Copyright ©ERS Journals Ltd 2004 doi: 10.1183/09031936.04.00126904
The use of computer-animation programs during spirometry in preschool childrenPortex Unit of Anaesthesia, Intensive Therapy and Respiratory Medicine, Institute of Child Health, London, UK To the Editor: We read with interest the paper by Gracchi et al. 1 describing the use of computer-animation programs as a device to improve reproducibility in acquiring forced expiratory manoeuvres in 48-yr-olds. The study was simple and well designed but the possibility both that the computer-animation programs were not used to their full potential and that the European Respiratory Society "adult" reproducibility criteria are too strict for preschool children must be raised 2, 3. While we agree that the use of computer-animation incentive programs offers little advantage in the 68-yr-old group, younger children cannot always understand, process and carry out multistep tasks. In such children, using a combination of the computer-animation programs will allow the production of a prolonged forceful expiration to be broken down into smaller steps. We find starting with the candles, to achieve maximal peak flow, and then progressing to the balloons or bowling alley games (prolonging the forced expiration) with individualised target modification provides maximum encouragement for each child according to their ability and lung function. Individualised target modification is necessary as the animations are preset at a target of 120% predicted for both peak expiratory flow and forced vital capacity, a target that is only appropriate if based on suitable reference data for that age group. Any underestimation of predicted values (which, given the paucity of data from healthy 48-yr-olds, is quite likely to occur) will mean that the child reaches the animation target before they have truly reached their maximum, thereby losing the incentive to try any harder as they will not be able to see any improvement in their performance. Likewise, on some occasions it may be appropriate to reduce the target % initially in order to encourage the younger children or those with poor coordination to aim for a target that is achievable, thereby encouraging them to try harder next time, and to prevent them giving up. When comparing the proportion of children in the study by Gracchi et al. 1 who were able to achieve certain reproducibility criteria under the different measurement conditions it is important to note the following: 1) none of the observed differences were significant; 2) most of the children produced forced expiratory parameters within <0.1 L, rather than within 5% of each other, the former equating to a reproducibility of between 610% in most cases; and 3) small numbers in some subgroups meant that an 8.3% difference in "success rate" equates to a difference in performance of a single child. In conclusion, while we agree that when using the protocol described in this study there is minimal evidence of improved reproducibility, we believe that there is a role in the younger age group for these computer animation incentive programs provided they are used to their full capabilities. We therefore suggest that, before the use of such incentives is dismissed out of hand, further work should be undertaken to clarify these issues, having first ascertained appropriate quality control criteria for spirometry in very young children. Guidelines regarding the latter are currently being developed by an American Thoracic Society/European Respiratory Society Task Force as part of an initiative on lung function testing in preschool children. References
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||