Effect of Head and Neck Positioning on Awake Fiberoptic Intubation in Obese Patients

Airway management in patients undergoing general anesthesia is a set of actions that result in the creation of a safe and secure airway for ventilation. Failure in airway management and hypoxia can lead to irreversible brain damages within only a few minutes .

The prevalence of obesity is rising worldwide, and this is a challenge for specialists in various fields of medicine. There is an inverse correlation between body weight and pharyngeal space. This association is significant because excess fat in morbid obesity can influence the pharyngeal spaces, and thus, significantly change laryngoscopic grade . Overall, airway management in obese patients can pose numerous challenges as these patients are at a higher risk for difficult airway than normal patients . In fact, patients with morbid obesity have excess fat in the mouth, neck, pharynx, thorax, breast, and abdomen, making access to the airway more problematic in various anesthesia situations such as intubation, tracheostomy, or mask ventilation as compared to normal subjects. In most studies, an increase in neck circumference was associated with difficult intubation, and a neck circumference over 60 cm was linked with a 35% likelihood of difficult intubation. Hence, the possibility of difficult intubation and problems with difficult airways in these patients should be considered, and a solution should be provided. In dealing with difficult airways, assistive devices such as fiberoptic bronchoscope and video-laryngoscope may be used in either awake or anesthetized patients .

Proper positioning before the induction of anesthesia is a key step in successful intubation . Numerous studies have emphasized the significance of head and neck positioning, which can have a significant impact on successful intubation and reduce tracheal injury and post-intubation complications .

The aim of the study was the assessment and comparison of the time taken for vocal cord visualization with three different head positions: (conventional sniffing position, ramp position and supine position) in obese patients

Group (S) Sniffing position : All patients will be explained the procedure on the day of surgery. Intravenous access will be gained a 16 through gauge cannula under local anesthesia. Standard monitoring (pulse oximeter, electrocardiography, non-invasive blood pressure) will attach to the patients. The patient's airway will be anesthetized using aerosolized lignocaine 2%.

The oral and pharyngeal reflexes will be blunted by anesthetizing oral and pharyngeal mucosa with 10% lignocaine spray and gargles.

Procedure: Group (S) Sniffing position

Group (R) Ramped position: patients will be explained the process. Intravenous access will be gained and standard monitoring will be attached to the patients. The patient's airway will be anesthetized. After this, the patients will be helped to assume a ramped position. Three soft pillows will be positioned beneath the patient's head and upper body so that the external auditory meatus will be in a horizontal plane with a sternal notch.

Procedure: Group (R) Ramped position

Group (SU) Supine position: All Group SU patients were explained the procedure on the day of surgery. Intravenous access was gained through a 16-gauge cannula under local anesthesia. Standard monitoring (pulse oximeter, electrocardiography, non-invasive blood pressure) was attached to the patients. The patient's airway was anesthetized using aerosolized lignocaine 2%. The oral and pharyngeal reflexes were blunted by anesthetizing oral and pharyngeal mucosa with 10% lignocaine spray and gargles.

Procedure: Group (SU) Supine position

Group (S) : patients will be explained the procedure on the day of surgery. Intravenous access will be gained a 16 through gauge cannula under local anesthesia. Standard monitoring (pulse oximeter, electrocardiography, non-invasive blood pressure) will attach to the patients. The patient's airway will be anesthetized using aerosolized lignocaine 2%.

The oral and pharyngeal reflexes will be blunted by anesthetizing oral and pharyngeal mucosa with 10% lignocaine spray and gargles. The sniffing position will be made by placing 8 cm ring pillow under the patient head so that it will be tilted. The external auditory meatus will be aligned the sterna notch in the horizontal plane. The elevation of the operating and position of the anesthesiologist will be adjusted to ensure that the fiber-optic will be kept straight as it entered the patient's nasal cavity. The appropriate-sized endotracheal tube will be loaded over a 5mm external diameter flexible fiberoptic bronchoscope. Preoxygenation w

Group (R) Ramped position On the day of the operation, all Group R patients will be explained the process. Intravenous access will be gained and standard monitoring will be attached to the patients. The patient's airway will be anesthetized. After this, the patients will be helped to assume a ramped position. Three soft pillows will be positioned beneath the patient's head and upper body so that the external auditory meatus will be in a horizontal plane with a sternal notch. The elevation of the operating and position of the anesthesiologist will be adjusted to ensure that the fiber-optic was straight as it entered the patient's nasal cavity. An appropriately sized endotracheal tube will be loaded over a 5mm external diameter flexible fiberoptic bronchoscope. Preoxygenation will be performed with 100% oxygen with tidal volume ventilation for three to five minutes to achieve an end-expiratory oxygen concentration greater than 90%.

Group (SU) Supine position: patients were explained the procedure on the day of surgery. Intravenous access was gained through a 16-gauge cannula under local anesthesia. Standard monitoring (pulse oximeter, electrocardiography, non-invasive blood pressure) was attached to the patients. The patient's airway was anesthetized using aerosolized lignocaine 2%. The oral and pharyngeal reflexes were blunted by anesthetizing oral and pharyngeal mucosa with 10% lignocaine spray and gargles. The elevation of the operating and position of the anesthesiologist will be adjusted to ensure that the fiber-optic was kept straight as it entered the patient's nasal cavity. The appropriate-sized endotracheal tube will be loaded over a 5mm external diameter flexible fiberoptic bronchoscope. Preoxygenation will be performed with 100% oxygen with tidal volume ventilation for three to five minutes to achieve an end- expiratory oxygen concentration greater than 90%.

Time frame: 1 hour

Assessment and comparison of the time taken for vocal cord visualization with three different head positions: (conventional sniffing position, ramp position and supine position) in obese patients.

Time frame: 1 hour

Cough score for fiberoptic and for intubation (score range: 0 = none, 1 = slight, 2 = moderate, 3 = severe)

Effect of Head and Neck Positioning on Awake Fiberoptic Intubation in Obese Patients: A Randomized Controlled Study