Mastering Entonox: Drug Monograph

/ Delta Emergency Support Training/

Introduction:

Entonox, colloquially known as "laughing gas" is a valuable tool in the first responder's arsenal, offering rapid analgesic.

In guide, we'll delve into both contraindications and cautions associated with Entonox, using the acronyms DIVINE and SADMC.

How Entonox Works:

When inhaled, Entonox takes approximately 3 to 5 minutes to initiate pain relief, reaching its maximum effect within 5 to 10 minutes. A notable feature of Entonox is its rapid excretion from the body via the lungs upon cessation of inhalation, leading to a prompt reversal of the analgesic effect.

Key Benefits of Entonox:

  1. Rapid Analgesic Effect:

    • Entonox provides swift pain relief, making it an invaluable tool in emergency situations where quick intervention is paramount.

  2. Reversible Analgesic Effect:

    • The rapid reversal of the analgesic effect ensures that symptoms are not masked, allowing healthcare providers to assess patients accurately.

  3. Cardiac and Respiratory Safety:

    • When used properly, Entonox demonstrates no adverse effects on the cardiovascular or respiratory systems, enhancing its safety profile in diverse medical and trauma conditions.

  4. Self-Administration Capability:

    • Patients can self-administer Entonox, offering a sense of control over their pain management, particularly in situations where immediate assistance may be limited.

  5. Oxygen Enrichment:

    • With a 50% oxygen concentration, Entonox proves valuable in various medical and trauma scenarios where supplemental oxygen is beneficial, ensuring optimal oxygenation for patients.

Contraindications Acronym

  1. Decompression Sickness (D):

    • Do not give Entonox to anyone who has recently dived as the nitrous oxide is highly soluble and will increase the inert gas load, making the symptoms of DCI (Decompression Illness) much worse.

  2. Inability to Comply (I):

    • Patient cooperation is vital; those unable to hold the bite stick and inhale or someone who is in and out of consciousness are not suitable for Entonox

  3. Ventable Space (V):

    • Proper ventilation is key to prevent gas concentration buildup, ensuring safety in various environments.

  4. Inhalation Injury (I):

    • Burns to the mouth or throat, or recent exposure to fire and irrigation, warrant avoiding Entonox to prevent respiratory complications.

  5. Nitroglycerin (N):

    • Caution is needed with recent nitroglycerin use, as combining it with Entonox may lead to fainting.

  6. Embolism/Pneumothorax (E):

    • Entonox should be avoided with suspected pneumothorax or head injury, given its potential impact on pressure in the body.

Cautions (SADMC):

  1. Shock (S):

    • Monitor for shock, as Entonox may not work optimally in such cases. It is important to give high flow O2 to a patient with suspected shock.

  2. Abdominal Distention (A):

    • Similar to concerns with intercranial pressure and pneumothorax, avoid pressurized gas in patients with distended abdomens.

  3. Depressant (D):

    • Exercise caution when combining Entonox with other depressants like alcohol, ketamine, marijuana, benzodiazepines, or opioids. Synergistic effects can lead to increased depression.

  4. Maxillofacial Injury (M):

    • Patients with jaw injuries may struggle with the bite stick used in Entonox delivery. Adaptations may be needed for proper administration.

  5. COPD (C):

    • For patients with COPD that may have alveolar bullae (air pockets or blebs) as nitrous oxide may cause bullae rupture since nitrous oxide enters that closed space more quickly than nitrogen can escape.

Scope of Practice Awareness:

Being attuned to regional scope of practice guidelines is essential for first responders. Variations exist among provinces and private emergency response agencies, emphasizing the need for ongoing education and communication within your team. Stay informed to ensure Entonox is administered safely and effectively, adhering to your specific guidelines.

Practical Application in Training:

As part of our commitment to excellence, our Advanced First Aid courses include practical training in Entonox use. This hands-on experience allows first responders to familiarize themselves with the administration of Entonox in a controlled environment, ensuring confidence and competence in the field.

Conclusion:

By understanding both contraindications and cautions and staying abreast of regional scope of practice guidelines, first responders can navigate the complexities of Entonox administration with precision.