Relationship of peak flow rate and peak velocity time during after voluntary coughing

The differences in phonation between men and women are thought to occur from anatomical differences in the larynx. However, it is not known if there are any differences in cough dynamics between the sexes. We investigated this by asking 100 healthy, non-smoking adults (50 male) to perform a voluntary cough into a tussometer. Each volunteer coughed at four different lung volumes, ranging from total lung capacity to functional residual capacity. There was a positive correlation between peak velocity time and cough peak flow rate in both males (r 0.73, P 0.001) and females (r 0.78, P 0.001). Multiple regression analysis showed that height (P 0.05) and sex (P 0.001) were significant determinants of the relationship between peak flow rate and peak velocity time. In a height-matched subgroup, sex differences remained significant (P 0.05). This may be related to anatomical differences in laryngeal structure and may have implications when using tussometry to assess laryngeal function. (Br. J. Anaesth. 1995; 74: 714–716)