A Novel Method of Preoxygenation Using a Bain Circuit

National Health Service, United Kingdom

Status and phase: Unknown; Phase 4

Conditions: Healthy Volunteers

Treatments: Drug: Oxygen

Study type: Interventional

Funder types: Other

Identifiers

NCT00958178

08/S071038

Details and patient eligibility

About

The purpose of this study is to determine whether rebreathing for a short time (a bit like breathing into a paper bag) will stimulate faster breathing and thus make the giving of Oxygen more effective.

The hypothesis is that the investigators method (rebreathing) will be faster than the current method of administering Oxygen.

Full description

It is standard practice for patients to breathe oxygen before receiving a general anaesthetic. This is called preoxygenation. It is done by using a mask which fits snugly onto the face. But for how long should patients breathe oxygen? Is taking deep breaths a good idea? What is the best oxygen flow rate? These questions are important because preoxygenation is one of the things which makes anaesthesia safe, so finding the best way of doing it might help save lives. Previous research has attempted to identify the best way to give oxygen before anaesthesia. It seems that breathing pure oxygen for three minutes is enough, or if you are in an urgent situation, then taking deep breaths of pure oxygen for a minute will do. However, there is another possible way of doing it which has not yet been looked at.

Asking someone to breathe back in the air they have just exhaled seems, on the face of it, to be pointless at best. But doing just that for a very short time will make the person breathe harder. Then when you give them pure oxygen, they will breathe it in really deeply and this might make the preoxygenation quicker. That's the theory. To test it we plan to ask 40 healthy people to do the standard preoxygenation, then try our new way. We won't be giving anaesthetic, just the oxygen.

The hypothesis is that our new method will be quicker than the existing one.

Enrollment: 40 estimated patients

Sex: Male

Ages: 18 to 40 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• BMI 18-27
• Non-smoker
• No chronic cardiorespiratory or neuromuscular illness
• No intercurrent illness

Exclusion criteria

• Unable/unwilling to consent

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Crossover Assignment

Masking: Double Blind

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40 participants in 2 patient groups

Rebreathing method of preoxygenation

Experimental group

Description:

Subjects will breathe Oxygen through a close fitting mask, but the flow will be low so that they rebreathe some of their expired air. After 30 seconds, the flow will be turned up so that they will breathe 100% Oxygen.

Treatment:

Drug: Oxygen

T method of preoxygenation

Active Comparator group

Description:

Tidal breathing of 100% oxygen through a well fitting facemask, for 4 minutes.

Treatment:

Drug: Oxygen