1) Temperature – A cold flap indicates poor blood supply, it should be warm
2) Capillary refill – Normal capillary refill is approximately 3 seconds. Deviations from this figure could indicate vascular compromise.
3) Texture – If the flap is swollen (turgid) and firm it may represent a congested flap resulting from poor venous supply. A "spongy" flap could be an indicator of poor arterial supply
4) Colour – A change in colour is usually one of the first signs to indicate there is an issue with the flap. The flap should be the same colour as the original tissue surrounding the donor site. A pale or blue flap is particularly concerning.
5) Doppler signal - The probe is placed near the site of anastomosis and an audible signal indicating blood flow should be observed (‘whooshing’ sound). This type of test will be done by your registrar/consultant. (Try to ensure you have a working Doppler for the ward round)
6) Pin-prick testing - The flap is scratched with a blue needle anf if bleeding is observed from this site it indicates a healthy flap. IMPORTANT: this test is only to be done by a consultant!
If you have any concerns about the flap, always escalate to your seniors. Flap failure is a major surgical complication and necessitates a return to theatre.
If you are on-call late or overnight, try to see the flap when the operation ends or in recovery. The flap should also be observed throughout the day. Ensure you note the colour of the flap as there are many occasions when others may call you to say that flap has become pale when in fact, the skin paddle was pale in the first place . Regardless, if a colleague asks you to examine a free flap, notify your registrar.