1. Anesthesia for Orthopedic surgery
อรุณชัย นรเศรษฐกมล

2. Content General consideration Specific consideration
Age-specific orthopedic conditions
Medical comorbidities
Coexisting medication
Specific consideration
Positioning
Bone cement
Pneumatic tourniquet
Fat embolism
Deep vein thrombosis & Thromboembolism

3. Age-specific orthopedic condition
Young adult
ACL reconstruction, Rotator cuff
Elderly
Hip, Knee arthroplasty
Hip Fracture
Children
Congenital orthopedic surgery

4. Medical comorbidities
Elderly patients
Multiple organ dysfunction
Rheumatoid arthritis
Osteoarthritis
Ankylosing spondylitis

6. Rheumatoid arthritis problem should be aware
Cervical spine instability
IV access
Systemic involvement
Airway management
Spinal or epidural may be difficult
Positioning

7. Osteoarthritis

8. Joint usually involved in Osteoarthritis

10. Osteoarthritis ( OA) problem should be aware
Reduced joint movement
Airway management
IV access
Spinal or epidural may be difficult
Positioning
Concurrent analgesic therapy

11. Ankylosing spondylitis

12. Ankylosing spondylitis

13. Ankylosing spondylitis (AS) problem should be aware
Fix flexion deformity
Regional anesthesia may be difficult
Abnormal spread of local anesthetics

14. Coexisting medication
Antihypertensive drugs
Steroids
Aspirin
NSAIDs
Opioid analgesics
Immunosuppressive drugs

15. Specific consideration

16. Positioning
Supine
Lateral
Prone
Beach chair
Fracture table

17. Why is positioning important?
Enable IV and catheter to remain patent
Enable monitors to function properly
Facilitates the surgeon’s approach
Patient safety

18. Supine

19. Supine Patient on back Arms on arm boards Arm tucked
Arm < 90 degrees
Arm is supinated ( palm up)
Place padding under elbow if able
Arm tucked
Check fingers
Check IV lines and SaO2 probe

20. Lateral

21. Lateral Body alignment Keep neck in neutral position
Always place axillary roll
Place padding between knees
Place padding below lateral aspect of dependent leg

22. Lateral Position arms to parallel to one another
Place padding between arms or place non-dependent arm on padded surface

23. Prone

24. Prone Face down Head placement Head straight forward Head turned
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

25. Prone Arm placement Chest rolls Iliac support
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

26. Fracture table

27. Injury occuring from prolonged positioning
Eye compression in prone position
Skin breakdown due to prolonged positioning

28. Bone cement Polymethylmethacrylate: MMA

29. intramedullary pressure high
Liquid MMA monomer + MMA powder
intramedullary pressure high
medullary content into circulation
(fat, marrow, thrombus, air, bone cement)
Embolization to the lung
unbound MMA monomer
Absorbing into the circution
Vasodilation

30. 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

31. Clinical presentation
Fever
Hypoxia
Hypotension
Tachycardia
Dysrhythmia
Mental status change
Dyspnea
End tidal CO2 decrease
Right ventricular failure and cardiac arrest

32. Management Supportive care Monitoring vital signs O2 supplement
IV fluid
Vasopressor

33. Pneumatic tourniquet No more than 2 hours
100 mmHg above systolic blood pressure
250 mmHg for arm
350 mmHg for leg

34. Pneumatic tourniquet Advantage Disadvantages
Eliminate intraoperative bleeding
Disadvantages
Neurologic effect
Muscle change
Systemic effects of the tourniquet inflation
Syeyemic effects of the tourniquet release

35. 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

36. Muscle changes Cellular hypoxia Cellular acidosis
Endothelial capillary leak
Limb becomes colder

37. Systemic effect of tourniquet inflation
Arterial pressure elevated

38. 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

39. Prevention Select patients Wide, low-pressure cuff
Apply the lowest pressure to prevent bleeding
Limit time to 2 hours
Set maximum pressure
Arm mmHg above systolic
Leg mmHg above systolic
Adequate padding underneath

40. Fat embolism
The mechanical theory
The biochemical theory

41. pulmonary hypertension
Injury of the long bone, pelvis or surgery
that increases intramedullary pressure
Force large fat droplets
into the systemic venous circulation
Embolizing to the right heart and lung
pulmonary hypertension

42. Clinical finding Cardiovascular Respiratory Cerebral Ophthalmic
Persistent tachycardia, hypotension
Respiratory
Dyspnea hypoxia hemoptysis
Cerebral
Delirium stupor seizure coma
Ophthalmic
Retinal hemorrhage
Cutaneous
petechiae
Other
Jaundice fever

43. Treatment Prophylactic Supportive Early stabilization of the fracture
Respiratory care
Maximize O2, ventilation
Invasive monitor
Volume status
Inotrope
High dose corticosteroid

44. Deep vein thrombosis & Thromboembolism lower extremities, pelvis
Major pathophysiological mechanism
Venous stasis
Hypercoagulable state
Endothelial damage

45. Risk Factor Obesity Age > 60 years Procedure > 30 mins
Use of tourniquet
Lower extremities fracture
Immobilization > 4 days

46. Prevention Prophylactic anticoagulant
Low dose heparin
Warfarin
LMWH
Intermittent pneumatic compression
Neuraxial anesthesia reduce thromboembolic complication

47. Major orthopedic procedure
Total hip replacement
Fracture of the hip
Total knee replacement
Spinal surgery

48. Hip surgery Patient Blood loss 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

49. Positioning Mostly lateral decubitus position
Ventilation perfusion mismatch
Neurovascular problem

50. Potentially life-threatening complication
Bone cement implantation syndrome
Intra and postoperative hemorrhage
Venous thromboembolism

51. Important factor of mortality
Very old age
Female>male
Hip fracture
Obesity
Smoking
Malnutrition
Baseline cardiopulmonary function

52. Anesthetic concerns Invasive monitoring Blood loss Positioning
Cement fixation
Deliberate hypotension

53. 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

54. Revision hip arthroplasty
Blood loss
Longer duration
Deliberate hypotension or regional should be used

55. Total knee arthroplasty
Preoperative consideration
Same as THR
Severe rheumatoid arthritis
Osteoarthritis
Obesity
comorbidity

56. Anesthetic management
Thromboembolism
Fat embolism
Cement
Postoperative blood loss
Postoperative pain; more than THR