ReviewLaughing gas abuse is no joke. An overview of the implications for psychiatric practice
Introduction
Nitrous oxide (N2O), commonly known as laughing gas, is used in medicine as a volatile anesthetic. In addition to its medical use, it has many applications in the food and car industries. In these contexts it is used as a propellant in whipped cream dispensers, as an engine accelerant and as an oxidizer in rocket engines. Whipped cream cans or gas cartridges make N2O available to a larger public and they can be purchased in most supermarkets under the name “whippits” for about 15 euro for 50 bulbs [1]. The cartridges may be opened by puncturing the end and capturing the escaping gas in a large container or in an inflatable object such as a balloon, thus making nitrous oxide ready for inhalation [2]. Cases are described where the patients discharge the “whippits” into a container and then directly inhale via a facial mask [3], [4].
After the first report of its kind in 1978, [5] attention for N2O abuse increased. An anonymous questionnaire of 1979 [6] in the USA revealed that up to 20% of medical and dental students had at one time inhaled nitrous oxide for recreational purposes. A questionnaire-based study of 2003 [7], [8] at the University of Auckland, New Zealand showed in more detail that 12% of the first-year students used the substance recreationally and 3% inhaled it at least monthly.
The purpose of this paper is to present an overview of the psychiatric effects of N2O inhalant use and raise clinical awareness by means of case reports in which the psychiatric symptoms are prominent. The implications for psychiatric practice in terms of the screening and assessment aimed at these substance-using populations will be documented and discussed.
Section snippets
Case report
A 24-year-old, Caucasian male with no psychiatric history was brought to the emergency department (University Hospital Gent, Belgium) by his parents because of his altered mental status and bizarre behavior. His confusing story about turning the world into a better place was colored with paranoia. The parents reported that the patient had never had similar thoughts or delusions in the past. He worked as a technician in a nuclear plant and ruled out occupational exposure to any toxic substance.
Method
We used the search engine PUBMED to find relevant papers on nitrous oxide and psychiatric symptoms by using the search words “nitrous oxide” and “psychiatric symptoms”. This yielded 23 results. In addition, the references cited in the papers found were symptomatically checked for relevance to this paper.
Discussion
Despite the fact that there are a number of case studies that report clinical findings of sensory and motor dysfunction, we will concentrate on the only cases found in the literature until now that describe psychiatric symptoms (e.g. psychosis and conversion disorder) as prominent.
Sethi et al. [3] describe the case of a 33-year-old, unemployed Indian–American male with no past psychiatric history, who was brought to the hospital because of his bizarre behavior and paranoid delusions. The
Conclusion
In this review we have pointed out the importance of including nitrous oxide in the drug history of substance-using patients who present themselves at the hospital with unexplained psychiatric abnormalities.
Screening for N2O use may help identify individuals who are at a higher risk for inhalant abuse and who may benefit from targeted treatment and prevention interventions. Screening can be done through the alcohol, smoking and substance involvement screening test (NIDA ASSIST), the Volatile
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