Orthopedic Flashcards
What 3 things happen to bone cement that lead to intermedullary hypertension?
- Heat
- Expansion
- Hardening
Intermedllary hypertension leads to what 4 things moving where?
- Fat emboli
- bone marrow
- cement
- air
- Into the femoral venous channel
Residual mma monomer can do what 2 things?
- Vasodilation
- Decrease SVR
Bone cement can cause tissue thromboplastin release, what 3 things does tissue thromboplastin cause?
- Platelet aggregration
- Microthrombus in lungs
- CV instability
What are the 6 problems associated with bone cement syndrome?
- Hypoxia
- Hypotension
- Dysrhythmias
- Decreased CO
- Pulmonary HTN
- Embolization
6 problems with pneumatic tourniquets.
- Hemodynamic changes
- Pain
- Metabolic changes
- Thrombus
- Muscle/nerve injury
- Limb cooling
Prolonged cuff time of 45 - 60 minutes leads to what?
- HTN
- Tachycardia
- Sympathetic stimulation
Cuff deflation drops what 3 things?
- CVP
- MAP
- Temp
Cuff pressure should be what? and what are the limits?
- 100 torr above systolic pressure
- Upper extremity = 250
- Lower extremity = 350
Tourniquet pain is caused by what type of fibers? and feels like what?
- Slow, unmylenated C fibers
- Aching and burning
What is will you see when the cuff is deflated?
- Increase in end tidal CO2
- lactate
- Potassium
- Increase in minute volume
- Possible dysrhythmias
Reperfusion injuries can happen from what?
-Free radical formation
Tourniquets are contraindicated in what?
-Calcified arteries
Prolonged tourniquet time of greater than 2 hours leads to what injuries?
- Muscular
- Nerve
- Rhabdo
When does fat embolism syndrome occur? and what are the triad of symptoms?
- w/i 72 hours of long bone or pelvic fx
- Dyspnea
- Confusion
- Petechiae
Where else can fat embolism syndrome be seen?
- CPR
- Liposuction
- IV lipids
Where does fat emboli enter circulation?
-Tears in medullary vessel
Fat embolism syndrome releases amines and prostaglandins that can cause what 3 things?
- ARDS
- Cerebral capillary damage
- Edema
How does fat embolism syndrome effect coagulation?
- Throbcytopenia
- Increased clotting time
Where are petechiae found during fat embolism syndrome?
- Chest
- Upper extremities
- Conjunctiva
Where are fat globules seen fat embolism syndrome?
- Retina
- Urine
- Sputum
Fat embolism respiratory concerns.
- Anywhere from mild hypoxia to ARDS
- Decrease in ETCO2 and SPO2
- Increase in PAP
Risk factors for DVT / PE in ortho?
- > 60 yo
- Obesity
- Tourniquet
- Procedure >30 min
- lower extremity fx
- Immobilization > 4 days
What procedures are at highest risk for DVT / PE?
-Knee and Hip replacment
What is the pathogensis of DVT and PE?
-Venous stasis and hypercoagulability from inflammation
How does neuraxial anesthesia help in reduce DVT and PE?
- Increase in venous blood flow
- Antiinflammatory effects
- Decreased platelet activity
- Less stress hormone
Placement or removal of an epidural needle or catheter should not be undertaken within ____ of a SQ minidose of heparin or with _____ of LMWH
- 6-8 hours
- 12-24 hours
Hallmarks of hematoma?
- Back pain
- Lower extremity weakness
- Incontinence
_____and ______ that limit ROM of a joint may require anesthesia for manipulation to occur
- Scars
- Adhesions
What allows surgeons to distinguish between anatomical limitations and patient guarding.
-Profound relaxation
What things may be needed in a close reduction
- Pins
- Xray/Fluoro
- Cast / splint
With hip fx, need to determine the cause of the fall prior to surgery. Common reasons are?
- Accident
- Neuro event
- C/V event
- Dementia
- Dehydration
Hip fx mortality is ____ during hospitalization and ____ during the 1st year.
- 10%
- 25%
Name 2 reasons to delay hip surgery.
- Coaglopathy
- Uncompensated heart failure
Hip surgery consderations
- Surgery w/i 48 hours
- Type and cross
- Check hypoxia
5 predictors of hip fx mortality
- > 85 yo
- Hx of CA
- Neuro decline
- Chest infection (pneumonia)
- Wound infection
Benefits of regional in hip surgery.
- Decreased blood loss
- Reduced DVT/PE
- Faster return to baseline neuro
- Hypobaric technique
How can you lose benefit regional?
- Oversedation
- Hypoxia
After ______ months there is no difference in mortality between regional and general.
-2 months
Blood loss from hip fx depends on what? and in what order?
-Location of fx
-subtrochanteric,intertrochanteric >
base of femoral neck>
transcervical, subcapital
When would you use general anesthesia with hip fracture? And what should be used?
- Bigger fx = longer surgery
- Short acting drugs
- Lower soluble agents
How can you minimize post op cognitive impairment?
- Minimal use of versed
- maintain O2
- Maintain hgb
- Maintain normal capnea
What is an arthroscopy? What are the benefits of arthroscopy?
- Examine interior joint w/ endoscope
- Less EBL, Pain, Rehab
What can be done with and arthroscopy?
- Definitive diagnosis
- Menisectomy
- Loose body removal
- Cruciate ligament repair
What drug is helpful for arthroscopic procedures?
-Ketorolac
Goals of Total hip
- Pain relief
- Correct deformity
- Joint stability
Total hip indications
- Osteoarthritis
- Rheumatoid arthritis
- Vascular necrosis
What is Rheumatoid arthritis?
-Immune mediated joint destruction w/ synovial inflamation
What can cause RA and where else can it be found?
- Use of steroids, antiinflammatories, methotrexate
- Atlantoaxis (c1/2) and TMJ
What causes vascular necrosis?
- Injury
- Drug abuse
When is and embolic event most frequent?
-Insertion of femoral componet
How much blood loss can you expect with a total hip? Hip Revision?
- 400-1500
- 2000
Knee blood loss vs Hip blood loss?
-Knee has less intraop blood loss (100-200) but greater overall blood loss post op.
What procedure has the highest rate of DVT among all ortho procedures?
-Total knee
Upper extremity surgery considerations.
- Sitting or Lat decub position
- Interscalene block
- Maintain BP
- No tourniquet / blood loss
- Pneumothorax
- Subclavian vein injury
- Extubation
- Venous air embolism
Anesthesia considerations for foot and ankle surgery?
- Regional
- Nerve block w/ sedation
- Use of tourniquet
- LMA
- Local injection for post op pain
Amputations concerns?
- Psychological trauma
- Phantom limb pain
How would you maintain blood flow in a limb re-implantation?
- Optimal HCT 28-30%
- Keep warm
- Avoid vasoconstrictors
- Dextran or heparin infusion
Shoulder needs what type of block?
-Interscalene
Problems with interscalene blocks?
- Pneumothorax
- 100% phrenic nerve block
- Horner’s
- Hoarsness
- Decreased chest wall sensation
