31 - 35 SBAs for the Final FRCA

31 - 35 SBAs for the Final FRCA
Photo by Unseen Studio / Unsplash

Question 31

A 54 year old man is about to be established on cardiopulmonary bypass for a CABG.

What is the correct target activated clotting time (ACT) to facilitate the bypass catheters?

  • 140 seconds
  • 280 seconds
  • 360 seconds
  • 480 seconds
  • 520 seconds


  • 480 seconds

This is just one of those numbers you need to memorise.

As one might expect, inserting large bore plastic tubing into the two most important blood vessels in the body is rather thrombogenic, hence there is a need to ensure adequate anticoagulation prior to doing so.

Heparin is administered, usually at 300 - 400 units/kg to obtain an activated clotting time of at least 480 seconds.

We've written a post on off-pump bypass surgery here if you're interested