title: Variables not parameters.
authors.affiliation: Retired anaesthetist, Bristol, UK. nevwgoodman@mac.com.
authors.forename: N W
authors.initials: NW
authors.lastname: Goodman
mesh_terms: D000758:Anesthesia / Q000009:adverse effects*; D006801:Humans; D019990:Perioperative Care; D012308:Risk Management