Observational studyIrish journal of medical science2015
Predicting difficult airways: 3-3-2 rule or 3-3 rule?
Observational study in Irish journal of medical science, 2015. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers, 1 of them a synthesis that pooled it.
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The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
7 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Airway physical examination tests for detection of difficult airway management in apparently normal adult patients.The Cochrane database of systematic reviews · 2018Pooled it
- Expert consensus on difficult airway assessment.Hepatobiliary surgery and nutrition · 2023Review
- Development and validation of a regression model with nomogram for difficult video laryngoscopy in Chinese population: a prospective, single-center, and nested case-control study.Frontiers in medicine · 2023Article
- A Prospective Study to Correlate Difficult Intubation with Difficult Laryngeal Exposure for Microlaryngeal Surgery using Various Grading Scales of Difficult Intubation.Indian journal of otolaryngology and head and neck surgery : official publication of the Association of Otolaryngologists of India · 2022Article
- Nomograms for predicting difficult airway based on ultrasound assessment.BMC anesthesiology · 2022Observational
- A clinical prediction rule to identify difficult intubation in children with Robin sequence requiring mandibular distraction osteogenesis based on craniofacial CT measures.BMC anesthesiology · 2019Article
- The Relationship between Orotracheal Intubation Difficulty Scoring Systems and Anthropometric Factors.Advanced journal of emergency medicine · 2019Article
Corrections and comments
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Authors and funding
8 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe goal of this study was to assess the value of the 3-3 rule and the 3-3-1 rule in predicting difficult airways.
methodsThe authors conducted an observational study over a 6-month period. For each consenting adult patient undergoing general anesthesia, preoperative patient characteristics and data regarding difficult airway assessments and airway outcomes were collected. The 3-3-2 rule, 3-3-1 rule and 3-3 rule were included in preoperative difficult airway assessments. The 3-3-1 rule is defined as an interincisor distance (IID) less than three fingers, a hyoid-mental distance (HMD) less than three fingers, and a hyoid-thyroid cartilage distance (HTD) less than one finger.
resultsAmong the 732 patients who were successfully recruited in this study, 67 patients had difficult laryngoscopy (DL) (9.2 %), and 25 patients had difficult intubation (DI) (3.4 % of the total). All of the DI patients were also DL patients (25/67, 37.3 %). The AUC of the 3-3-2, 3-3, and 3-3-1 rules for predicting difficult laryngoscopy were 0.702, 0.709, and 0.631, respectively. Significant differences between the 3-3-2 and 3-3-1 rules as well as between the 3-3 and 3-3-1 rules were evident. The AUC values for the 3-3-2, 3-3, and 3-3-1 rules for predicting DI were 0.830, 0.822, and 0.725, respectively.
conclusionsThe 3-3 rule and the 3-3-2 rule are similar regarding their ability to predict difficult airways. A HTD less than two fingers or one finger is not predictive of DV or DI.
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