What is Nitrogen Narcosis In Diving?
Nitrogen narcosis is a change in your level of awareness, muscle function, and behavior that happens when you breathe in a certain type of compressed gas. This condition is also called “depth intoxication”, “narks”, or “rapture of the deep”. It usually happens when scuba divers breathe nitrogen from their tanks that contain compressed air, which can cause problems.
Other types of gases that can lead to similar issues include neon, argon, krypton, and xenon. Interestingly, xenon can even have an anesthetic effect, which means it can cause loss of sensation, even at sea level. Surprisingly, helium doesn’t lead to this condition and is used in deep diving as part of a mix with oxygen, known as “heliox”.
What Causes Nitrogen Narcosis In Diving?
Narcosis is a state that can affect people while diving at deep levels underwater. It’s also known as nitrogen narcosis, inert gas narcosis, raptures of the deep, or the Martini effect. It is a temporary change in awareness that happens due to diving deeply.
When certain gases are under high pressure deep underwater, they can cause an effect similar to anesthesia, altering the diver’s mental state. This effect is reversible, meaning it goes away once the pressure returns to normal.
Risk Factors and Frequency for Nitrogen Narcosis In Diving
Reporting on diving-related injuries is not always consistent due to differences in how information is recorded. However, the Divers’ Alert Network (DAN), a service providing medical information and referrals for diving-related injuries, says that less than 1% of divers suffer from decompression sickness (DCS).
Signs and Symptoms of Nitrogen Narcosis In Diving
Nitrogen narcosis is a condition that can affect divers. Its effects can change significantly from person to person. While some divers might only experience symptoms at a depth of 60 to 70 meters, others might start to feel the effects at a depth of 30 meters. The symptoms don’t usually get worse over time if the depth is maintained, but they do get worse and new symptoms can come up if the diver descends deeper.
Typically, nitrogen narcosis first impairs a diver’s cognitive abilities, such as judgment, reasoning, short-term memory, and concentration. It might also make the diver feel euphoric or stimulated, similar to how they might feel with mild alcohol intoxication. If the diver continues to move deeper, the increased pressure might affect their manual dexterity and further deteriorate their mental faculties. This could include becoming fixated on an idea, experiencing hallucinations, and even losing consciousness or going into a coma. In severe cases, the impaired judgment resulting from nitrogen narcosis could cause an accident and even death during the dive.
There are factors which might increase the risk of experiencing nitrogen narcosis when diving and breathing compressed air. These include consumption of alcohol before the dive, fatigue, anxiety, and hypothermia. The levels of carbon dioxide in the blood could also make nitrogen narcosis worse, but not in a synergistic way. Instead, it’s more of an additive effect.
- Impaired-thinking abilities
- Euphoric or stimulated feeling
- Loss of manual dexterity
- Idea fixation
- Hallucinations
- Stupor or coma
- Increased risk factors: alcohol, fatigue, anxiety, hypothermia
- Additive effect of carbon dioxide in the blood
Testing for Nitrogen Narcosis In Diving
Scientists have been studying the impacts of nitrogen narcosis, which is a condition that can occur under high pressure underwater and can make a diver feel dizzy or confused. These studies have examined how nitrogen narcosis affects thinking, behavior, and changes within the brain. One investigation concerning simple math and reaction time showed that as pressure increased and divers breathed compressed air, they had more difficulty completing the tasks.
Another study aimed to compare the effects of nitrogen narcosis in a controlled laboratory setting and in open water. The scientists tested divers at different depths, both near the shore and in the open sea. They found that while signs of narcosis were seen in both 30-meter dives, the impairments were significantly greater in the ocean dive. Therefore, the researchers concluded that psychological stress, such as anxiety, could potentially enhance the effects of nitrogen narcosis when diving.
To better understand how nitrogen narcosis affects the brain, scientists have used a tool called an electroencephalogram (EEG) to measure brain activity. EEG studies have shown lower voltages in the divers’ basic brain rhythms, and the appearance of specific types of brainwaves, called theta waves, which are associated with drowsiness or relaxation. They’ve also looked at what’s known as “evoked potentials.” This is when the EEG readings respond to certain stimuli, such as visual images. A study using these visual evoked responses in US Navy divers found significant differences when the divers were breathing compressed air at depth. These results were not seen when the divers breathed a mixture of compressed helium and oxygen.
Treatment Options for Nitrogen Narcosis In Diving
Nitrogen narcosis, a condition that can affect divers, can be prevented in several ways. One of the simplest methods is to limit how deep you go when you dive. Generally, it’s recommended that divers using compressed air shouldn’t go deeper than 30 to 50 meters. If you need to dive deeper than this, it’s suggested to use a different type of gas instead of air to avoid getting nitrogen narcosis.
For dives deeper than 50 meters, divers often use other gases like helium or a mix of helium and nitrogen instead of oxygen. This is because helium doesn’t have the same numbing or intoxicating effect on divers as nitrogen can when they’re diving deep and breathing in compressed gases. But it’s worth noting that helium can make the process of decompressing after diving more intensive than nitrogen does.
The treatment of nitrogen narcosis involves being able to recognize the signs of the condition early. This can be done either by the diver themselves or by their diving partner while they’re still under the water. This condition clears up completely within a few minutes when the diver starts to ascend. However, if the symptoms of nitrogen narcosis continue, it is recommended to stop the dive and return to the surface.
What else can Nitrogen Narcosis In Diving be?
There are several potential diving-related complications, including:
- Arterial gas embolism – a gas bubble trapped in a blood vessel
- Caustic cocktail from rebreathing circuit – inhaling a dangerous mix of gases
- Contaminated gas mixture – using oxygen-containing gas that’s impure or toxic
- Decompression sickness – sickness from surfacing too quickly and causing nitrogen bubbles to form in the blood
- Face squeeze – pressure-related facial discomfort
- Hypothermia – dangerously low body temperature
- Nitrogen narcosis – impaired consciousness due to high nitrogen levels in the body
- Oxygen toxicity – too much oxygen in the body
- Pulmonary barotrauma (pulmonary overpressurization syndrome) – lung damage due to changes in air pressure
- Sinus barotrauma – damage to the sinuses due to changes in air pressure
What to expect with Nitrogen Narcosis In Diving
Simply put, inert gas narcosis, a condition that can occur during deep dives, gets better once you ascend or come back up. This condition doesn’t cause any long-term problems or make you more (or less) likely to get it again after repeated dives. Nonetheless, every time you go back under high pressure, like when you’re diving deep into the water, you could get inert gas narcosis again.
The tricky part is, you can’t predict how severe it will be, and it can even be dangerous while diving. This is because it can affect your thinking processes and decision-making skills while navigating in the underwater environment, which could lead to fatal accidents.
