Anesthesia and analgesia
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Anesthesia and analgesia · Aug 2004
Randomized Controlled Trial Comparative Study Clinical TrialDoes halothane really preserve cardiac baroreflex better than sevoflurane? A noninvasive study of spontaneous baroreflex in children anesthetized with sevoflurane versus halothane.
Heart rate profiles during the induction of anesthesia differ markedly between the administration of sevoflurane and halothane. Previous investigations have shown that halothane preserves cardiac parasympathetic activity more than sevoflurane. Because vagal drive to the sinus node is the main effector of arterial baroreflex control of heart rate, halothane may preserve cardiac baroreflex better than sevoflurane. ⋯ Similarly, the cross-spectral analysis between systolic blood pressure and RRI showed a decrease of the gain calculated in the low-frequency band, but the gain in the respiratory band was higher with halothane compared with sevoflurane. In children, the induction of anesthesia with halothane and sevoflurane is associated with a marked decrease of cardiac baroreflex activity. The persistence of respiratory RRI fluctuations under halothane might reflect reflex respiratory arrhythmia rather than efficient parasympathetic baroreflex activity.
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Anesthesia and analgesia · Aug 2004
ReviewEvidence-based management of critically ill patients: analysis and implementation.
A number of important clinical trials focusing on critically ill patients have been completed in the last few years. These trials have been among the first critical care clinical trials to demonstrate mortality reduction in the critically ill. As in any adaptation of evidence-based medicine, it is essential to closely examine the trials and to determine whether the demonstrated benefits can be translated to the individual patient. ⋯ Some of the interventions, such as small tidal volume mechanical ventilation in patients with acute lung injury or the administration of low-dose corticosteroids for patients with septic shock, are cost-effective and relatively simple to implement. Others, such as use of activated protein C in patients with severe sepsis or "tight" glycemic control in patients with hyperglycemia, require either significant pharmaceutical expenditure or, possibly, additional health care personnel. Nevertheless, the trials discussed represent significant advances in the field of critical care medicine and should at least be considered for implementation in all intensive care units.
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Anesthesia and analgesia · Aug 2004
Randomized Controlled Trial Clinical TrialThe effect of epidural clonidine on perioperative cytokine response, postoperative pain, and bowel function in patients undergoing colorectal surgery.
The postoperative period is associated with an increased production of cytokines, which augment pain sensitivity. We investigated the hypothesis that epidural clonidine premedication and postoperative patient-controlled epidural analgesia (PCEA) including clonidine would decrease the release of proinflammatory (interleukin (IL)-6, IL-1beta, IL-8, and tumor necrosis factor (TNF)-alpha) and antiinflammatory (IL-1 receptor antagonist (RA)) cytokines in patients who underwent elective colorectal surgery and that they would provide better postoperative analgesia. Forty patients were randomly assigned to 1 of 2 groups of 20 each: the control group received normal saline 10 mL, whereas the clonidine group received epidural clonidine 150 microg diluted with 9 mL of normal saline 30 min before surgery. ⋯ Patients in the clonidine group exhibited longer PCEA trigger times, lower pain scores at rest and while coughing, less morphine consumption, and a faster return of bowel function throughout the 72-h postoperative observation period, compared with patients in the control group. For patients in the clonidine group, production of IL-1RA, IL-6, and IL-8 was significantly less increased at the end of the surgical procedure and at 12 and 24 h after surgery. However, the concentrations of IL-1beta and TNF-alpha were not significantly increased.
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Anesthesia and analgesia · Aug 2004
Clinical Trial Controlled Clinical TrialThe effects of load on systolic mitral annular velocity by tissue Doppler imaging.
Tissue Doppler Imaging (TDI) provides information on systolic function through its systolic mitral annulus velocity wave (Sm), reflecting the peak velocity of shortening of the myocardial fibers oriented in the longitudinal direction. In this study, we evaluated the effect of load changes on Sm. Forty-two cardiac surgical patients with left ventricular ejection fraction >60% were consecutively evaluated. ⋯ The sample volume of TDI was placed at the lateral side of the mitral annulus in the mid-esophageal 4-chamber view. Changing loading conditions with phenylephrine or nitroglycerine had no effect on Sm; the increase of preload in 18 patients resulted in a statistically significant increase of Sm (baseline, 8.4 +/- 2.6 cm/s; after increase of preload, 9.6 +/- 2.5 cm/s; P = 0.001). We conclude that Sm is dependent on changes in preload obtained by volume loading and cannot be recommended as an index of ventricular contractile performance in critically ill patients where significant changes in ventricular filling occur.
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Anesthesia and analgesia · Aug 2004
Clinical TrialMaintenance of normoglycemia during cardiac surgery.
We used the hyperinsulinemic normoglycemic clamp technique, i.e., infusion of insulin at a constant rate combined with dextrose titrated to clamp blood glucose at a specific level, to preserve normoglycemia during elective cardiac surgery. Ten nondiabetic and seven diabetic patients entered the clamp protocols. Perioperative glucose control was also assessed in 19 nondiabetic and 11 diabetic patients (control group) receiving a conventional insulin infusion sliding scale. ⋯ Glucose concentration was recorded before surgery, 15 min before cardiopulmonary bypass (CPB), during early and late CPB, and at sternal closure. Patients of the control group became progressively hyperglycemic during surgery (late CPB; nondiabetics, 9.0 +/- 3.2 mmol/L; diabetics, 10.1 +/- 3.6 mmol/L), whereas normoglycemia was achieved in the study group (late CPB; nondiabetics, 5.5 +/- 0.7 mmol/L; diabetics, 4.9 +/- 0.6 mmol/L; P < 0.05 versus control group). In conclusion, it seems that normal blood glucose concentration during open heart surgery can be reliably maintained in nondiabetic and diabetic patients by using the hyperinsulinemic normoglycemic clamp technique.