Nitrous Oxide

Nitrous Oxide

Inhaled Analgesic

March 3, 2023

Dear Colleagues,

Welcome to another Pharmacy Phriday CE offering. In this installment, we will review the use of a pain medication rarely available to the EMS provider. Nitronox is a pain medication not as common to EMS as it once was but remains in the Special Use Medications section of your protocol as some agencies still do carry the medication and use it.

Nitronox, or laughing gas as it is sometimes referred to, is a gas combined as a 50/50 mixture of Nitrous Oxide and Oxygen that acts as an analgesic and anesthetic agent. Because it is inhaled through a mask, it has a rapid route to the bloodstream through the lungs. It works quickly to depress the central nervous system, resulting in sedation and analgesia. It can be used in many situations where the pain is a complaint of the patient. Under UH protocols Nitronox is approved for musculoskeletal trauma, fractures, burns, and kidney stones.

Nitronox is a medication that is self-administered by the patient. Because the mask must be held by the patient, the mask simply falls away from the face when the level of consciousness begins to drop. Once the patient stops inhaling the gas through the mask, the effects quickly dissipate, usually within 2-5 minutes.

There are several contraindications to the use of Nitronox that include:

NItronox can be used by the AEMT and Paramedic level provider where approved by the medical director. Dosing is self-regulated. The patient should be instructed to hold the mask firmly to their face and inhale deeply, continuing use until they experience relief from their pain. The provider should not hold the facemask in place for the patient.

Use of the Nitronox units should be limited to areas that are well-ventilated. Proper ventilation should include a fresh air ventilation system, a nitrous oxide scavenging system, or both. Because nitrous oxide is not heavily metabolized during inhalation, it may build up in the treatment area. Personnel may be affected by the exhaled nitrous oxide and experience some of the same effects as the patient undergoing treatment. And be aware that some studies have shown that even with ventilation, concentrations of the gas can still exceed recommended levels for staff exposure.

Occupational safety for the female provider regarding potential reproductive hazards also is a point of discussion and has been scrutinized. Providers should discuss these and other concerns with their local medical directors for further guidance.

Make safety a priority in all you do!


The UH EMS-I Team

University Hospitals