[Extra-arachnoid subdural injection, an accident of peridural anesthesia].

Two cases are presented, with accidents of peridural anesthesia, Anesthesia of the entire brain stem, paralysis of the intercostal muscles, and of the upper limbs, apnoea and miosis that developed later indicate an extension of the anesthetic effects far higher that it could have been expected considering the technical details of the procedure. On the other hand the absence of any durable coma, of extreme mydriasis, and of severe arterial hypotension, as well as the relatively rapid retrocession of the additional effects of the administration of an anesthetic exclude the possibility of total rachianesthesia, and it can be concluded that there was an accidental injection of anesthetic in the extra-arachnoid subdural space.