4 Clinical Trials for Various Conditions
Hyponatremia, defined as a serum sodium \< 135 mmol/l, in patients without edema has undergone significant changes where it is now evident that even mild hyponatremia should be treated because of its association with symptoms, especially a fourfold increase in falls over the age of 65 years. There is an unresolved controversy over the relative prevalence of the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) and cerebral/renal salt wasting (C/RSW). Resolution of this diagnostic dilemma becomes urgent because of divergent therapeutic goals, to water-restrict in SIADH or to give salt and water supplementation in C/RSW. The dilemma is compounded by recent reports of C/RSW occurring in patients without cerebral disease, thus adding further confusion in defining the relative prevalence of both syndromes. Because of overlapping laboratory and clinical findings in both syndromes, only differences in the state of extracellular volume differentiates one syndrome from the other, being high normal to increased in SIADH and decreased in C/RSW. The investigators have used fractional excretion (FE) of urate to categorize patients with hyponatremia. The increased FEurate that is observed in hyponatremic patients with SIADH and C/RSW can be used to differentiate both syndromes by correcting the hyponatremia and determining whether FEurate normalizes as in SIADH or remains increased in C/RSW. The present studies have been designed to determine total body water by deuterium and extracellular water by sodium bromide in patients with nonedematous hyponatremia with normal and increased FEurate to differentiate more conclusively whether the patient has normal or decreased water volumes. The investigators will also correct serum sodium rapidly with judicious administration of hypertonic saline over approximately three days and determine whether FEurate normalizes as in SIADH or remains increased as in C/RSW. In another group of patients, The investigators have data to suggest that those with normal sodium and increased FEurate is consistent with C/RSW. The investigators intend to do the same water volume studies to determine whether an increased FEurate with normonatremia would have decreased total and extracellular water that these patients have C/RSW without the need to correct a prior hyponatremia.
To assess the pharmacokinetic profile of tolvaptan in critically ill acute brain injury patients and to secondarily evaluate the clinical response and safety of tolvaptan in acute brain injured patients
Subarachnoid hemorrhage (SAH) occurs after rupture of cerebral aneurysms. Treatment of SAH focuses on avoiding medical complications including cerebral vasospasm, which may result in limited circulation to the brain. Cerebral vasospasm, or thinning of the arteries of the brain, is a feared complication that could potentially cause stroke and worst outcomes after SAH. Hypertonic saline (HTS) is a compound that may be used to prevent vasospasm following SAH by enhancing the circulation in the brain. This study will evaluate if a protocol of volume expansion with HTS is safe and effective in patients with subarachnoid hemorrhage for the prevention of cerebral vasospasm.
Hypothesis: Tolvaptan will improve cognitive function, brain edema and health-related quality of life in cirrhotic patients with hyponatremia