Interpreting effusion samples can be confusing, so try to think of effusions as if you were collecting a blood sample.

Septic effusion
Septic effusion.

Many of the in-clinic diagnostic tests that apply to blood samples also apply to effusions, such as:

  • PCV/total protein
  • smears
  • glucose
  • lactate
  • potassium
  • creatinine
  • bilirubin

It’s not enough to only check the protein concentration of the effusion then classify it as either a transudate, modified transudate or exudate and leave it at that – there is more information left to extract from that sample.

Challenging diagnosis

Determining if an effusion is septic can be a challenge. Here are the steps I take.

analysis
Abdominal and peripheral blood gas analysis.
  1. Perform a cytological examination of your effusion in the smear and look for inflammatory cells and the presence of bacteria. Look inside the cells as well as outside. If you don’t see bacteria it does not mean it isn’t a septic effusion, and only a couple bacteria are needed for me to call it septic.
  2. Glucose and lactate: You need to compare the glucose levels in the effusion with blood glucose levels. If the effusion glucose level is less than serum glucose, it is more likely you have a septic exudate. This makes sense in that bacteria would metabolise glucose in the effusion, leading to lower glucose levels. A by-product of metabolism is, of course, lactate. Therefore, you next need to check the lactate levels in the effusion and compare it to the serum lactate level. If lactate level in the effusion is more than the serum lactate level, then again you have more evidence you are dealing with a septic exudate.

Try to measure glucose and lactate from both blood and effusion samples at the same time on the same machine. Keep in mind glucose and lactate values are less accurate for monitoring for the presence of bacteria in post-surgical patients.

View your activity >

Leave a Reply

Be the First to Comment!

Notify of
avatar

wpDiscuz

related content

Zoetis' Trocoxil chewable tablets are back in stock following a "supply shortage", says the company.

2 mins

Rory O’Connor offers practical advice for VNs to prevent mental health issues occurring – and to ensure you don’t suffer in silence.

19 mins

Six veterinary research projects aimed at improving areas of livestock and equine welfare have gained funding from the Animal Welfare Foundation.

4 mins

Having previously discussed the components of a fluid therapy plan, Gerardo Poli looks at maintenance rates and crystalloid use.

3 mins

Lotfi El Bahri discusses how this low-cost medication can be dangerous for small animals and how to spot signs of intoxication.

13 mins

Elisabetta Mancinelli takes a closer look at this condition and how it can be diagnosed, as well as suggesting various treatments.

14 mins