached at their end, was significantly lower than while breathing room air in only two patients; however, due to a decrease in the mean lowest PAP level (at the beginning of apneas), the extent of the PAP increase within apneas did not differ between air and O2 breathing; these patients showed the smallest increase in transcutaneous PCO2 in our sample. End-apneic transmural PAP during O2 administration was significantly higher in one subject (for systolic values) and was not significantly different in the remaining three subjects. The extent of the increase in transmural PAP within apneas was greater in one patient; it was smaller in another one, but only for the diastolic values; and it did not differ significantly with respect to the value observed while breathing room air in all of the other subjects. The results suggest that hypoxia in obstructive apneas, at least in some patients, may lead to a steady increase in PAP, detectable both at the beginning and at the end of the episodes; conversely, the increase in PAP within apneas does not seem to be influenced by the simultaneous decrease in SaO2.
1451. Formoterol, a new long-acting beta 2 agonist, inhaled twice daily, in stable asthmatic subjects.
To determine whether formoterol, a new beta 2 agonist with experimentally documented long duration, is clinically more effective than salbutamol in the maintenance treatment of chronic asthma.
1452. Theophylline in obstructive sleep apnea. A double-blind evaluation.
Twelve patients with documented obstructive sleep apnea were enrolled in a double-blind placebo controlled crossover trial of oral theophylline, (Uniphyllin) 800 mg, taken at night for four weeks. Overnight polysomnography, using standard techniques, was performed at the end of each treatment period. The total number of apneas (A) and hypopneas (H) decreased significantly while receiving theophylline compared to placebo, from 398 (69), mean (SEM), to 283 (72), p less than 0.01. Sleep quality was, however, significantly worse while receiving theophylline. Obstructive A and H were very much decreased with theophylline (p less than .001), and even when the data were adjusted for the more disturbed sleep with theophylline, this decrease remained significant; the obstructive A and H index fell from 49 (8.7) on placebo to 40 (9) while receiving theophylline, p = 0.02. There was no difference in the numbers of central or mixed A and H, and mean A and H duration was unchanged on the two study nights. Oxygen desaturations greater than 4 percent were less with theophylline treatment (p = 0.02), but mean overnight SaO2 was unchanged. We conclude that theophylline may be beneficial in patients with OSA, but part of the improvement is due to a deterioration in sleep quality.
1453. The effects of acetazolamide on the ventilatory response to high altitude hypoxia.
Acetazolamide treatment ameliorates the symptoms of AMS; however, the mechanism by which this occurs is unclear. To examine the effects of acetazolamide on oxygenation, CO2 responsiveness and ventilatory pattern during acute exposure to HA, we studied two groups of subjects at SL and following rapid (less than 8 h) transport to HA. Acetazolamide or placebo tablets were given to groups 1 and 2, respectively, in a double-blind manner after baseline SL measurements; treatment was continued during HA exposure. There was no difference in the ventilatory pattern at HA, between the two groups. While the Ve achieved in response to CO2 at HA vs SL was much greater in each group the percent change from baseline at HA versus that at SL was not significantly different. The beneficial effects of acetazolamide in AMS are associated with a higher level of ventilation at HA and better oxygenation: CO2 chemosensitivity is not affected by acetazolamide at HA.
1454. Effects of the addition of nedocromil sodium to maintenance bronchodilator therapy in the management of chronic asthma.
To assess the efficacy and safety of nedocromil sodium metered dose aerosol as an adjunct to sustained-released theophylline therapy in adult theophylline-dependent asthma patients and to examine the ability of nedocromil sodium to substitute for theophylline.
1455. Postthoracotomy respiratory muscle mechanics during incentive spirometry using respiratory inductance plethysmography.
We undertook this study to characterize the postthoracotomy compartmental displacement and respiratory mechanical changes occurring during and after the performance of the incentive spirometry maneuver. We also evaluated the effect of recumbency angle on compartmental recruitment. Sixteen patients were randomized to perform incentive spirometry either at 30 degrees or 60 degrees recumbency angle. They were studied using respiratory inductance plethysmography to measure tidal volume, respiratory frequency, inspiratory time, rib cage motion/tidal volume ratio, inspiratory duty cycle, and inspiratory flow. Patients were studied before surgery and on postoperative days 1 and 3. Statistical analysis was accomplished using multiple measures ANOVA with post-hoc Student's t-tests when appropriate. Preoperative incentive spirometry augmented VT by increasing both VT/TI and TI. Postoperatively, the incentive recruitment of VT was reduced, a result of a decrease in TI and TI/TTOT; VT/TI was unchanged. There was postoperative decrease of AB and AB/VT during incentive spirometry, greatest in the 60 degrees group. Our results characterize the nature of the respiratory recruitment afforded by incentive spirometry, before and after thoracotomy. We also found evidence of postthoracotomy diaphragmatic derecruitment during incentive spirometry exacerbated by a high recumbency angle.
1456. The effects of verapamil on training in patients with ischemic heart disease.
Verapamil is a calcium-channel blocking agent with antianginal and antiarrhythmic properties that have been widely studied. Its myocardial depressant effect is well known. The purpose of this study was to examine the effects of verapamil on the training response in patients with ischemic heart disease. The study group consisted of 41 male patients with a mean age of 53.3 +/- 7.2 years who had suffered a myocardial infarction or had undergone coronary artery bypass surgery 8 to 12 weeks previously. They were chosen on a consecutive basis from eligible patients entering a cardiac rehabilitation program. With use of a double-blind technique, 21 patients were assigned to receive verapamil, 120 mg three times daily, while the other 20 were given an identical placebo. Each patient underwent exercise stress testing in the untreated state to permit comparison between tests performed on commencement and completion of training. The training effect was determined by comparing exercise response before and after the eight-week program. There was an increase in exercise duration (p less than 0.001) and a decrease in functional aerobic impairment (p less than 0.001), without difference between the two groups. Energy expenditure increased in both groups, but the highest level was achieved by those receiving active treatment (p less than 0.02). Heart rate for equal workload was significantly reduced after training (p less than 0.001), although this was lower in the placebo patients (p less than 0.001) and the patients who had a recent myocardial infarction (p less than 0.01). It appears that treatment with verapamil does not impair the development of a training effect in patients with ischemic heart disease who are undergoing organized training.
1457. Physiologic evaluation of pressure support ventilation by nasal mask in patients with stable COPD.
We evaluated the physiologic effects of pressure support ventilation by nasal route (NPSV) in eight patients with severe stable COPD and chronic hypercapnia who were randomly submitted to 2-h sessions of NPSV both with a portable ventilator (Respironics BIPAP device) and with a standard ventilator (Bird 6400ST device) at an inspiratory airway pressure of 22 cm H2O. Two sessions with each ventilator were performed using an FIO2 of 0.21 in each patient on two consecutive days. One patient did not tolerate either form of ventilation. Comparison of spontaneous with BIPAP ventilation showed a significant improvement in pH, PaCO2, and PaO2. Ventilatory pattern assessed by a respiratory inductive plethysmograph showed a significant increase in minute ventilation (VE), VT, and Ttot. Integrated surface diaphragmatic EMG activity measured only during BIPAP device ventilation decreased from that measured during spontaneous breathing. Similar changes in blood gases and ventilatory pattern were observed during ventilation by the Bird 6400ST except for VT/Ti ratio, which significantly increased. Comparison of baseline with measurements performed 12 h after the whole cycle of treatment showed a significant increase in pH and VE and a decrease in PaCO2. We conclude that short-term NPSV may be useful in improving respiratory pattern and blood gases in stable COPD patients with chronic hypercapnia.
1458. Relative amount of albuterol delivered to lung receptors from a metered-dose inhaler and nebulizer solution. Bioassay by histamine bronchoprovocation.
The results of previous studies comparing bronchodilatation from beta agonists administered by metered-dose inhaler (MDI) and nebulizer solution have been conflicting. We therefore evaluated a range of albuterol doses administered by these two methods, using histamine bronchoprovocation as a bioassay for the amount of drug reaching the beta 2 receptors in the lung. Twelve stable asthmatic volunteers received, in a double-blind, randomized, crossover design on different days, placebo or one, two, four, or six puffs from an MDI attached to an InspirEase device (90 micrograms per puff) or 0.625, 1.25, 2.5, or 5.0 mg of solution delivered in 2 ml of buffered saline through a Hudson Updraft II nebulizer. The histamine concentration required to decrease FEV1 by 20 percent (PC20) was measured 1 h before and 30 min after administration of each treatment and expressed as the increase in PC20 from baseline. The dose-response curves for change in PC20 indicated that the higher doses of the nebulizer solution delivered more drug to beta 2 receptors in the lung than the lower doses from the MDI. For example, the geometric mean increase in PC20 was 1.1 +/- 1.6 (SD) after placebo, 7.5 +/- 2.7 after two puffs from the MDI, and 20.0 +/- 2.1 after 2.5 mg of nebulizer solution (p less than 0.05). Using this bioassay method and administration technique, we estimated that ten puffs from the MDI (0.9 mg) would deliver approximately the same amount of albuterol to lung receptors as 2.5 mg of the nebulizer solution. Taking into account previously published reports and the results of the present study, we conclude that differences in dose, administration technique, nebulizer system efficiency, and severity of airway obstruction can alter the amount of drug reaching the beta 2 receptors in the lungs and, thus, the clinical response.
1459. Calcium inhibits the cardiac stimulating properties of dobutamine but not of amrinone.
作者: J F Butterworth.;G P Zaloga.;R C Prielipp.;W Y Tucker.;R L Royster.
来源: Chest. 1992年101卷1期174-80页
To contrast the effect of increasing blood calcium concentrations on the cardiovascular actions of intravenous beta-adrenergic agonists and phosphodiesterase inhibitors, 46 patients recovering from aortocoronary bypass surgery received either dobutamine or amrinone both in the presence and absence of a calcium infusion. Cardiac output, systemic arterial pressure, pulmonary arterial pressure, central venous pressure, pulmonary artery occlusion pressure, heart rate, and blood ionized calcium concentration were measured before and during infusions of dobutamine (2.5 and 5.0 micrograms/kg/min) and amrinone (0.75 mg/kg bolus + 10 micrograms/kg/min or 2.25 mg/kg bolus + 20 micrograms/kg/min). After the initial dobutamine infusion period, patients were randomly and blindly assigned to receive either a calcium or placebo infusion, and the dobutamine infusions were repeated. Because of the long duration of amrinone's actions, the amrinone maintenance infusion was continued while randomized, blinded infusion of either calcium or placebo was added. Dobutamine (5 micrograms/kg/min) increased cardiac output from 7.1 +/- 0.3 L/min to 9.1 +/- 0.4 L/min, and increased heart rate from 93 +/- 4 beats/min to 107 +/- 4 beats/min. Systemic vascular resistance decreased and stroke volume increased. Dobutamine had no significant effects on other hemodynamic values. Amrinone (2.25 mg/kg bolus + 20 micrograms/kg/min) increased cardiac output from 5.6 +/- 0.4 L/min to 6.9 +/- 0.5 L/min, and increased heart rate from 87 +/- 3 beats/min to 98 +/- 3 beats/min. Amrinone decreased mean arterial pressure, systemic vascular resistance, pulmonary artery occlusion pressure, central venous pressure, and pulmonary artery pressure. Calcium infusion increased arterial pressure (8 to 13 percent) but had no significant effects on any other hemodynamic parameters. Calcium reduced the increase in cardiac output produced by dobutamine by 30 percent, but it did not alter the cardiotonic actions of amrinone. Thus, calcium inhibits the cardiotonic actions of certain beta-adrenergic agonists, most likely by interfering with signal transduction through the beta-adrenergic receptor complex.
1460. Theophylline and salbutamol improve pulmonary function in patients with irreversible chronic obstructive pulmonary disease.
To investigate the efficacy of bronchodilators in patients with irreversible chronic obstructive pulmonary disease (COPD), we conducted a double-blind, randomized, four-phase, crossover comparison between placebo, oral theophylline, inhaled salbutamol, and a combination of both drugs in 12 patients with stable COPD (mean age, 63 years) whose increase in forced expiratory volume in 1 s (FEV1) was less than or equal to 15 percent following 200 micrograms of inhaled salbutamol. Patients received two weeks of therapy with each of the test regimens. Both theophylline and salbutamol resulted in statistically significant improvement in FEV1, forced vital capacity (FVC), slow vital capacity (SVC), residual volume (RV), airway resistance (Raw), and maximum expiratory flow rate at 50 percent of vital capacity (V50). In most instances, there were no significant differences between theophylline and salbutamol. Combination therapy produced significantly greater improvement in FEV1, FVC, V50, Raw, and RV than either agent alone. The two drugs interacted in an additive fashion. Neither of the drugs, used singly, significantly reduced the severity or incidence of symptoms. The reduction in dyspnea and wheeze during combination therapy approached statistical significance (p = 0.06) and patient preference was significantly in favor of the combination regimen. None of the active treatments produced significantly more side effects than placebo. We conclude that theophylline and inhaled salbutamol produce significant, and approximately equal, improvement in pulmonary function in patients traditionally classified as suffering from "irreversible" COPD. The combination of theophylline and inhaled salbutamol generally results in additional improvement over that obtained with either drug used alone and this improvement is reflected by reduced symptomatology and treatment preference.
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