Assessment of Neurological Toxicity of Hydroxyethyl Starch 130/0.4 Injected in the Intrathecal Space in Rats.

Objective: Epidural blood patch is the procedure of choice to relieve postdural puncture headache. Hydroxyethyl-starch (HES) has been proposed as a patch in some circumstances such as in the case of hematological disease due to the theoretical risk of neoplastic seeding to the central nervous system. Acute neurological HES toxicity has been excluded by a previous animal study, but the long-term neurological toxicity has not been evaluated.

Neurotoxicity of intrathecal 6% hydroxyethyl starch 130/0.4 injection in a rat model.

Epidural blood patch is the gold standard treatment for post-dural puncture headache, although hydroxyethyl starch may be a useful alternative to blood if the latter is contraindicated. The aim of this experimental study was to assess whether hydroxyethyl starch given via an indwelling intrathecal catheter resulted in clinical or histopathological changes suggestive of neurotoxicity. The study was conducted in rats that were randomly allocated to receive three 10-μl injections on consecutive days of either saline or hydroxyethyl starch administered via the intrathecal catheter.

Role of calcium in the rate-dependent depression of atrioventricular nodal conduction in the dog heart under vagal influence.

Increase in heart rate may be detrimental to atrioventricular conduction. The effects of such an increase were investigated in the paced intact dog heart, by measuring the conduction time in the atrioventricular node (obtained from the His bundle potential recording) and the effective refractory period in this node as determined by the extrastimulus method. Investigations on atrioventricular nodal conduction were performed with and without vagal influence.

Modification of atrioventricular conduction under the combined influence of a cardiac glycoside and a calcium antagonist in the dog.

Conduction disorders may be logically expected from the digoxin-verapamil association, since each of these drugs is known to increase conduction time (CT) and effective refractory period (ERP) in the atrioventricular (AV) node. When AV conduction is considerably depressed by verapamil (1.27 mg/kg over 90 min) in the absence of vagal tone, digoxin, infused at 1 microgram/kg/min rate over 40 min, elicits a progressive but incomplete regression of the verapamil effects, as does hypercalcaemia up to 5.

Protection against ventricular and atrial fibrillation by sotalol.

Sotalol is not only a beta blocker but a class III antiarrhythmic drug. Its possible antifibrillatory activity was therefore investigated in both the ventricles and atria of dog heart in situ, since vulnerability to fibrillation is not the same in both these parts of the myocardium. Fibrillation threshold was measured concurrently with the duration and amplitude of monophasic action potential, the effective refractory period, the conduction time in the contractile fibres, and after fibrillation had been triggered the fibrillation rate.