Review from Maganello

Question 1

What is the difference between T1DCS and T2?

Answer 1

T1 “The Bends”; usually pain related, but also includes fatigue, skin symptoms, and lymphatic manifestations.
T2 - neurologic, pulmonary, vertigo, hemodynamic compromise. These often happen <1hr.

Question 2

What are the T1DCS cases that are treated as T2DCS and why?

Answer 2

Cutis Marmorata: may be associated with more serious DCS, so treated as T2
Thoracic/Abd/Hip Pain: pain in ribs/vertebra or between ribs/sternum, which may originate from cord compression and indicates T2DCS.

Question 3

Patient presents to the surface with vertigo and tinnitus; what are distinguishing factors between Inner Ear DCS and Inner Ear Barotrauma?

Answer 3

Points Towards Inner Ear DCS:

• History of deep dive/ mixed gas breathing/ staged decompression
• Lack of DCS symptoms
• No Exam Signs
• Often occurs during decompression (isobaric counter diffusion)

Points towards Inner Ear Barotrauma:

• Rapid ascent/descent
• Air only dive
• Valsalva issues/ nasal and sinus issues
• barotrauma (TEED scale) on exam

Question 4

Describe Isobaric Counter-diffusion

Answer 4

When switching between gasses underwater, especially from N2 to He, it can take more time for nitrogen removal from tissues than for Helium to be taken up into tissues, causing overall supersaturation of the tissue and nitrogen bubble formation.

Question 5

Patient presents after a dive with substernal chest pain that is worst with inspiration and is not affected by movement. He has no shortness of breath, but does have mild muffling of his voice. He did not have any uncontrolled ascent, but did take a breath in while pushing the purge button and felt pressure in his chest at that time. What is the most likely diagnosis, next step in confirmation of diagnosis, and treatment?

Answer 5

Mediastinal Emphysema with voice involvement.
Chest XR
100% O2 at surface; can also consider recompression to 5-10fsw on 100% O2 for severe symptoms (voice changes)

Question 6

Patient presents with moderate shortness of breath and pleuritic chest pain. He has decreased breath sounds on the right and resonance to percussion on exam. How big should it be to needle-D this patient’s PTX, and what should you avoid doing?

Answer 6

> 3cm on CXR = “significant” = Needle-D

CONTRAINDICATED TO PUT INTO CHAMBER WITHOUT A CHEST TUBE.

Question 7

A UMO student was at the bottom of the pool during a hit and freaked out while breathing Air; he punched his instructor and bolted to the top. Afterwards, he went unconscious. What does he have and what should you do?

Answer 7

Arterial Gas Embolism - AGE
BLS/ACLS first, with 100% O2 by facemask
If stable, initiate a TT6, and extend to a TT6A if not fully resolved within 10 minutes.

Question 8

What are the requirements to produce a Barotrauma?

Answer 8

MARGE or GRAVE
Membrane (Vascular) Lined Space
Ambient Pressure Change
Rigid Walls
Gas Filled Space
Enclosed Space

Question 9

During descent, a patient has pain in her (#feminism) ear; she stops and attempts to clear, but struggles to do so. She is suffering from a…?

Answer 9

Squeeze - aka Barotrauma of descent.

Question 10

Patient has symptoms of Middle Ear Barotrauma with exam findings of TM erythema, and gross hemorrhage within the TM. What grade of barotrauma does he have?

Answer 10

Grade 3 - Diffuse redness, retraction of the TM, plus gross hemorrhage.

Question 11

Patient has symptoms of Middle Ear Barotrauma with exam findings of TM erythema, and retraction of the TM without hemorrhage. What grade of barotrauma does he have?

Answer 11

Grade 1 - Diffuse redness, retraction of TM without hemorrhage.

Question 12

Patient has symptoms of Middle Ear Barotrauma with exam findings of TM erythema, and slight hemmorhage within the TM. What grade of barotrauma does he have?

Answer 12

Grade 2 - Diffuse redness, retraction of the TM, plus slight hemorrhage.

Question 13

Patient has symptoms of Middle Ear Barotrauma with exam findings of a dark and bulging TM with a fluid level behind the ear. What grade of barotrauma does he have?

Answer 13

Grade 4 - Dark and slightly bulging TM due to free blood in the middle ear without perforation. A fluid level may be present.

Question 14

A Patient has a recent upper respiratory infection but decides to get a treatment for his upcoming surgery in the decompression chamber anyways. He has pain during descent, with transient vertigo and tinnitus, but no hearing loss or other signs of neurologic damage. The therapy is aborted and he has relief of his symptoms. Exam is unremarkable. What does he have?

Answer 14

Middle Ear Barotrauma - Note Grade 0 due to classic symptoms without signs.

Question 15

Patient has symptoms of Middle Ear Barotrauma with exam findings of perforation of his TM with free hemorrhage. What grade of barotrauma does he have?

Answer 15

Grade 5 - Free hemorrhage and perforation of the TM.

- Note this patient needs topical Abx for infection prevention.

Question 16

A Navy Seal completes a 2 hour dive on the Mk-25 and comes to the surface without issue. During the dive, he had some minor issues with equalization, but eventually cleared. Late that night, he wakes to excruciating ear pain and hearing loss. What happened and what is it called?

Answer 16

Draeger Ear - or Middle Ear Oxygen Absorption Syndrome
Patient had a middle ear space filled with O2 and the gas was absorbed by the vascular middle ear. This caused a negative pressure. The patient can clear their ears and clear the space.

Question 17

A patient with a recent URI and trouble clearing during a dive presents post dive with left sided facial droop, including the forehead, associated with left ear pain and mild tinnitus. The DMT comes to you concerned for AGE. What does the patient have?

Answer 17

No AGE. Patient has MEB with associated Facial Baroparesis also known as alternobaric Facial Palsy. Note that the patient has forehead involvement; this is dual innervated, and thus central involvement (e.g. AGE) would spare the forehead. This patient essentially has a Bells Palsy from MEB affecting the peripheral facial nerve.

Question 18

What depth must you reach for nitrogen narcosis to set in, and what might make this worse?

Answer 18

100fsw

increased depth and rate of descent

Question 19

What is the acronym for O2 toxicity and what does it stand for?

Answer 19

VENTID-C
Vision - Tunnel vision, blurring
Ears - ringing, roaring
Nausea - or vomiting
Twitching/tingling - face, lips, extremities
Irritability - also confusion, anxiety, anxiety
Dizziness - and loss of coordination
Convulsions

Question 20

Patient presents with headache, nausea, vomiting after a dive where they say they had a funny taste to the air. What is the diagnosis and what treatment table should be used for treatment?

Answer 20

Carbon Monoxide Poisoning. Severe Symptoms can include severe HA, Rapid HR, Mental Status Changes, or neurologic symptoms.
Patient should be treated on a TT5 for mild symptoms or TT6 for severe symptoms.

Question 21

When a patient is in cold water, what should they do to decrease heat loss in order to not become hypothermic?

Answer 21

HELP position; Heat Escape Lessening Position

Question 22

Does Heat Stroke cause you to stop sweating?

Answer 22

Sometimes; but this does not define it.

Temp >104 and neurologic symptoms such as CNS dysfunction.

Question 23

Which marine mammals utilize Tetrodotoxin for defense?

Answer 23

Puffer Fish

Blue Ringed Octopus

Question 24

How should you treat jellyfish stings?

Answer 24

Remove tentacles on patient with gloves
Remove nematocysts with rinsing with seawater
Immerse affected area in hot water (104-113 F) as long as tolerated to kill venom.

Question 25

A patient comes in with oral itching, burning, shortness of breath, and palpitations. He also has a urticarial rash on his neck and chest. He just finished a meal of tuna which he says tasted a little peppery, but otherwise normal. He has mild hypotension to 106/72. What is the most likely cause?

Answer 25

This is likely Scombroid. It is caused by inadequate refrigeration of dark or red-muscled fish leading to histamine and toxin production. It can be treated with antihistamines and steroids/epi if necessary. It is very rarely anaphylactoid in nature.

Question 26

We are hanging out and eating our spanish mackerel that Root and Ian caught and all of a sudden, we get abdominal pain, diarrhea, numbness of our extremities, and someone becomes paralyzed. What happened?

Answer 26

Tropical reef fish eat algae toxin (ciguatera) causing this illness. Usual onset is 15-30 minutes but within 12 hours. Treatment is vomiting, gastric lavage, BLS, and mannitol for neurologic symptoms. Mostly supportive treatment. Fish include Grouper, Snapper, Sea Bass, Surgeonfish, Parrotfish, Spanish Mackerel, Rock Cod, and Moray Eel.

Question 27

A patient was swimming in a lake in Iowa and comes out with itching and maculopapular rash. What is the cause?

Answer 27

Swimmers itch; schistosome larvae cause a cercarial dermatitis. Patient gets symptomatic therapy.

Question 28

A patient is swimming in the ocean and has painful itchy rash in the groin and legs. What is the cause?

Answer 28

Sea-Bather’s Eruption; aka sea lice. Caused by the larvae of the thimble jellyfish, treatment is symptomatic.

Question 29

What are the indications for a treatment table 5?

Answer 29

• Type 1 DCS, including full neuro on surface upon reaching 60fsw and complete relief at 10mins at 60fsw.
• Asymtomatic Decompression of less than 2.5 O2 periods
• Treatment of resolved symptoms after in-H20 deco.
• CO poisoning
• Gas gangrene
• Follow-up Treatments

Question 30

What are the indications for Treatment Table 6?

Answer 30

AGE
T2DCS
T1DCS symptoms without meeting indications for TT5
Cutis Marmorata
Severe CO poisoning
Asymptomatic Decompression >2.5 O2 periods or greater
Symptomatic uncontrolled ascent
Recurrence of Symptoms shallower than 60fsw

Question 31

What are the indications for a Treatment Table 9?

Answer 31

Selected CO/CN poisoning cases
Smoke Inhalation
Residual symptoms
Recommendation for UMO/DMO