Inhalation Technique In Patients Research Articles

Pharmacist‐led intervention study to improve inhalation technique in asthma and COPD patients

RATIONAL AND AIMS: Inhaled therapy is the mainstay of treatment in patients with asthma and chronic obstructive pulmonary disease (COPD). For effectiveness of pharmacotherapy, correct use of medication is required. The aims of this study were to survey the quality of inhalation technique in patients and to determine the effect of a single intervention in community pharmacies by means of standardized procedures. A total of 757 patients with asthma or COPD were randomly selected by 55 community pharmacies. At baseline, patients were interviewed and their inhalation technique was assessed with a 21-items checklist. Any error was recorded and, if necessary, patients were instructed in the proper use of their device. After 4-6 weeks, demonstration of inhalation technique was repeated in the community pharmacies and a pre-post comparison was performed. A total of 597 patients (78.9%) made at least one mistake in performing the inhalation technique at baseline. This number dropped to 214 (28.3%) from the first to the second appointment. All patients did benefit from the pharmacists' intervention regardless of their former training experiences. Inhalation technique of asthma and COPD patients is poor. In daily practice, community pharmacy-based pharmacists are well suited to significantly supplement doctor-based education in inhalation technique.

Sustaining delivery of the first publicly reimbursed cognitive service in Denmark: a cross-case analysis

The aim was to identify local organisational factors that affect sustained delivery of the first Danish publicly reimbursed cognitive service, the Inhaler Technique Assessment Service (ITAS). The ITAS is a 10-min interactive counselling session during which pharmacy staff assess the inhalation technique of individual asthma patients at the pharmacy counter, and correct any errors. Knowledge of how the organisation of a local pharmacy influences ITAS provision will be used to develop quality indicators as part of a targeted quality-assurance system to support the sustainability of the service in all Danish community pharmacies. Qualitative methods included field observations, semi-structured interviews, group interviews and the collecting of documentary material. Data-source and method triangulation were applied. Seven pharmacies were included in the study. A cross-case analysis compared pharmacies with sustained and reduced numbers of services based on three selected themes: administration of the ITAS, leadership interventions and professional values of pharmacy owner and staff. Pharmacies with sustained delivery had introduced systematic evaluations of the local delivery of the ITAS and made ongoing efforts to improve staff competencies. They dealt with individual barriers such as lack of knowledge of rarely distributed inhalation devices and communication techniques. Pharmacy staff in general rarely assessed patients' clinical needs before offering the service and rarely provided follow-up. Thus, pharmacy staff failed to utilise the full clinical potential of the ITAS. In order to achieve and support further ITAS sustainability, the knowledge, skills and professional values of pharmacy staff must be developed. Human resource leadership techniques would be useful in achieving this aim, as would focusing on the service by providing systematic evaluations.

COPD Management in Primary Care: An Observational, Community Pharmacy–Based Study

Chronic obstructive pulmonary disease (COPD) is a prevalent disease that is frequently treated in primary care. However, data regarding the primary care management of COPD are scarce. Such observational data are necessary to detect problem areas and to develop targeted interventions for improvement of COPD management. To provide a detailed description of (1) drug therapy, (2) drug adherence, (3) inhalation technique, and (4) health status of patients with COPD recruited via community pharmacies. A cross-sectional, observational study was conducted in 93 pharmacies in Belgium. Participants (N = 555) completed a questionnaire collecting information on personal characteristics, smoking history, influenza vaccination, COPD medication, and adverse effects. Adherence to COPD maintenance medication was analyzed 1 year retrospectively through prescription refill rates. Inhalation technique was scored using a checklist. Health status was evaluated with the St. George's Respiratory Questionnaire, the Clinical COPD Questionnaire, and the Modified Medical Research Council dyspnea scale. The mean age of the patients was 68.6 years; 73.7% were men and 37.2% were current smokers. The influenza vaccination status was significantly lower in patients aged less than 65 years (65.7%) than in patients aged 65 years or more (86.2%) (p < 0.001). Fixed combinations of inhaled corticosteroids and long-acting beta(2)-agonists were the most frequently used COPD medications (75.4%). About 48% of patients were underadherent (<80% adherence), 47% were adherent (80-120% adherence) and 5% were overadherent (>120% adherence). Predictors for underadherence were age and number of drugs. Twenty-one percent of patients made major inhalation technique errors with rescue medication; these were all errors in handling pressurized metered-dose inhalers (pMDIs). This observational study on COPD management in primary care highlights 4 main aspects that could be improved: (1) drug adherence, (2) inhalation technique with pMDIs, (3) influenza vaccination in COPD patients younger than 65 years, and (4) smoking cessation.

Inappropriate Techniques Used by Internal Medicine Residents with Three Kinds of Inhalers (a Metered Dose Inhaler, Diskus, and Turbuhaler): Changes after a Single Teaching Session

Background. While initial education and regular evaluation of inhaler technique in patients are emphasized in the management of asthma and chronic obstructive pulmonary disease, health care professionals are not experienced in using inhalers. This study assessed whether internal medicine residents used common inhalers correctly and whether a single teaching session successfully improved their performance. Methods. We evaluated 142 internal medicine residents from six university hospitals in Korea for their techniques with three different inhaler devices: a metered dose inhaler (MDI), Diskus, and Turbuhaler. We assessed whether participants completed each step in using the three inhalers and classified overall performance as good, adequate, or inadequate for each inhaler type. To estimate the effect of a single teaching session, reassessment was performed 2 months after education. Results. Performance grade was inadequate for 50.7% of participants with a MDI, 43.0% for Diskus, and 51.4% for Turbuhaler. An early year of residency was associated significantly with inappropriate technique for Diskus (p = 0.003), but not for MDI and Turbuhaler. After a single teaching session, overall skills improved significantly for all three inhalers. The proportion of subjects with good or adequate skill changed notably from 39.7% to 83.8% for MDI (p = 0.001), from 50.0% to 86.8% for Diskus (p = 0.001), and from 44.1% to 88.2% for Turbuhaler (p = 0.001). Conclusions. These findings demonstrate that a high proportion of internal medicine residents cannot use inhalers correctly and just a single teaching can effectively enhance their inhaler technique.

The ADMIT series — Issues in Inhalation Therapy. 4) How to choose inhaler devices for the treatment of COPD

For patients with COPD, inhalation is the preferred route of administration of respiratory drugs for both maintenance and acute treatment. Numerous inhaler types and devices have been developed, each with their own particularities, advantages and disadvantages. Nevertheless, published COPD management guidelines pay little attention to the optimal choice of inhaler devices for COPD patients. Although efficacy and safety are the primary factors determining the choice of an inhaler device, randomised controlled trials (RCTs) directly comparing the efficacy and safety of different inhalers in COPD patients are scarce. Systematic reviews on this subject failed to find significant differences between devices for any of the clinical outcomes studied. When selecting a device for the delivery of inhaled drugs in 'real life' patients with COPD, other factors should be considered. These include availability and affordability of the inhaled drugs and inhaler devices, the uniformity of inhaler devices when several drugs are to be inhaled, the ability of patients to handle correctly the selected device - in particular taking into account the advanced age of the average COPD patient, and finally the patient's preference. The prescribing clinician's task is to provide comprehensive instructions for correct handling of the device and to review regularly the patient's inhalation technique.

Assessment of Inhaler Technique in Patients Attending a Chest Hospital in Riyadh City

Assessment of Inhaler Technique in Patients Attending a Chest Hospital in Riyadh City

Educational Practice for Inhaled Treatments in French Cystic Fibrosis Care Centers

Inhaled treatments are very common in cystic fibrosis (CF) patients. We sent a questionnaire to the 49 French Cystic Fibrosis Care Centers (CFCCs) to see how the inhalation technique of CF patients was initiated and monitored (composition and formation of a potential educational team, use of a manual for use, amount of devices available for demonstration, education to disinfection procedure, realization and frequency of the inhalation technique monitoring, use of the patient's own device, and frequency of checking when a pediatric patient transfers to an adult CFCC). Results were expressed in percent and compared with the test of the difference between two correlated proportions. Education for aerosol therapy was not performed in about 20% of the CFCCs. A specific educational member was present in 33 CFCCs (68%). CFCCs owned statistically less nebulizers for demonstration than other devices. Disinfection advices were always given for nebulizers, but less frequently for spacers (80%) and dry powder inhalers (50%). The inhalation technique was monitored less than once a year or never in 22% of the cases, and rarely with the patient's own material. This monitoring was device dependent (56% with nebulizers vs. 76% with the other devices, p < 0.05). For nebulizers, monitoring depended on the presence of an educational member (p < 0.01) and of a manual for use (p = 0.03). When transferring to an adult CFCC, the inhalation technique was checked in less than a third of the patients. The inhalation technique is poorly and insufficiently initiated and monitored in CF patients. Educational teams and programs are urgently required.

The Coulee Region Community Pharmacy Asthma Intervention Study

To determine whether community pharmacist-initiated interventions containing a recommendation to adjust prescribed asthma therapy are more helpful to prescribers than similar communications without such a recommendation. Prospective, multicenter, quasi-experimental design with posttest. Wisconsin and Minnesota. 33 community and clinic pharmacies throughout the Coulee Region of Wisconsin and Minnesota enrolled eligible patients from October 1, 2004, to January 31, 2005. Patients were between 12 and 60 years of age, had used three or more short-acting beta-agonist (SABA) canisters with-in the previous 90 days, and did not meet any exclusion criteria. Based on an evaluation of each patient's inhaler technique and adherence to controller medications, pharmacists sent to the prescriber a fax containing a recommendation (for patients with proper technique and appropriate adherence to prescribed controller medications) or information (for those who had any combination of inappropriate inhaler technique or inappropriate adherence). Health care professionals' yes-or-no response to the question, "Do you find this form helpful for making clinical decisions?" Pharmacists offered to enroll 235 patients who were identified as meeting preliminary inclusion criteria. Of those, 112 people met exclusion criteria, 28 were not interested in their pharmacists' involvement, 13 stated that they did not have time to participate, 11 took the forms home but did not return them, and 11 other patients were excluded by the pharmacists for other reasons. The remaining 60 patients were in enrolled in the study, 60 faxes were sent from 16 pharmacies, and 40 of those were analyzed further. For 24 recommendation faxes sent, prescribers rated 15 as helpful (62.5%) and 4 as not helpful (16.7%). Of 16 informational faxes sent, 10 were marked helpful (62.5%) and 2 were marked not helpful (12.5%). Recommendation and informational faxes were overall helpful to health care professionals in making clinical decisions. Respondents found the two types of faxed interventions as equally helpful, suggesting that pharmaceutical care initiated by community pharmacists is helpful to prescribers.

Could interchangeable use of dry powder inhalers affect patients?

The aim of asthma treatment is optimal disease control. Poor asthma control results in considerable patient morbidity, as well as contributing to the considerable burden placed by the disease on healthcare budgets. There is a need for costs to be carefully scrutinised, with the switching of patients to inhaler devices with lower acquisition costs likely to be increasingly considered. However, before such practice becomes widespread, it is important to establish whether or not this could adversely impact on patients and the level of disease control. For approval to have been given, all marketed inhalers must have satisfied current regulatory requirements for devices. Full preclinical and clinical development programmes are not required when application is made for authorisation to market a new inhaler containing an existing chemical entity, although clinical equivalence testing must be used. Both beneficial and adverse effects should be tested, and the limits of equivalence must be clearly defined, based on therapeutic relevance. It should be noted that equivalence studies are invalid when the end point is not responding (i.e. at the top of the dose-response curve) and when equivalence limits approach or are equal to the magnitude of the drug effect. Approval on the basis of regulations designed to safeguard quality of dry powder inhalers does not mean that devices are interchangeable. When using an inhaler, there are many stages between the patient and the therapeutic effect, involving device design, pharmaceutical performance and patient behaviour. Regulations governing new devices cover only a few of the many factors affecting disease control. Furthermore, clinical trials to assess equivalence may not take into account factors in patient behaviour or variations in patient inhaler technique that may affect use of devices in real-life situations. When assessing the consequences of interchangeable use of dry powder inhalers on healthcare costs, it is important to ensure that the acquisition cost of the devices is not the only cost considered. Other costs that should be considered include the cost of time spent demonstrating to the patient how to use the new device, the cost of additional physician visits to address patient concerns and the management costs if disease control is adversely affected.

Targeting the Distal Lung in Asthma

Inflammation of the distal lung, which consists of the small airways (internal diameter <2 mm) and alveolar tissue, is an important feature of the asthma clinical syndrome comprising airway inflammation, airway hyperresponsiveness and bronchodilator-responsive expiratory airflow limitation. Support for this assertion is derived from histologic studies which have demonstrated evidence of inflammation in this anatomic compartment, along with additional studies, which have elucidated the radiologic and physiologic correlates of distal lung inflammation. Delivering inhaled drugs to this area is challenging and is dependent on a number of drug- and delivery device-related factors, as well as on a patient's inhaler technique and bronchial anatomy. Newer chlorofluorocarbon-free formulations of inhaled corticosteroids such as hydrofluoroalkane propelled metered-dose inhalers and dry powder inhalers appear to have certain advantages with regard to drug delivery that facilitate improved drug delivery to the distal lung. Mounting evidence indicates that recognition and treatment of distal lung inflammation may be key components of appropriate asthma pharmacotherapy.

Comparative Study of Different Inhaler Devices in Asthmatic Children

The inhaler is an important drug delivery system in the treatment of asthma, but inhaler technique is often inadequate. We assessed technique in children diagnosed with asthma, comparing the performance of three devices. In a cross-sectional survey, 523 children (271 boys, 252 girls, ages 5 to 12 years; mean+/-SD 7.53+/-1.79 years) demonstrated inhalation technique according to Netherlands Asthma Foundation criteria during a first visit to a primary care clinic in Abha, Saudi Arabia. Patients used the device with which they were most familiar (either pMDI, Turbuhaler or Diskus). Two hundred children (38% of total population) used a pMDI, while 323 (62% of total population) used one of the dry powder inhalers 173 (58%) the Turbuhaler and 150 (47%) the Diskus. Only 49 children (25% of the total population) completed the assessment without making a mistake. The remaining 474 (75% of the total population) performed one or more manuevers poorly. Only 80 children who used an MDI (40% of those using the device) completed 50% or more of the maneuvers correctly compared with 111 (69% of those using the device) and 100 (67% of those using the device) of those using the Turbuhaler and Diskus, respectively (P=0.001 for comparison of MDI with dry powder inhalers). Children whose mothers had intermediate school or higher education performed better than those whose mothers had less education (P=0.001). The father's education had no bearing on performance with the inhaler. The inhaler technique of most asthmatic children is poor, but technique is better in children who use a dry powder compared a metered-dose inhaler. The level of the mother's education is positively associated with better inhalation technique in the child.

Assessment of Inhalation Technique in Primary Care Asthmatic Patients Using Metered-Dose Inhalers with or without a Spacer

Asthma is a chronic disease with increasing morbidity and mortality. Although the development of metered-dose inhalers (MDIs) was a landmark in asthma management, their use is burdened by inappropriate training. Inadequate inhalation technique is reported in 24% to 89% of patients. We assessed how a sample of adult asthmatic patients seen in primary healthcare clinics (PHCs) in Riyadh used their metered-dose inhalers (MDI). We conducted a cross-sectional survey of asthmatic adults â yen 18 years of age who attended PHCs and used an MDI with or without a spacer device. Patient inhalation technique was observed independently by the primary researcher and a respiratory therapist using a checklist based on US (National Heart, Lung and Blood Institute) asthma management guidelines. The mean age of the 191 patients in the survey was 40.64 years (range, 18 to 80 years). Fifty-nine percent were females and 41% were males. Most (77%) were illiterate and most (86%) had received previous education on MDI inhalation technique. Ninety-three percent were using an MDI without a spacer, but none could use their MDI without committing at least one error in both groups. In patients using an MDI without a spacer, the most common error was not tilting the head backward slightly and breathing out to residual volume (85%), followed by not breathing in slowly (84%). In patients using an MDI with a spacer, the most common errors were not tilting the head back slightly and breathing out slowly to residual volume (77%), and not holding the breath for 10 seconds (77%). Despite that MDIs are a mainstay in the management of our asthmatic patients, inhalation technique is very poor among our patients.

Cross-infection and the use and decontamination of placebo inhalers

Historically, inhaled placebos have been provided by pharmaceutical companies and have been widely used by nurses both in primary and secondary care to teach respiratory patients how to use prescribed inhaled therapy. Over recent years, the author of this article has had concerns about the potential risk of cross-infection as a result of reusing placebos with disposable mouthpieces. This concern has been heightened by the lack of verbal and written guidance from the pharmaceutical companies that provide these placebos. There are no recognized protocols or guidelines on the most effective cleaning methods that would minimize or prevent cross-infection. The cleaning of large volume spacers, which are used to enhance a patient's inhaler technique, are particularly problematic as it is not possible to use a disposable mouthpiece with this device. In response to this problem, a cross-sectional, multicentre, regional audit was designed to identify the decontamination process adopted by nurses working in the fields of respiratory care and infection control. The audit outcome confirmed that nurses were using a number of different cleaning methods, with no sound evidence base to support their chosen methods of decontamination. This is an issue that requires further investigation and clarification if nurses are to continue assessing patients' techniques with inhaled devices.

An education programme for asthma and COPD patients conducted by a general practice assistant; a randomised controlled trial

Aim:To improve disease control and thereby health related quality of life (HRQoL) in patients with asthma or chronic obstructive pulmonary disease (COPD) in general practice, we developed and evaluated an education program conducted by a practice assistant. Methods: 272 Asthma and COPD patients were stratified by age and randomly assigned to the intervention (n=139) or control group (n=137). The intervention program consisted of training regarding inhalation technique, and patient centred information about the disease, medication, hyperreactivity, and coping with their disease. The control group received usual care. Measurements took place before randomisation and after one and two years. Outcome measures included HRQoL and disease symptoms. Furthermore, process measures included compliance, inhalation technique, coping and self-efficacy.Results:209 patients (77 %) completed at least one year follow-up. No differences regarding HRQoL and disease symptoms were observed between the intervention and the usual-care group. In addition, no differences were observed in compliance, coping, and self-efficacy. However, after one and two years the inhalation technique improved significantly (p<0.05) in the intervention group (adequate technique in respectively 62% and 71%) compared to the control group (respectively 42% and 59%).Conclusion:Our results show that an education by a practice assistant may result in an important improvement of inhalation technique in patients with asthma or COPD. However, no effects were found on HRQoL or disease symptoms.

Determinants of an incorrect inhalation technique in patients with asthma or COPD

Objective - To determine the prevalence of an incorrect inhalation technique and to examine its determinants among primary care patients with asthma or chronic obstructive pulmonary disease (COPD). Design - Cross-sectional study. Setting - 28 general practitioners in The Netherlands. Subjects - 558 asthma and COPD patients, aged 16-75 years. Main outcome measures - Inhalation technique was assessed using a standardised inhaler-specific checklist. Pulmonary function assessment and questionnaires were used to collect data about inhaler, patient and disease characteristics. Results - Overall, 24.2% of the patients made at least one essential mistake in their inhalation technique. The type of inhaler appeared to be the strongest independent determinant of an incorrect inhalation technique. Compared to patients using the Diskhaler, patients using the Rotahaler/Spinhaler, Turbuhaler, Metered Dose Inhaler (MDI) or Cyclohaler/Inhaler-Ingelheim were at significantly higher risk of making inhalation mistakes (odds ratios (OR) were 16.08, 13.17, 11.60 and 3.27, respectively). Other significant determinants of an incorrect inhalation technique were low emotional quality of life (OR =1.73) and being treated in a group practice (OR =2.26). Conclusions - An incorrect inhalation technique is common among pulmonary disease patients in primary care. Our study suggests that especially patients using the Rotahaler/Spinhaler, Turbuhaler or MDI, patients with emotional problems and patients in a group practice are at increased risk for an incorrect inhalation technique.

Educational intervention for correct pressurised metered dose inhaler technique in Trinidadian patients with asthma

Correct pressurised metered dose inhalers (pMDI) usage is reportedly sub-optimal in patients and data for Caribbean populations is not available. We studied proficiency of inhaler use in Trinidadian patients, and determined sub-groups to be targeted for educational interventions. Inhaler use by 331 consecutive stable patients with airway disease (over 7 years) was observed and marked on a standard checklist. From direct observation only 41% of patients correctly inhaled, though 92% were confident of accurate technique. Few elderly patients (6%) received appropriate instructions on inhaler technique and only 35% ( n=23/66) understood the rationale for two different inhaler therapies ( P<0.001). More children (33%) and elderly patients (21%) reported escaping drug with use. Multiple regression analysis indicated the independent predictors of correct pMDI were age ( P<0.01) and correct understanding of different inhalers. Intensive patient education in Trinidadian children and elderly patients with airway disorders can enable active participation in disease management and maximal benefit from medication.

The Protective Effect of Salbutamol Inhaled Using Different Devices on Methacholine Bronchoconstriction

To determine the protective effect of salbutamol, 100 microg, inhaled by different devices (pressurized metered-dose inhaler [pMDI; Ventolin; GlaxoWellcome; Greenford, UK], pMDI + spacer [Volumatic; GlaxoWellcome], or breath-activated pMDI [Autohaler; 3M Pharmaceuticals; St. Paul, MN]) on bronchoconstriction induced by methacholine. Randomized, double-blind, cross-over, placebo-controlled study. Eighteen subjects with stable, moderate asthma, asymptomatic, receiving regular treatment with salmeterol, 50 microg bid, and inhaled beclomethasone dipropionate, 250 microg bid, in the last 6 months, with high hyperreactivity to methacholine (baseline provocative dose of methacholine causing a 20% fall in FEV(1) [PD(20)] geometric mean [GM], 0.071 mg). Subjects were classified into two groups: subjects with incorrect (n = 5) pMDI inhalation technique, and subjects with correct (n = 13) inhalation technique. After cessation of therapy for 3 days, all subjects underwent four methacholine challenge tests, each test 1 week apart, each time 15 min after inhalation of salbutamol, 100 microg (via pMDI, pMDI + spacer, or Autohaler), or placebo. The protective effect on methacholine challenge test was evaluated as the change in the PD(20), and expressed in terms of doubling doses of methacholine in comparison with placebo treatment. The PD(20) was significantly higher after salbutamol inhalation than after placebo inhalation, but no significant difference was observed among the three different inhalation techniques. Only when salbutamol was inhaled via pMDI + spacer, PD(20) was slightly but not significantly higher (pMDI GM, 0.454 mg; pMDI + spacer GM, 0.559 mg; and Autohaler GM, 0.372 mg; not significant [NS]) than other inhalation techniques. Similar results (mean +/-SEM) were obtained with doubling doses of methacholine (pMDI, 2 +/- 0.47; pMDI + spacer, 3 +/- 0.35; and Autohaler, 2.4 +/- 0.40; NS). No significant difference was found among techniques when subjects with correct or incorrect inhalation technique were separately considered. Our data show that the protective effect of salbutamol, 100 microg, on methacholine-induced bronchoconstriction is not affected by the different inhalation techniques, although inhalation via pMDI + spacer tends to improve the bronchoprotective ability of salbutamol. These data confirm the clinical efficacy of salbutamol, whatever the device, and the patient's inhalation technique.

Metered-dose inhaler technique of patients in an urban ED: Prevalence of incorrect technique and attempt at education

The metered-dose inhaler (MDI) techniques of 125 asthma patients who presented to a county hospital emergency department (ED) were evaluated. Correct technique was divided into 7 steps. Twenty-one percent of the patients performed all 7 steps correctly. Mean number of steps ± SD performed correctly was 4.8 ± 1.7. Verbal individualized instruction was used to improve the technique of patients whose technique was less than perfect. The instruction required a mean ± SD of 8.3 ± 5.8 minutes (range, 0 to 30) for all 7 steps to be done correctly at least once. All patients were able to perform all steps correctly after instruction. The amount of time required for teaching was proportional to the number of steps performed incorrectly. The Vitalograph Aerosol Inhalation Monitor was used to verify correct patient technique and as a teaching aid with variable success. Education in proper use of the MDI is important in the overall care of the asthma patient; however, instruction requires a definite time commitment and may not be feasible for all patients in a busy ED. For some patients, alternatives that require less lengthy instruction, such as the use of breath-actuated devices, spacers, and reservoirs, may be required.

The Evolution of Inhaler Technology

Historically, the evolution of inhalation therapy can be traced to India 4000 years ago. The antecedents of contemporary inhalation therapy, however, began in the nineteenth-century industrial age with the invention of the glass bulb nebulizer. From there, inhaler technology evolved along two pathways characterized by refinements in existent nebulizer technology and the invention of a portable inhalation device, the metered-dose inhaler (MDI). More recently, growing recognition of problems associated with MDI use (chiefly, its reliance on coordinated patient inhalation and actuation technique) led to modifications in the MDI itself with auxiliary devices (spacers) and the development of new inhaler systems--dry powdered inhalers (DPIs) and the breath-actuated metered-dose inhaler (BAI-MDI).

Cerebral blood flow asymmetry in the detection of extracranial cerebrovascular disease.

Regional cerebral blood flow was measured by the 133Xe inhalation technique in patients with unilateral carotid occlusion, unilateral carotid occlusion and contralateral carotid stenosis, bilateral carotid occlusion, or normal arteriograms. After adjusting for age, sex, and history of stroke, hemispheric blood flow asymmetry was shown to be a predictor of unilateral carotid occlusion with a sensitivity of 80.6% and a specificity of 80.5%. Asymmetry of regional cerebral blood flow is useful in the assessment of patients with extracranial cerebrovascular disease.