Compartment syndrome/osteomyelitis Flashcards
Compartment Syndrome
general
Surgical emergency characterized byincreased tissue pressure within a closed fascial space, resulting in tissue ischemia
♂>♀; men < 35 years of age
Can occur in any muscle compartment:
Upper and lower extremities (most common)
Abdomen
compartment syndrome
common causes
Most common
Common causes:
Fractures
Long bone fractures (75% of cases)
Tibia (most common)
Humerus near the elbow (supracondylar fractures in children)
Severe contusions or crush injuries
Reperfusion injury after vascular injury and repair
Restrictive cast or dressing
Compartments
What system is at highest risk
Made up of muscles, blood vessels, and nerves
Covered by a tough membrane called fascia
Fascia
Resistant to expansion and stretching
Homeostatic pressure gradient
Blood flows from a high-pressure arterial system → low-pressure venous system
venous system at higher risk due to lower pressure
compartment syndrome
pathogenesis
Interruption of the homeostatic pressure gradient causes a disruption in flow and capillary perfusion pressure
Build-up and extravasation of fluid out of the capillaries worsens the pressure within the closed myofascial compartment
Distribution of oxygen and nutrients and removal of carbon dioxide is disrupted → muscle ischemia and necrosis
compartment syndrome
reversible/irreversible length of time for muscle and nerve damage
Reversible muscle injury: < 4 hours
Irreversible muscle injury: ≥ 8 hours
Nerve conduction loss: 2 hours
Irreversible nerve injury: ≥ 8 hours
copmartment syndrome
RF
Major surgical procedures (orthopedic repair, post-embolectomy, post-laparotomy)
Blunt trauma
Burns
Reperfusion injury
Crush injury
Fractures (long bones)
Tight casts or dressings
Ongoing intra-abdominal bleeding
Penetrating trauma (vascular injury)
Malignancy
compartment syndrome
S/Sx
6 P’s and 3 A’s
6 P’s of tissue ischemia - adults
Pain (worsening pain)
Earliest symptom
Typically out of proportion to the severity of the apparent injury
Exacerbated by passive stretching of the muscles within the compartment
Paresthesias (sensory loss occurs beforemotor loss)
Pallor
Poikilothermia-the inability to maintain a constant core temperature independent of ambient temperature
Paralysis
Pulselessness (late symptom)
3 A’s of tissue ischemia – children
Analgesia, agitation, and anxiety
compartment syndrome
compartent syndrome
normal pressure and
Dx
Intra-compartmental pressure monitoring is required
Needle connected to a transducer to measure pressures (stryker pressure monitor)
Normal compartment pressure: 0-8 mm Hg
Compartment syndrome:
Compartment pressure ≥ 30mmHg
Difference between the diastolic blood pressure and the compartment pressure of < 30 mm Hg indicates an increased risk of compartment syndrome
BP 100/50 and compartment pressure is 27…50-27 = 23 (positive for compartment pressure)
compartment syndrome
Tx
Emergency fasciotomy
Mainstay of treatment
Opening the fascial compartments to relieve the pressure
Should be performed within 1 hour of diagnosis
Procedure:
Long incisions release the pressure in the affected compartment and adjacent compartments
Wounds are left open, and a 2nd-look procedure for debridement is performed within 48–72 hours.
Wound closure within 7–10 days (may require skin grafting)
compartment syndrome
Osteomyelitis
general
Infection of the bone that results from the spread of microorganisms from the blood (hematogenous), nearby infected tissue, or open wounds (non-hematogenous)
Can be acute or chronic
Acute evolves over days or weeks
Chronic persists over months to years → bone ischemiaand necrosis, boneloss, and/or sinus tract formation
osteomyelistis
epidemiology
Adults vs children
Males > females
Non-hematogenous osteomyelitis is more common in adults
Hematogenous osteomyelitis is more common in children
Longbone osteomyelitis is the most common subtype in children
Vertebral (lumbar) osteomyelitis is the most common subtype in adults
Sternoclavicular and pelvic osteomyelitis are the most common subtype in IV drug users
osteomyelitis
Direct inoculation of bacteria due to
Non-hematogenous osteomyelitis
Surgery
Prosthetic devices
Trauma
Hardware forfracturefixation
Soft tissue infection
osteomyelitis
Polymicrobial:
Non-hematogenous osteomyelitis
Staphylococcus aureus (present in > 50% of cases)
S. epidermidis
Streptococcus
Gram-negative bacteria
Anaerobic bacteria
Causes of Osteomyelitis due to Risk Factors
no specific RF:
sexually active, no other RF:
pet bite:
IVDU:
Sickle cell:
neonates:
emphasis on neonates
osteomyelitis
patho
What region of bone is often affected
Poorly understood
Appears to be affected by several factors:
Host immune status
Underlying disease
Virulence of the organisms:
Adherence
Defense mechanisms
Proteolytic activity
Vascularity and location ofbone (metaphysis ofboneis commonly affected inhematogenousspread due to the rich vascular supply of thegrowth plates)
osteomyelitis
Key findings on this Xray
Irregularity of the soft tissue in the distal aspect of the big toe (white arrows) corresponding to the ulcer
Adjacent to this, the tuft of the distal phalanx shows features of osteomyelitis, with loss of the cortex and underlying bone destruction (circled on large image)
Small focus of gas in the soft tissues (orange arrow)
Prominent calcification of several of the digital arteries in the forefoot (yellow arrows)
osteomyelitis
