Metered-dose inhaler for asthma patients: knowledge and effects of a theoretical and practical guidance for pediatricians

OBJECTIVE

To evaluate the effect of a theoretical and practical guidance on knowledge of pediatricians regarding the use of metered dose inhalers with spacers. To identify major deficiencies, correct them and train these physicians on the correct use of the devices.

METHODS

Pediatricians who participated in a theoretical-practical program focusing on the use of inhaler devices answered a questionnaire with five questions about the use of these devices before and after the program. A comparison of the scores obtained in the pre- and post-training tests was performed by Wilcoxon test for related samples, and a significance level of 0.05 was adopted.

RESULTS

Twenty pediatricians performed pre- and post-training tests. The performance of pediatricians in the post-training test was significantly better than baseline (p<0.001).

CONCLUSION

A brief orientation program for pediatricians significantly improved their knowledge on the use of metered-dose inhalers with spacers, which may translate into an improvement in quality and quantity of prescriptions of these devices in clinical practice. The questions with higher rates of errors in the pre-training test were the questions about the waiting time between two sprays in successive applications and about the correct way to attach the inhaler to the spacer, both with high levels of success in the post-training test.

[Evaluation of the knowledge of health professionals at a pediatric hospital regarding the use of metered-dose inhalers]

OBJECTIVE

To evaluate health professionals working at a tertiary pediatric hospital in terms of their knowledge regarding the practical use of metered-dose inhalers.

METHODS

Practical and written tests on the use of metered-dose inhalers were applied to physicians, physical therapists, nurses and nursing assistants. A score from 0 to 10 was assigned to each evaluation, and median scores were calculated for each professional category. Questions with higher and lower correct values were identified, and a descriptive comparison was made regarding the performance of the various professional categories. Statistical analysis was performed using the Kruskal-Wallis method for comparison of medians. A sequential logistic multiple regression analysis was also performed.

RESULTS

A total of 30 resident physicians or interns in the pediatrics department, 23 attending physicians, 29 physical therapists, 33 nurses and 31 nursing assistants were evaluated. Resident physicians, physical therapists and attending physicians performed significantly better than did nurses and nursing assistants. Only resident physicians had a median score greater than 6.

CONCLUSIONS

The health professionals evaluated, particularly the nurses and nursing assistants, who are directly involved in the practical use of metered-dose inhalers, possess insufficient knowledge regarding the use of such inhalers.

The rejuvenated pressurised metered dose inhaler

The pressurised metered-dose inhaler (pMDI) has now been available for 50 years. Once regarded as an inefficient and difficult-to-use device, the technology has evolved significantly over the last few years, particularly since the introduction of novel formulations containing hydrofluoroalkane (HFA) propellants. Many modern HFA pMDIs deposit drug more efficiently in the lungs, impact less forcefully on the back of the throat and feel less cold than their chlorofluorocarbon pMDI counterparts. An improved understanding of technical factors makes it possible to design HFA pMDIs to have specific spray properties, particularly in terms of fine particle dose and spray velocity. Device technology has also progressed with the introduction of compact and convenient breath-actuated, breath-coordinated and velocity-modifying devices, which help patients to achieve a reliable lung dose. Although it faces competition from dry powder inhalers and possibly from novel soft-mist inhalers containing liquid formulations, the rejuvenated HFA pMDI is a device with a significant future for asthma, chronic obstructive pulmonary disease and wider treatment indications.

Key issues in inhalation therapy in children

In order to achieve asthma control it is essential that children receive the appropriate education and training pertaining to the management of their disease, are prescribed the correct medication according to severity, and most importantly, are prescribed the correct inhaler to ensure medication is deposited in their lungs. There are three major misconceptions which physicians and patients have regarding the use of inhalers in children. Firstly, that the nebulizer is more effective than a pressurised metered dose inhaler (pMDI) plus spacer in treating acute asthma in children. Secondly that using an inhaler correctly is easy, and lastly that correct use of the inhaler, once taught, persists over time. However, recent studies have shown that these conceptions are false. Firstly, comparable efficacy is achieved by treatment with inhaled corticosteroids or bronchodilators delivered through a nebulizer and a pMDI plus spacer, both when used to treat acute asthma and for maintenance therapy. Secondly, contrary to general opinion, using an inhaler correctly is difficult for children. Many children with asthma use their inhaler devices incorrectly, even after instruction for correct use of the inhaler. Thirdly, correct inhalation technique deteriorates over time; and inhalation instructions, therefore, should be given repeatedly to achieve and maintain correct inhalation technique in asthmatic children. The profile of the ideal inhaler comprises good drug deposition in the lower airways, deliverance of a consistent dose, being easy to teach and to use correctly, and being small in size and convenient to handle. It should also be multidose, require a low inspiratory airflow for activation, provide feedback to patients on correct use of the inhaler, be re-usable, have an appealing design and feel, and have a reliable dose counter which may help to monitor the patient's compliance. The Novolizer device, a new multidose dry powder inhaler (DPI), shows many of these characteristics making it potentially very suitable for children with asthma.