title: Amount of airflow required for olfactory perception in laryngectomees: a prospective interventional study.
abstract: OBJECTIVE
  To determine minimum airflow rate required for olfactory stimulation in successfully rehabilitated laryngectomised patients after learning the polite yawning technique (PYT) and to confirm the hypothesis that sense of smell is rehabilitated once the nasal airflow is re-established.
  
  
  METHODS
  Prospective open interventional trial.
  
  
  METHODS
  Tertiary academic hospital.
  
  
  METHODS
  The study population comprised 100 laryngectomised patients. The control group consisted of 100 non-laryngectomised patients of similar age and sex. Rhinomanometry was used to measure air flow in the right and left nostrils, respectively, while the Smell Diskettes Olfaction test (SDOT) was used to test each individual's sense of smell.
  
  
  METHODS
  The primary endpoint was increasing the airflow, while the secondary endpoint was improvement in the Smell Diskettes Olfaction test score after learning the polite yawning technique.
  
  
  RESULTS
  The difference in the Smell Diskettes Olfaction test results before and after introducing the polite yawning technique was statistically significant (F = 53.077; P < 0.001). The number of accurately identified odours increased with each measurement. There was a significant difference among rhinomanometric measurements of airflow through the right (F = 65.002; P < 0.001) and left nostrils (F = 75.465; P < 0.001). Nasal airflow improved with each measurement. The minimum airflow required for olfactory stimulation in successfully rehabilitated patients was approximately 60 cm(3) /s. The control group had considerably better airflow in both nostrils than the laryngectomised group. The difference between the total number of rehabilitated (normosmic) patients (48%) in the laringectomised group and normosmic participants (56%) in the control group (z = 1.132; P = 0.129) was not statistically significant.
  
  
  CONCLUSIONS
  The number of odours identified by laryngectomised patients increased with the volume of nasal airflow. The number of patients with rehabilitated olfactory function approximated the percentage of normosmic individuals in the non-laryngectomised population. These findings confirm the hypothesis that sense of smell is rehabilitated once the nasal airflow is re-established.
authors.affiliation: Clinic of Otorhinolaryngology, Head and Neck Surgery, University Hospital Rijeka, Rijeka, Croatia. dubravko_manestar@net.hr
authors.forename: D
authors.initials: D
authors.lastname: Manestar
authors.forename: R
authors.initials: R
authors.lastname: Tićac
authors.forename: S
authors.initials: S
authors.lastname: Maričić
authors.forename: G
authors.initials: G
authors.lastname: Malvić
authors.forename: D
authors.initials: D
authors.lastname: Čorak
authors.forename: M
authors.initials: M
authors.lastname: Marjanović Kavanagh
authors.forename: D
authors.initials: D
authors.lastname: Prgomet
authors.forename: R
authors.initials: R
authors.lastname: Starčević
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000403:Airway Resistance; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007825:Laryngectomy / Q000009:adverse effects* / Q000534:rehabilitation; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D009297:Nasal Mucosa / Q000503:physiopathology; D000857:Olfaction Disorders / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D011312:Pressure; D011446:Prospective Studies; D025363:Rhinomanometry / Q000379:methods*; D012903:Smell / Q000502:physiology*; D013997:Time Factors; D055815:Young Adult