In 2006...

_____ of pop. over age 65

_______ hip replacements

______ knee replacements

By 2030 number of ppl over 65 expected to ___?

In 2006...

1/8 of population over age 65

300,000 hip replacements

500,000 knee replacements

By 2030 number of ppl over 65 expected to double 

Comorbidities

Limited functional capacity in many elderly

Many orthopedic procedures initiate a significant systemic inflammatory response

Potential for significant blood loss & fluid shifts

Difficulty in postop pain management

Cardiac

Pulmonary

Neurologic

Is embolism of fat common?

It is found in almost 100% of _____ and _____ fractures.

How does FES develop?

Does the quantity of fat correlate with severity of symptoms?

may develop gradually or acutely

no, quantity of fat in circulation doesn't correlate with severity of symptoms

mechanical obstruction of end-organ capillaries

trigger of systemic inflammatory response

petechial rash

diffuse alveloar infiltrates

hypoxemia (PaO2 <70 on 100% O2)

confusion

fever >38C

heart rate >120/min

respiratory rate >30/min

Gurd's Diagnosis of Fat Embolism Syndrome:

Major Features (at least one)

List 3

Minor Features (at least four)

List 5

Lab findings

List 4

What have multiple studies shown that RA has what benefits over GA with hip arthroplasty?

RA has following benefits over GA:

↓Blood Loss

↓ DVT

↓ PE 

There is a _____ greater incidence of DVT with GETA over a RA.

The greatest risk of death following THA is d/t ______?

Besides the decreased BL & decreased risk for DVT or PE is there any other compelling differences between outcomes with regional & GETA?

There is a 4x greater incidence of DVT with GETA over a RA.

Greatest risk of death following THA is d/t PE

with the exception of pain management, there is no othercompelling difference between outcomes with RA and GETA

cancer

obesity

previous PE/DVT

prolonged bed rest (r/t pain mngmt)

advanced age

COPPA

What is the timing of neuraxial blocks with LMWH?

Usual dose?

Large dose?

What about removal of epidural catheter?

12 hrs after usual dose

24 hrs after larger dose (enoxaparin 1mg/kg)

epidural cath removed 8-12 hrs after and 1-2 hrs before next dose of LMWH

What population are hip fractures common in?

1 year mortality for pts with hip fxs?

Highest risk of death with hip fracture is from _____?

common in elderly patients

1 out of 50 (pts over age 60)

1 year mortality ~30% 

highest risk of death is from PE

With hip fractures, what type of anesthesia is advantageous?

Early surgery (within ___ hrs of injury) help reduce 3 things, what are they?

Though there is NO change in overall ______ with early surgery?

RA advantageous

12hrs 

Early Surgery

↓ Pain scores

↓ Length of hospital stay

↓ Periop complications

no change in overall mortality

Pelvic fractures are usually caused by significant _______ and are associated with other _______?

What other injuries are common? (3)

significant trauma

other injuries

Chest 21%

Head 16%

Liver & Spleen 8% 

What is the 3 month mortality rate with a pelvic fracture?

What is a major issue that may be see with a pelvic fracture?

When may repair/stabilization be done?

~14%

pts may have extensive retroperitoneal bleeding

may be done in combination with other procedures, or at least stabilization of other injuries

(best to do it within a week of injury but not always possible with other injuries that take priority per Miller)

Awake fiberoptic

-may consider positioning awake following intubation with confirmation of movement of extremities prior to induction

In-line traction with minimal movement of neck

-appropriate when C-spine has been radiologically cleared or when loss of life is imminent

thoraco-lumbar

Consider pros and cons of:

Normovolemic hemodilution

Deliberate hypotension

Staging of the surgery

What is critical with thoraco-lumbar spinal surgery?

What monitoring techniques can be used?

positioning & ongoing monitoring of position is critical

use of other monitoring techniques - eg. evoked potentials, wake-up test

When is the wake-up test most commonly used?

Why?

most commonly used when repairing deformity

ie scoliosis kyphosis

straightening (distraction) of the spine can impair blood flow to anterior cord

Why should the wake-up test be discussed with the pt preop?

What does the wake-up test require?

recall unlikely, but certainly possible

requires careful planning

Steps for wake up test:

1. VIA discontinued well before test planned

2. NMB doses titrated to achieve 2-3 twitches

(do not fully reverse NMB)

3. Discontinue nitrous

4. Begin asking pt to wiggle their toes 

(be patient, this may take a few minutes for them to get light enough)

5. When surgeon is satisfied, re-deepen the anesthetic (be sure another wake up wont be needed too soon)

What issues can placement of bone cement be associated with? Why?

What can you do prior to placement to prevent this issue? (4)

occasionally associated with sudden hypotension multiple mechanisms postulated

What you can do prior to placement:

ensure adequate fluid status

don't deepen anesthetic just before placement

maximize oxygenation

DC N2O before placement

~100mmHg > systolic BP for thigh

~50mmHg > systolic BP for arm

What is the acceptable duration of inflation?

What must be done when this time period is up?

there is controversy but...

typically 1-2 hrs is considered acceptable

after this time there should be a 5 minute period of perfusion, then re-exsanguination & inflation

Record inflation/deflation times & inflation pressures

Notify the surgeon at 60 minutes and at least every 30 minutes after the initial 60 minutes

Document that surgeon has been notified

10-15% ↑ in HR

Slight increase in CO2 & serum K

only rarely do these present a problem

Potential release of emboli

How is tourniquet pain described and when does it occur?

What is the mechanism?

dull, aching pain, restlessness

occurs after about 45 minutes (sometimes)

mechanism unclear

RA - usual treatment = narcotics, hypnotics

GA = deepen anesthetic

With central retinal artery occlusion what area becomes ischemic?

Branch retinal artery occlusion?

CENTRAL - decreases blood supply to entire retina

BRANCH - affects only a portion of the retina

External compression of the eye

Decreased arterial supply to the retina

Impaired venous drainage of the retina

Arterial thrombosis

Embolic phenomenon

Hypotension

How common is embolic phenomenon?

When is it common?

rare in most surgical procedures

have been reports of paradoxical emoblism from surgical site

retinal microemboli common during open heart surgery

Hypotension (by itself) rarely seems to cause retinal ischemia

multicenter questionnaire revealed only 3 cases of retinal ischemia in 27,930 hypotensive anesthetics

What is imparied venous drainage from the eye due to?

Increased IOP is exacerbated by _______ and attenuated by ________ ?

studies on both normal and spine surgery pts show increased IOP in the prone position

-incr. in IOP exacerbated by head down position

-incr. in IOP attenuated by the head up position

How does the retina recieve blood supply?

What may increase IOP enough to decrease blood flow through both?

retinal blood supply is from the retinal and choroidal vessels

external compression, may increase IOP enough to decrease both retinal & choroidal blood flow

Irreversible

yep, you are blind forever

What is the treatment of retinal ischemia? (6)

*What is most important intervention?

Ocular massage to ↓IOP contraindicated if glaucoma not be ruled out

IV acetazolaminde may increase retinal blood flow

Inhalation of 5% CO2 in oxygen dilation

Thrombolysis by opthamologist

Localized hypothermia

Immediate opthalmology consult

present spontaneously

(only sometimes associated with surgery)

ION reported following:

Cardiothoracic surgery

Instrumented spinal fusion

Head and neck surgery

Nasal and sinus surgery

ION Signs & Symptoms (2 possible)

ION usually presents within ___ hrs or on _____.

Is ION usually unilateral or bilateral?

What about with spine surgery?

painless vision loss with no light perception

or

just visual field defects

usually presents within 24-48 hrs or often upon awakening

may be unilateral or bilateral

most post-spine surgery cases are bilateral

Blood Loss

Anemia or hemodilution

Altered venous hemodynamics

Abnormal autoregulation in optic nerve

Decreased blood pressure

Prone positioning

Use of vasopressors

Lengthy surgery for spinal fusion

Small cup-to-disc ratio

What is corticol blindness?

Does it result in complete blindness sometimes? Is it common?

bilateral visual loss

and

absence of lid reflex response to threat

yes - complete blindness implies infarction of both the right and left occipital cortex

this is rare

What is cortical blindness usually accompanied by?

*The majority (___%) of postop cortical blindness occurs with __________ or _________ surgery?

usually accompanied by signs of stroke in parieto-occipital area

~80% of postoperative cortical blindness occurs following cardiac or thoracic surgery

Ischemia

Cardiac arrest

Hypoxemia

Intracranial HTN

Hemorrhage

Vascular occlusion

Thrombosis

Intracranial hemorrhage

VasospasmEmboli

Prognosis - healthy pts may show significant recovery of vision, but course may be prolonged

Treatment - prevention of progression of stroke

T/F acute angle-closure glaucoma is common following anesthesia?

What population is acute angle-closure glaucoma most common in?

Symptoms? (2)

F - rare following anesthesia

most commonly in elderly women

symptoms:

painful red eye and cloudy or blurry vision

*Is acute angle-closure glaucoma related to anesthetic technique?

*Is acute angle-closure glaucoma a big problem?

No association made between acute glaucoma and anesthetic technique!

This is an emergency requiring immediate opthalmologic consultation

TURP

What type of cautery is used for a TURP?

What does the traditional method require to get rid of shavings?

unipolar cautery shaves slices off the prostate gland

requires use of irrigating fluid to distend the bladder & wash out shavings

TURP

How does absorption of irrigation fluid with a TURP effect the pt?

TURP

As the gland is resected in a TURP ____ _____ are opened & irrigating solution is _______?

What is this dependent on? (3)

As the gland is resected in a TURP venous sinuses are opened & irrigating solution  is absorbed

Dependent on:

# of sinuses opened 

 duration of procedure

Ht of irrigating solution

What pressure (ht) should be used for TURP?

What other surgery can cause similar fluid/electrolyte problems as the TURP?

<40 cm above pt

can see a similar problem w/ endometrial ablation when irrigating solution is used

-close record of I/O is kept in this procedure

Initially: excessive absorption of irrigant causes

HTN

Reflex bradycardia

baroreceptors

Pulmonary edema

3rd spacing 2ndry to hyponatremia & hypo-osmolality

hypotension - renal compromise

CV collapse

confusion

agitation

seizure

visual disturbance

pulmonary edema

CV collapse

What can TURP syndrome cause cerebrally? why?

Then the increased ICP causes reflex ______?

cerebral edema secondary to acute hypo-osmolality

increased ICP w/ subsequent reflex bradycardia

What is the treatment of hyponatremia with TURP syndrome in an asymptomatic patient?

Symptomatic?

Complication of treatment in symptomatic pt?

asymptomatic hyponatremic patient with near normal osmolality - none

symptomatic or hypo-osmolar hyponatremia - 3% saline

Complication: central pontine myelinolysis (demylination)

metabolic acidosis

and 

hyperammonemia

Transient blindness - glycine is an inhibitory transmitter in the retina

Encephalopathy and seizures - potentiation of NMDA, an excitatory transmitter

What laser is completely absorbed by water in the first few layers of cells; what nm?

What does this result in?

CO2 laser

10,600nm

results in explosive vaporization of surface tissue with little damage to underlying tissue

What do excimer lasers allow?

What type of surgery is this laser used in?

nm?

allow extremely precise focusing of ultraviolet light

used extensively in photorefractive surgery (lasix etc)

200-400nm

Describe the Nd:YAG laser...nm?

Types of surgeries (3)

less absorbed by water, therefore less vaporization and more thermal coagulation occurs (deeper "cooking" effects)

1064nm

TURP, laryngeal papilloma, laster uvulopalatoplasty

Vaporization of tissue by a laser produces a Laser plume; what is it?

In rats what has it done?

smoke and fine particulate matter produced by vaporization of tissue

in rats has produced: pneumonia, inflammation, and emphysema

What may the laser plume serve as?

Is there confirming data that viral transmission by a smoke plume is possible?

may serve as a vector for viral infection

 -have detected viral DNA in smoke plume from condyloma, and skin warts, but not laryngeal papilloma

No confirmation of viral transmission by a smoke plume has been shown

Which lasers produce the most smoke?

What is employed at the surgical site to get rid of the smoke?

CO2

smoke evacuator

Are ordinary OR masks ok with laser surgeries?

When do they need to be changed?

NO; ordinary OR masks don't filter small enough particles - special masks are required

need to be changed if damp b/c filtration becomes less effective

Vessel perforation

Tissue injury

Venous gas embolism

Wrong target

Airway fires

What size of vessels are not coagulable with laser?

What type of laser may produce more tissue injury?

vessels > 5mm

depth not well controlled with Nd:YAG

viable tissues

drapes

ETT

eyes

eyes taped

covered with opaque, saline soaked towel or metal shield

How can the OR personnel protect their eyes?

_______ to OR must be covered.  

Different lasers require different colored lenses

glass or plastic eyeglasses are adequate for CO2 lasers, but dont provide full coverage, WEAR THE GOGGLES.

Contact lenses provide no protection!

Windows to OR must be covered 

Minimize _____ to avoid an ETT fire when using a laser and use _____ instead? 

Is N2O flammable? Helium?

What other measure may help eliminate airway fires?

Minimize FiO2 - use AIR (has less O2)

N2O is flammable

Helium?

ETT protection

pledgetts covering cuff

wrapping tube with metallic tape

specialized coated tube and saline-filled cuff

metal ETT

1. Remove source (ETT, packing)
2. Stop ventilation
3. If airway fire continues, flood the field
4. Direct laryngoscopy/bronchoscopy to assess airway damage
5. Reintubation following bronchoscopy
6. Monitor for ≥24 hours
7. Consider steroids and antibiotics

Generate mass casualties

Would result in widespread M&M

Highly infectious and contagious

Inexpensive

No natural immunity

Easy large-scale dissemination

Easy to produce

GWHINEE