Does neck circumference help to predict difficult intubation in obstetric patients? A prospective observational study

Riad, Waleed; Ansari, Tarek; Shetty, Nanda

doi:10.4103/sja.sja_385_17

Cited by 22 publications

(15 citation statements)

References 21 publications

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“…There were 218 test comparisons from 92 studies for difficult laryngoscopy, 72 comparisons from 50 studies for difficult intubation, 18 comparisons from seven studies for difficult facemask ventilation and two comparisons from two studies for failed intubation. Overall, the median (IQR [range]) number of participants per study, proportion of female participants, age and body mass index were 380 (200–662 [14–103,728]), 53% (44–64% [0–100%]), 45 (39–52 ) years and 27.3 (24.8–30.0 ) kg.m −2 , respectively. All studies except four performed airway management in operating theatres, two in the pre‐hospital setting and the others occurred in emergency rooms.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Bedside tests for predicting difficult airways: an abridged Cochrane diagnostic test accuracy systematic review

et al. 2019

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Although bedside screening tests are routinely used to identify people at high risk of having a difficult airway, their clinical utility is unclear. We estimated the diagnostic accuracy of commonly used bedside examination tests for assessing the airway in adult patients without apparent anatomical abnormalities scheduled to undergo general anaesthesia. We searched for studies that reported our pre-specified bedside index screening tests against a reference standard, published in any language, from date of inception to 16 December 2016, in seven bibliographic databases. We included 133 studies (127 cohort type and 6 case-control) involving 844,206 participants. Overall, their methodological quality (according to QUADAS-2, a standard tool for assessing quality of diagnostic accuracy studies) was moderate to high. Our pre-specified tests were: the Mallampati test (6 studies); modified Mallampati test (105 studies); Wilson risk score (6 studies); thyromental distance (52 studies); sternomental distance (18 studies); mouth opening test (34 studies); and the upper lip bite test (30 studies). Difficult facemask ventilation, difficult laryngoscopy, difficult intubation and failed intubation were the reference standards in seven, 92, 50 and two studies, respectively. Across all reference standards, we found all index tests had relatively low sensitivities, with high variability, but specificities were consistently and markedly higher than sensitivities. For difficult laryngoscopy, the sensitivity and specificity (95%CI) of the upper lip bite test were 0.67 (0.45-0.83) and 0.92 (0.86-0.95), respectively; upper lip bite test sensitivity (95%CI) was significantly higher than that for the mouth opening test (0.22, 0.13-0.33; p < 0.001). For difficult tracheal intubation, the modified Mallampati test had a significantly higher sensitivity (95%CI) at 0.51 (0.40-0.61) compared with mouth opening (0.27, 0.16-0.41; p < 0.001) and thyromental distance (0.24, 0.12-0.43; p < 0.001). Although the upper lip bite test showed the most favourable diagnostic test accuracy properties, none of the common bedside screening tests is well suited for detecting unanticipated difficult airways, as many of them are missed.

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Section: Resultsmentioning

confidence: 99%

“…We identified further studies from references of retrieved articles and used citation tracking in Science Citation Index. The search was updated in March 2018 but we have not incorporated the results from 27 studies in this review.…”

Section: Methodsmentioning

confidence: 99%

Bedside tests for predicting difficult airways: an abridged Cochrane diagnostic test accuracy systematic review

et al. 2019

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“…These findings support that the NC and TMHT may be predictors of DL. Several studies showed promising results, even with a single predictor [4,[16][17][18][19][20][21][22]. However, the previous studies are different from those of ours.…”

Section: Discussionmentioning

confidence: 74%

“…The vast majority of the studies on prediction of difficult airway using NC is on obese patients so data in non-obese are insufficient [8,16,17]. There were also differences in the primary outcome (difficult intubation vs. DL) [8,18,[20][21][22]. There may be differences in some TMHT studies because the patient population is of different races from the patient population in our study.…”

Section: Discussionmentioning

confidence: 83%

Development and validation of a difficult laryngoscopy prediction model using machine learning of neck circumference and thyromental height

Kim

Jang

et al. 2021

BMC Anesthesiol

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Background Predicting difficult airway is challengeable in patients with limited airway evaluation. The aim of this study is to develop and validate a model that predicts difficult laryngoscopy by machine learning of neck circumference and thyromental height as predictors that can be used even for patients with limited airway evaluation. Methods Variables for prediction of difficulty laryngoscopy included age, sex, height, weight, body mass index, neck circumference, and thyromental distance. Difficult laryngoscopy was defined as Grade 3 and 4 by the Cormack-Lehane classification. The preanesthesia and anesthesia data of 1677 patients who had undergone general anesthesia at a single center were collected. The data set was randomly stratified into a training set (80%) and a test set (20%), with equal distribution of difficulty laryngoscopy. The training data sets were trained with five algorithms (logistic regression, multilayer perceptron, random forest, extreme gradient boosting, and light gradient boosting machine). The prediction models were validated through a test set. Results The model’s performance using random forest was best (area under receiver operating characteristic curve = 0.79 [95% confidence interval: 0.72–0.86], area under precision-recall curve = 0.32 [95% confidence interval: 0.27–0.37]). Conclusions Machine learning can predict difficult laryngoscopy through a combination of several predictors including neck circumference and thyromental height. The performance of the model can be improved with more data, a new variable and combination of models.

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“…In a general population, prediction of difficult intubation and mask ventilation is very insensitive and poorly specific [152], and combined tests add little to single tests [141]. In the general obstetric population, the factors associated with difficult intubation appear to be the same as for non-pregnant patients, including high Mallampati score, short neck, receding mandible, protruding maxillary incisors [153] and increased neck circumference [154]. Potential difficulties with mask ventilation were explicitly considered in some case reports, usually leading to a decision for awake intubation.…”

Section: Airway Assessment / Definitionmentioning

confidence: 99%

Anticipated difficult airway during obstetric general anaesthesia: narrative literature review and management recommendations.

2020

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We reviewed the literature on management of general and regional anaesthesia in pregnant women with anticipated airway difficulty. We identified 138 publications comprising 158 cases; these either described equipment or techniques for the provision of general anaesthesia, or the management of women with regional analgesia or anaesthesia, with the aim of avoiding general anaesthesia. Most of the former group described women requiring caesarean section alone, or in combination with other surgery, which was sometimes airwayrelated. Management techniques were largely similar to those in non-obstetric patients requiring surgery who have airway difficulties, although suggested differences related to physiological changes of pregnancy and avoidance of nasal intubation. In the reports discussing regional anaesthesia, consideration was often given to the possible requirement for urgent out-of-hours anaesthetic intervention, and the predicted difficulty of management of general anaesthesia should it be required. In a number of reported cases, multidisciplinary planning led to the conclusion that elective caesarean section should be performed in order to avoid emergency airway management. Based on this literature review, we advise antenatal planning that includes: assessment of the patient's clinical characteristics; consideration of the equipment and personnel available to provide safe airway management out-of-hours; and elective caesarean section should these be lacking. If general anaesthesia is required, a risk assessment must be made as to the probability of safe airway management after the induction of anaesthesia, and awake tracheal intubation should be used if this cannot be assured. Decision aids are provided to illustrate these points. Online appendices include a comprehensive compendium of case reports on the management of a number of rare syndromes and airway conditions.

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Does neck circumference help to predict difficult intubation in obstetric patients? A prospective observational study

Cited by 22 publications

References 21 publications

Bedside tests for predicting difficult airways: an abridged Cochrane diagnostic test accuracy systematic review

Bedside tests for predicting difficult airways: an abridged Cochrane diagnostic test accuracy systematic review

Development and validation of a difficult laryngoscopy prediction model using machine learning of neck circumference and thyromental height

Anticipated difficult airway during obstetric general anaesthesia: narrative literature review and management recommendations.

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