PLEURAL EFFUSION A sample of fluid from the pleural space by thoracentesis (胸腔穿刺)is the key to determining the etiology of a pleural effusion.The tests needed to make a diagnosis require a relatively small amount of fluid (30 to 50 mL). Larger volumes of fluid can be removed (1 to 1.5 L)in an attempt to alleviate symptoms(缓解症状).Removing volumes greater than 1.5 L may result in re-expansion pulmonary edema(复张性肺水肿)Most thoracenteses can be performed at the bedside,using ultrasound guidance (超声引导)to enhance the procedure's safety.第 一 部 分 A sample of fluid from the pleural space by thoracentesis （胸腔穿刺） is the key to determining the etiology of a pleural effusion. The tests needed to make a diagnosis require a relatively small amount of fluid (30 to 50 mL). Larger volumes of fluid can be removed (1 to 1.5 L) in an attempt to alleviate symptoms（缓解症状）. Removing volumes greater than 1.5 L may result in re-expansion pulmonary edema（复张性肺水肿） Most thoracenteses can be performed at the bedside, using ultrasound guidance （超声引导） to enhance the procedure’s safety. PLEURAL EFFUSION