Evaluation of self-percussion during postural drainage using the forced expiration technique

Abstract

The forced expiration technique (FET) is commonly used in conjunction with self-percussion of the chest wall and thoracic expansion breathing exercises while lying in appropriate gravity assisted positions. The efficacy of percussion in this context has not been studied, so we have compared the effects of self postural drainage with and without self-percussion.

Sixteen adolescent and adult cystic fibrosis patients were studied over 4 days. On 2 days treatment included thoracic expansion exercises and self-percussion interspersed with the FET (treatment P). On the other 2 days self-percussion was omitted (treatment A). Treatment days were randomised. Recordings were made of sputum weight and lung function.

On the days of treatment A the mean daily sputum weight in treatment periods was 57.1 gm, and with treatment P 52.0 gm. The difference between these results was not statistically significant. Comparing the non-treatment periods in each 24 h, there was no significant difference in weight of sputum produced. Comparing FEV₁ (forced expiratory volume in one second) and FVC (forced vital capacity) before treatment each day there was an improvement following both treatment days A and P.

Although self-percussion showed no advantage in weight of sputum produced, many patients will continue doing it if they feel it is beneficial. Unless studies prove satisfactorily that it is detrimental, there is no reason to stop them doing percussion. Those who dislike doing percussion or find it tiring can be advised to omit percussion provided breathing exercises and FET are carried out effectively.