1. Current Issues in the Anesthetic Treatment of the Patient for Orthopedic Sugery
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마취통증의학과
R4 김영순

2. 1. Peripheral Nerve Blocks
Resurgence in the popularity of regional anesthesia techniques
Perioperative pain relief
Current issues in regional anesthesia
Choice of technique (PNS vs. paresthesia)
Appropriate mA and nerve response to accept
Superficial stimulation
Choice for procedure below the elbow
Choice for postOP pain relief
Blocks in anesthetized patients

3. 1. Peripheral Nerve Blocks
PNS is preffered
Clear endpoint
High success rate
Ability to minimize paresthesia
Long history of minimal significant complications
Success with a PNS
Knowledge of anatomy
Initial stimulating current 1 to 1.5 mA : not painful
“Fine-tune mode”
When a twitch is obtained, decrease stimulating current
Injection of local anesthetic
When the best twitch is obtained at the lowest mA possible (0.2 to 0.3 mA)
2 mL injection after negative aspiration
Loss of twitch confirms proximity of the needle to the nerves
The remainder is injected with intermittent aspiration
Another method : use of ultrasound
Less current to stimulate the motor(A-α) fibers of a mixed motor and sensory nerve than the sensory or pain fibers (A-δ or C fibers

4. 1. Peripheral Nerve Blocks
Controversy about the proper mA
In early days, 0.5 to 1.0 mA as endpoint
Decreased to 0.2 to 0.3 mA
With the use of insulated needles and close attention to success rate
Concerns about impaling the nerve
Block should not be performed with the Pt. asleep
Unusual resistance or significant pain on injection
No strong evidence that 0.2 mA is associated with the needle being intraneural
Choyce et al.
Blocks should not performed in adult patients during general anesthesia
Intraneural injection
Injection of the cervial spinal cord
Choyce et al.

5. 1. Peripheral Nerve Blocks
Superficial stimulation
Locating nerves superficially on skin with a PNS
Entry point is determined before a needle stick
The number of needle sticks is decreased
The anesthesiologist looks more adept
Metal component of an ECG electrode
Example ; Brachial plexus
In the axilla
ECG electrode is connected to the nerve stimulator with the current at approximately 5 mA
Twitches of the brachial plexus are sought as proximal in the axilla
Area is marked and becomes the needle entry location site for performing the block

6. 1. Peripheral Nerve Blocks
Based on the site of surgery
Interscalene block
Shoulder down to the midshaft of the humerus
Infraclavicular nerve block
Elbow, forearm, and hand
Axillary block
Ulnar side of the hand .
Infraclavicular block
Fig. 1 Diagram of the infraclavicular block

7. 1. Peripheral Nerve Blocks
Infraclavicular block (Fig. 1)
Instead of palpating for the axillary artery, superficial stimulation can be used to locate the brachial plexus as proximal in the axilla as possible
Advantage at this level
Musculocutaneous nerve is still part of the brachial plexus
No need for a separate block of the musculocutaneous nerve in the coracobrachialis muscle
Biceps twitch is not a reliable endpoint
Twitches in the hand or forearm should be used as the endpoint
Generated from the median, ulnar, or radial nerve

8. 1. Peripheral Nerve Blocks
Lumbar plexus block
For lower extremity surgery
In the distribution of the femoral, obturator, and lateral femoral cutaneous nerves
Fractured hip repair, femoral shaft surgery, and other anterior femur surgery
Femoral and lateral femoral cutaneous nerve block
Femoral neck fractures necessitating cannulated pinning
Combined femoral and sciatic nerve block
Effective for procedures on the knee or distal to the knee
Femoral nerve block or fascia iliaca block
Postoperative pain relief after knee surgery

9. 1. Peripheral Nerve Blocks
Fascia iliaca block (Fig. 2)
does not use the nerve stimulator technique
Between the femoral nerve and the lateral femoral cutaneous nerve
Fig.2. Diagram of the fascia iliaca block
Fascia iliaca block

10. 2. Spine Surgery Current issues
Understanding the degree of cervical spine pathology
Caring for patients undergoing prolonged surgical procedure
Use of lung isolation technique
Loss of vision
The effect of NSAIDs on bone healing

11. Difficulty intubating patients with RA
2. Spine Surgery
Difficulty intubating patients with RA
Temporomandibular joint arthritis
Hypoplastic mandible
Overbite
Effects of RA on the cervical spine
Atlantoaxial subluxation
Subaxial subluxation
Superior migration of the odontoid
Ankylosing spondylitis
Fused cervical spines fixed in a flexed position
Forced movement ; cervical cord damage
The head must be supported
Breathing in a rapid shallow pattern
Atlantoaxial subluxation
Subaxial subluxation
Superior migration of the odontoid

12. Organized approach to the Pts. with cervical spine disease
2. Spine Surgery
Organized approach to the Pts. with cervical spine disease
Proper preOP evaluation
Range of motion
Review of x-rays in flexion and extension
Appropriate use of intubation aides; flexible bronchoscope
Major spine surgery
Anterior procedure
Thoracic exposure, lung isolation
Taking many hours
Major blood loss and fluid shifts
Perioperative considerations
Controlling blood pressure
Monitoring spinal cord function
Treating blood loss
Positioning concerns

13. Lung isolation technique
2. Spine Surgery
Lung isolation technique
Double-lumen tube or bronchial blocker
Univent tube® (Fig.3)
Advantage
Does not have to change the endotracheal tube between ant. and post. portions of the surgery
Can be left in place if controlled ventilation is necessary in the postoperative period
Drawback
External diameter is large
Fig.3 Diagram of technique using a double-lumen tube with bronchial blocker for lung isolation in open thoracic or thoracic procedures.

14. Postoperative vision loss
2. Spine Surgery
Prone position
Alteration in pulmonary function
Increases in venous pressure
Pressure and stretch on nerves
Visual loss
Postoperative vision loss
Combination of factors
Perioperative anemia
Hypotension
Prolonged surgery
Resistance to blood flow
Direct pressure on the eye
not seem to be the cause of the majority of cases of visual loss

15. Ischemic optic neuropathy
2. Spine Surgery
Ischemic optic neuropathy
Common diagnosis in postOP visual loss
Decreases in ocular perfusion pressure(OPP)
Decreased blood supply to the optic nerve
Posterior ciliary arteries ; end arteries
Placing the area at risk for ischemia as OPP is decreased
OPP = MAP – IOP
Decreases in MAP or increases in IOP decrease OPP
Prone position, especially in a slight head-down tilt
Edema and venous engorgement
Increasing IOP
Etiology of vision loss is unclear

16. IntraOP monitoring of spinal cord function
2. Spine Surgery
Nonspecific NSAIDs
Ketorolac ; interfere with bone fusion after spine surgery
Avoid using ketorolac in this setting
Specific cyclooxygenase 2 inhibitors
Recommendation for use ; necessitate further clarification
IntraOP monitoring of spinal cord function
Somatosensory evoked potentials
Nitrous oxide-oxygen, opioid technique with an infusion of propofol and muscle relaxant
Benzodiazepine ; avoided
Motor evoked potentials
Electromyograms
Assess pedicle screw placement
Muscle relaxants must be discontinued early enough
Wake-up test
Remember secure the endotracheal tube

17. Considerations before deciding to extubate the patient
2. Spine Surgery
Considerations before deciding to extubate the patient
Combined anterior-posterior spine procedures
Can be prolonged
Degree of swelling ; important
Significant facial swelling
indication to leave the endotracheal tube in place
Additional improtant factors
Hematocrit
Body temperature
Pulmonary function
Reversal of neuromuscular blockade

18. 3. Anticoagulation and Orthopedic Patients
Major concerns
High incidence of deep vein thrombosis
Associated risk of fatal pulmonary embolus
Attempt to decrease the incidence
Anesthesiologist; neuraxial anesthetic
Surgeon; periOP thromboprophylaxis
Warfarin or Dextran®
LMWH and other antithrombotic agents
e.g., Fondaparinux, an anti-Xa medication

19. Spinal hematoma 3. Anticoagulation and Orthopedic Patients
US FDA to issue a warning
Anticoagulants or antiplatelet medication in addition to LMWH
Epidural catheter removed at a time of therapeutic anticoagulation by the LMWH
Occurred muck less freauently in Europe
Dosing interval, Dosage, Level of attention
More subtle onset of neurologic changes
Not the excruciating back pain
Other anticoagulants or antiplatelet medications
Should be avoided when LMWH is used
Appropriate timing
Neuraxial anesthesia 10 to 12 hours after last dose of LMWH
First dose of LMWH in the postOP period
Clopidogrel
Potent antiplatelet medication
A week before performing spinal anesthesia

20. The End