Pleural fluid CRP, LDH, and pH as predictors of successful pleurodesis in malignant pleural effusions

BackgroundPleurodesis fails in 10–40% of patients with recurrent malignant pleural effusions (MPEs) and dyspnea. An accurate definition of the different characteristics of the patient would help to identify more precisely the population mostly benefiting from pleurodesis.AimWe aimed to assess the values of the initial pleural fluid LDH, CRP and pH characteristics on pleurodesis outcome for MPEs.MethodsBetween April 2013 and December 2014, 40 patients with MPE were subjected to pleurodesis with doxycycline and were divided into two groups, successful pleurodesis (group I) and failed pleurodesis (group II) according to their radiographic response at the end of the 4 weeks follow-up period. Before pleurodesis, pleural tapping and the initial pleural fluid biochemical parameters (Total protein, glucose, PH, LDH and CRP levels) were measured.ResultsAfter 4 weeks follow up, the success rate of pleurodesis was 62.5%. In successful pleurodesis, the initial total pleural fluid proteins, pleural fluid LDH and pleural fluid CRP were significantly lower than unsuccessful pleurodesis, with P-values <0.05, <0.001, <0.05 respectively while, pleural fluid glucose was statistically very highly significantly lower at the unsuccessful pleurodesis group (P < 0.001). Both groups together revealed positive correlation between pleural fluid LDH at one side and (pleural fluid CRP and proteins) at the other side (P-value < 0.01 and <0.05) respectively, while, there was a negative correlation between pleural fluid LDH and pleural fluid glucose (P-value < 0.01). The complications of tube thoracotomy and pleurodesis in both successful and failed pleurodesis were higher in unsuccessful pleurodesis than in successful pleurodesis.ConclusionHigh CRP, high LDH and low PH in MPEs have a poorer outcome of pleurodesis. So, it may be advantageous when selecting patients for pleurodesis to include in their routine tests, the initial pleural fluid CRP, LDH and PH levels.