0000000000135418
AUTHOR
J. P. Jantzen
Deliberate Arterial Hypotension Does Not Reduce Intraocular Pressure in Pigs
Among the accepted advantages of general anesthesia in ophthalmic surgery is improved control of intraocular pressure (IOP). Although standard textbooks advocate deliberate arterial hypotension to facilitate intraocular surgery by reducing IOP, scientific proof of such an effect is lacking. The authors investigated effects of induced arterial hypotension on IOP in an anesthetized porcine model. Forty-two piglets were anesthetized with piritramide, were placed in the prone position, and had the anterior chamber of one eye punctured with a small Teflon cannula to measure IOP. Six pigs were used in a pilot study to establish dose-response relationships for the hypotensive agents; 36 pigs were …
Tissue elastance and fluid conduction in normotensive and hypertensive intracerebral mass haematomas.
This is an investigation into the prognostic factors of 117 patients with spontaneous normo- and hypertensive intracerebral haematomas, supported by animal experiments. Preserved tissue elastance and fluid conduction enables the drainage of intrinsic haematoma serum into the CSF spaces in normotensive patients, who showed an increased extension of a perifocal hypodensity in the CT. Arterial hypertension decreased the possibility of fluid resolution. Our experimental studies showed that in hypertensive cases the serum remained trapped in the haematoma, which explains the small hypodense area around the haematoma in most of the hypertensive cases. If as an exception in hypertensives of perifo…
Pathomechanism of Brain Oedema in Experimental Intracerebral Mass Haemorrhage
The prognosis of intracerebral haemorrhage is extremely poor when arterial hypertension is present. We investigated elastance of the brain tissue and brain hydraulic conductivity in normotensive (MAP ~ 110 mmHg) and hypertensive (MAP ~ 170 mmHg/angiotensin infusion) cats following a stereotactically produced intracerebral haemorrhage. For 12 hours after the onset of haemorrhage we registered the course of ICP, subsequently the water content of cortex, white matter and basal ganglia as well as the interstitial concentration of serum proteins in the corresponding regions were determined (Evans-Blue, immunofluorescence). Hypertension was associated with a slight increase in ICP and tissue wate…
ICP- and IOP-Effects of Deliberate Hypotension Using Urapidil
Deliberate hypotension is an accepted method to facilitate certain neurosurgical and intraocular procedures. The rationale is to reduce transmural pressure on arterial vessels and thus to facilitate preparation of cerebrovascular aneurysms and malfunctions — or in ophthalmology to reduce the risk of expulsive bleeding (Jantzen and Earnshaw 1988).