text: what type of general anesthesia was used in 1958?   as the first author mentioned, halothane was the potent inhalational anesthetic that people probably used in 1958.  it came out in 1956.  you received this gas through the circle system ventilator which was already in use at that time.  in addition there was muscle relaxant used (most likely curare at that time) and a narcotic (most likely morphine at that time.)