Diagnostic Accuracy Of Distance From Skin To Epiglottis In Predicting Difficult Airway Using Ultrasonographic Airway Assessment

Diagnostic Accuracy Of Distance From Skin To Epiglottis In Predicting Difficult Airway Using Ultrasonographic Airway Assessment

Introduction

One of the prime responsibilities of the anesthesiologist is to provide adequate ventilation by securing the patient’s airway. Preoperative assesment of the patient’s airway facilitates to predict the difficult airway The diagnostic precision of a pre-anesthetic airway checkup in predicting difficult intubation is very low, and unpredicted difficult intubations persist. The diagnostic accuracy of these pre-anesthetic airway screening parameters has varied results in various studies. Recently, ultrasound (USG) guided airway assessment is showing encouraging results. However, few research studies have studied the role of ultrasonographic measurements in detecting difficult airways preoperatively.

The objective behind our study is to search for a simple and bedside noninvasive method to identify difficult airway As there are only less number studies predicting difficult airway using this predictor i would like to do my study with predictor for assesing diffficult airway

OBJECTIVES

Primary objective

To compute the diagnostic accuracy of distance from skin to epiglottis through Ultrasound assessment in predicting difficult airway

secondary objective

To assess the sensitivity, specificity, positive predictive value and negative predictive value

Study design Prospective observational study

Number of subjects/sample size The minimum sample size for the study has been calculated to 100

Study Methodology or procedure

Inclusion criteria : Age: 18-65 years ASA grade -1,2,3,4 Patients undergoing surgery under general anaesthesia.

Exclusion criteria : Patients who denies consent Patients with prominent features of the difficult airway with facial abnormalities Morbid obesity (body mass index, BMI more than 35 kg/m2) Restricted mouth opening Cervical spine anomalies Uncooperative and pregnant patients

After obtaining approval from Ethics committee Informed and written consent will be obtained from all patients • PREOPERATIVE ASSESSMENT: Detailed history and physicalexamination, baseline data like HR,BP and basic investigations will be collected. MMP grading (1,2,3,4),Mouth opening (more or less than 3 finger breath) ,Thyromental distance(more or less than 6.5 cm) ,Hyomental distance (more or less than 3 finger breath) ,BMI (More or less than 35 Sq.cm) ,Neck circumference (more or less than 34 cm) ,Neck movements (ROM adequate or not adequate ) will be noted An IV access with 18G IV cannula will be secured for all patients. Premedication such as Tab Ranitidine 150mg and Tab Alprazolam 0.5mg given a night before surgery and 6 am on the day of surgery All patients will undergo detailed preoperative ultrasonographic evaluation. Ultrasonographic airway evaluation will be done with a linear highfrequency probe. The Ultrasonographic measurement of the airway will be achieved with the patient in supine and the head and neck in the neutral position without a pillow, looking straight ahead with the mouth closed. Skin to epiglottis distance is noted. Study outcome or end points To preoperatively diagnose the difficult airway using ultrasound (skin to epiglottis distance)in patients undergoing surgery under general anaesthesia.

Ethical Considerations Approval from Chettinad Hospital and Research Institute IHEC (institutional human ethical committee) has been  obtained before starting the study. All participants will be informed regarding the purpose of study, benefits, procedure and confidentiality of the research study in their local language and in English. An informed and written consent will be taken from person who willing to participate in study

Study Duration (in Months / Years)  6 months

References

1. Agung Senapathi TG, Wiryana M, Aryabiantara IW, Ryalino C, Roostati RL. The predictive value of skin-to-epiglottis distance to assess difficult intubation in patients who undergo surgery under general anesthesia. Bali J Anaesthesiol 2020 4 46 8

2. Harjai M, Alam S, Rastogi S, et al. (July 15, 2023) Effectiveness and Validity of Preoperative Ultrasonographic Airway Assessment and Clinical Screening Tests to Predict Difficult Laryngoscopy: A Prospective, Observational Study. Cureus 157 e41933. DOI 10.7759 cureus.4193 3 tests in the evaluation of difficult airways preoperatively

3. Soltani Mohammadi S, Tavakkoli A, Marashi M. Correlation between Ultrasound Measured Distance from Skin to Epiglottis and Epiglottis to Mid-Vocal Cord with Cormack-Lehane Classification for Predicting Difficult Intubation. Arch Anesth & Crit Care. 2019 6123 26

4. Udayakumar G, Priya L, Narayanan V (July 05, 2023) Comparison of Ultrasound Parameters and Clinical Parameters in Airway Assessment for Prediction of Difficult Laryngoscopy and Intubation: An Observational Study. Cureus 15 7 e41392. DOI 10.7759 cureus.41392