Anesthesiology
-
Randomized Controlled Trial Clinical Trial
Intravenous remifentanil: placental transfer, maternal and neonatal effects.
Remifentanil has not been studied in obstetric patients. This study evaluates the placental transfer of remifentanil and the neonatal effects when administered as an intravenous infusion. ⋯ Remifentanil crosses the placenta but appears to be rapidly metabolized, redistributed, or both. Maternal sedation and respiratory changes occur, but without adverse neonatal or maternal effects.
-
Randomized Controlled Trial Clinical Trial
Causes and prediction of maldistribution during continuous spinal anesthesia with isobaric or hyperbaric bupivacaine.
Many cases of cauda equina syndrome after maldistribution of local anesthetics during continuous spinal anesthesia have been reported. In experiments, a caudad route of catheter travel and the use of hyperbaric agents have been shown to induce these limited blocks. The aim of this clinical study was to verify this hypothesis and seek a predictive factor for the maldistribution of bupivacaine. ⋯ Hyperbaric solutions do not appear to be a clinical factor in the development of limited block. The principle factor causing the maldistribution of bupivacaine is the caudal orientation of the tip of the end-hole catheter rather than its level or the route of catheter travel.
-
This study prospectively evaluated the ability of aspiration to detect intravascular placement of multiple-orifice epidural catheters. ⋯ Under the conditions of this study, which include using multiple-orifice catheters and dilute solutions of local anesthetic and opioid, aspiration and incremental drug injection alone safeguard against the risks of intravenously positioned local anesthetics. These results should not be extrapolated to other clinical settings without further study.
-
Randomized Controlled Trial Clinical Trial
Upper airway reflexes during a combination of propofol and fentanyl anesthesia.
The effects of intravenous anesthetics on airway protective reflexes have not been fully explored. The purpose of the present study was to characterize respiratory and laryngeal responses to laryngeal irritation during increasing doses of fentanyl under propofol anesthesia. ⋯ Incremental doses of fentanyl depress airway reflex responses in a dose-related manner, except for apnea with laryngospasm.