Impaired sense of smell in patients with nasal surgery.

The aim of the study was to determine the incidence of olfactory disorders before and following nasal and paranasal sinus surgery. It was a prospective observational study. Over a 6-month period, all patients who had been listed for nasal and paranasal sinus surgery underwent preoperative and postoperative evaluation of their sense of smell. A questionnaire and the 'Smell Diskettes Test' were used to assess olfaction. One hundred and eighty-four patients were studied. Preoperatively, 19 patients (10.3%) had an impaired sense of smell (8.1% before septoplasty, 6.1% before rhinoplasty and 17.1% before endoscopic sinus surgery). Only 16 (84%) of these patients were aware of their impaired sense of smell. Following surgery, four patients (2.5%) who were normal preoperatively developed impaired olfaction on questioning, and this was supported by testing it. In the subgroup that had a septoplasty, no patient developed hyposmia compared to one patient (2.6%) after rhinoplasty and one patient (3%) after endoscopic sinus surgery. No patient developed anosmia. Preoperatively, 10.3% of patients had an altered sense of smell, making it desirable that this is documented in order to avoid postoperative claims that this was caused by surgery. It also helps to audit the results of surgery.