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

November 4, 2026 updated by: Amr Raafat Mahmoud Seif, Cairo University

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

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

Study Overview

Status

Enrolling by invitation

Conditions

Intervention / Treatment

Detailed Description

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

Study Type

Interventional

Enrollment (Estimated)

60

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

      • Cairo, Egypt
        • Cairo University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

18 years to 60 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Age between 18 to 60 years old
  • Body mass index more than 40 kg/m
  • Potentially difficult intubation defined as mallampatti classification greater than two and neck circumference more than 40 cm

Exclusion Criteria:

  • Age younger than 18 and more than 60 years old
  • American Society of Anesthesiologists clinical status is more than four
  • Sever mental disorder (psychotic or consider incapable of understanding the information)
  • Mouth opening is less than 15 mm
  • Poor dental status
  • Contraindication to any drug used in the study
  • patient refusal.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Prevention
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Group (S) Sniffing position

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.

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

Experimental: Group (R) Ramped 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.

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%.

Experimental: Group (SU) Supine 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.

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%.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
comparison of the time taken for vocal cord visualization
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.

1 hour

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cough score for fiberoptic and for intubation
Time Frame: 1 hour

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

1 hour

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

September 30, 2026

Primary Completion (Estimated)

September 30, 2027

Study Completion (Estimated)

September 30, 2027

Study Registration Dates

First Submitted

November 4, 2026

First Submitted That Met QC Criteria

November 4, 2026

First Posted (Actual)

November 10, 2026

Study Record Updates

Last Update Posted (Actual)

November 10, 2026

Last Update Submitted That Met QC Criteria

November 4, 2026

Last Verified

September 1, 2026

More Information

Terms related to this study

Other Study ID Numbers

  • AP2609-501-179-213

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

It will be available if it needed

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

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