Laryngoscopy

The goal of this observational study is to evaluate thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL); to know which correlates better with the incisor vallecula distance (IVD). Based on the direction and strength of the correlation measure, a multiple regression equation can then be created to first predict the IVD with external linear measure, and second, based on IVD length prediction, the appropriate laryngoscope blade size can be ascertained.

This prospective, multicenter observational study aims to evaluate the effect of different flow rates of high-flow nasal oxygen (HFNO) on the quality of the laryngoscopic view during videolaryngoscopy in adult patients undergoing general anesthesia. Each patient will serve as their own control, with repeated measurements obtained at three different HFNO flow settings (0, 40, and 60 L/min). The study will assess objective and subjective parameters of glottic visualization using standardized scoring systems.

Impact of using video laryngoscopy versus direct laryngoscopy technique in terms of improved hemodynamics post intubation and time taken for intubation.

Participants will undergo routine pre-operative evaluation. An intravenous line will be placed in the recovery area. On arrival in the operating room, standard monitoring (blood pressure, heart rate, oxygen saturation, ECG, breathing monitor, and temperature) will be applied. A central venous catheter and an arterial line will be inserted under local anesthesia using sterile technique. Before anesthesia induction, patients will receive premedication including midazolam and an opioid pain-relief injection given slowly through the vein. General anesthesia will then be induced with etomidate. After adequate sedation, a muscle relaxant (atracurium) will be administered, and the patient will be ventilated with 100% oxygen using a face mask. The breathing tube will then be inserted and correct placement confirmed. During surgery, anesthesia will be maintained with oxygen, sevoflurane gas, and a continuous atracurium infusion. Hemodynamic parameters such as heart rate and blood pressure will be monitored throughout the peri-intubation and intraoperative period.

Patient safety is the cornerstone of anesthetic practice, and maintaining adequate respiration represents its most critical initial step. In situations where spontaneous breathing cannot be sustained-such as during general anesthesia-the airway must be mechanically secured. While simple face masks may be sufficient in some cases, endotracheal intubation remains the most reliable method for airway control in conditions associated with respiratory depression. Airway management may be challenging due to various patient-related anatomical factors, including facial and mandibular structure, obesity, limited mouth opening, facial hair, sunken cheeks, wide facial morphology, and a short or muscular neck. These challenges are collectively described as difficult ventilation and difficult intubation (cannot ventilate-cannot intubate), which may occur unexpectedly or be anticipated. A difficult airway is defined as difficulty encountered by a trained anesthesiologist in face mask ventilation, tracheal intubation, or both. Several predictors of difficult airway are widely accepted, such as thyromental and sternomental distances, neck circumference, Mallampati classification, upper lip bite test, mouth opening, and interincisor distance. Thorough preoperative airway evaluation is mandatory, as difficult mask ventilation and failed intubation remain major contributors to anesthesia-related morbidity and mortality. Although numerous studies have examined these predictors, research focusing on facial morphology and anthropometric indices-particularly the face index-is extremely limited. Facial morphology varies considerably among individuals and can be evaluated anthropometrically using simple, noninvasive tools such as a digital caliper. Anthropometric analysis is commonly applied in forensic medicine and reconstructive surgery but has rarely been incorporated into airway assessment. This study aims to introduce face index analysis as a novel predictor of difficult airway alongside conventional methods. By evaluating measurements such as trichion-gnathion distance, total facial index, upper facial index, and nasal index, the study investigates whether airway difficulty can be predicted using a single index value. All measurements are standard, noninvasive, and routinely performed during preoperative assessment.

This study aims to evaluate the effect of increasing preoperative timing of single dexmedetomidine on the stress response of laryngoscopy and intubation.

The aim of this study is to compare the efficacy of oral melatonin versus nebulized dexmedetomidine in attenuating the hemodynamic response to direct laryngoscopy and endotracheal intubation in controlled hypertensive patients prepared for general anesthesia

This study aims to develop a comprehensive airway assessment score including traditional bedside clinical tests and ultrasound measurements with high accuracy in predicting difficult airway, and to validate it through testing it on a large population sample. The main question it aims to answer is: Is the comprehensive scoring system that includes clinical bedside and ultrasound measurements developed to predict difficult airways valid in a large population sample? Adult patients undergoing general anesthesia with American Society of Anesthesiologists (ASA) classification 1-4 will be recruited. Traditional and ultrasound measurements will be collected.

This study evaluates the correlation between sedation depth monitoring obtained by NeuroSENSE ® NS 701 Monitor and reflexes during intravenous anesthesia in children undergoing direct laryngoscopy for surgical procedures.

Clinical screening tests were included to define a difficult laryngoscopy such as history of difficult or impossible intubation, NC, MMS, retrognathia, protrusion of the upper incisors, TMD, mouth opening, dentition, macroglossia, presence of a beard, UBLT, spine mobility and palm print test for diabetes. Ultrasound airway assessment was performed: Clinical screening tests were included to define a difficult laryngoscopy such as history of difficult or impossible intubation, NC, MMS, retrognathia, protrusion of the upper incisors, TMD, mouth opening, dentition, macroglossia, presence of a beard, UBLT, spine mobility and palm print test for diabetes. Ultrasound airway assessment was performed Three parameters were measured to calculate the scores: Tongue thickness (TT) in coronal plane, Distance from the skin to hyoid bone (SHB), Distance from the skin to the thyrohyoid membrane (STM). Two scores were developed from a study conducted in 2019. The first score, to predict a difficult laryngoscopy, uses two parameters: the modified MALLAMPATI class (MMS) and the STM. A score strictly greater than 2 is predictive of a difficult laryngoscopy. The second score, to predict difficult ventilation, uses four parameters: BMI, NC, TT in coronal plane, and SHB. A score strictly greater than 20 is predictive of difficult ventilation. A well-experienced anesthesiologist performed a direct laryngoscopy and graded it as Cormack-Lehane's grading. Difficulty in intubation and/or mask ventilation was managed according to the 2017 SFAR guidelines.