| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Guest Access | Sign In via User Name/Password
|
|
|
|||||||
Guest Access | Sign In via User Name/Password |
|||||||||
From The Asthma Centre, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.
Correspondence to: Stanley Epstein, MD, Toronto Western Hospital, 399 Bathurst Street, EC 4–022, Toronto, Ontario, M5T 2S8, Canada
 |
Abstract |
|---|
 TOP Abstract IntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
Method: We used trained observers to assess the handling of a specific multi-dose dry powder inhaler (Turbuhaler; AstraZeneca Canada; Mississauga, ON) by patients currently using the device for the management of their asthma. Fourteen discrete steps were scored independently by two observers simultaneously. Patients were divided into two groups for analysis: those who had received formal instruction in the use of the inhaler at The Asthma Centre and those who had received no formal instruction in the community.
Results: There was no significant difference between the formally trained groups and control groups in the percentage of handling steps performed correctly (79% vs 78%, respectively; p > 0.05). Fewer than 50% of patients in both groups demonstrated optimal breath-holding when using the device.
Conclusion: Patient handling of Turbuhaler was generally good, with no evidence that a structured education intervention offered an advantage over the usual education incidental to the prescribing or dispensing process. The most common handling flaw, suboptimal breath-holding, is not specific to this device and is of uncertain clinical significance.
Key Words: asthma • device • patient education
|
Introduction |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
One commonly used dry-powder inhaler is the Turbuhaler (AstraZeneca Canada; Mississauga, ON). It is a breath-activated, multiple-dose inhaler used to deliver terbutaline, formoterol, budesonide, and albuterol.8 9 10 11 This device has been shown to be an effective delivery system with potential advantages over conventional pressurized metered-dose inhalers in the maintenance treatment of asthma.12
However, a survey of physician and nonphysician health-care providers has shown that the Turbuhaler is poorly used and not well understood by caregivers who might be in a position to instruct the patient with asthma in optimal use of the device.13 14 Therefore, we undertook the present cross-sectional observational study to examine the use of Turbuhaler in the clinical setting by patients with asthma. We asked two groups of patients to demonstrate their technique for using this device. One group had received formal instruction in Turbuhaler usage by a trained nurse educator. The other group had received no such formal training and served as a control group.
|
Materials and Methods |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
This protocol was approved by the Human Ethics Committee of the Toronto Hospital and was not altered during the study. Each subject signed a consent form after full explanation of the study. Only individuals who could understand English without an interpreter were included after expressing their willingness to take part in the study.
Protocol
Individuals were asked to self-administer two inhalations from a
placebo Turbuhaler while being observed simultaneously by two trained
observers in a quiet area. These observers were not involved in the
subjects’ previous instruction but were trained by the same nurse
educator who had instructed the subjects, and they had received
approximately 1 hour of initial and follow-up instruction. Throughout
the study, observations were made by five observers who were research
assistants and not health-care deliverers. For each subject, the two
observers recorded their assessments of technique independently on
separate observation sheets. Thirteen distinct steps were scored for
both the first and second puff from a Turbuhaler. These included the
following: (1) removing the cover before the first puff; (2) not
shaking the inhaler; (3) holding the inhaler upright for priming; (4)
turning the wheel correctly to the right; (5) then turning the wheel
correctly to the left until there is a click; (6) breathing out; (7)
breathing away from the inhaler prior to inhalation; (8) putting the
mouthpiece between the lips; (9) breathing in deeply; (10) breathing
forcefully through the mouth; (11) removing the inhaler from the mouth;
(12) holding the breath for more than 5 s before (13) exhaling;
and (14) then replacing the cover after the second puff. These
maneuvers were based on the manufacturer’s recommendations and
previously published studies of the optimal
technique.13
14
After the demonstration of the technique, one of the observers administered a questionnaire concerning duration and frequency of Turbuhaler usage. The observers also asked about Turbuhaler instruction that the subject had received, including the source of instruction and the time of the last instruction before the study, about the subject’s use of other inhalers, and about the subject’s asthma.
Statistical Analysis
To compare demographics and disease characteristics between the
formally trained groups and control groups, the two-sample
t-test was used when the data were normally distributed,
otherwise the Mann-Whitney test was used. To assess the interobserver
agreement between each pair of the five trained observers, 
and
percent agreement were calculated.16
To determine whether
the two groups varied significantly in demonstrated technique for each
step, Fisher’s Exact Test was used. Also, an overall performance score
based on all steps combined was calculated. A two-sample
t-test was then used to detect differences between the two
groups. Multiple linear regression was used to determine whether
demographics or disease characteristics were predictive of performance
scores. McNemar test was used to show that there was no difference
between the first and second puff. Therefore, the multiple linear
regression utilized the data from the first puff. It was estimated that
42 subjects would need to be analyzed in each group to detect a 78%
reduction in technique at conventional levels of power and
significance.
|
Results |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
|
|
|
|
|
Discussion |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
However, few patients performed all of the steps correctly. Only 12% of the trained patients performed 100% of the 13 steps of the first puff correctly; whereas only 11% of the control group achieved this benchmark. Step 12, holding the breath for 5 s or more, was the most commonly missed step. This was an objective measurement performed using a stopwatch. Breath-holding after drug inhalation may increase drug deposition in the lower airway.18 However, the impact of breath-holding appears to be modest, with some studies of dry powder inhalers showing no difference in drug deposition or bronchodilator effect between breath-holding maneuvers and nonbreath-holding maneuvers.19 20
We were intrigued to see that there was little difference in the adequacy of Turbuhaler handling between patients who had arrived from the community to an asthma center setting for the first time and patients who had participated previously in formal inhaler instruction. Of course, patients who received their Turbuhaler in the community without further instruction by a nurse educator were not necessarily without instruction in the correct use of the inhaler. Typically, such patients learned about usage from their prescribing physician, from their pharmacy, or from the package insert. The fact that such brief instruction sessions produced similar performance as from patients trained in usage suggests that the device is intuitively obvious and requires minimal instruction time for the average adult patient.
Previous studies of the handling of Turbuhaler by health professionals suggested that caregivers are frequently ignorant of optimal Turbuhaler usage.13 14 We thought that this might be reflected in similar mistakes among patients using this device. A lack of mishandling of the Turbuhaler by such patients may have several explanations. First, earlier studies with health-care professionals were performed when health-care professionals were less familiar with Turbuhaler use. Second, it is possible that the patients in our study received their prescriptions from physicians particularly interested in the correct use of inhaler devices. Dry-powder inhalers are less frequently prescribed than conventional pMDIs, and their use might reflect a greater knowledge of inhalation devices by the physician.
Although we did not compare the patient use of conventional pressurized metered-dose inhalers with the use of the Turbuhaler, the usually adequate scores we saw with the Turbuhaler in this study are in contrast to numerous previously published reports of poor patient handling of pMDIs.7 21 22 The pMDI is often difficult for patients to use because it requires coordination of ventilation with a fast-moving aerosol spray. This is not necessary with dry-powder inhalers. Our study provides some reassurance to physicians who are reluctant to have patients use two or more different types of inhaler. We could find no evidence that the concurrent use of a pMDI influenced Turbuhaler handing among our subjects. Our study also showed that there was need for only one observer to evaluate single puff inhaler handling, a finding that is in contrast to earlier studies.23
Our study was limited because it did not attempt to measure the impact of various types of mishandling on drug deposition or the impact on the resulting pharmacologic effect. Our study may have underestimated the presence of some type of mishandling of the device. We did not use flow measuring devices to quantify inspiratory flow rate. It is possible that some of our patients, whom we thought to have adequate inspiration flow rates, did not achieve optimal velocity to break up and deliver the powdered medication. Also, we assessed handling in only a single session. Some types of Turbuhaler mishandling might have impact only with chronic use. For example, exhalation into a reservoir-type dry-powder device can produce a condition of excess humidity with clumping and suboptimal delivery of medication.
For several decades, surveys of patients with asthma have shown that the use of conventional pMDIs is often suboptimal. The present survey offers some reassurance that the newer generation of dry-powder inhalers is better used by patients. Unfortunately, some problems of improper technique remain. Further research will help to explain which areas of concern in patient handling of dry-powder inhalers are clinically significant and will show how they can be overcome.
|
Acknowledgements |
|---|
|
Footnotes |
|---|
The study was financed by AstraZeneca Canada. One of the authors (K.R.C.) has received consultant fees from AstraZeneca Canada. All of the other authors have no professional or financial interest in AstraZeneca Canada.
Received June 27, 2000; revision accepted May 15, 2001.
|
References |
|---|
|
TOPAbstractIntroductionMaterials and MethodsResultsDiscussionReferences |
|---|
This article has been cited by other articles:
|
|
 |
|
  K. R. Chapman, T. H. Voshaar, and J. C. Virchow Inhaler choice in primary practice Eur. Respir. Rev., December 1, 2005; 14(96): 117 - 122. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B. K. Rubin What Does It Mean When a Patient Says, "My Asthma Medication Is Not Working?" Chest, September 1, 2004; 126(3): 972 - 981. [Full Text] [PDF]
|
|
|
|
 |
|
 Patients Handle Dry-Powder Inhalers As Well As They Do Similar Devices Journal Watch Emergency Medicine, January 15, 2002; 2002(115): 4 - 4. [Full Text]
|
|
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
