Quiz - 34 - Diving Knowledge Workbook - Diving Physiology

[Pedro Burrito]

From the Diving Physiology Section of the PADI Diving Knowledge Workbook Version 2.02 © PADI 2009:

Objective 2.14 - Compare and contrast the various signs / symptoms of decompression sickness and air embolism.

Question 1

A symptom of air embolism may be ___, while two symptoms of DCS may be ___ and ___.

a. pain in the joints, fatigue / sudden unconsciousness

b. sudden unconsciousness / pain in the joints and fatigue

c. coughing of bloody froth / dizziness and confusion

d. cherry red nail beds / paralysis​

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Thank you for your patience while we try to give people something to discuss other than Covid-19 and/or Politics. I will post the answer covered by the spoiler tag later today.

 

[TMHeimer]

Do I detect a discussion? More than one possibly correct?

 

[Brett Hatch]

I went with (c), but was very close to going (b). Is one of these two partially correct and the other one fully correct?

 

[Zef]

I went with (c), but was very close to going (b). Is one of these two partially correct and the other one fully correct?

"C" is the more correct answer as unconsciousness is a possible sign/symptom for both types of DCI, not one or the other.

If the type of DCI is an AGE it can cause coughing and bloody froth/sputum, particularly if the embolism occurred in the lungs. Dizziness, confusion, loss of memory, and personality changes are among the signs and symptoms of DCS.

-Z

 

[Ukmc]

Spoiler: My opinion

We will see what the answer is, but b was pretty clear cut answer for me. I think sudden is the key. Also joint pain and fatigue are the most common symptoms of DCS.

 

[tursiops]

Spoiler: My opinion

We will see what the answer is, but b was pretty clear cut answer for me. I think sudden is the key. Also joint pain and fatigue are the most common symptoms of DCS.

Agreed.

 

[Aviyes]

"C" is the more correct answer as unconsciousness is a possible sign/symptom for both types of DCI, not one or the other.

If the type of DCI is an AGE it can cause coughing and bloody froth/sputum, particularly if the embolism occurred in the lungs. Dizziness, confusion, loss of memory, and personality changes are among the signs and symptoms of DCS.

-Z

The AGE itself does not cause the bloody froth. That would be some type of trauma to the lungs, that would then have caused an air embolism. Plenty of ways to get an air embolism that did not have an initial lung trauma.

 

[Brett Hatch]

The AGE itself does not cause the bloody froth. That would be some type of trauma to the lungs, that would then have caused an air embolism. Plenty of ways to get an air embolism that did not have an initial lung trauma.

Aha. I had forgotten what AGE actually stands for, and was thinking that it was a lung embolism, hence responding with (c), since coughing up blood is likely a lung problem. But the "A" in AGE stands for "arterial," so we would be looking for problems delivering freshly-oxygenated blood, and sudden unconsciousness is of course one of those. I stand corrected, thank you for clarifying!

 

[Pedro Burrito]

Spoiler: Answer

b. sudden unconsciousness / pain in the joints and fatigue

In air embolism, air bubbles escape directly into the pulmonary vein, are transported to the heart and then - most likely - to the brain. The bubbles begin to expand upon ascent and eventually block arterial circulation when they become too large to pass through the blood vessels. Much like a stroke, this blockage cuts off vital blood flow to the brain, usually resulting in almost immediate unconsciousness. Coughing of bloody froth is actually not a very common sign. On the other hand, DCS results from nitrogen elimination occurring so quickly - due to a reduction in ambient pressure - that it comes out of solution and forms bubbles. This condition does not occur immediately, but rather over time (taking usually 30 minutes or more). Although not fully understood, many believe that joint pain is a result of extravascular bubble formation in the ligaments and tendons of the joints.

 

[GJC]

Aha. I had forgotten what AGE actually stands for, and was thinking that it was a lung embolism, hence responding with (c), since coughing up blood is likely a lung problem. But the "A" in AGE stands for "arterial," so we would be looking for problems delivering freshly-oxygenated blood, and sudden unconsciousness is of course one of those. I stand corrected, thank you for clarifying!

Spoiler

It's not the oxygen that causes unconsciousness, it's bubbles that get stuck in arteries in the brain and blocking blood flow that causes unconsciousness.