Cervical auscultation using Doppler ultrasound for swallows of different consistencies by young and older healthy adults

Abstract

Aim: The use of a stethoscope for cervical auscultation (CA) has been reported to be useful in detecting potential swallowing ailments. Nevertheless, stethoscopic CA suffers several constraints including poor signal-to-noise ratio. The current study examined the signal characteristics of CA using Doppler ultrasound obtained when swallowing liquids of different consistencies by both older and younger healthy individuals. Method: Thirty healthy younger and older adults participated in the study. Doppler ultrasound CA was carried out when they swallowed 5-mL liquids of different consistencies according to IDDSI levels 0–4: (1) thin, (2) slightly thick, (3) mildly thick, (4) moderately thick, and (5) extremely thick using a portable Doppler ultrasound device. Parameters including the duration of swallow CA signal (T), time to onset of the second peak (TP2), and the intensity and frequency of the first and second peaks (IP1, IP2, FP1, FP2) were obtained from the ultrasound CA signals. Results: From the ultrasound CA signals of swallowing, durational measures including T and TP2 generally increased with age but not bolus consistency. However, intensity and frequency measures appeared to be similar between young and older healthy adults, even when swallowing liquids of different consistencies. Conclusions: Doppler ultrasound CA signals revealed that older adults were associated with a longer swallowing duration than the younger counterparts, but not across bolus consistencies. Frequency and intensity measures appeared to be insensitive to the effects of age and bolus consistency. The findings support that ultrasound CA could be used to clinically evaluate swallow proficiency.