Plasmatic osmolality

A clinical trial was conducted to compare the efficacy of a low-osmolarity solution (245 mOsm/L), and a standard oral rehydration solution (ORS) recommended by WHO for children dehydrated by diarrhea. Group 1 (69 children) received WHO/ORS (311 mOsml/L) and group 2 (71 children) received a low-osmolarity solution (245 mOsm/L). Rehydration was successful in 88.4% in group 1 and 92.9% in group 2 (p = 0.35). Rehydration was completed in 5.2 h (SD +/- 1.8) in group 1 and 5.5 (SD +/- 1.7) in group 2 (p = 0.31). Stool output was 6...

PURPOSE: To investigate the influence of two non-ionic radiographic contrast media with different osmolality on thrombocytic function and the plasmatic coagulation system. MATERIAL AND METHODS: The study was carried out as a randomised, prospective, comparative study with two contrast media in a heart catheter laboratory. RESULTS: Activating influences on platelet aggregation, procoagulatory or profibrinolytic functions or injury to the endothelium could be ruled out...

Under normal physiological conditions, the osmolarity of extracellular fluids (ECFs) and natremia are controlled by two regulatory mechanisms modulating the water balance and sodium outflow from information collected by the osmoreceptors and baroreceptors, respectively. As well, under normal physiological conditions, water and electrolytes of brain ECFs are secreted by the endothelial cells of brain capillaries. Furthermore, isotonicity is present on both sides of the blood-brain barrier. In the event of systemic osmolarity disorders, water transport subject to osmosis laws occurs at the level of the blood-brain barrier...

The aim of our work was to study the different blood parameters as well as the activity of the vasopressinergic axis in young and mature male rats under normal conditions and following a 3-day dehydration cycle by water deprivation. Under normal conditions, our study demonstrates higher levels of vasopressin in mature rats as compared to young rats. This could be due in part to the higher blood osmolality in the mature rats. After dehydration, hypovolemia, plasmatic hyperosmolality, hypernatremia and hyperproteinemia cause a stimulation in vasopressin synthesis and release, as seen in results obtained from the hypothalamus, hypophysis and plasma in both young and mature rats...

In a healthy human being, the extracellular volume is kept constant by homeostatic systems. One of these is represented by the antidiuretic hormone (ADH). ADH release is modulated by osmoreceptors and baroreceptors which respond to an increase in osmolality of extracellular fluid and a decrease in blood volume, respectively. In previous studies we investigated the existence of additional structures sensitive to plasma volume modifications. We found evidence of the presence of such receptors in the inner ear, with nervous connections to supraoptic and paraventricular nuclei...

Persistence of nocturia after prostatic resection in healthy patients without symptoms referred to residual bladder instability and to pathological polyuria seems to be caused by an increased urine production at night. The more accreditate mechanism involved is the relevant decreased ADH secretion pattern which occurs at night. In our study, patients with nocturnal poliuria showed significantly low plasmatic vasopressin levels compared with a control group. The aim of this study was to evaluate whether the persistence of nocturia after prostatic resection in healthy patients, without symptoms referred due to residual bladder instability and important polyuria, could be due to a decrease or a lack of increase in antidiuretic hormone (ADH) nocturnal levels following increased urine production at night...

In uremic patients during chronic hemodialysis an increase in the volume of red blood cells is observed. Contemporaneously there is an increase in intraerythrocytic ornithynedecarboxylase activity beyond the normal content (P < 0.01), a high level of seric and plasmatic polyamines (P < 0.01) and a decrease in seric osmolality (P < 0.01) with pH improvement. The trends of osmolality, ornithynedecarboxylase, mean cell volume and pH are significantly related. Our data support the hypothesis that, during hemodialysis, red blood cell volume changes and increased ornithynedecarboxylase activity are dependent on the general improvement of plasma tonicity...

OBJECTIVE: To determine whether furosemide could prevent renal side effects of indomethacin (INN, indometacin) used for the pharmacologic closure of the patent ductus arteriosus (PDA) in preterm infants. METHODS: Thirty-six preterm infants with birth weights < 1750 gm affected by hemodynamically significant PDA were randomly assigned to one of two study groups. Group 1 consisted of 18 infants treated with three doses of indomethacin (0.20 mg/kg every 12 hours); each dose was followed by a dose of furosemide (1 mg/kg)...

The properties of the endothelium differ between the brain and the remainder of the body. In most non-CNS tissues the size of the junctions between endothelial cells averages 65 A. Proteins do not cross these gaps, while sodium does. In the brain, the junction size is only 7 A, which is too small to allow crossing by sodium. Investigations with changes in osmotic and oncotic pressure have demonstrated that: (1) reducing osmolality results in edema formation in all tissues including normal brain; (2) a decrease in oncotic pressure is only associated with peripheral edema but not in the brain; (3) in case of brain injury, a decrease in osmolality elicits edema in the part of brain which remained normal; (4) similarly, a decrease in oncotic pressure does not cause an increase in brain edema in the injured part of the brain...

Research has been carried out on 55 subjects suffering from Menière's disease; 15 patients showed plasmatic hyperosmolality (300 mOsm./1. or more) and 6 of them were in a vertiginous attack. Statistical calculations have shown significant differences between the numbers of patients with hyperosmolality during a crisis and after one.

Plasma arginine vasopressin (AVP) was measured in 24 patients with polyuria exceeding 3.5 l/day diagnosed as severe or partial diabetes insipidus according to the dehydration test. All patients with severe diabetes insipidus diagnosed by the dehydration test had very low or undetectable basal AVP values and always subnormal plasma osmolality. Patients with partial diabetes insipidus diagnosed by the dehydration test had a wide range of AVP and osmolality values. The stimulation test performed on these patients was able to differentiate patients with primary polydipsia from patients with partial diabetes insipidus...

The effect of acetazolamide was assessed in 25 patients with Menière's disease. During the test session hearing threshold and plasmatic osmolality were monitored along with fluctuations in hearing loss, fullness, tinnitus and balance. A single, 250 mg dose of acetazolamide was administered to all patients via os early in the morning on an empty stomach. Hearing was tested prior to administration and every hour for five hours thereafter. Plasmatic osmolality was also assessed during the same session. In 52% of this group an improvement in the threshold was seen...

1. The osmotic fragility, the concentrations of Na, K and Ca, the osmolality and the total ATPase activity of bovine erythrocytes from uninfected and Anaplasma marginale-infected bovines were studied in an attempt to correlate these parameters with the decrease in the cellular ATP concentration reported during bovine anaplasmosis. 2. The osmotic fragility found in infected bovine erythrocytes, at 0.52% NaCl, was about two times greater than that observed in non-infected bovines. The increase in osmotic fragility was directly related to the increase in intra-erythrocytic parasitemia...

We report two cases of unexplained hyperkalaemia during infusion of amino acid solutions enriched with branched chain amino acids. The increase in potassium levels developed 24 hours after starting infusion and normalization was obtained within 24 hours after stopping infusion. Acidosis, acute renal failure, concomitant cell destruction and haemolysis were excluded; antialdosteronic diuretics were not given. The authors hypothesize that hyperkalaemia could be due to a sudden increase in plasmatic osmolality caused by the hyperosmolarity (900 mOsm/l) of the solution, not counterbalanced by adequate ADH release owing to malfunctioning of hypothalamic osmoreceptors...

The syndrome of inadequate secretion of antidiuretic hormone (SIADH) following treatment with a tricyclic antidepressant is demonstrated using the example of a 70 year-old man admitted for weakness and cognitive disturbances. Because of incontinence he had been periodically treated since 1989 with imipramine (Tofranil) by his family doctor. On admission he was seriously hyponatriemic and had low plasmatic osmolality, significantly lower than urinary osmolality. Creatinine, urea and uric acid in serum were also below normal values...

The administration of ehtanol by gavage immediately produced a maintened hyperdiuresis, a transient decrease of urinary osmolality and antidiuretic hormone secretion, followed by increased plasmatic and urinary antidiuretic hormone concentrations. Chronic intoxication enhanced these effects probably due to central disturbance.

A study was performed on 30 patients diagnosed antomopathologically for malignant neoplasia of the lung (epidermoid carcinomas, adenocarcinomas, oat-cell carcinomas, and neoplasias which could not be definitely classified). The following parameters for blood and urine were determined: osmolality, sodium, potassium, urea, and creatinine. Osmotic free water, creatinine, sodium, and potassium clearances were also calculated, as well as the plasma osmolality/urinary osmolality ratio. The basic aim of our study was to investigate for the presence of disturbances in the metabolism of water and alterations in plasmatic and urinary osmolality in this type of tumor...