BACKGROUND Patients with postural tachycardia syndrome (POTS) experience considerable disability, but in most, the pathophysiology remains obscure. Plasma volume disturbances have been implicated in some patients. We prospectively tested the hypothesis that patients with POTS are hypovolemic compared with healthy controls and explored the role of plasma renin activity and aldosterone in the reg...

Hyponatremia is an important electrolyte abnormality with the potential for significant morbidity and mortality. Common causes include medications and the syndrome of inappropriate antidiuretic hormone (SIADH) secretion. Hyponatremia can be classified according to the volume status of the patient as hypovolemic, hypervolemic, or euvolemic. Hypervolemic hyponatremia may be caused by congestive h...

Base deficit has frequently been utilized as an informal adjunct in the initial evaluation of trauma patients to assess the extent of their physiologic derangements. However, the current Advanced Trauma Life Support (ATLS) classification system for hypovolemic shock does not include base-deficit measurements and relies primarily on alterations in vital signs (heart rate, systolic blood pressure...

Background Dengue can cause increased vascular permeability that may lead to hypovolemic shock. Endothelial dysfunction may underlie this; however, the association of endothelial nitric oxide (NO) pathways with disease severity is unknown. Methods We performed a prospective observational study in 2 Vietnamese hospitals, assessing patients presenting early (<72 hours of fever) and patients hos...

INTRODUCTION Isolated vital signs (for example, heart rate or systolic blood pressure) have been shown unreliable in the assessment of hypovolemic shock. In contrast, the Shock Index (SI), defined by the ratio of heart rate to systolic blood pressure, has been advocated to better risk-stratify patients for increased transfusion requirements and early mortality. Recently, our group has developed...

BACKGROUND The infusion of small volumes of hypertonic saline solution or hypertonic saline plus dextran 70 is remarkably effective in restoring adequate hemodynamic conditions after hypovolemic shock. This prospective double-blind study compares the immediate hemodynamic effects of a bolus infusion of 7.5% NaCl or 7.5% NaCl plus 6% dextran 70 (both 2400 mOsm/L) in severe hypovolemia. METHODS...

CD1 mice injected peripherally with either ANG I or ANG II failed to drink substantial amounts of water or NaCl, yet showed strong Fos immunoreactivity (ir) in subfornical organ (SFO). Mice injected with furosemide showed modest stimulation of NaCl intake either 3 or 24 h later, were hypovolemic, and showed elevated plasma renin activity (PRA). The pattern of Fos-ir in the brain after furosemid...

BACKGROUND Estimation of volume status in the high-acuity surgical population can be challenging. The use of intensivist bedside ultrasound (INBU) to rapidly assess volume status in the surgical intensive care unit (SICU) was hypothesized to be feasible and as accurate as invasive measures. METHODS Clinician sonographers (CSs) were trained to perform basic cardiac ultrasound and sonographic a...