Ultrasound Assessment of Difficult Airways Applying the Cormack-Lehane Scale: A Prospective, Observational, Interventional, Blind Study

Cristiana Laici1*, Amedeo Bianchini1, Sabrina Cavicchi2, Carla Serra3, Ada Dormi4 and Antonio Siniscalchi1

1Department of Organ Failures and Transplants, Anesthesia and Intensive Care Unit of Transplant, Azienda Ospedaliero-Universitaria di Bologna (IRCCS), Italy
2Department of Emergency, Anesthesia and Polyvalent Intensive Care Unit, Azienda Ospedaliero- Universitaria di Bologna (IRCCS), Italy
3Department of Organ Failures and Transplants, Interventional Ultrasound Unit, Azienda Ospedaliero- Universitaria di Bologna (IRCCS), Italy
4Department of Medical and Surgical Sciences, University of Bologna, Azienda Ospedaliero- Universitaria di Bologna (IRCCS), Italy

^*Correspondance to: Cristiana Laici 

 PDF  Full Text DOI: 10.25107/2474-1647.3266

Abstract

Background: A difficult airway cannot be effectively evaluated due to the lack of non-standardized clinical tests. The need to identify new tests with the aid ultrasound has recently been proposed as a useful, simple, non-invasive tool that can be performed in addition to the clinical method. The aim of this study is to assess the efficacy of ultrasound to identify a difficult airway according to objective, assessable parameters capable of predicting difficult intubation. Methods: This study was prospective, observational, monocentric, interventional and blind, conducted on 250 patients undergoing major abdominal elective surgery under general anesthesia. Preoperative clinical and ultrasound assessment were conducted bedside by two anesthesiologists different from the ones who conducted the intraoperative phase. At the end of the tracheal intubation, we differentiated the "easy" laryngoscopy (Cormack and Lehane [C-L] grades 1, 2a and 2b) from the "difficult" laryngoscopy (C-L grades 3a, 3b and 4) and compared it to previous ultrasound measurements. Results: The univariate and multivariate analysis showed that the ultrasound parameters able to predict the patients with easy (C-L grade ≤ 2b) and difficult (C-L grade ≥ 3) laryngoscopy was the thickness of the soft tissues anterior to the epiglottis in hyperextension of the head and protrusion of the tongue (STTep). Conclusion: Ultrasounds have been widely used as a diagnostic and a therapeutic tool, including to evaluate difficult airway and predict difficult intubation. Specifically, the ultrasound measurement of the STTep at 2.5 cm correlates with difficult laryngoscopy. Further studies are necessary to confirm this correlation.

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Cite the article

Laici C, Bianchini A, Cavicchi S, Serra C, Dormi A, Siniscalchi A. Ultrasound Assessment of Difficult Airways Applying the Cormack-Lehane Scale: A Prospective, Observational, Interventional, Blind Study. Clin Surg. 2021; 6: 3266..