Difficult Laryngoscopy—the “Anterior” Larynx and the Atlanto-Occipital Gap

Nichol, Hamish; Zuck, D.

doi:10.1093/bja/55.2.141

Cited by 119 publications

(26 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The difference in findings of these studies may be explained by the fact that the investigators in the study were two otolaryngologists who used different instrumentations and techniques for direct laryngoscopy than that routinely used by anaesthesiologists to accomplish endotracheal intubation. Our finding of no significant difference in the atlanto-occipital gap, which was found to be a significant parameter by White and Kander[34] is in agreement with Nichol and Zuck[36] who reported a wide variation in the atlanto-occipital distance. It would be inappropriate to speak in terms of ‘normal’ and ‘abnormal’.…”

Section: Discussionsupporting

confidence: 93%

Diagnostic value of the upper lip bite test in predicting difficulty in intubation with head and neck landmarks obtained from lateral neck X-ray

Khan

Arbabi

2013

Indian J Anaesth

View full text Add to dashboard Cite

Background:Unanticipated difficult tracheal intubation remains a primary concern of anaesthesiologists and upper lip bite test (ULBT) is one of the assessments used in predicting difficult intubation. In this study, we aimed to check the utility of lateral neck X-ray measurements in improving the diagnostic value of the ULBT.Methods:In a prospective study conducted from January 2007 until December 2010, we recorded personal and demographic data of 4500 patients who entered the study and subjected them to standard lateral neck radiography. Before the induction of anaesthesia, clinical examination and ULBT results were recorded and during induction of anaesthesia laryngoscopic grading was evaluated and recorded in questionnaires. All the compiled data were analysed by SPSS 14.0 (SPSS Inc., Chicago, IL, USA) software. Diagnostic value for each test was calculated and compared.Results:Negative predictive values (NPVs) were high in all tests. ULBT had the highest specificity and NPV compared with the other tests. The positive predictive value for all the tests had been low, but marginally high in the ULBT.Conclusion:Although all the tests used had relatively acceptable predictive values, combination of tests appeared to be more predictive. Highest sensitivities were observed with ULBT, mandibulohyoid distance and thyromental distance respectively. Use of radiological parameters may not be suitable as screening tools, but may help in anticipating and preparing for a difficult scenario.

show abstract

Section: Discussionsupporting

confidence: 93%

Diagnostic value of the upper lip bite test in predicting difficulty in intubation with head and neck landmarks obtained from lateral neck X-ray

Khan

Arbabi

2013

Indian J Anaesth

View full text Add to dashboard Cite

show abstract

“…The head extension is an important factor in determining the ease or difficulty of tracheal intubation. [13] Whether SMDD can be used as an indirect measure of atlantooccipital extension needs further investigation.…”

Section: Discussionmentioning

confidence: 99%

Sternomental distance and sternomental displacement as predictors of difficult laryngoscopy and intubation in adult patients

Prakash

Mullick

Bhandari³

et al. 2017

Saudi J Anaesth

View full text Add to dashboard Cite

Background:Several morphometric airway measurements have been used to predict difficult laryngoscopy (DL). This study evaluated sternomental distance (SMD) and sternomental displacement (SMDD, difference between SMD measured in neutral and extended head position), as predictors of DL and difficult intubation (DI).Materials and Methods:We studied 610 adult patients scheduled to receive general anesthesia with tracheal intubation. SMD, SMDD, physical, and airway characteristics were measured. DL (Cormack-Lehane grade 3/4) and DI (assessed by Intubation Difficulty Scale) were evaluated. The optimal cut-off points for SMD and SMDD were identified by using receiver operating characteristic (ROC) analysis. Multivariate logistic regression was used to predict DL and ROC curve was used to assess accuracy on developed regression model.Results:The incidence of DL and DI was 15.4% and 8.3%, respectively. The cut-off values for SMD and SMDD were ≤14.75 cm (sensitivity 66%, specificity 60%) and ≤5.25 cm (sensitivity 70%, specificity 53%), respectively, for predicting DL. The area under the curve (AUC) with 95% confidence interval (CI) for SMD was 0.66 (0.60–0.72) and that for SMDD was 0.687 (0.63–0.74). Multivariate analysis with logistic regression identified inter-incisor distance, neck movement <80°, SMD, SMDD, short neck and history of snoring as predictors and the predictive model so obtained exhibited a higher diagnostic accuracy (AUC: 0.82; 95% CI 0.77–0.86). SMDD, but not SMD, correlated with DI.Conclusions:Both SMD and SMDD provide a rapid, simple, objective test that may help identifying patients at risk of DL. Their predictive value improves considerably when combined with the other predictors identified by logistic regression.

show abstract

“…In certain patients, the causes are obvious such as the facial deformity, abnormal limitation of the temporomandibular joint movement,[5] hypopharyngeal disease, limited neck extension (<35°), a distance between the tip of the patient’s mandible and hyoid bone of less than 7 cm, a sternomental distance of less than 12.5 cm with the fully extended head and mouth closed, and a poorly visualized uvula during voluntary tongue protrusion. [6] Obesity may create anatomical difficulties for the laryngoscopy caused by the decreased mobility and enlargement of structures in the throat and around the neck. [7] Cervical trauma, cervical arthritis, or previous cervical fusion may restrict the desired sniffing position of head.…”

Section: Discussionmentioning

confidence: 99%

Assessment of difficult laryngoscopy by electronically measured maxillo-pharyngeal angle on lateral cervical radiograph: A prospective study

Gupta

2010

Saudi J Anaesth

View full text Add to dashboard Cite

Background:Difficult airway continued to be a major cause of anesthesia-related morbidity and mortality. Successful airway management depends on direct laryngoscopy and tracheal intubation. Difficult laryngoscopy is a resultant of incomplete structural arrangements during the process of head positioning. Through clinical history, examination of the patients along with craniofacial indices alerts the anesthetist for difficult laryngoscopy. But it does not predict all causes of difficult laryngoscopy during pre-anesthetic evaluation. The maxillo-pharyngeal angle, an upper airway anatomical balance, was proposed for better understanding the pathophysiology of difficult laryngoscopy. In our study we have assess difficult laryngoscopy by electronically measuring maxillo-pharyngeal angles on a lateral cervical radiograph. This angle is normally greater than 100°. Less than 90° angle suggests either impossible or difficult direct laryngoscopy when all known craniofacial indices were within the normal range. Cervical radiographic assessment is a simple, economical, and non-invasive predictive method for difficult laryngoscopy. It should be used routinely along with other indices as pre-anesthetic airway assessment criteria to predict the difficult laryngoscopy.Context:Difficulties with airway management continue to be a major cause of anesthesia-related morbidity, mortality, and litigation. Pre-operative assessment of difficult laryngoscopy by the simple and non-invasive radiological method can help to prevent them.Aims:To assess the difficult laryngoscopy pre operatively by a simple and non invasive radiological method by electronically measuring maxillo-pharyngeal angle on a lateral cervical radiograph and it’s correlation with Cormack and Lehane grading.Settings and Design:This is a controlled, nonrandomized, prospective, cohort observation study.Patients and Methods:The 157 adult consented patients of ASA grade I to III of either sex, scheduled for elective surgery under general anesthesia with endo-tracheal intubation, were studied. The patients with identified difficult airway indices were excluded from the study. The maxillo-pharyngeal angle was electronically measured on a lateral cervical radiograph and was correlated with ease or difficulty of laryngoscopy under general anesthesia. Their degree of laryngeal exposure according to Cormack and Lehane classification grade was also noted.Statistical Analysis used:We performed univariate analyses to evaluate the association between the covariates and direct laryngoscopy.Results:In 148 patients (94.28%), the maxillo-pharyngeal angle was more than 100°, in 7 patients (4.45%) it was less than 90°, and in 2 patients (1.27%) the M-P angle was less than 85° with normal craniofacial indices. When the MP angle was less than 90°, the direct laryngoscopy was difficult which could be compared with to Cormack and Lehane classification grade III and IV.Conclusions:Lateral cervical radiographic assessment should be used as pre-anesthetic airway assessment criteria to predict the d...

show abstract

Difficult Laryngoscopy—the “Anterior” Larynx and the Atlanto-Occipital Gap

Cited by 119 publications

References 0 publications

Diagnostic value of the upper lip bite test in predicting difficulty in intubation with head and neck landmarks obtained from lateral neck X-ray

Diagnostic value of the upper lip bite test in predicting difficulty in intubation with head and neck landmarks obtained from lateral neck X-ray

Sternomental distance and sternomental displacement as predictors of difficult laryngoscopy and intubation in adult patients

Assessment of difficult laryngoscopy by electronically measured maxillo-pharyngeal angle on lateral cervical radiograph: A prospective study

Contact Info

Product

Resources

About