Nitrous oxide
Also known as: Entonox, Laughing gas
Nitrous oxide (often called 'laughing gas') is a safe and commonly used gas that veterinarians use alongside oxygen and other anesthetics to keep your pet asleep and pain-free during surgery. It helps the main anesthetic work faster and allows the veterinarian to use lower doses of other drugs. It leaves the body very quickly once the procedure is over, allowing for a smooth recovery.
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
What it is used for
- Adjunct for induction and maintenance of anaesthesia
- Adjunct for induction and maintenance of anaesthesia
How it is given
Possible side effects
- Diffusion hypoxia (if oxygen is not supplemented upon discontinuation)
- Megaloblastic changes in bone marrow (with exposure lasting a few hours)
- Agranulocytosis (with prolonged exposure of a few days)
Cautions & contraindications
- Patients with air-filled spaces within the body (e.g., pneumothorax, gastric dilatation/GDV, intestinal obstruction)
- Marked respiratory compromise (due to hypoxia risks)
- Raised intracranial pressure (due to associated increases in cerebral blood flow)
- **Human Safety & Scavenging:** Prolonged exposure can have serious adverse effects on human health. Active scavenging is essential. > **Important:** N2O is **not** absorbed by activated charcoal in passive scavenging systems. **Hypoxia Risk:** A minimum oxygen concentration of 30% is required during anaesthesia. The inspired concentration of oxygen may fall to critically low levels when N2O is used in rebreathing circuits during low flow rates. Do not use in such systems unless the inspired oxygen concentration can be measured on a breath-by-breath basis. **Diffusion Hypoxia:** Always supplement with 100% oxygen for 5-10 minutes after turning off N2O.
Frequently asked questions
What is Nitrous oxide used for in pets?
Nitrous oxide (often called 'laughing gas') is a safe and commonly used gas that veterinarians use alongside oxygen and other anesthetics to keep your pet asleep and pain-free during surgery. It helps the main anesthetic work faster and allows the veterinarian to use lower doses of other drugs. It leaves the body very quickly once the procedure is over, allowing for a smooth recovery.
Is Nitrous oxide safe for my pet?
Dosage must be set by your veterinarian for your specific pet. Never give human medication or another pet’s prescription without veterinary guidance.
This article is for general education and is not a substitute for professional veterinary advice. If your pet is unwell, please consult a veterinarian.
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