Contraindications to Thoracentesis Absolute contraindications None Relative contraindications Bleeding disorder or anticoagulation Altered chest wall anatomy Cellulitis or herpes zoster at the site of thoracentesis puncture Pulmonary disease severe enough to make complications life threatening Uncontrolled coughing or an uncooperative patient Complications of Thoracentesis Major complications include Pneumothorax Bleeding (hemoptysis due to lung puncture) Re-expansion pulmonary edema and / or hypotension (1) Hemothorax due to damage to intercostal vessels Puncture of the spleen or liver Vasovagal syncope Bloody fluid that does not clot in a collecting tube indicates that blood in the pleural space was not iatrogenic, because free blood in the pleural space rapidly defibrinates.