Circulatory Arrest
Last modified: 15 November 2021, 7:11:37 PM AEDT
- Deep Hypothermic Circulatory Arrest
Gems1 / 6
- brain injury occurs at 4 mins of CA at normothermia
- cerebral metabolism decreases 6-7% for every 1°C decrease in temp from 37°C
Definition2 / 6
- cooling to 18-20°C
Indications3 / 6
- cerebral and organ protection
- ⬇MRO2 / ⬇demand (to offset ⬇perfusion / ⬇supply)
- brain is most susceptible to ischaemia during CA, so other organs will also be protected
- Aortic arch surgery
- when not possible to perfuse cerebral vessels on bypass
- cardiac surgery
- aortic arch reconstruction
- pulmonary TEA
- non-cardiac surgery
- repair giant cerebral aneurysms
- cerebral AVM
- RCC with IVC invasion
Risks / disadvantages4 / 6
- C = cardiac
- arrhythmias
- D = neurological / cerebral
- vasoC during cooling
- PNCD (postop NCD)
- proportional to DHCA time
- injury also from prolonged CPB and rewarming
- 30 mins = safe
- 60 mins = most patients will suffer irreversible brain injury
- F = renal and metabolic
- metabolic acidosis
- H = coagulation
Technique / description5 / 6
- ACT
- UFH 3-5 mg/kg for ACT > 400 sec
- cooling during CPB
- heat exchanger in CPB oxygenator
- temperature gradient < 10°C
- selective anterograde cerebral perfusion = SACP
- R+/-L carotid As are perfused with cannulae in CCA
- retrograde cerebral perfusion = RCP
- cold oxygenated blood is directed into SVC via A-V CPB shunt