When “Laughing Gas” Stops Being Funny

Ok.. that title is a little cynical but it was enough to get your attention, right?

In a previous newsletter, we explored the increasing prevalence of recreational nitrous oxide (“NOS”, “laughing gas”) use among young people and highlighted the growing number of neurological complications presenting to NHS services.

This week, I wanted to revisit the subject through a particularly concerning urgent care presentation that underscores an emerging challenge for frontline clinicians: acute oral and airway injury caused by direct exposure to pressurised nitrous oxide canisters.

Nitrous Oxide - The New Drug in Town

You see, I’m someone that really analyses and questions my surrounding and for a long time I noticed small metal canisters on the floor and wondered what they were.

This was a really interesting case. Not only was a potentially serious injury but it was also a difficult case to navigate as there is a lack of unified guidance on how manage nitrous oxide burns (as they are rare). Let’s get into the case itself:

A 17-year-old patient presented to urgent care with a significant sore throat, oral burning, and tongue pain two days after a nitrous oxide canister reportedly exploded in her mouth during recreational use.

She described:

• Severe pain in the mouth and throat
• A white lesion on the tongue
• Reduced sensation under the tongue
• Difficulty tolerating oral intake

Clinical examination demonstrated:

• Marked erythema of the soft palate
• A large white ulcer affecting the tip of the tongue, extending from the ventral surface dorsally
• Mild oedema within the floor of mouth
• Intact frenulum
• No immediate airway compromise

Whilst the ulcer looked quite bad, I wasn't too concerned as the management would be the same as any other ulcer. However it was the oedema within the floor of the mouth that concerned me. This swelling could progress and result in significant airway complications. I decided to call the maxillofacial team locally and the patient was transferred over for review.

The Clinical Challenge: Where Is the Guidance?

One of the most striking aspects of this case was the relative absence of unified guidance surrounding the management of these injuries.

While there is increasing awareness of the neurological sequelae of nitrous oxide misuse, particularly functional vitamin B12 deficiency and subacute combined degeneration, guidance regarding acute thermal or cryogenic oral injuries remains limited.

Currently:

• There is no dedicated NICE guideline specifically addressing oral thermal or cryogenic injury from recreational nitrous oxide exposure.
• Existing toxicology and emergency medicine guidance focuses primarily on:neurological toxicity,
• hypoxia,
• barotrauma,
• and asphyxiation.

The Royal College of Emergency Medicine (RCEM) nitrous oxide guidance does, however, acknowledge that recreational nitrous oxide use can cause:

• cold injuries to the lips or mucosa,
• barotrauma,
• pneumomediastinum,
• and airway-related complications.

Importantly, nitrous oxide released from pressurised canisters can reach temperatures of approximately −45°C to −50°C, producing cryogenic thermal injury to oral mucosa when inhaled directly from cartridges or cylinders. This is what we were dealing with in this case.

In practical terms, these injuries should be approached similarly to thermal burns of the oral cavity, with careful assessment of:

• airway stability,
• floor of mouth swelling,
• evolving oedema,
• swallowing difficulty,
• secondary infection risk,
• and tissue necrosis.

Why This Matters for NHS Clinicians

Nitrous oxide misuse is not rare.

According to UK national data:

• Nitrous oxide was previously the third most used recreational drug in England and Wales after cannabis and cocaine.
• Between 2017–2020, approximately 8.7–8.8% of 16–24-year-olds reported use.
• The Office for National Statistics estimated that around 796,000 individuals misused nitrous oxide in England and Wales between 2019–2020.

The rise in larger recreational canisters has also changed the injury profile clinicians may encounter. RCEM guidance notes anecdotal increases in presentations related to heavier use and larger cylinders.

As clinicians, we are increasingly likely to encounter patients with such burns. As for red flags, here are some of the most important to consider in the context of nitrous oxide:

• Progressive floor of mouth swelling
• Voice change
• Dysphagia or odynophagia
• Drooling
• Stridor
• Reduced tongue mobility
• Soft tissue crepitus
• Respiratory compromise

The presence of any of these should entail early involvement of OMFS/ENT.

In burns that do not require escalation such as this one, simple management could involvement

• soft diet/hydration advice,
• analgesia - difflam or steroids mouth wash
• safety net the patient for drooling, stridor, mouth swelling and other red flags listed above.

Key Learning Points

So let’s bring it all together with some key learning points:

• Recreational nitrous oxide use remains common among UK adolescents and young adults.
• Direct inhalation from canisters may cause severe cryogenic oral burns.
• Floor of mouth oedema should prompt consideration of evolving airway compromise.
• Current NICE guidance specific to oral nitrous oxide injuries is lacking.
• Early senior review and low threshold for OMFS/ENT involvement are advisable where swelling is present.

Until next time…

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Originally published on Substack.