Nitrous Oxide

Brand names  Reversal agents Warnings 
Description  Side effects and risks Alternative medications 
Dosing  Common issues Contraindications 


Brand Names

Kalinox
Entonox

Description

Nitrous oxide is a colorless, slightly sweet-smelling gas that is inhaled to produce analgesic and anxiolytic effects. When used for endoscopic sedation it may be co-administered with oxygen and can be self-administered by the patient through a mask or mouthpiece. Nitrous oxide quickly passes the blood-brain barrier resulting in a rapid onset of action. Additionally, it is cleared quickly from the body leading to a shorter recovery time than with intravenous sedation. There is a very low incidence of adverse reactions associated with nitrous oxide.

Dosing

 Nitrous Oxide Dosing for Endoscopic Sedation

Adult  

  • Initial dose:  Titrate to effect
  • Onset of action:  2-3 minutes
  • Peak effect:  Dose dependent
  • Duration of effect:  15-30 minutes

Pediatric

  • Same as adult

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Reversal Agents

  • None

Side Effects and Risks

  • The primary risk of nitrous oxide is hypoxia. This is ameliorated by co-administering with 30% to 50% oxygen.
  • Hypertension, arrhythmias, nausea, vomiting, and headache have been reported with nitrous oxide.

Common Issues

  • Headache has been cited in several studies as a frequent side effect of nitrous oxide sedation.
  • Respiratory depression can occur with nitrous oxide. 

Warnings

Health care workers exposed to nitrous oxide can experience decreases in mental performance, audiovisual ability, and manual dexterity. Studies have reported that long-term exposure may result in adverse health effects including reduced fertility, spontaneous abortion, and neurological, renal, and liver disease. Engineering controls, work practices, and respirators (when necessary) should be used to minimize the exposure of workers to nitrous oxide.

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Alternative Medications

  • None

Contraindications

  • Some chronic obstructive pulmonary diseases
  • Severe emotional disturbances or drug-related dependencies
  • First trimester of pregnancy
  • Treatment with bleomycin sulfate
Sources

Cohen LB, DeLegge MH, Aisenberg J, Brill JV, Inadomi JM, et al. AGA Institute review of endoscopic sedation. Gastroenterology. 2007 Aug;133(2):675-701.

Controlling Exposures to Nitrous Oxide During Anesthetic Administration. NIOSH ALERT: 1994. DHHS (NIOSH) Publication No. 94-100. http://www.cdc.gov/niosh/noxidalr.html  Accessed April 28, 2008.

 

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Last Updated October 9, 2008