Evaluation of the efficacy of the 'nasal airflow-inducing manoeuvre' for smell rehabilitation in laryngectomees by means of the Sniffin' Sticks test

Abstract

Objective: To determine the efficacy of the nasal airflow-inducing manoeuvre (NAIM) as a method for olfactory rehabilitation in laryngectomees by the means of the Sniffin' Sticks test.

Study design: Prospective open interventional trial.

Setting: Tertiary academic hospital.

Participants: Thirty-seven patients after laryngectomy have been screened and 25 patients have been included into the study. The participant's sense of smell was tested with the Sniffin' Sticks test before and after learning the nasal airflow inducing manoeuvre. The individual level of threshold, discrimination and identification (TDI) was determined and the individual threshold, discrimination and identification score was used to classify the patients as being anosmic, hyposmic or normosmic.

Main outcome measures: The primary endpoint was the change of the threshold, discrimination and identification score before and after learning the nasal airflow inducing manoeuvre. The secondary endpoint was a change in the diagnostic group (normosmic, hyposmic and anosmic) after learning of the nasal airflow inducing manoeuvre.

Results: There was a statistically significant increase in the total threshold, discrimination and identification score (P < 0.001) and the three sub-scores (P ≤ 0.02) before and after the learning of the nasal airflow inducing manoeuvre. Patients gained seven points on average in the threshold, discrimination and identification score. Twenty of 25 patients showed an increase of five or more point in the threshold, discrimination and identification score. In the classification of the smell ability, 15 of 25 patients showed a change to a higher class (hyposmic to normosmic or from anosmic to hyposmic or normosmic).

Conclusion: The nasal airflow inducing manoeuvre is a method for the successful rehabilitation of the sense of smell in laryngectomees. The evaluation with the Sniffin' Sticks tests showed a clinically relevant increase of olfaction in 80% of patients. The teaching of the nasal airflow inducing manoeuvre should be included in post-laryngectomy rehabilitation programmes.