Available online 2 September 2023, 101291

Presentation: This meta-analysis was presented at the Euroanesthesia 2022, 4–6 June 2022, Milan, Italy.

DSEM is one of the most studied parameters in prediction of difficult airway.

Diagnostic test accuracy of US-DSEM in difficult airway prediction was evaluated.

Strict inclusion criteria were used to standardise the US-DSEM.

Despite its accuracy, US-DSEM should not replace clinical screening tests.

US-DSEM should be used along with clinical screening tests rather than alone.

The studies investigating distance from the skin to epiglottis measurements by ultrasonography (US-DSEM) for prediction of difficult laryngoscopy are inconclusive and non-standardised.

We aimed to assess the diagnostic test accuracy (DTA) of US-DSEM relative to Cormack Lehane 3–4 for diagnosing difficult laryngoscopy using a meta-analysis method.

Strict inclusion criteria were used to provide clear definition of how to measure US-DSEM. PubMed, Cochrane Library, Embase and Google Scholar were searched for papers published between January 2005 and March 2021 to perform a systematic review and DTA meta-analysis. Publications reporting data on US-DSEM in difficult laryngoscopy prediction in adults with normal airway were included. Exclusions were obese or pregnant patients and patients with difficult airway predictors and those in which the measurements were made in a position other than supine and neutral positions. The pooled sensitivity, specificity, positive/negative likelihood ratios (PLR/NLR), diagnostic odds ratio (DOR), and area under the hierarchic summary receiver operating characteristics curve (AU-HSROC) were determined.

1244 patients from nine studies were included. Pooled sensitivity: 0.68 (95%CI 0.39–0.87), specificity: 0.76 (95%CI 0.68–0.83), PLR: 2.87 (95%CI 2.20–3.73), NLR: 0.42 (%95CI 0.20–0.87), DOR: 6.80 (95%CI 2.72–17.3), and AU-HSROC: 0.79 (0.75–0.82) were the results. No threshold effect (r = 0.53, p = 0.137) and publication bias (p = 0.540) existed.

This meta-analysis showed that US-DSEM measured with linear probe placed transversely at the thyrohyoid membrane level with midline approach and neutral head position is accurate and has diagnostic value in predicting difficult laryngoscopy. However, its sensitivity and specificity are not sufficient to replace clinical tests.

Diagnostic test

Airway management

Ultrasound

Meta-analysis

Systematic review

Diagnostic imaging

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