What do drivers call decompression sickness

When the diver starts to ascend, and the ambient pressure starts to drop, the gradient begins to reverse — first in fast compartments and then in progressively slower compartments. But if the degree of supersaturation is too great, the elimination of inert gases becomes disorderly.

Bubble formation does not always cause problems, but the higher the gradient, or degree of supersaturation, the greater the likelihood that signs and symptoms of DCS can occur. It is a dangerous misconception that measurable bubbles form after all dives and are of no importance.

But at the same time, it is a misconception that bubbles visualized in the blood stream in and of themselves signal DCS. The formation of gas bubbles during decompression represents a stress greater than is optimal and may lead to DCS.

It is best to follow conservative dive profiles to minimize the likelihood of bubble formation. The half-time compartment calculations are used to generate exposure-limit predictions for a range of hypothetical compartments. But in reality, the picture is much more complex.

Gas exchange is influenced by more than just the pressure-time profile. So while it is important for divers to understand the concepts behind calculating half-time compartments, divers must also keep in mind that a wide range of factors can influence gas uptake and elimination and effectively alter decompression risk. Menopause and memory: Know the facts. How to get your child to put away toys. Is a common pain reliever safe during pregnancy?

Decompression Sickness January 2, Research health conditions Check your symptoms Prepare for a doctor's visit or test Find the best treatments and procedures for you Explore options for better nutrition and exercise Learn more about the many benefits and features of joining Harvard Health Online ».

Sign Me Up. Print This Page Click to Print. Free Healthbeat Signup Get the latest in health news delivered to your inbox! Sign Up. Close Thanks for visiting. Maintaining a slow ascent rate greatly reduces the risk of all forms of decompression illness. Without getting too technical, the study measured the nitrogen saturation of tissues that become quickly filled with nitrogen, such as the spinal column.

The less nitrogen in his system, the lower the risk of decompression sickness. However, the pressure changes would depend mainly on the depth of the dive which is far greater than the outside of the body. Therefore, the gases can escape from the dissolved state and form bubbles in the various body tissues including the circulation where at first they plug the smallest blood vessels, but as they coalesce progressively larger vessels are affected.

Type I includes joint pain, skin rash, and marbling or localized oedema. Type II has more serious symptoms dominated by injury to the central nervous system mainly the spinal cord.

A year-old male, lorry driver and recreational diver. Normally fit and well apart from mild hypertension which was diagnosed a few weeks before his last dive. The diving conditions were described as very relaxed and well within the safety limits.

He denies any chest pain, pulmonary symptoms, back or abdominal pain or abnormality in the upper limbs. His friend who witnessed him confirmed that the patient had no seizures.

He woke up in the accident and emergency department when he was still able to move all four limbs. However, the abnormal sensation in both lower limbs was still present. Only after he came out of the chamber did he realize that he could not move his legs, the patient could not give an accurate timing and he became paraplegic T12 Frankel grade B, both knee and ankle reflexes reported to be present.

He also lost his bladder and bowel control. An echocardiogram was performed and was found normal. An MRI scan signa 1. MRI was again repeated 3 weeks after the injury. The MRI brain revealed an area of high signal lying high within the left cerebral hemisphere just supero-lateral to the left ventricle Figure 2. This is a FLAIR sequence MRI scan of the brain 3 weeks after the accident revealed an area of high signal lying high within the left cerebral hemisphere just supero-lateral to the left ventricle.

At 3 weeks after the injury, he started to show some flickers of movements in hip adductors, knee flexors and ankle dorsiflexors. He was reviewed in the outpatient clinic 20 months after the injury. He was able to walk indoors for approximately yards using two crutches. He had normal sensation of desire to defecate, and of defecation, and was able to feel and control micturition for a very short period of time.

A year-old male self-employed financial adviser , recreational diver, fit and well. He went through a tunnel on the same depth, from that moment he could not remember any thing until 3 days after the accident.

He was breathing air. According to his dive partner, the valve device froze in an open position and was continuously pouring air out, and he started to use the air regulator, he was behaving normally during his ascent BUT with NO stops. After he woke up he was not able to move any of his four limbs. On the third day after the accident, he could only recall incidents that happened 3 days after the accident.

He was told that he was tetraplegic from the beginning. His sensation was abnormal in both upper and lower limbs below C6. Both ankle and knee reflexes were absent. He was doubly incontinent.

He continued to have abnormal proprioception. He remained doubly incontinent. An echocardiogram was not performed in this case. An initial MRI scan of the brain obtained 3 days after the accident revealed an abnormally high signal in the white matter Figure 3. This had resolved on repeat MRI performed 8 weeks after the injury. Also, an MRI of the cervical spine performed 3 days after the accident showed an abnormally high signal at C3—4 level Figure 4 , which then disappeared on repeat scan 10 weeks later.

It depicts an abnormal high signal at the C3—C4 of the spinal cord. There is also a disc herniation at C5—C6 disc space but with No cord signal no axial images were taken at this stage.

It depicts a small right-sided disc herniation at C5—C6 level, some alterations in signal are present in the C5—C6 vertebrae, however; there is no evidence of cord lesion at this level. He was able to walk only very few steps indoors using the ankle foot orthosis and with the help of a walking frame.

He was emptying his bowel by digital stimulation and straining and his bladder with a suprapubic catheter.