Anesthesia for Orthopedic Surgery Flashcards
1
Q
anesthetic technique for ortho procedures
A
- multimodal
- neuraxial
- general
2
Q
multimodal analgesia involves…
A
- NSAIDs
- anticonvulsants
- opioids
- peripheral nerve blocks
- other adjuncts
3
Q
preoperative abx
A
- decrease risk of SSI
- cefazolin within 1 hour of incision time
- vancomycin within 2 hours of incision time
4
Q
CMS surgical care improvement project
A
- post op thromboembolism
- glucose management
- core body temperature
5
Q
spine surgery
A
- most open procedures
- minimally invasive techniques for non-complex procedures
- supine or prone positioning
6
Q
patient populations for spine surgery
A
- spinal cord injury
- scoliosis
- degenerative disk disease
7
Q
anesthetic considerations for spine surgery
A
- general anesthesia - need a secure airway, muscle relaxation
- anticoagulants should be d/c if possible
- preop testing –> CBC, plts, coags, CXR, PFTs, ECG, and ECHO (as appropriate)
- evoke potentials may be monitored
- prone position considerations
- difficult intubation (esp if worried about in line stability)
- A LOT of blood loss
- hypotensive
- POVL if prone from venous pooling
8
Q
evoked potentials + anesthetic management
A
- SSEP
- MEP
- or both can also be monitored
- techs will say the volatile anesthetics affect these however research doesn’t support this
- BUT we still do a TIVA usually (LOL); or 0.5 MAC of gas with TIVA
- PRO TIP –> if monitoring MEPs need 2 soft bite blocks between the molars, the patient will bite down and the blocks prevent them from biting on the tube!
9
Q
POVL
A
- occurs with venous pooling of blood in the prone position
- risk factors are surgery longer than 5 hours, anemia, and male gender
10
Q
prone position
A
- alignment and proper padding are IMPORTANT
- head and neck must be aligned
- eyes must be free of pressure
- chest/breast and genitalia free of pressure
- arms padded and positioned –> superman or tucked
- a lot of beds will have a mirror under head so you can see ETT
11
Q
supine (cervical surgery) position considerations
A
- like with ACDF
- shoulder roll to extend neck
- monitor ETT position
- arms tucked with traction
- BP cuff
- IV placement (a lot of times will have 2 PIV with arms tucked)
- maybe art line just depends
12
Q
spinal cord injury
A
- approximately 11,000/year
- half are cervical
- cervical = head injury, thoracic fractures, pulmonary + CV injury
- lumbar = abdominal injuries, long bone fractures
13
Q
SCI anesthetic considerations
A
- neurologic exam
- airway management
- cardiac considerations
- autonomic hyperreflexiaa
- succinylcholine induced hyperkalemia
- temperature control
14
Q
scoliosis
A
- deformity of the spinal column resulting in lateral curvature and rotation of the spine and rib cage involvement
- up to 25% of patients have concomitant neuromuscular disease and congenital abnormalities
- severity determined by Cobb angle
15
Q
Cobb angle
A
- measurement of the degree of side-to-side spinal curvature
- describes the maximum distance from straight a scoliotic curve may be
- Cobb angle > 60 degrees means pulmonary and CV compromise
16
Q
preop anesthetic considerations for scoliosis
A
- pulmonary function studies
- cv considerations
17
Q
periop anesthetic considerations for scoliosis
A
- posterior vs anterior approach
- surgeries T8 and above (cardiac accelerator fibers)
- wake up test may be done - use propofol and remi
- long and bloody
- need to IVs and be prepared to transfuse
- some autologous transfusions, cell saver, and hemodilution are possible solutions
18
Q
scoliosis anesthetic management
A
- hemodynamic monitoring
- vascular access
- respiratory support
- hypothermia
- replacement of blood and fluid losses
19
Q
degenerative spine disease
A
- involvement more common in lumbar and sacral regions
- includes = spinal stenosis, spondylosis, spondylolisthesis
- may occur singly or concomitantly
- neurologic exam is critical in determining disease level
20
Q
degenerative spine disease anesthetic considerations
A
- preop assessment
- patient positioning (anterior vs posterior approach)
- general vs. regional
- spinal cord monitoring (wake up test, SSEP or MEP)
- blood/fluid management
21
Q
potential complications with degenerative spine disease surgeries
A
- VAE - hypotension and precipitous fall of ETCO2, mill wheel murmur may be heard
- visual loss - in prone position; optic neuropathy, retinal artery occlusions, cerebral ischemia
- postop management
22
Q
upper extremity surgery
A
- arthroscopic or open
- procedures include = joint disorders, fractures, joint arthroplasty, entrapment syndromes
- performed with general or regional
- patient position dependent upon procedure
23
Q
brachial plexus
A
- ventral rami of the C5 to T1 nerve roots
- C4 and T2 are often minor or absent alltogether
- nerve roots exit veretebral foramen converging and diverging into trunks, divisions, cords, and finally terminal branches
- supplies sensory and motor innervation to upper extremity (a few exceptions)
24
Q
pneumonic for brachial plexus divisions
A
- Randy - roots
- Travis - trunks
- Drinks - divisions
- Cold - cords
- Beer - branches (terminal branches)
25
Q
shoulder surgery common procedures
A
- subacromial impingement
- rotator cuff tear
- arthroplasty
- clavicle fractures
26
Q
shoulder surgery common positions
A
- lateral
- beach chair
27
Q
lateral position considerations shoulder surgery
A
- patients in lateral position usually have a kidney rest and then traction holding their operative arm up
- head/neck alignment
- padding and position of non-surgical extremities
- be mindful of cerebral perfusion
28
Q
beach chair position considerations shoulder surgery
A
- decreased cerebral perfusion - 2 mmHg difference for every inch in height above where the BP cuff is
- blindness
- stroke
- brain death
29
Q
beach chair positioning BP monitoring
A
- cuff should be placed on upper arm
- arterial pressure monitoring = transducer should be placed at least to patients heart but preferably to brainstem
- gives you an idea of the cerebral perfusion
30
Q
anesthetic considerations for shoulder surgery
A
- regional anesthesia –> interscalene block (ISB); single shot vs catheter placement
- general anesthesia vs MAC
- ETT vs LMA
- depends on patient
31
Q
interscalene block (ISB)
A
- root level block
- the primary brachial plexus block for procedures involving the shoulder and proximal upper arm
- nerve roots C5-C7 are found in the interscalene groove between the anterior and middle scalene muscles
32
Q
ISB indications
A
- shoulder procedures
- proximal humerus
- lateral two-thirds of clavicle
33
Q
ISB landmarks
A
- sternal head of sternocledomastoid
- clavicular head of sternocledomastoid
- upper border of cricoid cartilage
- clavicle
34
Q
ISB landmark technique
A
- needle inserted between anterior and middle scalene muscles
- needle not placed deeper than 2-3 cm in most patients
35
Q
ISB common side effects
A
- stellate ganglion block (aka horner’s syndrome) - ptosis, miosis, and anhydrosis
- diaphragmatic hemiparesis
36
Q
ISB block pearls
A
- C8 and T1 may not be blocked in about 30% of patients
- avoid injecting close to the transverse process
- the vertebral artery enters at C6, increasing risk of intravascular injection
37
Q
common procedures of arm/hand
A
- surgical repair of fractures (humerus, radius, ulnar, hand)
- arthroplasty
- amputation
- ulnar nerve transplantation
- carpal tunnel release
38
Q
surgery of arm/hand positioning
A
- depends on procedures
- beach chair
- lateral
- supine with arm out
39
Q
surgery of arm/hand anesthetic considerations
A
- regional - supraclavicular vs. infraclavicular vs axillary blocks (single shot vs catheter)
- can also do infiltration at site or a bier block
- general anesthesia vs MAC
- ETT vs LMA
- depends on patient… individualize!
40
Q
Supraclavicular block (SCB) pearls
A
- common side effects = stellate ganglion block or diaphragmatic hemiparesis (phrenic nerve block)
- suprascapular nerve often missed
- increased risk of vascular puncture and pneumothorax
41
Q
SCB
A
- performed at level of trunks
- indications are upper extremity below the shoulder surgery
- good choice for elbow and hand surgery
42
Q
SCB landmarks
A
- lateral insertion of SCM in the clavicle
- Clavicle
- patient’s midline
43
Q
SCB landmark technique
A
- semisitting position head turned away
- lower shoulder, flex elbow, forearm on lap, wrist supinated
- lateral border of SCM visible at level where external jugular vein crosses, trace caudally to where SCM meets clavicle
- needle inserted cephalad to later insertion of SCM at a direction parallel to midline
- nerve stimulator set to current 0.8 mA, desired response is muscle twitch of fingers
44
Q
infraclavicular block (IFCB)
A
- cord level block
- alternative to SCB in patients with severe COPD or respiratory insufficiency
- the cords (lateral, posterior, and medial) are labeled by their relation to the axillary artery
45
Q
IFCB pearls
A
- low frequency may be required depending on how much subQ tissue
- subQ injection of LA may be warranted
- sliding needle medially increases potential for pneumo or hemothorax
- thoraco-acromial artery and pectoral veins pass between the pectoral muscles, doppler may be used to help ID these to prevent inadvertent puncture
46
Q
IFCB indications
A
- block of arm below the shoulder
- hand
- elbow
- forearm
- av fistula
47
Q
IFCB anatomy
A
- three cords surround the axillary artery
- lateral cord is most superficial
- posterior is next
- medial cord is deepest and below the axillary artery
- lateral and medial each contain half of the median nerve
- posterior cord contains all of the radial nerve
- musculocutaneous nerve often outside, but close to lateral cord
48
Q
IFCB landmarks
A
- clavicle
- jugular fossa or notch
- arcomioclavicular joint
- coracoid proccess
49
Q
IFCB landmark technique
A
- semisitting head turned away
- subclavian artery palpated where it crosses clavicle or midpoint of clavicle marked
- brachial artery palpated and marked at lateral border of pectoralis muscle
- line joining these points is made
- insert needle 2.5-3 cm below midpoint of clavicle at 45-65 degree angle towards axillary artery
50
Q
axillary block
A
- axillary block is directed at the terminal branches of the brachial plexus
- excellent block for procedures below the elbow
- US has made it less attractive
51
Q
axillary block anatomy
A
- in apex of axilla, the three plexus cords form the main terminal nerves of the upper extremity
- axillary and musculocutaneous nerves leave the plexus at the level of the coracoid process
52
Q
axillary block landmarks
A
- pulse of axillary artery
- coracobrachialis muscle
- pectoralis major muscle
- biceps muscle
- triceps muscle
53
Q
axillary block landmark technique
A
- arm abducted 90 degrees, elbow flexed
- arterial pulse palpated at level of major pectoralis muscle
- nerve stimulator to 0.5-1 mA
- needle inserted above arterial pulse towards median nerve or below arterial pulse toward radial nerve depending on surgical site
- as superficial fascia penetrated, click felt and current amplitude increased at 1 mA increments until desired twitch (flexion or extension of wrist and fingers)
- needle advanced toward stimulated nerve while reducing amplitude
- once stimulation obtained at current of 0.3-0.5 mA inject local
54
Q
axillary block pearls
A
- perform pre-procedure scan to ID course of each terminal branch
- find axis where all nerves can be blocked with a single needle insertion
- the intercostobrachial nerve (T2) supplies cutaneous innervation of the medial UE
55
Q
lower extremity surgery
A
- may be athroscopic or open
- common procedures = athroplasty, fractures, cartilage and ligament repair
- performed with general or regional
- patient position dependent upon procedure
56
Q
lumbar plexus
A
- arises from ventral rami of L1 - L4 (occassionally T12)
- major nerves = femoral nerve, obturator nerve, lateral femoral cutaneous nerve
- other nerves = ilioinguinal nerve, iliohypogastric nerve
57
Q
lumbosacral plexus
A
- arises from L4/5 - S1/5
- major nerve = sciatic nerve
58
Q
hip surgery
A
- 200,000 replacements annually
- elective vs traumatic
- most are frail and elderly (>65 yo) –> additional comorbidities, mortality 10% in hospital, 25% w/in first year
- blood loss greater with extracapsular (femoral neck, intertrochanteric, subtrochanteric)
- patients positioned lateral or supine
59
Q
lateral positioning for hip surgery
A
- head/neck alignment
- adequate padding of dependent extremities
- prevention of non-operative extremity nerve injury
60
Q
supine positioning for hip surgery
A
- IV just be aware of what position is and if you will have access to the arms
- protection of genitalia
- traction injury to lower extremities
61
Q
hip surgery anesthetic considerations
A
- technique varies based on - elective vs traumatic vs revision, patient population, surgeon
- potential complications = fat embolus, VTE, blood loss
62
Q
hip surgery anesthetic technique regional over general
A
- less post op cognitive dysfunction
- superior post op analgesia
- decreased incidence of DVT and PE
- rapid post-op rehab
- reduced cost of medical care
- neuraxial and peripheral nerve blocks have been used effectively for management
63
Q
regional techniques for hip surgery
A
- can be used for primary anesthetic and post-op analgesia
- neuraxial - spinal vs. epidural
- peripheral nerve blocks - lumbar plexus block (psoas compartment block), single vs continuous, fascia iliaca block
64
Q
knee surgeries
A
- more than 300,000 performed annually
- patients most often elderly with comorbidities
- regional preferred over general
- complete anesthesia requires both lumbar and lumbosacral blocks
- procedures associated with SIGNIFICANT post op pain
65
Q
knee arthroplasty anesthetic considerations
A
- effective post-op pain management is paramount for recovery
- opioids and neuraxial techniques both have limitations
- ERAS protocols - multimodal pain management, continuous peripheral nerve block
66
Q
knee arthroplasty
A
- relatively minor surgery, performed as outpatient
- patient population will influence anesthetic technique and management
- peripheral nerve block rarely indicated
67
Q
ACL repair
A
- more involved than knee arthroplasty but still frequently done outpatient
- may warrant a continuous peripheral nerve block
- knee bolster allows lower extremity to hang freely opening joint space
- non-operative leg support needed to reduce lower back stress
68
Q
Femoral nerve block (FNB)
A
- targets major branches of lumbar plexus
- largest branch of lumbar plexus
- formed by dorsal divisions of anterior rami of L2, L3 and L4 spinal nerves
- emerges from lateral border of psoas muscle and remains deep to fascia iliaca
- provides anesthesia to anterior thigh, knee, and medial aspect of lower leg
- nerve is lateral to artery and deep to fascia lata and iliaca, superior to the iliopsoas muscle
69
Q
FNB landmark
A
- patient supine, leg abducted 10-20 degrees and externally rotated
- site of insertion -femoral crease below inguinal crease and immediately lateral (1cm) to femoral artery
- nerve stimulator - current 1 mA needle introduced at 30-45 degree angle in cephalad direction, advance needle through fascia lata and iliaca (feel pop) as quads muscle contractions are obtained, current decreased while needle advanced
- adequate position of needle = patellar twitches elecited at current 0.3-0.5 mA
- inject 15-20 mL LA
70
Q
FNB pearls
A
- if two arteries seen, scan cephalad and ID single femoral artery
- doppler used to ID presence or absence of vessels
- experience suggests that if the needle and LA are placed below the fascia iliaca and lateral to artery, successful blocks occur despite lack of twitches
- complications avoided by using US
- caution because lymph nodes can appear as nerves (lymph nodes are not continous while nerves are)
71
Q
fascia iliaca block nerve targets
A
- femoral n
- obturator nerve
- lateral femoral cutaneous nerve
72
Q
adductor canal block (ACB)
A
- FNB considered gold standard for pain relief post knee arthroplasty, but risk of falls associated with quadriceps muscle weakness
- ACB provides sensory nerve blockade with minimal motor involvement!
73
Q
ACB pearls
A
- nerve branches may be located on both sides of the superficial femoral artery, pre-procedure scan will detect any aberrancy and increase block efficacy
- mytotoxicity if LA is deposited in muscle
- vastus medialis is consistently blocked too, and may provide greater innervation to knee than previously thought
74
Q
surgery to ankle/foot
A
- innervation to ankle/foot supplied by femoral and sciatic nerves
- elective vs traumatic
- either neuraxial or PNBs are appropriate in combination with general or MAC
- position depends on procedure
75
Q
saphenous nerve block (thigh)
A
- saphenous nerve is terminal branch of the femoral nerve
- distal to the adductor canal the saphenous courses superficially in the distal thigh
- provides only sensory innervation to medial aspect of lower extremity below the knee
- used in conjunction with other blocks for surgery involving ankle and foot
76
Q
lumosacral plexus
A
-provides sensory and motor innervation to posterior thigh, knee, and lower extremity below the knee with exception to sensory innervation provided by saphenous nerve
77
Q
popliteal nerve block
A
- targets sciatic nerve slightly proximal to knee
- provides anesthesia for procedures involving foot and ankle
- in popliteal fossa, nerves are bordered superiorly and medially by the semi-tendinosus and semi-membranous muscles and superiorly and laterally by biceps femoris muscles
78
Q
five nerves that supply innervation to foot
A
- tibial
- deep peroneal
- superficial peroneal
- saphenous
- sural
79
Q
pneumatic tourniquet
A
- often used to minimize blood loss and provide bloodless surgical field
- proper sizing and inflation critical for safe/effective use
- pressure of inflation depends on patient BP and extremity
- should not be used longer than 2 hours
- interrupted blood supply leads to tissue hypoxia and acidosis
- deflation of cuff - release of metabolic waste
- tourniquet pain - occurs at 60 min (pain, HTN)
- known complications
80
Q
polymethylmethacrylate
A
- acrylic bone cement used in arthroplasty
- exothermic reaction that results in expansion and hardening of polymer
- common in elderly patients
- placement of cement associated with sudden hypotension causing BCIS
81
Q
BCIS
A
- Bone Cement Implantation Syndrome
- absorption results in - decreased SVR, hypotension, hypoxemia
82
Q
BCIS risk factors
A
- pre-existing CV disease or pulm HTN
- ASA class 3 or higher
- pathologic fracture, intertrochanteric fracture or long-stem arthoplasty
83
Q
BCIS treatment
A
- D/C nitrous during cementation
- maximize FiO2
- euvolemia
- create vent hole in distal femur
- high pressure lavage
84
Q
Fat embolism syndrome (FES)
A
- associated with traumatic injury and surgery to long bones
- incidence = 3-4%
- occurs when fat enters the blood stream from the broken bone
85
Q
risk factors for FES
A
- age 20-30
- male
- hypovolemic shock
- bilateral total knee
- RA
- intramedullary instrumentation
86
Q
major S/S FES
A
- petechia
- hypoxemia
- CNS depression
- pulmonary edema
87
Q
minor S/S FES
A
- tachycardia
- hyperthermia
- retinal fat emboli
- urinary fat globules
- decreased plts/Hct
- increased sed rate
- fat globules in sputum
88
Q
FES treatment
A
- early recognitioin
- reverse contributing factors
- stabilization of fractures
- aggressive pulmonary support
- pharmacologic therapy
89
Q
DVT/PE
A
- major cause of death following lower extremity trauma or surgery
- without prophylaxis, DVT develops in 40-80% of patients
- PE in up to 28%
90
Q
risk factors for DVT/PE
A
- s/p hip fracture
- advanced age
- immobility
- previous DVT
- cancer
- pre-existing hypercoagulable state
91
Q
complications of arthoscopy
A
- SubQ emphysema
- pneumomediastinum
- tension pneumo
- irrigation 3-5 L irrigating solution bags - make sure to compare fluid in/out; large volumes can lead to volume overload, CHF, pulmonary edema or hyponatremia
