Study Objective: To test the hypothesis that slow administration of local anesthetic into the epidural space by gravity flow reduces the incidence of signs and symptoms of unintended injection.
Design: Prospective, randomized study.
Setting: Teaching hospital.
Patients: 600 ASA physical status I and II parturients scheduled for labor and delivery or elective cesarean section.
Interventions: After identification of the epidural space with pulsations of an air-fluid column, parturients for vaginal delivery (n = 380) were randomized to receive a test dose of 3 ml 3% 2-chloroprocaine with epinephrine 20 μg, two doses of 7 ml bupivacaine 0.03 % with sufentanil 1 μg/ml and epinephrine 2 μg/ml by either gravity flow (Group 1) given over 30 seconds or by bolus injection (Group 2) given over 5 seconds through the epidural needle; parturients for Cesarean delivery (n = 220) were randomized to receive a test dose and two doses of 6 ml lidocaine 2 % with sufentanil 1 μg/ml and epinephrine 2 μg/ml by either gravity flow or by bolus injection through the epidural needle. Changes in maternal heart rate (HR) and blood pressure, signs of intravascular injection, and adverse effects of epidural bupivacaine-sufentanil were recorded after each dose.
Measurements and Main Results: Gravity flow administration (Group 1) was associated with a smaller increase in mean maternal HR (p < 0.001), less hypotension (p < 0.01), sedation (p < 0.01), nausea (p = 0.01), and segmental spread (p < 0.0001) than were corresponding doses given by traditional bolus injection (Group 1) for vaginal or Cesarean deliveries. The incidence of systemic toxicity was zero of 300 (0%) with gravity flow and 4 of 300 (1.3%) by bolus injection, p = 0.12, Fisher's exact test. No patient in either group had an accidental intrathecal injection.
Conclusion: Gravity flow administration of local anesthetic-opioid solution during epidural block for obstetrics was associated with fewer signs of systemic drug absorption and cardiovascular perturbations than was the traditional bolus injection. This study supports the current opinion that slow administration of local anesthetic during epidural black contributes to fewer adverse events. 相似文献
A case of insulinoma is reported in a patient in whom selective arterial calcium injection (SACI) tests were performed both
to confirm tumor localization before surgery and to confirm complete tumor removal during surgery. An 18-year-old woman with
hypoglycemic episodes was diagnosed with an insulinoma in the pancreatic body demonstrated by celiac arteriography. In a preoperative
SACI test, calcium was injected into the splenic artery (SpA), gastroduodenal artery (GDA), and superior mesenteric artery
(SMA). Serum immunoreactive insulin (IRI) and proinsulin levels were measured in hepatic venous samples. IRI was markedly
increased after the injection of calcium into the GDA and SMA, while there was no response in IRI levels when calcium was
injected into the SpA. Therefore, no occult insulinoma was revealed in the distal area fed by the SpA, although the presence
of insulinoma was uncertain in the proximal pancreas. In the intraoperative SACI test, calcium was injected into the celiac
artery. Insulin (determined by enzyme immunoassay) and proinsulin levels were measured in portal venous samples before and
after resection of the tumor. After resection, these levels decreased in response to the calcium stimuli, confirming complete
removal of the insulinoma. The SACI test was helpful to localize the insulinoma and was useful to confirm the complete removal
of the tumor. 相似文献
Intrastriatal injection of the GABAA antagonist, bicuculline, caused about a 75% decrease in the inhibitory effect of the central-type benzodiazepine (BZ) agonist, clonazepam or the indoleamine hormone, melatonin, on apomorphine-induced rotation in a 6-hydroxydopamine model of dopaminergic supersensitivity. Pretreatment with the peripheral-type BZ antagonist, PK 11195 (intrastriatally or intraperitoneally), also attenuated the antidopaminergic effect of these drugs but with much less potency than bicuculline. However, the combination of both bicuculline and PK 11195, injected directly into the striatum, completely blocked the antidopaminergic action of clonazepam or melatonin. These results indicate that the antidopaminergic action of clonazepam and melatonin in the striatum involves two distinct mechanisms: (1) a predominant GABAergic activation via the BZ/GABAA receptor complex, and (2) a secondary mechanism linked to a PK 11195- sensitive BZ receptor pathway. Recent studies indicate that PK 11195 blocks BZ-induced inhibition of the adenylyl cyclase-cyclic AMP pathway in the striatum. Since cyclic AMP has been implicated in the rotational behaviour of 6-hydroxydopamine-lesioned animals, it is possible that the antidopaminergic action of clonazepam and melatonin also involves suppression of this second messenger. All rights reserved. 相似文献
To elucidate the penetrability of carteolol, a β-adrenoceptor antagonist (β-blocker) into the brain of rats, intracerebral
and serum concentrations of the compound were determined in male rats receiving single or repetitive oral administration of
carteolol hydrochloride at 30 mg/kg. The time-course of the intracerebral concentration of carteolol following single IV administration
of the compound at 10 and 30 mg/kg was also studied in male rats. A high-performance liquid chromatography method was used
to determine the intracerebral and serum concentrations. Following single oral dosing, the intracerebral concentration of
carteolol reached a maximum of 0.074 μg/g at 2 h postdosing and declined with a half-life of 3.7 h, and the Cmax and AUC of carteolol in the brain were 12.5% and 19.8% of those in serum. The intracerebral and serum concentrations of carteolol
were determined in male rats receiving repetitive oral dosing of the compound once daily for 7 days. The concentration of
carteolol in the brain and serum at 1 h postdosing varied within a range of 0.059–0.091 μg/g and 0.321–0.443 μg/ml, respectively,
throughout the dosing period, showing no changes in the penetrability of the compound into the brain due to repeated dosing.
The concentration of carteolol in the brain and serum increased in a dose-dependent manner in rats receiving a single IV administration
of the compound. The elimination half-life of carteolol in the serum and brain was 0.6–0.8 h and 1.3–1.7 h, respectively,
in rats following single IV dosing of the compound. The half-life in the brain was about twice as long as that in the serum.
The brain to serum concentration ratio was 0.306:0.499. From the above results, it was concluded that carteolol is distributed
from the circulation to the brain with low penetrability.
Received: 30 October 1996/Final version: 16 December 1996 相似文献
