A study in which children and their parents were observed shows that errors in inhalation technique are frequent.

Inhalation therapy has become the mainstay of treatment for most pediatric pulmonary diseases. Although the idea of delivering therapeutic agents directly to the site of action is appealing, achieving that goal is not as easy as it sounds. Patients, physicians, RTs, and nurses can take advantage of a wide variety of aerosol delivery systems. These include nebulizers (jet and ultrasonic), metered-dose inhalers (MDIs), and dry-powder inhalers (DPIs).¹ Although delivery systems may share common principles of operation, their inhalation techniques and maintenance procedures differ. Errors in inhalation technique may decrease intrapulmonary drug deposition, leading to a decrease in therapeutic response and/or an increased incidence of side effects.

Optimal delivery of inhaled drugs requires matching patient characteristics with a delivery system. If nebulizers are used, a loose fit between the mask and the face dramatically decreases drug delivery.² Ultrasonic nebulizers are not suitable for the delivery of corticosteroids.³ The use of a low amount of diluent will create a low drug output in nebulizers with high dead volumes.⁴

Mistakes that are commonly seen in MDI use can decrease drug delivery; these include failing to uncap the MDI, not shaking the canister, positioning the canister with the stem facing up, and the lack of tight fit between the face and the spacer/holding chamber mask.⁵ Moreover, when a holding chamber is used, the lack of a good face seal is likely to make the patient unable to open the valve. An incorrect activation, expiration inside the system, and achieving a low inspiratory flow will also lead to a significant decrease in the drug output of a DPI.^6,7

In Buenos Aires, Argentina, no local data were available regarding physicians’ practices and patients’ performance of inhalation techniques using different aerosol-delivery systems. Therefore, at the Hospital de Niños Ricardo Gutiérrez, we conducted a prospective clinical study intended to describe prescription patterns and patient knowledge of the aerosol-delivery devices being used to treat pulmonary disease. We also wanted to identify those errors that could decrease intrapulmonary drug deposition.

We interviewed 150 children and their parents sequentially after outpatient encounters at our hospital. Patients were eligible if they were seen for any respiratory condition requiring the use of aerosolized drugs. None of the patients or families refused to participate. The study was conducted in April and May 2001 at our urban, university-associated, tertiary care children’s hospital. Each interview consisted of the administration of a structured questionnaire by an investigator. The questionnaire, administered to parents, covered parents’ knowledge about the disease, the utility of the prescribed treatment, and cleaning techniques. Parents and children were interviewed (when children were able to be interviewed). In addition to the questionnaire, a hands-on evaluation of inhalation technique (for the system being used by the patient) was performed. Those patients using DPIs also had their peak inspiratory flow checked. Mistakes that could dramatically affect intrapulmonary drug deposition as predetermined in the study’s design were deemed relevant.

Results
Interviewed patients had a mean age of 4.5 years (range: 3 months to 18 years). Ninety-four (63%) were males and 56 (37%) were females. The diagnoses indicated by the interviewed patients were bronchial obstruction (67%), chronic pulmonary disease other than asthma (6%), other diagnosis (9%), and unknown to the patient (18%). The purpose of the drugs being used (for example, controllers versus relievers) was unknown to 78 patients (52%). A written treatment plan had been given to 73% of patients.

Nebulizers were being used by 124 patients (85%). Their mean age was 4 years (range: 3 months to 18 years). MDIs were being used by 72 patients (48%). Their mean age was 5 years (range, 6 months to 17 years). DPIs were being used by 19 patients (13%); they had a mean age of 11 years (range: 6 to 15 years). Two aerosol-delivery systems were used by 59 patients (39%), and 3 patients (2%) used all three systems.

Only 17 (14%) of the patients using nebulizers had been specifically advised by their health care providers to buy an ultrasonic nebulizer (2%) or a jet nebulizer (14%). Patients decided on their own whether to use an ultrasonic (39%) or jet (61%) nebulizer. Only four patients used a mouthpiece, and 72 of the 76 patients more than 4 years old who were able to use mouthpieces were using face masks instead. Parents of 20 patients (16%) recalled giving nebulization treatments with the mask not well fitted to the face. Nebulizer treatments were received in the supine position by 42 patients (34%). Of the 18 patients who regularly used a pacifier, five (28%) were using it during nebulizer treatment.

Cleaning instructions were given to 24% of patients. The practices recommended were rinsing with water (48%), vinegar (21%), alcohol (17%), bleach (10%), or povidone-iodine (4%). The patients who did not receive any cleaning instructions used either water (52%) or vinegar (24%). Another 24% of patients who did not receive specific information did not clean the nebulizer at all. Eighteen percent of patients had nebulizer errors that were counted as relevant (see figure).

Spacers/holding chambers were used by 62 (86%) of the patients who used MDIs. A two-valve space was used by 43 patients (69%), a one-valve spacer by 15 patients (24%), and a valveless spacer by 4 (7%). Twenty-eight patients (44%) did not clean the spacer. The remaining 56% cleaned it with detergent (27%) or used other methods (29%), including water, alcohol, sodium bicarbonate, and a dry cloth. Seventy-seven percent of the children received a practical demonstration of inhalation technique during the clinic visit when inhalation therapy was first prescribed. Only 21 patients (32%) had their technique checked regularly during subsequent visits.

Inhalation technique was evaluated by the interviewers using placebo inhalers. Of 72 patients, 2 (3%) did not uncap the MDI, 2 (3%) positioned the canister with the valve stem facing up, and 14 (19%) did not shake the canister before actuation. Those mistakes, along with the lack of good seal between face and mask, were considered to affect drug output significantly. All of the nine patients who used the MDI without a spacer had faulty inhalation technique. Twenty-six patients (36%) were found to make relevant mistakes when using an MDI, with or without a spacer/holding chamber.

The 19 patients being treated with DPIs used two different delivery systems. Eighteen patients (95%) received theoretical instruction in operating the DPI, and 16 (84%) also received a practical demonstration. Twenty-six percent of patients had their inhalation technique reviewed during some subsequent encounters or at every visit. Nine DPI users (47%) generated an inspiratory flow of less than 40 L/min. During the hands-on demonstration, we found that 26% of the patients did not activate their DPIs properly, and 21% exhaled into the delivery system. Eleven patients (58%) failed to rinse their mouths after inhaling the medication. In all, 11 DPI users (58%) made relevant mistakes.

Conclusion
Our findings are in agreement with previously published data from studies^8-10 performed worldwide. Several errors in inhalation technique were observed. Those mistakes were attributable to lack of education among both parents and physicians. We speculate that this could be due either to lack of knowledge or to the short duration of health care encounters. Inhalation therapy is fundamental in the treatment of pediatric lung disease. The results of this survey underscore the need for continuous education, not only for patients but also for health care providers. Based on our findings, we recommend that inhalation technique be reassessed at each encounter and that cleaning techniques be taught to parents/patients. Parents should also be provided with general information about the patient's disease and treatment objectives, along with written information regarding inhalation technique and maintenance procedures for each device in use. Implementation of educational intervention is essential to improvement in the results documented by this survey.

Carlos Kofman, MD, is staff medical doctor, Centro Respiratorio, Hospital de Niños Ricardo Gutiérrez, Buenos Aires, Argentina. Ariel Berlinski, MD, is senior house staff, Department of Pediatrics, Long Island College Hospital, Brooklyn, NY. Silvina Zaragoza, MD, is staff medical doctor at the Hospital de Niños Ricardo Gutiérrez. Alejandro Teper, MD, is chief, Centro Respiratorio, Hospital de Niños Ricardo Gutiérrez.

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