Emergencies Flashcards
4 characteristic/ major criteria of fat embolism syndrome
- hypoxia
- CNS depression (confusion)
- pulmonary edema (SOB)
- petechial rash (axillary, conjunctivae, oral mucosa)
(lung brain skin)
Gurd’s diagnostic criteria
Tx and prevention of fat embolism syndrome
Non op: mechanical ventilation with high levels of PEEP
Prevention:
- early # stabilisation (within 24h) of long bone #
- decrease over-reaming of femoral canal
4 compartments of LL
anterior, lateral, superficial posterior, deep posterior
Pathophysiology of compartment syndrome
- local trauma and ST damage
- bleeding and edema
- increased interstitial pressure
- vascular occlusion (dec venous output, and arterial inflow)
- myoneural ischemia
Diagnosis of compartment syndrome
5Ps: pain out of proportion, parasthesia, pallor, palpable tense swollen compartment, blistering
late: pulselessness, paralysis
Compartment pressure (split catheter) measurements for
- polytrauma pt
- pt not alert/ unreliable
- inconclusive physical exam findings
look for perfusion pressure - delta p <30mmhg (DBP - compartment pressure) or absolute pressure >30mmhg
Mgx of compartment syndrome
This is a surgical emergency (muscle will die within 4-6h of ischemia)
- bivalving the cast, loosening circumferential dressings
- elevation to lvl of heart
- hyperbaric oxygen therapy
- OP: emergent fasciotomy of all 4 compartments (dual medial-lateral incision or single lateral incision)
Cx of compartment syndrome
- Volksmann ischemic contracture
- Permanent functional impairment
- Renal failure from release of myoglobin from muscle necrosis (rhabdomyolysis)
- Death
Red flags of back pain
INFECTION/CANCER - non mech pain: night pain, rest pain, night sweats - LOW, LOA, fever - prev ca, recent infection - <20yo, >55yo - hx of TB SPINAL # - trauma, osteoporosis SERIOUS INJURIES - cauda equina: saddle anaesthesia, bladder/ bowel incontinence, disturbed gait - neuro deficits - persistent pain, failure of tx - progressive SYDNROME - hairy patch/ cafe au lait spots (kids)
Classification of open fractures
Gustilo Anderson Classification
I:
- small <1cm
- low impact
- minimal ST injury
- mild contamination
II:
- 1-10cm
- moderate impact, ST injury, contamination
III:
- >10cm
- significant contamination, ST injury, high impact
(soft tissue coverage after formal debridement)
A: cover adequate
B: cover inadequate, periosteal stripping/ exposure of bone, severe comminution
C: arterial injury which needs repair
Empiric abx tx for open fractures?
Broad spectrum: benzylpenicillin + flucloxacillin + 1st gen cephalosporin
if heavily contaminated:
- add gentamycin/ metronidazole for gram neg cover
Important timing for open #?
must get into OT within 6 hours (GOLDEN hours)
- info increases after this time
How to differentiate live from dead muscle
4C: consistency, colour, contraction when stimulated, capillary
Live: turgid, pink/ bright red, contracts, bleed when cut
Dead: mushy, pale/ purple, absent contraction, no bleed when cut
Sx mgx of open fractures
Irrigation and debridement (within 6 hour and leave good bs)
- reexamine intra-op for NV function
- remove foreign material and dead tissue (medium for bacteria growth), remove comminuted fragments
- wound cleansing with saline
- repair vascular injuries
- amputate if non viable
- wound cultures
Stabilisation of #: reduce, maintain #
Early wound/ skin coverage since exposed tendons do not last long (by 48th hour)
Mgx of bone loss
Classification for closed fractures and soft tissue injury
Tscherne classification
C0: no ST injury
C1: superficial abrasion
C2: deep, contaminated abrasion with local contusional damage to skin or muscle
C3: extension skin contusion/ crushing or muscle destruction
Severity scoring to determine if limb is salvageable or to be amputated in trauma setting
Mangled extremity severity score (MESS)
- energy of injury
- shock group (BP)
- ischemia of limb
- age group
6 or less: salvage
else amputate
Complications in polytrauma
- compartment syndrome
- crush syndrome (traumatic rhabdomyolysis > myoglobinuria > acute renal failure)
- thromboembolism (DVT/ PE)
- tetanus
- fat embolism
- SIRS
- DIVC
- hypothermia
- 2nd hit phenomenon
Classification of shock
I (<15%): widened pulse pressure, normal RR, urine output, mental status
II (15-30%): dec pulse pressure, RR20-30, urine 20-30, mild anxiety
III (30-40%): BP drop, RR 30-35, urine 5-15, confused
IV (>40%): BP drop, RR>35, urine negligible, obtunded
Definitions
- SIRS
- ARDS
- MODS
SIRS: 2 or more of the following without evidence of infection
- temp >38, <36
- HR>90
- RR>20
- TW <4k, >12k, >10% immature
ARDS: berlin definition
- acute: 1w or less
- bilateral opacities consistent with pul edema
- PF ratio on minimum 5cmH20 PEEP
- not fully explained by cardiac failure or fluid overload
Multi organ dysfunction syndrome
- debt of progressive and potentially reversible physiologic dysfunction in 2 or more organs induced by an acute insult
electrolyte abnormalities in crush syndrome
Muscle cell die, they absorb Na, water and calcium > hypoNa, hypotension, hypoCa
Release K, myoglobin, creatine, CK > hyperK, ATN and AKI
Benefits of early stabilisation of #
Crucial for the healing of soft tissue and bone
- prevent further injury to surrounding soft tissue
- limit inflammatory response
- reduces infection spread
- facilitate tissue perfusion
- encourage early wound repair
- allows early mobilisation
principles in # stabilisation (in open#)
- should provide free wound access for repeated debridement and placement of local or distant flaps and bone grafts
- should not interfere with blood supply of # segments
- should be sufficiently rigid - allow early joint motion and at least partial weight bearing
options for # stabilisation
Simple 1/2 #: slings, splints, casts, traction
Internal fixation: screws, plates, intramedullary nails
External fixation
Internal fixation
- criteria in setting of open #
- pros
- cons
Criteria: minimal contamination, within 8 hours
Pros:
- good stabilisation
- allow early ROM
- facilitates # consolidation while preventing malalignment
- superior healing compared to external fixation
Cons:
- must strip soft tissue (avoid in grade 2 and above)
- cause partial loss in periosteal, cortical or intramedullary blood supply
- risk of infection
External fixation
- indications in setting of open#
- pros
- cons
Indications:
- v comtaminated/ high impact/ grade #
Pros:
- no foreign material in wound
- applied without additional soft tissue dissection (additional trauma)
- less risk of infection
- allow easy reassessment/ additional debridement
- easy dismantled if needed
Cons:
- risk of pins injuring neuromuscular structures or tie down muscle-tendons > interfere with joint motion and rehab
- pins may interfere with reconstructive procedures
- pin loosening risk: not as definitive as int fixation
- risk of pin tract infection
Options for wound coverage
primary closure - only in small grade1 wounds
wound left open for 2 days until dangers of tension and infection has passed
1. delayed primary closure
2. skin graft (no blood supply): split thickness, full thickness
3. flaps (has own blood supply): local/ pedicled vs free
> 4 types: skin, fasciocutaneous, muscle, musculocutaneous)
4. Vacuum assisted closure/ negative pressure wound therapy
MOA of VAC dressing
stimulate angiogenesis by stimulating granulation tissue
reduce edema and fluid - expedite healing
reduce size of wound
reduce bacterial count
Mgx of bone loss
- MOA of bone graft
- types of bone grafts
MOA
- osteoinduction (most imp): undeveloped tissue transformed to bone by inducing agent
- osteoconduction: transferred bone as scaffold for new bone to grow
- osteogenesis: from osteoblasts in transplanted autografts
Types of bone grafts
- autografts (same pt): cortical graft, cancellous graft, vascularised grafts
- allografts (cadaver)
- demineralised bone matrix
- synthetics
- bone morphogenetic proteins
Complications of open #
{LOCAL}
Early:
- neurovasc injury
- swelling, compartment syndrome
- infection
Late:
- malunion, non union, delayed union
- AVN
- Arthritis
- OM
- heterotrophic ossification
- growth disturbance in children
- joint instability/ stiffness
- complex regional pain syndrome
{SYSTEMIC}
Early:
- hemorrhagic shock
- sepsis
- fat embolism
- dvt/ pe
- ARDS
Late:
- MODS
- renal failure
causes of malunion
- failure to reduce # adequately
- failure to hold reduction during healing process
- gradual collapse of comminuted bone
Delayed union
- causes
- rx
causes:
- biological: poor blood stream, severe soft tissue damage, infection
- biomech: periosteal stripping, imperfect splint age, over rigid fixation
Rx:
- adequate immobilisation
- internal fixation
- bone grafting
Non union
- causes
- RF
Causes: SPLINTS
- Soft tissue interposition
- Position of reduction
- Location (lower third of tibia)
- Infection
- Nutrition (diseased bone, damaged vessels)
- Tumor
- Severity of injury
RF: smoking, DM, infection, old age, anaemia, NSAIDs
Types of non union
- Hypervascular/ hypertrophic
- due to premature weight bearing/ insecure fixation
- elephant foot, horse hoof, oligotrophic - Avascular/ atrophic
- due to poor BS, ends osteoporotic
- torsion wedge, comminuted, defect, atrophic pattern
RF of necrotising fasciitis
- Immune suppression: DM, AIDS, cancer
- Bacterial introduction
- IV drug use
- insect bites
- skin abrasion
- abdominal and perineal injury
Classification of Nec Fasc
T1: polymicrobial: non grp A strep, anaerobes, enterobac
T2: monomicrobial: grp A strep
T3: vibrio
T4: MRSA
How to assess likelihood of Nec Fasc
LRINEC scoring
>6: 92% likely
components:
- CRP
- WBC
- Hb
- Na
- Cr
- Glucose
Bedside tests for nec fasc
Finger test
- area infiltrated with LA
- 2cm incision incision to fascia: lack of bleeding, dishwater fluid
- push finger along deep fascia. if no resistance - nec fasc
Empiric abx for nec fasc
penG: strep/ clostridium
imipenem/ meropenem: polymicrobial
vancomycin: if MRSA suspected
RF for gas gangrene
Post traumatic - car accidents - crush injuries - gun shot wounds - burns - IV drug abuse Post op - bowel resection/ perforation - biliary sx Spontaneous - colon cancer
etiology: clostridial species (gram pos bacilli)
PE findings of gas gangrene
- sweet smelling odor
- swelling, edema, discoloration and ecchymosis
- blebs and hemorrhagic bullae
- “dishwater pus” discharge
- crepitus
- altered mental status
Abx for clostridium
Penicillin G and clindamycin (helps inhibit toxin synthesis)
Characteristic lab/ histo findings for gas gangrene
Lab: elevated LDH, WBC, met acidosis, renal failure
Histo:
- gram pos bacilli
- absence of neutrophils (lack of acute inflammatory response is hallmark of gas gangrene)
RF for osteomyelitis
- recent trauma or surgery
- immunocompromised patients
- illicit IV drug use
- poor vascular supply
- systemic conditions such as diabetes and sickle cell
- peripheral neuropathy
Classification of osteomyelitis
Hematogenous - most commonly in vertebrae - S aureus Non hematogenous - contiguous spread - direct innoculation: penetrating injuries, sx
Imaging Ix and findings for osteomyelitis
<2w: MRI (X ray findings lag by 2w)
>2w: X ray
In to out
- sequestrum: devitalised bone
- bone lucency
- sclerotic rim
- osteopenia periosteal reaction
- involucrum: formation of new bone
Mgx of osteomyelitis
abx
irrigation and debridement
- remove all devitalised soft tissue and sequestrum
- debride bone until punctate bleeding seen (paprika sign)
- hardware removal
- dead space mgx (graft/ flap/ VAC)
- instrumentation: ext fix, surgical fixation
- amputation
RF for septic arthritis
age>80 Med: DM, RA, cirrhosis, HIV crystal arthropathy endocarditis, recent bacteremia IV drug user recent joint surgery
Red flags suggestive of septic arthritis
fever appear toxic abnormal posturing for maximal joint volume inability to bear weight inability to tolerate PROM
What to send for in joint fluid aspirate
cell count with differential gram stain culture glucose lvl crystal analysis
WBC>50k: septic arthritis
>1K in prosthetic joint
