Get to Know Your Medical Kit – Oxygen Delivery Systems

“The most remarkable thing about breathing is just how unremarkable it is!”

When a guest or crew member has breathing difficulties, the airway and lungs can become noisy. It will require a lot of effort from the chest muscles to help get air and oxygen into the body. The breathing rate (10-20 breaths per minute) can become too fast or slow, and oxygen levels may be low (below 94%), or normal (above 94%). A common position someone will adopt when struggling to breathe is a tripod; hands leant on knees to open the space around the lungs.

The cause of breathing difficulties can come from a range of issues such as dive problems, asthma, anaphylaxis, sepsis, or a bleed or damage to the lungs. Whatever the cause, if a person is not taking approximately 10-20 breaths per minute (respiratory rate), and/or has an oxygen level below 94%, or are just looking very unwell (pale, clammy and blue around the edges), you need to act – and quickly!

Within minutes of a low oxygen state, the tissues of the vital organs will begin to malfunction and die. This could eventually lead to a seizure, coma, and the heart stopping. An oxygen kit should be transported as a priority to any medical incident, alongside the defibrillator and grab bag. The contents of the kit should be familiar to all crew from their annual pre-season medical training and monthly drills. It should also be regularly checked to ensure functionality.


Medical-grade oxygen should be used in a medical incident to provide a high concentration of purified oxygen. The cylinder will offer 20-30 minutes on a medium/high flow setting and requires a 3-year refill and 5-year hydrostatic pressure test or replacement. This is not available in all ports, so plan ahead. The pin-index regulator should be mounted on the cylinder to protect the rubber bodox seal. All components should be carefully secured in the strapping system within a water-resistant bag, or waterproof if on tenders.

A good safety check method is to slowly open the cylinder valve to check for audible leaks and the correct pressure volume on the dial. Then close the valve and drain the system by opening the flow valve or demand valve, whilst always following standard oxygen safety protocols.


BVM Oxygen mask

A slightly spacey-looking device that you regularly see on medical TV shows. For use when a casualty is not breathing sufficiently (under 8 breaths per minute), or when someone stops breathing completely. Start with 30 compressions followed by 2 breaths with the BVM. Use a c-grip to hold the mask and lift the chin with the same hand. Connect oxygen using the universal tubing from a face mask and start on high flow (15-20 LPM), gradually decreasing based on the pulse oximeter Sp02 reading. Squeeze the top of the chamber to deliver the breaths and aim to compress to the volume of a can of coke.


Non Rebreather Mask

This is the go-to for oxygen delivery to a breathing casualty post-trauma, following smoke inhalation, or with severe breathing difficulties, or severe pain. Start with high-flow oxygen (15-20 LPM), weaning down every few minutes to aim for a 94% oxygen level on the pulse oximeter. It is essential to monitor a casualty on oxygen as the masks pose a suffocation risk without oxygen flow.


Nasal Cannula

You may have a crew member or guest approach you who feels unwell with no obvious injury. For example, complaining of central chest pain during a heart attack, the oxygen level should be checked and a nasal cannula placed in the tip of the nose and looped behind the ears. Commence with a low flow of oxygen (4-6 LPM), gradually increasing as required to aim for that all-important 94% Sp02 (oxygen level). A good tool for anyone who won’t tolerate a mask well, e.g. a child who finds the mask too scary & overwhelming.


Demand Valve

This is a useful device that can deliver high-percentage, high-pressure oxygen via a mask. This can be done by either pressing a button until the chest rises in CPR breaths, or by placing over the mouth for breath activation in a conscious casualty. Highly recommended for dive incidents to remove nitrogen from the system. This device also conserves oxygen supplies over a longer period.


CPR Mask

A simple device to quickly provide CPR breaths while the bag valve mask or demand valve is set up. Remember to tilt the chin up to open the airway during use.


This can be utilised for unconscious casualties to stop the tongue rolling back and blocking the airway.

Choose a size by finding the one that best fits between the corner of the patient’s ear and the corner of the mouth.

Insert upside down (in a u-shape position) and twist over the tongue (ending in an n-shape position).

A guedel provides no protection from vomit. If necessary, turn the casualty on the side, remove the guedel and clear the airway, then replace with a clean guedel. Should you be unable to access the mouth -if there is jaw damage from a fracture- an alternative is a nasopharyngeal. This is a tube designed to insert into the nasal passageway to secure an open airway from the back of the throat.

Oxygen administration should always be conducted under Doctors’ or professional medical personnel’s guidance.

Check out your oxygen kits on board and get in touch if you require any advice or guidance.


Written by Sarah Graceson




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