Nitrous oxide
Overview
- For minimal sedation or anxiolysis
- It may be used as an adjunct with local anesthetics for more painful procedures
Indications
- Older than 4 years and/or weighing greater than 15 kg
- ASA Class 1 or 2
- Sole Nitrous Oxide use examples include:
- Peripheral or Central IV placement
- Urinary catheter insertion
- Intramuscular injections
- Joint aspiration or injection
- Lumbar puncture
- Laceration repair
- Abscess incision and drainage
- Nail removal
- Wound packing or dressing change
- Foreign body removal
- Nitrous Oxide + opioid or benzodiazepine examples include (smaller dosages should be used initially and titrated PRN)
- Lumbar puncture
- Laceration repair
- Abscess incision and drainage
- Foreign body removal
- Simple or minimally displaced fracture reduction
Contraindications
Nitrous accumulates in potential spaces and is potentially problematic when there are recent lung or ocular surgery.
- Caution should be used when combined with benzodiazepines or other sedatives
- Age less than 4 years and/or weight less than 15 kg
- ASA Class 3 or above
- Closed head injury, recent craniotomy, altered level of consciousness or suspicion of elevated intracranial pressure
- Penetrating globe injury or recent eye surgery
- Complex upper respiratory infection (obstructive sinusitis, bullous otitis media)
- Maxillofacial injuries
- Acute asthma, bullous emphysema or pneumonia
- Pneumothorax or chest trauma
- Pulmonary hypertension
- Congenital heart disease
- Bowel obstruction or ileus
- Recent SCUBA diving, barotrauma or decompression illness
- Pregnancy
Equipment Needed
Procedure
- Pre-sedation establishment of an IV is not required
- General monitoring procedures shall be followed
- Nitrous oxide administration should be limited to 30 minutes
- Administer 100% oxygen for 2-5 minutes after discontinuing nitrous oxide or if nitrous oxide / oxygen administration is interrupted for > 30 seconds
Complications
- Asphyxia, if oxygen is not given with the gas
- Headache
- Dizziness
- Confusion
- Syncope
- Seizures
- Chronic toxicity results from B12 inactivation
- Megaloblastic anemia
- Thrombocytopenia
- Peripheral neuropathy