Pleural Fluid (Lights Criteria) Flashcards
What is the significance of a pleural fluid haematocrit level less than 1%?
Non-significant
Indicates that there is no significant bleeding into the pleural space.
What conditions are indicated by a pleural fluid haematocrit level between 1-20%?
Cancer, PE, trauma, pneumonia
.
What does a pleural fluid haematocrit level greater than 50% indicate?
Haemothorax
This suggests significant bleeding into the pleural space.
What does cloudy or turbid pleural fluid suggest?
Possible infection
Cloudiness can indicate the presence of infection or other pathological processes.
What triglyceride level in pleural fluid is indicative of chylothorax?
> 110mg/dL
Chylothorax is the accumulation of lymphatic fluid “chye” in the pleural space.
What does a putrid odour in pleural fluid suggest?
Possible anaerobic infection
This can indicate the presence of certain types of bacteria that thrive in low-oxygen environments.
What is the purpose of Light’s criteria?
Determines presence of exudate
It assesses pleural fluid characteristics to differentiate between exudative and transudative pleural effusions.
What pleural fluid protein to serum protein ratio indicates exudate according to Light’s criteria?
> 0.5
A higher ratio suggests that the fluid is exudative.
What pleural fluid LDH to serum LDH ratio indicates exudate according to Light’s criteria?
> 0.6
This ratio helps to identify exudative pleural effusions.
What pleural fluid LDH level indicates exudate when compared to serum LDH?
> 2/3 of upper value for serum LDH
This criterion is used alongside others to confirm exudative nature.
What pleural fluid albumin level compared to serum albumin confirms exudate if results are equivocal?
<1.2g/dL
This helps clarify the nature of the pleural effusion when other tests are inconclusive.
