Anesthesiology
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Tissue damage may produce hyperalgesia, allodynia, and persistent pain. The authors recently reported that fentanyl elicits analgesia but also activates N-methyl-D-aspartate-dependent pain facilitatory processes opposing analgesia. In nonsuffering rats, this leads to a long-lasting enhancement in pain sensitivity. The current study assessed whether fentanyl could amplify carrageenan-induced hyperalgesia. ⋯ Central sensitization in inflammatory pain states is reinforced by an opiate treatment, which could be prevented by N-methyl-D-aspartate receptors blockade.
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Randomized Controlled Trial Multicenter Study Comparative Study Clinical Trial
A multicenter study comparing the ProSeal and Classic laryngeal mask airway in anesthetized, nonparalyzed patients.
The laryngeal mask airway ProSeal (PLMA), a new laryngeal mask device, was compared with the laryngeal mask airway Classic (LMA) with respect to: (1) insertion success rates and times; (2) efficacy of seal; (3) fiberoptically determined anatomic position; (4) orogastric tube insertion success rates and times; (5) total intraoperative complications; and (6) postoperative sore throat in nonparalyzed adult patients undergoing general anesthesia, hypothesizing that these would be different. ⋯ In anesthetized, nonparalyzed patients, the LMA is easier and quicker to insert, but the PLMA forms a better seal and facilitates easier and quicker orogastric tube placement. The incidence of total intraoperative complications and postoperative sore throat are similar.
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Randomized Controlled Trial Clinical Trial
Effects of the selective H1 and H2 histamine receptor antagonists loratadine and ranitidine on autonomic control of the heart.
H1 and H2 histamine receptor subtypes are present throughout the heart and may be involved in disturbances of cardiac rhythm that occur during anaphylaxis. Although H1 and H2 receptor antagonists are used in the treatment of anaphylaxis, there have been reports implicating these drugs in the genesis of dysrhythmias. This study was designed to investigate the effects of the selective H1 and H2 receptor antagonists loratadine and ranitidine on physiologic autonomic control of the healthy cardiovascular system. ⋯ H1 receptor antagonism with loratadine does not influence physiologic cardiovascular control in young healthy subjects. However, the altered cardiac sympathovagal balance after oral administration of the H2 receptor antagonist ranitidine indicates a shift toward sympathetic predominance in heart rate control. The authors postulate that this could have implications regarding susceptibility to arrhythmias in conditions of heightened sympathetic stimulation.
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Perioperative myocardial ischemia is conventionally monitored using five electrocardiographic leads, with only one precordial lead placed at V5. This is based on studies from more than a decade ago. The authors reassessed this convention by analyzing data obtained from continuous on-line 12-lead electrocardiographic monitoring. ⋯ As a single lead, V4 is more sensitive and appropriate than V5 for detecting prolonged postoperative ischemia and infarction. Two precordial leads or more are necessary so as to approach a sensitivity of greater than 95% for detection of perioperative ischemia and infarction.
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Clinical Trial
Use of dynamic negative airway pressure (DNAP) to assess sedative-induced upper airway obstruction.
Traditional methods of assessing ventilatory effects of sedative agents do not measure their propensity to cause upper airway obstruction (UAO). The primary objective of this study was to develop a method, using dynamic negative airway pressure (DNAP), for replicating UAO during deep sedation. ⋯ Dynamic Negative Airway Pressure is a useful method for provoking midazolam-induced UAO, and may potentially be used to compare the potential for different sedatives and patient factors to cause UAO. Flumazenil was completely effective in reversing the potential for midazolam to cause UAO.