Morue HI, et al. - Researchers assessed whether the addition of a continuous intravenous infusion of ketamine could reduce episodes of respiratory depression that are frequently observed in association with a target-controlled infusion (TCI) of remifentanil. They randomized women undergoing oocyte retrieval to receive either a ketamine infusion (40 μg kg^-1 min^-1 over 5 min followed by 2.5 μg kg^-1 min^-1) or a 0.9% saline infusion in addition to the variable remifentanil TCI. They found that neither the incidence nor the severity of respiratory depression was decreased by the addition of low plasma levels of ketamine to a TCI remifentanil conscious sedation technique. Continuous monitoring of capnography and oxygen saturation was always required.