Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Apr 4;17(1):55.
doi: 10.1186/s12871-017-0346-y.

Neck circumference to inter-incisor gap ratio: a new predictor of difficult laryngoscopy in cervical spondylosis patients

Yong-Zheng Han  1 , Yang Tian  1 , Mao Xu  2 , Cheng Ni  1 , Min Li  1 , Jun Wang  1 , Xiang-Yang Guo  1
Affiliations

Neck circumference to inter-incisor gap ratio: a new predictor of difficult laryngoscopy in cervical spondylosis patients

Yong-Zheng Han et al. BMC Anesthesiol. .

Abstract

Background: Preoperative airway assessment help anticipate a difficult airway. We hypothesized that a close association existed between difficult laryngoscopy and the neck circumference/inter-incisor gap ratio (RNIIG). Our aim was to determine its utility in predicting difficult laryngoscopy in cervical spondylosis patients.

Methods: Two hundred thirteen consecutive patients, aged 20-70 years, scheduled to undergo cervical spine surgery under general anesthesia, were recruited. Preoperative assessments included inter-incisor gap (IIG), thyromental distance (TMD), neck circumference (NC), NC/IIG ratio (RNIIG), NC/TMD ratio (RNTMD) and modified Mallampati test (MMT). Cormack-Lehane scales were assessed during intubation. The anesthesiologist was blinded to the airway assessments. RNIIG's ability to predict difficult laryngoscopy was compared with that of established predictors.

Results: Difficult laryngoscopy incidence was 16.4%. Univariate analysis showed that male gender, increased age, weight, NC, RNIIG and RNTMD, decreased IIG and TMD, and MMT 3 and 4 were associated with difficult laryngoscopy. Binary multivariate logistic regression analyses identified only one factor that was independently associated with difficult laryngoscopy: RNIIG. The odds ratio and 95% confidence interval (95% CI) were 1.932 (1.504-2.482). RNIIG (≥9.5) exhibited the largest area under the curve (0.80; 95% CI 0.73-0.86) and the highest sensitivity (88.6%; 95% CI 78.1-99.1) and negative predictive value (96.6%; 95% CI 94.0-99.2), confirming its better predictive ability.

Conclusions: RNIIG is a new and simple predictor with a higher level of efficacy, and could help anesthetists plan for difficult laryngoscopy management in cervical spondylosis patients.

Trial registration: ChiCTR-OON-16008320 (April 19th, 2016).

Keywords: Cervical spondylosis; Difficult laryngoscopy; Intubation.

PubMed Disclaimer

References

    1. De Jong A, Molinari N, Terzi N, Mongardon N, Arnal JM, Guitton C, Allaouchiche B, Paugam-Burtz C, Constantin JM, Lefrant JY, et al. Early identification of patients at risk for difficult intubation in the intensive care unit: development and validation of the MACOCHA score in a multicenter cohort study. Am J Respir Crit Care Med. 2013;187(8):832–9. doi: 10.1164/rccm.201210-1851OC. - DOI - PubMed
    1. Fox WT, Harris S, Kennedy NJ. Prevalence of difficult intubation in a bariatric population, using the beach chair position. Anaesthesia. 2008;63(12):1339–42. doi: 10.1111/j.1365-2044.2008.05639.x. - DOI - PubMed
    1. Adamus M, Fritscherova S, Hrabalek L, Gabrhelik T, Zapletalova J, Janout V. Mallampati test as a predictor of laryngoscopic view. Biomed Pap Med Fac Univ Palacky Olomouc Czech Repub. 2010;154(4):339–43. doi: 10.5507/bp.2010.051. - DOI - PubMed
    1. Shiga T, Wajima Z, Inoue T, Sakamoto A. Predicting difficult intubation in apparently normal patients: a meta-analysis of bedside screening test performance. Anesthesiology. 2005;103(2):429–37. doi: 10.1097/00000542-200508000-00027. - DOI - PubMed
    1. Gonzalez H, Minville V, Delanoue K, Mazerolles M, Concina D, Fourcade O. The importance of increased neck circumference to intubation difficulties in obese patients. Anesth Analg. 2008;106(4):1132–6. doi: 10.1213/ane.0b013e3181679659. - DOI - PubMed

Publication types

LinkOut - more resources