1. Managing Decompression Sickness in Remote Locations
Joel D. Silverstein
Scuba Training and Technology Inc.
Sea Wonders LLC

2. What is The Bends? Decompression Sickness (DCS)
Treating DCI In Remote Locations
What is The Bends? Decompression Sickness (DCS)
It is the syndrome of joint pain, numbness, paralysis and other symptoms caused by the release of gas dissolved in tissues, which forms bubbles in the blood upon surfacing after a scuba or compressed gas dive.
Bubbles forming in tissues near joints cause the pain of classical “bends.” When high levels of bubble formation occur, complex reactions take place, which can cause other symptoms.
Copyright Joel Silverstein

3. History
“caisson workers” would stoop over at the end of the day after working on the footings of the Brooklyn Bridge
It got named “the bends” after the Grecian Bend, a fashion style of the times –

4. J.S. Haldane was enlisted by the Royal Navy to solve the problem.
Bends did not show up in diving until the late 1800’s when the McCliesh Diving company was doing salvage work on the HMS Rhone (1867) in the BVI
J.S. Haldane was enlisted by the Royal Navy to solve the problem.
His work lead to modern day decompression theory. –

5. Treating DCI In Remote Locations
When does DCS show up?
Symptoms and signs can appear within minutes to 48 hours after surfacing from any dive.
Severe cases can show symptoms “in-water” or immediately upon surfacing.
Copyright Joel Silverstein

6. First: Why worry about DCS?
Who dives in remote sites anyway?
Many land based expeditions involve diving
A large faction of diving is in remote areas

7. Many dives also involve altitude
Altitude diving presents a very complex planning process. The decompression tolerance is very small.
Highest altitude dive by Johan Reinhard
2002 Explorer’s Club Medal
Murat Egi’s dives to test tables, Turkey
Numerous dives in Lake Titicaca (9000’ msl) –

8. Logistics: Remote dive locations Carry minimal equipment
Access may be by hiking
Some by pack mule, jeep, light plane
For many, evacuation is just not an option
Pattern usually “scientific” or “recreational”
No chamber anywhere nearby
Even on well-supported operations
Such diving requires proper planning

9. Doux de Coly, France 15,000 foot cave push
Nearest chamber is 5 hours away
60 mfw depth
5 hour dive time. –

10. DCI Signs and Symptoms Disorientation Dizziness Fatigue
Hearing Difficulties
Muscle Pain
Numbness
Joint Pain
Paralysis
Skin Rash
Slurred Speech
Agitation
Tingling
Vision Problems
Weakness

11. Delaying Treatment % of Divers with Post-Treatment Residuals as a Function of Treatment Delay
Treat Early
Don’t Delay
The sooner the treatment the better the outcome –

12. Review: Treating DCS/DCI
Standard treatment:
Pressure. Prompt recompression is best
Oxygen
Hydration
Adjunctive therapies
Without pressure
Adjunctive therapies more to follow

13. How Recompression Works
Treating DCI In Remote Locations
How Recompression Works
A room is pressurized with air while a diver and a medical tender relax inside.
Most treatments are done at 60 fsw atm.
The diver breathes 100 % oxygen by a mask/hood, producing a surface equivalent of 280% oxygen.
Oxygen eliminates nitrogen in the body and maximizes bubble resolution.
Oxygenation of areas with compromised blood flow promotes healing. –
Copyright Joel Silverstein

14. Treatment Schedules
Average initial time at a hyperbaric facility 8 hours
Repeat oxygen treatments last 2 hours each.
Depending on DCI severity, treatments can be from 2 to 36 hours .
US Navy Treatment Table fsw 2 hours
US Navy Treatment Table fsw hours
COMEX 30 Treatment Table 100 fsw hours
US Navy Treatment Table 6a 165 fsw hours

15. Planning remote diving
Best approach to DCS is to prevent it
Very conservative decompression
Use plenty of oxygen or nitrox during decompression
Divers fit, well rested, and well hydrated
Be prepared to make diagnosis
Ensure DCS understanding by entire team
Use field neurological exam

16. Evacuation: The obvious approach
Every dive plan should include a method of evacuation if possible.
Plan this BEFORE leaving
Depends of course on the situation
DAN insurance will cover this
(You have to tell the Coast Guard it is an emergency.)
But if plan is sound it should not be difficult.

18. Portable chambers Some small enough to check on airline
Provide prompt recompression and O2
Pressurize with air, O2 by mask
Regarded as “hyperbaric stretcher,” but . . .
Somewhat expensive, but worth it

19. Portable Chamber 2 Small portable 1.6 ata chamber Max po2 is 1.6 atm
But ………
1.6 is better than 0 !
These are used for altitude sickness but work well for DCI

20. Putting it all into Action
Diver Surfaces.
Complains of pain.
Decompression was either:
Completed or Not Completed
Begin:
First Aid
Evaluation
Preparation for Evacuation or IWR –

21. Treating DCI In Remote Locations
General Care
Primary Survey
Airway - Breathing - Circulation
Do not leave injured diver unattended
If you can reach phone or help in under 1 minute -- breathing victim can be left
Shock
help maintain body temperature
keep victim hydrated
place 2x the insulation below body as above
Copyright Joel Silverstein

22. Treating DCI In Remote Locations
Field Neurological Exam
Check for:
numbness
tingling
weakness
mood change
paralysis
balance
loss of bladder / bowel
Confusion
Unconsciousness
Secondary Survey
Interview for:
Orientation
Memory of incident
Account for buddy
Feels any pain
Medications
Allergy
Emergency contacts
Copyright Joel Silverstein

23. Treating DCI In Remote Locations
Assessment Questions
Ask the diver to identify himself
Ask the diver to identify any problems
Ask the diver to recount the Dive Profile with special emphasis on significant events and changes in symptoms
Progress from simple to difficult subjects –
Copyright Joel Silverstein

24. Treating DCI In Remote Locations
Coordination
A combination of motor and sensory input.
After matching intention with performance, coordination is achieved.
A good indication of strength and coordination is simply to watch the diver walk.
Copyright Joel Silverstein

25. Treating DCI In Remote Locations
Romberg Test
The diver stands with feet together, arms extended in front with palms up, eyes closed
Observe for balance
check if the diver leans to one side
Be prepared to catch the diver if she falls
Copyright Joel Silverstein

26. Treating DCI In Remote Locations
Simple tests
Heel to Toe Walking
Diver walks a straight line heel to toe looking forward
Rapid Alternating Movement
Diver is asked to slap one hand on the other hand alternating palm up then palm down
Finger - Nose Test
Have diver alternate touching tip of his nose to your fingertip - Move your fingertip to various fields of vision
Copyright Joel Silverstein

27. Treating DCI In Remote Locations
Cranial Nerves
A deficit here, by definition, implicates an AGE or Cerebral DCS
Probably not a candidate for IWR unless there is really no other choice
Hearing is tested by rubbing the fingers together next to each ear
The senses of smell and taste are examined crudely, if at all
Copyright Joel Silverstein

28. Treating DCI In Remote Locations
Motor
To detect asymmetry, complete a bilateral comparison of specific muscle / groups before testing the next set
Severity may be defined as:
Partial weakness
Total absence of voluntary muscle movement
Copyright Joel Silverstein

29. Treating DCI In Remote Locations
Sensory
Minimize time and economize effort by:
Running vertically down the trunk
Around the limbs
Get a report after each pass of the exam
Copyright Joel Silverstein

30. Treating DCI In Remote Locations
Deep Tendon Reflexes
Deep tendon reflex ( DTR ) exam offers supportive information used to confirm or support other neurological deficits
Compare one side of the body to the other or upper to the lower limbs
Test the following with a reflex hammer:
Ankle Knee Biceps Triceps
Copyright Joel Silverstein

31. Initial Evaluation Results
Treating DCI In Remote Locations
Initial Evaluation Results
Primary Care Given
Evaluations performed
Conclude decompression sickness
Not AGE or Lung Expansion Injury
Patient put on 100% surface oxygen by demand mask
Copyright Joel Silverstein

32. No evac, no chamber: Two choices
Oxygen and adjunctive therapy
In-water Recompression

33. Adjunctive therapies Oxygen still the main modality
Need tightly fitting demand mask or rebreather
Symptoms often relieved
Hydration very beneficial
Not easy to do efficiently by mouth
IV saline, Ringer’s, etc.
Corticosteroids
Anticoagulants
N-SAIDs offer pain relief plus the ability to fight inflammation.

34. Adjunctive therapies in the works
Lidocaine: Looks good so far
Helps in cardiopulmonary bypass
Perfluorocarbon emulsion (“Oxygent”)
Injectable liquids that carry gas
Decompressed pigs significantly help in the evaluation process.

35. Adjunctive Therapy Results
When adjunctive therapies are used without recompression monitor the results carefully.
Document changes.
Conduct neuro exams every few hours to see progression.

36. UHMS Adjunctive Therapy Committee
Undersea and Hyperbaric Medical Society (UHMS) has committee to address these methods for efficacy
Contract with US Spec Ops
Test it on the military

37. In-water recompression
It works. Best with oxygen
IWR is done routinely by many groups
Advantage is that recompression is prompt
Within a 5 to 7 min window is optimal
But any time it might help
This can prevent symptoms from worsening
But you have to be prepared for it
Time to think about it is not when it happens
It is not a substitute for proper chamber treatment
But……. Pressure is pressure…..

38. Be prepared for in-water treatment . . . .
You will need some resources:
A qualified support team
Oxygen supply, regulators
Full Face Mask
Thermal protection
Rehydration and medication kit
Knowledge of what to do

39. Knowledge includes Diagnosis and assessment Treatment profiles
Communication techniques
How to rehydrate and medicate
Dealing with temperature
Oxygen tolerance techniques
What do do if there is a convulsion

40. How to Do IWR – Australian Technique
This technique may be useful in treating cases of decompression sickness in localities remote from recompression facility.
In planning realize therapy may take up to 3 hours.
The risks of cold, immersion and other environmental factors should be balanced against the beneficial effects.
The diver (PT) must be accompanied by an attendant.

41. Patient must be conscious. Have a location with a known bottom.
Reef, wreck site, embankment, etc.
Open ocean.
Shot line (weighted line)

42. Equipment Required
Full face mask with demand valve and surface supply system OR helmet with free flow.
Aga, KMDSI Supermask, Exo, Band Mask, etc.
Adequate supply of 100% oxygen for patient, and air (nitrox) for attendant.
Timing and depth devices – tender to have quality DC.
Wet suit [or dry suit] for thermal protection.
Shot with at least 10 metres of rope ( a seat or harness may be rigged to the shot).
Some form of communication system between patient, attendant and surface.

43. Treatment Protocol Table Aust 9 (RAN 82), short oxygen table
1. The patient is lowered on the shot rope to 9 metres, breathing 100% oxygen.
2. Ascent is commenced after 30 minutes in mild cases Type I, or 60 minutes in severe cases Type II, if improvement has occurred. These times may be extended to 60 minutes and 90 minutes respectively if there is no improvement.
3. Ascent is at the rate of 1 metre every 12 minutes.
4. If symptoms recur remain at depth a further 30 minutes before continuing ascent.
5. If oxygen supply is exhausted, return to the surface, rather than breathe air.
6. After surfacing the patient should be given one hour on oxygen, one hour off, for a further 12 hours. –

44. Treatment data: 30 minute treatment requires: 126 minutes in the water
Approx 90 cuft of oxygen for PT
PT is at 153% CNS dose, 293 OTU
6 hours of oxygen at surface by demand mask over 12 hours (1 on / 1 off)
Approx 250 cuft of oxygen for PT at surface –

45. –

46. The Tender Tender can be on air during PT treatment.
This is a no-stop dive however…….
Best to use a nitrox mix if available
If not – put Tender on 100% oxygen for 30 minutes after surfacing.
If treatment needs to be extended rotate tenders.
Use additional tenders to “drop in” and report results. –

47. Summary: DCS in Remote Locations
Plan to deal with DCS
Use a chamber on site
Evacuate to a chamber
Use oxygen and adjunctive therapies
Do in-water O2 treatment if necessary
Use conservative decompression and maybe you won’t need all this –