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318 Ji et al. | Journal of Clinical and Translational Research 2023; 9(5): 317-321
direct deposit of drugs into the airway and, therefore, reduces the the usual bronchodilator treatment could worsen the underlying
amount of medication needed, minimizing the systemic effect of respiratory pathology.
the drugs [5].
Metered dose inhalers (MDIs) present some advantages 2.3. Sample size calculation
compared with other devices: They require no threshold inspiratory To achieve a statistical power of 80% and a significance level
flow to trigger the release of the active compound, and they are of a two-tailed P < 0.05, 45 patients were necessary for the study
cheap [6-8]. However, their use requires dexterity to complete to detect a 5% of difference. A loss of 10% was anticipated,
the required sequential steps to achieve a correct inhalation of the rendering a sample of 50 participants.
medication; in particular, they require coordination between the
pulsation of the cartridge and the inhalation. Incorrect completion 2.4. Study interventions
of one or more steps in using an MDI can substantially reduce Before the BDR test, participants were asked to interrupt their
the administrated medication delivery and consequently its usual bronchodilator medication according to standard washout
effectiveness and safety. Numerous studies have demonstrated that recommendations [13]. On the first visit, after checking that the
50 – 100% of patients do not use their inhaler devices correctly patient had followed the washout instructions, baseline spirometry
[9]. To overcome this limitation, MDIs are frequently used with was performed [13]. This was followed by the inhalation of
add-on devices referred to as inhalation chambers (“chambers,” in 400 µg of salbutamol MDI through the Aerochamber Plus Flow-
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the context of inhalation devices) [10]. Chambers act as reservoirs Vu chamber. A postbronchodilator spirometry was performed
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and reduce the speed at which the aerosol enters the mouth. This 15 min later. Patients then completed the Feeling of Satisfaction
makes using the inhaler easier and helps ensure that more of the with Inhaler (FSI-10) questionnaire, and washing-out instructions
medication reaches the lungs [11]. were given for the next visit. Two days later, a similar BDR test
Performing spirometry before and after the inhalation of was performed, this time using the Dosivent chamber.
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bronchodilators (bronchodilator response [BDR] testing) is in The main outcomes were changed in FEV1 and FVC, measured
diagnosing asthma and COPD [12,13]. In most laboratories, the as absolute value and percentage (i.e., [postbronchodilator FEV1
bronchodilator drug (usually salbutamol/albuterol) is administered or FVC – prebronchodilator FEV1 or FVC]/prebronchodilator
through a chamber. The Dosivent inhalation chamber is FEV1 or FVC).
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designed to optimize the delivery of inhaled bronchodilators and The secondary outcome was the difference in FSI-10 score
corticosteroids in the treatment of respiratory diseases. between the two chambers.
This study was conducted to compare the efficacy, as measured Other variables such as demographic data, underlying lung
by changes in forced expiratory volume in the first second (FEV1) disease, and adverse effects were collected from medical records
and forced vital capacity (FVC), of salbutamol inhaled with the and the anamnesis on the day of the bronchodilator tests.
Dosivent chamber versus the widely used Aerochamber Plus
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Flow-Vu in patients with a positive BDR, as Dosivent is a 2.5. Statistical analysis
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previously unstudied chamber.
Quantitative variables are described as mean and standard
2. Materials and Methods deviation (SD) or should the normality assumption not hold,
median, and interquartile range (IQR). The Friedman test was
2.1. Design used for two-tailed statistical comparisons of between-groups
We conducted a non-randomized, open-label, crossover- changes in FEV1, FVC, and FSI-10 questionnaire score. To
controlled, and clinical trial in 50 patients with a previous evaluate the agreement between BDR with both chambers, the
positive BDR. The protocol was approved by the Drug Research intraclass correlation coefficient and Bland–Altman graphic
Ethics Committee of the Gregorio Marañon General University analysis were performed. For the latter, the ordinates were the
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Hospital (code 03/2022) and registered with registration number difference between the Dosivent and Aerochamber Plus Flow-
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NCT05821868. All participants provided written informed consent Vu . Statistical significance was established at P < 0.05 for all
before any study procedure. During the study, the principles of the comparisons. Stata version 15 was used to generate the Bland–
Declaration of Helsinki and the current standards of Good Clinical Altman plots. All other analyses were performed with SPSS
Practice were followed. version 26.
2.2. Study population 3. Results
Patients over 18 years of age were included who attended Fifty-six patients were invited to participate in the study.
our center for a bronchodilator test, gave a positive result in this Of these, 50 provided written informed consent and were
test, and provided written informed consent for participation in included in the study. No participant dropped out of the study
this study. Patients were excluded if Grade A quality spirometry (Figure 1).
was not obtained according to the classification in current Twenty-five (50%) of the participants were men. The mean
guidelines [13] and, in the opinion of the investigator, performing age was 58 (SD 18) years, the mean height was 1.64 m (0.1), the
a bronchodilator test could pose a risk to the patient or interrupting mean weight was 75.1 kg (17.5), and the mean body mass index
DOI: http://dx.doi.org/10.18053/jctres.09.202305.23-00081