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International audience; Nephrogenic diabetes insipidus due to the inability of the kidneys to concentrate urine is frequently observed during lithium therapy. Lithium concentrates into principal cells in collecting ducts in the kidney and downregulates aquaporin 2 expression, which reduces renal reabsorption of water. This disease is characterized by polyuria - polydipsia leading to intracellular dehydration and hypernatremia. Water deprivation test is performed to confirm insipidus diabetes. The desmopressin permits to distinguish nephrogenic from cranial insipidus diabetes. We report the case of a 64 years old women who presented with global dehydration and severe hypernatremia. Four years ago, she was hospitalized for nephrogenic diabetes insipidus related to a self-induced lithium intoxication. Persistent nephrogenic insipidus diabetes after cessation of lithium therapy are described in literature, and this hypothesis may be consistent with this case report.

Extreme hypernatremia in intensive care unit are frequently associated with a poor prognosis and their treatment, when associated with acute renal failure, is not consensual. We report the case of a 39-year-old man admitted in our intensive care unit for coma who presented extreme hyperosmolar hypernatremia (sodium 180 mmol/L, osmolarity 507 mOsm/L) associated with acute renal failure (urea 139.3 mmol/L, creatinine 748 μmol/L) and many other metabolic abnormalities. He was treated with hypotonic fluid administration and continuous renal replacement therapy (veno-venous hemodiafiltration) using an industrial dialysate fluid. Natremia was controlled by modulating intravenous water and sodium intake according to biological data. After 10 days, continuous renal replacement therapy was stopped and neurological exam was normal. Continuous veno-venous hemodiafiltration may be useful for treatment of extreme hypernatremia by allowing gradual correction of fluid and electrolyte disorders.

Hypernatremia is defined by a serum sodium concentration of more than 145 mmol/L and reflects a disturbance of the regulation between water and sodium. The high incidence of hypernatremia in patients with severe brain injury is due various causes including poor thirst, diabetes insipidus, iatrogenic sodium administration, and primary hyperaldosteronism. Hypernatremia in the intensive care unit is independently associated with increased mortality and complications rates. Because of the rapid brain adaptation to extracellular hypertonicity, sustained hypernatremia exposes the patient to an exacerbation of brain edema during attempt to normalize natremia. Like serum glucose, serum sodium concentration must be tightly monitored in the intensive care unit.

Drowning in sea water is an unusual cause of severe hypernatremia. We report the case of a 3.5-year-old boy who died 11h after drowning in sea water, with a serum sodium level of 178 mmoL/L. In this case, hypernatremia was aggravated by diarrhea and hyperglycemia with glycosuria. Usually, correction of acute hypernatremia must be quick and early, aiming at a reduction of serum sodium concentration of up to 1-2 mmoL per liter per hour.

Because of antidiuretic hormone (ADH) disorder on production or function we can observe dysnatremia. In the absence of production by posterior pituitary, central diabetes insipidus (DI) occurs with hypernatremia. There are hereditary autosomal dominant, autosomal recessive or X- linked forms. When ADH is secreted but there is an alteration on his receptor AVPR2, it is a nephrogenic diabetes insipidus in acquired or hereditary form. We can make difference on AVP levels and/or on desmopressine response which is negative in nephrogenic forms. Hyponatremia occurs when there is an excess of ADH production: it is a euvolemic hypoosmolar hyponatremia. The most frequent etiology is SIADH (syndrome of inappropriate secretion of ADH), a diagnostic of exclusion which is made after eliminating corticotropin deficiency and hypothyroidism. In case of brain injury the differential diagnosis of cerebral salt wasting (CSW) syndrome has to be discussed, because its treatment is perfusion of isotonic saline whereas in SIADH, the treatment consists in administration of hypertonic saline if hyponatremia is acute and/or severe. If not, fluid restriction demeclocycline or vaptans (antagonists of V2 receptors) can be used in some European countries. Four types of SIADH exist; 10 % of cases represent not SIADH but SIAD (syndrome of inappropriate antidiuresis) due to a constitutive activation of vasopressin receptor that produces water excess. c 2013 Published by Elsevier Masson SAS.

Electrolyte disturbances are frequent after brain injuries, especially dysnatremia and dyskalemia. In neurological patients, usual clinical signs of hyponatremia are frequently confounded with clinical signs of the underlying disease. Natremia absolute value is less important than speed of onset of the trouble. Most often, hyponatremia is associated with hypotonicity and intracellular hyperhydration, which may exacerbate a cerebral edema. Distinction between inappropriate secretion of antidiuretic hormone (SIADH) and cerebral salt wasting syndrome (CSWS) may be difficult and is mainly based on assessment of patient's volemia, SIADH being associated with normal or hypervolemia and CSWS with hypovolemia. After subarachnoid haemorrhage, the most common disorder is CSWS. In this case, fluid restriction is strictly prohibited. Treatment of CSWS needs to compensate for the natriuresis and may justify the use of mineralocorticoid. It is important to avoid excessively rapid correction of hypernatremia, with a maximal speed of correction of 0.5 m mol/l/h. Serum sodium monitoring should be mandatory for the first ten postoperative days after pituitary adenoma surgery. Therapeutic barbiturate may be responsible for life threatening dyskalemia.

Hypernatremia is defined as a serum sodium concentration above the upper laboratory reference range, usually145 mmol/l. It is a common electrolyte disorder in the very young and the very old patient. Hospitalization itself is a risk factor for developing hypernatremia. Free water deficit is the main cause of this condition. It induces hyperosmolality and an intracellular dehydration. Clinical manifestations are mostly neurological but non-specific. A blood sample analysis is needed to establish the diagnosis. Hypernatremia is associated with a high mortality and morbidity. Treatment consists of correcting the underlying cause and the volume deficit. A brief review of this condition is proposed.

The authors report an 11-day-old exclusively breast-fed female, with a birth weight of 3 300 g, who had suffered from dehydration stage I, with acute renal failure and metabolic acidosis, with 170 mmol/L of serum sodium. Renal ultrasounds were normal but the rate of sodium in mother's milk was three times higher than controls (87 versus 21 mmol/L). Intravenous rehydration allowed the correction of hydroelectrolytic disorders.

Hypernatremia exerts its main effect on the brain through the osmotic gradient it creates on either side of the blood brain barrier, which is impermeable to sodium. This generates a transfer of water from the intracellular to the vascular sector leading to temporary cell shrinkage. Osmoregulation permits cerebral cells to accumulate osmoactive molecules in order to restore their initial volume. It has been demonstrated in animals with brain injury that intracellular dehydration occurs essentially in the nonlesioned hemisphere. In most experimental studies, the reduction in cerebral volume obtained by hypertonic saline (HS) perfusion is accompanied by an intracranial pressure decrease, even under hemorrhagic shock conditions. Initially, clinical studies successfully used HS, as an alternative to mannitol, in the treatment of acute and refractory intracranial hypertension. Then continuous infusion of HS, with the objective of inducing hypernatremia, had produced encouraging effects on intracranial pressure control. However, these results were limited to non-randomized studies, without control groups and mainly in pediatric patients. Nevertheless, the use of HS on intracranial hypertension, refractory to conventional treatments, could be reasonable under strict monitoring of natremia as well as its adverse effects.

A 55-year-old woman with bipolar disorder who had been taking lithium for several years developed hyperosmolar coma following osteosynthesis of a hip fracture. The coma was attributed to decompensation of undiagnosed nephrogenic diabetes insipidus due to chronic lithium intake. The lengthy perioperative fasting and large fluid loading (necessitated by the anesthetic technique) led to acute hypernatremia. Closer monitoring and a different anesthetic strategy might have avoided this classical complication of chronic lithium therapy. The patient recovered after symptomatic treatment. We discuss the perioperative management of patients taking (or having taken) lithium, based on a review of the literature.

The hypernatremic dehydration defined by a serum sodium concentrationor = to 150 mmol/l, is a particular form of acute dehydration and constitutes a medical emergency requiring a prompt and adequate diagnosis and management.To precise the epidemiological profile, course, causes and therapeutic particularities of hypernatremic dehydration in children.Retrospective review of 105 children admitted in the general Paediatrics department of the Fattouma Bourguiba university hospital in Monastir (Tunisia), for hypernatremic dehydration between January 1st 1990 and December 31 2002.Hypernatremic dehydration represented 11.51% of all kinds of dehydration. The mean age was 6.5 months with a small male predominance. The socio-economic level of the parents was good in 62.8% of cases. Half of the children were in shock. Severe dehydration was present in 87.6% of cases and neurological signs were observed in 77.14% of cases. The initial mean serum sodium concentration was 159 mmol/L. Acidosis and acute renal failure were associated respectively in 97.2% and 76.2% of cases. Prominent cause of hypernatremic dehydration was diarrhoea (94.3%). Intravenous rehydration with 5% glucose solution at the average of 147 ml/kg/day and containing a mean sodium level of 42 mmol/L was performed in 74% of cases. In most cases (84.1%) serum sodium was normalized within the first 72 hours. Complications were noted in 5.7% of cases and mortality rate was 11.4%.Hypernatremic dehydration was common in infant and the prominent cause is still dominated by diarrhoea in our country. The management of hypernatremic dehydration is based on oral or intravenous rehydration and plasma expanding fluids when shock is present or imminent. The serum sodium concentration should be gradually corrected and should not exceed 0.5 mmol/L/h. Prevention is based on the pursuit of breastfeeding and the use of oral rehydration solution in infantile diarrhoeas.

We studied elderly patients admitted for hyperosmolar state (HS) to evaluate current outcome of HS and identify prognosis factors associated with mortality.A clinical retrospective study in an eight bed ICU.Eighteen over 65-year-old patients admitted with a serum osmolality greater than 325 mOsm/kg were reviewed. Age, sex, diabetes mellitus, underlying medical condition, presence of an acute precipitating factor, Apache II and Glasgow scores, systolic arterial pressure, state of hydration, core temperature, heart rate, serum osmolality, creatininemia, lactatemia, plasma urea and bicarbonate, and protidemia were collected at the admission. Amount of fluid, time course of osmolality correction, length of hospitalization and mortality were recorded. All data were analyzed to identify possible correlations with patient outcome.Mean age: 75 +/- 11 years; sex ratio 1/2; hyperosmolar hyperglycemic states: 13 patients; hyperosmolar hypernatremic states: five patients; mean Apache II score: 18 +/- 7; Glasgow coma score: 11 +/- 3; mean osmolality: 370 +/- 25 mOsm/kg. In nine patients, infection was the precipitating factor. Five patients died (28%). At the admission, low blood pressure and high heart rate were related to mortality. During hospitalization, the occurrence of an acute cardiocirculatory failure and/or the need of mechanical ventilation significantly worsens the outcome.Our results showed that ICU mortality of HS in the elderly was at 28%. Haemodynamic state was the only factor of prognosis at the admission. Deaths were mostly related to acute respiratory and circulatory failure.

Neonatal hypernatremic dehydration due to breast feeding was rarely reported in the French-language literature.The authors report hypernatremic dehydration in a 10-day-old exclusively breast-fed infant. The course was favorable. Insufficient breast milk production has been reported for 30 years.Early discharge from maternity units is frequent nowadays. Breast-fed newborns without a positive weight gain at discharge should be checked for their weight within the first ten days of life.

Plasma sodium concentration, or natremia, results from three main factors: exchangeable sodium (Na+), exchangeable potassium (K+) and total body water (H2O). Its alterations often imply a change in cell volume. Understanding dysnatremias is essential for the treatment and prevention of hydromineral disorders. Extra-cellular fluid tonomoles consist almost exclusively of Na+ salts. Their dilution is the tonicity. K+ is an essential tonomole for intra-cellular fluid tonicity. The balance between intra and extracellular tonicities depends on water movements and is responsible for changes in intra- and extracellular fluid volumes. Cell volume is therefore depending on the tonicity balance. A change in body tonicity (which is not osmolality) can be correctly and rapidly appreciated by measuring the (Na+ + K+) and H2O balances. Clinical cases emphasize the misleadings resulting from the free-water clearance calculation or the only measurements of urinary losses. They also demonstrate that tonicity balance provides indications for therapy whereas analyses based upon electrolyte-free water do not. Intakes should be quantified with the same care than losses. The units used must be coherent to allow a quick and easy understanding at the bedside. Tonicity balance should be taught and Na+ + K+ and H2O balances should be routinely utilized by practitioners, dieticians and nurses in the concerned pediatrics, in particular intensive care, internal medicine, nephrology, pediatry and anesthesiology.

Hypernatraemia is defined as an increase in extracellular sodium concentration, associated with plasma hyperosmolality and cellular dehydration. It can result from excessive water loss, from an increase in the total sodium content or from both mechanisms. As far as neurosurgical pathology is concerned, hypernatraemia due to excessive water loss may be observed in patients who do not sense thirst or are unable to ingest water. Urinary water loss is seen in diabetes insipidus and osmotic diuresis. Extrarenal water losses from pulmonary origin may be observed in intubated or tracheotomized patients. Hypernatraemia with sodium and water retention may be encountered in patients suffering from Cushing diseases or syndromes, or more frequently in those who are given excessive amounts of sodium (hypertonic saline, sodium salts). Clinical manifestations of hypernatraemia consist of neurologic symptoms related to cellular dehydration; their severity is correlated with the rapidity of the onset of the electrolytic disorder. Depending on the pathophysiological mechanism, treatment of hypernatraemia involves stopping sodium intake, restoring normovolaemia and administering hypotonic fluids. Treatment of diabetes insipidus relies on the administration of the antidiuretic hormone and of drugs that increase its secretion rate or its responsiveness in the kidneys.

Hypernatremia in young adults is a rare condition, sometimes occurring after gastrointestinal diseases, osmotic diuresis or diabetes insipidus. The clinical characteristics and prognosis of hypernatremia in geriatric patients would be different. Each case must be examined separately.We conducted a prospective uncontrolled study among patients over 70 with sodium levels equal to or greater than 150 mmol/l (at admission or during the hospitalization).Hypernatremia was found in 77 patients. Mean age was 84.1 +/- 6.7 years. The mean peak serum sodium level was 157.3 +/- 7.4 mmol (two-thirds ranged from 150 to 160). Hypernatremia onset was produced by a wide range of symptoms: 48% had a febrile illness, 470% were on diuretics, 15% had had a stroke, but only 9% were suffering from diarrhea or vomiting. Most of the patients had disabling chronic illnesses (62% loss of two or more ADL of Katz), severe dementia (84% level = 6 on the Reisberg global deterioration scale). In spite of fluid replacement and follow-up treatment, outcome was poor: 62% of the patients died within three months.Besides digestive and renal losses, hypernatremia in elderly patients is increased by fluid supply disorders consecutive to hypodipsia contracted at the same time as disability and dementia. Hypodipsia is a sign of poor prognosis. Prevention must be undertaken early, emphasizing the importance of identifying dehydration early among elderly people with chronic disabling illnesses.

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. However, the response of the vasopressinergic axis to dehydration is greater in young rats, suggesting a more pronounced sensitivity to osmotic factors.

Semi-lobar holoprosencephalies can be seldom complicated by neurogenic hypernatremia, which must be distinguished from other causes of hypernatremia.In two admitted children with semi-lobar holoprosencephaly, 7 months and 4 years old, biological data revealed chronic hypernatremia and hyperosmolarity without clinical signs of dehydration, which were finally attributed to a neurogenic hypernatremia.Neurogenic hypernatremia must be clearly differentiated from other causes of hypernatremia since it never causes specific complications.

Sodium retention is the most common renal abnormality of cirrhosis and eventually leads to the formation of ascites. There is now a strong body of evidence that the arterial vasodilatation, mainly splanchnic, that occurs during liver cirrhosis is a major factor in the pathogenesis of renal sodium and water retention. The arterial vasodilatation and the subsequent hypotension stimulate a baroreceptor-mediated neurohormonal vasoconstrictor and antinatriuretic response in a attempt to compensate the relative underfilling of the circulation. The cause of the arterial vasodilatation is thought to be a circulating factor and several recent studies have implicated an excessive vascular production of nitric oxide (NO). In animal models of cirrhosis administration of NO antagonists corrects the hyperdynamic circulation and improves renal sodium excretion. The treatment of sodium retention is often difficult in liver cirrhosis and it is possible that the identification of a vasodilator substance which can be inhibited could provide a new tool in the therapeutic approach of sodium and water retention in cirrhosis.

Several cases of hypernatremic dehydration complicated by consumption coagulopathy and peripheral gangrene have been reported.A 4.5 month-old boy was admitted suffering from acute gastroenteritis with cyanotic edema of the distal part of the left leg and foot. His serum sodium was 160 mEq/l, potassium 5.8 mEq/l and urea 27.6 mMol/l. His prothrombin level was 44%, fibrinogen 0.65 g/l and the number of platelets was 20,000/mm3. Blood cultures were negative. Ultrasonography showed a subperiostal effusion in the posterolateral part of the left tibia with edema of the adjacent soft tissues. Culture of the fluid was negative. The patient was rehydrated. Several phlyctenes appeared on the left foot; cultures of the exudate remained sterile. His condition gradually normalized within two weeks and ultrasonography performed at the 15th day was normal.The subperiostal effusion seen in our patient could have been due to microthrombosis of the metaphyseal vessels, following severe dehydration.

A modification of serum osmolarity induces always movements of water across cell membranes and therefore variations of cell volume of all tissues, including brain. To avoid a severe cell dehydration or hyperhydration, the organism has several regulation means called osmoregulation. Cerebral osmoregulation is essential as the brain is contained in a unexpandable box. In comparison with other organs, this phenomenon is complex and particular as: 1) cerebral volume consists of 3 sub spaces (intracellular, extracellular and cerebrospinal fluid [CSF]); 2) exists a blood-brain barrier (BBB) which behaves functionally as a semi-permeable membrane, essentially sensitive to osmolar disturbances. This brain volume regulation mechanism is working whatever the nature of the solutes initiating the osmotic deviation (sodium, glucose, mannitol...). Cerebral osmoregulation results from intracerebral osmolar modifications. Thus, every variation of plasma osmolarity elicits a similar variation of intracerebral osmolarity. This phenomenon results from modifications of the brain cell "protective" osmoles content. When the osmolar disturbance occurs quickly (in a few hours), cerebral osmoregulation is not complete. It results essentially from modifications of brain cell inorganic solutes content, i.e. electrolytes (Na, K, Cl) which originate from plasma, CSF and extracellular brain spaces uptake. When the osmolar disturbance is more progressive, cerebral osmoregulation is complete. The brain volume returns then to its initial value, by increasing its brain cell electrolytes, but above all organic "idiogenic" osmoles content. These idiogenic osmoles are identified as amino acids, polyols and trimethylamines. During treatment, the delayed normalization of brain osmolarity compared with plasma osmolarity prescribes a slow correction of the osmolar disturbance, as much as it is a chronic one.

Netherton's syndrome is characterized by ichthyosis, trichorrhexis invaginata and other air shaft anomalies, and atopic diathesis. The ichthyosis is present at birth and can be complicated by hypernatremic dehydration.Adrien was the first child of non-consanguineous parents. His birth weight was 3,110 g. Ichthyosis was present at birth and the diagnosis of Netherton's syndrome was subsequently confirmed by skin biopsy. He was admitted to intensive care at the age of 4 days for a 20% loss of weight and dehydration. His blood chemistry was: Na+ = 192 mmol/l; K+ = 6.9 mmol/l; Cl- = 136 mmol/l; urea = 21 mmol/l; glucose = 12.1 mmol/l; creatinine = 209 mumol/l; hematocrit = 51%. Urinary analysis gave: Na+ = 113 mmol/l; K+ = 97 mmol/l; urea = 105 mmol/l. Progressive rehydration resulted in normal diuresis 24 hours later and a slow normalization of natremia to 138 mmol/l on day 10. Despite preventive i.v. phenobarbital, he developed convulsions on day 5 when his natremia was 177 mmol/l i.e. after a drop of 0.6 mmol/hour. The convulsions disappeared when he was given phenytoin and placed on respiratory support, but status epilepticus appeared on day 18 with normal natremia. This status epilepticus was not influenced by several antiepileptic drugs and was only cured when the patient was given tetracosactide followed by hydrocortisone plus sodium valproate. Adrien is now 3 years old and is neurologically and mentally normal.Hypernatremic dehydration can be a complication of neonatal ichthyosis; it may be severe with very high blood sodium concentration. Corticosteroids can be useful for treating persistent convulsions.

Data concerning 9 cases of Netherton's syndrome (NS) have been collected from 6 French dermatology units (table I). Analysis of these data has confirmed the information previously published, notably the prevalence of congenital ichthyosis erythroderma (CIE) as cutaneous manifestation in the neonatal period (77 p. 100), hair shaft dysplasia being rarely found at that stage (11 p. 100). In the majority of cases (5/9 in our series), CIE evolves in adults as ichthyosis linearis circumflexia (ILC), with trichorrhexis invaginata (TI) as the predominant hair shaft dysplasia. These data are in agreement with the diagnostic elements laid down by Dupré and Traupe. Some points may have been underestimated in the past. They include: hypernatraemic dehydration in the neonate; short stature and low weight (unrelated to endocrine disorders; mental and neurological retardation possibly associated with seizures. Various manifestations of hypersensitivity have been noted in 26 p. 100 of the published cases and in 6 of our 9 patients. The aggravating role played by hypersensitivity may be considered in some cases. NS must be regarded as a broad-spectrum disease the margins of which could be isolated skin manifestations in ILC and ichthyosis erythroderma with various associated disorders in cases with severe illness.

The authors report a case of hypernatremic dehydration following chronic water deprivation and very likely salt load as a form of child abuse in a 2 11/12 year-old girl. This uncommon picture often expresses a severely disturbed relationship between parents and child which has to be considered in the family management.

Numerous experimental studies on the effects of hypertonic saline in haemorrhagic shock have been published and controlled clinical studies are now beginning to be reported. Animals suffering from an otherwise lethal haemorrhagic shock survived when given hypertonic sodium chloride solution (7.5%, 2,400 mosmol.1-1). In most studies, this solution was more efficient than isotonic fluids in treating controlled haemorrhage. Although the mechanisms involved are not yet fully understood, they certainly include the following: 1) plasma volume expansion due to osmotic fluid shifts into the vascular compartment from intra- and extra-cellular fluid reservoirs, as hypertonic saline induces hypernatraemia and hyperosmolarity, both effects linked to the sodium load; 2) non specific precapillary vasodilation of renal, coronary and splanchnic vessels; 3) arterial and venous vasoconstriction in muscle and skin, due to a vagal reflex set off by the lung osmoreceptors, the efferent pathway of which is likely to be the sympathetic nervous system; 4) increased myocardial contractility. Hypertonic saline also decreases intracranial pressure, and improves lung function during resuscitation of haemorrhagic shock. However, hypertonic saline should not yet be used routinely in man, except in controlled clinical studies. Indeed, there are as yet not enough data concerning humans. Moreover, during uncontrolled haemorrhage, hypertonic saline increased blood pressure, and therefore bleeding, thus reducing survival rates. Further clinical studies are required before hypertonic saline could be safely recommended for treatment of haemorrhagic shock.