Exam 1: Orthopedic Anesthesia Flashcards
1
Q
What are the two biggest factors associated with development of osteoporosis?
A
- Elderly age
- Menopause/post-menopause
2
Q
What hormonal changes are characteristic of osteoporosis?
A
- ↑ PTH
- ↓ Vit D
- ↓ HGH
- ↓ Insulin-like growth factors
I Prefer High D’s
3
Q
What are the four most common meds used to treat osteoporosis?
A
dronate drugs - Biphosphate drugs that inhibit osteoclasts:
- Actonel (Risedronate)
- Boniva (Ibandronic Acid)
- Fosamax (Alendronate)
- Reclast (Zoledronate)
4
Q
Differentiate between Bouchard’s nodes and Heberden’s nodes.
A
- Bouchard’s = proximal interphalangeal joints
- Heberden’s = distal interphalangeal joints
5
Q
Medical management for Osteoarthritis
A
- NSAIDS: meloxicam
- COX2 inhibitor: celebrex
- Topical treatment (voltarin is now a over the counter drug)
- Intra-articular therpy (steroid injection)
- Chondroprotective agents
6
Q
What drug is the most common chondroprotective agent that helps protect the articular joint?
A
Glucosamine
7
Q
What anesthetic considerations should be given to glucosamine?
A
- Stop 2 wks prior - platelet aggregation inhibition
Glucosamine needs to be stopped two weeks prior to surgery due to PLT aggregation inhibition.
8
Q
What arthritis is characterized by morning stiffness that improves throughout the day is….
A
Rheumatoid arthritis
9
Q
Arthritis that is characterized by worsening symptoms throughout the course of the day is…
A
Osteoarthritis
10
Q
What labs are typically elevated in a patient with rheumatoid arthritis?
A
- ↑ Rheumatoid factor (RF)
- ↑ Anti-immunoglobulin antibody
- ↑ C-reactive protein (CRP)
- ↑ Erythrocyte Sedimentation Rate (ESR)
C? Reggie Acts Entitled
11
Q
What common dose of stress dose glucocorticoid is used for RA patients?
A
50 - 100mg hydrocortisone (Solu-cortef) or dexamethasone
12
Q
What two TNFα inhibitors are commonly used to treat RA?
A
- Etanercept
- Infliximab
13
Q
Which of the following drugs treat RA?
- Methotrexate - antimetabolite - decreases immune response
- Hydroxychloroquine - antimalarial - decreases immune response
- Sulfasalazine - Anti-inflammatory - decreases immune response
- Leflunomide - disease modifying anti-rheumatic drug (DMARD) - inhibits mitochondrial enzyme dihydrorotate dehydrogenase.
A
Trick question. All of them do
- Methotrexate
- Hydroxychloroquine
- Sulfasalazine
- Leflunomide
14
Q
What airway concerns should be considered with RA patients?
A
- Limited TMJ movement
- Narrowed glottic opening
- Cricoarytenoid arthritis
15
Q
Where is the most instability typically located in the cervical spine of RA patients?
A
Atlantoaxial Junction
(be careful not to displace the odontoid process i.e the dens and impinge on the c-spine or vertebral arteries)
16
Q
What are the signs and symptoms of atlantoaxial subluxation?
A
- Headache
- Neck pain
- Extremity paresthesias (especially with movement)
- Bowel/bladder dysfunction
NHEBs
17
Q
What are the signs/symptoms of vertebral artery occlusion?
Think neurological symptoms seen in neuro ICU
A
- Transient LOC changes
- N/V
- Blurred Vision
- Dysphagia
Naked Dicks Be Loose
18
Q
What ocular syndrome is typical of RA patients?
A
Sjogren’s syndrome
(Dry eyes and mouth)
(show-grins)
19
Q
What pulmonary issues are associated with RA?
A
- Interstitial fibrosis
- Restricted ventilation
20
Q
Additional anesthesia concerns for RA:
- vascular
- cardiac
- GI
- Renal
A
- Vasculiltis
- Pericarditis or cardiac tamponade
- Gastric ulcers
- Renal insufficiency
21
Q
Preop eval for RA
A
- Joint involvement
- Baseline pain level
- Neuro assessment (where is the numbeness and tingling)
- Surgical positioning and mobility
- Type of anesthetic (regional and pt comfort, ability to remain still for procedure, post ROM)
always establish the baseline in preop
22
Q
What type of ventilatory settings would be utilized for an RA patient exhibiting a restrictive ventilatory pattern?
A
Pressure Control @ 5mL/kg
23
Q
What artery is typically injured due to pelvic fractures? Where is the bleeding located in this instance?
A
Iliac artery → retroperitoneal space bleeding
24
Q
What is the typical worst complication of long bone fractures?
A
Bone marrow fat embolism
25
What technique is used for intubation of a patient who has c-spine concerns?
MILS
Manual In-Line Stabilization
26
ABCD's of trauma anesthesia (how to do a trauma RSI)
- MILS
- preoxygenate (100% 10-15L/min for 3 mins minimum) **can preoxygenate before putting on monitors in this case**
- cricoid pressure *sellick maneuver/BURP* (10lbs of pressure
- induction with medications (ketamine or etomidate then muscle relaxation)
- apenic ventilation (careful with modified RSI)
- DL or LMA after 3 attempts
27
Describe the MILS technique
28
What is the mechanism of action of warfarin?
Warfarin inhibits **Vitamin K epoxide reductase** and limits the availability of Vitamin K throughout the body
29
What is the mechanism of action of LMWH?
LMWH binds and activates antithrombin thus → no thrombin → no fibrinogen forming into fibrin
30
What are some typical triggers for delirium?
- Sleep depravation/circadia rhythm disruption
- Infection
- Electrolyte abnormalities
- Pain
- Benzos (Castillo says debatable)
- Anticholinergics
- Hypoxemia
- Hypotension
- Hypercarbia
- Hypervolemia
31
Pre-op eval of lungs
- age related:
- decreased PaO2
- decreased FEV1
- increased closing capacity volumes
- Obesity
- OSA (stop-bang questionnaire)
- Snore
- Tired
- Observed (to stop breathing)
- Pressure (high pressure treatment)
- BMI (>35)
- Age (>60)
- Neck (circumference >17 in)
- Gender (M)
32
FEV₁ decreases by ___% for each decade of life.
10%
33
What occurs with closing volume as we age?
Closing volume **increases**.
34
What is the goal of regional anesthesia vs general anesthesia?
To avoid:
- DVT & PE
- EBL
- Respiratory complications
- Death
35
With placement of what device is fat embolism syndrome most likely to occur?
Femoral Medullary Canal Rod (IM nail/rod)
36
What is the s/s Triad of fat embolism syndrome?
How soon do s/s typically present?
1. Confusion
2. Dyspnea
3. Petechiae
**Typically presents in 12 - 72 hrs**
C? Dis Persnickety
37
What lab findings are noted with fat embolism syndrome?
- ↑ESR
- Fat macroglobulinemia
- Anemia
- Thrombocytopenia
Ees FAT
38
Elevated ESR may be a finding in fat embolism syndrome (FES)
What is ESR? What are normal values for males and females?
- Erythrocyte Sedimentation Rate
- Male: 0 - 22 mm/hr
- Female: 0 - 29 mm/hr
39
What minor s/s can be construed to characterize fat embolization syndrome?
- Fever
- ↑HR
- Jaundice
- Renal Changes
Jill Has Fewer Rashes
40
What are the anesthetic management techniques for fat embolization syndrome?
Supportive Therapy **early recognition**
-
- stabilization of fracture
- 100% FiO₂
- IV Heparin
- Aggressive and early CV & Resp support (could pregress to ARDS yikes)
- **No N₂O**
41
What factors contribute to the development of DVT's?
- **Lack of Prophylaxis**
- Obesity
- > 60yrs old
- > 30min procedure
- Tourniquet use
- > 4 days immobilization
- > Lower extremity fracture
42
Which three surgery types present the greatest risk for DVT formation?
- Hip surgery
- Knee - TKA
- Lower extremity - trauma
43
When does LMWH need to be initiated for DVT & PE prophylaxis?
12 hours preop
or
12 hours postop
| Castillo hinted this would be on the test
44
Can neuraxial anesthesia be done after LMWH has been given?
Yes, if **10 - 12 hours** after the dose.
*Delay next dose 4 hours and remove catheter 2+ hours before next dose*
45
Can an epidural be placed in a patient on LMWH anticoagulation therapy?
No. No indwelling catheters
46
Neuraxial catheters must be removed ___ hours before the intiation of LMWH therapy.
2 hours
47
Can a patient have neuraxial anesthesia if on warfarin?
Only if the **INR is ≤ 1.5**
## Footnote
>1.5 clotting time is longer than normal - ↑ risk of bleeding
48
Flip card for Anticoagulation guidelines for Neuraxial procedures.
49
Flip card for additional Anticoagulation guidelines for Neuraxial procedures.
50
What advantages does neuraxial anesthesia present in the prevention of DVT's?
- Anti-inflammatory properties of LA
- ↑ extremity venous blood flow (sympathectomy).
- ↓ PLT reactivity
51
What is the maximum dose of TXA? (Tranexamic Acid)
2.5 g
52
What is typical dosing of TXA?
10 - 30 mg/kg
**1000mg is typical**
## Footnote
adminstered before incision (think about single dose vs repeated dose)
53
Tourniquet pain typically begins ___ minutes after application.
45 min
54
The width of a tourniquet must be greater than ____ its diameter.
½
## Footnote
apply over padding and exanguinate the limb before inflation
55
How long can tourniquets be placed on an extremity?
- 2 hours is typically not exceeded
- **3 hours is max**.
56
What mmHg is typically used for thigh tourniquets?
300 mmHg
(or 100 mmHg > SBP)
57
What mmHg is typically used for arm tourniquets?
250 mmHg
(or 50 mmHg > SBP)
58
When utilizing a double tourniquet, it is important to remember to...
inflate proximal cuff first → deflate distal cuff first
Primero Proximao
Duo distal
59
What occurs with tourniquet deflation?
- ↓ CVP, BP, & temp
- ↑ HR
- ↓ pain
- Transient lactic acidosis
- Transient Hypercarbia (thus increase V̇T)
**H**yper **LA** **H**ides **P**anicked **B**al**T**i**C**s
60
# Lecture 2 start
What are some important points of assessment necessary for upper body procedures preoperatively?
- Baseline vitals
- Airway
- Pre-existing nerve conduction issues
- Examine pupils
BAPP
61
What are the cardiac consequences of sitting/Beach Chair position?
- ↓ BP & CO
- ↑ HR & SVR
Due to pooling of blood in lower body.
62
What are the respiratory consequences of sitting/Beach Chair position?
- ↑ FRC & lung volumes
63
What are the neurologic consequences of sitting/Beach Chair position?
↓ CBF
64
How is venous air embolism prevented in a beach chair patient?
↑ CVP (above 0) to prevent a "suction" effect
## Footnote
If the surgical site is higher than the heart, its possible to entrain air into the open vessels and cause an air embolism
65
Treatment for Venous air embolism
- Tell surgeon so they prevent further entraning of air by irrigating or applying an occlusive dressing
- D/C N2O
- Bilateral compression of jugular veins
- Tburg position (head down) to trap air in R atrial apex (prevents entrance to pulm. art.
- withdraw air from central line if its already there (dont place a new one)
- Pressors w/ CV collapse
66
The doppler US transducer can be used to indicate a VAE in a sitting pt, where do you place the probe on the chest?
- over RA
at the 2nd or 3rd intercostal space to the right of the sternum (most sensative non-invasive indicator of VAE)
| Most **definative** is still a TEE
67
What is the characteristic sound of a VAE, and most characteristic monitor change?
- sound = **mill-wheel** murmur
- Monitor change = sudden decrease in EtCO2 (decreased perfusion to lungs)
68
In what percent of the population is a patent foramen ovale present?
20 - 30 %
69
____ of the neck in a sitting position patient can accidentally extubate them.
Hyperextension
70
In a sitting position patient, where would one zero their art line?
Tragus of the ear
*Establishes knowledge of brain BP & thus perfusion*.
| **this is at the level of that damn Willis Suurkle**
71
Sometimes the hammer-dudes want us to lower the BP so they can see the surgical site better, what are ocular conditions do we want to avoid due to the hypotension inherent to the sitting position?
- Retinal Ischemia
- Ischemia Optic Neuropathy
*Also avoid corneal abrasion*.
72
There is a 40cm distance from the patients heart to their brain. The patient's BP measured on the arm is 120/70. What is the estimated BP in the brain?
**Castillo's way**: 40cm x 0.77mmHg = 30.8mmHg
120 - 30.8 = 89.2mmHg
70 - 30.8 = 39.2mmHg
The patient's brain BP is **89/39** Thus indicating hypotension and necessary correction.
**Easier way**: just remember **7.410pH** i.e. for every 10cm change from the heart, the pressure changed by 7.4mmHg
40cm away = 4 x 7.4 = 29.6
120-29.6 ~90
70-29.6 ~ 40
73
A standing patient's NIBP on the arm is 134/92. The distance between the patient's knee and the NIBP cuff is 120cm. What is the BP in the patient's knee?
120 x 0.77 = 92.4
134 + 92
92 + 92
Patient's "knee" BP standing up is 226/184
74
What is the Bezold-Jarisch reflex?
Bezold–Jarisch reflex is an alternate explanation for the bradycardia that often accompanies hypotension after neuraxial anesthesia
Cardiac inhibitory reflex resulting in signification HoTN & ↓HR.
## Footnote
The Bezold–Jarisch reflex is an alternate explanation for the bradycardia that often accompanies hypotension after neuraxial anesthesia. This reflex is mediated by 5HT-3 serotonin receptors located in the vagus nerve and in ventricular myocardium. Activation of these receptors in response to systemic
hypotension **increases efferent vagal signaling, producing bradycardia, reduced cardiac output, and worsened hypotension.**
Several groups have studied the effects of HT-3 receptor antagonists like ondansetron on the hemodynamic effects of neuraxial anesthesia. Meta-analysis of these results suggests that ondansetron may halve the risk of subarachnoid anesthesia-induced hypotension
75
How do we avoid the Benzold-Jarisch?
Increase preload and give zofran upfront
76
What are possible complications of a brachial plexus block?
- Respiratory depression (phrenic nerve compromise)
- Horner Syndrome
- Hoarseness
- Dysphagia
Reggie Horner, Horse Doctor
77
Why can respiratory depression occur with brachial plexus blocks?
Hemidiaphragmatic Paresis from Phrenic nerve blockade.
78
What is the triad of Horner Syndrome?
- Ptosis
- Miosis
- Anhydrosis
79
What are the respiratory consequences of a lateral decubitus position?
(VQ mismatch)
- ↓ ventilation of **dependent** lung.
- ↑ perfusion of **dependent lung**.
80
During mechanical ventilation in left lateral decubitus patient, which lung is overventilated?
Right lung (nondependent lung)
81
During mechanical ventilation in left lateral decubitus patient, which lung more perfused?
Left lung (dependent lung)
82
Where is an axillary roll placed on a lateral decubitus patient?
Caudad to the axilla to avoid compression of the neurovascular bundle. (Displaces the humeral head away from the brachial plexus)
83
Where should a pulse oximeter be placed in a lateral decubitus patient?
Dependent hand to ensure that there is no neurovascular compromise
84
Elbow surgeries need what additional block (in comparison to shoulder surgeries) ?
Musculocutaneous nerve
85
Is a patient with a hip fracture induced on the OR table or on the bed/stretcher?
Bed/Stretcher to avoid pain from movement to OR table.
86
What are the benefits of neuraxial anesthesia for hip fracture repairs?
- Better pain control
- ↓ DVT
- ↓ hospital stay
- ↓ delirium
87
What are the three life-threatening complications of total hip arthroplasty?
- BCIS (bone cement implantation syndrome)
- Hemorrhage
- VTE
88
What chemical is bone cement?
PolyMethylMethAcrylate
89
What does bone cement do when introduced to the intramedullary bone surface?
Release heat and pressurize (500mmHg!)
Possible embolization of fat, bone marrow, and cement.
90
What is the anesthetic management of BCIS?
- Combat ↓BP and ↓Volume
- ↑ FiO₂ & SpO₂
91
What are the s/s of BCIS?
- **Hypoxia**
- **Hypotension**
- Arrythmias
- pHTN
- ↓CO
Hi Hi CO And Puffs
92
In a supine position, spontaneous ventilation favors ____ lung segments, whilst closing volume favors ____ lung segments.
Dependent ; independent
93
The most common postoperative peripheral neuropathy is:
a. Ulnar neuropathy
b. Brachial plexus injury
c. Median nerve injury
d. Sciatic nerve compression
a. Ulnar Neuropathy
94
Where are the two major sites of injury in ulnar nerve injury?
Elbow at the **condylar groove** and **cubital tunnel**.
95
How is ulnar nerve nerve injury avoided?
Supinate hands (palms up!)
96
What common drugs are often used for "conscious sedation" of a hip dislocation?
Ketamine/Propofol Mix
Succinylcholine
97
What are the possible complications of tourniquet placement for knee surgeries?
- Blood loss on deflation (note for 24hrs)
- Peroneal Nerve Palsy
98
What are the steps to a TKA (Total Knee Arthroplasty) ?
1. Tibial Component
2. Femoral Component
3. Patellar Component
4. Plastic Spacer
99
What three conditions (that anesthesia can control) are most often associated with infection of knee replacements?
- Peri-operative glucose control
- Post-op hypoxia
- Post-op hypothermia
100
What medication classes can be used to treat phantom pain from amputation?
- Neuroleptics
- Antidepressants
- Na⁺ channel blockers
101
What nerve innervates the plantar surface?
Posterior Tibial nerve
102
What nerve innervates the medial malleolus?
Saphenous nerve
103
What nerve innervates the interspace between the great & 2ⁿᵈ toes?
Deep Peroneal nerve
104
What nerve innervates the space between the dorsum of the foot and the 2ⁿᵈ - 5th toes?
Superficial peroneal nerve
105
What nerve innervates the lateral foot and lateral 5th toe?
Sural nerve
106
Antifibrinolytic Therapy Concerns: TXA
Major Concerns with TXA:
1. Venous Thromboembolism (VTE) (DVT/PE)
* Theoretical concern due to its antifibrinolytic action, but clinical studies do not show a significant increase in VTE risk when used in surgical or trauma settings.
* However, caution is advised in patients with a history of VTE or those at high risk.
2. Myocardial Infarction (MI)
* No strong evidence linking TXA to an increased risk of MI, but it may promote clot stability in coronary arteries, potentially worsening an existing thrombus.
* Caution in patients with active coronary artery disease (CAD).
3. Cerebrovascular Accident (CVA/Stroke)
* There is a small risk of ischemic stroke in patients with pre-existing cerebrovascular disease or prothrombotic conditions.
* TXA should be used cautiously in patients with a history of stroke or TIA.
4. Transient Ischemic Attack (TIA)
* Similar to stroke concerns, TXA could theoretically increase clot persistence in cerebral circulation.
* Clinical relevance remains unclear, but caution is advised in high-risk individuals.
Other Concerns:
* Seizures: Increased risk at high doses due to inhibition of GABA receptors. This is seen in cardiac surgery and neurosurgical settings.
* Renal Impairment: TXA is renally excreted, requiring dose adjustments in kidney disease.
* Hypotension: Rapid IV administration can cause hypotension; it should be given slowly over 10 minutes.
Clinical Takeaway:
* TXA is generally safe, but patients with a history of VTE, MI, stroke, or TIA should be evaluated carefully before use.
* Low doses and short duration reduce thrombotic risks.
* Monitor for seizures in high-dose settings (e.g., cardiac surgery).
* Use cautiously in patients with renal impairment to prevent accumulation.
107
What are some additional negative physiologic effects s/p tourniquet deflation?
- Metabolic Acidosis
- Hyperkalemia
- Hypercarbia
- Tachycardia
- Hypotension
