Stephen C Allen1, Ahmed Khattab. 1. Medicine and Geriatrics, Royal Bournemouth Hospital, Castle Lane East, Bournemouth BH7 7DW, UK. stephen.allen@rbch.nhs.uk
Abstract
BACKGROUND: in a previous study, we showed that the ability to detect a rise in airflow resistance at rest was reduced in some non-asthmatic subjects in old age. OBJECTIVE: to determine whether airflow resistance detection is attenuated in elderly subjects with asthma. METHODS: we studied 60 adult subjects with stable asthma (age range 20-88). Progressive external airflow resistance loading was used to measure the inspiratory load detection threshold (LDT) during tidal breathing at rest. RESULTS: the mean inspiratory LDT was 5.57 (4.33 SD) kPa.s/l in the 20-64 age group (n=32) and 15.6 (10.1 SD) kPa.s/l in those aged 65 and above (n=28) (P<0.0001). The inspiratory LDT was significantly correlated with age (r=0.5246, P<0.00008), mainly due to the effect of higher LDTs in about half of the subjects above the age of 65 years. Expiratory LDT values and correlations were very similar to inspiratory values. CONCLUSIONS: the threshold for detecting external resistive loads during tidal breathing rises in old age in some, but not all, asthmatic patients as was observed in non-asthmatic subjects. The finding has implications for treatment guidelines because some elderly subjects are likely to have reduced awareness of worsening airflow obstruction, and consequently delay their use of rescue treatments.
BACKGROUND: in a previous study, we showed that the ability to detect a rise in airflow resistance at rest was reduced in some non-asthmatic subjects in old age. OBJECTIVE: to determine whether airflow resistance detection is attenuated in elderly subjects with asthma. METHODS: we studied 60 adult subjects with stable asthma (age range 20-88). Progressive external airflow resistance loading was used to measure the inspiratory load detection threshold (LDT) during tidal breathing at rest. RESULTS: the mean inspiratory LDT was 5.57 (4.33 SD) kPa.s/l in the 20-64 age group (n=32) and 15.6 (10.1 SD) kPa.s/l in those aged 65 and above (n=28) (P<0.0001). The inspiratory LDT was significantly correlated with age (r=0.5246, P<0.00008), mainly due to the effect of higher LDTs in about half of the subjects above the age of 65 years. Expiratory LDT values and correlations were very similar to inspiratory values. CONCLUSIONS: the threshold for detecting external resistive loads during tidal breathing rises in old age in some, but not all, asthmatic patients as was observed in non-asthmatic subjects. The finding has implications for treatment guidelines because some elderly subjects are likely to have reduced awareness of worsening airflow obstruction, and consequently delay their use of rescue treatments.
Authors: Gwen S Skloot; Paula J Busse; Sidney S Braman; Elizabeth J Kovacs; Anne E Dixon; Carlos A Vaz Fragoso; Nicola Scichilone; Y S Prakash; Christina M Pabelick; Sameer K Mathur; Nicola A Hanania; Wendy C Moore; Peter G Gibson; Susan Zieman; Betina B Ragless Journal: Ann Am Thorac Soc Date: 2016-11
Authors: Carl R O'Donnell; Richard M Schwartzstein; Robert W Lansing; Tegan Guilfoyle; Daniel Elkin; Robert B Banzett Journal: BMC Pulm Med Date: 2013-04-27 Impact factor: 3.317