Approved Indications Flashcards
HBO is considered adjunctive therapy for which indications?
Clostridial mycositis or myonecrosis
Crush injury, compartment syndrome, other acute traumatic perfusion injuries
Enhancement of healing in selected problem wounds
Intracranial abscess, actinomycosis
Necrotizing soft tissue infections
Refractory osteomyelitis
Delayed radiation injury
Compromised skin grafts and flaps
Thermal burns
Acute idiopathic sensorineural hearing loss
HBO is considered primary treatment for what indications?
Decompression sickness, air or gas embolism, carbon monoxide or cyanide poisoning, exceptional blood loss anemia
Def of DCS and causes
Formation of bubbles in tissues or blood upon reduction of environmental pressure.
Caused by reduction of environmental pressure. Inadequate decompression following exposure to increased pressure while breathing air
Manifestations and first aid for DCS
Sx depend on where bubbles form.
Type 1-pain only-skin and constitutional symptoms
Type 2 -serious, delayed , neurological Sx
Type 3 - DCS with AGE or VGE - pulmonary Sx “the chokes”
First aid
100% oxygen
IV fluids
Return to1 ATA if Sx occurred at altitude
Treraputic mechanisms and tx protocol for DCS
HBO shrinks bubbles
Increases pressure gradient of inert gases
Increases diffusion distance of oxygen into compromised tissue
Decreases reperfusion injury by blocking neutrophil attachment
Tx protocol
Earlier recompression = best outcome
Pain only gets table 5. Others table 6
Air or gas embolism def and causes
Air or gas bubbles in the blood vessels
Pulmonary barotrauma during a reduction in pressure which allows air to escape into the vasculature
Accidental IV air injection during cardiopulmonary bypass, hemodialysis, central venous catheter placement or disconnection, GI endoscopy, various surgical procedures.
Significant decompression illness with patent foramen ovale or with buildup of bubbles in pulmonary circulation.
AGE Sx and first aid
Arterial- immediate onset of Sx - loss of consciousness, confusion, focal neurological deficits, cardiac arrhythmias or ischemias. Variable depending on location of bubbles.
Venous- hypotension, tachypnea, hypocapnia, pulmonary edema, or cardiac arrest
First Aid - supplemental oxygen (maintains arterial oxygenation and creates a gas diffusion gradient. IV fluids. Supine position-NOT trendelenberg!! Left lateral decubitus for VGE
Therapeutic mech and tx protocols for AGE/VGE
Shrinks bubbles, increases diffusion distance of oxygen into compromised tissue, increases pressure gradient of inert gases (nitrogen)
Tx - immediate compression, table 6
CO and CN poisoning def and causes
Increased COHgb with history of exposure, acute or chronic. CO has greater than 200 x affinity for hemoglobin than oxygen. Fetal carb oxyhemoglobin will be higher than moms by 10-15%.
Caused by exposure from incomplete combustion; common sources are gasoline-powered engine exhausts, especially in enclosed, unventilated spaces; house fires; propane heaters
CO and CN Sx and tx
Headache, chest pain, ischemic changes on EKG, neuro changes, coma, increased COHgb lab value (confirms exposure)
Remove from source of exposure, give 100% oxygen
Therapeutic mechanisms for co/CN exposure
Increases pressure gradient of inert gases; increases diffusion distance of oxygen into compromised tissue (ESP brain and cardiac tissue). Causes vasoconstriction which reduces cerebral edema.
Half life of CO is 23 min breathing 100% at 3 ATA. 5 hrs 20 min on air 1 ATA. 1 hr 30 min 1 ATA oxygen
Exceptional blood loss anemia def and causes
HgB <6 with clinical s/Sx of anemia
Marked loss of RBC mass by hemorrhage, hemolysis, or aplasia
S/Sx of exceptional blood loss anemia and first aid
Altered mental status, ischemic EKG change, diarrhea from ischemic bowel, hypotension, diminished urinary output
100% oxygen
Therapeutic mech of HBO for exceptional blood loss anemia
Hyper oxygenation increases diffusion distance of oxygen into compromised tissue. Oxygen being delivered by plasma. Oxygen content of plasma is proportional to partial pressure. At 3 ATA, po2 =2000 mmHg
Clostridal myosotis and myonecrosis “gas gangrene” definition and causes
Infection of muscle tissue by anaerobic, spore forming, toxin-producing, gram +, encapsulated bacilli of the genus clostridium. Over 150 species, but most common is C. Perfrigens
Endogenous infection, caused from body contamination (bowel, etc), or an exogenous source, such as in a compound fracture.
S/Sx and therapeutic mechanisms of gas gangrene
Sudden and severe pain to area. Pronounced swelling and edema. Hemorrhagic bullae or vesicles may be present. Rapidly advancing (1-6 in/hr) tissue necrosis caused by alpha toxin production. Thin, serosanguinous exudate with sickly, sweet odor. Gas on X-ray appears as feathers.
O2 tension of 250 mmHg is necessary to stop alpha-toxin production by organism. Improves WBC fxn. Bacteriostatic (inhibits bacterial growth). Causes vasoconstriction which reduces edema.
Intracranial abscess, actinomycosis def and causes
Includes: cerebral abscess (pus in the brain); subdural empyema (pus between brain and meninges); and epidural empyema.
Result if sinus or bone infection of the skull. Usually bacteria introduced by trauma, surgery, or infection.
Actinomycosis usually caused by anaerobic bacterium Actinomyces israelii (found in nose and throat)
Intracranial abscess s/Sx and therapeutic mech
Draining sinus track to the skin or mucous membranes. Fever. Weight loss. Minimal, if any, pain. Immunocompromised host.
Increases diffusion distance in compromised tissue. Improves WBC fxn. Causes vasoconstriction which reduces edema
Necrotizing soft tissue infections def and causes
Acute infection of skin and subcutaneous tissues, by single strain or mixture if bacteria.
Caused by surgery or trauma (esp if foreign bodies introduced). Pt often compromised by diabetes, vasulopathy, or both.
What is Fournier’s gangrene?
Rapidly advancing, mixed bacterial infection of the groin.
Nec fasc therapeutic mech
Improves WBC fxn. Increases diffusion distance of oxygen into compromised tissues. Causes vasoconstriction. Encourages angiogenesis.
CRO def and causes
Long standing bone infection nonresponsive to debridements and abx therapy. NOT acute osteo.
Hx of exposed bone via fx, surgery, disease process. Often pt has factors that compromise responsiveness to infection.
CRO s/Sx and therapeutic mech of HBO
Previously documented osteo with appropriate debridement and abx therapy (gentamicin, tobramycin, anikacin - aminoglycosides commonly used). Hx of fracture with non-healing. Hx of healing and breakdown cycles. 3 phase bone scan, MRI, X-ray of osteo.
Enhanced leukocyte activity (increased WBC fxn). Increased diffusion distance of oxygen into comp tissue (commonly scar tissue)
Crush injury, compartment syndrome, and other ATAPI def and causes
Injury to an area of the body which has caused the blood flow to be interrupted. It causes severe hypoxia to tissue distal to the injury, which may or may not have been injured.
Usually caused by trauma, arterial rupture; compression; edema
S/sx of crush injury, etc
Edema, pain, reduced or absent pulses distal to site of injury, pallor, decreased cap refill
Therapeutic mech of HBOT in crush injuries, ATPI
Increased diffusion distance of oxygen into compromised tissue. Encourages angiogenesis. Causes vasoconstriction which reduces edema. Decreases reperfusion injury. Increases WBC fxn. Accelerates demarcation of non-viable tissues
Def and causes of selected problem wounds
A wound or ulcer that is failing to follow the normal reparative process due to inadequate oxygen availability.
Can have many causes but lack of blood flow is not life threatening or emergent.
Problem wound s/sx and therapeutic mech of HBO
Many manifestations. Likely to see extremity with hair loss; tight, shiny skin; pale color; cool temp; thickened toenails; evidence of previous wound healing; reduced cap refill; reduced pulses
Increases diffusion distance of oxygen into compromised tissue. Encourages angiogenesis. Improves WBC function.
Delayed radiation injury (soft tissue and bony necrosis) “strn and orn” def and causes
Tissue that is damaged by radiation
Caused by radiation, typically > 6,000 cGy
STRN/ORN s/Sx and therapeutic mech
Skin that is shiny, tight, appears thin, pale, without hair, commonly referred to as 3 H tissue - hypoxic, hypocellular, hypovascular. Possible fistulas, varying amounts of pain.
Increase diffusion distance of oxygen into compromised tissues. Encourages angiogenesis. Improves WBC fxn
Marx protocol
20/10 for prevention (pre-tooth extraction)
30/10 for existing ORN
Compromised grafts and flaps - def and causes
Skin grafts can be partial or full thickness. Flaps can be free, pedicle, random, axial pattern flaps. Comp. flap/grafts show signs and Sx of tissue death after replacement into the recipient area.
Surgical attempts at wound closure.
Comp flap/graft s/Sx and ther mech
Grafts will “slough” after only a few days <4 days. Pale, grey, purple, cyanotic and have poor cap refill.
Increases diffusion distance of oxygen into comp tissues. Encourages angiogenesis. Decreases reperfusion injury. Minimizes tissue loss.
Thermal burns def and cause
Any destruction of skin by heat.
Exposure to heat sources.
Thermal burns s/sx and ther mech
- Blistering and peeling of skin
- Copious exudates without odor
- Significant pain of partial thickness, no pain if full thickness
- Vasoconstriction reduces edema
- Increased diffusion distance of oxygen into compromised tissues
- Encourages angiogenesis
- Improves white blood cell function
- Minimizes surgical debridement and skin grafting.
Pt selection with thermal burns
- > 20% of TBSA
- Hands, face, feet or perineum
- Partial or deep partial – second degree – full thickness burned tissue cannot be resurrected but zone of stasis can be minimized.
Idiopathic Sudden Sensorineural Hearing Loss - IDIOPATHIC SUDDEN SENSORINEURAL HEARING LOSS
Patient selection
Patients with moderate to profound ISSHL (≥ 41 dB) who present within 14 days of symptom onset should be considered for HBO2. While patients presenting after this time may experience improvement when treated with HBO2, the medical literature suggests that early intervention is associated with improved outcomes. The best evidence supports the use of HBO2 within two weeks of symptom onset.
