You are here

Warning message

The subscription service is currently unavailable. Please try again later.

Diver Life: Understanding Decompression Illness And Decompression Sickness

Decompression sickeness is one of the most common health problems affecting divers. This is mostly caused due to hasty ascent, when the difference in pressure causes nitrogen and other dissolved gasses to form tiny bubbles that make their way into the blood stream and the body’s tissues.   

DCI (Decompression Illness) is an overall term used to describe both decompression sickness (DCS) as well as lung over expansion injuries (Arterial Gas Embolism and dysbaric injuries). DCI and DCS occur at varying levels and are quite common among divers. There are two distinct types of decompression sickenss:

Type I DCS: This type of decompression sickness causes painful bubbles to form in the skin. Sometimes it extends to the joints. It is respectively classified as cutaneous DCS and joint and limb pain DCS.

Type II DCS: This type of decompression sickness is marked by serious neurological DCS and pulmonary DCS symptoms.

Though holding one’s breath during ascents and not taking appropriate safety stops contribute to decompression illness, there are cases in which DCI has occurred in divers who have performed perfect ascents and followed all table recommendations to the letter.

Signs and Symptoms of DCS:

In decompression sickness, dissolved gases form bubbles, which travel through the bloodstream and make their way throughout the body. Some commonly affected body parts include the limb joints (elbow, knee, shoulders and ankles).  Also known as the bends, decomprssion illness manifests as neurological symptoms in approximately 10% of all cases and as skin injuries in about 15% of all known cases. It is possible to suffer from bubbles in various body parts, so if you’re affected you may have one or more of the following common signs and symptoms of DCS:

  • Bends: Localized pain in large joints of the body, which increase when moved. Flexing the joint to a certain angle can sometimes reduce the pain.

  • Skin Bends: This can be described as any of the following, including swollen skin with tiny raised areas, itchy skin around the shoulders, arms and chest, itchy skin in the face, ears, arms and neck or sensation of insects crawling all over the skin.

  • Neurological: This can be further classified into:

    • Inner Ear: DCS can affect the inner ear causing instability, severe vertigo and hearing problems.

    • Spinal: Severe pain followed by ascending weakness ultimately leading to paralysis. It can also cause tingling, stinging or burning sensations in the back.

    • Brain: Symptoms of decompression sickness that have affected the brain include memory loss, tunnel vision, blurry vision, headaches, fatigue, nausea, dizziness, and vertigo.

    • Chokes: The symptoms of chokes are a burning sensation in the chest, a feeling of breathlessness, and a burning sensation which increases when breathing. A dry cough is often present as well.

It is important to note that the symptoms of decompression illness often occur immediately after a dive, but in extremely rare cases they can occur during the dive itself. Symptoms often occur between one to six hours after the dive, so don’t ignore them even if it has been a while since you surfaced. Some activities are known to increase the chances of DCS ; for example, taking a very hot shower, sitting in a hot tub, or working out right after diving can exacerbate problems. This happens because the gases in your blood are in a liquid state until you’ve offgassed completely. When you enter a hot tub or take a hot shower, the heat from the water causes the gasses to precipitate and form bubbles instead of being expelled normally. Intense workouts increase body temperature, after which the gases form bubbles caused by body heat.

Prevention of DCS and DCI

Both DCI and DCS can be prevented if:

  • You dive using dive computers and strictly follow the data in it.
  • Recreational divers do not go beyond the depth they are used to or try diving further than what was planned.
  • Experienced and commercial divers do not dive more than 10 meters deeper than what their computer advises them to.
  • You ascend cautiously with the required time at each depth.
  • By performing safety stops as and when necessary.
  • You avoid deep, long dives.
  • You avoid strenuous exercise after dives. The symptoms do not occur immediately, so you may be tempted to exercise. Take it easy instead.
  • You avoid air travel immediately after a dive.  

Treating Decompression Sickness

The first treatment for decompression illness is administering 100% oxygen until hyperbaric oxygen therapy can be provided. This means that oxygen will be administered in a high pressure chamber. Recompression on room air is also a very common method used to treat DCS. Here, the affected diver is subject to the same pressure they experienced at depth, while nitrogen and other gases go back into the solution form. Then, a very gradual decrease in pressure will cause the gases to be released by respiration. 

If you think you’re suffering from decompression sickness, get help right away. Regardless of your symptoms, this is a serious emergency.  DAN (Diver’s Alert Network) has a 24-hour hotline you can call in the event of dive related injuries like Decompression Illness and Air Embolism.

In the most severe cases the symptoms of decompression illness occur soon after or within one hour of the diver reaching the surface. It will be accompanied by dizziness, vomiting and breathlessness. If this is the case, urgent medical help is required; call the local emergency number for immediate aid. If the affected diver faints, CPR should be administered immediately.

If you or another diver suffers from severe pain that keeps progressing, but you don’t notice neurological symptoms, call for help. Be sure to obtain the affected diver’s medical history so you can provide it to emergency personnel.  

Finally, if you suffer pain that ebbs and flows over a series of days after diving, feeling perfectly fine sometimes and uncomfortable at others, you may have a mild case of DCS and it’s best to be evaluated by a doctor.  

Be sure to have the affected party’s dive history on hand, including the type of dive, depth, type of ascents, breathing gases, intervals between dives and safety stops. It is also essential to give an account of the first aid given and if there were any traumatic injuries that occurred during the dive.

Decompression illness can happen to anyone – even the most efficient diver. Getitng help right away is the best way to ensure a full recovery and prevent permanent damage from occurring.  

Category:
  • Dive Medicine
  • Decompression Sickness (DCS)
Keywords: dive medicine, decompression sickness (DCS), decompression illness, decompression sickness, arterial gas embolism (AGE), dysbaric injuries, type I dcs, type II dcs, bends, skin bends Author: Related Tags: Technical Articles