Disorders of sodium metabolism: hypernatremia and hyponatremia

Extremely Severe Hypernatremia Caused by Wrong Belief in a Patient with Cervical Cancer

A 56-year old female patient who was undergoing follow-up for cervical cancer in our oncology center was presented to the emergency center with anxiety and excessive thirst. The initial serum sodium level of the patient exceeded 200mEq/L, rising up to 238mEq/L during hospitalization. The extremely severe hypernatremia was caused by patient's wrong belief that bay salt would cure the cancer. The patient was treated with hypotonic solution and finally with appropriate hydration, she was fully recovered without any neurological complications.

Thrombosis secondary to acute hypernatraemia after liver hydatid cyst surgery

Hypernatraemia after hypertonic saline irrigation of a hepatitic hydatid cyst is a rare but serious complication. Neurological symptoms and signs are frequently seen in hypernatraemia. However, other symptoms, such as fever, acute pulmonary oedema, congestive cardiac failure and muscular alterations, may appear. It has recently been suggested that hypernatraemia increases the risk of thrombosis.We present the first report of an adult patient who survived a severe acute iatrogenic hypernatraemia and hyper-coagulability resulting from hypertonic saline irrigation of intra-abdominal hydatid cysts.

Efficacy of conivaptan and hypertonic (3%) saline in treating hyponatremia due to syndrome of inappropriate antidiuretic hormone in a tertiary Intensive Care Unit

Background:

Hyponatremia is one of the most common electrolyte abnormalities encountered in clinical practice and has a significant impact on morbidity and mortality in hospitalized patients. The optimal management of hyponatremia is still evolving. Over the last decade, vaptans have been increasingly used in clinical practice with promising results.

Materials and Methods:

The study included eighty patients with symptomatic hyponatremia due to syndrome of inappropriate antidiuretic hormone (SIADH) admitted and treated in Intensive Care Unit (ICU) with either conivaptan or hypertonic (3%) saline. They were compared for time taken to achieve normal serum sodium, length of ICU and hospital stay, and adverse effects.

Results:

The demographic data and serum sodium levels at admission were comparable between the two groups. After initiating correction, sodium levels at 6, 12, and 24 h were similar between the two groups. However, at 48 h, patients in the conivaptan group (Group C) had higher sodium levels (133.0 ± 3.8 mEq/L) as compared to hypertonic saline group (Group HS) (128.9 ± 2.6 mEq/L), which was statistically significant (P < 0.001). The length of ICU stay was less in the Group C (3.35 ± 0.89 days) when compared with the Group HS (4.61 ± 0.91 days) (P < 0.001). There was no significant difference in mortality between the two groups.

Conclusion:

In patients with symptomatic hyponatremia due to SIADH, conivaptan with its aquaresis property can achieve a significantly better sodium correction, resulting in reduced ICU and hospital stay with no significant adverse effects.

Prevalence of hyponatremia in intensive care unit patients with brain injury in kashan shahid-beheshti hospital in 2012

Background

Hyponatremia is a common disorder in patients with brain injury. It can result in acute and chronic complications providing this electrolytic disorder is not diagnosed and treated in due time.

Objectives

The aim of this study was to evaluate the prevalence of hyponatremia in 95 brain injury patients hospitalized in the intensive care unit (ICU) in Kashan Shahid-Veheshti hospital.

Patients and Methods

This trans-sectional study was conducted on brain injury patients (brain traumas, brain hemorrhage, meningitis and brain tumors) during their six-month stay in the ICU in Kashan Shahid-Beheshti hospital. Data were analyzed after excluding cases of pseudohyponatremia.

Results

Ninety-five patients with brain injury (69.5% male and 30.5% female ( had a mean age of 42.85 ± 22.59 years, while the hyponatremic patients had a mean age of 48.37 ± 24.03 years. Prevalence and occurrence of hyponatremia were 31.6% and 9.29 ± 6.8 days, respectively. This study revealed no meaningful differences between age, sex, underlying disease and the prevalence of hyponatremia.

Conclusions

Our study showed an elevated frequency of hyponatremia in patients with brain injuries in ICU which demands the effective approaches for an accurate and timely diagnosis of this electrolyte disorder.

Hypernatremic Disorders in the Intensive Care Unit

Hypernatremia, defined as plasma sodium concentration >145 mEq/L, is frequently encountered in critically ill patients admitted to the intensive care unit (ICU). Hypernatremia indicates a decrease in total body water relative to sodium and is invariably associated with plasma hyperosmolality though total body sodium content may be normal, decreased, or increased. Hypernatremia usually occurs as a result of impaired thirst or access to water, with or without increased water losses from renal and extrarenal sources. Critically ill patients in ICU are at high risk of hypernatremia because of their inability to control free water intake as a result of sedation, intubation, change in mental status, and fluid restriction for various other reasons. In addition, excessive fluid losses from various renal or nonrenal sources and treatment with sodium containing fluids are commonly encountered in this population, predisposing them to hypernatremia. The consequences of hypernatremia result from osmotic movement of water across the cell membrane, leading to primarily intracellular and variable degree of extracellular volume depletion. The clinical features depend on severity and rapidity of hypernatremia development with abnormal cognitive and neuromuscular function in many cases and potential risk of hemorrhagic complications or death from vascular stretching and rupture in advanced cases. The management of hypernatremia focuses on judicious replacement of free water deficit to restore normal plasma osmolality as well as identification and correction of underlying causes of hypernatremia. Electrolyte-free water replacement is the preferred therapy though electrolyte (sodium) containing hypotonic fluids can also be used in some circumstances. Oral free water replacement guided by thirst is ideal though parenteral fluid replacement is usually necessary in critically ill ICU patients. Various calculations for estimating free water deficit are available and any can be used to guide initial fluid replacement therapy. Rate of correction depends on rapidity of hypernatremia development, though frequent monitoring of plasma sodium levels is essential to ensure appropriate response and to adjust the rate of fluid replacement to prevent the risk of cerebral edema from rapid correction of chronic hypernatremia. Free water requirements should be routinely assessed in ICU patients and judicious electrolyte and free water replacement prescribed for those at risk of hypernatremia.

Sodium Disturbances Commonly Encountered in the Neurologic Intensive Care Unit

Disorders of sodium and water balance are common in patients with central nervous system (CNS) disease. These disorders frequently complicate the treatment course by precipitating or worsening neurological symptoms. These patients are not only at risk for symptoms secondary to dysnatremia but also at risk from the consequences of treatment. If not treated properly, this electrolyte disturbance can vastly increase morbidity and can even lead to death. Appropriate diagnosis and intervention requires an understanding of the physiologic and pathophysiologic mechanisms involved in sodium and water homeostasis.

Hyponatremia in neurosurgical patients: clinical guidelines development

OBJECTIVE

Neurosurgical patients have a high risk of hyponatremia and associated complications. We critically evaluated the existing literature to identify the determinants for the development of hyponatremia and which management strategies provided the best outcomes.

METHODS

A multidisciplinary panel in the areas of neurosurgery, nephrology, critical care medicine, endocrinology, pharmacy, and nursing summarized and classified hyponatremia literature scientific studies published in English from 1950 through 2008. The panel's recommendations were used to create an evaluation and treatment protocol for hyponatremia in neurosurgical patients at the University of Florida.

RESULTS

Hyponatremia should be further investigated and treated when the serum sodium level is less than 131 mmol/L (class II). Evaluation of hyponatremia should include a combination of physical examination findings, basic laboratory studies, and invasive monitoring when available (class III). Obtaining levels of hormones such as antidiuretic hormone and natriuretic peptides is not supported by the literature (class III). Treatment of hyponatremia should be based on severity of symptoms (class III). The serum sodium level should not be corrected by more than 10 mmol/L/d (class III). Cerebral salt wasting should be treated with replacement of serum sodium and intravenous fluids (class III). Fludrocortisone may be considered in the treatment of hyponatremia in subarachnoid hemorrhage patients at risk of vasospasm (class I). Hydrocortisone may be used to prevent natriuresis in subarachnoid hemorrhage patients (class I). Hyponatremia in subarachnoid hemorrhage patients at risk of vasospasm should not be treated with fluid restriction (class II). Syndrome of inappropriate antidiuretic hormone may be treated with urea, diuretics, lithium, demeclocycline, and/or fluid restriction (class III).

CONCLUSION

The summarized literature on the evaluation and treatment of hyponatremia was used to develop practice management recommendations for hyponatremia in the neurosurgical population. However, the practice management recommendations relied heavily on expert opinion because of a paucity of class I evidence literature on hyponatremia.

Recurrent rhabdomyolysis associated with polydipsia-induced hyponatremia - a case report and review of the literature

Rhabdomyolysis involves the breakdown of muscle due to an inciting insult. It has been reported to have many etiologies. Some of the more common causes are trauma and medications. Therapy involves vigorous hydration with a crystalloid or bicarbonate infusion and aims to prevent renal failure caused by the release of myoglobin. This case report describes a patient with a recurrent episode of rhabdomyolysis associated with self-induced water intoxication. He was initially treated with a 3.0% saline infusion, followed by a sodium bicarbonate infusion, with correction of his electrolytes and resolution of the rhabdomyolysis.

Management of Hyponatremia and Clinical Use of Vasopressin Antagonists

Hyponatremia, the most common electrolyte disorder in hospitalized patients, has been associated with high rate of mortality among both this population and nonhospitalized patients. This review describes briefly the classification and pathogenesis of hyponatremia, and, in greater detail, the management of hyponatremia with a particular emphasis on the clinical pharmacology of arginine vasopressin (AVP) antagonists. This review includes more in-depth discussion on the pharmacology of conivaptan, an AVP antagonist recently approved by the United States Food and Drug Administration.

Disturbances of sodium in critically ill adult neurologic patients: a clinical review

Disorders of sodium and water balance are common in critically ill adult neurologic patients. Normal aspects of sodium and water regulation are reviewed. The etiology of possible causes of sodium disturbance is discussed in both the general inpatient and the neurologic populations. Areas of importance are highlighted with regard to the differential diagnosis of sodium disturbance in neurologic patients, and management strategies are discussed. Specific discussions of the etiology, diagnosis, and management of cerebral salt wasting syndrome, the syndrome of inappropriate antidiuretic hormone secretion, and central diabetes insipidus are presented, as well as the problems of overtreatment. The importance of diagnosis at an early stage of these diseases is stressed, with a recommendation for conservative management of milder cases.

[Severe hypernatremia: survival without neurologic sequelae]

Hypernatremia is an electrolyte disturbance most frequently caused by excess water loss and less frequently by increased sodium intake. The few reported cases of severe hypernatremia (> 190 mEq/l) had an adverse outcome with high mortality and/or severe neurologic sequelae. The first case was a 7-year-old girl with renal failure undergoing continuous venovenous hemodiafiltration therapy who presented hypernatremia (216 mEq/l) after incorrect preparation of dialysis fluid. The patient was treated with hemodiafiltration and hypernatremia was resolved in 48 hours. She had a convulsive crisis without subsequent neurologic impairment. The second patient, a 3-year-old girl with pseudohypoaldosteronism type I and encephalopathy, had hypernatremia (203 mEq/l) due to erroneous sodium administration, which was corrected in 36 hours with intravenous fluid therapy. Her neurologic status was unchanged by treatment. We conclude that children with extreme hypernatremia survive without neurologic sequelae if treatment achieves a progressive decrease of natremia.

Hyponatraemia in hip fracture patients

We performed a retrospective review of hyponatraemia in patients with hip fractures, before and after surgery. All patients admitted with fractures of the neck of femur who had a surgical intervention to deal with the fracture were included. Results were determined using two definitions for hyponatraemia. The incidence of pre-operative and post-operative hyponatraemia were both 2.8% if hyponatraemia was defined as [Na] < 130 mmol/l. No cases of hyponatraemia were found pre-operatively when hyponatraemia was defined as [Na] < 125 mmol/l. Using this definition the post operative incidence of hyponatraemia was 0.93%. The incidence of hyponatraemia in this group of patients is small. However the potentially severe affects of hyponatraemia warrant close monitoring of these patients and the establishment of methods to prevent this problem from occurring.

[Hypernatremia in neurosurgical pathology]

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.

Validation of a hand-held lactate device in determination of blood lactate in critically injured patients

OBJECTIVES

Admission blood lactate is an accurate predictor of injury severity and mortality in trauma patients. The purpose of this study was to evaluate a portable lactate analyzer in a clinical setting by patient care staff.

DESIGN

A prospective, single-operator control solution and patient sample study, using two test devices and a reference device.

SETTING

An urban Level I trauma center.

PATIENTS

A convenience sample of 47 trauma patients.

INTERVENTIONS

Intra-assay precision was demonstrated by performance of consecutive analyses of two lactate control solutions (high and low lactate control concentrations) by medical students and physicians. Split sample, simultaneous testing of the portable lactate analyzer was then performed on 66 whole blood specimens from a convenience sample of 47 trauma patients admitted to an urban Level 1 trauma center over 4 mos. Samples were tested simultaneously tested on two portable lactate analyzers and a reference instrument.

MEASUREMENTS AND MAIN RESULTS

Acceptable intra-assay precision was achieved. Regression analysis for two test instruments demonstrated a slope of 0.920, an intercept of 0.323, an r2 of .982, and an SEM of 0.496. Regression analysis for test instrument "A" vs. the reference instrument showed a slope of 0.861, an intercept of 0.209, an r2 of .977, and an SEM of 0.598. Regression analysis for test instrument "B" vs. the reference instrument demonstrated a slope of 0.929, an intercept of -0.095, an r2 of .983, and an SEM of 0.506.

CONCLUSIONS

Good correlation with a low SEM was obtained over a wide range of clinically relevant lactate values. Use of point of care lactate analysis will decrease analytic time, making an important diagnostic parameter immediately available in the critical care setting.

Rectus abdominis rhabdomyolysis after sit ups: unexpected detection by bone scan

Uptake of technetium-99m methylene diphosphonate by the rectus abdominis muscle was unexpectedly found in a 29 year old man who had started to perform 30 to 40 sit ups a day for five days before the bone scan. After a week of rest, serum creatine kinase activity was still abnormal but muscle uptake of technetium-99m methylene diphosphonate had ceased. This specific muscle injury after short term sit ups as well as the resolution of the phenomenon within a week are of interest.

Iatrogenic acute hyponatraemia in a college athlete

Hyponatraemia is one of the most common electrolyte abnormalities, leading to significant morbidity and mortality. In the most basic sense, hyponatraemia can be due to sodium loss or fluid excess. The extracellular fluid status is used to clinically divide hyponatraemia into three categories to help to determine both the cause and treatment required. Hyponatraemic patients can be categorised on the basis of their fluid status as hypovolaemic, euvolaemic, or hypervolaemic. Another distinction to make in evaluating hyponatraemia is whether the onset was acute or chronic in nature. The case presented here is iatrogenic acute hypervolaemic hyponatraemia in a college athlete. The patient presented in respiratory distress with an altered mental status after the administration of hypotonic fluids for treatment of muscle cramps. Treatment included intubation, water restriction, and furosemide, to which he responded favourably. Hyponatraemia should be in the differential diagnosis for patients presenting after intravenous fluid administration.

Functional significance of cell volume regulatory mechanisms

To survive, cells have to avoid excessive alterations of cell volume that jeopardize structural integrity and constancy of intracellular milieu. The function of cellular proteins seems specifically sensitive to dilution and concentration, determining the extent of macromolecular crowding. Even at constant extracellular osmolarity, volume constancy of any mammalian cell is permanently challenged by transport of osmotically active substances across the cell membrane and formation or disappearance of cellular osmolarity by metabolism. Thus cell volume constancy requires the continued operation of cell volume regulatory mechanisms, including ion transport across the cell membrane as well as accumulation or disposal of organic osmolytes and metabolites. The various cell volume regulatory mechanisms are triggered by a multitude of intracellular signaling events including alterations of cell membrane potential and of intracellular ion composition, various second messenger cascades, phosphorylation of diverse target proteins, and altered gene expression. Hormones and mediators have been shown to exploit the volume regulatory machinery to exert their effects. Thus cell volume may be considered a second message in the transmission of hormonal signals. Accordingly, alterations of cell volume and volume regulatory mechanisms participate in a wide variety of cellular functions including epithelial transport, metabolism, excitation, hormone release, migration, cell proliferation, and cell death.

Thiazide-induced hyponatremia in the postoperative total joint replacement patient

The thiazide diuretic is a common medication in the elderly population for the treatment of hypertension. These same patients are the largest population for surgical intervention for joint arthroplasty. Postoperative management of these patients has shown to be complicated by hyponatremia associated with the use of thiazide diuretics. This study evaluates a consecutive series of 408 patients undergoing elective joint arthroplasty. An association was found with the use of thiazide diuretics in the preoperative period and the development of postoperative hyponatremia. The study is presented, along with a relevant review of the literature and suggestions for the orthopedic staff to limit the risk of hypoantremia and prolonged hospitalization in an otherwise stable postoperative course.

Effects of small-peptide and whole-protein enteral feedings on serum proteins and diarrhea in critically ill patients: a randomized trial

BACKGROUND

It has been proposed that enteral feeding formulas containing small peptides are more efficacious and better tolerated than whole-protein formulas in critically ill patients.

METHODS

Intensive care unit patients were stratified with regard to treatment with antibiotics and serum albumin and randomized to treatment with a small-peptide enteral diet or an isoenergetic, isonitrogenous whole-protein diet for 10 days. To assess efficacy, we measured serum prealbumin and fibronectin, and to assess tolerance, we monitored the incidence of diarrhea. A protocol was followed to ascertain all causes of diarrhea (defined as > 200 g stool or > or = 3 liquid stools on 2 consecutive days).

RESULTS

Fifty subjects completed the trial. Serum prealbumin and fibronectin increased between 21% and 36% in both groups, but the increase was significant only in the small-peptide group. The change in fibronectin between days 5 and 10 was significantly greater in the small-peptide group (p = .02). Diarrhea occurred in 10 subjects (17.8% of days) receiving small-peptide feeding and 4 subjects (7.5% of days) receiving whole-protein feeding (P = .07 for incidence and 0.03 for prevalence), but the difference was explained by the coincidental use of more diarrhea-causing medications in the former. Only one case of diarrhea could be attributed to tube feeding.

CONCLUSIONS

During 10 days of feeding, the small-peptide diet produced slightly greater increases in serum rapid-synthesis proteins than did the whole-protein diet, especially between days 5 and 10. The clinical implications of this difference between the diets are unknown. Both small-peptide and whole-protein diets were well tolerated.

[Indications and role of albumin, plasma volume expansion excluded, in the preoperative or postoperative management of portal hypertension]

Low serum albumin levels are common in patients with cirrhosis and liver failure. Decreased synthesis is the main but not the only mechanism leading to decreased serum levels. The consequences of low albumin concentrations are a decreased plasma colloid osmotic pressure and a decreased binding of liposoluble xenobiotics and endogenous substances. Besides the fluid accumulation in pleura and peritoneum, the complications directly related to low serum albumin levels have been only poorly assessed. An increase in serum albumin levels (by a few g.L-1) for a few days can be achieved by the infusion of large amounts of human albumin (approximately 120 g over 3 days). The efficacy of this treatment has been only tested in association with large paracentesis: albumin infusion, which induces volume expansion, reduced the incidence of hyponatremia and functional renal failure. No significant effect on ascites production rate or survival has been observed. Similar results were achieved through polygelin or dextran-70 infusions. No well-conducted controlled study on the value of albumin infusion in other circumstances apart from cirrhotic patients is available. In conclusion, albumin infusion should be reserved to the treatment of hyponatraemia or functional renal failure complicating cirrhosis with severe liver failure and marked hypoalbuminaemia, when the infusion of colloids failed to correct these anomalies.

Hyponatremia, convulsions and neuroleptic malignant syndrome in a male with schizoaffective disorder

OBJECTIVE

The aim of the study was to highlight the diagnostic difficulties occurring when hyponatremia presents concurrently with neuroleptic malignant syndrome (NMS). Diagnostic issues in the differentiation between hyponatremia and NMS are discussed.

CLINICAL PICTURE

A case of dilutional hyponatremia (DH) secondary to psychogenic polydipsia (PP) associated with NMS occurring in a male with schizoaffective disorder is described. The clinical picture was complicated by convulsions, perhaps due to clonazepam withdrawal and possible lithium toxicity.

TREATMENT

The patient was treated with supportive medical measures.

OUTCOME

The patient made a full recovery.

CONCLUSIONS

Hyponatremia and NMS have been found to be associated. This association may be due to an undefined common pathogenesis, or may be coincidental. Hyponatremia may also hinder the diagnosis of NMS.

Acute adrenal insufficiency in the burn intensive care unit

Acute adrenal insufficiency may underlie a confusing, stormy, intensive care unit course after a burn. The aetiology is most likely to be adrenal haemorrhage despite the absence of a coagulopathy. This report describes two patients who were diagnosed antemortem and successfully treated with replacement therapy. The aetiology, presentation, diagnosis and treatment of acute adrenal insufficiency in the intensive care unit is reviewed.