Anesthesia for Orthopedic Surgery

Report
David Hirsch M.D.
“There is a
fracture, I need to
fix it.”
(http://www.yout
ube.com/watch?v
=3rTsvb2ef5k)
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none
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Special considerations
Hip Surgery
Knee Surgery
Upper Extremity
Spine Surgery
Peripheral Nerve Blocks
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Bone cement (polymethylmethacrylate)
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Binds prosthetic device to patient’s bone
Can cause embolization of fat, bone marrow, cement
and air into femoral venous channels
 Most frequently with femoral prosthesis
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Bone Cement Implantation Syndrome
 Hypoxia – increased pulmonary shunt
 Hypotension
 Dysrhythmias- heart block and sinus arrest
 Pulmonary hypertension – increased PVR
 Decreased cardiac output
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Anesthetic Strategy
 Maximize Fi02
 Eu-volemia (monitor CVP)
 Vent hole in distal femur to decrease pressure
 High pressure lavage to remove debris
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Help create bloodless field
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Goal < 2 hours
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Can cause transient muscle dysfunction
Permanent peripheral nerve damage
Rhabdomyolysis
Lower Extremity
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Can cause pain, metabolic alterations, hemodynamic changes
Increase in blood flow in central circulation
Pain severe enough to require substantial supplementation
despite regional block
Can lead to DVT
Sickle Cell
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Pay attention to maintaining normocarbia, hydration,
normothemria
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Deflation
Fall in CVP, ABP
 Pulse increase
 Temp Decrease
 Increased PaC02,EtC02, lactate and potassium from
ischemic limb
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 Cause increase in Minute Ventilation
 Rare-dysrhythmias
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Re-oxygenation
 Can worsen ischemic injury due to formation of lipid
peroxides
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Fat Embolism Syndrome
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10-20% mortality
Within 72 hours following long-bone or pelvic fx
Triad of dyspnea, confusion and petechiae
 1)Fat globules released by disruption in bone enter
circulation through tears in medullary vessels
 2) or chylomicrons resulting from aggregation of
circulating free fatty acids
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Symptoms
 Coagulation Abnormalities
 Thrombocytopenia, increased clotting time
 Pulmonary
 Range from Mild hypoxia to ARDS
 Under GA
 Decline in ETCO2, arterial oxygen saturation
 Increase in PAP
 ECG-ischemic ST changes and right sided heart strain
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Treatment:
 Prophylactic: early stabilization of fracture
 Supportive: 02, with CPAP, high dose corticosteroid
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Increased risk DVT/PE
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Higher risk
 Obesity, age > 60, procedure > 30 min, tourniquet, LE
fracture and immobilization > 4 days
 Older studies: PE as high as 20% with 1-3% fatal PE
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Anticoagulation as soon as possible
Improvement in occurrence rate
 prophylaxis
 early rehab
 regional anesthesia?
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Neuraxial Anesthesia
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Alone or with general can reduce embolic complications
 Sympathectomy induced increase in LE venous blood flow
 Systemic anti-inflammatory effect of local anesthetic
 Decreased platelet reactivity
 Increase in factor 8,vW
 Decrease in Antithrombin III
 Decrease in stress hormone release
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Contraindicated with full anticoagulation therapy
 Generally not done within 6-8 hour prophylactic heparin
dose or 12-24 hours of LMWH
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Pre-op
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Mostly elderly
Pre-op hypoxia
 Fat emboli, bibasilar atelectasis, pulmonary
congestion/effusion or infection
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General vs. regional
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Lower mortality early post-op period for regional
After 2 months, no difference in mortality
Spinal
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Hypobaric technique allows easier positioning
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Etiology
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Osteoarthritis: repetitive trauma
Rheumatoid Arthritis
 Atlanto-axial instability:
 Preoperative:
 Flexion and extension radiographs of the cervical spine:
 Especially those on immune therapy, steroids methotrexate
 Intubate with fiberoptic/video assist
 Limited jaw mobility
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Intra-op
Lateral Decubitus
 +/ - Arterial Monitoring
 Considerations
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 Bone Cement Implantation Syndrome
 Blood Loss
 Thromboembolism
 Most often during insertion of femoral prosthesis
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Bilateral
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Recommended to monitor PA pressure in case of
emboli
 PAP> 200 during first hip, contralateral should be
postponed
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Revision
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Significant blood loss
 If possible, controlled hypotension
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Knee Arthroscopy
Knee Replacement
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Pre-op considerations
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Usually young/healthy however increasing
frequency in elderly
Intra-op Management
Surgeons favor bloodless field (tourniquet)
 LMA
 Neuraxial vs. alternative regional
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Post-op Pain Control
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Multi-orifice catheter (Painball)
Corticosteroid injection
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Regional: 3 options
 Femoral with or without sciatic block
 Psoas Compartment Block
 Local Infiltration
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Pre-op
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Usually secondary to OA/RA
Intra-op
Blood loss decreased by tourniquet
 Bone cement implantation syndrome less likely then
hip
 Regional technique similar to Arthroscopy
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 Continuous catheter (Epidural vs. femoral)
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Shoulder
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Open or Arthoscopic
Lateral Decubitus or Beach Chair
 Interscalene block preferred
 +/- interscalene catheter
 Side effects:
 Phrenic nerve palsy
 Horner's syndrome
 Mild controlled hypotension requested
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Elbow
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Open or Arthoscopic
 Infra-clavicular block preferred
Head and Upper torso elevated 30-90 degrees
 Complications
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 Stroke, Ischemic Brain Injury and Vegetative State
Decreased cerebral Perfusion
 Each cm of head elevation above heart there is a decrease
in arterial blood pressure of .77
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 20 cm not uncommon
 Approximately 15-16 mm Hg gradient from heart/cuff
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Measure height difference at External Auditory Meatus
 Same level of Circle of Willis
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Avoid in Elderly, HTN
 Compromised autoregulatory curve
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Most common
Posterior spinal fusion
 Scoliosis correction
 Combined antero-posterior procedures
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Anesthetic Considerations
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Neuro-monitoring
 Awareness (+/- BIS)
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Position
 Often prone for long periods of time
 Mayfield tongs or Prone Pillow
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Blood Loss
Cases > 6 hour with > 1 L blood loss highest risk
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Ischemic Optic Neuropathy
 Variation in blood supply
 Orbital Edema
 Increased venous pressure can cause decreased arterial
flow
 Ocular Perfusion Pressure
 Function of MAP and IOP (Intraocular Pressure)
 OPP = MAP – IOP
 Prone position associated with increased IOP
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Central Retinal Artery Occlusion
 Emboli
 Direct pressure on Eyeball
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Visual loss Registry with ASA
Most Healthy/Prone position
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93 total
 83 Ischemic Optic Neuropathy
 10 Central Retinal Artery Occlusion
 55 bilateral
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Mean blood loss 2 L
 Range .1 – 25 L
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Blood loss > 1L and case longer then 6 hour = 96%
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Butterworth IV JF, Mackey DC, Wasnick JD.
Chapter 38. Anesthesia for Orthopedic Surgery. In:
Butterworth IV JF, Mackey DC, Wasnick JD, eds.
Morgan & Mikhail's Clinical Anesthesiology. 5th ed.
New York: McGraw-Hill; 2013.
http://www.accessmedicine.com/content.aspx?aI
D=57236471. Accessed June 12, 2013.
Chelly, Jacques. Peripheral Nerve Blocks: A Color
Atlas. 2009.
Miller, Ronald D. and Manuel C. Pardo. Basics of
Anesthesia , Sixth Edition.Chapter 32 , 499-513
Copyright © 2011,

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