As-needed sedative and analges medications included in the study were chloral hydrate, lorazepam, midazolam, fentanyl, and morphine. Diphrnhydramine, when specifically administered for its sedative effects, was also include in the review; as-needed doses giver for indications of hypersensitivity, procedures, and insomnia were excluded from the study. As-needed medications were definitive
doses (and not associayed with range of dosages). All scheduled or pain /sedative medications given by continuous infusion were also excluded from the review In addition,2 subanalyses were performed to determine whether a change in administration disteibution was present: (1) as- needed doses administered during the 6 hours immediately after the operation were removed in I subanalysis and
(2) chloral hydrate doses ordered as a onetime. An unschrduled doses,and/or bedtime as needed for insomnia were removed in separate subanalysis.