Bilateral tension pneumothorax due to a defective anesthesia breathing circuit filter

A 25-year-old healthy patient developed bilateral tension pneumothorax during general endotracheal anesthesia due to a defective anesthesia breathing circuit filter. Prompt diagnosis and treatment of the pneumothorax was facilitated by the use of capnography and pulse oximetry. The manufacturing process of the breathing circuit and filter that made this accident possible has since been corrected by the manufacturer. Anesthesiologists must be alert to the possibility of such accidents with any breathing system using bacterial filters.