Otic drops used to clear a blocked grommet: an in vitro prospective randomized controlled study with blinded assessment.

Clinicians often prescribe otic drops anecdotally to try and clear grommets blocked with blood. We carried out an in vitro double-blind randomized controlled study comparing the efficacy of sodium bicarbonate, Locorten Vioform and olive oil drops in clearing Shah grommets placed in 'artificial ears' and blocked with blood in a standardized fashion. There were 33 grommets in each group, and drops were inserted three times a day for 7 days. Olive oil drops cleared 17 of 33 (51.51%), Locorten Vioform cleared one of 33 (3%) and sodium bicarbonate cleared zero of 33 (0%) blocked grommets. Statistical comparison between pairs indicates that olive oil was significantly better than both Locorten Vioform (P < 0.001) and sodium bicarbonate drops (P < 0.001) at clearing grommets blocked with blood.