Hyperbaric Oxygen Therapy PDF

Hyperbaric Oxygen Therapy https://www.youtube.com/watch?v=78PXByMI5J8  O2 present in blood Bound to Dissolved in hemoglobin plasma 1.5 % 98.5 %  O2 dissolved in plasma Is directly proportional to the PO2 of t...

Hyperbaric Oxygen Therapy https://www.youtube.com/watch?v=78PXByMI5J8  O2 present in blood Bound to Dissolved in hemoglobin plasma 1.5 % 98.5 %  O2 dissolved in plasma Is directly proportional to the PO2 of the blood Hyperbaric Oxygen Therapy (HBO) What is HBO? — Therapeutic use of oxygen in which the patient is entirely enclosed within a chamber and breathing 100% oxygen at a pressure greater than sea level (1 atmosphere absolute) — HBO therapy conducted under pressure between 2-3 ATA — Chamber pressure should be at least 1.5 ATM to be considered hyperbaric. Indications for HBO Therapy — Acute conditions ◦ Decompression sickness ◦ Air or gas embolism ◦ Carbon monoxide and cyanide poisoning ◦ Acute traumatic ischemia (compartment syndrome, crush injury) ◦ Acute peripheral arterial insufficiency ◦ Intracranial abscesses ◦ Crush injuries and suturing of severed limbs ◦ Clostridial gangrene ◦ Necrotizing soft tissue infection ◦ Ischemic skin graft or flap Indications for HBO Therapy (cont) — Chronic conditions ◦ Diabetic wounds of the lower extremities and other nonhealing wounds ◦ Refractory osteomyelitis ◦ Actinomycosis (chronic systemic abscesses) ◦ Radiation necrosis (HBO as an adjunct to conventional treatment) Effects of HBO — On respiratory system How HBO can impact respiratory system? — Hint: remember the gas laws? — ( Paid TV can be good)  1-Lung Volumes — Reduce the size of the air bubbles in the body ◦ Air Embolism ◦ Decompression sickness — Boyle’s Law — 100% oxygen at 3 atmospheres for 3 hours results in seizure ◦ Exposure is limited to 90 minutes at 3 atmospheres — 100% oxygen at 2 atmospheres for six hours results in cough, decreased vital capacity, substernal chest pain, and areas of patchy atelectasis ◦ At 2 atmospheres exposure is limited to 2 hours  2-Alveolar and Arterial PO2 — Used to increase the amount of oxygen carried in plasma in the blood — Dalton's Law (Increase in partial pressure of oxygen dissolved in the arterial blood) ◦ The total pressure of a gaseous mixture is equal to the sum of the partial pressures of its components — Henry’s law (The physical effect of an increased pressure) ◦ The amount of gas dissolved in a liquid is directly related to the partial pressure of the gas above the liquid  Dalton’s Law — PAO2 = FIO2(Pb - PH2O) - (PaCO2/0.8) — Absolute pressure at sea level = 14.7 psi or 760 mmHg — The PAO2 at 1 atmosphere is : ◦ 0.21(760 - 47) - (40/0.8) = 100 torr — The PAO2 at 2 atmosphere is : ◦ 0.21(1520 - 47) - (40/0.8) = 333 torr Henry’s Law — PaO2 at 1 ATM is 100 mmHg, and at 2 ATM is 333 mmHg — O2 solubility is 0.003 vol% for every 1 mmHg PaO2 ◦ Vol% = ml of O2/100 ml of blood or ml/dl — For 100 mmHg à 0.3 vol% (100 x 0.003) — For 333 mmHg à 1 vol% (333 x 0.003) — This increase the carrying capacity for O2 Cont. — 100% oxygen at 2 or 3 atmospheres, forces enough oxygen to dissolve in the plasma to meet metabolic needs. — Normally the body needs 5.0 vol% of oxygen. — 100% oxygen at 3 atm = 6.5 – 7 vol%. — 100% oxygen at 2 atm = 4.4 vol%. CO Poisoning complications — In a closed space, the individual will develop cerebral hypoxia in 3 - 4 minutes — 50-60% CO concentrations: ◦ Tachycardia, Tachypnea, Hypertension , Altered judgement, Confusion, Disorientation — Concentrations over 70%: ◦ Severe hypoxia and permanent brain damage and death  Treatment — For carboxyhemoglobin levels < 25% ◦ 100% oxygen à decrease blood CO levels 50% in about 50 minutes — For carboxyhemoglobin levels > 25% ◦ Hyperbaric Oxygen — Carbon monoxide poisoning ( CO) ◦ Room Air à 10 hours ◦ 100% O2 à 3 hours ◦ HBO at 3 ATM à 1 hour 3- HBO and Gas Temperature — The chamber should be monitored and ventilated to eliminate the heat Gay-Lussac's law:ase More pressure More heat  4-WOB — Increasing the partial pressure à increase the gas density à increase WOB à monitor your patient Vascular Effects EFFECTS OF HBO — 1-Vasoconstriction High O causes generalized vasoconstriction and a small drop in 2 cardiac output — Peripheral vasoconstriction reduces blood flow to the tissues and increases peripheral resistance ◦ There is no impairment to the tissues, since the elevated PaO2 more than normal, compensates for the reduction in blood flow — Vasoconstriction has not been found to occur in hypoxic tissues such as chronic skin ulcers, and therefore, these tissues may receive proportionately more blood flow during HBO 2-Neovascularization — As long as the exposure to HBO is intermittent, the regenerating cells receive the oxygen they need, and the macrophages continue to stimulate the growth of new vessels — Oxygen also improves collagen synthesis by fibroblasts — HBO has been found to speed the healing of skin grafts/flaps, wounds, burned, and irradiated tissues Hyperbaric oxygenation accelerates prosthetic rehabilitation of lower limb amputees. — These findings highlight the increasing validity of this procedure after limb amputation, which should be confirmed by further research in multicenter studies involving a larger number of respondents. http://www.ncbi.nlm.nih.gov/pubmed/23789564 Immune Effects EFFECTS OF HBO  Inhibition of the Growth of Anaerobic Microorganisms — The growth of anaerobic, facultative, and aerobic microorganisms is inhibited when the microbes are subjected to an hyperoxic environment — O2 also improve the leukocytes functions ◦ Used to treat gangrene Equipment Equipment › HBO champers can be Multiplace and Monoplace › Mainly, only one gas is used. › Outer shell is constructed from steel and clear double-layered acrylic Monoplace › The monoplace chamber accommodates a single person for each treatment › Most unites are mounted on wheels for portability. › During therapy, the oxygen concentration is kept at 100%.No need for the patient to wear mask › Special ventilators and monitors should be used due to high oxygen percentage and pressure Multiplace › Used for 2-13 patients › Pressurized with air and the patient is provided with supplemental oxygen via mask, head tent, or endotracheal tube › Has main chamber for patient and small chamber for providers to enter and leave without altering pressure. › Patient may breath air every 20 min to rest and avoid Oxygen toxicity. Contraindications for Hyperbaric Oxygen  Absolute Contraindications › Untreated Pneumothorax › Untreated Pneumomediastium Relative Contraindications Complications of Hyperbaric Oxygen  Possible Complications › Ear or sinus trauma › Tympanic membrane rupture › Pneumothorax specially with Asthma or COPD › Oxygen Toxicity › Fire › Sudden decompression Mixed Gas Therapy Nitric Oxide Therapy › Used as a pulmonary vasodilator to treat persistent pulmonary hypertension on the newborn › Initial therapeutic dose is 5 to 80 parts per million › Commonly administered with INOmax , INOvent. Nitric Oxide Therapy cont. INOmax INOvent Nitric Oxide Therapy cont. › Dangers: › NO2 › Rebound vasoconstriction › (Don’t wean too fast!) › Method of action: › Short-acting › Delivered directly to lung Helium-Oxygen (Heliox) Therapy › Administered in the Treatment of Obstructive Airway Diseases › Low density of gas improves ability of gas to move around obstruction › Clinical application: › Exacerbation of asthma › Treatment of postextubation stridor › Treatment of refractory croup › Treatment of severe airway obstruction in chronic bronchitis and emphysema Helium-Oxygen Therapy (Cont.) › Available concentrations: › 80% Helium and 20% oxygen › 70% Helium and 30% oxygen › 60% Helium and 40% oxygen Helium-Oxygen Therapy (Cont.) › Can be administered through an endotracheal tube or well-fitted nonrebreather › Actual flow: due to low density of gas oxygen flowmeters are not accurate › Correction factors used to determine actual flow rate of gas: › 80:20 – 1.8 × liter flow › 70:30 – 1.6 × liter flow › 60:40 – 1.4 × liter flow Activity You are asked to set up a large-volume nebulizer for the treatment of a pt. with an acute asthma exacerbation. The attending physician asks you to use an 80-20%heliox gas mixture as the driving gas for nebulizing the β2-bronchodilator. What is the actual flow of gas being administered to the Pt. if the set flow on the o2 flowmeter used is 10L/min? Carbon Dioxide (Carbogen) Therapy › Not common but Used to treat hiccups and carbon monoxide poisoning and in prevention of washout of CO2 during cardiopulmonary bypass › Supplied as 5% carbon dioxide and 95% oxygen or 7% carbon dioxide and 93% oxygen › It can be administered to patients with nonrebreathing mask connected to a reservoir bag. Monitoring Carbon Dioxide Therapy › Blood pressure › Patient pulse › Respiration › Mental status › If decreases or increases are observed, therapy should be stopped immediately