Nitrous Oxide in the ED
Alexis Lapietra and Anand Swaminathan
- Nitrous oxide (NO) is a colorless, tasteless gas inhaled in combination with oxygen.
- It is administered either through a full face mask (commonly seen in the ED) or a nasal hood (more common in the outpatient setting).
- It is rapidly absorbed in the lungs and rapidly cleared (about 30-60 seconds).
- No allergies have been reported.
- It has proven to be extremely safe in adults and kids.
- It provides anxiolysis, amnesia and analgesia.
- When given as a sole agent, it is not considered procedural sedation. Often, it is used in combination with other medications (such as midazolam or fentanyl). In this case, it is considered a full procedural sedation.
- Procedures amenable to the use of nitrous oxide.
- Most common ED procedures such as laceration repair, abscess drainage, fracture reduction, lumbar puncture, cardioversion, central line placement, fecal disimpaction, and wound/burn care.
- Can be safely used in 3rd trimester pregnancy.
- Advantages of nitrous oxide over traditional PSA agents.
- Extensive monitoring (cardiac or EtCO2) is not required.
- No intravenous line is needed.
- It does not cause apnea.
- Nitrous oxide is a hemodynamically stable agent.
- Places where nitrous oxide is contraindicated.
- Nitrous oxide can collect in air filled spaces causing barotrauma.
- Avoid small bowel obstruction, pneumothorax, air embolism, pneumocephalus, recent eye surgery, COPD patients with bullae/blebs.
- Contraindicated in first and second trimester pregnancy.
- Nitrous oxide use
- Typical setup is with a portable unit that houses the nitrous oxide tanks and connects to wall oxygen.
- A 70/30 nitrous to oxygen mixture is shown to be the most effective.
- Dr. Lapietra recommends monitoring the patient with pulse oximetry. Although it is technically not necessary, this is a compromise with hospital administration.
- Portable unit has a scavenger to ensure staff and other patients are not being exposed to nitrous oxide.
- Can be administered by face mask or nasal hood.
- Of note, administration of nitrous oxide is not billable as procedural sedation. This has likely limited its availability in many hospitals.
Analgesic Effect of Nitrous Oxide/Oxygen Mixture for Traumatic Pain in the Emergency Department: A Randomized, Double-Blind Study
The Benefits of Introducing the Use of Nitrous Oxide in the Pediatric Emergency Department for Painful Procedures
A randomized controlled study in reducing procedural pain and anxiety using high concentration nitrous oxide
Resolution of Acute Priapism in Two Children With Sickle Cell Disease Who Received Nitrous Oxide
Ketamine procedural analgosedation before and after introducing nitrous oxide 70% in a paediatric emergency department
Efficacy, pain, and overall patient satisfaction with pediatric upper arm fracture reduction in the emergency department
The use of inhaled nitrous oxide for analgesia in adult ED patients: a pilot study
Laryngospasm With Apparent Aspiration During Sedation With Nitrous Oxide
Self-administered procedural analgesia using nitrous oxide/oxygen (50:50) in the pediatric surgery emergency room: effectiveness and limitations
Nitrous oxide for early analgesia in the emergency setting: a randomized, double-blind multicenter prehospital trial
Nitrous Oxide, From the Operating Room to the Emergency Department
The effect of nitrous oxide in comparison to oxygen combined with fentanyl on the hospitalization time and pain reduction in renal colic patients at emergency department
Oral Ondansetron to Reduce Vomiting in Children Receiving Intranasal Fentanyl and Inhaled Nitrous Oxide for Procedural Sedation and Analgesia: A Randomized Controlled Trial
Protocol for a double blind, randomised placebo-controlled trial using ondansetron to reduce vomiting in children receiving intranasal fentanyl and inhaled nitrous oxide for procedural sedation in the emergency department (the FON trial)
A fixed nitrous oxide/oxygen mixture as an analgesic for trauma patients in emergency department: study protocol for a randomized, controlled trial
Closed reduction of paediatric forearm fractures: nitrous oxide versus general anaesthetic
Retrospective Comparison of Intranasal Fentanyl and Inhaled Nitrous Oxide to Intravenous Ketamine and Midazolam for Painful Orthopedic Procedures in a Pediatric Emergency Department
Intranasal fentanyl and inhaled nitrous oxide for fracture reduction: The FAN observational study
Combined nitrous oxide 70% with intranasal fentanyl for procedural analgosedation in children: a prospective, randomised, double-blind, placebo-controlled trial
A randomized comparison of nitrous oxide versus intravenous ketamine for laceration repair in children