Orthopaedics Flashcards
Why are pelvic fractures important in trauma?
- Represent high energy injury
- Commonly associated with vascular injury
What are complications of pelvic fractures?
- Organ injury eg GI, bladder, genital
- Neurovascular injury
- Skeletal injury including spine
What is the initial management of pelvic fractures?
- Primary and secondary survery simultaneously with volume replacement and resuscitation
- Minimal movement and immobilize - pelvic binder
- Permissive hypotension, early haemorrhage control, early blood products
When should pelvic trauma go to OT for packing?
- Co-existing major abdo/thoracic haemorrage
- Major bleeding from open pelvis
- Unstable with nil angio available
What is angio useful for in pelvic fractures?
- Bleeding from branches of iliac artery
- Isolated pelvic injury
What is the inital assessment and management of unstable spinal injury?
- assess c spine without removing collar
- Radiologically
- Clinically (NEXUS criteria) - GCS 15, not intoxicated, nil distracting injuries
What is neurogenic shock?
loss of sympathetic outflow resulting in a bradycardic, vasoplegic, hypotensive state (distributive shock)
What is the managment of acute spinal cord injury and neurogenic shock?
A - ?resp failure. Intubate with C spine precautions
B - supplemental O2, lung protective ventilation
C- Large bore access, resuscitate and optomize spinal cord perfusion
D- sequential neurological exam
What is cemented implant syndrome?
- hypoxia, hypotension, arrythmia and CVS collapse
- possibly fat embolism, air embolism or direct effect of the cement (causing release of inflamm mediators)
- typically occurs at cementation, prothesis insertion, reduction of the joint or deflation of the tourniquet
What is the management of cemented implant syndrome?
-Time limited event
- Increase FiO2
- treat RV failure i.e IV fluids, pulm vasodilators
- Inotropes to maintain RV contactility eg dobutamine and milrinone
What is the management of haemorrhage?
- Find the bleeding
- Stop the bleeding
- Rapid and effective restoration of blood volume
Initial measures are pressure, elevation, dressings etc
Invasive measures are sutures, tamponade, IR
Correct coagulopathy (avoiding hypothermia and acidosis)
What is the normal blood product replacement strategy?
1:1:1, PRBC, FFP, Platelets then reassess
Often then 1:1:10 PRBC, FFP, cryo
What parameters/blood tests need to be measured in critical bleeding?
- Temp
- Acid/base
- Hb
- iCa
- Platelets
- Fibrinogen
- APTT/INR
What is crush syndrome?
prolonged ischaemic and muscular damaged leading to rhabdomyolysis and reperfusion injury on release
What is the management of crush syndrome?
- Reduce fractures and splint joints in functional position
- Manage compartment syndrome if present
- Target normal pH and urine output
What are complications of crush syndrome?
Hypovolaemia
Hyperkalemia
Hypocalcaemia
Metabolic acidosis
Acute myoglobinuric renal failure
Acute compartment syndrome
What is compartment syndrome?
- When circulation and tissues within a closed space are compromised by increased pressure leading to ischaemia
What is re-perfusion injury?
- Biochemical change secondary to returning circulation to a previously ischaemic limb
- Increase systemic K, lactate, Co2, vasoactive substances
- causes reduction in systemic blood pressure
What is fat embolism syndrome?
- clinical diagnosis
- triad of: resp changes (dyspnoea/hypoxia), neurological abnormalities eg altered GCS, petechial rash
- higher risk in trauma, delayed immbolisation of fracture and conversvative mx
What is the management of fat embolism syndrome?
- supportive
- early aggressive resus
- Steroid use is controversial
- Usually resolves within 7 days
What are the issues with patients undergoing scolioisis surgery?
- Analgesia intra and post op
- PONV
- Antibiotic prophylaxis
- Blood loss
- Spinal cord protection (i.e MAP >60)
- Spinal cord monitoring
- Spinal surgery in prone position
How do you do spinal cord monitoring in scoliosis surgery?
- somatosensory evoked potnetials and motor evoked potentials
What is the usual managment of scoliosis surgery?
- TIVA (lower PONV and doesn’t effect spinal monitoring)
- Remifentail (avoid NMB so facilitate spinal cord monitoring)
- Pre warming to avoid hypothermia
- TXA to prevent blood loss
- Antibiotics
- Spinal cord monitoring
- Multi-modal analgesia
What are common intra-operative neuromonitoring modalities?
- Somatosensory evoked potentials
- Motor evoked potentials
- EMG
- EEG
What are SEPs and what do they monitor?
- Somatosensory evoked potentials
- Monitor posterior columns of the spinal cord
- Generally stimulate peripheral nerves eg ulnar, median and posterior tibial –> singal moves up dorsal column –> somatosensory cortex (where signal is measured)
- If there is a drop eg brown -sequard injury then can remove any recent surgical implants, increase blood pressure, give steroids, alter surgical approach
What are MEPs and what do they measure?
- Motor evoked potentials
- Measure vental columns of spinal cord
- Stimulus is over scalp, measure muscle contraction peripherally
- Measure the amplitude, latency and morphology of muscle contraction
- More sensitive than SEPs but also more effected by depth of anaesthesia and NMB
How does ketamine alter SEPs and MEPs?
increases them
How does dexmed/clonidine alter SEPs and MEPs?
- Decreases MEPs
- Nil change to SEPs
How does opioids alter SEPs and MEPs?
- Minimal effect
What are the local effects of arterial tourniquet?
- Distal limb ischaemia
- Direct compression of nerves and muscles under tourniquet
What are the systemic effects of arterial tourniquet?
- Increased SVR
- Increased circulating volume (due to smaller overall vasculature in which the volume resides)
- Increased CO2 post deflation –> increased MV if spont vent, increased cerebral blood volume
- small increase in potassium and lactate post deflation
What are the common complications with arterial tourniquets?
- Nerve injury (most common) - usually direct compression rather than ischaemia
- Muscle injury
- Skin injury (prep trapped against skin)
- vascular injury (may precipitate plaque rupture)
How should tourniquet pressures be set?
- Patient dependent
- Ideally only slightly higher than the limb occlusion pressure (40mm - 80mmHg higher)
- Clinically more often set to 100 + sys for upper limb and 150 + sys for lower limb
- Better than using a standard pressure for all patients
