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Adv Principle Oral > Orthopedic Surgery > Flashcards

Orthopedic Surgery Flashcards

1
Q

Tourniquet considerations?

A
  • 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
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2
Q

Brachial plexus overview?

A
  • 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)
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3
Q

4 major UE blocks?

A

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
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4
Q

What type of block is indicated for shoulder and upper arm surgery?

Indications and goals for this block?

A

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
  • 3 major landmarks for placement- sternocleidomastoid muscle, clavicle, acromion
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5
Q

What block would be adequate coverage for surgery on the upper arm to hand?

Indications and goals of this block?

A

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
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6
Q

What block provides coverage for surgery on the arm below the elbow?

Indications/goals?

A

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
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7
Q

Complications of interscalene block

A
  • 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 (ptosis), miosis, anhidrosis, enophthalmos,
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8
Q

Complications of supraclavicular block?

A
  • Pneumothorax
  • Vascular puncture
  • Phrenic nerve block with hemiparesis of diaphragm (less common than interscalene)
  • Horner’s syndrome (less common than interscalene)
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9
Q

Complications of infraclavicular block?

A
  • 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
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10
Q

What is blocked in an axillary nerve block?

A
  • BLOCKED:
    • Median nerve
      • Superior (anterior) to the axillary artery
    • Ulnar nerve
      • Inferior to the axillary artery
    • Radial nerve
      • Posterior to the axillary artery
  • NOT BLOCKED/often SPARED:
    • Musculocutaneous nerve
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11
Q

Indications for axillary nerve block?

A
  • Indications: below the elbow (forearm/hand)
  • Block: ulnar, radial and median nerves
    • Musculocutaneous nerve frequently not anesthetized; requires separate block
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12
Q

What is a bier block?

Indications?

A
  • 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)
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13
Q

What is necessary to complete a bier block? Absolute and relative contraindications?

A
  • Necessary:
    • Cooperative patient
    • Record tourniquet times
    • NEED supplemental postop analgesia!!
  • Absolute Contraindications & Relative contraindications
    • Complications: tourniquet failure → local anesthetic toxicity
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14
Q

Technique for bier block?

A
  1. Start IV on operative hand/wrist (distal)
    1. Place as close to sx site (ex: dorsum of hand* or AC)
  2. Exsanguinate arm
    1. elevate (2-3 min → passive venous drainage) and wrap with tight band (Esmarch band)
  3. Double tourniquet- inflate upper (proximal) cuff to 250 mmHg
  4. Inject 30-50 ml 0.5% lidocaine (preservative free)
    1. Will see blanching (+ analgesia) ~5-10 min
    2. preservative free → decrease risk thrombophlebitis
    3. NO epi
  5. *When pt. begins complaining of discomfort in arm, inflate distal tourniquet and deflate upper tourniquet (25-30 mins)
    1. 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.
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15
Q

Risks for bier blocks?

A

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
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16
Q

Anesthetic management and technique for shoulder arthroscopy?

A
  • 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
  • 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
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17
Q

Shoulder arthroplasty indication, duration and position?

A
  • 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)
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18
Q

Shoulder arthroplasty technique and considerations?

A

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
  • Tranexamic acid (TXA)
  • Embolic syndromes
    • Prone to DVT/PE
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19
Q

Positioning challenges r/t lateral decubitus (sometimes used in shoulder procedures)

A
  • 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)
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20
Q

Respiratory consideration in lateral decubitus position?

Positioning challenges?

A
  • 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)
  • 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)
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21
Q

Complications for beach chair sitting position for shoulder procedures? Hemodynamic changes?

What to check in head position?

A

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)

Head position

  • 2-3 fingers underneath chin strap
  • No extend/flex
  • Head turned slightly away from sx site
  • Eyes protected
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22
Q

Positioning for hip arthroplasty?

A
  • 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.
23
Q

Considerations for general anesthetic for hip arthroplasty?

A

(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
24
Q

Regional anesthesia for hip arthroplasty? considerations?

A
  • 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
25
Q

Blood loss in hip arthroplasty?

A
  • Deliberate hypotension (Diltiazem, nitroprusside, ntg, beta blockers) or regional anesthesia recommended to decrease
  • HIPS- no tourniquet = ­ BL
    • (neuraxial anesth will decrease BL- LA will cause peripheral vasodilation will decrease BP → decrease BL)
  • Autologous donation
  • Cell saver
  • Tranexamic acid (TXA)*
26
Q

TXA administration in hip arthroplasty?

A
  • decrease BL 29-54%
  • Antifibrinolytic
    • MOA: Inhibits conversion of plasminogen to plasmin
    • Synthetic derivative of lysine by blocking lysine binding sites, inhibits conversion to plasminogen to plasmin, reducing fibrin degeneration and preserving/stabilizing fibrin mesh (produced by 2ndary hemostasis)
      • HELPS CLOT, PREVENTS BREAKDOWN OF CLOTS
      • Complications:
        • PE/DVT*
        • NO kidney/liver dx
  • Dosing: depend on fibrinolytic response according to the type of surgery
    • 10 mg/kg loading dose prior to incision
      • Followed by 1 mg/kg/hr infusion (app dosing wont cause PE/DVT)
  • Optimal dosing is probably procedure-specific
    • Low protein binding (3%)
    • 5% metabolized by liver
    • 95% excreted unchanged by kidneys
    • Elimination ½ life @ 2 hrs
27
Q

What is methyl methacrylate?

A

MMA (bone cement)

  • Binds prosthetic with bone.
    • Composition: (2)
      • PEARLS- small particles of prepolymerized MMA (white powder)
      • Liquid monomer
  • Cement mixing causes exothermic reaction; expands causing pressure against bone surface
    • 2 are mixed → catalyst causes polymerization process → hardens → pearls sealed w/in monomer
    • Grout/filling of empty spaces (no adhesive properties) → tight hold of implant/bone surface
  • Intramedullary hypertension pushes fat, air, and marrow into the femoral venous channels.
  • Concerns:
    • Vapors harmful
    • Irritant to skin
    • Reproductive system issues → no preg providers
28
Q

What is bone cement implant syndrome?

A

Physiologic changes for 2-17% w/ methyl methacrylate (MMA)→circulating monomers. more recent theories say it’s an embolus of some sort

  • SEE W/TIME OF INJECTION:
    • decrease SVR, BP, HR, hypoxia, cardiac arrhythmias
    • ­increase PVR
    • loss consciousness (under neuraxial tech)
    • cardiac arrest
  • 1st SIGN
    • GA = decrease ETCO2
    • Regional = dyspnea/altered sensorium
  • Tx: turn off N2O, 100% O2/Aggressive fluids/ Correct hypotension w/ alpha agonists
  • Prior to cement:
    • BP should be optimized, turn to 100% O2, have full bags of fluids on pressure bags, inotropes, fluid bolus
    • Document cement timing on record
29
Q

What is post cement hypotension?

A
  • Profound hypotension immediately after insertion of cemented femoral prostheses has resulted in cardiac arrest and death
  • Uncommon during elective primary total-hip replacement but not uncommon in certain high-risk groups.
    • Admin → Emboli and debride can travel to lung/heart → causes RV heart dysf → CV collapse
  • Hypotension is related in some way to the use of cement. Possible explanations are:
    • Caused by direct vasodilation or cardiac depression from methylmethacrylate.
    • Caused by the forced entry of air, fat, or bone marrow into the venous system, with resultant pulmonary emboli.
30
Q

What is post cement hypoxia? Postoperative mgmt?

A
  • Hypoxia: immediately after insertion of a cemented prosthesis and for up to 5 days into the postoperative period.
  • In the event of hypoxemia:
    • FIO2 100%
    • Rule out:
      • atelectasis of the dependent lung, hypoventilation, fluid overload.
    • Grade 1: moderate hypoxia (SpO2 < 98-4%, SBP decrease > 20%)
    • Grade 2: severe hypoxia (SpO2 < 88%, SBP decrease > 40%)
    • Grade 3: CV collapse (CPR)
  • May be a result of the embolic effects of shaft cement or fat embolism caused by expansion.
  • Postoperative management:
    • Nasal oxygen
    • Pulse oximetry for several days
    • Appropriate fluid management/ diuresis.
31
Q

Risk reduction for BCIS?

Who is in the high-risk group for BCIS?

A
  • Preop assessment/ evaluation- identify high risk patients
    • ASA 3 & 4
    • Older Age
    • Impaired CV/pulm (pulmHTN)
    • Boney metastasis
  • Anesthetic technique
    • maintain normovolemia
    • high inspired concentrations of FiO2
    • reduce MAC if using volatile agent → not as much CV compromise
  • Consider fluid bolus prior to implantation
  • Invasive hemodynamic monitoring
  • Intraoperative cardiac output monitoring
  • Vasopressors & positive inotropic agents on standby
  • Surgeons: know this is possibility → will announce
    • Lavage intramedullary canal of femoral shaft
    • Maintain hemostasis
    • Non-cemented prostheses → pts get readmitted..
    • Drill vent hole in distal femoral shaft
32
Q

What is fat embolism syndrome?

A
  • 72 hrs post-op long bone fracture
    • Brain:
      • Confusion
    • Skin:
      • Petechial rash (chest)
    • Pulm: 1st sign (75% pts)
      • decrease arterial O2
      • Dyspnea
      • Diffuse alveolar infiltrates
      • Pulm edema
      • Sudden decrease ETCO
        • Progress to resp failure (10%)
  • EKG changes / tachycardia
33
Q

What is a lumbar plexus block?

A
  • Femoral, lateral cutaneous, obturator nerves
    • Sx: femoral shaft/neck fractures, knee (ant thigh) → not adequate alone for sx of LE bc contributing innervation of sciatic nerve
    • not used often, difficult technique and frequent failure
  • Motor & Sensory- Hip/Anterior Thigh/Knee
  • Sensory- medial upper and lower leg/ankle
    • Positioning:
      • LDP w/ slightly forward tilt
      • Nerve stimulator (put sx side over dependent leg → see response)
    • Landmarks:
      • Midline of spinous processes
      • Iliac crest
      • Needle insertion- 4 cm lateral to midline
35
Q

Indications, pros and cons to sciatic nerve block?

A
  • Indications:
    • Anesthesia/analgesia to posterior distal thigh, posterior knee, lower leg/ankle/foot for surgery.
      • Ex: TKR
  • Advantage:
    • Complete blockade of leg in combo with femoral nerve block
  • Disadvantage:
    • Deep nerve structure → difficulty to identify (US + nerve stim)
    • Motor blockade can limit post-operative ambulation/physical therapy (foot drop)
      • So dense of block (may just do FNB w/ adjunct)

May need to add saphenous or femoral NB to achieve medial aspect of knee

36
Q

Femoral nerve block motor/sensory blockade?

A
  • Largest branch of lumbar plexus
    • Formed by dorsal divisions of anterior rami L2-4 spinal nerves
    • Sx: Postop analgesia for anterior thigh/knee
  • Motor Innervation: Quads and sartorious
  • Sensory: Anterior thigh, anterior/medial knee, medial lower leg/ankle (saphenous n.)
37
Q

What is the sciatic nerve?

A
  • Nerve roots L4-5 + S1-3 (larges nerve in body)
    • Lumbosacral trunk- anastomosis of last 2 lumbar nerves w/ anterior branch of 1st sacral nerve
  • Exits the pelvis at greater sciatic foramen, below piriformis muscle, descends b/t greater trochanter of femur and ischial tuberosity
  • Travels under gluteus maximus
  • Separates mid-thigh into:
    • Tibial and Common Peroneal nerves
  • Mixed Motor and Sensory Nerve
    • Motor- posterior thigh, leg, and foot
    • Sensory - skin of posterior thigh/knee, lateral leg, foot
39
Q

Popliteal nerve block? indications and advantage?

A
  • Common and useful block
  • Two nerves: Tibial and Common Peroneal together
  • Indications: ( BELOW KNEE)
    • Ankle and foot surgery, debridements, Achilles tendon, saphenous vein stripping
  • Advantage:
    • Spares posterior thigh (hamstring) muscle → don’t lose as much motor strength
      • Facilitates early physical therapy, post-op ambulation
40
Q

Adductor canal block coveragE? indications? advantage?

A
  • Saphenous nerve (sensory) – branch of femoral
    • Anterior, medial knee/leg → picture!
    • Medial lower leg and ankle
  • Indications:
    • Knee analgesia (TKA, ACL, Foot/Ankle)
    • Supplement sciatic blocks (foot/ankle involving medial aspects), supp knee arthroplasty
  • Advantage:
    • Spares quadriceps (motor)
    • Allows for early ambulation/physical therapy
42
Q

Ankle block indication? nerves blocked?

A
  • Indicated for below the ankle procedures
  • Needle 22 G, 38mm B-bevel
  • Volume = 5-7ml per nerve
    • Do not use epinephrine
  • Essentially a field block—no nerve stimulator or US necessary
  • Nerves (5): field block
    • Posterior tibial nerve—posterior tip of medial maleolus and is located posterior to tibial artery
    • Deep peroneal nerve—lateral to dorsalis pedis pulse between the extensor hallucis longus and extensor digitorum longus
    • Saphenous nerve—2cm lateral to deep peroneal nerve in subcutaneous tissue
    • Superficial peroneal—blocked with a “ring” of subcutaneous LA to lateral aspect of ankle
    • Sural nerve—1cm distal to tip of lateral malleolus in subcutaneous tissue
43
Q

Femoral nerve block indications?

A
  • Surgery to anterior thigh/knee
  • Quadriceps muscle bx, quadriceps tendon repair
  • Knee arthroscopy/ACL, AKA/BKA, or TKR → may need to supp w/ opioid for pain control
  • Complete blockade of lower extremity when combined with sciatic nerve block
44
Q

Femoral nerve block disadvantages? contraindications?

A
  • Disadvantage:
    • Loss of Quadriceps (motor) strength and control
      • Limits early postoperative ambulation and physical therapy (i.e. post knee replacement/reconstruction) (quad weakness)
      • Falling out of favor in lieu of Adductor Canal Block (keeps motor)
  • Contraindications:
    • Pre-existing femoral neuropathy
    • Local infection/Enlarged groin lymph nodes
47
Q

What is an IPACK block?

A

Infiltration of Popliteal Artery and Capsule of Knee → MUSCLE STRENGTH SPARING TECH

  • The IPACK block is performed for pain relief of posterior compartment of knee by anesthetizing the perforating branches of the sciatic nerve to periosteum without causing a foot drop (sciatic block does this but motor weakness left).
    • LA in b/t spaces of Popliteal artery and posterior capsule of knee
  • The IPACK is useful in surgical procedures such as: ACL repair with Allograft or patella tendon harvest (Avoid in Hamstring graft) or Total Knee Replacements.
    • Supplement w/ ACB or FNB
  • Common peroneal nerve palsy (CPNP) following total knee arthroplasty 0.3-0.4% after TKA.
    • Prolonged TQ use
    • Neuropraxia from mechanical stretching
    • Rheumatoid Arthritis
48
Q

Anterior vs posterior approach for spine sx?

A

Anterior: (ACDF- anterior cervical disc fusions)

  • For access to upper thoracic and cervical spine
    • C/S issue already → may want fiberoptic/glidescope
  • GETA – awake FO?
  • Supine, bilateral upper extremities tucked
  • IV Access- w/ add. IV
  • Airway edema- extubation issue
  • EBL – minimal if no vascular injury
  • SSEP

Posterior:

  • For access to mid thoracic spine and below.
  • GETA on stretcher
  • Prone, chest rolls
  • Arms at the side of the head (superman) or tucked
  • IV Access – does it work?
  • Facial edema/eyes – tell them to expect edema post op
  • EBL
  • Facial pressure points, groin and breasts.
  • SSEP
49
Q

Lateral approach considerations? (spine sx)

A
  • For access to thoracic spine – help visualize/access anterior thoracic spine
    • Ex. Lateral lumbar interbody fusion
    • Vertebral body fusions, SC decompression, scoliosis, etx
  • Considerations:
    • May need one-lung ventilation
      • double-lumen ETT, bronchial blocker, lung packed
    • A-line to check ABG’s
    • Pad pressure points
    • Axillary chest roll
50
Q

Surgical and anesthesia considerations for cervical spine surgery?

Common complications?

A
  • IS THE NECK STABLE? ASK!
  • Position head to patient comfort while awake. Avoid “sniffing”. Avoid cricoid pressure.
    • Intubation
      • Consider awake fiberoptic
      • Long procedure w prolonged traction- may be prudent to leave intubated at end

Anesthetic considerations

  • Requires GA
  • Indications: Trauma, spinal stenosis, tumor, arthritis
  • Airway compromise and vascular injury can occur
    • Hematoma/carotid artery damage → rapid blood loss
      • IMPEDE AW
    • Unilateral recurrent nerve damage- from instrumentation
  • Post-op pain-cervical plexus block

Common Complications:

  • Dysphagia
  • Soft tissue swelling
  • Dural penetration
  • Esophageal penetration
  • Mechanical failure
  • Wound infections
    • Reasons why we don’t place OG tube
51
Q

Ant and post approach for cervical spine sx?

A
  • Weighted plates can be provided to open up joints for c/s to visualize
  • Anterior approach-most common-esophagus and trachea medial & sternocleidomastoid and carotid sheath lateral. Following discectomy, vertebrae fused w bone, plates, and/or screws to prevent dislocation
    • Retraction of trachea extremely stimulating
    • Arms tucked to sides-assure IV access (extensions)
  • Posterior cervical decompression
    • Sitting: air embolism
    • Prone: eye damage, fluid overload and airway edema
52
Q

Assessment after SCI?

A
  • respiratory insufficiency
    • Monitor at level of injury
      • Muscles at C5 nerve root → diaphragm paralysis (respiratory issues!!)
  • AW obstructions
  • Rib fractures
  • Chest wall/facial trauma
53
Q

What is spinal shock?

A
  • Immediately after SC injury and last up to 3 weeks
  • Injuries at or > T5 injury → hypotension
    • d/t Physiologic sympathectomy occurring from injury → decrease tone on splenetic vascular beds
      • lesions on T1-T4 → decrease HR)
      • Hypotension from SCI DO NOT respond well to fluids/pressors → if try fluids can lead to pulm edema
54
Q

What is autonomic hyperreflexia?

A
  • Autonomic hyperreflexia (complete transection injury >T5)
    • 85% pts
    • Severe HTN w/ decrease HR from baroreceptor reflexes from continuous vasoconstriction
      • Triggering episodes: bladder/rectal distention → sz, intracranial hem, MI
      • Tx: immediate removal of stim, deepen anesthesia, vasodilators
55
Q

Scoliosis considerations?

Ventilation considerations?

A

(4% of pop- 70% ideopathic)

  • Lateral and rotational curvature of spine
  • Surgery indicated when:
    • Cobb angle = >50 deg in thoracic area
    • > 40 deg in lumbar
  • Associated with:
    • Restrictive pulmonary dysfunction: chronic hypoxia, hypercapnia, pulmonary vascular constriction (pulm HTN)
    • Eventually leading to → RV hypertrophy and cor pulmonale
    • Scoliosis frequently seen in patient with- congenital heart disease, MV prolapse, coarctation of aorta, cyanotic heart disease, (suggesting a common embryonic insult of colalgen defect)
  • Restrictive lung ventilation strategies
    • 4-6 mL/kg TV
    • Rate 14-18 breaths/min
    • I:E 1:1 or 2:1
    • Judicious peep (5-10)
    • Titrate FiO2 Spo2>90%
56
Q

What is SSEP?

A

Somatosensory Evoked Potentials (SSEP): check for SC & nerve integrity

  • Helps determine surgical impingement on spinal roots
  • Sensory- Monitor dorsal column pathways of posterior spinal cord
    • SSEPS recorded by stimulating peripheral afferent nerves
    • Intact nerve → electrical potential will transmit to contra lateral sensory cortex.
  • Recording electrodes are placed on the scalp and on the cervical spine.
  • Amplitude, shape, and latencies of the responses are monitored.
  • Need to establish a reproducible baseline recording prior to any positioning or surgical manipulations is important.
  • Changes from the baseline responses are the most important indicators of neurological dysfunction.
  • Latency & Amplitude → need baseline measurement
  • Anesthetics disturb L & A
    • VA **
57
Q

What is MEP?

A

Motor Evoked Potential = Anterior SC

  • Motor Evoked Potentials
    • *monitor descending motor pathways*
  • Concern:
    • Amplitude = > 50% decrease
    • Latency = > 10% decrease
      • Causes: damage by ischemia, metabolic change, mechanical trauma, compression
  • Recorded from muscles following transcranial stimulation of the motor cortex to the peripheral muscles
  • To ensure the integrity of the descending motor tracts of the spinal cord
  • Agents:
    • VA- sensitive**
    • IV anesthetics- less than VA
    • Opioids ok
      • Good drugs: propofol, remi, ketamine, dexmedetomidine
58
Q

Anesthetic consideration with SSEP monitoring?

A

*Concern for nerve damage:

  • Amplitude = > 50% change
  • Latency = > 10% change
    • Sx cause? Or hypotension, hypothermia, change anesthetic tech, etc

Anesthetic Considerations:

  • Inhaled Anesthetics can alter the evoked responses significantly
    • VA = Dose dep decrease amplitude & ­increase latency
  • VA: (unreliable results).
    • 0.5 MAC w 50% N2O
      • decrease amplitude
      • ­increase (prolong) latency
        • Need to keep anesthesia consistent and notify them of changes to plan
  • IV anesthetics no impact → TIVA best (balanced technique good)
  • NMB do not adversely affect → SSEP used for posterior sensor component of spinal cord
  • Decreases in SSEP signal despite no change in anesthetic or no surgical changes may mean hypotension! Nerves get blood too!

Adv Principle Oral (9 decks)

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