The objective of this study was to determine the safety and value of t
horacentesis in an ICU, Thoracentesis is a safe procedure for critical
ly ill patients, even those on mechanical ventilators, and usually con
firms the suspected diagnosis. However, thoracentesis revealed an unex
pected diagnosis that changed management in 12% of patients. Repeat or
contralateral thoracentesis is indicated when either the clinical cou
rse is inconsistent or map represent a complication of the original di
agnosis.