The best protocol of perioperative beta-blockers remains uncertain.Previous studies have demonstrated that tight heart rate control by beta-blockers reduced perioperative myocardial ischemia and improved clinical outc...The best protocol of perioperative beta-blockers remains uncertain.Previous studies have demonstrated that tight heart rate control by beta-blockers reduced perioperative myocardial ischemia and improved clinical outcomes.However,the recent studies have failed to provide evidence to support perioperative beta blockers,with potential increased mortality as showed in the POISE trial.In this paper,perioperative use of beta-blockers will be discussed,especially about the evolution of their perioperative therapeutic application and current status.展开更多
Background As a new electroencephalogram （EEG） signal processing technique for monitoring the depth of anesthesia, entropy consists of two indices： reaction entropy （RE） and state entropy （SE）. Our study compar...Background As a new electroencephalogram （EEG） signal processing technique for monitoring the depth of anesthesia, entropy consists of two indices： reaction entropy （RE） and state entropy （SE）. Our study compared entropy with classical bispectral index （BIS） in reduction of myoelectrical interference and noxious stimuli with EEG signals. Methods Two hundred and eighty patients （ASA I-II, 18-60 years old） undergoing scheduled surgeries from seven medical centers were enrolled. Anesthesia induction was managed with propofol via the target-controlled infusion （TCI） system. The results of BIS, RE, SE, mean arterial pressure （MAP） and heart rate （HR） were recorded before anesthesia induction, at the moment of unconsciousness, before and 2 minutes after administration of muscle relaxant, and before and one and three minutes after the tracheal intubation. Results The values of half maximum effective concentrations （EC50）, 5% effective concentrations （EC05） and 95% effective concentrations （EC95） of propofol effect-site concentration at the onset of unconsciousness were 1.2 （1.1-1.3 μg/ml）, 2.5 （2.4-2.5 μg/ml） and 3.7 （3.7-3.8 μg/ml）, while those of the predicted plasma propofol concentration were 2.8 （2.7-2.9 μg/ml）, 3.9 （3.8-3.9 μg/ml） and 4.9 （4.8-5.0μg/ml）, respectively. The values of BIS, SE and RE were 62, 59 and 63 when 50% of patients lost consciousness, and 79, 80, 85 and 42, 37, 44, respectively, when 5% and 95% of patients were unconscious. The values of BIS, RE and SE dropped two minutes after the injection of muscle relaxant, but there were no significant differences between RE and SE. MAP and HR increased visibly, which indicated a reaction to tracheal intubation; the values of BIS, RE and SE, however, did not display any significant changes. Conclusions This large-sample multicentric study confirmed the values of RE and SE as approximating BIS value, at the onset of unconsciousness during propofol TCI anesthesia. After elimination of myoelectrical activation, all values of RE, SE and BIS decreased significantly and the three indices were less sensitive to noxious stimuli than cardiovascular responses.展开更多
文摘The best protocol of perioperative beta-blockers remains uncertain.Previous studies have demonstrated that tight heart rate control by beta-blockers reduced perioperative myocardial ischemia and improved clinical outcomes.However,the recent studies have failed to provide evidence to support perioperative beta blockers,with potential increased mortality as showed in the POISE trial.In this paper,perioperative use of beta-blockers will be discussed,especially about the evolution of their perioperative therapeutic application and current status.
文摘Background As a new electroencephalogram （EEG） signal processing technique for monitoring the depth of anesthesia, entropy consists of two indices： reaction entropy （RE） and state entropy （SE）. Our study compared entropy with classical bispectral index （BIS） in reduction of myoelectrical interference and noxious stimuli with EEG signals. Methods Two hundred and eighty patients （ASA I-II, 18-60 years old） undergoing scheduled surgeries from seven medical centers were enrolled. Anesthesia induction was managed with propofol via the target-controlled infusion （TCI） system. The results of BIS, RE, SE, mean arterial pressure （MAP） and heart rate （HR） were recorded before anesthesia induction, at the moment of unconsciousness, before and 2 minutes after administration of muscle relaxant, and before and one and three minutes after the tracheal intubation. Results The values of half maximum effective concentrations （EC50）, 5% effective concentrations （EC05） and 95% effective concentrations （EC95） of propofol effect-site concentration at the onset of unconsciousness were 1.2 （1.1-1.3 μg/ml）, 2.5 （2.4-2.5 μg/ml） and 3.7 （3.7-3.8 μg/ml）, while those of the predicted plasma propofol concentration were 2.8 （2.7-2.9 μg/ml）, 3.9 （3.8-3.9 μg/ml） and 4.9 （4.8-5.0μg/ml）, respectively. The values of BIS, SE and RE were 62, 59 and 63 when 50% of patients lost consciousness, and 79, 80, 85 and 42, 37, 44, respectively, when 5% and 95% of patients were unconscious. The values of BIS, RE and SE dropped two minutes after the injection of muscle relaxant, but there were no significant differences between RE and SE. MAP and HR increased visibly, which indicated a reaction to tracheal intubation; the values of BIS, RE and SE, however, did not display any significant changes. Conclusions This large-sample multicentric study confirmed the values of RE and SE as approximating BIS value, at the onset of unconsciousness during propofol TCI anesthesia. After elimination of myoelectrical activation, all values of RE, SE and BIS decreased significantly and the three indices were less sensitive to noxious stimuli than cardiovascular responses.
