Hitchcock's original method of hypothermic subarachnoid irrigation employed both temperature and osmolarity. Spinal cooling was then abandoned in favour of intrathecal injection of normothermic hypertonic salilne. Modifications of the procedure that followed have continued to accept hyperosmolarity as the factor causing pain relief. Fifty patients were treated by a technique evolved to enhance ...

The effect of blood injected into either subarachnoid space or subcortical brain tissue upon lactate and pyruvate concentrations as well as acid-base balance of cerebrospinal fluid (CSF) was studied in the anesthetized dog. CSF lactate and lactate/pyruvate ratio (L/P ratio) increased progressively following the intracranial injection of blood and reached the maximum level at six hours after inj...

Rat and mouse were utilized as models to study the spinal (subarachnoid) anesthetic effects of five commonly used local anaesthetic agents. Duration and frequency of motor and sensory blockade, and onset time were determined after injection of 5.0% lignocaine, 0.75% bupivacaine and 1.0% amethocaine to the same groups of rats with chronically implanted catheters in the lumbar subarachnoid space....

Cerebral blood flow was measured by a [14C]butanol indicator fractionation technique in rats subjected to subarachnoid hemorrhage, in control rats, and in rats given injections of buffered saline into the subarachnoid space (sham hemorrhage). Cerebral blood flow was significantly decreased in both the subarachnoid hemorrhage and sham hemorrhage rats 3 hours after injection. However, blood flow ...

Precise in vivo evaluation of cerebral vasospasm caused by subarachnoid hemorrhage has remained a critical but unsolved issue in experimental small animal models. In this study, we used synchrotron radiation angiography to study the vasospasm of anterior circulation arteries in two subarachnoid hemorrhage models in rats. Synchrotron radiation angiography, laser Doppler flowmetry-cerebral blood ...

The absorption of the nonionic contrast medium iohexol, the clearance tracer 51Cr-ethylenediaminetetraacetic acid, and the blood-pool marker 125I-human serum albumin was studied after subarachnoid and subdural injection in rabbits. Subdural deposition of the contrast medium and 51Cr-ethylenediaminetetraacetic acid resulted in a faster absorption rate and higher achieved blood levels than a suba...

Sir,—Elliott, Voyvodic and Brownridge recently reported an unexpected subarachnoid block in a parturient, despite careful aspiration testing and prior administration of local anaesthetic via a catheter, presumably located in the lumbar extradural space. 1 We recently described five similar cases of high spinal block produced by the initial test dose alone after negative aspiration testing. 2 We...

Acute vasospasm of the transclivally exposed basilar artery of anesthetised cats was produced by the subarachnoid injection of platelet-rich plasma (PRP) treated with enough adenosine diphosphate (ADP) to induce platelet aggregation and secretion. Vasorelaxation was produced by the topical application of the calcium antagonist verapamil. Changes in the internal diameter of the basilar artery we...

1. Rabbits which have received a single dose of normal horse serum in the subarachnoid space produce precipitins in the blood in greater abundance, of higher titer, and persisting longer than those in control rabbits which have received a similar injection intravenously. 2. Repeated subarachnoid injections of normal horse serum in rabbits induce precipitins in the blood early. These may appear ...