Week 4 Considerations for Ortho Surgery Flashcards
What are 3 components of preop teaching for orthopedic patients?
- procedure review
- anesthetic/analgesic options
- review of rehabilitation plan
Why is preop teaching so important for ortho patients?
*get the patient motivated to get home / go home.
What is included in a preop evaluation for ortho patients?
7
– PMHx (previous surgeries, review of medications, anticoagulant status) – Focused physical examination – Laboratory values – Diagnostic studies
What lab is extremely important to get preop for spine patients?
type/screen & CBC
*check if patient takes blood thinners
What 4 labs are important to check in a total joint replacement?
- CBC
- pregnancy
- urinalysis
- type & screen
What is a major complication of total joint replacement?
surgical site infection
- make sure antibiotics are given at the appropriate time
When should ancef be administered?
Should be IN within 1 hour of incision
When should vancomycin be administered?
Should be IN within 2 hours of incision
What could be included in a multimodal analgesia plan for ortho patients? (5)
- NSAIDS
- Anticonvulsants (gabapentin)
- opioids
- peripheral nerve block
- other adjuncts
What are advantages of outpatient/arthroscopic surgery for ortho patients?
- faster recovery
- shorter LOS
- fewer narcotics
- faster return to work
What 2 services could perform spine surgery?
- ortho
2. neurosurgery
Spines are what type of procedure?
open, could be anterior or posterior
What are 3 patient populations that may need spine surgery?
- spinal cord injury
- scoliosis
- degenerative disk disease
How might scoliosis affect normal physiology?
- restrictive lung dz
2. hemodynamic changes d/t limited thoracic space
What kind of anesthetic is used during spine surgery?
TIVA; precedex, remifentanil
- no more than 0.5 MAC if SSEPs are being monitored
What may be monitored during spine surgery?
SSEPs or MEPs
*evoked potentials
How are SSEPs change when volatile anesthetics are used?
decreased amplitude
↑ latency?
Preop testing for spine surgery includes, what?
textbook answer
CBC (platelets) coagulation studies chest xray PFTs ECG ECHO
What are some positioning considerations for spine surgery?
- Keep head/neck neutral during laryngoscopy
2. place BILATERAL bite blocks to the molars if evoked potentials are being monitored d/t risk of biting down
What 3 methods can combat blood loss during spine surgery?
- autologous transfusion
- hemodilution
- cell saver
What vital sign change may occur during spine surgery?
intentional or unintentional hypotension
What are risk factors for POVL?
[ischemic optic neuropathy]
- prone
- > 5 hours
- pre-op anemia
- male
- obese
- hypotension
What is paramount in prone positioning?
alignment and proper padding
- head/neck alignment
- eyes free of pressure
- chest/breast and genitalia free of pressure
- arms padded and positioned
If tucking arms, what do you need?
Have at least 2 IVs
PIVs and Aline should be in place before tucking arms
What is the position for anterior spine surgery?
supine,
- shoulder roll to extend neck
- ETT position, tubing should run over nose and forehead [make sure it is SECURE with tape]
- arms tucked with traction
*have 2 BP cuffs in place or an aline
What percentage of spinal cord injuries are cervical?
~50%
What 3 injuries are cervical spinal cord injuries often associated with?
- head injury
- thoracic fractures
- pulmonary and cardiovascular injury
What 2 injuries are lumbar spinal cord injuries often associated with?
- abdominal injuries
2. long bone fractures
What are 7 anesthetic considerations of spinal cord injuries?
- neuro exam - get baseline!
- airway management - worry about C3,4,5
[C5-T7 innervate the intercostal and abdominal respiratory muscles] - cardiac considerations - loss of sympathetic tone below injury
- autonomic hyperreflexia - can occur if injury is complete and above T5
- succinylcholine-induced hyperkalemia - only if it has been >48H since injury
- Temperature control
What is the treatment of autonomic hyperreflexia?
remove the stimulus and support symptoms
- deepen anesthetic + give vasodilators
Up to ___% of patients with scoliosis have concomitant neuromuscular disease and congenital abnormalities.
25%
How is the severity of scoliosis determined?
by measuring the COBB angle
What are 2 preoperative anesthetic considerations for scoliosis surgery?
- PFT
2. cardiovascular considerations
What are 3 perioperative anesthetic considerations for scoliosis surgery?
- posterior vs anterior approach
- surgeries T8 and above
- wake-up test? [TIVA with fast on/off drugs, remi/prop]
A cobb angle greater than ___ can have more pulmonary insult & complications.
60degrees
Scoliosis surgeries are often….
large, long, bloody
Anesthetic management of scoliosis surgery includes:
5
- hemodynamic monitoring
- vascular access
- respiratory support
- hypothermia
- replacement of blood and fluid losses
Why is there a risk of hypothermia during scoliosis surgery?
very long surgery, very involved & lots of blood loss
What portions of the spine are most commonly affected by degenerative spine disease?
lumbar or cervical
What are 3 examples of degenerative spine surgery?
- spinal stenosis
- spondylosis [wear & tear]
- spondylolisthesis [vertebrae slippage]
What pre-surgery test needs to be done if patient has degenerative spine disease?
MRI & thorough neurological exam
8 anesthetic considerations for degenerative spine disease?
- preop assessment
- patient positioning (post vs anterior)
- general vs regional
- spinal cord monitoring
- blood/fluid management
- venous air embolism
- visual loss
- postop management
What are 2 signs of a VAE?
- hypotension
2. drop in ETCO2
What are 3 possible causes of vision loss after degenerative spine surgery?
- optic neuropathy
- retinal artery occlusion
- cerebral ischemia
Why do you hyperventilate a patient who has a VAE?
to get the air out
What are 2 methods of performing upper extremity surgery?
- open
2. arthroscopic
What are 4 procedures included in upper extremity surgeries?
- joint disorders
- fractures
- joint arthroplasty
- entrapment syndromes (nerve impingement)
What are anesthetic techniques for upper extremity surgery?
- GETA
2. regional
The brachial plexus is derived from what nerve roots?
C5-T1
What part of C5-T1 nerves are included in the brachial plexus?
ventral rami
What is the order of nerve classifications?
Roots Trunks Divisions Cords Branches (terminal branches)
What does the brachial plexus supply?
sensory and motor innervation to the upper extremity
What are the 5 terminal branches of the brachial plexus?
- median
- axillary
- musculocutaneous
- radial
- ulnar
What are 4 common shoulder surgeries?
- subacromial impingement
- rotator cuff tear
- arthroplasty (total shoulder)
- clavicle fracture
What is the position used during shoulder surgery?
- beach chair
2. lateral
3 challenges that can be faced in shoulder surgery due to positioning?
- head/neck alignment
- padding & positioning of non-surgical extremities
- cerebral perfusion
3 things to “worry about” during shoulder surgery?
- cerebral perfusion
- IV access
- airway access
The beach chair position has been associated with what 4 negative effects?
- decreased cerebral perfusion
- blindness
- stroke
- death
How can we better monitor patients in beach chair?
- BP cuff on upper arm
2. a-line transducer level with the circle of Willis
What is the surgeon going to ask for during shoulder surgery?
lower BP, hypotension
**we need to keep cerebral perfusion adequate by keeping BP up!
What kind of block can be used for shoulder surgery?
interscalene block (ISB)
What level block is an interscalene block?
root level
An interscalene block is the primary brachial plexus block for procedures involving…
the shoulder and proximal upper arm.
Where are the nerve roots of C5-T1 found?
Between the anterior and middle scalene muscles
What 3 procedure locations indicate an interscalene block?
- shoulder
- proximal humerus
- lateral 2/3 of clavicle
What are the landmarks for placement of an interscalene block? (4)
- sternal head of the SCM muscle
- clavicular head of the SCM muscle
- upper border of the cricoid cartilage
- clavicle
If placing a block with a landmark technique, what should also be used?
nerve stimulator
How is the needle inserted for an interscalene block?
between the anterior and middle scalene muscles,
no more than 2-3cm deep (in most patients)
What kind of transducer is used for an interscalene block?
high frequency linear array
Where do you start scanning to place an interscalene block?
supraclavicular fossa, scan cephalad
How is the needle inserted when placing an interscalene block?
lateral to medial
How much LA is injected when placing an interscalene bock?
20mL, but only administer 5mL at a time
What are 2 common side effects of an interscalene block?
- diaphragmatic hemiparesis d/t blockade of the phrenic nerve
- Horner’s syndrome [Ptosis, miosis, anhydrosis] → stellate ganglion blok
What nerve roots can be missed with an interscalene block?
C8 & T1
Where does the vertebral artery enter the spinal column?
C6
Who should not get an interscalene block?
resp insufficiency, COPD
What are 5 common surgeries of the arm/hand?
- surgical repair of fractures (humerus, radius, ulnar, hand
- arthroplasty
- amputation
- ulnar nerve transposition
- carpal tunnel release
What are 3 positions for surgery of the arm/hand?
- beach chair
- lateral
- supine
What three blocks can be used for arm/hand surgery?
- supraclavicular
- infraclavicular
- axillary
What are 2 options for the type (not location) of blocks used in arm/hand surgery?
single shot vs catheter placement
What type of surgery can a Bier block be used for?
hand surgery
How is the patient positioned for a supraclavicular block?
supine
What type of transducer is used for a supraclavicular block?
high frequency linear array
Where is the transducer placed for a supraclavicular block?
supraclavicular fossa behind the clavicle
How is the needle inserted during a supraclavicular block?
lateral to medial
What is the volume of anesthetic used during a supraclavicular block?
~20mL
What nerve is often missed during a supraclavicular block?
suprascapular nerve
What are 2 common side effects of a supraclavicular block?
- stellate ganglion block (Horner’s syndrome)
2. diaphragmatic hemiparesis (phrenic nerve block?
What causes diaphragmatic hemiparesis?
phrenic nerve block
What is another name for Horner’s syndrome?
stellate ganglion block
A supraclavicular block has increased risk of what 2 complications?
- vascular puncture
2. pneumothorax
A supraclavicular block is performed at what level?
trunks
What is the indication for a supraclavicular block?
upper extremity surgery below the shoulder
What 3 landmarks are used to place a supraclavicular block?
- lateral insertion of the sternocleidomastoid in the clavicle
- clavicle
- patient’s midline
What position is a patient in during placement of a supraclavicular block?
- semi-sitting, head turned away
- lower the shoulder & flex the elbow
- forearm on lap, wrist supinated
What level block is the infraclavicular block?
cord level
What is the infraclavicular block used for?
an alternative to the supraclavicular block in patients with severe COPD or respiratory insufficiency
How are the cords labeled?
by their relation to the axillary artery
What are the 3 cords labeled as/named?
lateral, posterior, medial
How is the patient positioned for an infraclavicular block?
supine
How is the transducer placed for an infraclavicular block?
in a sagittal plane below the clavicle, medial to the coracoid process
In what plane is the transducer placed for an infraclavicular block block?
sagittal
How is the needle inserted when placing an infraclavicular block?
cephalad to caudal
How much volume of LA is used for an infraclavicular block?
20-30mL
What kind of transducer is used for placement of an infraclavicular block?
either high or low frequency, linear or curvilinear array transducer
What additional step may needed when placing an infraclavicular block?
SQ injection of Lidocaine may be needed, this block can be painful!
What 2 vascular structures need to be considered when placing an infraclavicular block?
- thoraco-acromial artery
- pectoral veins
doppler will help identify & avoid these
Where do the thoraco-acromial artery and pectoral veins pass?
between the pectoral muscles;
doppler will help identify & avoid these
What are indications for an infraclavicular block?
block of the arm below the shoulder (hand, forearm, elbow, AV fistula)
What is the anatomy of the infraclavicular block?
3 cords that surround the axillary artery; lateral cord is the most superficial, posterior is next, medial cord is deepest and BELOW the axillary artery.
Where are the 3 cords in relation to the axillary artery?
surrounding the axillary artery.
lateral cord is the most superficial, posterior is next, medial cord is deepest and BELOW the axillary artery
Which cord contains the median nerve?
half is in the lateral cord and half is in the medial cord
What nerve is entirely contained within the posterior cord?
the radial nerve
Where is the musculocutaneous nerve in relation to the cords?
outside of the cords but very close to the lateral cord
*so you may miss blocking this nerve
Why does the anatomical location of the musculocutaneous nerve matter?
you might miss blocking it when performing an infraclavicular block!
What are the 4 landmarks for the infraclavicular block?
- clavicle
- jugular fossa or notch
- acromioclavicular joint
- coracoid process
What position is the patient in for placement of an infraclavicular block?
semi-sitting with head turned away
What level block is an axillary block?
terminal branches
An axillary block is good for what type of procedures?
procedures below the elbow
Are axillary blocks becoming more or less popular?
less.
ultrasound has made other blocks more efficient with less complications
Why is an axillary block not attractive?
multiple injections required
What is the nerve anatomy of the apex of the axilla?
the three plexus cords form
the main terminal nerves of the upper extremity
At the level of the coracoid process, what change in nerve anatomy occurs?
axillary and musculocutaneous nerves leave the plexus
at the level of the coracoid process
Where does the axillary and musculocutaneous nerves leave the plexus?
at the level of the coracoid process
Where do three plexus cords form
the main terminal nerves of the upper extremity?
the apex of the axilla
Which nerve is frequently missed during an axillary block?
the musculocutaneous nerve
How is the patient positioned for an axillary block?
supine
Where is the transducer placed for an axillary block?
in the crease formed by the biceps and pectoris major
How is the needle inserted for an axillary block?
lateral to medial
What is the volume of LA used for an axillary block?
20-30mL
What are the 5 landmarks of an axillary block?
- pulse of axillary artery
- coracobrachialis muscle
- pectoralis major muscle
- biceps muscle
- triceps muscle
How is the arm positioned for an axillary block?
arm abducted 90 degrees, elbow flexed
Where is the arterial pulse palpated when placing an axillary block?
at the level of the major pectoralis muscle
How can lower extremity surgeries be performed?
open or arthroscopic
What are 3 common lower extremity procedures?
- arthroplasty
- fractures
- cartilage and ligament repair
Where does the LUMBAR plexus arise from?
from the ventral rami of L1-L4
occasionally T12
What are 3 major nerves of the lumbar plexus?
and 2 others?
- femoral n
- obturator n
- lateral femoral cutaneous n
- ilioinguinal n
- iliohypogastric n
Where does the LUMBOSACRAL plexus arise from?
L4/5 - S1-5
What is the major nerve of the lumosacral plexus?
sciatic nerve
Most common hip surgery patients:
frail & elderly
How are patients positioned for hip surgery?
lateral or supine
Hip surgery that is at greater risk of blood loss
extracapular
→ femoral neck, intertrochanteric, subtrochanteric
Why can neuraxial anesthesia be beneficial in hip surgery?
it can ↓ blood loss
Supine position considerations specific to hip surgery (3)
- IV site
- protect genitalia from pressure
- traction injury to lower extremities
What are 3 things to consider when planning an anesthetic technique for hip surgery?
- elective surgery vs traumatic vs revision
- patient population
- surgeon
3 major potential complications of hip surgery
- fat embolus
- venous thromboembolism
- blood loss [to help combat this →→ regional, deliberate hypotension, dilutional anemia]
5 major benefits of regional over general for hip surgery
- less postop cognitive dysfunction
- superior postop analgesia
- decreased incidence of DVT & PE
- rapid postop rehab
- reduced cost of medical care (when you get up and moving you go home faster)
2 reasons regional techniques are used in hip surgery?
- primary anesthetic
2. postoperative analgesia
What kind of neuraxial block can be used for hip surgery?
- spinal
2. epidural
What 2 kinds of peripheral nerve blocks can be used for hip surgery?
- Lumbar plexus block
2. Fascia iliaca block
The lumbar plexus block is also called _____.
psoas compartment block
The psoas compartment block is also called ____.
lumbar plexus block
What are 2 kinds of lumbar plexus blocks?
- continuous
2. single
Complete regional anesthesia for a knee arthroplasty requires ___.
lumbar & lumbosacral plexus blocks
Is knee arthroplasty associated with a lot or little pain?
significant post-op pain
Who is the average knee arthroplasty patient?
elderly with multiple comorbidities.
What is paramount to post-op recovery from a knee arthroplasty?
post-op pain management
What are 2 parts of an ERAS protocol for knee arthroplasty?
- multimodal pain management
2. continuous peripheral nerve block
Anesthetic considerations for knee arthroplasty (3)
- Effective postoperative pain management is
paramount to recovery - Opioids and neuraxial techniques both have
limitations - Enhanced Recovery After Surgery (ERAS) protocols
What is the usual anesthetic for knee arthroscopy?
peripheral nerve block is rarely indicated,
usually LMA
Why is a knee arthroscopy done?
outpatient procedure, diagnosis
What is the normal anesthetic technique for ACL repair?
same as a knee arthroscopy but peripheral nerve block is warranted for analgesic management
What allows the lower leg to hang freely during an ACL repair procedure?
knee bolster,
will open the joint space
What additional support is needed during ACL repair surgery?
non-operative leg support to reduce lower back stress
What is special about the femoral nerve in the lumbar plexus?
it is the largest nerve
What combines to form the femoral nerve?
dorsal divisions of the anterior rami of L2, L3, and L4 spinal nerves
Where does the femoral nerve emerge from?
the lateral border of the psoas muscle, and remains deep to the fascia iliaca
The femoral nerve provides sensory innervation to ___.
anteromedial leg
The femoral nerve block provides anesthesia to ____.
anterior thigh, knee, and medial aspect of lower leg.
Where is the femoral nerve located?
lateral to the artery and deep to the facia lata and iliaca and superior to the iliopsoas muscle
What are the indications for a femoral nerve block?
anterior thigh
knee surgery
How deep is the femoral nerve sheath?
2-3cm beneath skin
What is the patient position for the femoral nerve block?
supine with external rotation of the lower extremity
Where is the transducer placed for the femoral nerve block?
at the inguinal crease
How is the needle inserted for the femoral nerve block?
lateral to medial
How much volume is used for a femoral nerve block?
20mL
What do you need to be UNDER for placement of the femoral nerve block?
the fascia iliaca
What should be done if two arteries are noted when scanning for a femoral nerve block?
scan cephalad until a single femoral artery is identified
Placement of LA ___ suggests successful femoral nerve block, even if no twitches are noted
below the fascia iliaca and lateral to the artery
What structures appear as “nerves” when placing a femoral nerve block?
lymph nodes
How are nerves and lymph nodes distinguished?
scan proximal and distal.
lymph nodes are not continuous and are only seen at specific locations
After placement of a femoral nerve block, ambulation is prohibited for how long?
24 hours
How do you avoid complications such as vascular puncture and local anesthetic injection when placing a nerve block?
observation of the needle tip throughout the procedure & aspiration
What are indications for a fascia iliaca block? (4)
hip, anterior thigh, knee, femur fracture
What is an alternative to a lumbar plexus block?
fascia iliaca block
What are the three nerves targeted in a fascia iliaca block?
- femoral n
- obturator n
- lateral femoral cutaneous
n
How many nerves are targeted in a fascia iliaca block?
3
How much volume is used for a fascia iliaca nerve block?
40mL
What are the absolute contraindications for a fascia iliaca nerve block?
there are no documented absolute contraindications
What are the 2 relative contraindications for a fascia iliaca nerve block?
- uncooperative patient/surgeon
- infection at site
(3. patient refusal! -> from Dr. Pitman)
What are 5 complications of a fascia iliaca block?
- block failure
- intraperitoneal injection (bowel perforation)
- femoral nerve palsy
- quadriceps weakness
- infection (increased with catheter)
What roots does the femoral nerve originate from?
L2, L3, L4
What roots does the lateral femoral cutaneous nerve originate from?
L2, L3, L4
What does the lateral femoral cutaneous nerve carry?
sensory (afferent) information only
What nerve roots does the obturator nerve originate from?
L2, L3, L4
What does the obturator nerve innervate?
innervates a portion of the distal and medial thigh
Where does the obturator nerve run?
cross iliacus muscle, deep to the fascia, to medial thigh
It is important to block the obturator nerve along with what?
the THA (acetabular component)
What is the key to the fascia iliaca block?
volume!
it is a compartment block
40-60mL
How much volume is used for a fascia iliaca block?
40-60mL
When using ultrasound to place a fascia iliaca block, how many “pops” will there be?
2
- fascia lata
- fascia iliaca
What are the “pops” when placing a fascia iliaca block?
- fascia lata
2. fascia iliaca
During placement of a fascia iliaca block, how should the LA spreak?
cephalad
What has been the gold - standard for pain relief following knee arthroplasty?
femoral nerve block
What negative effect has the femoral nerve block been associated with?
falls secondary to quadriceps weakness
What is an alternative block to femoral nerve block, that can provide sensory blockade with minimal motor involvement?
adductor canal block
What kind of block does an adductor canal block provide?
sensory blockade with minimal motor involvement
What are indications for an adductor canal block?
- TKA
- ACL reconstruction
- anterior knee
surgery
[if used with sciatic block, will achieve analgesia below the knee]
What are contraindications for an adductor canal block?
- patient refusal
- infection at site
- allergy to LA
- anticoagulant therapy/coagulopathy
What nerve is targeted in an adductor canal block?
the saphenous nerve
The saphenous nerve is a branch of?
femoral nerve
Where is the saphenous nerve found?
medial side of the knee and ankle
What is the position when scanning for an adductor canal block?
pt is supine, scan at mid-thigh
**KEY: mid-thigh with femoral artery in middle of sartorius muscle
What are the landmarks for location of the saphenous nerve?
nerve is below the sartorius muscle, lateral to the superficial femoral artery & femoral vein
What is the patient position for placement of an adductor canal block?
Patient supine with slight external rotation of
extremity
Where is the transducer placed for an adductor canal block?
distal thigh
What kind of transducer is used for an adductor canal block?
high frequency linear array
What kind of image is used for needle insertion to perform an adductor canal block?
short-axis image, in-plane needle insertion
Where is LA placed when performing an adductor canal block?
in the fascial plane
separating the adductor longus and vastus medialis
below the subcutaneous tissue
How much volume is used for an adductor canal block?
increments of 5mL up to 20mL
Where may nerve branches be located when performing an adductor canal bock?
on both sides of the superficial artery
What can happen if LA is injected into the muscle?
myotoxicity
What additional muscle is blocked during an adductor canal block?
the vastus medialis
What 2 nerves innervate the ankle and foot?
femoral nerve & sciatic nerve
What kind of blocks are appropriate for ankle or foot surgeries?
neuraxial OR peripheral nerve blocks are appropriate in combination with general or monitored anesthesia
What does the lumbosacral plexus supply?
sensory and motor innervation to the posterior thigh, knee, and lower extremity below the knee
(with the exception to sensory innervation provided by the saphenous nerve)
What does the popliteal nerve block target?
the sciatic nerve, slightly proximal to the knee
What does a popliteal nerve block provide?
anesthesia for procedures involving the foot and ankle
How are the nerves bordered in the popliteal fossa?
superiorly and medially by the semi-tendinosus and semi-membranous muscles
superiorly and laterally by the biceps femoris muscle
How is a patient positioned when placing a popliteal nerve block?
patient supine with operative leg elevated
What kind of transducer is used for placement of a popliteal nerve block?
high frequency linear array transducer
Where is the transducer placed for a popliteal nerve block?
in the popliteal crease
What kind of image is used for placement of a popliteal nerve block?
short-axis image
Where is the target location for the popliteal nerve block?
8-10cm above the popliteal fossa, the sciatic nerve is superficial and bifurcates into the tibial nerve and common peroneal nerve
The sciatic nerve bifurcates into what 2 nerves?
- tibial nerve
2. common peroneal nerve
How/where does the tibial nerve run?
midline
How/where does the common peroneal nerve run?
courses laterally along superior
aspect of fibula
What image is viewed when placing a popliteal nerve block?
short-axis image distal of the tibial and peroneal bifurcation
How is the needle inserted when placing a popliteal nerve block?
Needle inserted
in-plane lateral
to medial
How is the LA spread when placing a popliteal nerve block?
Circumferential spread around each nerve
[ensures a dense nerve block]
How can the transducer be repositioned to gain a better view for the popliteal nerve block?
The transducer may have to be angled toward to the
foot to better image the nerves (anisotropy)
When are ankle blocks indicated?
surgical anesthesia and
postoperative analgesia involving the foot
What 5 nerves supply innervation to the foot?
– Tibial n. – Deep peroneal n. – Superficial peroneal n. – Saphenous n. – Sural n. `
How many nerves supply innervation to the foot?
5
Why is it better to use ultrasound when placing a block?
Greater block efficacy even with lower volumes of
local anesthetic
How is a patient positioned for an ankle block?
Supine with foot elevated or extended over the end of
the stretcher
What transducer is used for an ankle block?
High frequency linear array transducer
What is the first thing done when placing an ankle block?
identify vascular structures first
How is the needle inserted when placing an ankle block?
in-plane or out-of-plane
How much LA is used for an ankle block?
3-5mL at each nerve
4 general considerations/complications for orthopedic surgery
important
- Pneumatic Tourniquet
- Polymethylmethacrylate
- Fat Embolism Syndrome
- Deep Vein Thrombosis and Thromboembolism
When is a pneumatic tourniquet used?
to minimize blood loss and provide a
bloodless surgical field
What are the components of a pneumatic tourniquet?
- inflatable cuff
- connective tubing
- pressure device
- timer
What is critical when using a pneumatic tourniquet?
- proper sizing
2. proper inflation
What determines the pressure of inflation of the pneumatic tourniquet?
patient’s blood pressure and the extremity
What is the time limit for the pneumatic tourniquet?
2 hours
What pathophysiology occurs when a pneumatic tourniquet is in use?
Interrupted blood supply leads to tissue hypoxia and
acidosis
• Deflation of cuff – release of metabolic waste –
metabolic acidosis, hyperkalemia, myoglobinemia,
renal failure
When does tourniquet pain occur?
60 minutes: pain/HTN
approximately 60 minutes after inflation of a pneumatic tourniquet, what occurs?
“tourniquet pain”; HTN & pain
^^do not “over treat” with opioids
What is the maximum inflation pressure of the pneumatic cuff when on the upper extremity?
lower extremity?
other?
250mmHG
300mmHG
OR
100mmHg above the patient’s baseline
What is important to document when the pneumatic tourniquet is used in the OR?
“up” time and “down” time
What 5 things will the patient experience when the pneumatic cuff is deflated?
- metabolic acidosis
- hyperkalemia
- renal failure
- ↑ETCO2
- change in core body temperature
What should happen when the pneumatic tourniquet has been inflated for 2 hours?
it should be released for 10 minutes
What is polymethylmethacrylate?
Acrylic bone cement used in arthroplasty
What is the acrylic bone cement used in arthroplasty?
polymethylmethacrylate
What causes bone cement implantation syndrome?
Exothermic reaction that results in expansion and hardening of polymer ;
causes intramedullary hypertension
What is cause of Bone Cement Implantation
Syndrome (BCIS)?
polymethylmethacrylate
Absorption of polymethylmethacrylate results in: (3)
– Decreased systemic vascular resistance
– Hypotension
– Hypoxemia
aka: bone cement implantation syndrome
What are the 3 risk factors for bone cement implantation syndrome?
- Pre-existing cardiovascular disease or pulm HTN
- ASA Class 3 or higher
- Pathologic fracture, intertrochanteric fracture or long-stem
arthroplasty
What is the treatment of bone cement implantation syndrome?
- Discontinuing nitrous during cementation
- Maximizing inspired oxygen concentration
- Euvolemia
- Creating a vent hole in distal femur
- High-pressure lavage
What is fat embolism syndrome associated with?
traumatic injury and surgery to long bones
What is the incidence of fat embolism?
3-4%
What are the 6 risk factors for fat embolism?
- Age (20-30)
- Male
- Hypovolemic shock
- Bilateral total knee
replacement - Rheumatoid arthritis
- Intramedullary
instrumentation
4 major s/s of fat embolism:
- Petechia
- Hypoxemia
- CNS depression
- Pulmonary edema
7 minor s/s of fat embolism:
- Tachycardia
- Hyperthermia
- Retinal fat emboli
- Urinary fat globules
- Decreased platelets/Hct
- Increased sed rate
- Fat globules in sputum
Treatment of fat embolism syndrome includes (5)
– Early recognition – Reversing contributing factors (hypovolemia) – Stabilization of fractures – Aggressive pulmonary support – Pharmacologic therapy
Without prophylaxis, DVT develops between __ of orthopedic patients
40-80%
What are 6 risk factors for development of a DVT/PE?
- s/p hip fx
- advanced age
- immobility
- previous DVT
- cancer
- pre-existing hypercoagulable state
What are 3 complications of arthroplasty?
- SQ emphysema
- pneumomediastinum
- tension pneumothorax
What are the size of the irrigating solution bags?
3-5L
What is important to remember when there is use of irrigating solution?
compare fluid in / out
Large volumes of absorbed irrigation fluid can lead to:
- volume overload
- CHF
- pulmonary edema
- hyponatremia (if sterile water is used)
