Anesthesia for Orthopedic Surgery Flashcards
Preoperative consideration for orthoepdic patients
- Airway assessment- fiberoptic, video laryngoscope
- Neurologic exam- document baseline neuro issues . cognitive impairement?
- Comorbidities (CV, frailty, neuro, thromboembolic, pulm, etc.)- high rate of arrhythmias, fraility scores, anti-coag d/t increased risk for DVT.
- Able to assess exercise tolerance?– CV related or joint related intolerance?
- Joint mobility issues?- difficulty with positioning
- Opioid use?- Many pt already on opioids
- Anticoagulation use?- recent use?
- Positioning issues?
Tourniquet considerations?
- Used to minimize blood loss and provide bloodless surgical field
- Cuff size- completely encircle limb; width more than half the limb diameter
- Risk- damage to underlying vessels, nerves, and muscles
- Ideally, pressure set
- 100 mmHg above patient’s systolic BP for thigh
- 50 mmHg for arm.
- Tourniquet pain develops over time
- Max duration 2 hours
- Transient metabolic acidosis, increased CO2 levels, and drop in BP with tourniquet deflation
Highest occurring orthopedic procedures?
Knee arthroscopy
Hip replacement
Spinal fusion
Brachial plexus overview?
- Plexus formed by intercommunications among the ventral rami (roots) of the lower 4 cervical nerves (C5-C8) and the first thoracic nerve (T1).
- Motor innervation of all the muscles of the upper extremity, with exception of the trapezius and levator scapula (spinal accessory)
- Sensory innervation to skin with exception of area of skin near the axilla (intercostobrachial)
-
Terminal branches of BP
-
Musculocutaneous nerve
- biceps brachii-flexes below, supinates
- brachialis- flexes elbow
- coracobrachialis- flexes elbow/adducts
- Axillary
- deltoid
- trees minor
- Median (flexion)
- flexor named muscles
- pronator teres
- radial (Extnesion)
- triceps brachii
- ulnar (flexion)
- flexor carpi ulnaris
- flexor digitorum profundus)
-
Musculocutaneous nerve
4 major UE blocks?
Interscalene
- Roots/trunks
- Indicated for surgery for shoulder and upper arm
Supraclavicular
- Trunks/divisions (middle/inferior trunks?)
- Indicated for surgery for upper arm to hand (if you don’t need shoulder coverage)
- close to lung- risk for pneumo
Infraclavicular
- Lateral, posterior, medial cords
- Indicated for surgery for elbow, forearm, hand
Axillary
- Median, ulnar, radial nerves
- Indicated for surgery below the elbow
What type of block provides this coverage?
Indications and goals for this block?
Interscalene block
- indication- shoulder and upper arm surgery
- Goal- local anesthetic spread around superior and middle trunks of brachial plexus, between anterior and middle scalene muscles
- (blocks at level of roots/ trunks
- inferior trunk fibers frequently not anesthesized (C8-T1)
-
ULNAR nerve often not blocked
- Need additional blockade if working in lower arm
- the one block approved for EXPAREL use
-
ULNAR nerve often not blocked
- 3 major landmarks for placement- sternocleidomastoid muscle, clavicle, acromion
Complications of interscalene block
- Ipsilateral phrenic nerve block with ipsilateral diaphragm paralysis
- if this occurs, can loose 25% of pulmonary functions
- caution in severe pulm disease- may do dual technique- nerve stim and US
- never do B interscalene blocks
- Intravascular injection (close proximity to vertebral artery, carotid artery, jugular vein)
- use epi- if change HR–> intravascular
- Hoarseness, dysphagia (RLN blocked)
- Horner’s syndrome- drooping eyelid
Which block provides this coverage?
Indications and goals of this block?
Supraclavicular block
- Indications- upper arm to hand (shoulder- sometimes but will maybe want to use interscalene block)
- coverage mid-humerus to hand
- provides predictable, dense, rapid block
- Goal- local anesthetic spread around lateral border of the clavicular head of SCM, groove between scalene muscles, just lateral to SCL vein
- blocks at level of trunks (middle/inferior)/divisions
- area in armpit not covered- may need intercostobrachial NB
Complications of supraclavicular block?
- Pneumothorax
- Vascular puncture
- Phrenic nerve block with hemiparesis of diaphragm (less common than interscalene)
- Horner’s syndrome (less common than interscalene)
Which blocks provides this coverage?
Indications/goals?
Infraclavicular block
- Indications: elbow, forearm, hand
-
Goal: LA spread at midpoint between coracoid process & medial clavicular head
- Blocks @ level of lateral, posterior, medial CORDS
- Frequently spares intercostobrachial nerve (sensory to upper medial arm)
- Additional LA to fix that
Complications of infraclavicular block?
- Vascular puncture (axillary artery/vein) – proximity
- Pneumothorax (low risk)
- Painful → very deep nerves (difficult to visualize) (con)
- May need more midaz/fent
- Pros:
- *Prevents SE of supraclavicular block
- Decrease complications w/ US, good w/ nerve catheters
What is blocked in an axillary nerve block?
-
BLOCKED:
-
Median nerve
- Superior (anterior) to the axillary artery
-
Ulnar nerve
- Inferior to the axillary artery
-
Radial nerve
- Posterior to the axillary artery
-
Median nerve
-
NOT BLOCKED/often SPARED:
- Musculocutaneous nerve
Indications for axillary nerve block?
- Indications: below the elbow (forearm/hand)
- Block: ulnar, radial and median nerves
- Musculocutaneous nerve frequently not anesthetized; requires separate block
What is a bier block?
Indications?
- IV Regional Anesthesia - ~ lidocaine into venous circulation (UE or LE)
- Sensory/analgesia for sx w/o any other meds
- Easy and complete analgesia w/ bloodless sx field
- Indications: Limited to short procedures
- below elbow, below knee (~1hour)
What is necessary to complete a bier block? Absolute and relative contraindications?
- Necessary:
- Cooperative patient
- Record tourniquet times
- NEED supplemental postop analgesia!!
- Absolute Contraindications & Relative contraindications
- Complications: tourniquet failure → local anesthetic toxicity
Technique for bier block?
-
Start IV on operative hand/wrist (distal)
- Place as close to sx site (ex: dorsum of hand* or AC)
-
Exsanguinate arm
- elevate (2-3 min → passive venous drainage) and wrap with tight band (Esmarch band)
- Double tourniquet- inflate upper (proximal) cuff to 250 mmHg
-
Inject 30-50 ml 0.5% lidocaine (preservative free)
- Will see blanching (+ analgesia) ~5-10 min
- preservative free → decrease risk thrombophlebitis
- NO epi
- *When pt. begins complaining of discomfort in arm, inflate distal tourniquet and deflate upper tourniquet (25-30 mins)
- Additional adjuncts (midaz/propofol acceptable)
- having 2 cuffs helps to decrease tourniquet pain. with the proximal (upper) cuff inflated, LA can get to the area underneath the distal cuff (lower cuff). If pt starts complaining of tourniquet pain, inflate the distal cuff(lower) and deflate the proximal). This should decrease tourniquet pain because LA is covering the portion underneath the cuff now.
Risks for bier blocks?
Tourniquet failure → if large amount of LA admin and not exsanguinated
- LA absorbed quickly (Sz, LA tox, circumferential oral numbness, tinnitus, CV arrest)
-
Avoid:
- Test tourniquet before applying
- Ensure sx 25-30 min
General summary of brachial plexus block distribution?
General information for hand, wrist sx?
- Usually short → 1 hr procedures
- ambulatory sx, straightfoward, minimal blood loss
- great for regional
- Tourniquet used- minimal BL
- Examples: Carpal tunnel release, ORIF fractures, debridement of wound, ganglion removal, Dupuytren’s contracture fasciectomy
Anesthetic management for hand, wrist sx?
-
Anesthetic Management (REGIONAL BEST)
- Local w/ MAC
- surgeon can perform block in surgical field (if no tourniquet required)
- Terminal nerve blocks (radial/ulnar/medial blocks) (if no tourniquet)
- Intravenous anesthesia- Bier block (good for hand)
- BLOCKS:
- Supraclavicular, Infraclavicular, axillary blocks
- General w/LMA or RSI w/ ETT if trauma
- general problem is patient motivation. pt generally don’t want to see/hear anything in OR. limits the ability to do local with MAC.
- Local w/ MAC
Elbow surgery examples and position?
- Examples: cubital tunnel release, ulnar nerve transposition (neuropathies), ulnar collateral ligament reconstruction, ORIF fracture
- Tourniquet used
- Position: supine, lateral, prone (sx preference)
Anesthetic management for surgery of elbow
- General w/LMA or RSI w/ETT if trauma
- Brachial plexus block (Infraclavicular, Supraclavicular*, ISB*) w/ +/- intercostobrachial nerve block for tourniquet
- Sx may need NMB → COMM W/ SX
Shoulder arthroscopy indications?
- Indications
- Rotator cuff tear
- Torn labrum
- Repair of ligaments
- Severe refractory instability
- Removal of inflamed tissue
- Subacromial bursitis
- Arthritis
- Proximal humerus fracture
PAINFUL → optimize pain mgmt, need to start PT soon
- Offer regional (CI: pt refusal/allergic rx)
Anesthetic management and technique for shoulder arthroscopy?
- Approx. 1+ hour procedure
-
Position: Sitting or lateral
- Hemodynamic changes:
- decrease CPP → increase MAP goal
- BP/HR w/ bed position change
- Preemptive fluid bolus, Phenyl/Ephedrine
- Raising HOB slowly
- Consider A-line
- Pulm embolism
- Neck position → cervical perfusion/nerve damage
- Pressure points → PAD
- Hemodynamic changes:
- Technique:
- GETA, GA w/LMA
- communicate with surgeon
- +/- Interscalene or Supraclavicular block (with MAC?)
- Bed turned 90 deg away from machine
- AW access lost
- Sometimes NMB req- communicate with surgeon. don’t want to go in with LMA and then realize patient needs relaxation
- GETA, GA w/LMA
Shoulder arthroplasty indication, duration and position?
- Indications: Arthritis, DJD
- Durations: pot. long procedures up to 3 hrs.
- May not be comfortable for awake patient
- Position: Sitting or lateral position (think complications)
Shoulder arthroplasty technique and considerations?
Technique:
- ETT, GA w/LMA-
- Interscalene or Supraclavicular (CONSIDER REGIONAL TOO)
- NO Tourniquet
Considerations:
- Significant blood loss (EBL ~1-1.5 L)
- Need 2 or more large IV’s, CBC preop, at least T&S
- Hypotensive anesthetic technique
- Set MAP/SBP goal to decrease BL
- VA/Propofol, vasodilator, etc
- DO NOT DO ON PTS W/ carotid stenosis, stroke, poorly controlled HTN pt→ cant autoreg CPP
- VA/Propofol, vasodilator, etc
- Set MAP/SBP goal to decrease BL
- Tranexamic acid (TXA)
- Embolic syndromes
- Prone to DVT/PE
Positioning challenges r/t lateral decubitus (sometimes used in shoulder procedures)
- Frequently reassess eyes, ears, head/neck alignment, legs, hips
- Axillary chest roll (brachial plexus protection)
- BP cuff pressure on lower arm- BP may reflect it is higher than actual pressure (consider placing on leg)
Respiratory consideration in lateral decubitus position?
- Gravity → affects how well lung will perfuse/ventilate
- young/healthy tend to tolerate fine
- Unanesthetized:
- V/Q Non-dependent << Dependent
- Anesthetized:
- Nondependent: V > Q (perfusion does not change from awake)
- Dependent: V < Q (hard to ventilate dep. Lung)
Complications for beach chair sitting position for shoulder procedures? Hemodynamic changes?
Complications
- Potential for nerve injuries
- BP #1
- Cervical spine injury (avoid head dislodgement)
- Consistently check
- Excess flexion of neck
- (may obstruct internal jugular vein—venous engorgement)
- Excess extension of neck may impair CBF—cerebral ischemia
- Macroglossia- MOA??
- Last hrs after sx (bite blocks may put pressure and cause swelling)
- Eye injury
- avoid deliberate hypotensive technique
- avoid pressure on eyes/ears
Hemodynamic challenges
- Decrease BP
- Venous pooling
- Decrease CO
- ¯Decrease Intrathoracic blood volume
- Correctly monitoring BP important (previous lectures says 1 cm rise = 0.75 mmHg decrease)
What to check for with head positioning in beach chair?
- 2-3 fingers underneath chin strap
- No extend/flex
- Head turned slightly away from sx site
- Eyes protected
Anesthesia consideration for procedures of lower extremity?
- Performed under both regional and general
- choice also depends on skill of surgeon
- Regional: studies show decrease BL during total hip
- (And decrease mortality, DVT, LOS, cost)
- Goal: provide post-operative analgesia
- Rapid post-operative rehabilitation- mandatory
-
Reduce post-operative morbidity and mortality (DVT/PE)
- Total Hip 42-57% (DVT)/0.9-28% (PE)
- Total knee 41-85% (DVT)/1.5-10% (PE)
- Hip fracture 46-60% (DVT)/3-11% (PE)
- Use of LMWH (ex. Lovenox) and Coumadin
Characteristics/technique of total hip replacement procedure?
- Technique: SPINAL
- Large incision-iliac crest to mid-thigh
- Muscle relaxation needed to access joint (spinal ideal)
- Femoral head is dislocated from acetabulum
- Arthritic femoral head and portion of neck excised
- Acetabulum & femoral canal reamed to accept cemented (methyl methacrylate) metal/plastic prosthesis
- Cup, ball and stem replace femur head
-
Blood loss 500-1000 ml (~1-1.5 L)
- Hgb threshold for replacement < 10 conservative or < 8g/dL studies show no difference in outcomes
- CV pts → higher threshold for transfusion
Preoperative considerations for hip arthroplasty?
- D/C anti-inflammatory meds at > 1 week prior
- HERBALS ~ 2 weeks d/c
- Joint degeneration: AW assessment!
- Assess flexion, extension, cervical, TMJ
- T&C/autologous/cell-saver
- Optimize pt before sx
Monitoring considerations in hip arthroplasty?
- Elderly w/ underlying disease
- Cardiac function difficult to assess (A-line, CVP?)
- Careful fluid management
- Balances technique (crystalloids/colloids/blood tx trigger)
- Hypoxia and pulmonary edema increase
- Fat or bone marrow emboli → anytime working in long bones
Positioning for hip arthroplasty?
- Anterior approach → spine position
-
Lateral decubitus (HIP)
- V/Q mismatch
- Neurovascular complications
- Head & shoulders in neutral position
- Dependent arm abducted on padded arm rest → ensure IV working
- Axillary artery
- Place ax. roll
- Femoral nerve injury- surgery or positioning related
- Careful with excessive hypotension.
Considerations for general anesthetic for hip arthroplasty?
(can still do regional too)
- Need muscle relaxation
- Definitive pain control plan throughout surgery and post-operative period → get regional before start
- Consider PCA or combined regional techniques for postop
- Patient may be difficult to position – d/t presenting underlying condition
- ASA status and co-existing disease may be an issue.
- Maintain normothermia
Regional anesthesia for hip arthroplasty? considerations?
-
Neuraxial anesthesia
- Spinal
- Spinal/epidural combo
- Lumbar plexus block or psoas compartment block
-
Femoral nerve block
- quadriceps weakness increases postoperative falls
- Adequate IV hydration to avoid decreased BP w sympathetic block (Two 14-16g IVs ideal)
- Neuraxial
- SAB (hypobaric or isobaric) or Epidural- lumbar spine unaffected w rheumatoid
- 250-500 ml fluid bolus to offset sympathetic block
- Considerations
- Patient may be difficult to position → degenerative dx hard to get spinal (general as backup)
- Case length may predispose patient to discomfort
- Regional provides post-op pain control
- Airway control in lateral