Effectiveness of Two Different Body Positions During Facemask Ventilation in Obese Patients

Effectiveness of Two Different Body Positions During Facemask Ventilation in Class 3 Obesity Patients: a Randomized Crossover Trial

It is important to provide enough oxygen to the patients who are asleep during surgery. One way to do this is by using a mask placed over the face to help them breathe. When it becomes difficult getting enough oxygen into the patient's body using the mask, it's called difficult mask ventilation. There can be different reasons for this, and having a higher BMI is one of them. Body physique is assessed by Body Mass Index (BMI). This calculation gives an indication of a person's weight relative to their height.

There is some evidence in the research literature to suggest that when the patient is positioned in a way that helps their airway, like using a device to lift their head and torso 25 degrees , it might help the process of getting enough oxygen work better. The study aims to determine if patients with high BMI can breathe better using a face mask while they are in a head elevated position compared to lying flat on their back.

Study Overview

• Status: Not yet recruiting
• Conditions: Obesity
• Intervention / Treatment: Other: Head position for face mask ventilation during induction supine; Other: Head position for face mask ventilation during induction head elevated

Detailed Description

Facemask ventilation is an important technique applied by anesthesiologists after induction of general anesthesia and before tracheal intubation. It is also used as a rescue maneuver in situations where a patient's consciousness is compromised affecting oxygenation. Obesity is well known to be one of the difficult predictors for facemask ventilation. In fact, the occurrence of difficult facemask ventilation is more frequent in obese patients than non obese. One of the maneuvers described to optimize the effectiveness of facemask ventilation in the general population is positioning the patient in a 25 degree head elevated position. A previous study has demonstrated improvement in facemask ventilation in obese patients with BMI from 30 to 40 kg/m2 in the head elevated position, compared to supine. However, it is not yet determined if this is applicable to patients with a BMI above 40 kg/m2. Adult obese patients with BMI of at least 40 kg/m2 will be randomized to be ventilated after induction of general anesthesia via a face mask while in one of the positions: supine or head elevated, while the volume of air that enters and exits the lungs is measured. Participants will then be changed to the second position, ventilated in the same manner and measures obtained again.

Do patients with class 3 obesity positioned in the head elevated position can be better ventilated with a face mask and positive pressure, compared to the supine position?

• Study Type: Interventional
• Enrollment (Estimated): 38
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Fabricio Zasso, MD; Phone Number: 416-586-4800; Email: Fabricio.Zasso@sinaihealth.ca

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• BMI > 40 kg/m2
• age > 18 years
• scheduled for elective surgery under general anesthesia
• have the ability to comprehend the rationale for the study and provide consent

Exclusion Criteria:

• pregnancy,
• risk of aspiration of gastric content
• patients using glucagon-like peptide(GLP)-1 agonists
• emergency cases
• upper airway disease or airway anatomical abnormalities
• presence of major cardiovascular, respiratory, or cerebral vascular disease
• if the provider anesthesiologist indicates an awake technique to secure the airway

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Supine; Participant will be ventilated with facemask while in supine position.	Other: Head position for face mask ventilation during induction supine; Participant to be ventilated starting 2 minutes after induction of general anesthesia via a face mask while in supine position. Participants will be crossed over to the head elevated position after the first measurement is obtained.
Experimental: Head elevated; Participant will be ventilated with facemask while in head elevated position.	Other: Head position for face mask ventilation during induction head elevated; Participant to be ventilated starting 2 minutes after induction of general anesthesia via a face mask while in head elevated position. Participants will be crossed over to the supine position after the first measurement is obtained.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Average tidal volume	The primary outcome for this trial is the average tidal volume in 10 ventilations in each position, flat or head elevated.	During induction.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Predictors for difficult mask ventilation like BMI	Secondary outcome will be: the incidence and correlation of other predictors for difficult mask ventilation like BMI.	During induction
Predictors for difficult mask ventilation like presence of beard	Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like, presence of a beard.	During induction
Predictors for difficult mask ventilation like Mallampati classification III or IV	Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like Mallampati classification III or IV.	During induction
Predictors for difficult mask ventilation like age of 57 yo or older.	Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like, age of 57 yo or older.	During induction
Predictors for difficult mask ventilation like severely limited mandibular protrusion	Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like severely limited mandibular protrusion.	During induction
Predictors for difficult mask ventilation like history of snoring.	Secondary outcomes will be: the incidence and correlation of other predictors for difficult mask ventilation like history of snoring.	During induction
Oropharyngeal airway	Incidence of use of an oropharyngeal airway during the protocol.	During induction
Insufficient mask ventilation	Incidence of insufficient mask ventilation (defined as tidal volume (Vt) < 4 ml/kg IBW), or failed facemask ventilation defined as absence of End-tidal carbon dioxide(EtCO2) after 3 consecutive ventilations.	During induction.

Collaborators and Investigators

• Sponsor: Mount Sinai Hospital, Canada
• Investigators: Principal Investigator: Fabricio Zasso, MD, Mount Sinai Hospital

Study record dates

Study Major Dates

• Study Start (Estimated): March 25, 2024
• Primary Completion (Estimated): March 1, 2025
• Study Completion (Estimated): March 1, 2025

Study Registration Dates

• First Submitted: February 26, 2024
• First Submitted That Met QC Criteria: March 8, 2024
• First Posted (Actual): March 12, 2024

Study Record Updates

• Last Update Posted (Actual): March 20, 2024
• Last Update Submitted That Met QC Criteria: March 19, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Overnutrition; Nutrition Disorders; Overweight; Body Weight; Obesity
• Other Study ID Numbers: 23-0150-A

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No