Complications include Pneumothorax (increased risk because apical pleura [especially on left side] is close to needle insertion path) Arterial puncture Hematoma (increased risk because clavicle impedes application of external pressure to stop subclavian arterial or venous bleeding) Damage to the vein Hemothorax Air embolism Catheter misplacement * (eg, internal jugular vein, thoracic duct) Arrhythmias or atrial perforation, typically caused by guidewire or catheter Nerve damage Infection Thrombosis (due to the catheter itself) * Rare complications due to catheter misplacement include arterial catheterization, hydrothorax, hydromediastinum, and damage to the tricuspid valve.