Recent investigations indicate a site of cardiac representation within the left insular cortex of the rat. Moreover, the results of lesion studies suggest left-sided insular dominance for sympathetic cardiovascular effects. It is unclear whether similar representation exists within the human insular cortex. Five epileptic patients underwent intraoperative insular stimulation prior to temporal lobectomy for seizure control. On stimulation of the left insular cortex, bradycardia and depressor responses were more frequently produced than tachycardia and pressor effects (p less than 0.005). The converse applied for the right insular cortex. We believe this to be the first demonstration of cardiovascular changes elicitable during insular stimulation in humans, and of lateralization of such responses for a cortical site. In humans, unlike the rat, there appears to be right-sided dominance for sympathetic effects. These findings may be of relevance in predicting the autonomic effects of stroke in humans and in the explanation of sudden unexpected epileptic death.

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Accurate situation awareness (SA) of medical staff is integral for providing optimal performance during the treatment of patients. An understanding of SA and how it affects treatment of patients is therefore crucial for patient safety and an essential element for research on human factors in anesthesia. This review describes the concept of SA in the anesthesia environment, including the interaction with associated medical teams. Different approaches for its assessment in the work environment of anesthesia are provided. Factors contributing to expertise in SA are described and approaches for the training of SA in anesthesia are discussed, as are types of errors that occur during the development of SA. Finally, the authors briefly present strategies to improve SA during daily anesthesia practice through altered designs of monitor displays.

Perioperative stroke after noncardiac, nonneurosurgical procedures is more common than generally acknowledged. It is reported to have an incidence of 0.05-7% of patients. Most are thrombotic in origin and are noted after discharge from the postanesthetic care unit. Common predisposing factors include age, a previous stroke, atrial fibrillation, and vascular and metabolic diseases. The mortality is more than two times greater than in strokes occurring outside the hospital. Delayed diagnosis and a synergistic interaction between the inflammatory changes normally associated with stroke, and those normally occurring after surgery, may explain this increase.Intraoperative hypotension is an infrequent direct cause of stroke. Hypotension will augment the injury produced by embolism or other causes, and this may be especially important in the postoperative period, during which monitoring is not nearly as attentive as in the operating room. Increased awareness and management of predisposing risk factors with early detection should result in improved outcomes. STROKE is an important cause of morbidity and mortality, particularly in patients more than 65 yr old. In cardiac, neurologic, and carotid surgery, the incidence is known to be high (2.2-5.2%).1 However, little is known regarding perioperative stroke following other types of surgery including general, urologic, orthopedic, thoracic, and gynecologic procedures. The aims of this article are to review the incidence, pathophysiology, risk factors, and outcomes associated with perioperative stroke following noncardiac, nonneurologic, and vascular surgery. Suggestions regarding the timing of elective surgery after stroke and ways in which one can reduce the incidence and improve outcomes are also outlined. DefinitionThe World Health Organization definition of stroke is a "focal or global neurologic deficit of cerebrovascular cause that persists beyond 24 h or is interrupted by death within 24 h." Transient ischemic attack is acute loss of focal cerebral or ocular function with symptoms lasting less than 24 h and is usually presumed to be embolic or thrombotic in origin. In addition, a third type of cerebrovascular event has recently attracted much attention in the nonsurgical setting. Covert stroke is an asymptomatic ischemic event usually only detected by advanced neuroimaging techniques, such as diffusion-weighted magnetic resonance imaging sequences.2 Although the diagnosis is often missed at the time of the event, covert stroke has been associated with an adverse effect on cognitive function and quality of life. Currently other than in cardiac and carotid artery surgery, there is no study evaluating the incidence, impact, and risk factors of covert stroke in the general surgical population.

The question of which is the optimum technique to intubate the trachea in a patient who may have a cervical(C)-spine injury remains unresolved. We compared, using fluoroscopic video, C-spine motion during intubation for Macintosh 3 blade, GlideScope, and Intubating Lighted Stylet, popularly known as the Lightwand or Trachlight. Thirty-six healthy patients were randomized to participate in a crossover trial of either Lightwand or GlideScope to Macintosh laryngoscopy, with in-line stabilization. C-spine motion was examined at the Occiput-C1 junction, C1-2 junction, C2-5 motion segment, and C5-thoracic motion segment during manual ventilation via bag-mask, laryngoscopy, and intubation. Time to intubate was also measured. C-spine motion during bag-mask ventilation was 82% less at the four motion segments studied than during Macintosh laryngoscopy (P < 0.001). C-spine motion using the Lightwand was less than during Macintosh laryngoscopy, averaging 57% less at the four motion segments studied (P < 0.03). There was no significant difference in time to intubate between the Lightwand and the Macintosh blade. C-spine motion was reduced 50% at the C2-5 segment using the GlideScope (P < 0.04) but unchanged at the other segments. Laryngoscopy with GlideScope took 62% longer than with the Macintosh blade (P < 0.01). Thus, the Lightwand (Intubating Lighted Stylet) is associated with reduced C-spine movement during endotracheal intubation compared with the Macintosh laryngoscope.

Dynamic single-section CT scanning to measure CBV and CBF on the basis of a noncarotid input is a highly accessible and cost-effective blood flow measurement technique.

Cerebral autoregulation describes a mechanism that maintains cerebral blood flow stable despite fluctuating perfusion pressure. Multiple nonperfusion pressure processes also regulate cerebral perfusion. These mechanisms are integrated. The effect of the interplay between carbon dioxide and perfusion pressure on cerebral circulation has not been specifically reviewed. On the basis of the published data and speculation on the aspects that are without supportive data, the authors offer a conceptualization delineating the regulation of cerebral autoregulation by carbon dioxide. The authors conclude that hypercapnia causes the plateau to progressively ascend, a rightward shift of the lower limit, and a leftward shift of the upper limit. Conversely, hypocapnia results in the plateau shifting to lower cerebral blood flows, unremarkable change of the lower limit, and unclear change of the upper limit. It is emphasized that a sound understanding of both the limitations and the dynamic and integrated nature of cerebral autoregulation fosters a safer clinical practice.

The International Standards for a Safe Practice of Anesthesia were developed on behalf of the World Federation of Societies of Anaesthesiologists (WFSA), a nonprofit organization representing anesthesiologists in 150 countries, and the World Health Organization (WHO). The recommendations have been approved by WHO and the membership of WFSA. These Standards are applicable to all anesthesia providers throughout the world. They are intended to provide guidance and assistance to anesthesia providers, their professional organizations, hospital and facility administrators, and governments for maintaining and improving the quality and safety of anesthesia care. The Standards cover professional aspects; facilities and equipment; medications and intravenous fluids; monitoring; and the conduct of anesthesia. HIGHLY RECOMMENDED standards, the functional equivalent of mandatory standards, include (amongst other things): the continuous presence of a trained and vigilant anesthesia provider; continuous monitoring of tissue oxygenation and perfusion by clinical observation and a pulse oximeter; intermittent monitoring of blood pressure; confirmation of correct placement of an endotracheal tube (if used) by auscultation and carbon dioxide detection; the use of the WHO Safe Surgery Checklist; and a system for transfer of care at the end of an anesthetic. The International Standards represent minimum standards and the goal should always be to practice to the highest possible standards, preferably exceeding the standards outlined in this document.