Pressure gradient and inspiratory times required for valve opening of various holding chambers.

This study was designed to determine whether infants generate sufficient inspiratory pressure gradient to open the unidirectional valve of various commercially available holding chambers, as well as the time required to reach this gradient. A prospective, cross-sectional study was performed of 80 healthy infants (aged 1-24 months) seen in the childcare outpatient clinic of a pediatric hospital, from October to December of 2007. Using the same inhalation technique recommended for treatment of respiratory diseases and asthma in this age group, four holding chambers were analyzed: Flumax Baby, AlergoChamber, LuftChamber, and ACE (n = 20 infants per analysis group). The variables measured were gradient of inspiratory pressure and time for the valve to open. The holding chambers did not differ in gradient of inspiratory pressure (p = 0.382) or time to open the valve (p = 0.199). Fifteen of 80 infants were not able to generate sufficient inspiratory pressure to open the valve (1 using AlergoChamber, 5 using Flumax Baby, 6 using ACE, and 3 using LuftChamber), with no significant differences between devices. The holding chambers were similar regarding pressure gradient and time required to open the valve. The fact that 19% of the sample was unable to open the valve suggests that it would be useful to determine the ability of small children (<24 months of age) to use holding chambers before prescribing them.

Determination of parameters related to nasal inspiratory pressures in children utilizing valved-holding chambers (valved spacers).

OBJECTIVE: The administration of medication by the nasal route using valved spacers, may be an alternative for the concomitant treatment of allergic rhinitis and asthma. The aim of this study was to determine if children are capable, in using a spacer and face mask, of opening the inspiratory valve using only nasal inhalation. METHODS: Prospective cross-sectional. The study included 85 children aged 4-9 years. Four types of valved spacers connected to a digital vacuum manometer were evaluated. The patients were prompted to inhale through their nose and the pressure reached in the first curve, maximal peak and time between the start of the inspiratory action and the first effective inspiration (opening of the valve) were determined. The results were compared with factors such as age, weight, BMI, gender, and presence of rhinitis or asthma. RESULTS: In two of the spacers, the valve opened in 98.8% of the tests with nasal inspiration only. The spacer ACE holding chamber showed initial and maximal inspiratory pressures that were significantly greater than with the others (p<0.001). No correlation was observed between the parameters examined for each spacer and the patient variables considered. CONCLUSION: The results suggest that children 4-9 years old are able to open the spacer valve with only nasal inspiration. The spacer ACE holding chamber was shown to be significantly more effective than the others tested. Studies that demonstrate that air inspired nasally reaches the lungs effectively are necessary so that this airway can be utilized for the administration of therapeutic agents.