Introduction: Patients with malignant pleural effusions (MPE) have a poor life expectancy and a high symptom burden. Definitive management strategies include chest drain and pleurodesis or placement of an indwelling pleural catheter. A meta analysis showed that 76% - 82% of patients had a successful pleurodesis with sterile talc. It has been postulated that patients who experience a greater inflammatory response or experience more pain are more likely to have a successful pleurodesis. Trapped lung is associated with a lower rate of pleurodesis success and it is thought that the number of previous interventions may be related to the development of trapped lung. Methods: A post hoc analysis from the TIME 1 trial was undertaken to establish the accuracy of these hypotheses. 320 patients were included who had a diagnosis of MPE. Results: There was a correlation between the number of previous ipsilateral aspirations and the incidence of trapped lung (p=0.015). Conclusion: Inflammation may play a factor in pleurodesis success as patients with a greater rise in CRP were more likely to have a successful pleurodesis. There is no evidence to support the hypothesis that patients who have more pain are more likely to have a successful pleurodesis. The correlation between the incidence of trapped lung and previous pleural interventions needs further study into whether or not there is a causal relationship.