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Biomedical subjects

S Kesten

Publications and source records attributed to S Kesten.

At least 91 records · Page 5Linked to original sources
PubMed1993

Evaluation of fluticasone propionate (500 micrograms day-1) administered either as dry powder via a Diskhaler inhaler or pressurized inhaler and compared with beclomethasone dipropionate (1000 micrograms day-1) administered by pressurized inhaler.

Five hundred and eighty-five patients with moderate asthma, currently receiving 400-1000 micrograms day-1 of an inhaled corticosteroid, were treated for 6 weeks in a double-blind, randomized, parallel group study with either 500 micrograms day-1 fluticasone propionate as a dry powder via a Diskhaler inhaler, 500 micrograms day-1 fluticasone propionate via a pressurized inhaler or 1000 micrograms day-1 beclomethasone dipropionate via a pressurized inhaler. For all three treatment groups, mean morning and evening peak expiratory flow rates (PEFRs) increased within 1 week of the start of treatment. There were also improvements in clinic lung function, daytime and night-time asthma symptoms and a reduction in daytime and night-time rescue bronchodilator medication in all three groups. There were no statistically significant differences between the two formulations of fluticasone propionate in any of the efficacy parameters. Fluticasone propionate via the Diskhaler was significantly more effective than beclomethasone dipropionate over the 6 week study period in reducing diurnal variation (mean difference--4 l min-1, 95% CI--8 to 0 l min-1: P = 0.03). Fluticasone propionate via the Diskhaler produced a statistically significant improvement in night-time symptoms when compared to beclomethasone dipropionate whereas, beclomethasone dipropionate 1000 micrograms day-1 was statistically significantly more effective than both formulations of fluticasone propionate in improving daytime symptoms (P < 0.05). However, these statistical differences must be viewed together with the fact that very few patients recorded a score of 2 or more for both daytime or night-time symptoms. There was a similarly low incidence of adverse events with all three treatments with no evidence of hypothalamic pituitary adrenal (HPA)-axis suppression. The results of the 6-week comparative study showed that 500 micrograms day-1 fluticasone propionate whether administered via pressurized inhaler or Diskhaler is as effective and as safe as 1000 micrograms day-1 beclomethasone dipropionate administered via a pressurized inhaler in the treatment of moderate asthma. Over 12 months fluticasone propionate 500 micrograms day-1 via a pressurized inhaler was at least as effective and as well tolerated as beclomethasone dipropionate 1000 micrograms day-1.

Adolescent↗
PubMed1993

Miliary pulmonary cryptococcosis in a patient with the acquired immunodeficiency syndrome.

A 33 year old man with AIDS presented with fever, dyspnoea, cough and a miliary pattern on the chest radiograph. Cryptococcus neoformans infection was diagnosed from bronchoalveolar lavage bronchoscopy. This case supports the principle that, in patients with AIDS, pulmonary infections can exhibit variable radiographic features and that definitive diagnosis should always be considered.

AIDS-Related Opportunistic Infections↗
PubMed1993

A retrospective comparative study of in-hospital management of acute severe asthma: 1984 vs 1989.

Recent controversies examining the management of acute asthma prompted us to investigate whether there had been any significant changes in our management practices. We therefore audited the charts of all patients admitted to a large tertiary-care university-affiliated hospital with a primary diagnosis of acute asthma during the years of 1984 and 1989. A total of 67 patients' charts were reviewed (39 in 1984 and 28 in 1989). The mean age and initial flow rates (FEV1 or peak expiratory flow rate [PEFR]) were similar. In the emergency room, chest radiographs and arterial blood gas analyses were done more frequently than objective measures of flow. Fifty-one percent (20/39) of the patients had no measurement of flow in the emergency room in 1984 and 39 percent (11/28) in 1989 (p > 0.05). In both years, approximately 20 percent of the patients had no record of flow rates during their hospitalization (21 percent [8/39] in 1984 and 18 percent [5/28] in 1989). More studies of the blood were ordered in 1989, including hepatic enzyme and electrolyte measurements for no clear reasons. The clinical utility of chest radiographs was negligible. While the vast majority of patients received systemic corticosteroids in both years (85 percent [33/39] in 1984 and 96 percent [27/28] in 1989), 23 percent (9/39) and 18 percent (5/28) were discharged without oral steroid therapy in 1984 and 1989, respectively (p > 0.05). There was a significant decline in the use of aminophylline (95 percent [37/39] to 54 percent [15/28]; p < 0.05) and an increase in the use of ipratropium bromide (15 percent [6/39] to 75 percent [21/28]; p < 0.05) in 1989. Theophylline levels were less likely to be measured in 1989, and the majority of levels in both years were either subtherapeutic or toxic. No patients were discharged with peak flow meters or recorded action plans, although follow-up arrangements were recorded in 87 percent (34/39) and 96 percent (27/28) of the patients in 1984 and 1989. We conclude that while improvements in in-hospital management of asthma were noted in 1989, suboptimal management practices are still common.

Acute Disease↗
PubMed1993

Prospective assessment of a standardized pathologic grading system for acute rejection in lung transplantation.

Using the recent standardization of the pathologic definitions for acute lung rejection, we prospectively evaluated 66 consecutive bronchoalveolar lavage (BAL) and transbronchial biopsy (TBB) specimens in 32 patients after lung transplantation. Clinical indications for bronchoscopies were surveillance (n = 44), rejection (n = 18), and infection (n = 4). Bronchoalveolar lavages were obtained from the right middle lobe or lingula in single lung transplant and from both sites in double lung transplant recipients. Cytosmears for differential cell counts were performed and 400 to 500 cells were counted. Five to eight TBB specimens were taken from two different lobes and stained with hematoxylin-eosin, elastic trichrome, and silver methenamine. Sixty-four of 66 sets of biopsy specimens were satisfactory, but 3 were eliminated because of presence of cytomegalovirus cytopathic changes. Of the remaining 61, rejection was presented in 45 (74 percent): grade 1 in 23 (38 percent), grade 2 in 19 (31 percent), and grade 3 in 3 (5 percent). In 30 of 42 (71 percent) surveillance biopsy specimens, rejection was present, grade 1 in 18 (43 percent) and grade 2 or 3 in 12 (28 percent). In TBBs performed for clinical suspicion of rejection, 15 of 18 TBB specimens (83 percent) showed rejection, grade 1 in 5 (28 percent) and grade 2 or 3 in 10 (55 percent). Of four biopsies performed for suspicion of infection, one was normal and three showed rejection in addition to infection. These three were eliminated from further analysis due to the limitation of the Lung Rejection Study Group criteria in distinguishing rejection from infection. Of the 45 episodes of rejection, 24 (53 percent) occurred during the first 3 months posttransplantation, 8 (18 percent) between 3 and 6 months and 13 (29 percent) after 6 months. Percentage of BAL lymphocytosis was significantly elevated in grade 2 or 3 rejection (28 +/- 4) when compared with grade 1 (15 +/- 3) or grade 0 (10 +/- 3) (p < 0.001). Bronchoalveolar lavage lymphocytosis also correlated with severity of rejection (r = 0.6). We conclude that according to the standardized criteria of the Lung Rejection Study Group, acute lung rejection occurs more frequently than clinically suspected early and late after transplantation and that BAL lymphocytosis correlates with the presence and severity of histologically proven rejection.

Acute Disease↗
PubMed1993

Physician perceptions and management of COPD.

To assess awareness and understanding of obstructive airway diseases by primary-care physicians, the authors surveyed a randomly selected population of 75 primary care practitioners. During one-on-one interviews, physicians were presented with a standardized case scenario and a subsequent series of open-ended questions concerning asthma and COPD. Each respondent was presented in randomized fashion with one of two versions of a case description of a hypothetical 52-year-old male smoker with a recent upper respiratory tract infection and persistent productive cough. The only difference between case descriptions was that one included explicit reference to an earlier tentative diagnosis of chronic bronchitis (CB version); the other description made no specific mention of this diagnostic term (NCB version). Chest radiographs were requested by 80 percent of physicians and sputum cultures by 50 percent, these percentages not differing significantly between CB and NCB groups. Spirometry was requested less often than either of the foregoing tests (21 percent). The CB group requested spirometry significantly more often than the NCB group (38 percent vs 5 percent, p < 0.05). The most frequently mentioned primary diagnosis was bronchitis/pneumonia (33 percent), followed by bronchitis (28 percent) and chronic bronchitis (16 percent), all of which were similar in both groups. However, the diagnostic term "COPD" was the primary diagnosis in 16 percent of the CB group, compared with 8 percent in the NCB group (p > 0.05). Oral antibiotics were the most frequently chosen first-line drug therapy (63 percent). In subsequent questions concerning the management of obstructive airway diseases, primary practitioners distinguished COPD from asthma conceptually, but their prescribed therapy for the two disorders was less distinct. beta 2-agonists were selected most frequently and similarly as initial therapy for both disorders (53 percent). Minor differences between first-line therapeutic choices included nonsignificant trends toward the more frequent mention of anticholinergic bronchodilators for COPD than for asthma (10 percent vs 0 percent) and the more frequent selection of inhaled corticosteroids for asthma (12 percent vs 5 percent). The authors conclude that to the extent that questionnaire responses reflect actual practice, primary care practitioners (1) have a low index of suspicion for obstructive airway disease, (2) markedly underutilized spirometry as a screening tool, (3) consider beta 2-agonists first-line therapy for COPD and asthma, and (4) despite considering COPD and asthma different disease processes, choose similar medications for each disorder.

Airway Obstruction↗
PubMed1993

Pharmacist knowledge and ability to use inhaled medication delivery systems.

Previous studies have shown that a significant proportion of patients and physicians have difficulty using metered dose inhaler (MDI) delivery systems. It has been suggested that paramedical personnel such as pharmacists could address this problem by serving as patient educators. Few studies have assessed a pharmacist's knowledge of and ability to use inhaled devices, including not only the conventional MDI but newer devices such as an add-on spacing chamber (Aerochamber) and a multidose dry powder inhaler (Turbuhaler). We therefore approached all pharmacists in a predefined geographic area of a large city in order to evaluate their knowledge of and ability to use inhaled medications. Of 62 pharmacists approached, 45 (73 percent) agreed to participate. Ability to use the conventional MDI, Aerochamber (A), and Turbuhaler (T) was graded by a trained observer using a checklist of 11 essential steps. The percentage of pharmacists performing greater than 6, 8, and 10 steps correctly for each device was MDI = 96 percent, 87 percent, 62 percent; MDI + A = 80 percent, 76 percent, 47 percent; T = 67 percent, 64 percent, 29 percent. The most common problems with the MDI were forgetting to shake prior to use and coordinating inspiration with actuation. The most common problems with the MDI + A were forgetting to shake prior to use, remembering to inspire after actuation, and breath holding after inspiration. The most common difficulty with the T was total unfamiliarity with the device with 33 percent of pharmacists achieving less than 2 steps correctly. The observer subsequently administered a questionnaire of 11 clinically relevant questions for each of the devices tested. The mean score was 50 percent with only 21 percent of pharmacists scoring above 70 percent. Thirty-three percent of respondents had no instruction in device use beyond reading the packing insert; 40 percent had received instruction from a pharmaceutical representative; only 24 percent had received instructions from professional school. We conclude that a pharmacist's knowledge of inhaling devices is roughly proportional to the length of time the device has been available and that pharmacists form another group of health care professionals who require further teaching regarding inhaled medication delivery systems.

Asthma↗
PubMed1993

Cavitary aspergillosis as a complication of AIDS.

The authors report the radiographic findings in two patients with the human immunodeficiency virus (HIV) who presented with cavitary lung disease caused by Aspergillus. Recognition of the disease in one of the patients led to successful medical therapy. Disease due to Aspergillus must be considered in HIV-positive patients with cystic or cavitary disease appearing in chest radiographs.

AIDS-Related Opportunistic Infections↗
PubMed1992

Physiologic and nonphysiologic determinants of aerobic fitness in mild to moderate asthma.

We studied 27 patients (seven male, 20 female) with stable mild-to-moderate asthma to measure their level of physical fitness and to determine if a relationship existed between aerobic fitness and the degree of airway reactivity, expiratory flow rates, or the amount of habitual leisure-time physical activity. Nonspecific bronchial hyperreactivity (NSBHR) was quantified by methacholine inhalation challenge. On a separate day, exercise capacity was evaluated with incremental exercise testing to exhaustion after bronchodilator pretreatment. The level of physical activity was assessed with a validated written questionnaire. FEV, was 78 +/- 13% predicted prebronchodilator and 92 +/- 14% predicted postbronchodilator. The mean provoking concentration of methacholine that caused a 20% decrease in FEV1 (PC20) was 1.14 +/- 1.38 mg/ml and ranged from 0.019 to 5.71 mg/ml. There was no correlation between PC20 and prebronchodilator FEV1 r = 0.37, p greater than 0.05). Mean maximal oxygen uptake (VO2max) was not significantly different from predicted normal values (36.9 +/- 10.8 versus 38.5 +/- 5.3, p = 0.32). Mean maximal O2pulse (maximal heart rate/VO2max), anaerobic threshold, and dyspnea index were within normal limits. There was no relationship between VO2max and FEV1 when expressed as percentages of predicted values (r = 0.08, p = 0.71) or between VO2max and PC20 (r = 0.23, p = 0.25). There was, however, a significant relationship between VO2max and the level of habitual leisure-time activity (F = 3.64, p less than 0.05). Results from the exercise questionnaire suggested that asthmatics perceive their disease as a limiting factor to improved aerobic fitness and that they lack adequate knowledge about asthma and exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Sustained improvement in asthma with long-term use of formoterol fumarate.

Inhaled formoterol fumarate, a long acting beta 2 agonist, produces bronchodilatation that is sustained for approximately 12 hours. To determine whether such bronchodilator effects are maintained and asthma control sustained during chronic administration, we monitored airflow indices and clinical control in 112 asthmatic patients who self administered formoterol twice daily for periods ranging from 9 to 12 months. Subjects were recruited immediately following completion of a 3-month double-blind comparison of formoterol, 12 micrograms, bid versus salbutamol, 200 micrograms, qid. Assessments were conducted at baseline, 3, 6, and 9 months, where baseline represents the final visit of the 3-month comparative study. Patients were asked to complete diary cards and twice daily PEFR for a 2-week period before each assessment. Throughout the follow-up study, there was no indication of worsening of asthma control or deteriorating lung function. For the patients who continued to receive formoterol, the previous improvement in asthma control and lung function was maintained at the level reached in the 3-month study. There was an improvement in flow rates and asthma symptoms in the group switched from salbutamol to formoterol by the first clinic visit. This improvement in asthma control and lung function was maintained over the subsequent 6 months. Formoterol was well tolerated during the study period. We conclude that prolonged use of formoterol fumarate twice daily results in sustained improvement in symptoms and flow rates in asthma with no evidence of tachyphylaxis.

Adolescent↗
PubMed1991

A three-month comparison of twice daily inhaled formoterol versus four times daily inhaled albuterol in the management of stable asthma.

We compared the efficacy of inhaled formoterol, a long-acting beta 2-agonist, with inhaled albuterol in 145 stable adult asthmatics in a 12-wk multicenter trial. Patients were allocated in randomized double-blind fashion to maintenance therapy with either formoterol 12 micrograms twice a day or albuterol 200 micrograms four times a day in addition to their other asthma medications. Patients were allowed to use "rescue" 100-micrograms albuterol puffs on an as-needed basis. Mean baseline FEV, in the morning before bronchodilator was 2.14 +/- 0.76 L and 1.98 +/- 0.71 L for the formoterol and albuterol groups, respectively, these values being used as baseline covariates in subsequent analysis of predrug and postdrug FEV1. Measured at each clinic visit, morning predrug FEV1 rose significantly with formoterol treatment and was significantly greater at all visits than in the albuterol group, the greatest difference being in Week 8 (2.40 +/- 0.77 versus 1.92 +/- 0.66 L, p less than 0.001). Morning FEV1 30 min postdrug was significantly higher in the formoterol group at Weeks 2 and 8, the trend not reaching statistical significance at other times. Diurnal variation in prebronchodilator peak flow rates was significantly reduced in the formoterol group throughout the trial (17 versus 42 L/min at Week 12, p less than 0.0001). The number of asthma episodes per week was significantly less in the formoterol group during Weeks 4, 8, and 12 as were the number of sleep disruptions during Weeks 2, 4, 6, 8, and 12. Significantly more rescue albuterol was required in the albuterol group by Week 2 and throughout the remainder of the study.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Inhalation↗
PubMed1991

Impaired exercise capacity in adults with moderate scoliosis.

We measured lung function and exercise tolerance in 15 adults with moderate kyphoscoliosis (thoracic curvatures between 25 degrees and 70 degrees, mean +/- SD = 46.93 degrees +/- 14.02 degrees). Forced vital capacity showed a slight reduction from values predicted from age and sex matched control subjects (3.39 +/- 1.06 vs 4.06 +/- 0.82 L, p less than 0.05). However, exercise tolerance was significantly lower than previously reported in healthy adults (VO2max = 31.60 +/- 9.12 vs 37.07 +/- 4.91 ml/kg/min, p less than 0.05). Despite the reduced exercise tolerance, the ratio of maximum tidal volume to vital capacity (VTmax/VC) was similar to that observed in healthy adults. The mean dyspnea index (VEmax/MVV) was also normal at 69.4 +/- 19.0. Hypoxic and hypercapnic ventilatory responses were within predicted normal limits at 0.67 +/- 0.37 L/min-1 fall in SaO2-1 and 1.67 +/- 0.92 L/min-1 mm Hg PCO2(-1). We conclude that the impairment of exercise performance found in adults with moderate scoliosis cannot be attributed to any important ventilatory limitation, abnormality in lung volume, or impaired chemoreceptor sensitivity. We suggest that the reduced VO2max likely arises from deconditioning and lack of regular aerobic exercise.

Adult↗
PubMed1991

Response characteristics of a dual transcutaneous oxygen/carbon dioxide monitoring system.

We tested the response characteristics of a dual transcutaneous (tc) PO2/PCO2 monitoring system in healthy subjects who breathed various gas mixtures, and we compared steady-state tc readings to simultaneous arterial blood gas analysis in 20 stable respiratory outpatients. The electrodes were simple to apply, required very little skin preparation, and had trivial signal drift. In healthy subjects, tcPCO2 lag time during CO2 rebreathing was 16.8 seconds, with a 90 percent response time of 77.9 seconds after CO2 breathing was discontinued. The 90 percent response times of the O2 electrode when subjects breathed a hypoxic mixture was 257 seconds after a lag of 31 seconds. When inhaled gas mixtures were changed from hypoxia to room air, the lag time was shorter (12.5 seconds), but 90 percent response time exceeded 5 minutes. In stable patients with respiratory disease, tcPCO2 and tcPO2 were linearly related to PaCO2 (range, 19 to 53 mm Hg) and PaO2 (range, 45 to 99 mm Hg), respectively (tcPCO2 = 1.4 PaCO2-9.44, with r = 0.90 and SEE = 5.35 mm Hg; tcPO2 = 0.56 PaO2 + 20.4, with r = 0.53 and SEE = 11.7 mm Hg). We conclude that the response of the dual transcutaneous monitoring system is more rapid for the CO2 than the O2 electrode and may be rapid enough to be useful in some clinical settings; however, the O2 system fails to offer the response characteristics and accuracy that would allow it to be substituted for arterial gas tensions in unstable clinical situations.

Blood Gas Monitoring, Transcutaneous↗
PubMed1991

Asthma in New Zealand: implications for North America.

In the early 1980s, reports of a significant rise in asthma mortality emanated from New Zealand. Difficulties in accessing medical care, noncompliance with medication, inadequate medical management, lack of patient education, and inadequate recognition of asthma severity have been suggested as factors that may have contributed to the excess of asthma mortality. Asthma mortality has now declined significantly in New Zealand. We traveled to New Zealand to examine why the incidence of asthma deaths declined in that country at the time where it may have continued to rise in North America. We hypothesize that increased patient and physician education, targeting of high-risk socioeconomic groups, and increased public awareness have played a large role in these improved statistics. The measures taken in New Zealand which have involved a cooperative approach between lay organizations, the pharmaceutical industry, government agencies, and medical personnel may be adapted to North America with, it is hoped, similar results.

Ambulatory Care↗
PubMed1990

A 3-month evaluation of the efficacy of nedocromil sodium in asthma: a randomized, double-blind, placebo-controlled trial of nedocromil sodium conducted by a Canadian multicenter study group.

Nedocromil sodium is a pyranoquinoline dicarboxylic acid derivative, formulated in a metered-dose inhaler. Because nedocromil sodium has in vitro and in vivo anti-inflammatory properties, it was evaluated in a group of steroid-dependent patients with asthma to observe how well it might be tolerated and for evidence of any beneficial effects. In a double-blind, group-comparative study, 127 patients received nedocromil sodium and 61 received placebo, administered as two puffs of 2 mg, four times per day, for 12 weeks. Ten patients developed adverse reactions, seven receiving active drug and three patients receiving placebo. Two patients of each group withdrew because of worsening asthma. Despite selecting patients whose asthma was stable, when they were receiving established therapeutic regimens that included steroids and bronchodilators, it was found that diary-card symptom scores, morning and evening peak expiratory flow rate values, and inhaled beta-agonist usage all demonstrated slight but significant benefit with addition of nedocromil sodium. It is concluded that the inhaled, anti-inflammatory agent, nedocromil sodium, may be added to asthma-treatment regimens with the reasonable expectation of further modest symptomatic benefit.

Adult↗
PubMed1990

Pulmonary disease following intravesical BCG treatment.

Bacillus Calmette-Guérin (BCG) is an attenuated strain of Mycobacterium bovis that has been used in the treatment of malignant disease for over 20 years and for the treatment of bladder cancer since 1976. Major complications of this treatment are infrequent. We report two cases of systemic illness with pulmonary manifestations after treatment with intravesical BCG.

Administration, Intravesical↗
PubMed1990

Respiratory rate during acute asthma.

Asthmatic patients hyperventilate during acute attacks, but controversy persists as to whether they breathe rapidly, deeply or both. We monitored respiratory rate under the three following conditions: (1) asthma treated in the emergency room; (2) airways obstruction provoked by methacholine inhalation; and (3) airways obstruction provoked by exercise. In 47 acutely ill asthmatic patients, respiratory rate was higher than in 42 nonasthmatic control patients in the emergency room. Pretreatment respiratory rate correlated with peak expiratory flow rate and forced expired volume in one second. In 17 asthmatic patients and 16 healthy volunteers, breathing pattern was monitored by respiratory inductance plethysmography. Methacholine inhalation and exercise provoked significant airways obstruction in asthmatic patients but not in control subjects. In asthmatic patients, minute ventilation and tidal volume increased above that of control subjects following methacholine and exercise, but the rate was no higher than in control subjects. We conclude that the respiratory rate is increased in naturally occurring asthma, but not when acute airways obstruction is induced transiently in the laboratory. In the former setting, the respiratory rate is correlated with spirometric measures of airflow obstruction, but the weakness of the correlation does not allow the respiratory rate to be used as a substitute for spirometry.

Acute Disease↗
PubMed1990

Ventilatory effects of nasal continuous positive airway pressure.

Nasal continuous positive airway pressure (nCPAP) improved arterial oxygenation in patients with sleep apnoea as well as those with acute pulmonary processes such as Pneumocystis carinii pneumonia. Despite an expanding pool of clinical information, little if any attempt seems to have been made to see whether nCPAP alters ventilatory patterns. The effect of nCPAP was assessed by respiratory inductance plethysmography in 14 healthy males. nCPAP reduced respiratory rate (14.3 +/- 1.47 to 9.7 +/- 1.98, p less than 0.0001) but increased tidal volume (0.483 +/- 0.090 to 0.602 +/- 0.140 l, p = 0.01). Accordingly, minute ventilation decreased (6.91 +/- 1.20 to 5.64 +/- 0.93 l.min-1, p = 0.0002). Duty cycle (TI/TTOT) decreased from 0.43 +/- 0.04 to 0.35 +/- 0.05 s during nCPAP (p less than 0.0001). Mean inspiratory time and mean expiratory time increased with nCPAP (1.79 +/- 0.19 to 2.20 +/- 0.41 and 2.44 +/- 0.38 to 4.27 +/- 1.07 s, respectively, p less than 0.02), but there were no significant changes in mean inspiratory flow rate or partitioning of rib cage and abdominal/diaphragmatic contributions to tidal volume. We conclude that nCPAP effects ventilatory pattern in a manner similar to that described for expiratory threshold loading; that is, by decreasing respiratory frequency and minute ventilation. nCPAP does not appear to stimulate healthy subjects to increase their level of ventilation.

Adult↗