Anesthesiology
-
Randomized Controlled Trial Clinical Trial
Effect of infusion rate on thiopental dose-response relationships. Assessment of a pharmacokinetic-pharmacodynamic model.
The rate of administration of an intravenous anesthetic induction agent is an important variable determining the total dose required to reach a given endpoint, such as loss of consciousness (LOC). The influence of infusion rate on the dose-response relationship has not been described rigorously. In this study we characterized the effect of different thiopental infusion rates on the times and doses required to reach a clinical (induction) endpoint. ⋯ In this study we quantified the relationship between the rate of thiopental administration and the resultant cumulative thiopental dose necessary to produce LOC. This study validated a novel pharmacokinetic-pharmacodynamic model based on a four-compartment pharmacokinetic model and infusion quantal dose-response data. Finally, we demonstrated that thiopental dose-response relationships are dependent on drug administration rate, and found that the ability to predict this dependence accurately is influenced by the pharmacokinetics, pharmacodynamics, and median effect-site concentration used to simulate the dose-response relationships.
-
Randomized Controlled Trial Clinical Trial
The electroencephalogram does not predict depth of isoflurane anesthesia.
The power spectrum of the electroencephalogram (EEG) may be analyzed to provide quantitative measures of EEG activity (e.g., spectral edge, which defines the highest EEG frequency at which significant activity is found). The current study tested the hypothesis that spectral edge and similar measures distinguish different functional depths of anesthesia in humans. ⋯ We conclude that our EEG measures do not predict depth of anesthesia as defined by the response to surgical incision, the response to verbal command or the development of memory.
-
Randomized Controlled Trial Clinical Trial
Effect of flumazenil on recovery after midazolam and propofol sedation.
Flumazenil, a benzodiazepine antagonist, reverses midazolam-induced sedation and amnesia. We designed a double-blind study to evaluate the effects of flumazenil on patient outcome when flumazenil was used to reverse large or small doses of midazolam as part of standardized monitored anesthesia care. ⋯ Early recovery after breast biopsy procedures with midazolam sedation and flumazenil reversal is similar to recovery after propofol sedation. However, the beneficial effects of flumazenil were apparent only during the first 60 min after the procedure and resedation after discharge is an important consideration in the outpatient setting.
-
Postoperative epidural bupivacaine-morphine therapy. Experience with 4,227 surgical cancer patients.
We prospectively studied surgical cancer patients who received epidural bupivacaine-morphine to determine perioperative morphine use, side effects, and complications. ⋯ Continuous epidural analgesia with 0.05-0.1% bupivacaine and 0.01% morphine is an effective method of postoperative analgesia with a low incidence of side effects, that can be safely administered on the surgical wards with no special monitoring equipment.
-
Previous studies have noted a high incidence of adverse outcomes in the postanesthesia care unit (PACU), but few have examined associated factors and patient outcomes. To determine the frequency of acute, unanticipated respiratory problems and to examine the associated patient, surgical, and anesthetic factors, we prospectively collected preoperative, intraoperative, and postoperative data on 24,157 consecutive PACU patients who received a general anesthetic during a 33-month period. ⋯ A CRE is relatively rare. Multiple patient and surgical factors and specific aspects of anesthetic management are associated with the occurrence of a CRE in the PACU.