HYPERBARIC THERAPY.pptx BY DR BHAWNA ESI

ANAESTHESIA

1. HYPERBARIC THERAPY MODERATOR: DR (Prof) VIJAY NAGPAL PRESENTER: DR BHAWNA GARG

2. contents Definition History Physiology of HBOT Indications Equipment for HBOT Preparation of patient for HBOT Complications Contraindications

3. DEFINITION- HBOT Hyper (increase) + baric (pressure) Hyperbaric oxygen therapy (HBOT) - the “intermittent, usually daily, inhalation of 100% humidified oxygen under greater than 1 atmospheric absolute (ATA) pressure The Committee on Hyperbaric Medicine definition – Patient is entirely enclosed in a pressure chamber and breathes 100% oxygen at a pressure > 1 atmosphere absolute (ATA). HBOT - The use of high-pressure oxygen as a drug

4. HISTORY 1662- hyperbaric air was used by Henshaw for the treatment of “affections of the lung”. He built a structure called the DOMICILIUM that was used to treat a multitude of diseases. The chamber was pressurized with air or unpressurized using bellows.

5. • In 1775, English scientist Joseph Priestley - groundbreaking discovery of oxygen • I n 1777, the term "oxygen" was introduced by the French chemist Antoine Lavoisier. • By 1789, Lavoisier and Seguin documented poorly understood toxic effects linked to concentrated oxygen, which contributed to growing caution around the use of hyperbaric oxygen therapy (HBOT).

6. 1937- Behnke and Shaw first used hyperbaric oxygen successfully for the treatment of decompression sickness sufferred by deep sea divers. In 1950's: The modern clinical application of HBO began, in parallel with an increased understanding of blood gas analysis and gas exchange physiology. In 1960's - 2 institutions preeminently pursued the clinical aspects of high-pressure oxygenation . Dr. Bakers from the University of Amsterdam developed the use of intermittent HBO, for the treatment of gas-gangrene.

7. Royal Infirmary of Glassgow, where various anesthetic and surgical aspects of HBO were applied and discussed. 1965: It was first used to assist wound healing when it was noted that burns of the victims of coalmine explosions treated with HB02 healed faster. Since 1970: Most of the instructional courses, research work and guidance have been provided by Under seas and Hyperbaric Medical Society (Headquarters in Kensington, Maryland). This medical organization publishes guidelines for hyperbaric oxygenation every 2-3 years.

8. PhysicS OF HBOT ATMOSPHERIC PRESSURE : A lso known as barometric pressure, is  the force exerted by the weight of air above a given point (at sea level, ambient pressure is 760mm Hg = 1 ATA) Hyperbaric pressure refers to greater than normal atmospheric pressure, hyperbaric chamber Pressure (THERAPEUTIC RANGE) :- Most use 2.4atm Maximum tolerated is 3 atm 4 atm induces seizures

9. 2. GAS LAWS: HENRY’S LAW: The solubility of a gas in a liquid is directly proportional to the partial pressure of that gas above the liquid, at a constant temperature.  In simpler terms, the more pressure there is on a gas above a liquid, the more of that gas will dissolve into the liquid.  The 3 main gases of concern in HBOT are oxygen, carbon dioxide, and nitrogen Oxygen - 0.024 Carbon dioxide - 0.57 Nitrogen - 0.012 In HBOT, this means that breathing pure oxygen under increased pressure allows more oxygen to dissolve in the blood plasma/tissue fluids, independent of hemoglobin, reaching tissues that may be deprived of oxygen. 

10. b.) BOYLE’S LAW: F or a fixed amount of gas at a constant temperature, the pressure and volume of the gas are inversely proportional to each other.  This means that if you increase the pressure on a gas, its volume will decrease, and conversely, if you decrease the pressure, the volume will increase.  Significance-This becomes important when gases are trapped in various cavities during compression and decompression of the patient.  In HBOT, increased pressure reduces the volume of gas bubbles, like those seen in decompression sickness or arterial gas embolisms & size of bullae, which can be beneficial in treating these conditions.

11. c.) FICK’S LAW: Rate of diffusion of a gas through fluids across semipermeable membranes. "the gas flow (volume of gas per unit time [V gas]) through a tissue or membrane is equal to the area (A) divided by the thickness (T) multiplied by the diffusion constant (D) times the difference in partial pressures (P1-P2) of the gas across the tissue or membrane."  In HBOT, increasing the pressure allows oxygen to diffuse more effectively into tissues, even those with reduced blood flow or swelling, potentially aiding in healing and addressing conditions like carbon monoxide poisoning and decompression sickness. 

12. d.) DALTON’S LAW: Increasing the proportion of oxygen in the inhaled mixture increases its partial pressure. Air at sea level has 21% O2 Gas used for HBOR has 100% O2

13. PHYSIOLOGY HYPERBARIC OXYGEN : Increased atmospheric pressure - increases blood oxygen content Completely denitrogenates airways & lungs Dissolved O2 content in plasma increases by 10 times Super saturates tissue fluids Movement follows laws of diffusion Body has mechanism to tackle hypoxia & hyperoxia Both conditions display release of similar cellular mediators (hypoxia & hyperoxia paradox)

14. HYPEROXYGENATION : An application of Henry's law- results from an increase in dissolved oxygen in plasma as a result of increased partial pressure of arterial oxygen (pO2). This additional O2 in solution is sufficient to meet tissue needs without contribution from 02 bound to hemoglobin and is responsible for most of the beneficial effects of this therapy . Useful in crush injury, compartment syndrome, flap salvage and acute blood loss anaemia .

15. 2.) DECREASE IN BUBBLE SIZE: Forces the gas bubble to dissolve in fluid Hyperbaric oxygen (100%), super - saturates the body fluids / plasma with oxygen. Volume of a bubble decreases directly in proportion to increasing pressure Useful in management of decompression sickness and arterial gas embolism. 3.) CELLULAR STIMULATIONS : vasoconstriction, angiogenesis, fibroblast proliferation leukocyte oxidative killing toxin inhibition & antibiotic synergy

16. VASCULAR EFFECTS : Vasoconstriction Angiogenesis Increase tissue delivery of oxygen by capillaries (despite vasoconstriction) Pre treatment with CO2 partially covers the vasoconstriction TOXIN INHIBITION : - eg Clostridial myonecrosis - Duration of effects - from few weeks to a year, sometimes life long

17. EFFECT ON CELLS: Improved mitochondrial function Stem cell activation (locomotion, transformation, proliferation) Neutrophil stimulation (locomotion, phagocytosis, ROS generation- oxidative killing) Stem and white blood cells- start forming new bone & skin cells, collagen production (bone formation & wound healing) Improved body antioxidant mechanism

18. Suppresses multiplication of bacteria (bacteriostatic) making them sensitive to antibiotics Vascular endothelial proliferation increases (angiogenesis) Fibroblast growth factors increases & fibroblast population increases Reduces half life of carboxyhemoglobin N = 4-6 hours, With HBOT at 3ATM = 23 minutes Can effectively reverse CO poisoning

19. REACTIVE OXYGEN SPECIES (ROS) & REACTIVE NITROGEN SPECIES (RNS): Clubbed as reactive oxygen species RNS- -NO -NO2 -ONOO ( peroxynitrite ) ROS- Superoxide anion (O2-) Hydrogen peroxide ( H2O2) Hydroxyl radical (OH) Singlet oxygen (O=O) Peroxyl radical (ROO) Alkoxyl radical (R-O) Lipid hydroperoxide (LOOH) Hypochlorous acid ( HOCl )

20. MECHANISM REFERENCE CLINICAL APPLICATION

21. PHYSIOLOGY 2.) NITROGEN (SEE-SAW GAS): Diffuses through alveoli to blood, into tissue fluid, cells & nearly equal amount diffuses back also. Nothing anywhere in body can break its strong bond (triple covalent bond)- INERT Content & concentration pressures follow normal laws of diffusion. Blood- dissolved & bound to plasma, fats cells- bound to cell membrane & membranes of organelles especially neuromuscular tissues N2 gas “narcosis” can happen with divers (Inert gas narcosis) who use compressed AIR cylinders in scuba suits.

22. NITROGEN NARCOSIS: use of compressed air and dive to excessive depths Signs and symptoms - Nausea Speech (divers blabber) Paralysis (diver diver’s palsy) Proprio (diverse stagger) sensory aspects (diver’s fits) Convulsion Impaired decision (diver’s euphoria)-- inert gas narcosis At What depths? Often begins affecting diverse at depths greater than 30 meters MECHANISM: likely related to the gas dissolving into lipid membranes, disrupting cell signaling Helium is used in deep diving mixtures because it lacks narcotic effects. RECOVERY: symptoms reverse upon controlled ascent to shallower depths and usually have no long-term effects.

23. DECOMPRESSION SICKNESS : 1.DESCEND Amount of dissolved nitrogen increases with increasing depth of dive 2. ASCEND • Rapid ascent lowers pressure on the diver's body. • Excess nitrogen leaves dissolved form in tissues. • Nitrogen forms bubbles in tissues.

24. This condition arises when nitrogen forms harmful bubbles in the bloodstream and tissue fluids. It typically occurs if a diver ascends too quickly after spending extended time at depth, especially when using multiple air tanks.

25. SIGNS & SYMPTOMS: Splitting headaches (intracranial & eye socket) Severe muscle pain (skeletal muscles) Stiff immobile joints (diver’s bends) Coughing and dyspnea (diver’s choke) Red rashes & itching (diver’s itch) Vomiting May go into shock, MI, arrhythmias

26. TREATMENT OF DECOMPRESSION SICKNESS: SEND THE BUBBLES BACK IN SOLUTION/ REDUCE THEIR SIZE REPLACE WITH OXYGEN (CONSUMABLE) ALLOW CONTROLLED N2 EXCRETION THROUGH LUNGS FULL ICU CARE IN HYPERBARIC CHAMBER The length of recompression therapy varies based on symptom severity, the patient's dive profile, the specific recompression method employed, and how the individual responds to treatment.

27. 3.) HYPERBARIC CO2 CO2 is vasodilator (enhances cochlear blood flow) Dangerous hypotension may happen This may help sparsely supplied areas or very small blood vessels/ vasculitic supplied areas Example- areas washed by endolymph inner ear Areas with end arteries Uses: As a pre-Med:5% carbon dioxide in oxygen on spontaneous breathing for 15 minutes followed by hyperbaric oxygen therapy very good for acute sensory neural deafness

28. INDICATION of hbot According to Undersea and Hyperbaric Medicine Society (UHMS) Air or gas embolism Carbon monoxide poisoning or carbon monoxide poisoning complicated by cyanide poisoning Clostridial myositis and myonecrosis (gas gangrene) Crush injury, compartment syndrome, and other acute traumatic ischemia Decompression sickness (“BENDS”) Enhancement of healing in selected problem wounds- Diabetically derived illness, such as diabetic foot, diabetic retinopathy, diabetic nephropathy.

29. 7. Exceptional blood loss (anemia) 8. Intracranial abscess 9. Necrotizing soft tissue infections (necrotizing fasciitis) 10. Osteomyelitis (refractory) 11. Delayed radiation injury (soft tissue and bony necrosis) 12. Skin grafts and flaps (compromised) 13. Thermal burns.

30. EQUIPMENT Prepare manifold of oxygen and air Hyperbaric chamber- monoplace & multiplace Humidifier- outside Monitor- display screen outside Defibrillator- outside Ventilator- machine outside Two-way speaker- outside & inside Port for circuit, iv sets, catheters to pass Flow control panel- outside ( all manufactured with spark free connections )

31. OTHER CHAMBERS Two other types of chambers are mentioned, although they are not considered HBOT Topical oxygen, or Topox : is administered through a small chamber that is placed over an extremity and pressurized with oxygen. The patient does not breathe the oxygen, nor is the remainder of the body pressurized. The patient cannot benefit from most of the positive effects of HBOT, which are systemic or occur at a level deeper than topical oxygen can penetrate Topox is based on the concept that oxygen diffuses through tissue at a depth of 30-50 microns. This method does not treat DCS, arterial gas emboli (AGE), or carbon monoxide (CO) poisoning.

32. 2. Portable "mild" hyperbaric chamber : These soft vessels can be pressurized to 1.5-1.7 atmospheres absolute (ATA). They are only approved by the FDA for the treatment of altitude illness. The number of these chambers has increased, as they are being used more commonly in off-label indications.

33. PREPARATION BEFORE HBOT

34. PAC: Referals - ENT- FOR MIDDLE EAR DISEASE DENTAL- DENTAL CAVITIES NEUROLOGY- FOR ANY SEIZURE DISORDER APPROPRIATE THERAPIST- FOR DRUG HISTORY PHYSICIAN/ PULMONOLIST- RO RULE OUT BULLAE & POSSIBILITY OF PNEUMOTHORAX

35. Cold and other symptoms: Patients with the symptoms of a cold or the flu, fever, cough, sore throat, runny nose, cold sore, nausea, vomiting or diarrhea are not helped by oxygen. HBO treatments may need to be postponed until symptoms have subsided. Smoking : Hyperbaric oxygen therapy will not be effective in patients who use tobacco in any form like cigarettes, pipe tobacco, and cigars, as well as chewing tobacco and snuff. Clothing (Moon & Grande): Patients are provided with 100% cotton gowns to wear during treatment. • No articles containing nylon or polyester can be worn in the chamber. Cosmetics: Cosmetics, hair spray, nail polish, perfume, or shaving lotion containing petroleum, alcohol or oil base are not allowed while in the HBO chamber. It is important to discuss all skin care products with the HBO technician, so they may assure safety.

36. COMPLICATIONS Ear barotrauma- pain, acute fluid/blood in middle ear, ear drum rupture Sinus barotrauma- pain and bleeding in paranasal sinuses Dental barotrauma (dental cavities)- stimulation of root nerves (pain), trapped air in cavities (fracture tooth) Pulmonary barotrauma- alveolar rupture, pneumothorax, ruptured bullae, tension pneumothorax ROS & RNS (reactive oxygen & nitrogen species)- pulmonary oxygen toxicity (Lorrain Smith Effect) Cerebral oxygen toxicity (Paul Bert Effect)

37. 6. Eye toxicity- temporary myopia 7. Hypertension- temporary mild/moderate 8. Cataract formation- prolonged HBOT 9. Fire / explosion 10. Clautrophobia

38. CONTRAINDICATIONS A.) ABSOLUTE: Untreated pneumothorax Patients on cisplatin, bleomycin, doxorubicin Disulfiram- blocks superoxide dismutase which is protective against oxygen toxicity B.) RELATIVE: Upper respiratory tract infection Chronic pulmonary obstructive disease Congenital spherocytosis Eustachian tube dysfunction Asthma Pregnancy Claustrophobia Seizure disorder Hyperthermia