Long-term treatment of chronic bronchitis with chest physiotherapy with or without positive expiratory pressure (PEP) by mask was studied in 43 patients randomly allocated to PEP treatment (PEP group, 20 patients) and conventional chest physiotherapy (control group, 23 patients). After instruction, the treatments were self-administered twice daily for 12 months (34 patients) and 5 months (9 patients). Twice weekly, patients filled in a diary concerning symptoms. The PEP group had significantly less cough and less mucus production. The number of acute exacerbations were calculated from the diaries and were lower in the PEP group compared to the control group, and 85 percent of the patients in the PEP group were free from acute exacerbations versus 48 percent in the control group. The PEP group also used less antibiotics and mucolytics. The PEP group had a small increase in FEV1 of mean 62 ml compared to a small decrease of 43 ml for the control group. Treatment with a simple PEP device can reduce morbidity in patients with chronic bronchitis and may preserve lung function from a more rapid decline.

Thirteen patients with acute pulmonary embolism were treated in a randomized double-blind fashion either with recombinant tissue plasminogen activator (rt-PA) 40 to 80 mg, usually in combination with heparin, or with placebo plus heparin. The drug was administered intravenously over 40 to 90 minutes. Nine patients received rt-PA, and four received placebo. A lytic effect was observed 1.5 and three hours after the onset of therapy with rt-PA based upon elevated levels of fragment-D dimers. Among the patients who received rt-PA, there was a modest improvement of the total pulmonary resistance 1.5 hours after the start of therapy, but the angiograms showed no significant changes in two hours. After 24 hours, the lung scans showed a trend toward greater improvement with rt-PA, but the rate of improvement in comparison to control subjects was not statistically significant. Massive bleeding occurred in one patient. The observations in this study suggest that rt-PA has little effect in two hours on angiographic clot burden, but may produce some improvement in hemodynamics. The treatment, however, is not without risk.

The bronchodilator effects were compared in 16 stable asthma patients for 12 hours after either 12 micrograms formoterol or 200 micrograms salbutamol from a metered-dose aerosol in a randomized, double-blind, crossover study. The FEV1 measured before 1, 2, 4, 6, 8, 10 and 12 hours after administration was used as the parameter. From 2 hours onwards after dosage, the bronchodilator effect of formoterol was statistically significantly greater than that of salbutamol. The effect of formoterol lasted longer, and even after 12 hours, the FEV1 was still 20 percent above the baseline value. This is clinically significant and offers new possibilities for treatment of the so-called "morning dip." Both agents were well tolerated.

High airway pressure may be injurious to lung parenchyma, but lowering airway pressure using conventional mechanical ventilation necessitates lowering tidal volume (VT). Intubated patients in the surgical intensive care unit (SICU) were randomly assigned to group 1 (VT = 12 ml/kg, n = 56) or group 2 (VT = 6 ml/kg, n = 47). Variables recorded included acute physiology and chronic health evaluation (APACHE II) score, mean peak airway pressure (MPAP), mean PaO2/FIO2, incidence of pulmonary infectious complications (PIC), duration of intubation (DOI), and duration of SICU stay (DOS). Results in the table are means +/- SE. (table; see text) The incidence of pulmonary infection tended to be lower and DOI and DOS tended to be shorter for nonneurosurgical and noncardiac surgical patients randomized to low VT, suggesting that morbidity may be decreased. The use of low VT was associated with a statistically significant but clinically irrelevant decrease in oxygenation. The routine use of low VT appeared to be safe in a selected population of patients in the SICU.

The efficacy of ipratropium and salbutamol was determined in 117 patients with acute asthma who presented to an emergency department to determine whether the order of administration of the two agents affects the improvement in peak flow rates. Patients were given two nebulized treatments at an interval of one hour in a randomized, double-blind design. They received either 5 mg nebulized salbutamol followed by 0.5 mg ipratropium, ipratropium followed by salbutamol, or both drugs administered together followed by nebulized saline. Ipratropium was an effective bronchodilator when given as the first agent. Simultaneous administration with salbutamol was as effective as sequential administration. At one hour after treatment, there was no difference in peak flow between the combination of drugs and either drug given alone. Ipratropium given after salbutamol was not superior to saline solution given after the combination of drugs. Our data do not suggest a substantial therapeutic effect from addition of ipratropium to salbutamol in the immediate treatment of acute asthma.

Pulse flow oxygen administered during early inspiration is a promising approach to oxygen conservation. Previous short-term studies show equivalent arterial PO2, 55 to 60 percent oxygen savings, and no reduction of nasal humidity when compared with continuous flow nasal cannula oxygen. This study compares the clinical efficacy of pulse flow and continuous flow oxygen in 100 patients recently hospitalized for diseases requiring O2 therapy. In an unblinded crossover design, pulse and continuous O2 were administered alternately during four 51/2-hour periods. Oxygen saturation was monitored continuously during the 23-hour study. Mean SaO2 on pulse flow (95.6 +/- 2.7 percent) was clinically the same as continuous flow (95.3 +/- 2.6 percent). Mean SaO2 on pulse flow during the 30 minutes before or after each crossover (95.5 +/- 3.3 percent) was similar to continuous flow during the 30 minutes near crossover (95.3 +/- 3.1 percent). It is concluded that the two delivery systems produce similar levels of SaO2 over the course of a day and night. Analysis of potential cost savings achieved by use of the device for a 350-bed hospital suggests a savings of about $50,000 yearly when accompanied by termination of oxygen humidification.

Seventy-four pulmonologists and one allergist were recruited to assess the efficacy and safety of iodinated glycerol (Organidin), 60 mg qid, vs placebo in patients with stable chronic obstructive bronchitis in a randomized, double-blind, placebo-controlled, parallel design. A total of 361 patients (180 to iodinated glycerol and 181 to placebo) who complained of cough and difficulty bringing up sputum entered the eight-week study. Evaluations were based upon eight primary symptom efficacy parameters (cough frequency, cough severity, chest discomfort, dyspnea, ease in bringing up sputum, patient and physician global assessments, and a derived patients' global assessment), and six secondary parameters (frequency of aerosol bronchodilator use, incidence and duration of acute exacerbations, frequency of concomitant medication use, incidences of adverse experiences and dropouts). Cough frequency, cough severity, chest discomfort, patients' ease in bringing up sputum, patients' overall condition, and a derived subject global assessment were significantly (p less than 0.05) improved by iodinated glycerol as compared with placebo within eight weeks of treatment. Dyspnea showed a trend toward improvement and the physicians' global evaluation showed no significant difference between groups. Similar findings were noted in a subgroup analysis of moderately-to-severely affected patients. The mean duration (days) of acute exacerbations and number of dropouts attributable to adverse experiences were significantly less (p less than 0.05) in the iodinated glycerol group.(ABSTRACT TRUNCATED AT 250 WORDS)

To determine a change in theophylline pharmacokinetics during concomitant thiabendazole or mebendazole therapy, we studied six normal, healthy male volunteers. Aminophylline was administered intravenously, followed by a 30-h blood sampling period. Subjects were randomized to receive thiabendazole or mebendazole, then crossed over to receive the other therapy. Theophylline concentrations were measured utilizing an HPLC technique and a one-compartment model was fit to the data. Theophylline pharmacokinetic parameters were significantly different during thiabendazole therapy. Mean theophylline half-life increased, clearance decreased and elimination rate constant decreased. Two subjects experienced severe nausea and vomiting during thiabendazole therapy. There were no significant differences in theophylline pharmacokinetic parameters during mebendazole therapy. Thiabendazole administration results in a significant decrease in theophylline clearance and beta elimination rate constant. The theophylline half-life increased significantly. Concomitant administration of theophylline and thiabendazole resulted in severe nausea and vomiting. Mebendazole administration did not seem to alter theophylline pharmacokinetics.

A prospective, randomized, controlled study was undertaken to compare the Pall Ultipor breathing circuit filter (PUBCF), a heat-and-moisture exchanger, and heated hot water systems (HHWSs) in ICU patients submitted to controlled mechanical ventilation. Humidification of inspired gas and bacterial contamination of breathing circuits were evaluated. During the study, there were six episodes of tracheostomy tube (TT) occlusion in six patients included in the PUBCF group. No patient out of 42 included in the HHWS group experienced this complication (p less than 0.01). There were 4 percent of days with thick and tenacious bronchial secretions in the PUBCF group and no case in the HHWS group (p less than 0.02). In the PUBCF group, 23 percent of days with hypothermia were noted as opposed to 12 percent in the HHWS group (p less than 0.01). Fewer breathing circuits were found to be contaminated in the PUBCF group (11 percent) than in the HHWS group (54 percent, p less than 0.01). In patients with an organism growing in bronchial specimens, the same organism was found to contaminate the breathing circuit in 10 percent of cases in the PUBCF group and 77 percent of cases in the HHWS (p less than 0.01). We conclude that, in the conditions of this study, the PUBCF did not provide sufficient humidification of inspired gas in ICU patients. Protection against contamination of breathing circuits was effective, but 10 percent of patients remained at risk for this complication.

We tested the hypothesis that the incidence of LRTI in critically ill blunt trauma victims can be reduced by employing continuous postural oscillation. Within 24 h of admission to the SICU, 106 patients were prospectively randomized to either a conventional bed or a RRKTT. Seven patients who were discharged from the SICU in less than 24 h were excluded from the data analyses. Until discharge from the SICU, patients were monitored daily for development of LRTI or pneumonia. Among 48 patients in the control group, 28 met criteria for LRTI and 19 met criteria for pneumonia. Among 51 patients in the RRKTT group, 13 developed LRTI and 7 developed pneumonia. The differences between groups for all LRTI and pneumonia were both significant. We conclude that continuous postural oscillation decreases the risk of pulmonary sepsis in victims of major blunt trauma.

Bronchial histamine provocation tests were performed in nine patients with nonallergic asthma on four consecutive days 45 minutes after inhalation of placebo or ipratropium bromide in a dose-response manner (40 micrograms, 200 micrograms, and 800 micrograms). The drugs were administered double-blind, one dose on each day. This procedure was repeated identically after three to nine months to investigate whether the bronchial responses to ipratropium bromide are constant or change with time. Ipratropium bromide induced a significantly better bronchodilation and protection against histamine-induced bronchoconstriction than placebo with no differences between the three doses. No correlation between bronchodilatation and protection was found. In six asthmatic patients ("responders") ipratropium bromide induced a significant protective effect against histamine-induced bronchoconstriction but no dose-response relationship was found. In three patients none or a very poor protective effect was found at all dose levels ("nonresponders"). The protective effect of ipratropium bromide against histamine-induced bronchoconstriction did not differ between the first and second occasion. Thus, the bronchoprotection differed between different asthmatic subjects but did not vary with time (three to nine months) within the same subject. This finding seems to be of clinical importance since it implicates that the effect of anticholinergic agents on the airways is predictable.

Excessive daytime sleepiness is the most common symptom in OSAS. Administering CPAP improves breathing during sleep. We evaluated the time course of the recovery of alertness following CPAP therapy in OSAS patients. Thirty-nine patients with OSAS were treated with CPAP and evaluated after one, 14, or 42 nights of treatment, 13 patients being randomly assigned to each group. All received a diagnostic polysomnogram and MSLT before treatment. The three groups had similar baseline values for nocturnal respiratory disturbance, oxygenation during sleep, fragmentation of sleep, and level of EDS. CPAP treatment was associated with a significant improvement in sleep-related respiration, oxygenation, and sleep fragmentation. The EDS showed significant improvement after one night, and further significant improvement after 14 nights, but no further significant improvement after 42 nights. The differential rate of improvement in nocturnal parameters compared with that of primary complaint of EDS suggests that OSAS patients experience a chronic functional sleep loss. As with sleep deprivation, recovery of alertness in OSAS requires several nights of normal sleep.

Ceftriaxone is a new, third-generation cephalosporin that, because of its long half-life, offers potential advantages of cost and convenience over similar agents such as cefotaxime. We compared the two drugs in a prospective, randomized study of the treatment of chest infections in seriously ill patients. Fifty-one patients (90 percent of whom were mechanically ventilated) received either ceftriaxone, 2g IV once daily, or cefotaxime, 2 g IV thrice daily, for five days. The two groups of patients appeared demographically comparable. Ceftriaxone in a single daily dose of 2 g once daily may not be satisfactory for the treatment of serious chest infections.

In a placebo controlled double-blind multicenter trial, 245 patients with bronchial asthma (131 male and 124 female patients) between 6 and 51 years of age were treated in two parallel groups. A slow-release oral formulation containing 2 mg of ketotifen or placebo was administered daily for a duration of 12 weeks. Over a period of four weeks before the study, 94 percent of the patients had asthmatic attacks. 78 percent had cough, and 62 percent had nasal symptoms. In the group treated with slow-release oral ketotifen, there were 3.9 asthmatic attacks (range, 0 to 20) per week, and in the placebo group, there were 2.9 (range, 0 to 12) (mean values during four weeks prior to start of treatment). At the end of treatment, asthmatic attacks were significantly reduced in the group treated with slow-release oral ketotifen compared with placebo. Significant reduction was also evident for cough and sputum production, as well as nasal discharge and obstruction; however, slow-release oral ketotifen did not significantly improve pulmonary function indices when compared to placebo. The use of concomitant medication (beta-sympathomimetic drugs) was also significantly reduced in the group receiving slow-release oral ketotifen. The overall efficacy assessed by the investigators was "very good" and "good" in 76 percent of the group receiving slow-release oral ketotifen and 30 percent in the group receiving placebo (p less than 0.001). Tolerability rated by the investigators was "very good" and "good" in 90 percent of the group with slow-release oral ketotifen and in 96 percent of the group with placebo (p less than 0.10). The most frequent side effects were "mild" and "moderate" sedation, sleepiness and drowsiness reported in 44 percent of the patients receiving slow-release oral ketotifen and in 26 percent of the patients receiving placebo. This difference was statistically significant (p less than 0.01).

Ventilatory data, including timing and partitioning of ventilation, were obtained from six subjects with advanced Duchenne muscular dystrophy, aged 16 to 22 years, during polysomnography on two consecutive nights; the subjects were randomized to breathing air or oxygen. Five of the six patients developed oxygen desaturation exceeding 5 percent during rapid eye movement (REM) sleep while breathing air. Minute ventilation on air (the mean of at least six consecutive minutes) was 6.9 +/- 0.7 (SEM) L min-1 but fell, owing to decreases in both tidal volume and frequency, to 4.9 +/- 0.3 L min-1 (p less than 0.05) in slow wave sleep and to 4.5 +/- 0.6 L min-1 (p less than 0.05) in REM sleep. Similar falls were seen on oxygen. The variability of all ventilatory data was significantly greater in REM than non-REM (NREM) sleep. The mean abdominal contribution to breathing was lower than predicted for wakefulness and all sleep stages, and two subjects showed paradoxical abdominal movement in NREM sleep; a correlation (p less than 0.05) existed between the NREM abdominal (diaphragmatic) contribution and the extent of oxygen desaturation subsequently seen in REM. We conclude that although awake minute ventilation is normal in Duchenne muscular dystrophy, hypoventilation occurs in all sleep stages, and those with diaphragmatic dysfunction are especially vulnerable to oxygen desaturation during REM sleep.

We have investigated whether oral theophylline potentiated the cardiovascular effects of fenoterol administered by metered-dose inhaler. Eight healthy subjects were investigated on four occasions. On successive days (1 and 2), the subjects were given doses of 400 micrograms, 600 micrograms, and 800 micrograms of fenoterol at 15-minute intervals (total dose, 1.8 mg) or matched placebo. Systolic time intervals, blood pressure, and the ECG were recorded at baseline and five minutes after each inhalation. Thereafter, the subjects were treated with slow-release theophylline for eight days. On days 9 and 10, the procedures on days 1 and 2 were repeated. The order of treatment was applied according to a crossover Latin-square design. The effects after theophylline alone were no different from placebo. Theophylline potentiated those hemodynamic effects of fenoterol due to enhanced cardiac sympathetic tone (mean +/- SE) as measured by a decrease in Q-S2I (-41.6 +/- 7.6 ms vs -27.3 +/- 5.9 ms; p = 0.0004), an increase in systolic BP (23.5 +/- 2.8 mm Hg vs 9.0 +/- 5.3 mm Hg; p = 0.00001), and an increase in heart rate (15.8 +/- 1.6 bpm vs 9.1 +/- 3.7 bpm; p = 0.0013). The responses mediated by beta 2-adrenergic receptor stimulation, namely, a decrease in PEP and diastolic BP, were not potentiated. Although fenoterol prolonged the Q-Tc interval and decreased T-wave amplitude, these effects were not potentiated by theophylline. Oral theophylline potentiates the positively inotropic and chronotropic effects of fenoterol.

This double-blind crossover study compared the efficacy of two methods of delivery (MDI-spacer and nebulizer) of inhaled albuterol to patients hospitalized for an acute exacerbation of COPD. Within 24 h of admission, 20 subjects (mean age, 69 years) with severe airflow obstruction (mean FEV, 0.69 L) were subjected to a treatment with an MDI-spacer (0.36 mg of albuterol or placebo) followed by treatment with a nebulizer (2.5 mg of albuterol or placebo). Active drug was given by only one device (randomly assigned in a double-blind manner), and the entire sequence was repeated in 4 h, with active drug given in the alternate device. Spirometric data and the Borg dyspnea score were obtained before and 1 h after each sequence of treatments. Treatment resulted in significant improvements in the FEV1, FVC, and Borg score. The percent improvement in the FEV1 was slightly larger after treatment with the nebulizer (16.7 percent vs 13.4 percent). Improvements in the Borg score were slightly larger after treatment with the MDI-spacer (-1.08 vs -0.73). However, these differences were not statistically significant. This study suggests that the MDI-spacer system is an effective method of sympathomimetic delivery in this setting, provided patients are able to master the technique.

Eighteen patients (nine asthmatic patients and nine with poorly reversible airflow obstruction) with stable, severe chronic airflow obstruction, completed a four-week randomized, doubled-blind, placebo-control, crossover trial comparing the acute and chronic effects of terbutaline administered by metered-dose inhaler (MDI) and nebulizer (NEB). Equipotent doses of terbutaline were selected from the comparison of separate cumulative dose-response curves for MDI and NEB. The MDI and NEB given acutely produced similar bronchodilatation and improvement in exercise performance. Spirometric indices, 6 min walking distance, symptom scores and extra beta-agonist use were no different between MDI and NEB treatment fortnights in the outpatient study. We conclude that the degree of bronchodilatation achieved in these patients is a reflection of the dose of bronchodilator administered and not the mode of administration. There is no justification for the preferred outpatient use of nebulized bronchodilators in patients with stable chronic airflow obstruction who can use adequate doses of bronchodilators via a metered-dose inhaler.

We investigated the hypothesis that prior airway muscarinic receptor stimulation (with aerosolized methacholine) would modify the bronchoconstrictor response to histamine, which is, in part, vagally mediated. On four different experiment days, the following combinations of methacholine and histamine inhalation challenges were performed in 15 subjects (nine normal and six asthmatic) in a random fashion: methacholine-histamine, histamine-methacholine; methacholine-methacholine and histamine-histamine. Cumulative provocative dose of each agonist which caused a 50 percent decrease in SGaw was estimated (PD50). The second challenge was performed approximately 1 hour after the first challenge, when SGaw had returned to baseline. In normal subjects, prior muscarinic stimulation with methacholine suppressed the subsequent bronchoconstrictor response to histamine (mean +/- SE PD50 histamine increased from 13.7 +/- 3.1 to 28.4 +/- 7.2 breath units), without modifying the bronchoconstrictor response to methacholine. In asthmatic subjects, prior methacholine exposure failed to modify the bronchoconstrictor responses to histamine and methacholine. In contrast, prior challenge with histamine did not modify the subsequent bronchoconstrictor responses to histamine and methacholine in both normal and asthmatic subjects. Pretreatment with ipratropium bromide attenuated the histamine-induced bronchoconstriction, suggesting that airway effects of histamine, in part, are vagally mediated. These data suggest that prior muscarinic stimulation has a protective effect on histamine-induced bronchoconstriction in normal subjects and the absence of this inhibitory effect in asthmatic patients may represent loss of a protective muscarinic receptor mechanism.