Anesthesiology
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Randomized Controlled Trial Clinical Trial
Transcutaneous electrical stimulation of an auricular acupuncture point decreases anesthetic requirement.
German anesthesiologists have long used transcutaneous electrical stimulation of an acupuncture point near the tragus to reduce anesthetic requirement in unblinded and uncontrolled trials. This is known as auricular electrically stimulated analgesia. The authors therefore tested the hypothesis that auricular electrically stimulated analgesia reduces anesthetic requirement. ⋯ This double-blinded trial with an objective outcome demonstrates that electrical stimulation of the lateralization control point significantly reduces anesthetic requirement.
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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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Randomized Controlled Trial Clinical Trial
Electroacupuncture prophylaxis of postoperative nausea and vomiting following pediatric tonsillectomy with or without adenoidectomy.
Electrical stimulation of acupuncture point P6 reduces the incidence of postoperative nausea or vomiting (PONV) in adult patients. However, acupressure, laser stimulation of P6, and acupuncture during anesthesia have not been effective for reducing PONV in the pediatric population. The authors studied the effect of electrical P6 acupuncture in awake pediatric patients who had undergone surgery associated with a high incidence of PONV. ⋯ Perioperative P6 electroacupuncture in awake patients significantly reduced the occurrence of nausea compared with the sham and control groups, but it did not significantly reduce the incidence or number of episodes of emesis or the use of rescue antiemetics. Sham acupuncture may exacerbate the severity but not the incidence of emesis. The efficacy of P6 acupuncture for PONV prevention is similar to commonly used pharmacotherapies. Its appropriate role in prevention and treatment of PONV requires further study.
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Clinical Trial Controlled Clinical Trial
Sympathetic neural activation evoked by mu-receptor blockade in patients addicted to opioids is abolished by intravenous clonidine.
Mu-opioid receptor blockade by naloxone administered for acute detoxification in patients addicted to opioids markedly increases catecholamine plasma concentrations, muscle sympathetic activity (MSA), and is associated with cardiovascular stimulation despite general anesthesia. The current authors tested the hypothesis that the alpha2-adrenoceptor agonist clonidine (1) attenuates increased MSA during mu-opioid receptor blockade for detoxification, and (2) prevents cardiovascular activation when given before detoxification. ⋯ Administration of the alpha2-adrenoceptor agonist clonidine decreases both increased MSA and catecholamine plasma concentrations observed after mu-opioid receptor blockade for detoxification. Furthermore, clonidine pretreatment prevents the increase in catecholamine plasma concentration that otherwise occurs during mu-opioid receptor blockade.
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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.