Are regional anesthetics less likely to result in PONV in this patient?
Despite the elimination of general anesthesia, the risk of PONV is only somewhat less likely due to many reasons. Firstly, this patient is quite anxious; anxiety probably has a major role in nausea and vomiting. Additionally, caloric effects of injection of local anesthesia close to the vestibular system may stimulate the vestibular organ. Surgical suction may also induce caloric effects since passage of air may also lower temperature in the middle ear. Consequently, the vestibular system may be stimulated.
Manipulation of the ossicles results in vertigo in those patients who undergo ossiculoplasty and, as a result, PONV.
Finally, diffusion of local anesthesia through the round window membrane also contributes to PONV. Different local anesthetics diffuse at different rates and there may be different degrees of PONV depending upon the local anesthetic involved.