thiopental and Arterial-Occlusive-Diseases

Postoperative platelet hyperaggregability following general anesthesia has been reported in patients undergoing major vascular surgery. In contrast, since anesthetic agents inhibited platelet function both in vitro and in vivo, an increased risk for postoperative bleedings due to prolonged platelet dysfunction has been discussed. Nevertheless, data describing platelet-affecting properties of induction agents such as etomidate and thiopental in patients undergoing major vascular surgery are lacking.. Platelet function was determined at 0, 2, 20, and 200 microg/ml thiopental and at 0, 0.2, 2, 20 microg/ml etomidate in vitro in blood samples drawn from 16 patients suffering from severe occlusive arterial disease. In addition, 30 patients undergoing vascular surgery were investigated before (PRE) and after anesthesia induction (T0) either with etomidate (ETO group, n=16) or thiopental (THIO group, n=14), and 2 h after the beginning of surgery (T2). Platelet function was determined according to platelet aggregation, in vitro bleeding time, and flow cytometric measurements.. In vitro, P-selectin expression was inhibited by etomidate at 2 and 20 microg/ml (-28% and -38%, respectively) and also by thiopental at 200 microg/ml (-27%). In patients undergoing vascular surgery, anesthesia induction in the ETO group resulted in a 31% prolongation of the in vitro bleeding time and an inhibition of ADP- and collagen-induced platelet aggregation (-30% and -17%, respectively) and of P-selectin expression (-25%) at T0. In the THIO group, only ADP-induced platelet aggregation was affected (-16%). At T2, all parameters had reached PRE level again in both groups. Furthermore, in comparison with the THIO group, operation time was significantly prolonged and transfusion volume was significantly increased in the ETO group. In addition, platelet count and hematocrit significantly decreased at T2, whereas levels of tPA, PAI-1, fibrinogen and antithrombin III and partial thromboplastin time remained unchanged in both groups during the study period.. In the present study, etomidate and, to a minor extent, thiopental offered significant platelet inhibitory properties. Anesthetic-induced platelet inhibition may lead to higher transfusion rates and prolonged operation times. Therefore, anesthetic-related platelet inhibitory properties should be considered when searching for the anesthetic agent of choice, especially in patients with compromised hemostasis and co-existing bleeding disorders.

Topics: Aged; Anesthetics, Intravenous; Arterial Occlusive Diseases; Bleeding Time; Double-Blind Method; Etomidate; Female; Fibrinogen; Hematocrit; Humans; Male; Middle Aged; P-Selectin; Platelet Aggregation; Platelet Count; Protein Binding; Thiopental; Vascular Surgical Procedures

Temporary interruption or reduction of cerebral blood flow during cerebrovascular surgery may rapidly result in ischemia or cerebral infarction. Thiopental has been shown to have cerebroprotective effects. However, the cerebroprotective dose of thiopental causes burst suppression of the EEG, thus this parameter cannot be used continuously for the detection of metabolic changes in the brain during thiopental anaesthesia. This study was performed in order to examine whether the multiparametric assembly (MPA), which measures energy metabolism CBF and mitochondrial (NADH) as well as extracellular ion concentrations (K+), can shed light on the mechanism of the cerebroprotective effects of thiopental. The MPA was placed on the brain of Mongolian gerbils and burst suppression of the ECoG was induced by thiopental. Cerebral ischemia was induced by occlusion of carotid arteries after burst suppression. Burst suppression of the ECoG was accompanied by a significant decrease in cerebral blood flow. In animals that received thiopental prior to ischemia, NADH increased to a lesser degree and extracellular potassium ion concentration increased to a lesser degree than in the control animals, indicating that thiopental affords protection of the brain under ischemic conditions due to improved energy metabolism. This study also demonstrates that the MPA can monitor changes occurring in the cerebral cortex even after the ECoG can no longer be used. Those findings have a significant value in the development of a new clinical monitoring device.

Topics: Animals; Arterial Occlusive Diseases; Brain Ischemia; Carotid Arteries; Cerebral Cortex; Cerebrovascular Circulation; Electroencephalography; Extracellular Space; GABA Modulators; Gerbillinae; Mitochondria; Neuroprotective Agents; Oxidation-Reduction; Potassium; Thiopental

Topics: Anesthetics; Arterial Occlusive Diseases; Carotid Artery Diseases; Fentanyl; Humans; Hypertension; Intracranial Aneurysm; Male; Middle Aged; Phenylephrine; Sufentanil; Thiopental

Pharmacologic protection should be used cautiously. The author reviews its rationale, use, and recommendations in three clinical conditions associated with ischemic brain damage: stroke, cardiac arrest, and head trauma.

Topics: Adult; Animals; Arterial Occlusive Diseases; Barbiturates; Brain Injuries; Brain Ischemia; Cats; Cerebral Arteries; Cerebrovascular Disorders; Dogs; Female; Heart Arrest; Humans; Intracranial Pressure; Male; Middle Aged; Models, Biological; Papio; Phenobarbital; Saimiri; Thiopental

Topics: Angiography; Animals; Arterial Occlusive Diseases; Arteries; Dexamethasone; Ear, External; Humans; Injections, Intra-Arterial; Rabbits; Reserpine; Thiopental; Tolazoline

This test has been previously described and is used routinely by the authors since 1960. The method is based on the alternate arterial blood distribution between skin and muscle of a limb, depending on modifications in the vasomotor tone. Skin temperature, arteriography and progression speed of the contrast medium are measured simultaneously. The test shows the morphology of the arterial lesion. It measures vasomotor reserve by these parameters, especially the skin temperature, before and after administration of pentothal. Results are rated as good, average and poor. The authors have compared this test, performed before surgery, to the results of lumbar sympathectomy and found an excellent correlation. Late result of lumbar sympathectomy can thus be foreseen by means of this test provided no new organic lesion interferes with the hemodynamics of the limb.

Topics: Angiography; Arterial Occlusive Diseases; Arteriosclerosis; Evaluation Studies as Topic; Humans; Leg; Regional Blood Flow; Skin Temperature; Sympathectomy; Thiopental