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Demonstrated Use of Metered-Dose Inhalers and Peak Flow Meters by Children and Adolescents With Acute Asthma Exacerbations
Richard J. Scarfone, MD;
Geoffrey A. Capraro, MD;
Joseph J. Zorc, MD;
Huaqing Zhao, MA
Arch Pediatr Adolesc Med. 2002;156:378-383.
ABSTRACT
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Objectives To determine the ability of children and adolescents with acute asthma
exacerbations to adhere to national guidelines for proper metered-dose inhaler
(MDI) and peak flow meter (PFM) technique and to define characteristics associated
with improper use.
Design A prospective study in which the patients were instructed to use a placebo
MDI or a PFM in the emergency department exactly as at home. Technique was
graded on the basis of performance of specific steps recommended by national
guidelines.
Setting and Participants Children and adolescents (aged 2-18 years) with acute asthma exacerbations
in the emergency department of an urban children's hospital with acute asthma.
Results Thirty-three (45.2%) of 73 patients using an MDI (MDI group) demonstrated
multiple steps improperly compared with 60 (44.4%) of 135 using an MDI with
a holding chamber (MDI-HC group; P = .92). In the MDI group, young
ages of the patients (P<.008) and the parents (P<.003)
were associated with improper use. In the MDI-HC group, factors independently
and significantly associated with improper use were no hospitalizations within
the past year, parent assistance of the patient with MDI-HC use, and nondaily
use of the MDI-HC. Also, 165 (82.9%) of 199 children who, per national guidelines,
should be using a PFM at home, did not. Eighty-two (73.9%) of 111 patients
demonstrated perfect performance of all PFM steps.
Conclusions Among children with acute asthma, we found high rates of improper MDI
use and PFM underuse. A greater emphasis must be placed on teaching methods
to optimize drug delivery and to instruct patients about the importance of
self-monitoring of disease severity.
INTRODUCTION
IN 1997, the National Heart, Lung, and Blood Institute (NHLBI) of the
National Institutes of Health published revised guidelines for the diagnosis
and management of asthma.1 Key recommendations
of these guidelines are the administration of short-acting bronchodilators
by means of a small-volume nebulizer or a metered-dose inhaler (MDI) and monitoring
of peak expiratory flow (PEF) using a peak flow meter (PFM) to help determine
the degree of illness and to define appropriate treatment plans.
The extent to which children with acute asthma exacerbations properly
use MDIs and PFMs as recommended by these national guidelines has not been
well studied, and predictors of poor technique have not been identified. We
assessed a cohort of children with an asthma exacerbation of sufficient severity
to necessitate emergency department (ED) care. We sought to determine the
ability of children who routinely used MDIs to adhere to NHLBI guidelines
for proper technique and to define characteristics associated with improper
use. With respect to PFMs, we sought to determine primary care provider (PCP)
prescribing patterns, overall utilization practices for PFM use, knowledge
of score interpretation, and ability to adhere to NHLBI guidelines for proper
technique.
PATIENTS AND METHODS
SETTING AND PATIENTS
The study took place in the ED of an urban tertiary care children's
hospital. A convenience sample was enrolled prospectively from 8 AM to midnight,
7 days per week. Children and adolescents aged 2 to 18 years with an asthma
exacerbation were included if they had a history of at least 2 episodes of
wheezing that required bronchodilator therapy and presented with an English-speaking
adult. Non–English-speaking families constituted less than 1% of the
total ED population and were excluded because of the concern that they may
not fully understand study instructions. Children who received continuous
nebulized albuterol sulfate, who had cystic fibrosis or congenital heart disease,
or who had been enrolled previously were also excluded. The hospital's institutional
review board approved the study.
Emergency department physicians not involved with the study decided
treatment for the study patients and prescribed medications at ED discharge.
After treatment had been initiated, parents were approached by one of the
investigators or a trained research assistant for study enrollment. Research
assistants were taught the proper use of the MDI and the PFM before the start
of the study. Fifty patients were enrolled during a prestudy pilot phase to
allow investigators to develop their interviewing and observational skills,
and meetings were held throughout the trial to reinforce proper MDI and PFM
techniques. Some patients in the study demonstrated MDI and PFM use.
Persistent asthma was defined by the following symptoms: coughing, wheezing,
shortness of breath, chest tightness, and rapid or troubled breathing. One
or more daytime symptoms at least 3 days per week or 1 or more nighttime symptoms
at least 3 nights per month was defined as persistent asthma.1
All other symptoms were defined as mild, intermittent asthma.
MDI GROUPS
Patients who reported owning an MDI and using it daily or as needed
to manage their asthma were identified. They were given an MDI placebo in
the ED and asked to demonstrate it "exactly as you would use it at home,"
even if they had not used it just before the ED visit. Similarly, patients
reporting the regular use of an MDI with a holding chamber (MDI-HC) were provided
the AeroChamber or AeroChamber With Mask MDI (Forest Pharmaceuticals, Inc,
St Louis, Mo) and asked to demonstrate its use. Parents and patients were
aware that the placebo MDI contained propellants but no active ingredients.
The inhalation aerosol was identical in size and shape to that of widely available
MDIs used to deliver ß2-agonists.
The NHLBI recommends the following steps to optimize medication delivery
via MDIs1: (1) shake the MDI before use; (2)
exhale completely before actuation; (3) actuate once at the start of an inhalation;
(4) inhale slowly; (5) hold your breath after inhalation; and (6) ensure a
ratio of inhalation to actuation of 1:1.
Investigators recorded their observations of the MDI demonstration,
indicating which of the 6 steps the patients successfully completed. Parents
were allowed to assist their children as needed.
Patients who regularly used a holding chamber with a face mask underwent
assessment for the proper completion of steps 1 to 5 above for the first inhalation
and the following steps: (6) ensure a minimum ratio of inhalations to each
actuation of 5:11 and (7) maintain a tight
seal with the mask around the mouth and nose.
We assessed a number of variables to determine whether any were significantly
associated with improper MDI use. Morbidity factors included persistent disease
as defined by the NHLBI, frequency of hospitalizations or ED visits for asthma
in the past 12 months, severity of asthma exacerbation as assessed at ED triage,
and frequency of restricted activity or missed days of school or work. Patient
factors included age, sex, race, insurance status, and frequency of home MDI
use. Parent factors included age, history of asthma, education, and supervision
of the child's MDI use. Primary care provider factors included demonstration
of MDI use or provision of written or verbal instructions for MDI use.
PFM GROUP
We identified a separate cohort of patients who, per the NHLBI criteria,
should use PFMs to monitor asthma exacerbations. These included children 5
years or older with moderate to severe persistent asthma. They were asked
about PFM prescribing patterns of their PCPs and their practices and knowledge
regarding proper use of PFMs.
Those who reported having a PFM at home to manage their asthma (even
if they had not used it just before this ED visit) were identified. They were
provided a Pocketpeak PFM (Ferraris Medical Inc, Holland, NY) in the ED and
asked to demonstrate its use "exactly as you would use it at home." Parents
were allowed to assist their children as needed. The NHLBI recommends performing
the following steps for proper recording of the PEF using a PFM1:
(1) move the indicator to 0; (2) take the deepest inspiration possible; (3)
close your lips around the mouthpiece; and (4) blow hard and fast.
Investigators recorded their observations of PFM use, indicating which
steps were successfully completed.
STATISTICAL ANALYSIS
We used univariate tests to assess the association between factors and
improper MDI demonstration. Logistic regression was performed to determine
independent associations with improper MDI use. We used  2
or Fisher exact tests to analyze categorical variables and the t test for continuous data. We analyzed data using Epi Info (Version
6.04b; Centers for Disease Control and Prevention, Atlanta, Ga) and STATA
statistical software (Version 6.0; Stata Corp, College Station, Tex).
RESULTS
MDI GROUPS
As part of a larger and separate study in which children and adolescents
with asthma were asked questions about their adherence to asthma home-management
guidelines, 433 patients were interviewed in the ED. Of these, 208 met inclusion
criteria for the MDI demonstration and agreed to demonstrate its use in the
ED. Seventy-three (35.1%) reported using an MDI without a holding chamber
(MDI group) at home. One hundred thirty-five (64.9%) used an MDI with a holding
chamber (MDI-HC group), and of these, 61 (45.2%) regularly used a face mask.
The 2 groups underwent separate analysis to determine what impact, if any,
a holding chamber had on demonstrated use.
Both groups were similar at entry except that patients in the MDI group
were significantly older (P .001; Table 1). Also, within each group, no significant differences were
found in patient disposition from the ED (Table 1).
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Table 1. Patient Characteristics of the MDI Groups at Entry*
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Eighteen patients (24.7%) in the MDI group performed all steps perfectly
compared with 32 (23.7%) in the MDI-HC group (P =
.88). Similarly, in the MDI group, 33 patients (45.2%) performed multiple
( 2) steps improperly, compared with 60 (44.4%) in the MDI-HC group (P = .92). Figure 1
and Figure 2 display the proportion
of patients in each group who demonstrated improper performance of specific
steps.
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Figure 1. Steps performed improperly in
the group using a metered-dose inhaler (MDI). Steps are described in the "MDI
Groups" subsection of the "Patients and Methods" section.
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Figure 2. Steps performed improperly in
the group using a metered-dose inhaler (MDI) with a holding chamber. Steps
are described in the "MDI Groups" subsection of the "Patients and Methods"
section.
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In the MDI group, young age of the patients (P<.008)
and the parents (P<.003) were associated with
improper performance of multiple steps. Similarly, in the MDI-HC group, young
age of the patients (P<.001) and the parents (P<.03) were associated with improper use. Table 2 displays improper use rates stratified by age.
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Table 2. Rates of Improper Use*
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Among those in the MDI-HC group, we found an association between the
parent assisting the patient with use of the MDI-HC and improper use (Table 3). On the other hand, hospitalizations
and ED visits within the past year and daily MDI-HC use were inversely related
to improper use (Table 3). Of
the 6 factors having a significant association with technique, 3 remained
significantly, positively, and independently associated with improper MDI-HC
use when multivariate logistic regression analysis was performed. These included
no hospitalizations within the past year, the parent assisting the patient
with MDI-HC use, and nondaily MDI-HC use (Table 4).
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Table 3. Clinical Factors and Their Association With Improper Performance
of Multiple Steps*
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Table 4. Multiple Logistic Regression Analysis of Risk Factors for
Improper Use in the MDI-HC Group*
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PFM GROUP
We interviewed 305 patients 5 years or older as part of the larger,
separate study. Of these, 199 met the NHLBI guidelines for regular PFM use.
One hundred twenty-five (62.8%) had been prescribed a PFM by their PCP, and
34 (27.2%) of these had used it at home to monitor the asthma attack that
prompted the ED visit. Thus, 165 (82.9%) of 199 children who (per the NHLBI
guidelines) should be using a PFM to monitor degree of illness had failed
to do so.
Among the 125 children who had been prescribed a PFM, 38 (30.4%) tried
to contact their PCP at the onset of this wheezing attack to receive management
advice, 28 (22.4%) successfully reached the PCP, and 2 (1.6%) were advised
to monitor their symptoms by using their PFM.
Among the patients who reported regular use of a PFM during or between
asthma exacerbations, 22 (28.9%) of 76 patients did not know that PFM measurement
should be performed while standing; 28 (35.4%) of 79 did not know that 3 attempts
should be made; 30 (39.5%) of 76 did not know that the highest value should
be accepted; and 28 (35.9%) of 78 did not know the score that signified the
need for more medication.
A subset of 111 patients 5 years or older reported having a PFM at home
and agreed to demonstrate its use in the ED. The mean age of this group was
11 years (SD, 3.2 years); 58% were male; 95% were African American; and 59%
were uninsured or insured by Medicaid managed care. In the preceding 12 months,
asthma had led to at least 1 hospitalization for 51 (45.9%). For the current
exacerbation, 40 patients (36.0%) were ultimately hospitalized to the general
ward or to a 23-hour observation unit.
When asked to demonstrate their PFM technique, 82 (73.9%) did so perfectly. Figure 3 displays the proportion of children
who demonstrated improper performance of specific PFM steps.
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Figure 3. Steps performed improperly in
the group using a peak flow meter (PFM). Steps are described in the "PFM Group"
subsection of the "Patients and Methods" section.
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COMMENT
MDI GROUPS
Among patients who used an MDI regularly, only about one quarter were
judged to use perfect technique during an asthma exacerbation and almost half
performed multiple steps improperly. Holding chambers were underused, and
although they improve drug delivery to the distal airways, the use of a holding
chamber with or without a face mask did not influence overall performance
in this study. Improper use was most pronounced among the youngest children.
In the MDI group, too few factors were associated with improper use
for further analysis. However, patients in the MDI-HC group were more likely
to use MDIs improperly if they had not been hospitalized recently. Perhaps
proper MDI technique was taught and reinforced by physicians, nurses, and
respiratory therapists during hospitalizations. Patients requiring parental
assistance were more likely to use the MDI-HC improperly. Assistance is undoubtedly
required for younger children who are less able to adhere to the NHLBI guidelines
for proper use. Also, these children may have behavioral or motor problems
that cannot be overcome with parental assistance. Finally, those who did not
use an MDI-HC daily were more likely to demonstrate improper use.
No attempts to quantify the delivery of aerosolized medication were
made. However, aerosol deposition is critically dependent on a patient's inhalation
technique. Numerous investigators have demonstrated that a slow inspiration
maximizes the effect of the MDI2-6
and that a breath hold is needed to permit time for aerosol particles to settle
in the distal airways.2-3,7
For example, in one trial, a 50% difference between efficient and nonefficient
users was found in the mean improvement in forced expiratory volume in 1 second
after 2 puffs of drug.8 In the present study,
since no one step was particularly troublesome for children, education efforts
reinforcing proper performance of each step must be made.
Many studies have demonstrated comparable outcomes for children in the
ED who receive ß2-agonists by means of an MDI-HC or a small-volume
nebulizer.9-20
Studies based in the ED such as these represent ideal conditions in which
children are instructed on the proper use of the MDI-HC just before enrollment
and may not reflect conditions as they actually exist for children with acute
asthma exacerbations at home or in most urban EDs. In addition, these studies
may highlight the inefficiency of drug delivery by means of a small-volume
nebulizer, rather than proving the advantages of delivery by means of an MDI-HC.
Attempts were made to minimize the role that unfamiliar equipment might
have played in influencing outcomes. The placebo MDI was of a standard size
and shape, only patients who were experienced with MDI use were enrolled,
and parents were allowed to assist. These factors should have increased the
proportion of patients who demonstrated perfect use; thus, improper use may
be more prevalent in the general population. On the other hand, the study
population, by virtue of requiring ED care, might represent a group that is
particularly unskilled with MDI use.
Finally, the degree of illness may have affected the ability of children
to use the MDI properly. However, MDIs are recommended as first line therapy
to treat children with acute asthma exacerbations, and that is precisely the
group we wished to study. Also, more than 80% of children were mildly or moderately
ill, just one third required hospitalization, and severity of illness was
not associated with improper use, making it unlikely that degree of illness
played a major role the rate of improper use. However, these results may not
be generalizable to children with milder exacerbations or with chronic stable
asthma.
PFM GROUP
A few studies have questioned whether patients have better outcomes
with PEF-based asthma management plans.21-22
However, other investigators have found that PEF monitoring results in lower
symptom scores and less use of maintenance therapy23
or improved morbidity variables.24 Lahdensuo
et al25 found a reduction in missed days of
work, a better quality of life, and less use of oral corticosteroids. Furthermore,
the NHLBI Expert Panel encourages patients to establish their personal best
PEF and use it as the basis of their asthma action plan, as "short-term daily
peak flow monitoring is helpful for assessing the severity of a patient's
asthma."1 The PEF depends on effort and technique;
therefore, "patients need instructions, demonstrations, and frequent reviews
of technique."1
In a study assessing inner-city children aged 4 to 9 years with asthma,
just 15% of parents reported that their child's physician had recommended
a PFM.26 Just 6% of patients actually obtained
a PFM, and 1% reported measuring a PEF in response to an asthma attack.26 These data and those reported in the present study
show that although the PFM is a simple tool that is easy to use, the underprescription
and underuse of PFMs and a lack of knowledge regarding score interpretation
limit their potential impact on asthma self-management.
CONCLUSIONS
One decade has passed since the publication of the first set of NHLBI
asthma guidelines. This should have been ample time for the incorporation
of these guidelines into asthma management programs, but we found a high degree
of nonadherence to and lack of knowledge of the key components of the guidelines.
These results point to a need for greater emphasis on teaching methods to
optimize drug delivery, especially among young children, and instructing patients
about the importance of self-monitoring of disease severity.
| What This Study Adds
To our knowledge, this is the first study to critically assess the step-by-step
technique in the use of MDIs or PFMs among children in the ED with acute asthma.
We found a high rate of improper MDI use and identified factors associated
with improper use. We found that PFMs were used properly by most children,
but were underprescribed and underused. Thus, we have identified areas in
which physicians, nurses, and respiratory therapists can focus their asthma
educational efforts.
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AUTHOR INFORMATION
Accepted for publication December 27, 2001.
We thank Rosie Roundtree and Auria Rosa for their assistance with data
entry and manuscript preparation.
Reprints are not available from the authors.
From the Departments of Pediatrics (Drs Scarfone and Zorc) and Biostatistics
and Epidemiology (Mr Zhao), University of Pennsylvania School of Medicine,
and the Division of Emergency Medicine, The Children's Hospital of Philadelphia,
(Drs Scarfone and Zorc), Philadelphia; and the Department of Pediatrics, Boston
University School of Medicine, and the Division of Pediatric Emergency Medicine,
Boston Medical Center, Boston, Mass (Dr Capraro).
REFERENCES
| |
1. Murphy S. Guidelines for the Diagnosis and Management of Asthma. Bethesda, Md: National Institutes of Health, National Heart, Lung,
and Blood Institute; 1997. Report 97-4051.
2. Newman SP, Pavia D, Clarke SW. Simple instructions for using pressurized aerosol bronchodilators. J R Soc Med. 1980;73:776-779.
ISI
| PUBMED
3. Dolovich M, Ruffin RE, Roberts R, Newhouse MT. Optimal delivery of aerosols from metered dose inhalers. Chest. 1981;80(6 Suppl):911-915.
4. Lawford P, McKenzie D. Pressurised bronchodilator aerosol technique: influence of breath-holding
time and relationship of inhaler to the mouth. Br J Dis Chest. 1982;76:229-233.
ISI
| PUBMED
5. Grainger JR. Correct use of aerosol inhalers. Can Med Assoc J. 1977;116:584-585.
PUBMED
6. Woolf CR. Correct use of pressurized aerosol inhalers [letter]. Can Med Assoc J. 1979;121:710, 714.
7. McFadden ER Jr. Improper patient techniques with metered dose inhalers: clinical consequences
and solutions to misuse. J Allergy Clin Immunol. 1995;96:278-283.
FULL TEXT
|
ISI
| PUBMED
8. Lindgren S, Bake B, Larsson S. Clinical consequences of inadequate inhalation technique in asthma
therapy. Eur J Respir Dis. 1987;70:93-98.
ISI
| PUBMED
9. Freelander M, Van Asperen PP. Nebuhaler versus nebulizer in children with acute asthma. Br Med J (Clin Res Ed). 1984;288:1873-1874.
10. Fuglsang G, Pedersen S. Comparison of Nebuhaler and nebulizer treatment of acute severe asthma
in children. Eur J Respir Dis. 1986;69:109-113.
ISI
| PUBMED
11. Pendergast J, Hopkins J, Timms B, Van Asperen P. Comparative efficacy of terbutaline administered by Nebuhaler and by
nebulizer in young children with acute asthma. Med J Aust. 1989;151:406-408.
ISI
| PUBMED
12. Ba M, Spier S, Lapierre G, Lamarre A. Wet nebulizer versus spacer and metered dose inhaler via tidal breathing. J Asthma. 1989;26:355-358.
ISI
| PUBMED
13. Lee N, Rachelefsky G, Kobayashi RH, et al. Comparison of efficacy and safety of albuterol administered by power-driven
nebulizer (PDN) versus metered-dose inhaler (MDI) with Aerochamber and mask
in young children with asthma [abstract]. J Allergy Clin Immunol. 1991;87:307.
14. Kerem E, Levison H, Schuh S, et al. Efficacy of albuterol administered by nebulizer versus spacer device
in children with acute asthma. J Pediatr. 1993;123:313-317.
FULL TEXT
|
ISI
| PUBMED
15. Lin YZ, Hsieh KH. Metered dose inhaler and nebulizer in acute asthma. Arch Dis Child. 1995;72:214-218.
FREE FULL TEXT
16. Parkin PC, Saunders NR, Diamond SA, Winders PM, Macarthure C. Randomized trial spacer vs nebulizer for acute asthma. Arch Dis Child. 1995;72:239-240.
FREE FULL TEXT
17. Chou KJ, Cunningham SJ, Crain EF. Metered-dose inhalers with spacers vs nebulizers for pediatric asthma. Arch Pediatr Adolesc Med. 1995;149:201-205.
FREE FULL TEXT
18. Williams JR, Bothner JP, Swanton RD. Delivery of albuterol in a pediatric emergency department. Pediatr Emerg Care. 1996;12:263-267.
ISI
| PUBMED
19. Butz AM, Eggleston P, Huss K, Kolodner K, Rand C. Nebulizer use in inner-city children with asthma: morbidity, medication
use, and asthma management practices. Arch Pediatr Adolesc Med. 2000;154:984-990.
FREE FULL TEXT
20. Amirav I, Newhouse MT. Metered-dose inhaler accessory devices in acute asthma: efficacy and
comparison with nebulizers: a literature review. Arch Pediatr Adolesc Med. 1997;151:876-882.
FREE FULL TEXT
21. Effectiveness of routine self monitoring of peak flow in patients with
asthma: Grampian Asthma Study of Integrated Care (GRASSIC). BMJ. 1994;308:564-567.
FREE FULL TEXT
22. Jones KP, Mullee MA, Middleton M, Chapman E, Holgate ST and the British Thoracic Society Research Committee. Peak flow based asthma self-management: a randomized controlled study
in general practice. Thorax. 1995;50:851-857.
FREE FULL TEXT
23. Woolcock AJ, Yan K, Salome CM. Effect of therapy on bronchial hyperresponsiveness in the long-term
management of asthma. Clin Allergy. 1988;18:165-176.
FULL TEXT
|
ISI
| PUBMED
24. Ignacio-Garcia JM, Gonzalez-Santos P. Asthma self-management education program by home monitoring of peak
expiratory flow. Am J Respir Crit Care Med. 1995;151:353-359.
ABSTRACT
25. Lahdensuo A, Haahtela T, Herrala J, et al. Randomized comparison of guided self-management and traditional treatment
of asthma over 1 year. BMJ. 1996;312:748-752.
FREE FULL TEXT
26. Leickly FE, Wade SL, Crain E, Kruszon-Moran D, Wright EC, Evans 3rd R. Self-reported adherence, management behavior, and barriers to care
after an emergency department visit by inner city children with asthma. Pediatrics. 1998;101:E8.
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