A randomized clinical trial comparing intranasal lidocaine and saline prior to gastroscopy

Intranasal lidocaine (LID) administration is a common treatment used to facilitate the passing of endoscopes and nasogastric tubes in horses. However, no research has supported its use in equine practice.

To compare patient reactivity and endoscope passage time between intranasal LID and intranasal saline prior to gastroscopy.

This blinded, randomized clinical trial included 25 horses presenting for gastroscopy. Following the administration of sedation and prior to gastroscopy, 10 ml of saline (CON) was administered intranasally to 12 horses in the control group, or 10 ml of 2% LID was administered intranasally to 13 horses in the LID group. The recorded data included signalment, location of scoping (field or hospital), sedation, grade of reactivity on a 6-point scale (0 for no reactivity up to five when the scope could not be passed), and time to passage from the nares to the cardia.

The time to reach the cardia in the CON group was 73 (35-183) seconds, and the time to reach the cardia in the LID group was 70 (45-210) seconds (p = 0.8). The number of horses with a reactivity grade less than or equal to 1 in the CON group was 75% (9/12) compared with 69% (9/13) in the LID group (p = 0.12).

This small study did not identify any significant benefit from administering intranasal LID prior to endoscope passage.