Anesthesia for Orthopedics (Part 3) Flashcards
What is arthroscopy?
Minimally invasive surgery performed to examine and sometimes repair damage to the interior of a joint
-Can use any type of anesthesia, pt dependent
Pt positioning for arthroscopy
Lower extremity: supine
Hip: lateral or supine
Shoulder: modified fowler (beach) or lateral
Arthroscopy uses fluid instilled under pressure for visualization. This can cause what?
Fluid overload, CHF, pulmonary edema, hyponatremia, hypothermia
For each CM of head elevation above the heart we see a ___mmHg reduction in MAP
0.75 mmHg per cm
2 mmHg per inch
The ___-____ reflex can cause issues in shoulder surgery with an interscalene block in the sitting position.
Bezold-Jarisch
The Bezold-Jarisch reflex effects are seen as profound ____ and ____.
Hypotension and bradycardia
What is arthroplasty?
Surgical replacement of a joint to restore motion and function
Nearly ___% of hip arthroplasty patients are also obese.
50%
-This adds a whole new level of complication by bringing in all anesthesia obesity considerations.
The ____ approach is most common for THA.
Posterior approach - involves incision from iliac crest across joint to midthigh (lateral position)
-A direct anterior approach is growing as it is available as minimally invasive (supine)
The THA anesthetic plan usually includes ____ anesthesia unless contraindicated.
Regional
The use of ____ ____ inhibits fibrinolysis and is used in THA to cut down blood loss.
Transexamic acid (TXA) 1-2g
TKA are commonly done with the ___ ___ block and in what position?
Usually GA with adductor canal block in the supine position
____ ____ is used for assisting in blood loss.
Transexamic acid (TXA) 1-2g
-Also the pneumatic tourniquet around the thigh
Anesthesia options for ankle arthroplasty?
- Tourniquet and spinal/epidural
- Combination of regional techniques for intra and postop
- Sciatic and femoral blocks - work for all below knee
Some big issues with shoulder arthroplasty?
Cerebral ischemia
POVL
Bezold-Jarisch (sitting position, interscalene block)
When surgery is performed in the sitting position, what are some things we need to take into account?
Lower venous return = lower BP
Can lead to cerebral ischemia and POVL (ION - Ischemic Optic Neuropathy)
Civilian extremity injuries occur most often due to ___.
Falls (43%)
MVC second with 26%
The highest risk of massive hemorrhage is with ___ fx.
Pelvic fx
-Risk of shock, fat emboli, thromboembolic hypoxic respiratory failure
Ideal time for open fx repair is _____. It should be done with what type of anesthesia for greatest pt safety?
Within 12 hours. Done under GA for aspiration risk - possible full stomachs
Mortality rates climb up to ___% with open pelvic fractures.
70%
-Huge risk for massive hemorrhage, remember TXA for these pts!
Main role of the anesthetist in pelvic fx repair?
The anesthetist’s role at this time should focus on close monitoring of hemodynamic end-organ perfusion in addition to replacing blood loss using principles of damage control resuscitation.
Blood Supply for spine includes:
__ Anterior Spinal Arterie(s)
__ Posterior Spinal Arterie(s)
-1 Anterior Spinal Artery: the Artery of Adamkiewicz @T10-11 –> disruption = paralysis
-2 Posterior Spinal Arteries
Anesthetic challenges for spinal surgery:
-Airway management
-Fluid and blood management
-Hemodynamic control and monitoring
-Perioperative anaglesia
Gold standard surgical approach for spinal stenosis
Bony decompression by laminectomy
-Can be alongside lumbar interbody fusion for stability
For anterior spinal surgical approaches on thoracic segments, we will need what?
A double-lumen ETT for one lung ventilation
What will be much harder to do successfully in spinal fusion patients?
Subarachnoid blocks and epidurals at the level of the fusion
What surgical technique is used for scoliosis
Anterior, posterior, or combo
-Anterior requires thoracotomy and double ETT
What is important for us as anesthesia in scoliosis surgery or any serious spinal surgery?
-Good IV access
-Advanced BP monitoring
-Access to blood products
-Purposeful use of hypotensive technique
Why is a laparoscopic approach advantageous in the anterior approach?
-Better respiratory functioning
-Diminished blood loss
-Shorter LOS
-Lower costs
**Only appropriate for the right patients
What patients should NOT be a candidate for laparoscopic spinal surgery?
- Previous abdominal surgery/trauma
- Thoracic spine surgery that CANNOT tolerate one lung anesthesia
- Internal fixation with extensive instrumentation
Spinal Surgery Anesthesia Management (putting it all together here)
-Good IV access
-Advanced monitoring (ABP, SSEP, MEPs)
-Proper positioning
-Airway A/B/C
-Can pt tolerate one lung anesthesia if that is the plan?
-Hypotensive technique
-Blood conservation strategies
What are some examples of blood conservation strategies?
-Predonation autologous blood
-Cell saver
-Surgical site infiltration with epi
-Hypotensive anesthesia
-TXA
What changes on EP can signify possible cerebral ischemia?
50% reduction in amplitude
OR
10% increase in latency
SSEPs monitor what? Can we use NMB with SSEP?
Monitor the integrity of the neural structures along both the peripheral and central somatosensory pathways
-We CAN use NMB
Anesthesia effects on SSEPs
Increase latency and decrease amplitude
Ketamine, etomidate, opioids the exception
Use narc-based, TIVA, 1/2 MAC
Avoid N2O - depressant
____ and ____ increase cortical amplitudes and enhance SSEP/MEP waveforms.
Ketamine and etomidate
MEPs monitor what? Can we use NMB?
Monitor integrity of motor tracts (anterolateral spinal cord/corticospinal tract)
-CANNOT use NMB
Anesthesia effects on MEPs
Narc-based, TIVA, 1/2 MAC
Avoid N2O - depressant
NO NMBA
What does an electromyography do?
Can we use NMB?
Stimulates a motor nerve and monitors known innervated muscle groups
NO NMB
Difference in EMG versus SSEP/MEP?
EMG cannot monitor for ischemia
A NIMS ETT allows for what?
Monitoring of the vocal cords
Used in ACDF surgery
Prone positioining changes
-Decreased CO and BP unless torso in plane
-Keep abdomen free floating
-Decreased FRC and TLC
-Increased abdominal pressures, PIP
-Use pressure control ventilation
Wilson Frame table allows for what that may increase comfort and outcomes?
Natural curvature of spine is supported
The huge MUST for the rotisserie table
Ensure the top of the sandwich is secure!!
Chickens and sandwiches.. idk
In a face down position we should check positioning of face how frequently?
q15-30 mins
-Use mirror, maintain patent tube
Orthopedic extremity surgery uses ___ ___.
Pneumatic tourniquet
There are roughly _____ spinal cord injuries per year in the US.
10,000 with about 80% males
Spinal cord outcomes are dependent on what 3 factors?
- Severity of acute injury
- Prevention of exacerbation of injury during rescue, transport, and hospitalization
- Avoidance of hypoxia and hypotension
T/F: >50% of all traumatic spinal cord injuries occur in cervical region.
TRUE.
Most common SCI types:
- Incomplete tetraplegia (31%)
- Complete paraplegia (25%)
- Complete tetraplegia (20%)
- Incomplete paraplegia (19%)
Tetraplegia results in:
Partial or total loss of all four limbs and the torso
Paraplegia results in:
Only lower extremities and torso affected
6 p’s of SCIs:
- Pain
- Paralysis
- Paresthesia
- Priapism
- Ptosis
- Position
SCI pts should have spinal immobilization before being moved. What position will we obtain an airway in?
Manual in-line stabilized position
Radiologic evaluation should include which cervical vertabrae?
All 7
C7 most commonly injured site
An SCI above C-3 often results in what?
Apnea, rendered ventilator dependent
_____ could exacerbate a SCI due to fasciculations.
Succ
We will maintain a MAP of ~___mmHg for best patient perfusion in spinal cord injuries
~90 mmHg
What induction agents should be used on spinal cord injury patients: Propofol or ketamine?
Hemodynamically stable = Propofol
Unstable = Ketamine, but expect increased ICP
3 main symptoms of spinal shock:
- Hypotension
- Bradycardia
- Hypothermia
A turned of sympathetic system is the best way to think of these
-Worse as we move more cephalad above T6
What is autonomic dysreflexia?
Sudden activation of sympathetic response secondary to a noxious stimuli
-Presents with extreme HTN
-Possible seizure, pulm edema, MI, AKI, intracranial hemorrhage
Management of autonomic dysreflexia:
Determine the noxious stimuli and correct it
Fix BP
Thats all she wrote. Enjoy the studying!
Spring break next week yee haw
