The effect of the cholinergic blocker, scopolamine on the cerebral blood flow (CBF) response to vibrotactile stimulation of a fore paw was studied using high-resolution positron emission tomography and H215O in 5 pentobarbital-anesthetized cats. Before scopolamine injection, the CBF response to the stimulation was found in the contralateral somatosensory cortex (mean ratio (contralateral/ipsilateral) control: stimulated1.02 ± 0.02: 1.17 ± 0.05; P < 0.01). After intravenous injection of scopolamine (0.35 mg/kg), the CBF response was abolished. However, the cerebral metabolic rate of glucose (CMRGlu) response to the same stimulation was unchanged after scopolamine injection in the same cats. We concluded that scopolamine abolishes the CBF response but not neuronal response to stimulation. We suggest that cholinergic mechanisms may play an important role for mediating CBF coupling to neuronal activity during physiological stimulation. 相似文献
We assessed the local cerebral blood flow (LCBF) in 40 patients under fentanyl-diazepam anesthesia. The measurement of LCBF
was made using 50%–70% stable xenon with 20 min of inhalation interval and a shuttle method for computed tomography imaging.
All patients were anesthetized with 5.95±1.76 μg·kg−1 fentanyl and 0.22±0.07 mg·kg−1 diazepam under mechanical ventilation during CBF measurement. The values and distribution of LCBF on non-affected hemisphere
appeared to be unaltered by fentanyldiazepam anesthesia. We also assessed the cerebral carbon dioxide reactivity in 6 patients.
The cerebral carbon dioxide reactivity, expressed as percentage change in LCBF per unit change in arterial carbon dioxide
partial pressure, was 5.39±1.07, and there were no significant differences of reactivity among regions studied. In conclusion,
we showed reference values of LCBF and carbon dioxide reactivity, measured by stable xenon-enhanced computed tomography, in
patients under fentanyl-diazepam anesthesia. Carbon dioxide reactivity was preserved in all regions including gray matter,
white matter, and basal ganglia. 相似文献
Background Many centers use local anesthesia for adult inguinal hernia surgery in the setting of day-case surgery. There are no reports
on, or guidelines for, use of anesthesia for inguinal hernia surgery in adolescents. We describe our initial experience with
the use of local anesthesia and intravenous sedation for inguinal hernia surgery in adolescents in the setting of a day-surgery
facility.
Methods The charts of 14 consecutive adolescent patients (aged 12–17) who had inguinal hernia surgery from July 2004 to March 2005
were reviewed retrospectively. Intravenous sedation was administered 1–3 min before injection of local anesthetic. Sedation
consisted of midazolam 0.085 mg kg−1 and either fentanyl 0.85 μg kg−1 or ketamine 0.085 mg kg−1, according to the preference of the anesthesiologist. Additional sedation with half the initial dose was administered if
required. Local anesthesia using a combination of lignocaine and bupivacaine was administered by the surgeon with infiltration
in the skin and deep tissues.
Results Fourteen adolescents aged 12–17 years (mean 14.8 ± 1.37), weighing 34–100 kg (mean 61.2 ± 16.5), had 15 inguinal hernia repairs
with sedation and local anesthesia. All the patients were male. All completed the surgery with sedation and local anesthesia.
None required conversion to general anesthesia. There were no immediate or subsequent complications. Mean time from the end
of surgery to discharge home was under 2 h (mean 106 ± 36 min). Examination of patient charts did not reveal any complaints
regarding the surgery or the postoperative course at the postoperative follow up visit.
Conclusions The use of local anesthesia with intravenous sedation for inguinal hernia repair in the adolescent age group seems feasible
and requires further prospective study. 相似文献
Study Objective: To compare the volatile anesthetic sevoflurane with halothane, enfurane, and isof urane on the uptake and biotransformation in humans.
Design: Prospective pharmacokinetic study of sevofurane administration in human subjects.
Setting: Inpatient surgery clinic at a university medical center.
Patients: Thirty-two Japanese patients, free of systemic diseases, undergoing minor elective surgery with endotracheal general anesthesia.
Interventions: The patients were assigned randomly to one of four groups: halothane, enflurane, isofurane, or sevofurane. One of the four volatile anesthetics being investigated [equivalent to 1.1 minimum alveolar concentration (MAC): halothane, 0.85%; enfurane, 1.85%; isofurane, 1.27%; and sevofurane, 1.88%; in inspired concentrations throughout the first hour of anesthesia] was administered for 60 minutes.
Measurements and Main Results: In all patients, serum and urinary fluoride concentrations were measured. The concentrations of all gases were measured separately with a mass spectrometer. The cumulative uptake of each anesthetic agent during a certain period was calculated as an integration of the uptake rate per minute. The results for one-hour inhalation of sevofurane (1.1 MAC) showed an uptake (corrected for body surface area and MAC) of 490 ml/m2/MAC and estimated degradation rate of 3.3%. For purposes of comparison, similar studies of halothane (uptake, 653 ml/m2/MAC; degradation rate 15.7%), enfurane (1150 ml/m2/MAC; 1.3%), and isofurane (439 ml/m2/MAC; 0.6%) were also conducted. Sevofurane had a peak serum inorganic fluoride concentration of 19.3 μmol/L, and no abnormality in hepatic or renal functions was observed in any of the subjects during the two weeks postoperatively.
Conclusions: Accurate determinations of uptake and degradation rate for sevoflurane and three other volatile anesthetics in Japanese patients were obtained. These findings have established that, despite its relatively large MAC *1.71%), sevoflurane has a small uptake due to its low solubility. However, the degradation rade was shown to be as high as 3.3%, resulting in a higher serum fluoride concentration than seen after administration of isoflurane, halothane, and (possibly) enflurane. 相似文献