Anesthesia and analgesia
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Anesthesia and analgesia · Jul 2006
Hyperchloremic acidosis in the critically ill: one of the strong-ion acidoses?
Decreases in plasma bicarbonate are associated with hyperchloremic acidosis and lactic acidosis. According to the Stewart approach to acid-base physiology, the strong-ion difference regulates plasma bicarbonate, with chloride and lactate being the only strong anions routinely measured in clinical chemistry. We hypothesized that the plasma strong-ion difference, both with and without lactate, would have a stronger association with plasma bicarbonate than plasma chloride alone would have with bicarbonate. ⋯ We conclude that hyperchloremic acidosis and lactic acidosis are strong-ion acidoses. Hyperchloremia should be viewed relative to the plasma strong cations. A practical conclusion is that both managing and preventing acid-base disorders with IV fluid therapy involves manipulating each of the plasma strong ions, particularly sodium and chloride.
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Anesthesia and analgesia · Jul 2006
Randomized Controlled TrialThe use of dexmedetomidine in pediatric cardiac surgery.
We tested dexmedetomidine, an alpha2 agonist, for its ability to decrease heart rate, arterial blood pressure, and neuroendocrinal responses during pediatric cardiac surgery. In a randomized, placebo-controlled study, 30 pediatric patients undergoing open heart surgery were randomly assigned to one of two equal groups. The control group received saline, whereas the treatment group (DEX group) received an initial bolus dose of dexmedetomidine (0.5 microg/kg) over 10 min, followed immediately by a continuous infusion of 0.5 microg.kg(-1).h(-1). ⋯ In both groups, plasma cortisol, epinephrine, norepinephrine, and blood glucose increased significantly relative to baseline, after sternotomy, and after bypass. However, the values were significantly higher in the control group compared with the DEX group (P < 0.05). In conclusion, intraoperative dexmedetomidine infusion attenuated the hemodynamic and neuroendocrinal response to surgical trauma and cardiopulmonary bypass in pediatric patients undergoing corrective surgery for congenital heart disease.
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Anesthesia and analgesia · Jul 2006
Clinical TrialAnesthetic considerations for magnetic seizure therapy: a novel therapy for severe depression.
Electroconvulsive therapy (ECT) is a highly effective treatment for severe depression. However, its use is associated with significant posttreatment cognitive impairment. Magnetic seizure therapy (MST) was developed as an alternative therapy that could reduce postseizure side effects through the induction of more "focal" seizure activity. ⋯ The Hamilton depression rating scale score was significantly reduced from the baseline value in both treatment groups; however, the posttreatment score was lower after the series of ECT treatments (6 +/- 6 versus 14 +/- 10; P < 0.05). We conclude that MST was associated with a decreased requirement for muscle relaxants, reduced variability in the BIS values after seizure induction, and a more rapid recovery of cognitive function compared with ECT. Further studies are required to evaluate the antidepressant efficacy of MST versus ECT when they are administered at comparable levels of cerebral stimulation.
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Anesthesia and analgesia · Jul 2006
General anesthesia and chronic amphetamine use: should the drug be stopped preoperatively?
Prescription amphetamines are being used more often for several medical conditions. Anesthesia concerns focus on the cardiovascular stability of patients who may be catecholamine-depleted and thus have a blunted response to intraoperative hypotension. Previously we reported one case of a patient receiving chronic amphetamine therapy who had a stable intraoperative course. ⋯ All required general anesthesia for their surgical procedures and 6 of the 8 patients were tracheally intubated. Anesthesia operating room times ranged from 30 min to 4.25 h. The authors conclude that amphetamine use need not be stopped before surgery and anesthesia.
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The risk of postoperative nausea and vomiting (PONV) is reduced in cigarette smokers by unknown mechanisms. If protection is related to an acute effect of smoke constituents, smokers with the most recent exposure to cigarette smoke would be most protected. We tested the hypothesis that in cigarette smokers, postoperative nausea is correlated with recent exposure to cigarette smoke as quantified by exhaled carbon monoxide (CO) concentrations. ⋯ Significant correlations were found between nausea assessed over the first 24 h postoperatively and a history of PONV or motion sickness, the use of intraoperative antiemetic prophylaxis, duration of anesthesia, and use of opioids in the postanesthesia care unit. However, there was no correlation between preoperative CO and nausea over the first 24 h. These preliminary data suggest that the effect of smoking in reduced PONV is not directly related to preoperative exhaled CO levels.