Sodium nitroprusside (SNP) hypotension: intracranial pressure (ICP) and hemodynamics in pial arteriole in the rat.

A detailed description is made of an acute closed cranial window method. The method is used for the study of cerebral pial microcirculation by intravital microscopy in the rat. Using these methods and techniques, the effects of systemic hypotension by SNP, i.

Cortisol and antidiuretic hormone responses to stress in cardiac surgical patients.

The hormonal responses to anaesthesia and cardiac surgery were studied in patients undergoing valve or coronary bypass surgery. Marked increases in antidiuretic hormone levels as a result of surgical stress were seen, and were of approximately equal magnitude in both groups. Although both groups also showed marked increases in plasma cortisol levels in response to operations, this response appeared to be relatively blunted in valve surgery patients, especially at the end of operation and in the intensive care unit.

The effect of endotoxin on microcirculatory and lymphatic dynamics in the rat (Shwartzman phenomenon).

Observations and measurements of the responses of the rat's microcirculation and lymphatics during the Shwartzman reaction showed that (1) greater increases in arteriolar activity and more rapid derangement of capillary and postcapillary venular walls were induced by the Shwartzman phenomenon than by a single dose of endotoxin; (2) the hyperdynamic state persisted with the first dose of endotoxin but hypotensive low flow syndrome followed a delayed second administration of endotoxin; (3) the lymphatic contractile activity which was depressed with an initial dose also became hyper-reactive with the subsequent dose; (4) both the blood vessels and the lymphatics became hypersensitive to sympathomimetic amines. The pattern of events simulate the pattern seen during clinical endotoxin shock.