Transcript Anesthesia for Orthopedic surgery
Anesthesia for Orthopedic surgery
อรุณชัย นรเศรษฐกมล
Content
General consideration
Age-specific orthopedic conditions
Medical comorbidities Coexisting medication
Specific consideration
Positioning
Bone cement Pneumatic tourniquet
Fat embolism Deep vein thrombosis & Thromboembolism
Age-specific orthopedic condition Young adult ACL reconstruction, Rotator cuff Elderly Hip, Knee arthroplasty Hip Fracture Children Congenital orthopedic surgery
Medical comorbidities Elderly patients Multiple organ dysfunction Rheumatoid arthritis Osteoarthritis Ankylosing spondylitis
Rheumatoid arthritis problem should be aware Cervical spine instability IV access Systemic involvement Airway management Spinal or epidural may be difficult Positioning
Osteoarthritis
Joint usually involved in Osteoarthritis
Osteoarthritis ( OA) problem should be aware Reduced joint movement Airway management IV access Spinal or epidural may be difficult Positioning Concurrent analgesic therapy
Ankylosing spondylitis (AS) problem should be aware Fix flexion deformity Regional anesthesia may be difficult Abnormal spread of local anesthetics
Coexisting medication Antihypertensive drugs Steroids Aspirin NSAIDs Opioid analgesics Immunosuppressive drugs
Specific consideration
Positioning Supine Lateral Prone Beach chair Fracture table
Why is positioning important?
Enable IV and catheter to remain patent Enable monitors to function properly Facilitates the surgeon’s approach Patient safety
Supine Patient on back Arms on arm boards Arm < 90 degrees Arm is supinated ( palm up) Place padding under elbow if able Arm tucked Check fingers Check IV lines and SaO2 probe
Lateral Body alignment Keep neck in neutral position Always place axillary roll Place padding between knees Place padding below lateral aspect of dependent leg
Lateral Position arms to parallel to one another Place padding between arms or place non-dependent arm on padded surface
Prone Face down Head placement Head straight forward ET tube placement and patency Check bilateral eyes/ears for pressure points Head turned Check dependent eye/ear, ETT placement Be aware of potential vascular occlusion
Prone Arm placement Tucked – similar to supine Abducted Check neck rotation and arm extension to avoid brachial plexus injury Elbow are padded Chest rolls Iliac support Padding in placed under iliac crests
Injury occuring from prolonged positioning Eye compression in prone position Skin breakdown due to prolonged positioning
Bone cement Polymethylmethacrylate: MMA
Bone cement implantation syndrome ( BCIS) Release of vasoactive and myocardial depressant substances Intravascular thrombin generation in the lungs Direct vasoactive effects of absorbed MMA Acute pulmonary microembolization
Clinical presentation Fever Hypoxia Hypotension Tachycardia Dysrhythmia Mental status change Dyspnea End tidal CO2 decrease Right ventricular failure and cardiac arrest
Management Supportive care Monitoring vital signs O2 supplement IV fluid Vasopressor
Pneumatic tourniquet No more than 2 hours 100 mmHg above systolic blood pressure 250 mmHg for arm 350 mmHg for leg
Pneumatic tourniquet Advantage Eliminate intraoperative bleeding Disadvantages Neurologic effect Muscle change Systemic effects of the tourniquet inflation Syeyemic effects of the tourniquet release
Neurologic effects Tourniquet pain and hypertension If > 45-60 mins Neurapraxia if > 2 hours Nerve injury at the skin level the edge of the tourniquet
Muscle changes Cellular hypoxia Cellular acidosis Endothelial capillary leak Limb becomes colder
Systemic effect of tourniquet inflation Arterial pressure elevated
Systemic effect of tourniquet release Transient fall in core temperature Transient metabolic acidosis Release of acid metabolites into central circulation Transient fall in arterial pressure Transient increase in EtCO2
Prevention Select patients Wide, low-pressure cuff Apply the lowest pressure to prevent bleeding Limit time to 2 hours Set maximum pressure Arm 50-75 mmHg above systolic Leg 75-100 mmHg above systolic Adequate padding underneath
Fat embolism The mechanical theory The biochemical theory
Clinical finding Cardiovascular Persistent tachycardia, hypotension Respiratory Dyspnea hypoxia hemoptysis Cerebral Delirium stupor seizure coma Ophthalmic Retinal hemorrhage Cutaneous petechiae Other Jaundice fever
Treatment Prophylactic Early stabilization of the fracture Supportive Respiratory care Maximize O2, ventilation Invasive monitor Volume status Inotrope High dose corticosteroid
Deep vein thrombosis & Thromboembolism
lower extremities, pelvis Major pathophysiological mechanism Venous stasis Hypercoagulable state Endothelial damage
Risk Factor Obesity Age > 60 years Procedure > 30 mins Use of tourniquet Lower extremities fracture Immobilization > 4 days
Prevention Prophylactic anticoagulant Low dose heparin Warfarin LMWH Intermittent pneumatic compression Neuraxial anesthesia reduce thromboembolic complication
Major orthopedic procedure Total hip replacement Fracture of the hip Total knee replacement Spinal surgery
Hip surgery Patient Limit ability to exercise Cardiovascular function can be difficult to assess Elderly with systemic disease, OA,RA Blood loss Use of hypotensive technique or reginal anesthesia reduces blood loss
Positioning Mostly lateral decubitus position Ventilation perfusion mismatch Neurovascular problem
Potentially life-threatening complication Bone cement implantation syndrome Intra and postoperative hemorrhage Venous thromboembolism
Important factor of mortality Very old age Female>male Hip fracture Obesity Smoking Malnutrition Baseline cardiopulmonary function
Anesthetic concerns Invasive monitoring Blood loss Positioning Cement fixation Deliberate hypotension
GA or RA GA Decrease lung function Depress cough Increase secretion Depress cardiac function RA Reduce lung complication Reduce thromboemboli Reduce delirium Reduce blood loss
Revision hip arthroplasty Blood loss Longer duration Deliberate hypotension or regional should be used
Total knee arthroplasty Preoperative consideration Same as THR Severe rheumatoid arthritis Osteoarthritis Obesity comorbidity
Anesthetic management Thromboembolism Fat embolism Cement Postoperative blood loss Postoperative pain; more than THR