This document provides instructions for removing air or fluid from the pleural cavity via a procedure called a thoracentesis. It lists common reasons for needing the procedure such as pneumothorax, empyema, or malignant pleural effusion. It then outlines the necessary steps including getting imaging, administering local anesthetic, inserting a chest tube between the ribs, attaching it to suction, and monitoring for complications. The goal is to fully re-expand the lung and ensure no further air leaks or bleeding once drainage has ceased.