Anesthesiology. 119(1):61-70, July 2013.
The choice of potent volatile anesthetic may prolong hospitalization, increasing the cost of patient care. The hypothesis that duration of hospitalization is longer in patients anesthetized with isoflurane than in patients anesthetized with sevoflurane was tested first in a propensity-matched retrospective analysis and subsequently in a prospective alternatingintervention trial. The retrospective study, which included 2,898 triplets matched on anesthetic used, found the duration of hospitalization was shorter in patients anesthetized with sevoflurane or desflurane than in those anesthetized with isoflurane. However, the prospective trial, which included 1,584 operations, found no difference in length-of-stay between patients anesthetized with isoflurane and those anesthetized with sevoflurane. This illustrates the importance of testing the results of even a very robust retrospective analysis with an appropriately designed prospective study.