Anesthesiology
-
Comparative Study Clinical Trial
Implicit memory for words played during isoflurane- or propofol-based anesthesia: the lexical decision task.
Unconscious processing of words during general anesthesia has been suggested after surgery with several tests of implicit memory. Patients can neither recall those words nor do they have explicit memories of other intraoperative events. It is unclear to what degree information is processed during general anesthesia and which tests are best suited to detect implicit memory. In the current study, a lexical decision paradigm not previously used to demonstrate implicit memory during anesthesia was used. ⋯ Balanced anesthesia techniques with isoflurane or propofol lead to only a minimal, statistically borderline implicit memory effect in the lexical decision paradigm.
-
Volatile anesthetics precondition against myocardial infarction, but it is unknown whether this beneficial action is threshold- or dose-dependent. The authors tested the hypothesis that isoflurane decreases myocardial infarct size in a dose-dependent fashion in vivo. ⋯ Concentrations of isoflurane as low as 0.25 MAC are sufficient to precondition myocardium against infarction. High concentrations of isoflurane may have greater efficacy to protect myocardium during conditions of low coronary collateral blood flow.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Impact of shorter-acting neuromuscular blocking agents on fast-track recovery of the cardiac surgical patient.
Residual paralysis associated with the use of long-acting muscle relaxants can delay recovery from anesthesia and surgery. The authors tested the hypothesis that use of shorter-acting neuromuscular blocking agents is associated with reductions in tracheal extubation times and intensive care unit (ICU) length of stay in patients undergoing cardiac surgery with cardiopulmonary bypass. ⋯ The use of shorter-acting neuromuscular blocking agents in patients undergoing cardiac surgery with cardiopulmonary bypass is associated with reductions in tracheal extubation times and symptoms of residual paresis.
-
Randomized Controlled Trial Clinical Trial
Lung function under high thoracic segmental epidural anesthesia with ropivacaine or bupivacaine in patients with severe obstructive pulmonary disease undergoing breast surgery.
Because general anesthesia with tracheal intubation can elicit life-threatening bronchospasm in patients with bronchial hyperreactivity, epidural anesthesia is often preferred. However, segmental high thoracic epidural anesthesia (sTEA) causes pulmonary sympathetic and respiratory motor blockade. Whether it can be safely used for chest wall surgery as a primary anesthetic technique in patients with chronic obstructive pulmonary disease or asthma is unclear. Furthermore, ropivacaine supposedly evokes less motor blockade than bupivacaine and might minimize side effects. To test the feasibility of the technique and the hypotheses that (1) sTEA with ropivacaine or bupivacaine does not change lung function and (2) there is no difference between sTEA with ropivacaine or bupivacaine, the authors studied 20 patients with severe chronic obstructive pulmonary disease (forced expiratory volume in 1 s [FEV1] = 52.1 +/- 17.3% of predicted [mean +/- SD]) or asthma who were undergoing breast surgery. ⋯ Despite sympathetic blockade, sTEA does not increase airway obstruction and evokes only a small decrease in FEV1 as a sign of mild respiratory motor blockade with no difference between ropivacaine and bupivacaine. Therefore, sTEA can be used in patients with severe chronic obstructive pulmonary disease and asthma undergoing chest wall surgery as an alternative technique to general anesthesia.