Clinical Research Directory

LeHeR Maneuver vs Sniffing Position During Video Laryngoscopy in Predicted Difficult Airway

The left head rotation (LeHeR) maneuver, in which the head of the supine patient is rotated 45° to the left, is a simple, equipment-free technique proposed to improve the laryngeal view. Studies using the Percentage of Glottic Opening (POGO) score during video laryngoscopy have reported improvement with LeHeR, but evidence is limited and the maneuver has not been systematically evaluated in patients with a predicted difficult airway. This prospective, observational, self-controlled study aims to compare the POGO score obtained in the sniffing position with that obtained in the 45° LeHeR position in the same adult patients with a modified El-Ganzouri Risk Index (EGRI) score above 4 undergoing elective surgery under general anesthesia with video laryngoscopy. Ease of intubation, number and duration of attempts, need for adjuvant maneuvers, hemodynamic changes, and airway trauma will also be recorded.

Comparison of Two Sedation Regimens for Awake Fiberoptic Intubation

The purpose of this study is to examine the effects of different sedation drugs used for the awake fiberoptic intubation procedure. Benzodiazapines and narcotics (such as midazolam and fentanyl) are standard drugs used for sedation during awake fiberoptic intubation. Dexmedetomidine, midazolam, and fentanyl are approved by the Food and Drug Administration (FDA) procedural sedation. These drugs might be given to the patient regardless of their participation in the study. In addition to midazolam and fentanyl study subjects will also receive either dexmedetomidine or a placebo (a salt solution that contains no drug). It is believed that dexmedetomidine will not slow down breathing as much as the combination of the valium-like drug and narcotic. In our study, we are trying to determine if this is the best drug for sedation during an awake fiberoptic procedure.

Determination of the Frequency and Predictors of Difficult Intubation in Septoplasty Operations

Deviated septum is among the most prevalent etiologies of nasal obstruction. Congenital or acquired deformities of the nasal septum have been demonstrated to result in partial obstruction of the airflow, thereby causing respiratory distress. Furthermore, studies have indicated a potential correlation between nasal congestion and Obstructive Sleep Apnoea Syndrome (OSAS). It is a well-documented phenomenon that patients suffering from nasal obstruction often exhibit an open mouth during sleep, a condition that has been shown to result in the narrowing of the pharyngeal lumen and the subsequent development of sleep-related breathing disorders, including snoring and sleep apnoea. Surgical intervention to correct a deviated nasal septum (commonly referred to as septoplasty) has been shown to reduce upper airway resistance by enhancing airflow, leading to a reduction in the severity of both snoring and OSAS. Numerous studies have demonstrated a robust correlation between a deviated nasal septum and asymmetric facial growth, including maxillary and mandibular abnormalities. While septoplasty is considered a minor surgical procedure with a low anaesthetic risk, concomitant obstructive sleep apnoea syndrome (OSAS) and facial asymmetry have been demonstrated to be associated with an increased risk of difficult intubation. Consequently, the development of preoperative assessment tests to predict difficult intubation is imperative for effective planning of the necessary preoperative preparation when such complications are anticipated. The present study therefore sought to evaluate the incidence of difficult airway in patients undergoing septoplasty. The secondary aim was to determine the predictive factors associated with difficult airway in patients undergoing septoplasty.

Airway Ultrasound vs Clinical Predictors for Difficult Airway

This prospective observational study aims to evaluate the diagnostic value of airway ultrasonography in predicting difficult intubation in adult patients undergoing elective surgery under general anesthesia. Preoperative sonographic measurements of upper airway structures will be compared with conventional clinical airway assessment parameters such as the Mallampati score, thyromental distance, and sternomental distance. The study seeks to determine whether ultrasonographic measurements can serve as independent predictors of difficult airway and whether combining them with clinical parameters improves diagnostic accuracy. Additionally, the correlation between sonographic findings and the Intubation Difficulty Scale (IDS) will be analyzed to assess the potential clinical utility of airway ultrasound in preoperative airway evaluation.

Correlation Between Bedside Anatomical Indicators and Lifting Force and Glottic Exposure Under Different Video Laryngoscopy Techniques

This single-center prospective observational study plans to enroll 196 patients undergoing elective general anesthesia. The study aims to investigate the correlation between preoperative bedside anatomical indicators (including modified Mallampati classification, upper lip bite test, mouth opening, head circumference, and thyromental distance) and the peak lifting force applied during video laryngoscopy, as well as the degree of glottic exposure (POGO score). The study will also evaluate the potential benefit of the direct epiglottis elevation technique in specific anatomical subgroups. After anesthesia induction, the same anesthesiologist will perform video laryngoscopy using two distinct techniques in a fixed sequence: the indirect (vallecula) method and the direct (subepiglottic) method. Peak lifting force will be quantitatively measured in real-time using a resistive thin-film pressure sensor attached to the laryngoscope blade. The primary outcomes are the POGO scores and peak lifting forces under both techniques. The secondary outcome includes the change in POGO score (ΔPOGO) between techniques. The study will provide quantitative evidence regarding the "anatomy-force-view" relationship and aid in individualized clinical decision-making for video laryngoscopy intubation.

Predicting Difficult Intubation in Bariatric Surgery: Comparison of El Ganzouri Risk Index and Airway Ultrasound

This study is designed as a prospective observational study and will be conducted at the Health Sciences University Antalya Training and Research Hospital. Adult patients scheduled to undergo bariatric surgery will be included. The aim of this study is to compare the El Ganzouri Risk Index (EGRI) and airway ultrasonography (USG) parameters in predicting difficult intubation and to evaluate their relationship with the Cormack-Lehane (CL) score obtained during direct laryngoscopy. Before surgery, each participant will be evaluated using both the EGRI scoring system and airway USG. During general anesthesia, tracheal intubation will be performed using direct laryngoscopy, and data including the CL score, intubation time, number of attempts, and the need for videolaryngoscopy will be recorded based on the anesthesiologist's observations. The collected data will be analyzed by classifying participants according to the presence or absence of difficult intubation, and statistical comparisons will be performed between EGRI scores and airway ultrasonography parameters. The results of this study may contribute to improved preoperative airway assessment and enhanced patient safety in bariatric surgery.

Comparative Analysis of a Preoperative Airway Ultrasound Protocol and Direct Laryngoscopy in Oncologic Surgery Patients

This prospective observational study evaluated the predictive performance of the Difficult Airway Evaluation with Sonography (DARES) protocol for identifying difficult laryngoscopy and other airway management difficulties in adult patients undergoing elective oncologic surgery. Preoperative airway ultrasonography was performed together with conventional clinical airway assessment. Ultrasound parameters included the distance from skin to epiglottis (DSE), hyomental distance (HMD) measured in different head positions, hyomental distance ratios (HMDR1 and HMDR2), and tongue thickness (TT). Conventional airway assessment parameters were also recorded. The primary objective was to evaluate the ability of ultrasound-derived airway parameters to predict difficult laryngoscopy, defined as a Cormack-Lehane grade \>2a (grades 2b, 3, or 4) during direct laryngoscopy, and to compare their predictive performance with conventional clinical airway assessment methods. Secondary objectives included evaluating the relationship between ultrasound parameters and difficult mask ventilation, assessed using the Han scale; investigating their relationship with difficulties or complications encountered during extubation; and exploring differences in airway ultrasound parameters and their predictive performance across oncologic patient subgroups.

Hyperangulated Video Laryngoscopes Used for Intubation With Simultaneous Cervical Spine Immobilization

This study will evaluate four videolaryngoscopes used for intubation of patients with cervical spine immobilization. Two hundred adult patients (females and males) with ASA (American Society of Anesthesiologist) status 1-3 will be scheduled for elective laparoscopic surgery at the Mazowiecki Szpital Specjalistyczny in Radom, Poland. Patients with known difficult laryngoscopy, difficult face mask ventilation, with previous history of awake tracheal intubation, those aged under 18 years or patients with BMI \> 30 kg m-2 will be excluded from the study. All patients will receive oral premedication with 7.5 mg midazolam 30 minutes before the start of anaesthesia. A standard monitoring will be applied. This consists of ECG, NIBP (non-invasive blood pressure), SpO2, TOF (train-of-four) and volatile anaesthetic concentration. In order to achieve cervical spine immobilization, a Patriot® cervical collar (Össur hf., Reykjavik, Iceland) will be applied. The size of the collar will be adjusted to the patient's anatomy. Furthermore, the cervical collar will be fixed to allow a minimal mouth opening of 20 mm. All patients will be placed in a neutral position and will be pre-oxygenated with FiO2 1.0 for three minutes prior to induction. Anaesthesia will be induced with fentanyl (1-2 µg ml-1) and propofol (2-3 mg ml-1). Rocuronium (0.6 mg ml-1) will be used as a neuromuscular blocking agent. Adequate neuromuscular block will be confirmed and controlled throughout the procedure with TOF Watch (Organon, Dublin, Ireland). A cuffed, size 7.5 tracheal tube with stylet (Sumi, Sulejówek, Poland) will be used for intubation. A single-use hyperangulated blade will be used in all studied devices. Correct placement of the tracheal tube will be confirmed by videolaryngoscopy, capnography and chest auscultation. All patients will be anaesthetised by experienced consultant anaesthetists with over 10 years of clinical practice after completion of specialist training. Furthermore, all anaesthetists participating in the study will be trained beforehand with all VLs used until they feel competent. Only two intubation attempts with a studied videolaryngoscope will be allowed. A single attempt will be limited to 60 seconds. A failure is defined as an attempt which lasts more than 60 seconds, when saturation drops below 90%, after two unsuccessful attempts, when airway injury or bronchospasm occurrs. A single-digit number will be allocated to each of the studied videolaryngoscopes: 1 for the C-MAC PM, 2 for the McGrath, 3 for the VisionPro and 4 for the AceScope. A single sheet of paper containing printed number will be placed in an opaque envelope. Then they will be assigned to the participating anaesthetist by computer-generated randomization. The SPSS 29.0 software (IBM, Armonk, NY, USA) will be used for allocation. Furthermore, patients will be blinded to randomization.

Novel Integrated Tube-Bougie Prototype for Endotracheal Intubation in Airway Simulation

Endotracheal intubation is a critical airway management procedure that frequently requires adjunctive devices, such as stylets or elastic bougies, to facilitate successful tube placement. Although videolaryngoscopy has become increasingly common, access to videolaryngoscopes remains limited in certain clinical settings, particularly in prehospital and resource-constrained environments. Consequently, stylets and bougies continue to play an essential role in airway management. To address this need, we developed a novel integrated tube-bougie prototype that combines the guidance function of an elastic bougie with an endotracheal tube into a single device. This prospective, randomized, crossover simulation study is designed to compare the performance of the integrated tube-bougie prototype with conventional stylet-assisted and elastic bougie-assisted endotracheal intubation. Emergency medicine residents will perform intubations using all three techniques in both normal and difficult airway simulation scenarios according to a randomized crossover sequence. The primary outcome is the time to successful endotracheal intubation. Secondary outcomes include first-attempt intubation success, perceived procedural difficulty assessed using a visual analog scale (VAS), incidence of esophageal intubation, dental trauma, and evaluation of the learning curve using cumulative sum (CUSUM) analysis. The findings could contribute to the development of alternative airway assistive equipment for emergency airway management and training.

SEALion: Study on Supplemental Oxygenation Via Nasal Cannula for Young Children During Intubation

Tracheal intubation in neonates can be technically challenging, even for experienced pediatric anesthesiologists, with a high first-attempt success rate crucial to ensure safety. Intubation, while life-saving for children with circulatory shock or respiratory failure, carries risks of severe desaturation that can lead to hypoxic encephalopathy, cardiac arrest, or death. Neonates, especially, are prone to hypoxemia due to high oxygen consumption, low functional residual capacity, small closing capacity, and increased risk of airway collapse, which is exacerbated under anesthesia and neuromuscular paralysis. Rapid desaturation occurs after cessation of ventilation, with neonates facing shorter apnea times before desaturation. Studies show that about two-thirds of neonates undergoing non-emergency nasotracheal intubation experience desaturation (SpO₂ \<80% for over 60 seconds), although low-flow oxygen supplementation (0.2 L/kg/min) can extend safe apnea time. This study aims to investigate apneic oxygenation with VL (using Miller or Macintosh blades size 0 or 1) in operating rooms or intensive care units. We hypothesize that supplemental oxygen and standardized VL use will improve first-pass success rates and reduce adverse events.

High-flow Nasal Cannula Versus Conventional Oxygen During Awake Tracheal Intubation With Difficult Airways

Study Background Airway management is one of the most fundamental and critical technical procedures in anesthesiology, critical care, and emergency medicine. Difficult airway management remains a major challenge in these fields, particularly when a "cannot intubate, cannot ventilate" scenario occurs during the induction of general anesthesia. Such events can rapidly lead to hypoxemia, resulting in brain injury or even death, and have become a significant source of anesthesia-related severe complications and medical disputes. Awake tracheal intubation (ATI) is considered the gold standard for airway management in patients with anticipated difficult airways, as it preserves spontaneous breathing and thereby reduces the risk of catastrophic airway failure during anesthesia induction. However, despite routine supplemental oxygen administration, hypoxemia remains one of the most common and potentially serious complications during ATI. When low-flow oxygen therapy (\<30 L/min) is used, the reported incidence of hypoxemia (SpO₂ ≤ 90%) ranges from 12% to 29%. Once hypoxemia occurs during ATI, it may not only interrupt the procedure, increase the number of intubation attempts, and reduce the likelihood of successful intubation, but also trigger serious cardiovascular events, thereby compromising patient safety. High-flow nasal cannula (HFNC) oxygen therapy can deliver heated and humidified gas at flow rates of up to 70 L/min and improve oxygenation and ventilation through mechanisms such as anatomical dead space washout, reduction of work of breathing, and generation of continuous positive airway pressure. HFNC has been shown to improve oxygenation in a variety of medical and procedural settings. However, evidence regarding the role of HFNC during awake tracheal intubation remains controversial and of low quality. There is an urgent need for well-designed multicenter randomized controlled trials specifically focused on the ATI setting, using hypoxemic events as the primary outcome and applying strictly standardized procedures, to provide high-quality evidence on the effectiveness and safety of HFNC during ATI. Such evidence is essential to inform clinical practice and support future updates of airway management guidelines. Study Hypothesis This study hypothesizes that, in patients with anticipated difficult airways undergoing ATI, HFNC is more effective in preventing intubation-related hypoxemic events than conventional low-flow nasal cannula oxygen therapy. Study Objectives Primary Objective: To evaluate the effectiveness of high-flow nasal cannula oxygen therapy compared with conventional low-flow nasal cannula oxygen therapy in preventing hypoxemia during ATI in patients with anticipated difficult airways. Secondary Objectives: To assess the effects of high-flow nasal cannula oxygen therapy versus conventional low-flow nasal cannula oxygen therapy on procedural outcomes of awake tracheal intubation, including the rate of interventions required after hypoxemia, first-attempt intubation success rate, number of intubation attempts, overall ATI success rate, intubation time, and the incidence of adverse events. Study Methods This study is a multicenter, randomized controlled clinical trial. Adult patients undergoing ATI will be recruited from six tertiary hospitals in China. Participants will be randomly assigned to receive either high-flow nasal cannula oxygen therapy or conventional low-flow nasal cannula oxygen therapy throughout the intubation procedure. The study will compare the incidence of hypoxemia between the two groups and further evaluate intubation success rates, intubation time, the need for rescue interventions following hypoxemia, and the incidence of adverse events.

Ultrasonographic Airway Assessment and VIDIAC Score

This prospective observational study aims to evaluate the relationship between preoperative ultrasonographic airway measurements and the Video-Intubation Difficulty Assessment Classification (VIDIAC) score in adult patients undergoing endotracheal intubation under general anesthesia. The study will investigate whether airway ultrasound parameters can predict difficult videolaryngoscopic intubation and assess their association with the Cormack-Lehane classification, intubation time, and other airway management outcomes.

Airway Ultrasound and PeDiAC Score in Pediatric Patients

This prospective observational study aims to evaluate the relationship between preoperative ultrasonographic airway measurements and the Pediatric Difficult Airway Classification (PeDiAC) score in pediatric patients undergoing general anesthesia. The study will assess whether ultrasound-derived airway parameters are associated with difficult airway characteristics and PeDiAC scores.

The Impact of Ultrasound Measurements in Predicting Difficult Airway on Videolaryngoscopy Success

In this preoperative observational study, the effect of preoperative ultrasonographic measurements on the success of videolaryngoscopy in predicting difficult airways was investigated; furthermore, the aim was to determine new cut-off values that can predict difficult intubation in videolaryngoscope use. In our study, it was tested that the use of videolaryngoscope significantly increased the success of intubation in patients who were assessed as having difficult airways with upper airway ultrasound measurements.

Mental Rehearsal in Emergency Cricothyroidotomy Training

Medical staff at the clinic will participate in standard cricothyroidotomy training supplemented with structured mental rehearsal exercises in order to evaluate the usefulness and effectiveness of this approach as a training tool.

Effect Of Left Head Rotation On Glottic View During Video Laryngoscopy In Obese Adults

This study aims to evaluate whether the Left Head Rotation (LeHeR) maneuver improves visualization of the vocal cords during video laryngoscopy in obese adult patients undergoing general anesthesia. Obesity is associated with increased difficulty in airway management due to excess upper airway soft tissue and altered anatomy, which may impair visualization during intubation. In this prospective observational study, 50 adult patients with a body mass index (BMI) ≥30 kg/m² will undergo video laryngoscopy using a C-MAC D-blade. The glottic view will be assessed using the Percentage of Glottic Opening (POGO) score in the standard sniffing position and after rotating the head 45 degrees to the left (LeHeR maneuver). A difference in POGO score between the two positions will be analyzed. Secondary outcomes include ease of intubation, number of attempts, time to successful intubation, and occurrence of complications such as desaturation or airway trauma. The study is expected to determine whether the LeHeR maneuver is a simple and effective technique to improve airway visualization in obese patients.

Effect of High-Flow Nasal Oxygen on Laryngoscopic View

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.

Ultrasound Airway Examination as a Tool for Detection of Difficult Intubation in Adult Patients

the goal of the observational study to measure the effectiveness of neck ultrasound in prediction of difficult intubation in adult patients

TMH And Ultrasound For Difficult Airway Prediction

This prospective observational study aims to evaluate the predictive value of thyromental height (TMH) and ultrasonographic airway measurements in predicting difficult airway in adult patients undergoing elective surgery under general anesthesia. Preoperative airway assessment will include standard clinical evaluation, TMH measurement, and ultrasonographic measurements of anterior neck soft tissue. Perioperative airway management data, including intubation difficulty, number of attempts, and Cormack-Lehane classification, will be recorded. The relationship between preoperative measurements and difficult airway will be analyzed to determine their predictive accuracy and clinical usefulness.

Ultrasound vs Clinical Parameters for Difficult Airway Prediction in Obesity

Obesity is associated with anatomical changes in the upper airway that increase the risk of difficult laryngoscopy and difficult mask ventilation during anesthesia. Conventional airway assessment parameters such as Mallampati score, neck circumference, and STOP-BANG scale are widely used but have limited predictive accuracy in obese patients. Airway ultrasonography has emerged as a promising non-invasive tool for difficult airway prediction; however, ultrasonographic criteria have not yet been standardized. This prospective observational study aims to evaluate the utility of airway ultrasonography in predicting difficult airway in adult obese patients (BMI \>30 kg/m²) scheduled for elective surgery under general anesthesia. Ultrasonographic measurements will include the distance from skin to hyoid bone (DSHB) at the level of the hyoid bone, the anterior neck soft tissue thickness at the thyrohyoid membrane level, and the hyomental distance ratio (HMDR). These parameters will be compared with conventional airway assessment tools and correlated with intraoperative Cormack-Lehane laryngoscopy grade and Han Scale mask ventilation score to determine their predictive value for difficult airway.

Comparative Study Between Combined Video Laryngoscope and Video Stylet Intubation Versus Combined Video Laryngoscope and Fiberoptic Intubation in a Simulated Difficult Airway

This study titled "Comparative Study Between Combined Video Laryngoscope and Video Stylet Intubation Versus Combined Video Laryngoscope and Fibreoptic Intubation in a Simulated Difficult Airway" aims to evaluate and compare two advanced intubation techniques used in managing difficult airways. Currently, there is no study in Malaysia that compares the combination of a video laryngoscope (VL) with a video stylet (VS) and the combination of VL with a fibreoptic bronchoscope (FOB). Although both methods have been investigated separately, direct comparisons in simulated difficult airway settings are limited. The findings of this study will help guide airway management protocols and improve clinical outcomes in challenging airway situations. This is a single-centre, randomized comparative crossover trial conducted at the Department of Anaesthesiology and Intensive Care, HCTM, UKM. Ethical approval will be obtained from the departmental and university ethics committees prior to commencement. The study population will consist of anaesthesiology medical officers with at least two years of experience and anaesthesiology trainees in their second to fourth year of training at HCTM, UKM. Participants with severe hand tremors or those who decline participation will be excluded. The main objectives are to compare the first-pass intubation success rate, time to successful intubation, and operator-rated ease of intubation between the two combined techniques. Each participant will perform both VL with VS and VL with FOB intubations in a simulated difficult airway scenario. The study hypothesizes that the combined VL with VS technique will provide superior performance, a higher first-pass success rate, shorter intubation time, and greater ease of use compared to the VL with FOB technique. Participants who fail to complete all procedures or withdraw after participation will be considered dropouts. The results from this study are expected to provide useful insights into the effectiveness and practicality of these two combination techniques for airway management training and clinical application.

Difficult Airway Incidence in Cardiovascular Surgery and a Prediction Model Development

A difficult airway is a clinical condition that occurs when one or more of the components of difficult mask ventilation, difficult laryngoscopy, difficult endotracheal intubation, difficult supraglottic airway device (SGA) placement, and inability to intubate-oxygenate are present. Data concerning incidence of difficult airway in patients undergoing cardiovascular surgery is controversial. Unwanted hemodynamic changes that may occur in patients undergoing cardiovascular surgery, combined with hemodynamic changes caused by underlying cardiac pathologies, may also lead to a physiologically difficult airway situation. Since all these interactions, combined with the hemodynamic changes caused by difficult airway interventions, may lead to catastrophic outcomes, it is vital to predict difficult airway in this patient population.

Validation of End-to-End Difficult Airway Pathway Planning Algorithm (EAP-LC)

Patients with laryngeal cancer often present with varying degrees of airway narrowing or anatomical distortion, making airway management particularly challenging. Awake flexible bronchoscopic intubation is a widely accepted and important strategy to ensure airway safety in this population. Currently, the selection of the intubation pathway mainly relies on visual assessment of preoperative computed tomography (CT) images and the clinical experience of anesthesiologists, lacking objective and quantifiable tools for airway pathway planning. Our research group has developed an end-to-end airway pathway planning algorithm for laryngeal cancer patients (EAP-LC), which can automatically generate predicted nasal or oral intubation pathways based on preoperative pharyngeal and upper airway CT images. Preliminary simulation analyses based on retrospective CT data demonstrated that the algorithm is capable of identifying airway narrowing and generating trajectories that are close to clinically feasible intubation paths (preliminary data, under review). However, to date, no study has directly compared the algorithm-predicted pathways with actual intubation trajectories obtained during awake flexible bronchoscopic intubation. Therefore, a prospective clinical validation study is required to evaluate the spatial consistency and clinical feasibility of the EAP-LC algorithm. Without altering routine clinical treatment or anesthetic management, this study aims to evaluate the clinical accuracy, safety, and feasibility of the EAP-LC algorithm by comparing the intubation pathways predicted from preoperative CT images with the real-world trajectories recorded during awake flexible bronchoscopic intubation. The results of this study are expected to provide a more precise and objective decision-support tool for airway management in patients with laryngeal cancer.

AI-based Prediction Model of Difficult Tracheal Intubation Using Medical Image Parameters

Difficult airway is a life-threatening event during anesthesia. Prediction model is helpful to detect high-risk patients and decrease the risk of un-anticipated difficult airway. Present models are usually based on Mallampati grade and the width of mouth open. However, the prediction accuracy is only about 0.7-0.8 in different populations. Present study is designed to investigate if AI-based prediction model using medical imaging parameters (such as CT and MRI) can increase the accuracy of prediction model.