Harmful effects of nitrous oxide laughing gas

The Institute of Mental Health, Bach Mai Hospital has just sent a report assessing the impact of N2O gas on human health to the Department of Science and Training, Ministry of Health .

Nitrous oxide is also known as "laughing gas", coined by Humphry Davy, due to its euphoric effects when inhaled, a property that has led to its use as a recreational drug. It is on the World Health Organization's List of Essential Medicines.

Illustration photo.

Nitrous oxide ( Nitrogen Oxide) has the chemical formula N2O, is a chemical widely used in many fields such as industry, medicine and food industry.

However, in recent years, the use of Nitrous Oxide worldwide for recreational purposes has been increasing rapidly, especially in bars, discos and festivals.

In the UK, nitrous oxide is the most popular recreational drug, according to a 2016 report. In Vietnam, there have been repeated cases of poisoning due to the use of this product at medical facilities.

The report of the National Institute of Mental Health clearly shows that the use of nitrous oxide is believed to have serious consequences for human health. The situation of nitrous oxide abuse, especially among adolescents, requires special attention.

N2O is very fast acting and produces physiological effects (such as pain relief, euphoria and hallucinations) within seconds of inhalation. Concentrations peak after about 1 minute and disappear within a few minutes with no hangover effects and the user can return to normal activities shortly after inhalation.

Therefore, nitrous oxide is used as a recreational drug because of its ability to produce a short-term "high". Most recreational users are unaware of its toxicity to the brain and its potential for acute and chronic damage.

Nitrous oxide is one of the gases that cause global warming. According to statistics, nitrous oxide accounts for 6% of total greenhouse gas emissions in the United States, arising from human activities such as agriculture, fuel burning, wastewater management and industrial processes.

In the fuel industry, Nitrous Oxide is used as an oxidizer for rocket propellants and in racing to increase engine power output.

In the food industry, N2O is used as a mixing and foaming agent (R942) in the production of whipped cream. Nitrous oxide is also present in the atmosphere as part of the nitrogen cycle. These molecules remain in the atmosphere for an average of 121 years before being removed by bacteria in the soil, ultraviolet radiation from the sun, or destroyed through chemical reactions. 5

For recreational use, nitrous oxide is often sold in prefilled balloons or small pressurized metal canisters designed for the food industry.

Industrial production of Nitrous Oxide involves heating ammonium nitrate to 2500C followed by removal of impurities, such as NH3, N2, N2, NO2, HNO3 using specialized equipment. Poisoning can occur if nitrous oxide is inhaled with the above impurity gases.

Nitrous oxide is usually stored in cylinders below its critical temperature, so that it exists as a vapor per volume of liquid nitrous oxide. These cylinders are filled to accommodate the increase in pressure as the vapor phase expands. Filling the cylinder and storing it above the critical temperature poses a risk of explosion. 2

Nitrous oxide has been used in dentistry and surgery as an anesthetic and pain reliever since 1844. Sneader, Drug Discovery. In the early days, the gas was delivered through simple inhalers consisting of a breathing bag made of rubber fabric.

Today, nitrous oxide is used in hospitals through relatively automated pain machines, anesthesia machines, and medical ventilators, which deliver a precisely metered flow of nitrous oxide mixed with oxygen in a 2:1 ratio.

Nitrous oxide is a weak general anesthetic and is therefore not usually used alone in general anesthesia but is used as a carrier gas (mixed with oxygen) for more potent general anesthetics such as sevoflurane or desflurane. The use of nitrous oxide in anesthesia may increase the risk of postoperative nausea and vomiting.

Dentists use a simple machine to store and dispense the mixture for the patient to inhale while awake, with a flow meter to ensure a relative analgesic gas mixture ratio of at least 30% oxygen at all times and a maximum upper limit of 70% nitrous oxide.

Nitrous Oxide inhalation is commonly used for pain relief in childbirth, trauma, oral surgery, and acute coronary syndrome. Its use during labor has been shown to be a safe and effective aid in women in labor.

In the UK and Canada, Entonox and Nitronox are commonly used by ambulance crews (including unregistered practitioners) as a highly effective and rapid-acting analgesic gas.

50% nitrous oxide may be considered for use by trained non-professional first aiders in pre-hospital settings, as the use of 50% nitrous oxide as an analgesic is relatively easy and safe.

N2O inactivates cobalamine (also known as vitamin B12) by oxidizing Cob(I)alamine to Cobalamin(III) and consequently causes functional vitamin B12 deficiency, especially in people with low blood B12 stores.

According to Gilman's research, N2O has analgesic effects through its effects on the opioid system. N2O activates opioid neurons in the brain, causing the release of endogenous opioids in the brainstem, inhibiting neurons that release gamma-aminobutyric acid (GABA), thereby activating noradrenergic pathways and ultimately relieving pain.

The effects of N2O are also mediated through α1-adrenergic and α2-adrenergic receptors in the spinal cord. In addition, N2O blockade of NMDA receptors increases inhibition on dopamine neurons by GABAergic cells, especially in the ventral tegmental area and nucleus accumbens, resulting in dopamine bursts.

Regarding consequences, studies on the region-dependent effects of N2O on the dopamine, noradrenaline, and NMDA receptor systems have explained the clinical manifestations of euphoria, psychotic symptoms (hallucinations), impulsive behavior disorders, and aggression.

According to Oussalah et al. 2019, exposure to N2O can lead to serious consequences. According to a 2016 global psychoactive substance use survey of more than 100,000 respondents from over 50 countries, 4% of infrequent N2O users reported symptoms of neurotoxicity, with approximately 3% of users reporting paresthesia.

The most common acute clinical symptoms include paresthesia (80%), gait instability (58%), and limb weakness (43%). Some less common acute clinical symptoms include hemiparesis, numbness of the limbs, and vestibular disorders.

In a global survey of psychoactive substance users, in addition to neurological symptoms, psychiatric symptoms may also appear acutely, such as delusions, hallucinations, and cognitive disorders.

Prolonged, continuous use of N2O has been associated with serious chronic consequences, such as peripheral neuropathy, myelopathy, and demyelinating diseases, collectively known as demyelinating polyneuropathy (GDP). These diseases manifest clinically through muscle weakness, vestibular disorders, and numbness, which can eventually lead to paralysis of the limbs.

Recent spinal cord magnetic resonance imaging studies show progressive degeneration of the spinal cord, specifically in the posterior and lateral columns of the spinal cord in N2O users.

A positive correlation was found between the level of N2O use and the degree of myelopathy and GDP, and most chronic N2O users (mean: 300 laughing gas canisters/day for 6 months) had signs of neuropathy due to Cobalamin deficiency.

Cobalamin (vitamin B12) supplementation causes significant neurological improvement or even recovery in most patients, however, some patients will have only partial recovery, with persistent neuropathies, such as paresthesias, limb weakness, and/or paralysis.

Furthermore, prolonged use of N2O also leads to the appearance of psychiatric symptoms (anxiety, depression, mania, psychosis, cognitive disorders and delirium).

Psychiatric symptoms may appear simultaneously with disorders due to neurological damage (paresthesia, numbness, gait disturbances, weakness, paralysis of limbs) or may appear independently without accompanying neurological disorders.

Common psychiatric manifestations: depression, hypomania, anxiety, psychotic disorders: paranoia, hallucinations (auditory hallucinations, visual hallucinations), behavioral disorders (appearance of impulsive, aggressive, violent behavior) or personality changes.

People who abuse N2O may also exhibit cognitive disturbances such as memory impairment, language disorders, perceptual disturbances, and delirium.

In conclusion, the report of the Institute of Mental Health stated that N2O has been discovered and produced, and is widely used in industry and medicine. However, recently, the abuse of N2O as a recreational substance has increased rapidly and is difficult to control.

The consequences of N2O when used improperly, beyond recommendations, are very serious, affecting many organs and systems in the body.

Common neurological lesions such as spinal cord injury, polyneuropathy due to loss of myelin sheath cause symptoms of paresthesia, unsteady gait, and weakness of the limbs.

Psychiatric disorders such as delusions, hallucinations, behavioral disorders, mania, depression, anxiety, cognitive disorders. Accompanied by risks of abuse, dependence and concomitant use of other psychoactive (addictive) substances.

Several case reports have also shown the risk of death from N2O when respiratory and cardiovascular damage was detected.

Source: https://baodautu.vn/tac-hai-cua-khi-cuoi-nitro-oxide---n2o-voi-suc-khoe-con-nguoi-d226276.html