2008 Volume 101 Issue 12 Pages 925-930
The present study evaluated the incidence of otitis media with effusion (OME) after head and neck surgery in patients who had been free from OME preoperatively.
The subjects were 47 patients (90 ears; 22 males, 25 females; mean age 46.8 years; range 16-85 years) who had undergone head and neck surgery in our department. All ears had been free from middle ear diseases preoperatively. The operations were performed under general anesthesia in 42 cases, including 40 cases of nitrous oxide (N2O) anesthesia, and local anesthesia in 5 cases. Surgical sites were the middle ear in 2 cases, the nose in 9, the throat in 17, and the neck in 19. Otomicroscopic findings and tympanograms were evaluated three times; on the day before surgery, 1-2 days and 5-9 days after surgery.
At the first-postoperative inspection of the ear drums, middle ear effusion was observed in 6 ears (6.7%). Effusion disappeared in all ears at the second-postoperative inspection. Tympanograms, which were type A in all ears before surgery, changed to type B in one ear (1.1%), type C1 in 8 ears (8.9%) and type C2 in 9 ears (10.0%) at the first-postoperative testing. All ears returned to type A except in one ear (from type C2 to type C1) at the second-postoperative testing. The average of intratympanic pressure was -17.5±2.2daPa (mean±SEM) and -59.6±8.4daPa in preoperative and the first-postoperative testing, respectively (p<0.001). The second-postoperative pressure was -22.6±2.7daPa, which did not significantlly differ from the preoperative pressure.
In conclusion, we found that head and neck surgery might cause a decrease in intratympanic pressure. Temporary OME occurred in 6.7% ears and nitrous oxide (N2O) was used in all OME cases. We suppose that dysfunction of the eustachian tube was triggered by surgery and that N2O was related to the decrease in intratympanic pressure. Furthermore, continuation of negative intratympanic pressure promoted postoperative OME.
