True about lights criteria are all except
Ratio of pleural fluid protein to serum protein if greater than 0.5 - then it is exudative pleural effusion. Ratio of pleural fluid LDH and serum LDH if greater that 0.5 - then its exudative pleural effusion. Plueral fluid LDH 2 to 3 times the upper limit of serum LDH is diagnostic of exudative pleural effusion. At least one of the 3 criteria is sufficient to diagnose exudative pleural effusion.