1. Steven Elsbecker D.O.
University of Nevada School of Medicine
January 18th 2012

3. 45 year old male with toe pain secondary to
gout presents to your ED. While establishing IV
access, the nurse forgets to flush the IV tubing
and the 10ft extension tubing that she decided
to use forcing a large quantity of air into your
patient’s vein.
He quickly becomes short of breath with
concurrent drop in O2 sats
Diagnosis?
Treatment?

4. Steven Elsbecker D.O. / Troy Aikman / Duffman
University of Nevada School of Medicine
January 18th 2012

5. Review our dive facility and procedures
Physics of Hyperbaric Oxygen Therapy (HOT)
Physiology of HOT
Indications
Review basic principles for using HOT
Disadvantages / Complications
Evidence for use in EM
To get ONE resident to implement HOT ONE
time in 2012

6. First hyperbaric chamber built in 1662 by British
clergyman Nathaniel Henshaw
Compressed manually with a bellows using
room air and did not reach pressures that had
any clinical significance
Up until 1955, much of hyperbarics remained
“of little clinical significance”

7. In 1967, the Undersea and Hyperbaric Medicine
Society (UHMS) was founded to help facilitate
the exchange of knowledge in the field
Eventually became the governing body for the
application of HOT

8. Two types of chambers
Monoplace
Just patient inside. Desired gas delivered to whole chamber
Multiplace
Can treat multiple critical patients at once. Nurse typically
inside. Desired gas mixture given to patients individually.

10. Duration is variable depending on indication
Pressurized to 2.0 – 2.2 ATA
FiO2 between 21 – 100%
Nurse in chamber with patients
Plasma TV with cable in the tank

11. Average bill generated for a single dive = $2600
Average repayment from Medicare is $360
Average number of dives required for a chronic
wound is 30
$78,000 for a diabetic foot ulcer
Just CUT IT OFF!!!

12. A neutron walks into Frankie’s and says “how
much for a Fink Bomb?” The bartender replies
“for you, no charge.”
Boyle’s Law
Charles’ Law
Henry’s Law
Ideal Gas Law

13. p1v1=p2v2
Useful when thinking about gas
embolic phenomenon, DCS

14. (p1v1)/T1=(p2v2) /T2
Used to explain temperature
changes when compressing or
decompressing patients.

15. P=KhC
Higher concentrations of a gas dissolved in
blood will yield a higher partial pressure.
Diffusion
Wound healing, DCS, CO poisoning

16. Hyperoxygenation
Fibroblast proliferation
Decreases gas bubble load
Vasoconstriction
Angiogenesis
Enhances leukocyte oxidative killing
Inhibition of Clostridial toxins
Antibiotic synergy

17. Hb saturation on room air 97-100%
Also have small amount of O2 dissolved in
plasma
Human tissue at rest requires approximately
250ml/min of O2
At 3atms, plasma concentration of O2 rises from
0.5 – 1.0 ml/dl to 6 ml/dl

18. Main physiologic force behind healing complex
wounds
More “healing” cells
Larger matrix to rebuild upon
Hunt TK, {ai MP, et al. The effect of varying ambient oxygen tensions on wound
metabolismand collagen synthesis. Surg Gynecol Obstet. Oct 1972; 135(4):

19. Poorly understood mechanism of action
Only ever studied in rats / mice
Important for complex wounds and
compromised grafts.
Limited applicability to EM
Knighton DR, Silver IA, Hunt TK, Regulation of wound healing angiogenesis-effect
of oxygen gradients and inspired oxygen concentrations. Surgery. Aug 1981;

20. Boyle’s Law
patmvatm = pHOTvHOT
As partial pressures in plasma increase, Boyles
law states that the volume of undissolved
gasses must decrease

21. Tina McProzac, a 35 yo pregnant female with known
history of bipolar disorder and SI is brought in by EMS
for AMS. She was found in her home after police were
called by a neighbor for her odd behavior. The patient
is unresponsive, but hemodynamically stable. Basic
AMS labs drawn at UMC are WNL. The female medical
student rotating at UMC then comments on the
patients beautiful shade of red lipstick.
At what CO-Hb level should you dive these
patients?
Are there other indications for diving them?

22. Hyperoxemia leads to vasoconstriction
O2 delivery(ml/min) = O2 carry(ml/dl) x Flow (dl/min)
No change in net O2 delivery
Decreased edema
Nylander G, Lewis D, Nordstrom H, et al. Reduction of postischemic edema with
hyperbaric oxygen. Plast Reconstr Surg. Oct 1985; 76 (4): 596-603

23. Enhances SOD
Augments oxidative destruction of
phagocytosed bacteria

24. Slows progression of necrotizing fasciitis
Limited use
Conservative management
Waiting for surgeon
Awaiting transfer for higher level of care
No studies to date on HOT in the setting of
severe C. diff infection

25. Generation of free radicals assists in bacterial
killing
Very limited studies done on HOT in the setting
of sepsis. Again, only rat models available.
Showed good outcomes.
Hill GB: Hyperbaric oxygen exposures for intrahepatic abscesses produced in
mice by non–spore-forming anaerobic bacteria. Antimicrob Agents
Chemother 1976; 9:312-317.

26. Who named the following gas law: p1v1=p2v2
Robert Boyle
Ross Berkeley
Jacques Charles
Amedeo Avogardo

27. Acute CO poisoning
Decompression Sickness
Gas Embolism
Necrotizing Fasciitis
Acute Traumatic Peripheral Ischemia
Crush Injuries
Acute Peripheral Arterial Insufficiency
Preservation of Skin Grafts
Refractory Osteomyelitis
Radionecrosis
Cyanide Poisoning
Actinomycosis
Diabetic Wounds of the Lower Extremeties
Acute Thermal Burns

28. Acute CO Poisoning
Decompression Sickness
Gas Embolus
Crush Injury / Compartment Syndrome
Central Retinal Artery Occlusion
Acute Thermal Burns

29. HOT not always indicated
Treatment indicated for CNS depression, severe
acidosis, CO-Hb > 20% or >10% in pregnant
females
Time to displace CO from Hb with room air,
100% NRB, and HOT is 300 minutes, 90 minutes,
and 32 minutes respectively
Halts lipid peroxidation by restoring cytochrome
function

30. Hyperbaric oxygen is used to DIFFUSE more O2
into plasma.
Increases total oxygen dissolved in plasma from
0.5 – 1.0 ml/dl up to 6ml/dl
O2 Content = 1.34 (HgB) (% Saturation) + PO2 (.003)
1.34 x 14 x 1.0 (18.76) + 760 x 3 x 0.003 (6.84)
Pigs

31. How many divers does it take to circumcise a
blue whale?
Four Skin Divers

33. As partial pressure of O2 and N2 decrease in
plasma, N2 and O2 dissolved in the tissues
diffuse back into the bloodstream
Severity depends on total amount of gas
dissolved in tissue and rapidity of ascent
Why Hyperbarics staff and SCUBA dive masters
have a limited number of allowable dives per
day

34. Breath Hold Divers?
Snorkelers?
Recirculating Tanks?
SCUBA?

35. Type I – musculoskeletal sxs, fatigue
Type II – CNS and cardiorespiratory depression,
shock
Type III – any spinal deficit, usually irreversible
Sxs 2/2 to bubble formation in vasculature
leading to micro infarcts.
BrubakkA, Neuman T. Bennett and Elliot’s Physiology and Medicine of Diving. 5th
edition. Great Britain. Elseiver Science Limited; 2003;Chapter 10

36. Increasing the partial pressure of dissolved
gasses in plasma will decrease the volume load
of undissolved gasses.
Balloon in a room
Gas Emboli and DCS

37. Rare, but very little treatment options
Nursing error
IJ Central line not in Trendelenburg
DCS
Pulmonary barotrauma
Vascular surgery
No absolute amount of gas needed. Dependent
on patient comorbidities and rapidity of buildup

39. Both have a myriad of complications
Edema is controllable with HOT without
compromise of O2 delivery
Decreases reperfusion injury
Flint: Cummings Otolaryngology: Head & Neck Surgery, 5th ed.; CHAPTER 79

40. Hyperoxemia causes vasoconstriction and
decreases edema
Proven efficacy with compartment and crush
Many types of edema, possibility of future
indications

41. Sudden onset painless monocular visual loss
Theory for HOT is that the small amount of
blood still getting to the retina can be
hyperoxigenated
Needs to be initiated within first 8 hours for
greatest efficacy
Visual improvement with HOT 82% vs 30% w/o
Beiran I, Goldberg I, Adir Y, Tamir A, Shupak A, Miller B, et al. Early hyperbaric
oxygen therapy for retinal artery occlusion. Eur J Opthamol. Oct-Dec
2001;11(4):345-50
Hertzog LM, Meyer GW, Carson S, et al. Central retinal artery occlusion treated
with hyperbaric oxygen. J Hyperbaric Medicine. 1992;7:33-42

42. HOT reduces inflammatory response, reduces
edema, and is protective against severe
superimposed infection.
2/2 to vasoconstrictive, improved wound
healing, and bacteriostatic/bacteriocidal
properties.
Hart GB, O’Reiley RR, Broussard ND, et al. Treatment of burns with hyperbaric
oxygen. Surg Gynecol Obstet. Nov 1974; 139(5) 693-6
Niezgoda JA, Cianci P, Folden BW, et al. The effect of hyperbaric oxygen therapy
on a burn wound model in human volunteers. Plast Reconstr Surg. May 1997;
99(6). 1620-5

43. Concept useful in DCS, air embolism, PTX
The use of HOT or a NRB yields oxygen rich,
nitrogen poor plasma.
The pockets of gas in the aformentioned
scenarios are mostly comprised of notrogen.
Larger gradient leads to quicker reabsorption of
gas pockets

44. Absolute
PNEUMOTHORAX
Disulfiram
Chemotherapeutic Agents
Relative
Asthma
Claustrophobia
COPD
Spherocytosis
High Fever
Pacemaker/ AICD
Pregnancy (no eveidence showing harm)

45. Barotrauma
Middle ear, Sinus, dental, and pulmonary
Cataract formation
Hyperthermia
Decreased seizure threshold

46. You are in a single coverage ER near the Pacific
coast, you have a chamber, what will you do?
Asymptomatic healthy 23 yo male pulled from a house fire with
no burns
45 yo male returning from SCUBA trip with decreased CNS fxn
and generalized weakness
33 yo male with nec fasc and a surgeon who says “this doesn’t
need surgery”
55 yo female frequent flyer with chronic pain asking for “the one
that starts with a D”
24 yo male construction worker with radial and ulnar fxs who is
complaining of increasing pain, parasthesias, and his hand
feeling cold

47. HACE / Altitude
Sickness
HAPE
Traumatic Cerebral
Edema
HOT in severe sepsis
Human shrinking??!?

49. Very useful tool, but costly and limited
indications
P1 – O2 diffused in plasma
P2 – increased partial pressure of dissolved
gasses yield smaller volumes of undissolved
gasses
P3 – hyperoxemia leads to decreased edema
Be aware that as you practice in different areas,
the common reasons for using HOT may change
depending on your surroundings

50. BrubakkA, Neuman T. Bennett and Elliot’s Physiology and Medicine of Diving. 5th
edition. Great Britain. Elseiver Science Limited; 2003;Chapter 10
Flint: Cummings Otolaryngology: Head & Neck Surgery, 5th ed.; CHAPTER 79
Beiran I, Goldberg I, Adir Y, Tamir A, Shupak A, Miller B, et al. Early hyperbaric
oxygen therapy for retinal artery occlusion. Eur J Opthamol. Oct-Dec
2001;11(4):345-50
Hertzog LM, Meyer GW, Carson S, et al. Central retinal artery occlusion treated
with hyperbaric oxygen. J Hyperbaric Medicine. 1992;7:33-42
Hart GB, O’Reiley RR, Broussard ND, et al. Treatment of burns with hyperbaric
oxygen. Surg Gynecol Obstet. Nov 1974; 139(5) 693-6
Niezgoda JA, Cianci P, Folden BW, et al. The effect of hyperbaric oxygen therapy
on a burn wound model in human volunteers. Plast Reconstr Surg. May 1997;
99(6). 1620-5
Latham E, Hare M, Neumeister, et al. Hyperbaric Oxygen Therapy. Emedicine
specialties. May 2010.
Auerbach: Wilderness Medicine. 6th edition. Chapters 75,77,78.

53. For a Bentley’s gift card…
What does SCUBA stand for?