Anesthesia and analgesia
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Anesthesia and analgesia · Sep 2003
Randomized Controlled Trial Clinical TrialThe effect of nitrous oxide on cerebrovascular reactivity to carbon dioxide in children during propofol anesthesia.
Nitrous oxide (N(2)O) increases cerebral blood flow when used alone and in combination with propofol. We investigated the effects of N(2)O on cerebrovascular CO(2) reactivity (CCO(2)R) during propofol anesthesia in 10 healthy children undergoing elective urological surgery. Anesthesia consisted of a steady-state propofol infusion and a continuous caudal epidural block. ⋯ We conclude that N(2)O does not affect CCO(2)R during propofol anesthesia in children. When preservation of CCO(2)R is required, the combination of N(2)O with propofol anesthesia in children would seem suitable. The cerebral vasoconstriction caused by propofol would imply that hyperventilation to ETCO(2) values less than 35 mm Hg may not be required because no further reduction in cerebral blood flow velocity would be achieved.
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Anesthesia and analgesia · Sep 2003
Randomized Controlled Trial Comparative Study Clinical TrialHemispheric synchronized sounds and intraoperative anesthetic requirements.
Hemispheric synchronization is currently promoted as a treatment for preoperative anxiety and for reduction of intraoperative anesthetic and analgesic consumption. We designed this study to examine the effect of Hemisync sounds on anesthetic hypnotic depth. After obtaining informed consent, we randomized subjects undergoing general anesthesia and outpatient surgery into two groups: the treatment group received Hemisync sounds (n = 31), and the control group received a blank cassette tape (n = 29). ⋯ We found no differences in the amount of propofol used during the induction of anesthesia (2.49 +/- 0.59 mg/kg versus 2.60 +/- 0.59 mg/kg; P = 0.48) or the maintenance of anesthesia (0.141 +/- 0.02 mg x kg(-1) x min(-1) versus 0.146 +/- 0.04 mg x kg(-1) x min(-1); P = 0.62) between the Hemisync and control groups. We also found no differences between the Hemisync group and the control group for participants with high state anxiety (P = not significant). We conclude that Hemisync sounds do not reduce the hypnotic component of the anesthetic state of patients undergoing general anesthesia and surgery.
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Anesthesia and analgesia · Sep 2003
Case ReportsContinuous paravertebral catheter and outpatient infusion for breast surgery.
Paravertebral somatic nerve block (PVB) provides improved analgesia and decreased side effects compared with general anesthesia for breast surgery. The analgesia is limited with single injection PVB to the duration of the local anesthetic. ⋯ We describe the successful use of continuous paravertebral anesthesia in two patients undergoing major breast surgery. A novel needle system for paravertebral catheter insertion is also presented.
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Anesthesia and analgesia · Sep 2003
Case ReportsSuccessful resuscitation after ropivacaine-induced ventricular fibrillation.
Human data about resuscitation after cardiac arrest from ropivacaine are limited. We present a case of successful cardiopulmonary resuscitation after accidental ropivacaine-induced ventricular fibrillation. A 76-yr-old female patient presented for foot osteotomy. ⋯ The patient was admitted to the hospital and discharged the next morning without complications. This case demonstrates that techniques used to detect intravascular injection may reduce but not eliminate catastrophic events. Consequently, regional anesthesia using large amounts of local anesthetic should be done in locations with resuscitation equipment and by individuals trained to recognize these complications and begin early treatment.
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Anesthesia and analgesia · Sep 2003
Doxapram produces a dose-dependent reduction in the shivering threshold in rabbits.
Dopamine is a thermoregulatory neurotransmitter that provokes hypothermia when injected in or near the hypothalamus. Doxapram stimulates release of dopamine from carotid bodies, but is known to have central effects that are probably, at least in part, similarly mediated. We thus tested the hypothesis that doxapram produces a substantial, dose-dependent reduction in the shivering threshold in rabbits. ⋯ The control rabbits shivered at 36.3 degrees +/- 0.3 degrees C, those given 0.25 mg x kg(-1) x h(-1) doxapram shivered at 34.8 degrees +/- 0.5 degrees C, and those given 0.50 mg x kg(-1) x h(-1) shivered at 33.7 degrees +/- 0.6 degrees C. All the shivering thresholds significantly (P < 0.001) differed from one another. The magnitude of this inhibition, if similar in humans, would be clinically important.