The effect of oral topical anesthesia on the characteristics of voice

Although oral topical anesthesia is used routinely before rigid laryngeal endoscopy, no study has determined whether oral topical anesthesia changes voice quality. Our goal was to determine the effects of topical anesthesia on voice.

Prospective cohort study.

Adult patients presenting to a laryngology practice who required rigid laryngeal endoscopy as part of the routine clinical visit were eligible for the study. Voices were recorded before and after oral topical benzocaine (14%)/butamben (2%)/tetracaine (2%) (ie, cetacaine) spray. Consensus auditory perceptual evaluation of voice (CAPE-V) protocol was used for the voice recordings and was the primary outcome measure. Recordings were presented randomly to two blinded speech-language pathologists specialized in voice. Secondary outcome measures were fundamental frequency (F0), jitter, shimmer, and noise-to-harmonics ratio (N/H) on sustained /i/ and speaking F0.

One hundred two patients participated in the study. There was no significant difference in CAPE-V measurements before and after topical anesthesia for all six attributes: overall severity (P = 0.145), roughness (P = 0.214), breathiness (P = 0.761), strain (P = 0.053), pitch (P = 0.301), and loudness (P = 0.320). There was no significant difference in jitter (P = 0.315), shimmer (P = 0.942), N/H (P = 0.128), and speaking F0 (P = 0.320). F0 /i/ decreased by a mean of 4.8Hz, which was statistically significant (P = 0.003), but probably not clinically significant.

There was no clinically significant voice change after oral topical anesthesia.