Clinical versus Ultrasound Measurements of Hyomental Distance Ratio for the Prediction of Difficult Airway in Patients with and without Morbid Obesity.

Cristina Petrișor,Adrian Prie,Robert Simon,Constantin Bodolea,Robert Szabo,Sebastian Trancă

doi:10.3390/diagnostics10030140

Cristina Petrișor, Adrian Prie + Show 4 more

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https://doi.org/10.3390/diagnostics10030140

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Abstract

Purpose: To describe the correlation between clinically measured hyomental distance ratio (HMDRclin) and the ultrasound measurement (HMDRecho) in patients with and without morbid obesity and to compare their diagnostic accuracy for difficult airway prediction. Methods: HMDRclin and HMDRecho were recorded the day before surgery in 160 consecutive consenting patients. Laryngoscopy was performed by a skilled anesthesiologist, with grades III and IV Cormack–Lehane being considered difficult views of the glottis. Linear regression was used to assess the correlation between HMDRclin and HDMRecho and receiver operating curve analysis was used to compare the performance of the two for predicting difficult airway. Results: The linear correlation between HMDRclin and HDMRecho in patients without morbid obesity had a Pearson coefficient of 0.494, while for patients with morbid obesity this was 0.14. A slightly higher area under the curve for HMDRecho was oberved: 0.64 (5%CI 0.56–0.71) versus 0.52 (95%CI, 0.44–0.60) (p = 0.34). Conclusion: The association between HMDRclin and HDMRecho is moderate in patients without morbid obesity, but negligible in morbidly obese patients. These might be explained by difficulties in palpating anatomical structures of the airway.

Highlights

Preoperative difficult airway prediction is one of the most important elements for the preanesthetic evaluation and comprises several clinical signs
More than fifteen ultrasonographic measured parameters have been used in prospective studies, among which are the measurements of the hyomental distance (HMD) and hyomental distances ratio (HMDR) [2]
Ultrasound measurements were applied for the hyomental distance ratio (HMDRecho ), with variable sensitivity and specificity [9,10,11,12,13]

Summary

Introduction

Preoperative difficult airway prediction is one of the most important elements for the preanesthetic evaluation and comprises several clinical signs. As none of the clinical signs has absolute diagnostic value and none can exclude difficult intubation, there is a continuous search for a predictive test with improved diagnostic accuracy that identifies patients at risk for airway problems, such as the inability to intubate and/or ventilate. HMDR measured clinically (HMDRclin ) was investigated for difficult airway prediction in anesthesia more than 10 years ago. The diagnostic accuracy of this parameter varied widely in subsequent studies, suggesting that evaluation of clinical parameters might be operator-dependent or that there might be difficulties regarding the palpation of the hyoid bone in certain patients [4,5,6,7,8]. Until now, each of the previous studies on HMDR focused on a single technique of measurement, either clinical or ultrasonographical, and no study compared the two

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