There is also established data on the use of outpatient tunnelled pleural catheters in malignant effusions. Besides providing effective drainage in cases with entrapped lungs, these catheters also result in spontaneous pleurodesis in 42 to 70% of cases. The attraction of the catheters is that it enables early discharge of patients who already have a terminal illness and an extremely poor prognosis (Prognosis is usually about 3-8 months depending on the primary) However, the pleural catheters do not allow biopsies to be taken from the pleura and the pleurodesis rate is both lower and slower than with talc poudrage.