Useful Ultrasonographic Parameters to Predict Difficult Laryngoscopy and Difficult Tracheal Intubation-A Systematic...

Area of Science:

• Anesthesiology and critical care medicine
• Medical imaging
• Otolaryngology

Background:

• Unexpected difficult airway management poses significant risks, including morbidity and mortality, during elective procedures.
• Ultrasonography shows promise for perioperative airway assessment, but specific sonographic predictors for difficult laryngoscopy and tracheal intubation remain unclear.
• Routine application of ultrasonography for airway assessment requires identification of reliable predictive parameters.

Approach:

• A systematic review and meta-analysis was conducted to identify ultrasonographic predictors of difficult airways.
• Literature search included PubMed, Web of Science, and Embase, focusing on human primary studies predicting difficult laryngoscopy or tracheal intubation using ultrasonography.
• Data from 19 articles (4,570 patients) for the systematic review and 12 articles (1,141 patients) for the meta-analysis were analyzed using PRISMA methodology.

Key Points:

• Twenty-six sonographic parameters were evaluated for their predictive value.
• Significant parameters included skin-to-hyoid bone distance, skin-to-epiglottis distance, skin-to-anterior commissure of vocal cords distance, pre-epiglottis space to epiglottis-vocal cord midpoint distance, hyomental distance in neutral and extended positions, and the ratio of hyomental distance in neutral to extended positions.
• Hyomental distance in the neutral position emerged as the most reliable parameter.

Conclusions:

• Hyomental distance in the neutral position is the most dependable ultrasonographic parameter for pre-operative airway assessment.
• Limitations include small sample sizes, study heterogeneity, and the lack of a standardized ultrasonographic evaluation method.
• Further research with standardized methods and larger sample sizes is warranted to confirm these findings.