Journal of anesthesia
-
Journal of anesthesia · Jun 1994
Differential effects of isoflurane, halothane, and ketamine on the regional methionine-enkephalinlike immunoreactivity in the mouse brain.
The widely used measurement index for anesthetic potency, minimum alveolar concentration (MAC), is hypothesized to be the sum of the effects on multiple neural systems whose contribution to anesthesia differs depending on the agents used. The present study, which compared the effects of halothane, isoflurane, and ketamine, at equipotent level of anesthesia, on the methionine-enkephalinergic neurons in 9 brain regions, showed a significant difference in the methionine-enkephalin-like immunoreactivity (Met-ENK-like IR) among the anesthetics in each region. The order of the Met-ENK-like IR was: halothane > ketamine > isoflurane in the caudatus putamen; halothane > isoflurane ≊ketamine in the nucleus accumbens and the ventral pallidum; halothane ≊isoflurane > ketamine in the globus pallidus, the nucleus dorsomedialis hypothalami, and the nucleus ventromedialis hypothalami; and halothane > isoflurane > ketamine in the arcuate nucleus, the periaqueductal gray, and the nucleus reticularis parvocellularis. These findings indicate that these three anesthetics affect the methionine-enkephalinergic neurons in the motor and pain controlling pathways in different fashions.
-
Journal of anesthesia · Jun 1994
Differential effects of vecuronium on the thumb and the big toe muscles evaluated by acceleration measurement.
To clarify the differential effects of vecuronium on the thumb and on the big toe, train-of-four (TOF) stimuli were applied to the ulnar nerve at the wrist and the tibial nerve at the ankle in anesthetized patients using two acceleration transducers. Ten adult patients, aged 21-55 years, were studied. Anesthesia was induced by an intravenous injection of thiopental, and vecuronium 0.1 mg·kg-1 was used for paralysis. ⋯ The duration of time to the maximal twitch depression on the thumb and the big toe was 136.5±32.5 s and 183.0±40.1 s (P<0.05), respectively. The time to 25% recovery of the twitch height on the thumb and the big toe was 48.1±17.3 min and 39.1±11.6 min, respectively; the time to 50% recovery of twitch height on the thumb and the big toe was 54.1±16.1 min and 40.0±9.2 min (P<0.05), respectively. When paralysis was reversed at 25% of TOF ratio on the thumb, the value of the TOF ratio on the big toe was 58.5±18.2% (P<0.01).
-
Journal of anesthesia · Jun 1994
Left ventricular diastolic filling during coronary artery bypass surgery in patients with diabetes mellitus and/or hypertension.
To evaluate left ventricular diastolic filling (DF) using transesophageal Doppler echocardiography in 40 patients with or without diabetes mellitus and/or hypertension, we measured DF after induction of anesthesia, before and after cardiopulmonary bypass (CPB), and at the end of coronary artery bypass surgery (CABS). In 13 patients with complete measurements, there was no significant change in DF but diastolic filling time became shorter and peak velocity during atrial contraction increased significantly following CPB. ⋯ When heart rate (HR) was more than 75 beats·min-1 (RR interval of less than 800 ms), the incidence of fusion points was significantly higher in patients with diabetes and/or hypertension than without (13 of 29s 1 of 9,P<0.05). It is suggested that a slower HR (less than 75 beat·min-1) is desirable in CABS patients with these disorders to avoid impairment of DF due to either prolonged systolic time or isovolumic relaxation time.
-
Journal of anesthesia · Jun 1994
Comparison of bupivacaine and fentanyl as an adjuvant of epidural morphine for postoperative analgesia.
We conducted a retrospective study to determine whether bupivacaine or fentanyl is a better adjuvant to epidural morphine for postoperative analgesia using 108 patients. Following epidural lidocaine anesthesia with or without light general anesthesia for major gynecological surgeries, 59 patients received epidural morphine (EPM) 2 mg (group M), 21 patients received morphine 2 mg plus 0.25% plain bupivacaine 6-10 ml epidurally (group B), and 28 patients received morphine 2 mg plus fentanyl 100 μg epidurally (group F). ⋯ The incidence of adverse effects was similar among all three groups. In conclusion, fentanyl appears to be a better adjuvant to epidural morphine than bupivacaine.
-
Journal of anesthesia · Jun 1994
Administration of MgSO4 failed to improve the neurological recovery after complete global brain ischemia in dogs.
The cerebral protective effects of MgSO4 after complete global brain ischemia were evaluated with EEG, evoked potentials (EP) and the neurological recovery score (NRS) in the dog. Complete global brain ischemia for 15 min was achieved by occluding the ascending aorta and the caval veins. The MgSO4 group (N=7) were injected with a 10% MgSO4 solution and the control group (N=7) were administered a normal saline intravenously from the beginning of the resuscitation to 48 h after ischemia. ⋯ The NRSs (0=death, 100=normal) in the control group and the MgSO4 group were 50±3 (n=7) and 43±9 (n=7) on the 3rd day after ischemia, and were 56±5 (n=5) and 42±12 (n=5) on the 7th day. The differences between the two groups were not significant. We conclude that MgSO4 administered after ischemia has no beneficial effects on the recovery of EEG, EP and the NRS after 15 min of complete global brain ischemia in the dog.