portable hyperbaric chamber, are used for altitude sickness and decompression illness in remote areas. This document discusses the history, basics, indications, contraindications, complications, and applications of hyperbaric oxygen therapy (HBOT). It begins with definitions and the initial discovery of HBOT in the 1600s. It then covers the physics and physiology behind how increased pressure and oxygen concentration improves oxygen delivery to tissues. Common indications for HBOT include carbon monoxide poisoning, decompression sickness, gas embolism, and infections like clostridial myonecrosis. Complications can include barotrauma, seizures from oxygen toxicity, and fire hazards. Applications of HBOT include wound

1. Dr. SUDARSAN AGARWAL

2.  Definition
 History
 Basics(Physics & Physiology)
 Indications
 Contra Indications
 Details
 Complications
 Applications

3. Definition: The intermittent
administration of 100% Oxygen at
higher than atmospheric
pressure, i.e. where oxygen
dissolves in arterial blood plasma in
increased amounts.

4. .

5.  Initial discovery
 1662  Henshaw built first hyperbaric chamber
Henshaw’s
Domicilium

6. 1775 -Elemental
Oxygen by
Joseph Pristley

7. 1777 –Name Oxygen
was coined by
Antoine Lavoisier

8.  1870-Surgical use  Fontaine & Bert
Used for Wounds

9.  1889 – Moir.
Reduced mortality rate of decompression sickness
from 25% to only 1.6% per year.

10. Steel ball hospital
Timken Tank
Cunningham Sanitarium
$ 1,000,000

11.  1926 - Six-
story “steel
ball hospital”
Ohio.
 72 rooms at
pressures of 3
atm absolute.

12. 1960 –
 Pioneered the application of HBO to many medical
problems.
 Performs first surgery with HBO
• Discovered that Hgb wasn’t necessary for O2
transport

13.  Brummelkamp
discovered effects on anaerobes
 Bacteriostatic
 Treat gas gangrene (Clostridium
perfringens)

14.  In 60’s HBOT went out of practise because its use without
adequate scientific validation.
 Over last 20 years, animal studies, clinical trails and well
validated clinical efficacy has proved efficacy of HBO in
various ailments

15. .

16.  Oxygen is carried by blood mainly in two ways;
Haemoglobin
Plasma
 Haemoglobin carries majority of oxygen
 Plasma carries only minute amounts of oxygen.

17.  When we normally breathe air (with 21% O2) at
sea level pressure, most tissue needs of Oxygen are
met from the Oxygen combined to Hb, which is 95
% saturated.
 100 ml blood carries 19 ml O2 combined with Hb
and 0.32 ml dissolved in plasma.
 1 gm of hemoglobin carries 1.34ml of oxygen.
 15 gm of hemoglobin carries 20.10 ml of oxygen.

18.  Even if we increase the pO2 , hemoglobin cant
carry more oxygen as it is 100% saturated.
 Under barometric pressures, oxygen gets dissolved
into plasma and thus this dissolved plasma oxygen
is carried to different tissues.
 The higher pressure during hyperbaric oxygen
treatment pushes more oxygen into solution.

19.  Dalton’s Law 
 Increasing the proportion of oxygen in the inhaled gas
mixture increases its partial pressure
 Air at sea level is 21% O2
 HBO2 treatments use FiO2 100%

20.  Henry’s Law 
 Increasing the partial
pressure of oxygen results
in more oxygen dissolved in
the blood

21.  This additional O2 in solution is almost sufficient
to meet tissue needs without contribution from O2
bound to hemoglobin and is responsible for most
of the beneficial effects of this therapy.

22. Total Pressure
Ata
Content of Oxygen Dissolved in plasma (vol %)
 1
Breathing Air
0.32
100% Oxygen
2.09
 2
0.81
4.44
 3
1.31
6.80

24. 1. Oxygenation of Ischemic, Hypoxic Tissue - HBO
increases plasma and tissue oxygen tensions 10
times which helps tissues to maintain tissue
viability without RBC’s
2. Neutrophil Oxidative Killing - Neutrophils regain
ability to kill bacteria by generation of oxygen
dependent superoxides and peroxides.
3. Suppression of multiplication in bacteria- High
oxygen tensions suppress growth of
streptococcus and anerobes

25. 4. Augmentation of Antibiotic effectivenessIncreased oxygen tension allows oxygen
dependent active transport to bring in antibiotic
across bacterial cell wall.
5. Enhanced fibroblast function- prevents
unnecessary cicatrix formation.
6. Angiogenesis- Increased oxygen tension
increases vascular endothelial grow factor
function as well as secretion of matrix by
fibroblasts

26. .

27. Gas-bubble disease
 Air embolism
 Decompression sickness
Poisoning
 Carbon monoxide
 Cyanide
 Carbon tetrachloride
 Hydrogen sulfide
Infections
 Clostridial myonecrosis
 Other soft tissue necrotizing infections
 Refractory chronic osteomyelitis
 Intracranial abscess
 Mucormycosis

28. Acute ischemia
 Crush injury
 Compromised skin flaps
 Central retinal artery occlusion, central retinal vein occlusion
Chronic ischemia
 Radiation necrosis (soft tissue, radiation cystitis, and osteoradionecrosis)
 Ischemic ulcers, including diabetic ulcers
Acute hypoxia
 Exceptional blood loss anemia (when transfusion delayed or unavailable)
 Support of oxygenation during therapeutic lung lavage
Thermal injury
 Burns
Envenomation
 Brown recluse spider bite

29. .

30. *One absolute
contraindication is
Pneumothorax
Converts it into
Tension
Pneumothorax

DRUGS
Alcohol
 Nicotine
 Cis-platinum
 Doxorubicin
Bleomycin
Aromatic hydrocarbons
 Disulfiram
Steroids

31. Contraindications
*Claustrophobia
*Malignant tumors
*History of spontaneous
pneumothorax
*Acidosis
*Copd
*History of thoracic
surgeries
*Seizure disorders
*Pregnancy
*URT infection
*Hereditary spherocytosis
*Hyperthermia
*Optic neuritis
*Hypothermia
*Malignant tumors

32. .

33. •Two types of hyperbaric chambers:
Monoplace and multiplace

35. Monoplace

38. Multi place

43. Process of treatment
 Initial compression for 30 minutes
 Treatment for 90 minutes with air breaks (10
minutes every 30 minutes is standard)
 Decompression for 30 minutes
 All regimens use 100% O2
 Pressure  Most use 2.4 atm
 Maximum tolerated is 3 atm
 4 atm induces seizures

44. .

45. Mild problems :
 Claustrophobia (in monoplace chambers),
 Fatigue
 Headache.
More serious complications:
 Myopia that can last for weeks or months,
 Sinus damage,
 Ruptured middle ear, and
 Lung damage.
Major complication:
 Oxygen toxicity can result in convulsions, fluid in the
lungs, and even respiratory failure.

46. Middle ear barotrauma
 Middle ear barotrauma is the most common adverse effect
 As ambient pressure within the chamber increases, patient must be
able to equalize the pressure in his/her middle ear
 Boyles Law: A volume of gas in a closed space will decrease as
pressure increases P1V1=P2V2 Problems with air filled spaces
beneath dental fillings, middle ear and sinuses.
 If not, pressure gradient develops across the tympanic membrane.
Pain followed by hemorrhage or serous effusion develops
 Remedy: To teach valsalva maneuver
 Ventilated patients require myringotomy
 Prevention: Teaching patient auto-insufflation technique or use of
decongestants. If auto-insufflation fails, tympanostomy tubes are
placed.

47. Lung Barotrauma
 Elevated pressures
may damage
alveoli
 Alveolar
hemorrhage
 Hemoptysis
 Pneumothorax
 Pulmonary
interstitial
emphysema
Tension
Pneumothorax

48.  Eyes
 Lens deformation causes temporary myopia
 Progressive myopia has been reported in patients
undergoing repetitive daily therapy
 Reversible within 6 weeks of discontinuing treatment

49.  It is interesting that while o2 is necessary for life
in aerobic organisms, it is also toxic.
 1878 -Paul Bert: The Father of Pressure Physiology
observed convulsions and death in animals at a
constant 3-4 atmospheres of pressure.

51.  Broncho pulmonary
dysplasia
 Retinopathy of pre
maturity.(Retrolental
fibroplasi)

52.  Perfect set up for fire (especially monoplace)
 100% oxygen
 Highly pressurized
 Enclosed space
 Rare…
 50 deaths due to HBO2-related fires since 1980
 Must remove all flammable materials
 Fire safety protocol is essential
 Risk reduced in multiplace chambers
 Chamber pressurized
 O2 delivered individually via tight-fitting masks
 Attendants may enter in an emergency

53.  HBO2 is relatively expensive…
 Monoplace chamber > $150,000
 Most facilities have multiplace chambers, which
can cost millions
 Each 30 min costs ~ $170
 Average full course is 30 dives of 90 min
 Multiplace chamber for ~$15,300

54. .

55.  Carbon monoxide poisoning is the leading cause of
injury and death by poisoning in the world
 Affinity of CO for hemoglobin (forming
carboxyhemoglobin) is 200 times that of oxygen.

56.  Supplemental oxygen is first line therapy
 HBO causes carboxyhemoglobin dissociation to occur
faster than pure oxygen at sea level pressure.
Breathing Gas
 Air, 1 ATA
 Oxygen, 1 ATA
 Oxygen, 2.5 ATA
Mean Half-life
214 min
43 min
19 min

58. Decompression sickness (caisson disease or “the bends”) is attributed to
formation of nitrogen bubbles in the body on decompression.
Occurs in divers, miners and astronauts
•Diver resurfaces too quickly, Gas bubbles form in tissue
and blood and it Blocks lymphatics, veins and arteries
•Treatment of choice is HBO
• HBOT
• Reduces bubble size
• Corrects hypoxia

59.  Air embolism may be caused by sudden
decompression or ascent in diving, trauma like head
and neck injuries, high altitude accidents or may be
iatrogenic during a diagnostic or surgical procedure.
 Air emboli may lodge distally in the smaller arteries
and arterioles of brain and obstruct the flow of blood
resulting in ischemia, hypoxia and cerebral edema.
 The bubble may also act as a foreign body and start a
number of chemical reactions.

60.  HBO is the first line of treatment in these conditions.
Under hyperbaric conditions, oxygen diffuses into the
bubbles, displacing the nitrogen from the bubble and
into solution in the blood.
 HBO induced vasoconstriction inhibits air embolus
redistribution and decreases cerebral edema.
 High O2 counteracts the ischemic and hypoxic effects
of vascular obstruction.
 It also reduces blood sludging and improves WBC
function.

61.  Prompt recognition is important
 Anaerobic bacteria are especially sensitive to increased
tissue PO2.
 Diffused oxygen which raises capillary p02 levels at the
wound site, stimulates capillary budding and granulation
of new, healthy tissue.
 High O2 tensions
 inhibit clostridial α-toxin production.
 reversal of hypoxia-induced neutrophil function,
 enhanced macrophage interleukin (IL)-10
expression,and
 anti-inflammatory effects.

62.  Necrotizing Fasciitis and
Fournier’s gangrene
 Mucormycosis
 Anerobes
 Streptococci

63. Oxygen is required for angiogenesis (which is fostered by
the increased oxygen gradient), collagen deposition, reepithelialization, cellular respiration, and oxidative
killing of bacteria.
Decreased edema noted following hyperbaric treatment
allows better diffusion of oxygen and nutrients through
tissues while also relieving pressure on surrounding
vessels and structures.
In this light, HBO has been used for treating foot ulcers in
patients with diabetes, venous and arterial
insufficiencies, burn wounds, crush injuries, marginal
flaps, and skin grafts.

65.  Problem: Not all infections are anaerobic.

66. Foot wounds of patients with diabetes offer a
particularly difficult problem.
These patients often have an impaired immune
system, predisposing them to infections.
Blood supply to the wounds is hindered by large and
small disease.
The red blood cells are sticky and nonpliable, which
leads to capillary occlusion and distal ischemia.
Neuropathies render the foot insensate and impair
motor function.
This impaired motor function flattens the foot so that
the metatarsal heads become prominent and
promote further susceptibility to ulceration via
pressure.

67.  Intermittent hyperbaric therapy exposures have been
used to relieve temporary physiologic stress from acute
anemia
 Rarely used for this purpose
 May be useful when crossmatching incompatibilities and
religious beliefs prevent blood transfusions(Jahova)

68.  HBO is used in limited degree for acute traumatic
peripheral ischemia and suturing of severed limbs.
 Reduces infection and wound dehiscence and
improves healing
 Improves oxygenation to hypoperfused tissue
 Causes arterial hyperoxia causing vasoconstriction
and decreased edema formation.
 Also, intermittent pressure stimulates circulation and
reduces edema.
 Early use of HBO may reduce compartment
pressures enough to avoid fasciotomy.

69.  Trauma  Physiological response  Vasoconstriction 
Hypoxia
 Ischemia Swelling cuts off O2 circulation to the affected
areas

O2 leads to…
 Collagen deposition/synthesis
 Angiogenesis/epithelization
 AP
 Recovery time
 Performance
 Speeds recovery between workouts

70.  Damage to osteocytes from Radio therapy
 Does not affect necrotic bone
 Target is the viable bone and soft tissue
 Goal is to revascularize radiated tissues and to improve
fibroblastic density
 Healing process requires oxygen for:
 Differentiation of fibroblasts
 Synthesis of collagen
 20 “dives” before treatment/10 “dives” after radiotherapy
 2.5-2.8 ATA for 90-120 minutes.

72.  Pathophysiology
 Grafted or transplanted tissue may be healthy
 But… implantation site may be hypoxic
 Due to tissue bed disease, vasospasm, edema, infection
 Oxygen & nutrient supply compromised
 Must establish vascular connection for survival
 HBO2 Mechanism
 Improves tissue PO2
 Promotes angiogenesis
 Augments immune response & limits inflammation

73.  Among first studied uses of HBO2 (1960’s)
 Hypoxia increases the resistance of cancer to
radiotherapy.
 Increasing oxygen pressure in the tumor can aid
tumoricidal therapies
 Increase FiO2, increase ambient pressure
 Administration of radiation sensitizing agents

74.  Data are conflicting
 Handful of case reports suggest growth
(Promoting angiogenesis in tumor cells)
 Other reports suggest tumor suppression

75.  Loxosceles reclusa/ Necrotic arachnidism/ Violin Spider/ fiddleback
spider
 Routine treatment should include elevation and immobilization of the
affected limb, application of ice, local wound care, and tetanus
prophylaxis. Many other therapies have been used with varying degrees of
success including HBO , Debridement and antivenom
 Role of HBO is still controversial

76.  Characterised by impairment in social interaction, difficulty
in communication and restrictive and repititive behaviours.
 HBOT shown significant improvement in Speech and cognitive
awareness
 Still under study

77. 
 Gamow Bags, a rescue
product for high-altitude
climbers and trekkers, is
used for the treatment of
moderate to extreme
altitude sickness. By
increasing air pressure
around the patient, the
Bag simulates descents as
much as 7,000 feet

78.  2.0 ATA oxygen X 90 minutes
 wound healing
 comprised skin grafts
 thermal burns
 osteomyelitis
 crush injury/compartment syndrome
 2.5 ATA oxygen X 90 minutes
 nonclostridial gas gangrene
 necrotizing infections
 osteomyelitis
 radiation tissue injury
 3.0 ATA oxygen X 90 minutes
 carbon monoxide poisoning
 clostridial gas gangrene
*Average 90
min. HBOT
Rx = $300 $400
* Most
ailments
require
30-40
sessions

79. We can use HBO effectively in
• Air embolism
• Decompression sickness
• CO poisioning
• Radiation necrosis
• Chronic ulcers

80.  Miller s Anesthesia
 Ganong Physiology
 Harrison
 Sabiston
 Pubmed
 Wikipedia

81. The pressure is on to prove that it works.