Anesthesiology
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Based primarily on results obtained during exercise treadmill testing, electrocardiographic (ECG) leads II and V5 are the suggested optimal leads for detecting intraoperative myocardial ischemia. However, these recommendations have not been validated in this setting using all 12 ECG leads. Accordingly, the authors studied 105 patients with known or suspected coronary artery disease (CAD) undergoing noncardiac surgery with general anesthesia by continuously recording the 12-lead ECG intraoperatively in all patients. ⋯ V4 is more sensitive than lead II, and should be considered as a second choice. However, lead II, superior for detection of atrial dysrhythmias, is more easily obtained with conventional monitors. The use of all three would appear to be the optimal arrangement for most clinical needs, and is recommended if the clinician has the capability.
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Comparative Study
Acute cerebral effects of isotonic crystalloid and colloid solutions following cryogenic brain injury in the rabbit.
Despite the numerous studies examining the relative merits of crystalloids versus colloids for expansion of intravascular volume, little attention has been directed to the cerebral effects of these solutions. In particular, the effect of changes in plasma oncotic pressure on brain water content are poorly understood. The authors recently examined the acute effects of changes in plasma osmolality and colloid oncotic pressure in normal animals, and found that a 65% reduction in oncotic pressure had no detectable effect on brain water content or intracranial pressure. ⋯ The saline group required approximately twice as much fluid (207 +/- 17 ml) to maintain a stable mean arterial pressure and central venous pressure as did the hetastarch (105 +/- 14 ml) or albumin (103 +/- 29 ml) groups. As intended, the oncotic pressure decreased by a mean of 9.6 +/- 2.4 mmHg in the saline group, while remaining stable in the hetastarch and albumin groups. There were no significant changes in osmolality in any group during the hemodilution period.(ABSTRACT TRUNCATED AT 250 WORDS)