Treatment of adult respiratory distress syndrome.

Adult respiratory distress syndrome (ARDS) culminates in inadequate oxygen delivery to the tissues. There are numerous inciting factors for this syndrome. Several therapies including the prophylactic use of antibiotics and steroids are controversial; even mechanical ventilatory support has controversial elements. The cornerstone of treatment remains supportive care until the cause of ARDS has resolved.

Theophylline in stable chronic airflow obstruction. A reappraisal.

Theophylline is commonly recommended for patients who have stable chronic airflow obstruction (CAO). Recent evidence confirms that serum theophylline concentrations between 10 and 20 mg/L may increase forced expiratory volume in 1 s (FEV1) and forced vital capacity in these patients. Exercise tolerance, however, and the classic respiratory symptoms of wheezing, breathlessness, cough, and sense of well-being do not improve. A reappraisal of the role of this medication in patients with stable CAO is therefore necessary; we recommend not prescribing this medication for all patients. Instead, the response of FEV1 after isoproterenol inhalation (0.15 mg) should be monitored. This simple test has good efficacy for predicting the response to oral theophylline therapy and could diminish the cost and unnecessary side effects of theophylline while benefiting those who will respond.

Trimethoprim-sulfamethoxazole-induced cholestatic hepatitis. Inadvertent rechallenge.

Trimethoprim-sulfamethoxazole is known to produce hepatitis. We report a case involving the inadvertent rechallenge with trimethoprim-sulfamethoxazole (Bactrim) in a patient with a previous episode of drug-induced hepatitis. A liver biopsy specimen showed both cholestatic and cytotoxic changes consistent with drug-induced damage. Comparison with existing cases is presented and an immunologic cause is considered.

Therapy of chronic obstructive airways disease.

The most frequently employed measure in attempts to alleviate symptoms and improve the quality of life of patients with chronic obstructive airways disease (COAD) is to prescribe medications. However, COAD is largely an irreversible condition and no therapeutic intervention has been shown to be universally useful. Theophylline or corticosteroid are occasionally helpful but most patients will not benefit. Of the remaining options, only oxygen has been shown to be effective in selected patients and should be administered on a continuous basis. It is becoming increasingly evident that clinicians should be more discriminating when making therapeutic decisions for persons with COAD. Maintenance therapy with pharmacological agents should be entertained only after individually conducted therapeutic trials. Moreover, enormous costs can result from treating even a small fraction of the population estimated to have COAD.

Are maximal inspiratory breathing exercises or incentive spirometry better than early mobilization after cardiopulmonary bypass?

Forty-nine adults who had undergone cardiopulmonary bypass surgery were randomly assigned to one of three exercise programs to determine if either maximal inspiratory breathing exercises or incentive spirometry offered a therapeutic advantage over early mobilization alone. After extubation, the patients started their assigned exercise programs. A physical examination and pulmonary function tests were performed preoperatively, at the start of the exercise program, and 24 and 48 hours after the start of the program. The results showed a significant decrease (approximately 50%) in lung volumes but no airflow obstruction in patients who had coronary artery bypass graft. In those patients who had valve replacement, lung volumes fell, and in addition, mild airflow obstruction occurred. A majority of patients had postoperative pulmonary complications. There were no significant differences among the exercise programs in improving lung volumes and airflow or in preventing postoperative complications. We conclude that maximal inspiratory breathing exercises or incentive spirometry, when used in addition to early mobilization, offers no therapeutic advantage over early mobilization alone after cardiopulmonary bypass surgery.

The pulmonary haemodynamic effects of almitrine infusion in men with chronic hypercapnia.

1. Almitrine, an agonist of peripheral chemoreceptors, has been shown to be effective in lowering PaCO2 in patients with chronic obstructive lung disease. The aim of this investigation was to evaluate the pulmonary haemodynamic response to almitrine in clinically stable patients with chronic airflow obstruction and chronic hypercapnia (PaCO2 7.1 +/- 0.5 kPa, mean +/- SD). 2. Seven men, aged from 55 to 64 years, had the following values for pulmonary function (means +/- SD): FEV1.0 0.67 +/- 0.16 litre; VC 2.12 +/- 0.52 litres; FEV1.0/VC 33 +/- 8%. They had haemodynamic monitoring during 1 h of almitrine (1 mg/kg intravenously) and solvent (placebo) in a random fashion while receiving 28% oxygen. Before infusion, six patients had evidence of pulmonary hypertension and the mean pulmonary artery pressure (PAP) for all seven patients was 4.3 +/- 1.6 kPa (mean +/- SD); the pulmonary vascular resistance (PVR) was 0.61 +/- 0.22 kPa 1(-1)s (mean +/- SD). 3. There were no significant changes from baseline values during placebo. During almitrine, however, the PAP and right ventricular stroke work (mean +/- SD) increased significantly at 30 min (6.0 +/- 2.1 kPa, P less than 0.001, 0.38 +/- 0.12 J, P less than 0.05, respectively) with maximum increase of PVR at 45 min (1.01 +/- 0.34 kPa 1(-1)s, P less than 0.001, mean +/- SD). The lowest PaCO2 (mean +/- SD) was observed at the end of the infusion (5.7 +/- 0.5 kPa, P less than 0.001). 4. These results confirm the benefit of almitrine in lowering PaCO2 in patients with chronic airflow obstruction who have chronic hypercapnia but also demonstrate significant pulmonary vasoconstriction.

The efficacy of isoproterenol inhalation for predicting the response to orally administered theophylline in chronic obstructive pulmonary disease.

Orally administered theophylline is commonly prescribed for patients with chronic obstructive pulmonary disease (COPD). It would be advantageous to predict those patients who will or will not respond to this methylxanthine. Forty men with COPD received placebo and theophylline orally, each for 1 month in a double-blind, single cross-over fashion. The acute response of the forced expiratory volume in one second (FEV1) to isoproterenol inhalation (015 mg) during placebo therapy was determined. The subjective and objective responses after 1 month of therapeutic theophylline concentrations (15.1 +/- 4.2 microgram/ml), mean +/- SD) in these clinically stable subjects also were measured. The sensitivity and specificity of isoproterenol aerosolization for predicting an objective response to theophylline was 75 and 96%, respectively. We conclude that isoproterenol inhalation can predict the response to orally administered theophylline in patients with COPD.

[Volumetric correction of the maximal expiratory flow 25-75% in chronic obstructive bronchopneumopathies]. / Correction volumétrique de débit maximum expiratoire 25-75% dans les bronchopneumopathies chroniques obstructives.

After inhalation of a bronchodilator aerosol, indices of airway obstruction usually improve whereas the forced expiratory flow between 25 and 75% (FEF25-75%) of the forced vital capacity (FVC) commonly remains the same or may decrease. This is due to the fact that the FEF25-75% after bronchodilatation is measured at lower absolute lung volumes with subsequently less elastic recoil pressure. A goal of this study was to analyze this test after volume adjusting so that the flows before and after a bronchodilator are compared at equal volumes (isovolume). Thirty-seven men with chronic obstructive pulmonary disease (COPD) performed maximal forced expiratory maneuvers before and 15 minutes after isoproterenol (0.15 mg) inhalation. The mean value of isovolume (0.56 +/- .30 1. sec-1) was significantly greater (p less than 0.001) than the FEF25-75% recorded before (0.45 +/- .26 1. sec-1) and after (0.50 +/- .27 1. sec-1, p less than 0.01) bronchodilator inhalation. The FVC was improved in 18 patients but only 6 (33%) had an improved conventional FEF25-75%. On the other hand, isovolume FEF improved in 12 (66%) patients. Isovolume FEF also improved twice as frequently as conventional FEF25-75% in those demonstrating an improvement in forced expiratory volume in the first second (FEV1). Furthermore, when the conventional FEF25-75% demonstrated no improvement after isoproterenol inhalation, isovolume improved in 8/26 (31%) of these patients. Our results suggest that volume adjusting the FEF25-75% after isoproterenol inhalation increases its sensitivity for detecting acute bronchodilation in patients with COPD, and that this methods appears practical in routine pulmonary function testing.

Isoproterenol challenge during placebo and oral theophylline therapy in chronic obstructive pulmonary disease.

Because it is common to perform a bronchodilator challenge while a patient continues oral methylxanthines, we wanted to determine if this procedure might be misleading for subsequent therapy. Thirty-eight men with a long smoking history and a clinical diagnosis of chronic obstructive pulmonary disease (COPD) were given placebo and oral theophylline (each for one month) in a double-blind, single-crossover manner. Pulmonary functional tests were performed before and after isoproterenol nebulization on the final day of each 4-wk period. There were significantly larger increases in FVC (p less than 0.001) and FEV1 (p less than 0.01) after isoproterenol challenge when receiving placebo than when receiving theophylline. According to the intermountain Area rating criteria, only the results after isoproterenol challenge during placebo therapy would indicate improvement. These results suggested that isoproterenol inhalation challenge be performed after methylxanthines have been discontinued if used to predict which patients with COPD may respond to oral theophylline therapy.

Treatment of chronic obstructive pulmonary disease with orally administered theophylline. A double-blind, controlled study.

Theophylline is commonly prescribed for chronic obstructive pulmonary disease (COPD), although controlled studies do not exist to support this use. We administered theophylline and placebo orally to 40 ambulatory COPD patients in a double-blind, crossover manner. Pulmonary function tests were conducted before and after isoproterenol nebulization on the final day of each four-week study period. Theophylline therapy produced small, but significant, increases over placebo in mean values. However, only the forced expiratory volume in 1 s was "improved," according to published criteria. There were no significant differences in subjective effects between treatment periods. Six patients were identified as "responders"; responder status could be predicted on the basis of improvement in flow rates after isoproterenol nebulization. Theophylline therapy is not beneficial to most COPD patients, and potential responders should be given carefully monitored therapeutic trials rather than arbitrarily being given maintenance therapy.

[The place of the chest radiograph in estimating total lung capacity (author's transl)]. / Place de la radiographie thoracique dans l'estimation de la capacité pulmonaire totale.

The determination of total lung capacity (TLC) by either the plethysmographic (pleth) or closed-circuit foreign gas (dil) method requires expensive and sophisticated equipment. Since hospitals usually have the facilities to perform chest roentgenograms, we wanted to ascertain if the radiologic method (rad) of BARNHARD et al. [1] could be used in lieu of the more sophisticated methods. Sixty-two men ranging from 21 to 67 years had TLC determined by the plethysmographic method, the closed-circuit foreign gas method in which rebreathing was continued until helium was uniformly distributed throughout the lungs, and the radiologic method. There were 21 normal men, 30 with a clinical diagnosis of chronic bronchitis and 11 with a radiologic diagnosis of emphysema plus chronic bronchitis. The mean value of TLC in the normal men showed no significant differences between the three methods and an excellent correlation between the pleth-rad and dil-rad. In the men with chronic bronchitis, there were no significant differences between the mean TLC of rad (7.166 +/- 1.217 1) and dil (6.704 +/- 1.067 1) of rad and pleth (7.545 +/- 1.165 1). The correlations (p < 0.001) were: dil-rad (r = 0.78) and pleth-rad (r = 0.77). In the men with emphysema, there were also no significant differences between the mean TLC of rad (7.166 +/- 1.217 1) and dil (6.704 +/- 1.067 1) or rad and pleth (7.545 +/- 1.165 1). The correlations (p < 0.001) were: dil-rad (r = 0.78) and pleth-rad (r = 0.77). In the men with emphysema, there were also no significant differences between the mean TLC of rad (8.789 +/- 1.207 1) and dil (7.831 +/- 1.041 1) or rad and pleth (9.403 +/- 1.735 1). The correlations were: dil-rad (r = 0.81, p < 0.01) and pleth-rad (r = 0.91, p < 0.001). This study suggests that in normal individuals and patients with chronic bronchitis or emphysema the radiographic method is a useful and reliable technique for determining TLC when elaborate equipment for measuring lung volumes is not available.

[The diagnosis of upper airway obstruction by flow-volume loops (author's transl)]. / Diagnostic de l'obstruction des voies aériennes sup"57erieures par les boucles débit-volume.

The recognition of upper airway obstruction (UAO) is occurring more frequently, especially after prolonged intubation for artificial ventilation. The diagnosis of UAO may be inferred by the clinical signs or spirometry; however, these methods are not reliable. We present 4 cases of UAO to illustrate the role of the flow-volume loop in securing the correct diagnosis. These cases demonstrate the utility of the flow-volume loop as a simple technique in confirming the presence of UAO.

Flexible fiberoptic bronchoscopy. An analysis of proficiency.

The purpose of this study was to determine the number of procedures necessary to become proficient in flexible fiberoptic bronchoscopic examination. I performed 99 bronchoscopic procedures during a formal training program under the direct supervision of instructors with varying experience. There were no statistical differences in the bronchoscopic accuracy among the instructors whose experience ranged from 100 to 4,000 bronchoscopic procedures. This implied that 100 procedures were necessary to become proficient in fiberoptic bronchoscopic examination. Immediately following the formal training program, I performed 35 consecutive bronchoscopic procedures without supervision. The diagnostic accuracy of these procedures was not statistically different from the accuracy during the training program. This study suggests that 100 flexible fiberoptic bronchoscopic procedures are sufficient to become proficient.

Needle aspiration biopsy in suspected pulmonary carcinoma.

The results of 22 needle aspiration biopsies performed over a period of 1 year were analyzed to help determine the role of this procedure in diagnosing suspected pulmonary carcinoma. The sensitivity for diagnosing pulmonary carcinoma was 79% while the specificity was 100%. The accuracy was greatest when the pulmonary mass was against the chest wall. This study suggests that needle aspiration biopsy has an important role in diagnosing suspected pulmonary carcinoma and is the procedure of choice when the mass is against the chest wall.

Bronchial secretion levels of amikacin.

Amikacin was given to 14 noninfected men as three consecutive intramuscular injections (7.5 mg/kg) at 12-h intervals. Serum and bronchial secretion specimens were obtained at various times during flexible fiberoptic bronchoscopy after the final dose. Serum and bronchial secretion concentrations obtained between 1.5 and 2.0 h after the final dose ranged from 17 to 40 mug/ml and 2.3 to 8.4 mug/ml with a mean of 23.7 +/- 2.9 and 5.23 +/- 1.5 mug/ml, +/-1 standard error of the mean, respectively. The highest bronchial secretion concentration in each subject correlated with the highest serum concentration (r = 0.83, P < 0.001), and all concurrent serum and bronchial secretion concentrations demonstrated a significant correlation (r = 0.82, P < 0.001). Clearance occurred at the same rate (half-life serum = 2.84 h; half-life of bronchial secretion = 2.60 h, P > 0.5). The mean bronchial secretion concentration of the 15 specimens obtained more than 7 h after the final dose was less than 1.0 mug/ml, with a range from 0.3 to 1.6 mug/ml. It is concluded that amikacin may achieve minimal inhibitory concentrations for many gram-negative bacteria in the bronchial secretions of noninfected patients 1 to 2 h after the final dose. However, levels fall below the reported minimal inhibitory concentrations against negative bacteria 6 to 7 h after the final dose. Furthermore, bronchial secretion levels may never reach the minimal inhibitory concentration against Pseudomonas aeruginosa.