Highlights
- •Pregnancy alters airway anatomy and physiology, making airway management difficult.
- •We compared ultrasound airway parameters between pregnant and non-pregnant.
- •Most ultrasound-assessed airway parameters were significantly different between them.
- •The pre-E and pre-E/E-VC ratio moderately predict a difficult airway in pregnancy.
- •Pregnancy, hyoid bone visibility and pre-E/E-VC ratio were independent predictors.
Abstract
Background
Clinical airway assessment parameters differ significantly between pregnant and non-pregnant
patients, however literature comparing their ultrasound (US) airway parameters is
limited. We planned a prospective cohort study to compare US-assessed airway parameters
between pregnant and non-pregnant women.
Methods
We enrolled 82 pregnant females scheduled for elective cesarean section under neuraxial
anesthesia and 80 age-matched non-pregnant females scheduled for elective surgery.
Pre-operative clinical airway assessment was performed in both groups. The US airway
assessment was done pre-operatively in non-pregnant and postoperatively in pregnant
patients. Our primary objective was to compare US-assessed parameters, and secondary
objectives included a comparison of clinical airway assessment parameters and investigating
a relationship between a difficult airway (defined as a modified Mallampati grade
(MMG) ≥ 3) and other airway assessment parameters.
Results
Among several US airway parameters, pregnant patients had significantly higher hyomental
distance, anterior neck soft tissue thickness at the hyoid and vocal cord level, and
oral cavity height, while the tongue thickness and mandibular condylar movements were
significantly lower than in non-pregnant patients. Similarly, for the clinical airway
assessment, pregnant patients had significantly higher MMG and upper lip bite test
scores, mentohyoid distance, and neck circumference. Pregnancy, the ratio of pre-epiglottic
space and epiglottis-to-vocal cords distance (Pre-E/E-VC), and hyoid bone visibility
were independent predictors of a difficult airway.
Conclusion
The US airway assessment parameters differ significantly between pregnant and non-pregnant
patients. Pregnancy, hyoid bone visibility, and Pre-E/E-VC ratio were independent
predictors of the difficult airway in female patients.
Keywords
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Article info
Publication history
Published online: December 28, 2022
Accepted:
December 22,
2022
Identification
Copyright
© 2022 Elsevier Ltd. All rights reserved.
