3 types of blood borne emboli:
- Cellular aggregates
- Lipids
- Fibrin
3 types of Foreign Material emboli:
- Cotton Fibers
- Plastic particles
- metal particles
3 types of Gaseous emboli:
- Micro gaseous GMEs
- Visible air embolism
- Gross air embolism
Out of the 284 incidents of air embolism during CPB,
which 2 has the highest occurrence?
Which has the lowest occurrence ?
Highest=
- Inattention to reservoir level 104 (37%)
- Ao root air during CPS admin 82 (29%)
Lowest =
- Pressurized cardiotomy: 15 (5%)
- Ruptured raceway tubing 16 (5%)
- Unnoticed rotation of arterial pumphead 14 (5%)
What was the rate of air emboli occurrence as a result of a reversed LV vent line ?
26 (9%)
What was the rate of air emboli occurrence as a result of an unexpected heart beat?
27 (10%)
What are the 5 CPB air emboli safety devices?
- Level Detector
- Bubble detector
- One way valves
- Purge lines
- Vent lines
What is the treatment for massive air embolism, which leads to a critical complication due to neurologic damage ?
Retrograde cerebral perfusion
Name 5 causes for massive air emboli ?
- Sudden reduction in venous reservoir level due to large Aortopulmonary collaterals.
- Inversion of left sided vent
- Reversal of pump head
- Air from cardiac chambers
- Runaway pump head
How would you manage a massive air embolism?
- Stop CPB immediately
- Clamp venous line
- Steep trendelenburg
- Remove aortic cannula
- Clamp out ALF if filled with air
- De-air arterial cannulae & pump line
- Retrograde hypothermic SVC perfusion
30 - 40 mmHg - Resume antegrade CPB
- 100% FiO2
- Rewarm to 34 °c , no overheating
- Induce hypertension
What are the parameters for Retrograde cerebral perfusion ?
Pressure:
Flow:
Temp:
Duration:
Pressure: 30 - 40 mmHg
Flow: 1 - 2 L/m
Temp: 20 - 24 °c
Duration: 1 - 4 min
Compression of carotid
Confirm no air in Ao cannulation site
What are the 3 cerebroprotectants administered in the O.R. for treatment of massive cerebral embolism ?
- Methylprednisolone 30 mg/Kg
- Mannitol 1gm/kg
- Thiopental 20 mg/Kg
What are the 3 cerebroprotectants administered in the ICU for treatment of massive cerebral embolism ?
- Methylprednisolone 30 mg/Kg
- Mannitol 0.5 gm/kg Q 8hrs
- Phenytoin 25 mg Q 12hrs
What is the temperature control for managing a massive cerebral emboli ?
Retrograde cerebral perfusion at 20 - 24°c for 1 - 4 min.
Do not rewarm completely! Rewarm to
33 - 34 °c.
What are the perfusionist responsibilities during a cerebral air embolism incident ?
- Off CPB, clamp Venous and Arterial
- Identify problem
- Reprime circuit and Ao cannula
- Retrograde SVC perfusion 1 - 2 L/m
- Reinstitute CPB @ 22-30°c, ^ systemic pressures
- FiO2 @ 100%
- Off bypass @ 34°c
What are the Surgical responsibilities during a cerebral air embolism incident ?
- Clamp and remove Ao cannula
- Cannulate SVC or connect to SVC cannula
- Retrieve blood/air exiting the Ao via vent.
- When no more air is visible at aortonomy, recannulate the Ao and reinstitute bypass.
- Bleed air from the coronaries
- Complete surgical procedure
What are the Surgical responsibilities during a cerebral air embolism incident ?
- Steep T-burg
- Compress carotid arteries
- Consider administering:
Steroids
Mannitol
Antiplatelet agents
Barbituates
Post bypass management of a cerebral air embolism ?
- Ventilate with 100% FiO2
- Slight hyperventilation
- Rewarm to normothermia over 24hrs
- Reverse T-Burg
- Avoid hyperglycemia & hyponatraemia
- Consider hyperbariac oxugen treatment
What are the basic principles of management of massive air embolism during CPB ?
- Make the diagnosis
- Communicate the diagnosis
- Prevent further embolism
- Identify the source of air embolism
- Limit organ damage
- Clear the CPB circuit of air
- Re-establish circulation
Name 5 neuroprotectants used after cerebral air embolism ?
- Corticosteroids
- Antioxidants
- Free radical scavengers
- General anesthetic agents
- Local anesthetics
Perhaps retrograde cerebral perfusion is not as good as we think. Increased venous cerebral perfusion pressure is associated with destruction of the blood-brain barrier. What are the pressures suggested that will create the maximum retrograde cerebral flow with the least chance of producing increased ICP ?
20 - 25 mmHg
What were the results of cerebral perfusion using india ink on the 10 pigs ?
Antegrade pigs intracranial artery and vnous system is completely filled with ink
Retrograde pigs - 10% of the cappilaries are filled with ink
