Pre-operative transnasal endoscopy as a predictor of difficult airway: A prospective cohort study

Eur J Anaesthesiol. 2020 Feb;37(2):98-104. doi: 10.1097/EJA.0000000000001127.


Background: Consequences of failed endotracheal intubation can be catastrophic and predicting difficulty is therefore a critical issue. There is no consensus on the best way to predict difficulty.

Objective: To evaluate the role of transnasal flexible endoscopic laryngoscopy (TFEL), a minimally invasive procedure, in the prediction of difficult intubation.

Design: Prospective cohort study.

Setting: San Raffaele Hospital, Milan, a tertiary university hospital.

Patients: One hundred and sixty nine adults scheduled for elective ear, nose and throat surgery under general anaesthesia with pre-operative TFEL.

Intervention: In addition to routine pre-operative evaluation by an anaesthesiologist, glottis exposure during TFEL was assessed with a scoring system similar to the modified Cormack-Lehane (MCL).

Main outcome measures: The extent to which TFEL improves the prediction of difficult direct laryngoscopy, measured with the MCL score, and of difficult intubation, measured with the intubation difficulty scale score.

Results: When added to bedside evaluation, TFEL performed during tongue protrusion significantly (P = 0.005) improved the prediction of MCL. The area under the receiver operating characteristics curve was 0.75 [95% confidence interval (CI) 0.67 to 0.83] vs. 0.65 (95% CI 0.58 to 0.74). For the intubation difficulty scale (P = 0.049), the area under the receiver operating characteristics curve was 0.70 (95% CI 0.61 to 0.80) vs. 0.66 (95% CI 0.58 to 0.74).

Conclusion: TFEL is a useful tool in predicting difficult intubation, improving predictability of routine bedside evaluation.

Trial registration: identifier: NCT02671877.

MeSH terms

  • Adult
  • Anesthesia, General
  • Glottis
  • Humans
  • Intubation, Intratracheal*
  • Laryngoscopy*
  • Prospective Studies

Associated data