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,