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
