Anesthesia for Orthopedic Surgery
Download
Report
Transcript Anesthesia for Orthopedic Surgery
David Hirsch M.D.
“There is a
fracture, I need to
fix it.”
(http://www.yout
ube.com/watch?v
=3rTsvb2ef5k)
none
Special considerations
Hip Surgery
Knee Surgery
Upper Extremity
Spine Surgery
Peripheral Nerve Blocks
Bone cement (polymethylmethacrylate)
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
Bone Cement Implantation Syndrome
Hypoxia – increased pulmonary shunt
Hypotension
Dysrhythmias- heart block and sinus arrest
Pulmonary hypertension – increased PVR
Decreased cardiac output
Anesthetic Strategy
Maximize Fi02
Eu-volemia (monitor CVP)
Vent hole in distal femur to decrease pressure
High pressure lavage to remove debris
Help create bloodless field
Goal < 2 hours
Can cause transient muscle dysfunction
Permanent peripheral nerve damage
Rhabdomyolysis
Lower Extremity
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
Pay attention to maintaining normocarbia, hydration,
normothemria
Deflation
Fall in CVP, ABP
Pulse increase
Temp Decrease
Increased PaC02,EtC02, lactate and potassium from
ischemic limb
Cause increase in Minute Ventilation
Rare-dysrhythmias
Re-oxygenation
Can worsen ischemic injury due to formation of lipid
peroxides
Fat Embolism Syndrome
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
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
Treatment:
Prophylactic: early stabilization of fracture
Supportive: 02, with CPAP, high dose corticosteroid
Increased risk DVT/PE
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
Anticoagulation as soon as possible
Improvement in occurrence rate
prophylaxis
early rehab
regional anesthesia?
Neuraxial Anesthesia
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
Contraindicated with full anticoagulation therapy
Generally not done within 6-8 hour prophylactic heparin
dose or 12-24 hours of LMWH
Pre-op
Mostly elderly
Pre-op hypoxia
Fat emboli, bibasilar atelectasis, pulmonary
congestion/effusion or infection
General vs. regional
Lower mortality early post-op period for regional
After 2 months, no difference in mortality
Spinal
Hypobaric technique allows easier positioning
Etiology
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
Intra-op
Lateral Decubitus
+/ - Arterial Monitoring
Considerations
Bone Cement Implantation Syndrome
Blood Loss
Thromboembolism
Most often during insertion of femoral prosthesis
Bilateral
Recommended to monitor PA pressure in case of
emboli
PAP> 200 during first hip, contralateral should be
postponed
Revision
Significant blood loss
If possible, controlled hypotension
Knee Arthroscopy
Knee Replacement
Pre-op considerations
Usually young/healthy however increasing
frequency in elderly
Intra-op Management
Surgeons favor bloodless field (tourniquet)
LMA
Neuraxial vs. alternative regional
Post-op Pain Control
Multi-orifice catheter (Painball)
Corticosteroid injection
Regional: 3 options
Femoral with or without sciatic block
Psoas Compartment Block
Local Infiltration
Pre-op
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
Continuous catheter (Epidural vs. femoral)
Shoulder
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
Elbow
Open or Arthoscopic
Infra-clavicular block preferred
Head and Upper torso elevated 30-90 degrees
Complications
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
20 cm not uncommon
Approximately 15-16 mm Hg gradient from heart/cuff
Measure height difference at External Auditory Meatus
Same level of Circle of Willis
Avoid in Elderly, HTN
Compromised autoregulatory curve
Most common
Posterior spinal fusion
Scoliosis correction
Combined antero-posterior procedures
Anesthetic Considerations
Neuro-monitoring
Awareness (+/- BIS)
Position
Often prone for long periods of time
Mayfield tongs or Prone Pillow
Blood Loss
Cases > 6 hour with > 1 L blood loss highest risk
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
Central Retinal Artery Occlusion
Emboli
Direct pressure on Eyeball
Visual loss Registry with ASA
Most Healthy/Prone position
93 total
83 Ischemic Optic Neuropathy
10 Central Retinal Artery Occlusion
55 bilateral
Mean blood loss 2 L
Range .1 – 25 L
Blood loss > 1L and case longer then 6 hour = 96%
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,