Topical Anesthesia and Olfactory Capability: A Pilot Study

Area of Science:

• Otolaryngology
• Neuroscience
• Anesthesiology

Background:

• Topical anesthesia (TA) is commonly used for patient comfort during nasal endoscopy.
• The duration of TA's effect on olfactory function is not well-established, impacting the timing of olfactory testing.
• Accurate olfactory assessment requires understanding when TA's effects subside.

Purpose of the Study:

• To determine the time course of olfactory capability recovery after intranasal TA administration in healthy volunteers.
• To establish the optimal window for olfactory testing post-TA application.

Main Methods:

• A prospective, single-center pilot study involving 30 healthy volunteers.
• Olfactory function was assessed using the University of Pennsylvania Smell Identification Test (UPSIT) at baseline and at three time points after TA administration: immediately (T0), 10 minutes (T+10), and 30 minutes (T+30).
• Statistical analysis included paired t-tests to compare UPSIT scores across time points.

Main Results:

• Immediately after TA administration (T0), UPSIT scores were significantly lower than baseline, indicating impaired olfactory function.
• Olfactory function, as measured by UPSIT scores, significantly recovered by the 10-minute mark (T+10) and showed no significant difference from baseline.
• UPSIT scores at 30 minutes (T+30) also showed no significant difference from baseline, confirming olfactory recovery.

Conclusions:

• Intranasal topical anesthesia significantly impairs olfactory function immediately after administration.
• Olfactory capability is fully recovered by 10 minutes post-TA application, allowing for accurate olfactory testing.
• These findings provide crucial timing guidance for olfactory assessments following nasal procedures involving TA.