Reversibility after inhaling salbutamol in different body postures in asthmatic children: a pilot study.
Respir Med. 2015 Apr;109(4):459-62. doi: 10.1016/j.rmed.2015.02.007.
- 1Department of Pediatrics, Medisch Spectrum Twente, P.O. Box 50 000, 7500 KA Enschede, The Netherlands. Electronic address: firstname.lastname@example.org.
- 2Medical School Twente, Medisch Spectrum Twente, P.O. Box 50 000, 7500 KA Enschede, The Netherlands; Department of Research Methodology, Measurement and Data Analysis, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. Electronic address: email@example.com.
- 3Department of Pulmonary Function, Medisch Spectrum Twente, P.O. Box 50 000, 7500 KA Enschede, The Netherlands. Electronic address: firstname.lastname@example.org.
- 4Department of Pediatrics, Medisch Spectrum Twente, P.O. Box 50 000, 7500 KA Enschede, The Netherlands. Electronic address: email@example.com.
Objectives: An important drawback of inhaled pulmonary medication is the impaction of particles at the sharp bend of the upper airway. A forward leaning body posture results in stretching the upper airway and may decrease impaction of particles and improve clinical effects.
Methods: 41 asthmatic children performed a spirometry with reversibility testing. They inhaled alternately in the standard or the forward leaning body posture 200 mcg salbutamol with an Autohaler®.
Results: Children who inhaled salbutamol in the forward leaning body posture showed a significantly higher mean FEV1 reversibility compared to the controls (10.2% vs. 4.1%, p: 0.019). They also showed a significantly more reversible MEF75 than the children in the standard body posture group (32.2% vs. 8.9%, p: 0.013).
Conclusions: Inhaling salbutamol in a forward leaning body posture resulted in a higher reversibility of FEV1 and MEF75 compared to the standard body posture in asthmatic children. This implicates that inhaling in a forward leaning body posture can improve the pulmonary effects of salbutamol probably due to a higher pulmonary deposition of salbutamol. This effect should be confirmed in a randomized controlled trial.
Inhaled bronchodilators are commonly used in asthmatic children. Impaction of inhaled medication in the sharp angle of the upper airway results in lower deposition at the target area (1,2). In children under the age of 12, inhalation of beclomethasone diproprionate via a breath actuated inhaler (BAI) resulted in 50-60% impaction in the oropharynx, as measured in a radio-labelling study (3). Brandao et al. demonstrated a faster recovery of lung function while inhaling nebulised bronchodilators in a forward leaning body posture compared to the standard body posture in young asthmatic adults (4). We hypothesized that inhalation of salbutamol with a stretched upper airway could improve the effect of salbutamol on lung function. The aim of this pilot study was to compare the reversibility of lung function during inhalation of 200 mcg salbutamol in a forward leaning body posture to the standard body posture in asthmatic children.
Clinically stable patients (6 till 16 years) with pediatrician diagnosed mild to moderate asthma, performed a (plannend) spirometry in Medisch Spectrum Twente, Enschede and participated in
this prospective pilot study. Long acting bronchodilater use 24 h before testing or short acting bronchodilator use 8 h before testing was not allowed.
Children performed spirometry by standard pulmonary function tests before and after the administration of 200 mcg salbutamol, administered with an Autohaler®. All pulmonary
function measurements, Forced Expiratory Volume in 1 s (FEV1), Forced Vital Capacity (FVC), Peak Expiratory Flow (PEF), Mean Expiratory Flow at 25% of vital capacity (MEF25) and Mean Expiratory Flow at 75% of vital capacity (MEF75), were performed in the same standard upright body posture.
Patients inhaled alternately in the standard upright body posture or in the alternative body posture: a forward leaning body posture with the neck extended (Fig. 1-3).
Fig 1: curved airway in standard posture
Fig 2: stretched airway in forward leaning postur
Fig 3: forward leaning body posture
The same investigator administered the inhaled medication to all children, this investigator did not perform the pulmonary function measurements. The pulmonary function technician was not blinded to the body posture during inhalation.
Because this was a pilot study no sample size calculation was performed. This study was conducted during 12 weeks between May 2013 and August 2013. Results were analysed after the inclusion of 41 children.
Our pilot study indicates that inhaling salbutamol in a forward leaning body posture results in a significantly higher reversibility of lung function expressed as FEV1 and MEF75 compared to inhaling in a forward leaning body posture. All results are shown in table 1.
Table 1: Change in pulmonary function after inhaling 200µgr salbutamol in different body postures.
|Standard body posture||Forward leaning body posture||Difference(95%CI)||P value|
|FEV1 reversibility||4.1 (7.4)||10.2 (8.5)||-0.111; -0.011||0.019|
|VC reversibility||0.8 (3.9)||2.2 (3.9)||-0.039 ; 0.010||0.241|
|PEF reversibility||9.4 (14.7)||11.1 (16.3)||-0.116 ; 0.083||0.740|
|MEF25 reversibility||9.9 (15.2)||18.3 (24.0)||-0.212 ; 0.045||0.194|
|MEF75 reversibility||8.9 (30.5)||32.2 (25.8)||-0.414 ; -0.052||0.013|
Data expressed as mean ± SD. FEV1: Forced Expiratory Volume in 1 second, FVC: Forced Vital Capacity, PEF: Peak Expiratory Flow, MEF25: Mean Expiratory Flow at 25% of vital capacity, MEF75: Mean Expiratory Flow at 75% of vital capacity.
This suggest that a forward leaning body posture can improve pulmonary effects of salbutamol, probably by a higher pulmonary deposition.
We observed a significant higher reversibility of the FEV1 and MEF75, but not of the PEF, VC and MEF25 in the forward leaning body posture, suggesting mainly the conductive airways profited of the forward leaning body posture.
A higher pulmonary deposition of inhaled medication can lead to a reduction in dose and consequently a reduction in side effects, which are not uncommon. Dubus et al. showed that approximately 60% of asthmatic children using beclomethasone diproprionate or budesonide reported local side effects such as coughing, hoarseness, dysphonia and oral candidiasis (5).
Because this was a pilot study without a randomised cross-over design, the effect of inhaling in a forward leaning body posture should be assessed in a randomized controlled trial with different doses of salbutamol, preferably radio-labeled.
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