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N602 Exam II > Ortho > Flashcards

Flashcards in Ortho Deck (73)
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0
Q

Pathophysiology of Osteoarthritis

A

NON-systemic disease!!

  • Degenerative disease: loss of cartilage & associated w/non-systemic inflammation
  • Articular wear/tear
  • Affects articular surfaces of one or more joints
1
Q

What are a few key anesthetic management considerations for EVERY type of ortho case?

A
  • Comorbidities: CV status & baseline vitals
  • Positioning: effect on pulm/CV, possible nerve injuries
  • Desired vent settings: based on positioning & pt physiology
  • Blood loss: expected & acceptable blood loss
  • Airway concerns?: Fiberoptic/glidescope available
  • Regional vs General
  • Risk factors specific to the type of procedure: prophylactic tx? (DVT proph)
2
Q

OA Clinical Manifestations

A

**Limited physical activity/mobility
Pain
Crepitance
Deformity of involved joints
Swelling of DISTAL interphalangeal joints = Heberden’s nodes
Swelling of PROXIMAL interphalangeal joints = Bouchard’s nodes

3
Q

OA most commonly affects ____ or ___.

A

Hips or Knees

4
Q

OA pt’s are usually on medication? What are we concerned about?

A

NSAIDS = Bleeding! (Consider GIB prophylaxis in preop)

5
Q

Pathophysiology of Rheumatoid Arthritis

A

SYSTEMIC disease

  • Immune-mediated joint destruction with CHRONIC, progressive inflammation of synovial membrane
  • Involves multiple joints in a SYMMETRICAL fashion
6
Q

Systems affected by RA:

A
  • CV: pericardial thickening, valvular fibrosis, conduction defect –> increasing CAD r/t corticosteroids
  • Pulm: effusions
  • Hematology: anemia
  • Endocrine: adrenal insufficiency r/t steroids (stress dose if w/in 6mo)
7
Q

Medication use associated w/RA? What are we concerned about?

A
NSAIDS = Bleeding
Steroids = need stress dose; cardiac/adrenal insuff 
Methotrexate = BM suppression
8
Q

What are the two major things we are concerned w/RA & AIRWAY?

A

Atlantoaxial Instability & Cricoarytenoid Arthritis

9
Q

Describe the Atlantoaxial Instability found in RA pts

A

C-spine issues w/erosion of ligaments by rheumatoid involvement of the bursae around the ODONTOID PROCESS of C2 causes ATLANTO-AXIAL SUBLUXATION with flexion…
Pushes odontoid into foramen magnum –> compressing spinal cord against the posterior arch of C1 —> potentially reducing vertebral BF

10
Q

What type of subluxation is found w/RA pts?

A

ANTERIOR Subluxation is the most common form

11
Q

Consider a fiberoptic intubation if atlantoaxial instibility is > ___.

A

Instability >5mm = fiberoptic intubation w/manual inline stabilization

12
Q

How will Cricoarytenoid arthritis present?

A

Hoarse or inspiratory stridor = narrow glottic opening

13
Q

Anesthetic considerations/concerns for cricoarytenoid arthritis

A
  • Use smaller ETT
  • Post-extubation concerns due to development of airway obstruction -(Judicious use of narcotics or epidural analgesia for pain relief should be considered)
  • Post-op O2
14
Q

Airway assessment for RA pt’s should include:

A
  • Flexion/extension X-rays (65% of RA pts will develop atlantoaxial instability within 2 years – will tell us if we can use glidescope or need to do awake fiberoptic intubation)
  • Neck pain? HA?
  • Neurologic symptoms in arms or legs w/neck motion?
15
Q

Immediate pre-op concerns with RA pt’s (technical difficulties)

A

Starting A-lines & central lines (r/t calcified vasculature)

Positioning issues

16
Q

What is similar between RA & AS?

A

C-spine instability –> consider awake fiberoptic

RA = Subluxation of C2
AS = Fused C-spine
17
Q

Describe the pathopysiology of Ankylosing Spondylitis

A

SYSTEMIC Disease

  • Fused vertebrae starts at sacrum & ASCENDS to cervical spine
  • Ossification of ligaments at bone attachment sites –> progressive ossification involves joint cartilage & disk space of axial skeleton with eventual ankylosis –> immobility & consolidation of joints
18
Q

Who does AS affect most?

A

Men > women

19
Q

AS affects what part of the body?

A

Cervical spine
Hips
Shoulders
Costovertebral joints

**Careful positioning!!

20
Q

Systems affected by AS

A
  • Pulm: Lung function impaired, restrictive lung dx picture, rigid rib cage (DECREASED FRC)
  • CV: Aortic regurg & BBB
  • Verbetral Column: Fused, making lumbar epidural/spinal anesthesia difficult/impossible. May require paramedian approach.
21
Q

What do we take into consideration when deciding between regional or general?

A

1) Pt preference
2) Pt Health/Comorbidities
3) Expertise of anesthesia provider
4) Duration of procedure
5) Surgeon’s preference

**Combined techniques very popular

22
Q

How can we minimize homologous blood transfusions?

A

1) Induced hypotension (on right pt)
2) Intra-op hemodilution
3) Cell savers
4) Preservation of normothermia (Cold pts = bleeding)
5) Lower transfusion “trigger” (cosider ABL)
6) Aprotonin (not on market anymore but Vicky still thought it was nec to bring up- protease inhibitor caused problems w/thromboembolism & kideny dysfxn)

23
Q

Two reasons we use tourniquets

A

Reduce blood loss & surgeon visualization

24
Q

Physiology behind tourniquet pain?

A

Result of unmylinated C fibers (slow conducting) RESISTANT to LA = even w/block still have sx of tourniquet pain

Under GA it causes increased SNS outflow = HTN & Inc HR

25
Q

Onset of tourniquet pain

A

30-90 min after inflation

26
Q

Tx of tourniquet pain

A

Higher MAC– deepen w/IA

Be careful w/narcotics

27
Q

Release of a tourniquet will cause…

A

Release of metabolic byproducts –> INCREASE MV due to an inc CO2

28
Q

When using a tourniquet, how much pressure do you add to a patient’s SBP for an UPPER extremity procedure? How much time is allowed?

A

50-75mmHg

1hr

29
Q

When using a tourniquet, how much pressure do you add to a patient’s SBP for a LOWER extremity procedure? How much time is allowed?

A

100-150mmHg

1.5-2 hrs

30
Q

When using a tourniquet, how much pressure do you add to a PEDIATRIC pt’s SBP?

A

100mmHg

31
Q

When using a tourniquet, what can you do if the surgeon requires additional time after the “max safe time” has been reached?

A

Deflate the tourniquet for 10 min to reperfuse & then re-inflate

**Max safe time = 2hrs

32
Q

Name 5 tourniquet complications

A

1) Nerve injury
2) Post-tourniquet syndrome (PTS)
3) DVT
4) Compartment syndrome
5) Digital necrosis

33
Q

How does post-tourniquet syndrome manifest?

A

Pronounced &, at times, prolonged postop SWELLING of the extremity

34
Q

Nerve injury is the most complication from the use of tourniquets during upper or lower extremities?

A

Upper

35
Q

Physiologic changes associated w/the sitting position/beach chair

A
  • Decreased: MAP, CVP, PAOP, SV, CO & CPP

* Increased: PAO2-PaO2 gradient, pulm vasc resistance & total peripheral resistance

36
Q

Without GA, the physiologic changes associated w/the beach chair position are usually compensated by_______.

A

Increase SVR 50-80% **This is what is blocked by anesthetics

37
Q

What should you take into consideration when caring for a poorly controlled htn pt who needs to be in the beach chair position?

A

Autoregulation of CBF is shifted to the RIGHT = requires higher CPP/MAP to ensure adequate cerebral perfusion (always need an accurate baseline BP).

38
Q

___mmHg drop in BP for every ____cm the ear (level of the head) is above the heart.

A

2mmHg drop in BP for every 2.5cm the ear is above the heart.

39
Q

Anesthetic considerations w/beach chair position

A
  • Avoid deliberate hypotension
  • Tilt legs up after head is up to limit pooling of VR
  • Use SCDs
  • Adequate PRELOAD (500ml pre-op)
  • Know baseline BP preop
  • Questions to ask: Take ACE-I? dizzy/tachy w/position changes?
40
Q

Drugs to consider using w/beach chair position

A
Phenylephrine or Ephedrine
Ketamine 25mg (add to induction dose of propofol; avoid w/severe HTN & AS)
41
Q

Main pre-op anesthetic considerations with shoulder arthroSCOPY vs arthroPLASTY

A
ArthroSCOPY = mostly lateral decub; minimal EBL (1IV); minimal pain
ArthroPLASTY = mostly beach chair; inc EBL to 1L (need 2 IVs); PAIN (need block or PCA)

**Both done w/GA or interscalene block with either beach chair or lateral decubitus position

42
Q

The shoulder is innervated by which dermatomes?

A

C5-6 dermatomes

43
Q

Post op morbidity & mortality r/t lower extremity procedures are usually due to…

A

DVT & PE —> prevent venous stasis w/SCD’s & early ambulation

  • 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
44
Q

Due to the increased risk of DVT & PE w/lower extremity procedures, which medication should always be considered??

A

LMWH – outweigh risk/benefits

45
Q

How long do you wait after administration of LMWH before administration of a block?

A

12hrs = would have to come in the night before

46
Q

How long after administration of LMWH do you have to wait to remove an epidural catheter?

A

8hrs

47
Q

Reaming (drilling within core of a bone to make space for a rod/nail) causes an increase in _____ & _____.

A

blood loss & risk of emboli

48
Q

When can fat emboli syndrome (FES) occur?

A

12-72hrs post op & intraop

49
Q

Triad of symptoms of FES

A

Dyspnea
Confusion
Petechia to chest

***presents as acute resp distress/cardiac arrest

50
Q

Under GA, what would you notice if your pt experienced FES?

A

Decreased arterial oxygenation
EKG changes
Sudden DROP in ETCO2

51
Q

Do lower or upper extremity procedures have the potential for large blood loss?

A

LOWER = large blood loss >1500ml

***Type & cross

52
Q

When taking regional anesthesia into consideration (whether in conjunction w/GA or alone) what should you also be thinking about…

A
  • pt difficult to position?
  • case length predispose pt to discomfort?
  • painful procedure in which pt needs post-op pain control?

**Alwaysssss ASA STATUS & CO-EXISTING DISEASES

53
Q

Use of hypotensive techniques or regional anesthesia REDUCES blood loss by ____ to ___%.

A

30-50%

54
Q

What are your concerns w/having a REVISION ortho procedure?

A

Need to ream bone & old cement = Inc BLEEDING & EMBOLI

55
Q

Describe the physiologic response pt has to metylmethacrylate cement.

A

Cement = exothermic reaction –> intramedullary htn –> pushes fat/air/marrow into femoral venous channels

  • Decreased SVR
  • Hypotension
  • Hypoxia
56
Q

Anesthetic considerations to using methylmethacrylate cement.

A
  • Open fluids if pt can tolerate it
  • 100% O2 even on low flows
  • Phenylephrine gtt ready
  • Watch ETCO2 (will be first sign of CV collapse)
57
Q

Patients at high risk for developing hypotension during THR w/use of cement

A

1) Metastatic CA
2) Removal of hardware
3) Revisions

58
Q

Methylmethacrylate cement causes hypotension by:

A

DIRECT VASODILATION or by forced entry of air/fat/bone marrow into venous system resulting in PULMONARY EMBOLI

59
Q

When do THR pt’s develop hypoxia after using methylmethacrylate cement?

A

Immediately after insertion of cement & for up to 5 days into post-op period

60
Q

How can we prevent hypoxia w/cement use?

A
  • Use NC
  • Pulse ox for several days (can last up to 5 days after insertion)
  • Judicious use of narcotics (avoid hypovent or airway obstruction)
  • Appropriate fluid management/diuresis
61
Q

When dose blood loss occur for TKR vs THR?

A
TKR = blood loss POST-op (r/t tourniquet-- can be increased for 24hrs)
THR = blood loss INTRA-op
62
Q

Typical pt presenting w/fractured neck of femur

A

Old women (>80yo) with dementia after falling in nursing home

63
Q

With fractured neck of femur, what is the most common cause of intra op death?

A

MI & PE

*Also have complications like pneumonia contributing to mortality

64
Q

What time of spinal would a pt w/a fractured neck of femur need?

A

HYPObaric spinal – most likely wont be able to tolerate position changes.

65
Q

Anesthetic considerations for pts w/LE amputations

A
  • Gangrene, septic, chronic dz, trauma = regional a good idea???
  • EBL 250ml
  • High mortality of 10-20%
  • Morbidity: phanton limb 85-95%, wound infection <15%, pneumonia 10-15%, MI 7-10%, emboli 6-19%, CVA 5-10%
66
Q

When is the anterior vs posterior approach used in spine surgeries?

A
Anterior = thoracic & cervical spine
Posterior = mid thoracic & below
67
Q

How do we facilitate a ‘wake-up test’ in the middle of a thoracolumbar spinal surgery?

A

Tell pt ahead of time they will asked to move extremities in middle of case while prone & not be able to talk (practice pre-op). There is a 20% chance of recall.

  • Avoid 0/4 twitches – give incremental doses of MR
  • Watch opioid use & AVOID reversals
  • Turn down IA & turn on low nitrous
68
Q

EBL for a thoracolumbar surgery depends on…

A

of segments fused

69
Q

Most common stimulation site for SSEP in upper vs lower ext?

A
UE = Median nerve
LE = Posterior tibial nerve
70
Q

When using SSEP, what is being monitored?

A

Posterior spinal cord function (sensory) via a current delivered to peripheral nerves. Looks at the…

  • Amplitude
  • Shape
  • Latencies
71
Q

VA effect on SSEP

A

Decrease amplitude/distort electrical signal

72
Q

What does a decrease in SSEP signal despite no change in anesthetic or surgical changes mean??

A

HYPOTENSION