Introduction
Entonox composed of nitrous oxide and oxygen. It is widely use in the pre-hospital setting in countries overbroad and is yet to be introduced on Namibian ambulance services. This review focuses on the importance of Entonox and the author’s view on it. History and Appearance
Entonox comprises of 50% oxygen and 50% Nitrous oxide. Nitrous oxide dates back to 1799 and was found by a chemist in Yorkshire, it was inhaled by a scientist Humphry Davy and observed that it relieved him from pain, (Pediani, 2003). (Coll, 2011) on the other hand says that that it was found in 1776 by Joseph Priestley. Ever since it became popular in pain relief and was later used on the ambulance. It is commonly known as happy gas or laughing gas.
On the ambulance nitrous oxide comes in a blue cylinder with a white top. A hose is connected to the regulator on the cylinder and at the end of the hose is the facemask. Like the oxygen cylinder Entonox is highly pressurised
It is insoluble in the blood and after inhalation moves through the circulatory system to the central nervous system where it takes about 1-2 minutes to build up in reasonable concentrations, (Weddell, n.d.). In the brain Entonox acts on the endogenous opioid system specifically on morphine rich areas, (O’ Sullivan; Benger, 2003). The opioid system is located in the brain and is responsible for pain relief of the body, (Holden, Jeong, Forrest, 2005). It is also found in depression of the central nervous system which results in pain relief. It is easily removed from the body via the lungs while small amounts are removed through the skin. The term laughing gas comes from the side effect it causes in some patients. Not only does it relief pain it also causes the patient to feel happy, and for this reason this gas can be very addictive. The most common side effects are nausea and dizziness. By this time the emergency care provider should remove the mask and administer