Effusion Analysis (Part 2)

Effusion Evaluation:

Last week we talked about how to determine if your effusion was septic. This week, let’s have a look into further evaluation of effusion samples.

If the effusion is haemorrhagic, here are some things to look out for.

Real or iatrogenic origin:

• Blood rapidly defibrinates in cavities so if it clots then it is iatrogenic
• If it swirls during collection it is more likely to be iatrogenic

Is it acute or chronic?

• Compare PCV/TP to peripheral, if sample PCV/TP = peripheral blood PCV/TP then a recent bleed is most likely the cause
• Always run a PCV/TP on haemorrhagic effusions don’t always assume it is from a large haemorrhage. Effusions with low PCVs e.g. 5 can look like frank blood!

  

• If sample PCV is low but TP is the same as peripheral blood then the bleed is likely chronic
• If erythrophagocytosis is present then it is chronic, look for macrophages, which contain dark brown to green pigments in your smear
• Also assess for the presence of clumped platelets, this can mean intravascular sampling or a very acute bleed

These tips should help with evaluating your effusion samples more effectively.