[The so-called venous air embolism: historical aspects and current diagnosis, prophylaxis and therapy]

The so-called venous air embolism is known as a complication not only of surgical operations but also of other procedures. Two conditions must be fulfilled: a lesion of a non collapsible vein; and a pressure gradient from outside to inside the vein, as occurs for instance during puncture of a large vein in a hypovolemic patient. Air entry into veins is a frequent occurrence during neurosurgery in sitting patients, and thus most diagnostic, prophylactic, and therapeutic innovations were proposed by neuroanesthetists. Due to advances in technique, truly dangerous cases of so-called venous air embolism during neurosurgery in patients in the sitting position are very rare.