Effect of Head Rotation on Efficacy of Face Mask Ventilation in Anesthetized Obese (BMI ≥ 35) Adults

Study Overview
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Brief Summary
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Mask ventilation is fundamental to airway management at the start of surgical procedures requiring general anesthesia. For general anesthesia, medications are provided that affect the entire body and lead to a loss of consciousness. Medical professionals perform mask ventilation by placing a plastic mask over a subjects mouth and nose to provide enough oxygen for the placement of a breathing tube. In this study, we expect that a 45 degree rotation of the head will increase the efficiency of mask ventilation.

Detailed Description
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Mask ventilation is a foundation of airway management after the initial induction of anesthesia. It allows for adequate oxygenation of the patient to buy enough time for intubation, during which the patient is not ventilated. However, in some patients mask ventilation may be difficult - older than 55 years, heavier (BMI > 26 kg/m^2), with no teeth, having a beard or sleep apnea. Inadequate ventilation, if not corrected, can result in decreasing oxygen saturation to dangerous levels - which could lead to devastating complications. As a result, the efficacy of mask ventilation is of critical importance to patient safety after the induction of anesthesia. A recent study proposed that mask ventilation could be improved simply by turning a patient's head. The study showed that rotating a patient's head to a 45 degree angle significantly improved mask ventilation when compared with the head placed in a neutral position. However, this study was done in patients with a BMI lass than 35. As such, the effects of head rotation on the efficacy of mask ventilation has not been studied in patients with a BMI of 35 and greater. Obesity (BMI ≥ 30 kg/m^2) affects almost 40% of US adults and is one of the most prevalent health concerns in our society. It is a predictor of difficult mask ventilation because it is associated with increased upper airway obstruction, decreased airway patency, and decreased lung volumes such as functional residual capacity (FRC). If previous findings in regard to the effects of 45 degree head rotation on the efficacy of ventilation hold true in the obese patient, then this study will show that head rotation could be used as a simple way to improve the efficacy of mask ventilation for patients with a BMI of 35 and above.

Official Title
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A Prospective, Randomized, Non-Blinded, Crossover Controlled Clinical Trial Evaluating the Efficacy of Face Mask Ventilation With 45 Degree Head Rotation in Anesthetized Obese (BMI ≥ 35) Adults

Conditions
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Noninvasive Ventilation

Intervention / Treatment
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* Procedure: Head Rotation During Face Mask Ventilation
* Device: Medline Top Valve Anesthesia Mask


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Age ≥ 18 years ASA Physical Status Classification I-III Body Mass Index (BMI) ≥ 35 kg/m^2 Exclusion Criteria: Inability to obtain written informed consent Pregnant or breastfeeding Limited head rotation or neck extension Subjects with expected or history difficult intubation Large beard Orogastric (OG)/nasogastric (NG) tube Gastroesophageal Reflux Disease (GERD)

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Crossover Assignment
Interventional Model Description: Participants will be assigned into one of two groups (per a randomization schedule) for face mask ventilation. The sequence of face mask ventilation head positions will be determined by group assignment. Each position will be performed for one minute. Group A: (1) neutral position, (2) head rotation, (3) neutral position. Group B: (1) head rotation, (2) neutral position, (3) head rotation.
Masking: Triple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Group A<br>Head Rotation During Face Mask Ventilation. Step 1: Neutral Position (1 minute), Step 2: Head Rotation (1 minute), Step 3: Neutral Position (1 minute) | Procedure: Head Rotation During Face Mask Ventilation<br>* Participants will receive face mask ventilation in either a neutral head position (practice standard position) or a head rotation position (45 degree angle).<br>Device: Medline Top Valve Anesthesia Mask<br>* Face mask used per standard of care to provide oxygen to subjects before surgical procedures.<br>* Other names: Face Mask;|
| Experimental: Group B<br>Head Rotation During Face Mask Ventilation. Step 1: Head Rotation (1 Minute), Step 2: Neutral Position (1 minute), Step 3, Head Rotation (1 Minute) | Procedure: Head Rotation During Face Mask Ventilation<br>* Participants will receive face mask ventilation in either a neutral head position (practice standard position) or a head rotation position (45 degree angle).<br>Device: Medline Top Valve Anesthesia Mask<br>* Face mask used per standard of care to provide oxygen to subjects before surgical procedures.<br>* Other names: Face Mask;|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximal and average expiratory tidal volume during mask ventilation | Measured in mL | Day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Maximal and average inspiratory tidal volume during mask ventilation | Measured in mL | Day 1 | 
| Maximal and average end-tidal CO2 (ETCO2) during mask ventilation | Measured in mm Hg | Day 1 | 
| Maximal and average airway flow during mask ventilation | Measured in L/min | Day 1 | 
| Lowest and delta O2 saturation drop on SpO2 during mask ventilation | Measured in % | Day 1 | 
| Lowest and delta O2 saturation drop on SpO2 during intubation | Measured in % | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Face Mask, Obesity, Anesthetized Adult, Ventilation, Head Rotation