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Updated: Jul 24, 2025
A Novel Rescue Technique for Difficult Intubation and Difficult Ventilation
Published on: January 17, 2011
Prevalence and risk factors of difficult mask ventilation: A systematic review and meta-analysis
Kuo-Chuan Hung1, Min-Hsiang Chuang2, Fu-Chi Kang3
1School of Medicine, College of Medicine, National Sun Yat-sen University, Kaohsiung City, Taiwan; Department of Anesthesiology, Chi Mei Medical Center, Tainan City, Taiwan.
Study Objective:
This meta-analysis aimed at identifying the risk factors for and their strengths in predicting difficult mask ventilation (MV) through a systematic approach.
Design:
Meta-analysis of observational studies.
Setting:
Operating room.
Intervention:
Airway- or patient-related risk factors for difficult MV reported in over 20% of eligible studies identified through literature review.
Patients:
Adults receiving anesthetic induction with requirement of MV.
Measurements:
Databases including EMBASE, MEDLINE, Google Scholar, and Cochrane Library were searched from inception to July 2022. The primary outcomes were the identification of commonly reported risk factors for MV and a comparison of their strengths in difficult MV prediction, while the secondary outcomes were the prevalence of difficult MV in the general population and those with obesity.
Main Results:
Meta-analysis of 20 observational studies involving 335,846 patients identified 13 risk factors with predictive strengths (all p < 0.05): neck radiation (OR = 5.0, five studies, n = 277,843), increased neck circumference (OR = 4.04, 11 studies, n = 247,871), obstructive sleep apnea (OSA) (OR = 3.61, 12 studies, n = 331,255), presence of beard (OR = 3.35, 12 studies, n = 295,443), snoring (OR = 3.06, 14 studies, n = 296,105), obesity (OR = 2.99, 11 studies, n = 278,297), male gender (OR = 2.76, 16 studies, n = 320,512), Mallampati score III-IV (OR = 2.36, 17 studies, n = 335,016), limited mouth opening (OR = 2.18, six studies, n = 291,795), edentulous (OR = 2.12, 11 studies, n = 249,821), short thyroid-mental distance (OR = 2.12, six studies, n = 328,311), old age (OR = 2, 11 studies, n = 278,750), and limited neck movement (OR = 1.98, nine studies, n = 155,101). The prevalence of difficult MV was 6.1% (16 studies, n = 334,694) and 14.4% (four studies, n = 1152) in the general population and those with obesity, respectively.
Conclusions:
Our results demonstrated the strengths of 13 most common risk factors for predicting difficult MV, which may serve as an evidence-based reference for clinicians to incorporate into their daily practice.
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