Path 3 Flashcards
Most Common Joints in ER?
1) Ankle
2) Wrist
3) Knee
4) Hip
5) Shoulder
6) Elbow
How many ankle injuries a year?
5 million in US
Most common type of ankle injury?
lateral sprain due to inversion, while walking or running
How to treat an ankle sprain?
PRICE Protection Rest Ice Compression Elevation
Ankle Fracture Etiology
5,600/year in US
- equally common in men & women
- young men
- late middle-aged women
Where is ankle fractured?
vast majority-malleolar fractures
majority-unimalleolar
Complications of Ankle Fractures?
- joint space disruption
- dislocation
- soft tissue/skin necrosis
- nerve injury
- arterial disruption
Loss of arterial blood supply is???
a surgical emergency
“dislocation pressuring skin needs reduction as soon as possible to avoid necrosis of overlying skin”
Wrist Injuries: How many?
Most common type?
- 25 million
- fracture of radius (or ulna or carpal bones) due to fall on outstretched hand
Do wrist injuries or ankle injuries cause fractures more?
Wrist
1.5 million/year
Most common type of wrist fracture?
Colles fracture, at the distal radial metaphysis, with proximal and dorsal displacement, creating “dinner fork” deformity
How many knee injuries a year?
1 million ER visits
100,000 ACL
Hemarthroses
blood in the joint
-ligamentous injuries of the knee
Epidemiology of Hip Fractures
- Common-310,000 in 2003, decrease each year
- Primarily in elderly (female 77, male 72)
- 2X more in women
- 1/3 more common in whites
Pathophysiology of Hip Fractures
- Weakening of bone with aging 90% of hip fractures in the elderly associated with a simple fall from standing positions
- Fall because femoral neck breaks
Symptoms of Hip Fractures
sudden onset of hip pain, before or after fall, and inability to bear weight
Signs of Hip Fractures
leg shortened and externally rotated if fracture displaced
Hip Fracture Risk
deep venous thrombosis in the leg
Low Back Pain
15 million visits
85% are idiopathic
non-idiopathic: intervertebral disc herniated, spinal mets, spinal infection, epidural abscess, hemorrhage, spinal fracture & ankylosing spondylitis
Lumbar Intervertebral DIsc Herniation
- middle-aged adult 30-50y/o
- typically with recurring episodes of low back pain
- 95% have sciatica
Sciatica
-Syndrome of pain +/- sensorimotor symptoms in the distribution of a sciatic nerve
-Pain in the lower back, buttock & leg, typically sharp and commonly in a single dermatome
+/- leg weakness
+/- numbness or tingling (typically unilateral)
90% due to herniation of lower lumbarsacral intervertebral disc
Straight Leg Raise Test
-for lower lumbar intervertebral disc herniation
-raise b/w 30-70 deg above level
Positive=pain in the dist. of sciatic nerve
Sen: about 90% Spec: about 25%
-if opposite leg causes pain
sen:25% spec:90%
Cauda Equina Syndrome
-compression causing combo of:
low back pain, sciatica, leg weakness, bladder dysfunctioin, saddle hypo-or anesthesia, fecal incontinence, sexual dysfunction
Bladder dysfunction
Cauda Equina Syndrome: Signs
-bladder distention
-decreased anal tone
-absent ankle, knee, or bulbocavernosus reflexes
-saddle anesthesia
-bilateral sciatica
>500mL urinary retention
NEUROSURGICAL EMERGENCY
Spinal Epidural Abscess
Rare
- risk: spinal surgery, recent trauma, immunosuppression, distal infection, IV drug use, diabetes mellitus & alcoholism
- 20% no predisposing factor
Back Pain, Fever
Drug-Seeking in ER
10% of patients
-opioid
Necrotizing Fasciitis
-rare acute progressive destructive infection of muscle fascia and overlying subcutaneous fat
“flesh-eating bacteria”
1) Infection typically spreads along muscle fascia due to poor blood supply (muscle spared)
2) Overlying tissue can seem unaffected
3) Area of erythema (w/o sharp margins), swelling, warmth, shiny, exquisitely tender
4) Pain out of proportion
5) Type 1 polymicrobial (aerobes + anaerobes)
Type 2 group A strep (or MRSA)
Risk Factors for Necrotizing Fasciitis
diabetes vascular disease immunosuppression trauma surger
Microscopic Pathology
coagulative necrosis w/acute inflammation (neutrophils & fibrin exudation) starting at the edge, +/- aggregates of bacteria (but not where neutrophils are)
+/- nuclear dust (from neutrophil breakdown)
+/- hemorrhage
Necrotizing Fasciitis Over 3-7 days
Skin: red to purple to purple with patches of blue-grey
- 3-5 days: skin breaks down with bullae
- frank cutaneous gangrene, involved area is anesthetic due to thrombosis of small blood vessels and destruction of superficial nerves
- anesthesia precedes skin necrosis
Top 2 sites for Necrotizing Fasciitis?
1st: legs
2nd: perineum
Necrotizing Fasciitis Type I
subcutaneous gas often present
Advanced Necrotizing Fasciitis
fever of 38.9 to 40.5 tachycardia hypotension malaise myalgias anorexia diarrhea
Diagnosing Necrotizing Fasciitis
history and physical
Treatment of Necrotizing Fasciitis
surgical debribement of necrotic tissue
broad spectrum abx
hemodynamic support
Prognosis of Necrotizing Fasciitis
bad (40% mortality)
Compartment Syndrome
- muscle groups divided into compartments formed by strong unyeilding fascial membranes
- increased pressure within a compartment compromises the circulation within that space
- acute, often following trauma
- chronic, athletes, insidious pain
Pathophysiology of Compartment Syndrome
- arteriovenous/arteriointerstital pressure gradient theory: a prerequisite for compartment syndrome is a fascial enclosure that prevents adequate expansion of tissue volume to compensate for an increase in fluid
- inadequate venous drainage results in tissue edema and a rise in interstitial pressure
- as compartment pressure rises, venous outflow is reduced and venous pressure rises, decreasing the arteriovenous pressure gradient
- arterioles collapse when tissue pressure exceeds end-arteriolar pressure, then arteriolar pressure is insufficient to overcome compartment pressure and blood is shunted away from compartmental tissues
When Does Acute Compartment Syndrome Occur?
- soon after sig. trauma (long bone fractures-leg/forearm)
- Nontraumatic: bleeding, thrombosis, vascular disease, nephrotic syndrome, extravasation of IV fluids, injectionof recreational drugs, prolonged limb compression
Acute Compartment Syndrome Symptoms
1) pain out of proportion to injury
2) persistent deep ache or burning
3) paresthesias (onset within 1/2-2 hours)
Acute Compartment Syndrome Signs
1) Pain w/passive stretch of muscles in affected compartment (early)
2) Tense comp. with a firm “wood-like” feeling
3) Diminished sensation
4) Muscle weakness (2-4hrs)
Normal Compartment Pressure
0 to 8mmHg
Pain with Compartment Pressure of?
20 to 30mmHg
Clostridial Myonecrosis
“gas gangrene”
-life-threatening necrotizing muscle infection from contiguous are of trauma or hematogenous muscle seeding from GI tract
2 Forms of Clostridial Myonecrosis
1) Traumatic - C. perfringens
2) Spontaneous - C. septicum
C. perfrigens virulence
1) alpha toxin - hemolytic
2) theta toxin - cholesterol dependent
Pathophysiology of Clostridial Myonecrosis
Trauma introduces bacteria/spores into deep tissue
-anaerobic if trauma impairs blood supply (low ox-red potential and acidic pH)
How long from trauma to necrosis
24-36 hours
Are neutrophils present in muscle necrosis?
no
Clostridial Myonecrosis Micrograph
- large box-car shaped gram + rods
- gram variable
Alpha Toxin
potent rapid irreversible decline in muscle blood flow and ischemic necrosis due to formation of occlusive introvascular masses of activated platelets, leukocytes, fibrin
-lack of perfusion increase anaerobic environment and contribute to growth
(activation of platelet fibrinogen receptor glycoprotein IIb/IIIa)
Skin over Clostridial Myonecrosis
-pale then bronze, purple/red
-tense and tender
Bullae form
gas bubbles
Clostridial Myonecrosis
tachycardia
fever
shock
multiorgan failure
Histopathology of Clostridial Myonecrosis
absence of inflammatory cells
Treatment of Clostridial Myonecrosis
aggressive and thouough surgical debridement with clindamycin and penicillin
Prognosis of Clostridial Myonecrosis
20% mortality - shock at presentation
spon: 67-100% mortality (malignancy/immunocompromised)
Rhabdomyolysis
condition of muscle necrosis and release of intracellular muscle constituents into circulation
Symptoms of Rhabdomyolysis
1) muscle pain, weakness, dark urine
2) muscle pain - proximal muscles (thighs shoulders), lower back, calves
3) stiffness/cramping
4) 1/2 have no muscular symptoms
5) malaise, fever, tachycardia, nausea, vomiting, abdominal pain
* **vairy, some asymptomatic
Signs of Rhabdomyolysis
- reddish brown urine
- muscle swelling with rehydration
- muscle tenderness
- muscle weakness
- no signs
3 causes of rhabdomyolysis
1) Trauma - crush
2) Exertion
3) Miscellaneous - toxins, meds, infection
Hallmark of rhabdomyolysis
elevation in serum muscle enzymes
creatine kinase
myoglobinuria
present in 50-75% rhabdomyolysis
+ blood dipstick, no cells in urine
myoglobin clogs renal tubules (acute renal failure)
