Cerebral salt wasting syndrome in children with acute central nervous system injury

Pituitary Apoplexy-associated Cerebral Salt Wasting Syndrome: A Case Report and Literature Review

PURPOSE

This is a case report of a patient experiencing hyponatremia who was ultimately diagnosed with pituitary apoplexy-associated cerebral salt wasting syndrome (CSWS).

METHODS

Laboratory tests, clinical evaluations, and magnetic resonance imaging were performed by specialists.

FINDINGS

The patient presented with severe headache, thirst, and polyuria. Results of laboratory tests indicated hyponatremia, decreased plasma osmolality, and elevated urine osmolality. Fluid restriction worsened the situation, and normal saline treatment helped return serum sodium and chloride levels to normal. Pituitary apoplexy-associated CSWS was finally considered.

IMPLICATIONS

Pituitary apoplexy is a rare but reasonable etiology for CSWS with hyponatremia. Saline therapy is usually effective.

Pediatric Perioperative Clinical Pharmacy Practice: Clinical Considerations and Management: An Opinion of the Pediatrics and Perioperative Care Practice and Research Networks of the American College of Clinical Pharmacy

Pediatric perioperative clinical pharmacists are uniquely positioned to provide therapeutic and medication management expertise at a particularly vulnerable transition of care from the preoperative space, through surgery, and postoperative setting. There are many direct-patient care activities that are included in the role of the pediatric perioperative pharmacist, as well as many opportunities to develop effective, optimized, and safe medication use processes. This article outlines many of the areas in which a pediatric perioperative clinical pharmacist may intervene.

Concurrent central diabetes insipidus and cerebral salt wasting disease in a post-operative case of craniopharyngioma: a case report

BACKGROUND

Water and electrolyte disorders commonly encountered in children post-surgery involving hypothalamus and posterior pituitary, are central diabetes insipidus, syndrome of inappropriate secretion of anti-diuretic hormone and cerebral salt wasting disease. Delayed diagnosis and inadequate management of such cases may lead to worsened neurological outcomes with a high mortality rate.

CASE PRESENTATION

Here we report the case of a 7-year-old girl who underwent surgical resection of a craniopharyngioma, following which she initially developed central diabetes insipidus. However, later on in the course of her illness she developed symptomatic hyponatremia with natriuresis which was diagnosed to be due to cerebral salt wasting disease. This combination of central diabetes insipidus and cerebral salt wasting syndrome is a rare occurrence and poses a diagnostic challenge. Diagnosis and management can be even more difficult when these conditions precede or coexist with each other.

CONCLUSION

In such cases development of hyponatremia should always prompt consideration of unusual causes like cerebral salt wasting disease in addition to the classically described syndrome of inappropriate secretion of anti-diuretic hormone. Hence, a thorough knowledge of these disorders along with intensive monitoring of fluid and sodium status is critical for timely diagnosis and management of these patients.

Incidence and Possible Predictors of Sodium Disturbance After Craniopharyngioma Resection Based on QST Classification

OBJECTIVE

Serum sodium abnormalities are one of the most common manifestations after radical craniopharyngioma (CP) excision. The aim of this study was to report the incidence and possible predictors of serum sodium disturbance and explore features of sodium destabilization manifestation among QST classification results after CP resection.

METHODS

A retrospective analysis was performed of clinical, biochemical, radiologic, and operative data for 134 successive patients who underwent primary CP removal between September 2016 and March 2018. Univariate and multivariate analyses were conducted to determine predictors.

RESULTS

Sixty patients (44.8%) experienced hyponatremia and 67 patients (50%) hypernatremia; the median time of onset was 6 days and the first day after surgery, respectively. The incidence, onset, severity, and type of sodium disturbance among different types of CP differed significantly based on statistical tests (P < 0.05). Sodium disturbance was more common and severe in patients with type T tumors (P < 0.05). Age, tumor type, and preoperative diabetes insipidus were independent prognostic factors for obvious disorders of serum sodium.

CONCLUSIONS

Hyponatremia/hypernatremia is common after primary CP resection. The site of tumor origin has a direct effect on the growth pattern of CP, which may serve as a useful index for anticipating sodium perturbation after surgery. The level of sodium in children and patients with type T tumors, preoperative diabetes insipidus should be monitored closely throughout hospitalization.

Cerebral salt-wasting syndrome in a patient with status epilepticus: a rare association

Hyponatraemia is one of the most common and serious electrolyte abnormalities in patients with neurological diseases. Assessing the intravascular fluid status, urine sodium, urine and serum osmolality helps to narrow down the differential diagnosis. Differentiation between cerebral salt-wasting syndrome (CSWS), diabetes insipidus and syndrome of inappropriate antidiuretic hormone (SIADH) secretion is absolutely necessary for correct management of hyponatraemia in this group of patients. In this case report, we have presented a 46-year-old gentleman who was admitted to intensive care unit (ICU) with status epilepticus and developed hyponatraemia during course of his ICU stay, diagnosed as CSWS and managed with normal saline and fludrocortisone. His serum sodium gradually improved, consciousness was regained and later shifted to general ward on antiepileptic treatment.

Cerebral Salt-wasting Syndrome in a Critically Ill Patient: An Easily Neglected Syndrome in Intensive Care Unit (ICU)

BACKGROUND

Cerebral salt-wasting syndrome (CSWS), which usually secondary to cerebral diseases, is characterized by hyponatremia and hypovolemia. In clinical practice, it is quite difficult to distinguish CSWS from other hyponatremia syndrome, especially in Intensive Care Unit (ICU) where the conditions of patients are more complicated. Nonetheless, it is crucial because treatments might be fundamentally different.

CASE PRESENTATION

We discuss a case of patient who presented with refractory hyponatremia and hypovolemia after traumatic brain injury, finally was diagnosed with CSWS, and successfully treated with corticotropin.

CONCLUSIONS

This case report provides a unique opportunity to observe the trigger of subdural effusion-induced CSWS, and also it provides the classical therapy for CSWS in a critically ill patient. In view of the difficulty to tell CSWS from other similar diseases in ICU, ICU doctors should be aware of such condition.

Clinical Approach to Sodium Homeostasis Disorders in Children with Pituitary-Suprasellar Tumors

Children with pituitary-suprasellar tumors are at high risk of developing sodium metabolism disorders since the tumoral mass itself or surgical and medical treatment can damage AVP release circuits. Additional risk factors are represented by the use of hypotonic fluids, the young age, total parenteral nutrition, and obstructive hydrocephalus secondary to tumor pathology. The most frequent hyponatremic disorders related to AVP in these patients are the syndrome of inappropriate ADH secretion and the cerebral/renal salt wasting syndrome, while hypernatremic conditions include central diabetes insipidus (CDI) and adipsic CDI. The main challenge in the management of these patients is to promptly distinguish the AVP release disorder at the base of the sodium imbalance and treat it correctly by avoiding rapid sodium fluctuations. These disorders can coexist or follow each other in a few hours or days; therefore, careful clinical and biochemical monitoring is necessary, especially during surgery, the use of chemotherapeutic agents, or radiotherapy. This monitoring should be performed by experienced healthcare professionals and should be multidisciplinary, including pediatric endocrinologists, neurosurgeons, and oncologists since maintaining sodium homeostasis also plays a prognostic role in terms of disease survival, therapeutic response, hospitalization rate, and mortality. In this review, we analyze the management of sodium homeostasis disorders in children with pituitary-suprasellar tumors and discuss the main challenges in the diagnosis and treatment of these conditions based on literature data and over 30 years of clinical experience at our Department of Pediatric Endocrinology.

Think central nervous system tuberculosis, also in low-risk children: a Danish nationwide survey

BACKGROUND

Paediatric central nervous system (CNS) tuberculosis (TB) imposes a high risk of death and neurologic sequelae, particularly if the diagnosis is delayed. Children from non-TB endemic countries are particularly at risk of delayed or missed diagnosis. We aimed to investigate CNS TB in Denmark, a TB low-endemic country and where Bacillus Calmette-Guerin (BCG) vaccination is not a part of the vaccination schedule.

METHODS

A nationwide retrospective case survey of all children with CNS TB in 2000-2015 identified through the National Danish TB Notification Register. We assessed epidemiology, clinical and paraclinical features, diagnostic criteria, treatment and outcome.

RESULTS

Nine ethnic Danes and 12 children from TB-endemic countries with CNS TB were identified. Clinical features, C-reactive protein, chest X-ray and indirect TB screening assays all had low sensitivity (19-75%). All (18/18) patients had elevated cerebrospinal fluid (CSF) white blood cells and 15 of 17 (88%) had a combination of at least two characteristic CSF findings (lymphocyte predominance, elevated protein and/or hypoglycorrhachia). Cerebral computed tomography and magnetic resonance imaging were abnormal in 10 of 16 (63%) and 12 of 14 (86%), respectively. Treatment was initiated after a median of 3 days in children from TB-endemic countries, and after 10 days in ethnic Danish children. One patient died (5%): A native Danish girl who died before the diagnosis was established.

CONCLUSIONS

Children from non-TB endemic countries may be at risk of delayed diagnosis and poorer prognosis compared to high-risk children. Cerebral magnetic resonance imaging and characteristic CSF findings had high diagnostic sensitivity.

Syndrome of Inappropriate Antidiuresis

The syndrome of inappropriate antidiuresis (SIAD) is a common cause of hyponatremia in hospitalized children. SIAD refers to euvolemic hyponatremia due to nonphysiologic stimuli for arginine vasopressin production in the absence of renal or endocrine dysfunction. SIAD can be broadly classified as a result of tumors, pulmonary or central nervous system disorders, medications, or other causes such as infection, inflammation, and the postoperative state. The presence of hypouricemia with an elevated fractional excretion of urate can aid in the diagnosis. Treatment options include fluid restriction, intravenous saline solutions, oral sodium supplements, loop diuretics, oral urea, and vasopressin receptor antagonists (vaptans).

Successful Use of Fludrocortisone in a Child with Refractory Cerebral Salt Wasting Syndrome: A Case Report and Review of Literature

Hyponatremia post-neurosurgical intervention can be dangerous and potentially life-threatening. Two of its most common causes are cerebral salt wasting (CSW) and syndrome of inappropriate anti-diuretic hormone release (SIADH). CSW is proposed to be secondary not only to the elevated levels of circulating atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) but inhibition of steroidogenesis in the zona glomerulosa of the adrenal cortex, thus resulting in mineralocorticoid deficiency. We present a two-year-old male who had developed acute hyponatremia secondary to CSW on post-operative day two after a sub-total resection of a low-grade juvenile pilocytic astrocytoma (WHO grade I). Fludrocortisone was successfully used to manage the refractory hyponatremia and alleviated the need to use very large amounts of oral sodium supplementation.

Mycoplasma pneumoniae- associated encephalitis complicated by cerebral salt wasting syndrome

Cerebral salt wasting syndrome can occur in children with encephalitis. Clinicians should be aware of hyponatremia in patients who develop polyuria with the signs of dehydration and deteriorated consciousness. Furthermore, patients who present with status epilepticus or who are suspected to have high intracranial pressure may have an increased risk of cerebral salt wasting syndrome.

Exophytic bulbar pilocytic astrocytoma and post-operative cerebral salt wasting syndrome

Cerebral salt wasting syndrome (CSWS) is a well-described consequence of several neurological disorders. Although the exact etiology of CSWS is still not completely elucidated, it is believed that the hypothalamus plays a pivotal role in the genesis of this disorder. We report for the first time 3 cases of CSWS occurring during the post-operative course following surgical resection of exophytic bulbar pilocytic astrocytomas in children. Since these 3 cases shared in common a medial implication of the medulla, we suggest that specific interconnectivity between the dorso-medial portion of the medulla oblongata and the hypothalamus might thus represent an anatomical pathway of interest in the pathogenesis of CSWS. Our findings suggest that the resection of medially located exophytic bulbar tumors might constitutes a risk factor in the development of CSWS. Particular care should thus be carried towards the prompt detection and treatment of CSWS in the post-operative courses of exophytic bulbar tumors.

Cerebral Salt-Wasting Syndrome Caused by Minor Head Injury

A 34-year-old woman was admitted to hospital after sustaining a head injury in a motor vehicle accident (day 1). No signs of neurological deficit, skull fracture, brain contusion, or intracranial bleeding were evident. She was discharged without symptoms on day 4. However, headache and nausea worsened on day 8, at which time serum sodium level was noted to be 121 mEq/L. Treatment with sodium chloride was initiated, but serum sodium decreased to 116 mEq/L on day 9. Body weight decreased in proportion to the decrease in serum sodium. Cerebral salt-wasting syndrome was diagnosed. This case represents the first illustration of severe hyponatremia related to cerebral salt-wasting syndrome caused by a minor head injury.

Transient Oliguria during Anesthesia in Cerebral Salt Wasting Syndrome

Cerebral salt wasting syndrome is a hyponatremic and hypovolemic condition caused by intracranial disorders, such as head injury, subarachnoid hemorrhage, brain tumor, and brain operations. We report a case of a 5-year-old girl that had cerebral salt wasting syndrome with marked polyuria who showed transient oliguria during general anesthesia. The patient had undergone an operation for traumatic intracranial hemorrhage three months prior and has had marked polyuria and hyponatremia since then. After induction of anesthesia for cranioplasty, the patient had oliguria during surgery and then resumed polyuria in the post-operative period.

Cerebral salt-wasting syndrome in a child with Wernicke encephalopathy treated with fludrocortisone therapy: A case report

RATIONALE FOR THIS CASE REPORT

Cerebral Salt-Wasting Syndrome (CSWS) is characterized by hyponatremia and sodium wasting in the urine. These conditions are triggered by various neurosurgical disorders such as subarachnoid hemorrhage, brain tumor, head injury, and brain surgery. To our knowledge, CSWS caused by Wernicke encephalopathy (WE) has been rarely reported.

PRESENTING CONCERNS OF THE PATIENT

A 2-year-old male patient presented to our hospital due to a seizure attack. He had been neglected and refused to take food for a long time (body weight < 3rd percentile). During admission, the patient showed low serum osmolality, high urine osmolality, dehydration state, increased urine output, and negative water balance, a diagnosis of CSWS was made.

DIAGNOSES, INTERVENTIONS, AND OUTCOMES

Brain MRI displayed symmetrical lesions of T2WI and FLAIR high signal intensity in the peri-aqueductal and hypothalamic areas, which suggests Wernicke encephalopathy. For the early diagnosis of WE, neuroimaging studies can be an important marker. Thiamine hydrochloride was administered at a dose of 100 mg/day for 3 weeks. Cerebral salt-wasting syndrome was subsequently diagnosed due to persistent hyponatremia, dehydrated state, and high urine sodium with massive urination.

MAIN LESSONS LEARNED FROM THIS CASE

Wernicke encephalopathy is a very rare cause of cerebral salt-wasting syndrome in pediatrics patients. The patient had a good outcome after hypertonic solution and fludrocortisone therapy.

A study of hyponatremia in tuberculous meningitis

SETTING

In view of paucity of studies on predictors of hyponatremia in tuberculous meningitis (TBM) and its influence on outcome, this study was undertaken.

OBJECTIVE

To study the frequency, predictors and prognosis of hyponatremia in TBM.

DESIGN

In this prospective hospital based study, 76 patients with TBM (definite 18 and probable 58) were enrolled. The severity of meningitis was graded as I-III and hyponatremia as severe (<120mEq/L), moderate (120-129mEq/L) or mild (130-134mEq/L). Hospital death was noted and functional outcome was assessed by modified Rankin Scale (mRS) on discharge.

RESULTS

34 (44.7%) TBM patients had hyponatremia (mild 3, moderate 23 and severe 8). Hyponatremia was due to cerebral salt wasting in 17, syndrome of inappropriate secretion of antidiuretic hormone in 3 and miscellaneous causes in 14 patients. Hyponatremia was related to GCS score and basal exudates. Outcome of TBM was related to duration of hospitalization, GCS score, focal deficit, mechanical ventilation, severity of TBM, age and comorbidities. Cerebral salt wasting was related to severity of TBM.

CONCLUSION

Hyponatremia occurred in 44.7% of TBM patients. Cerebral salt wasting was the commonest cause of hyponatremia and was related to the severity of TBM.

Management of electrolyte and fluid disorders after brain surgery for pituitary/suprasellar tumours

Disturbances in salt and water balances are relatively common in children after brain surgeries for suprasellar and pituitary tumours, presenting diagnostic and therapeutic challenges. Although hypernatraemia associated with central diabetes insipidus is commonly encountered, it is hyponatraemia (HN) that poses more of a diagnostic dilemma. The main differential diagnoses causing HN are the syndrome of inappropriate antidiuretic hormone secretion, marked by inappropriate retention of water, and cerebral salt wasting, characterized by polyuria and natriuresis. Diagnosis and management can be even more difficult when these conditions precede or coexist with each other. These diagnostic and therapeutic dilemmas are discussed in detail in this review.

Etiology of postoperative hyponatremia following pediatric intracranial tumor surgery

OBJECT Cerebral salt wasting (CSW) and the syndrome of inappropriate antidiuretic hormone secretion (SIADH) cause postoperative hyponatremia in neurosurgery patients, can be difficult to distinguish clinically, and are associated with increased morbidity. The authors aimed to determine risk factors associated with CSW and SIADH among children undergoing surgery for intracranial tumors. METHODS This retrospective cohort study included children 0-19 years of age who underwent a first intracranial tumor surgery with postoperative hyponatremia (sodium ≤ 130 mEq/L). CSW was differentiated from SIADH by urine output and fluid balance, exclusive of other causes of hyponatremia. The CSW and SIADH groups were compared with basic bivariate analysis and recursive partitioning. RESULTS Of 39 hyponatremic patients, 17 (44%) had CSW and 10 (26%) had SIADH. Patients with CSW had significantly greater natriuresis compared with those with SIADH (median urine sodium 211 vs 28 mEq/L, p = 0.01). Age ≤ 7 years and female sex were significant risk factors for CSW (p = 0.03 and 0.04, respectively). Both patient groups had hyponatremia onset within the first postoperative week. Children with CSW had trends toward increased sodium variability and symptomatic hyponatremia compared with those with SIADH. Most received treatment, but inappropriate treatment was noted to worsen hyponatremia. CONCLUSIONS The authors found that CSW was more common following intracranial tumor surgery and was associated with younger age and female sex. Careful assessment of fluid balance and urine output can separate patients with CSW from those who have SIADH, and high urine sodium concentrations (> 100 mEq/L) support a CSW diagnosis. Patients with CSW and SIADH had similar clinical courses, but responded to different interventions, making appropriate diagnosis and treatment imperative to prevent morbidity.

Diagnosis and Management of Combined Central Diabetes Insipidus and Cerebral Salt Wasting Syndrome After Traumatic Brain Injury

BACKGROUND

Combined central diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury (TBI) is rare, is characterized by massive polyuria leading to severe water and electrolyte disturbances, and usually is associated with very high mortality mainly as a result of delayed diagnosis and improper management.

METHODS

We retrospectively reviewed the clinical presentation, management, and outcomes of 11 patients who developed combined central diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury to define distinctive features for timely diagnosis and proper management.

RESULTS

The most typical clinical presentation was massive polyuria (10,000 mL/24 hours or >1000 mL/hour) refractory to vasopressin alone but responsive to vasopressin plus cortisone acetate. Other characteristic presentations included low central venous pressure, high brain natriuretic peptide precursor level without cardiac dysfunction, high 24-hour urine sodium excretion and hypovolemia, and much higher urine than serum osmolarity; normal serum sodium level and urine specific gravity can also be present. Timely and adequate infusion of sodium chloride was key in treatment. Of 11 patients, 5 had a good prognosis 3 months later (Extended Glasgow Outcome Scale score ≥6), 1 had an Extended Glasgow Outcome Scale score of 4, 2 died in the hospital of brain hernia, and 3 developed a vegetative state.

CONCLUSIONS

For combined diabetes insipidus and cerebral salt wasting syndrome after traumatic brain injury, massive polyuria is a major typical presentation, and intensive monitoring of fluid and sodium status is key for timely diagnosis. To achieve a favorable outcome, proper sodium chloride supplementation and cortisone acetate and vasopressin coadministration are key.

Syndrome of inappropriate antidiuretic hormone secretion and cerebral/renal salt wasting syndrome: similarities and differences

Hyponatremia (sodium levels of <135 mEq/L) is one of the most common electrolyte imbalances in clinical practice, especially in patients with neurologic diseases. Hyponatremia can cause cerebral edema and brain herniation; therefore, prompt diagnosis and proper treatment is important in preventing morbidity and mortality. Among various causes of hyponatremia, diagnosing syndrome of inappropriate antidiuretic hormone secretion (SIADH) and cerebral/renal salt wasting syndrome (C/RSW) is difficult due to many similarities. SIADH is caused by excess of renal water reabsorption through inappropriate antidiuretic hormone secretion, and fluid restriction is the treatment of choice. On the other hand, C/RSW is caused by natriuresis, which is followed by volume depletion and negative sodium balance and replacement of water and sodium is the mainstay of treatment. Determinating volume status in hyponatremic patients is the key point in differential between SIADH and C/RSW. However, in most situations, differential diagnosis of these two diseases is difficult because they overlap in many clinical and laboratory aspects, especially to assess differences in volume status of these patients. Although distinction between the SIADH and C/RSW is difficult, improvement of hypouricemia and an increased fractional excretion of uric acid after the correction of hyponatremia in SIADH, not in C/RSW, may be one of the helpful points in discriminating the two diseases. In this review, we compare these two diseases regarding the pathophysiologic mechanisms, diagnosis, and therapeutic point of view.

Cerebral salt wasting in status epilepticus: two cases and review of the literature

BACKGROUND

Cerebral salt wasting is a hypovolemic hyponatremia state, caused by natriuresis and diuresis. The most important element of treatment is to replace the volume and sodium loss and improve the current clinic.

PATIENTS

We present two children who were treated in the intensive care unit who subsequently developed cerebral salt wasting. Diagnosis was based on hyponatremia associated with high urinary sodium excretion and inappropriately high urine output in the presence of dehydration. As part of the treatment, one patient was given fluid and sodium replacement, measures that were insufficient in the other patient, who also required fludrocortisone treatment.

CONCLUSION

The status epilepticus may be involved in the etiology of cerebral salt wasting. In both patients, cerebral salt wasting was detected in the posttreatment follow-up evaluations. Cerebral salt wasting is particularly likely to occur in individuals with status epilepticus, and the electrolyte and hydration status of these patients should be monitored closely, even after the convulsions are taken under control.

The incidence of postoperative hyponatremia and associated neurological sequelae in children with intracranial neoplasms

OBJECT

Intracranial tumors are common pediatric neoplasms and account for substantial morbidity among children with cancer. Hyponatremia is a known complication of neurosurgical procedures and is associated with higher morbidity among neurosurgical patients. The authors aimed to estimate the incidence of hyponatremia, identify clinical characteristics associated with hyponatremia, and assess the association between hyponatremia and patient outcome among children undergoing surgery for intracranial tumors.

METHODS

This is a retrospective cohort study of children ranging in age from 0 to 19 years who underwent an initial neurosurgical procedure for an intracranial tumor between January 2001 and February 2012. Hyponatremia was defined as serum sodium ≤ 130 mEq/L during admission.

RESULTS

Hyponatremia during admission occurred in 39 (12%) of 319 patients and was associated with young age and obstructive hydrocephalus (relative risk [RR] 2.9 [95% CI 1.3-6.3]). Hyponatremic patients were frequently symptomatic; 21% had seizures and 41% had altered mental status. Hyponatremia was associated with complicated care including mechanical ventilation (RR 4.4 [95% CI 2.5-7.9]), physical therapy (RR 4 [95% CI 1.8-8.8]), supplemental nutrition (RR 5.7 [95% CI 3.3-9.8]), and infection (RR 5.7 [95% CI 3.3-9.5]). Hyponatremic patients had a 5-fold increased risk of moderate or severe disability on the basis of their Pediatric Cerebral Performance Category score at discharge (RR 5.3 [95% CI 2.9-9.8]). Obstructive hydrocephalus (adjusted odds ratio [aOR] 3.24 [95% CI 1.38-8.94]) and young age (aOR 0.92 [95% CI 0.85-0.99]) were independently associated with hyponatremia during admission. Hyponatremia was independently associated with moderate or worse disability by Pediatric Cerebral Performance Category score at discharge (aOR 6.2 [95% CI 3.0-13.03]).

CONCLUSIONS

Hyponatremia was common, particularly among younger children and those with hydrocephalus. Hyponatremia was frequently symptomatic and was associated with more complicated hospital courses. Hyponatremia was independently associated with worse neurological outcome when adjusted for age and tumor factors. This study serves as an exploratory analysis identifying important risk factors for hyponatremia and associated sequelae. Further research into the causes of hyponatremia and the association with poor outcome is needed to determine if prevention and treatment of hyponatremia can improve outcomes in these children.

Cerebral salt wasting syndrome in post-operative pediatric brain tumor patients

BACKGROUND

Cerebral salt wasting syndrome (CSWS) and the syndrome of inappropriate antidiuretic hormone (SIADH) are both causes of hyponatremia in pediatric neurosurgical patients often with similar presenting symptoms; however, despite similar clinical characteristics the treatment for CSWS and SIADH can be drastically different, which makes the distinction critical for post-operative treatment. Further complicating matters, are the exact mechanism for CSWS which remains unclear, and the incidence and severity of CSWS is not well studied in pediatric neurosurgical patients. We hypothesized that CSWS occurs frequently in post-operative brain tumor patients and is an important cause of post-operative hyponatremia in these patients.

METHODS

We designed a single institution retrospective cohort study of all pediatric brain tumor patients undergoing craniotomy for tumor resection at our institution between January 2005 and December 2009.

RESULTS

Of the 282 patients undergoing 291 operations, post-operative CSWS was identified in 15 cases (5%), and was more frequently observed than SIADH (nine cases, 3%). Median onset of CSWS was on post-operative day 3, lasting a median of 2.5 days. Patients with CSWS were more likely to have suffered post-operative stroke (40 vs. 4.6%, P < 0.001), have chiasmatic/hypothalamic tumors (40 vs. 3.8%, P = 0.002), and be younger (mean age 5.9 vs. 9.7 years, P = 0.01) than eunatremic patients. In addition, nearly half of the patients with CSWS (47%) had post-operative hyponatremic seizures.

CONCLUSION

The diagnosis of CSWS should be strongly considered in hyponatremic pediatric patients with significant natriuresis following brain tumor resection, and a treatment initiated promptly to prevent neurologic sequeleae.

Common endocrine issues in the pediatric intensive care unit

Thyroid hormone is central to normal development and metabolism. Abnormalities in thyroid function in North America often arise from autoimmune diseases, but they rarely present as critical illness. Severe deficiency or excess of thyroid hormone both represent life-threatening disease, which must be treated expeditiously and thoroughly. Such deficiencies must be considered, because presentation may be nonspecific.

Syndrome of inappropriate antidiuresis and cerebral salt wasting syndrome: are they different and does it matter?

The syndrome of inappropriate antidiudresis (SIAD) and cerebral salt wasting (CSW) are similar conditions with the main difference being the absence or presence of volume depletion. The two conditions may be indistinguishable at presentation, as volume status is difficult to assess, which can lead to under-diagnosis of CSW in patients with central nervous system (CNS) disease. Carefully conducted studies in patients with CNS disease have indicated that CSW may be more common than SIAD. CSW may be differentiated from SIAD based on the persistence of hypouricemia and increased fractional excretion of urate following the correction of hyponatremia. Hyponatremia should be prevented if possible and treated promptly when discovered in patients with CNS disease as even mild hyponatremia could lead to neurological deterioration. Fluid restriction should not be used for the prevention or treatment of hyponatremia in hospitalized patients with CNS disease as it could lead to volume depletion especially if CSW is present. 0.9% sodium chloride may not be sufficiently hypertonic for the prevention of hyponatremia in hospitalized patients with CNS disease and a more hypertonic fluid may be required. The preferred therapy for the treatment of hyponatremia in patients with CNS disease is 3% sodium chloride.

Hyponatremia with intracranial malignant tumor resection in children

OBJECT

Intracranial neoplasms are the second most common childhood cancer, and lead to significant morbidity and mortality. Hyponatremia is a complication associated with neurosurgical procedures, but children undergoing intracranial tumor resection have not been selectively studied. In this study, the authors aimed to determine the incidence and risk factors associated with hyponatremia among children undergoing intracranial neoplasm resection.

METHODS

A retrospective cohort was compiled using the 2006 Kids' Inpatient Database to identify children younger than 21 years of age who underwent intracranial neoplasm resection. Hyponatremia was ascertained by diagnosis codes. Bivariate analyses were conducted using chi-square and Mann-Whitney U-tests. Logistic regression models were developed to evaluate factors associated with hyponatremia in bivariate analyses.

RESULTS

Hyponatremia occurred in 205 (8.7%) of 2343 annual weighted cases, and was independently associated with tumor location in the deep brain structures and ventricles compared with the cortical area (adjusted odds ratio [aOR] 2.4; 95% CI 1.1-5.3). Hyponatremia was also associated with obstructive hydrocephalus (aOR 2.7; 95% CI 1.7-4.3) and emergency department admission (aOR 1.7; 95% CI 1.1-2.4). Hyponatremia was significantly associated with mechanical ventilation, ventriculostomy placement, ventriculoperitoneal shunt placement, and sepsis. Hyponatremia was also associated with a significantly longer average length of stay (24.6 vs 10.2 days), higher average charges ($191,000 vs $92,000), and a higher percentage of discharges to intermediate-care facilities.

CONCLUSIONS

Hyponatremia commonly occurs with resection of intracranial malignant tumors, especially for lesions located in the deep brain and in patients with obstructive hydrocephalus. Hyponatremia was associated with higher morbidity. Further research is needed to develop targeted monitoring and intervention strategies to decrease perioperative hyponatremia and to determine if this could decrease the number of complications in this specialized population.

Renal salt-wasting syndrome in children with intracranial disorders

Hypotonic hyponatremia, a serious and recognized complication of any intracranial disorder, results from extra-cellular fluid volume depletion, inappropriate anti-diuresis or renal salt-wasting. The putative mechanisms by which intracranial disorders might lead to renal salt-wasting are either a disrupted neural input to the kidney or the elaboration of a circulating natriuretic factor. The key to diagnosis of renal salt-wasting lies in the assessment of extra-cellular volume status: the central venous pressure is currently considered the yardstick for measuring fluid volume status in subjects with intracranial disorders and hyponatremia. Approximately 110 cases have been reported so far in subjects ≤18 years of age (male: 63%; female: 37%): intracranial surgery, meningo-encephalitis (most frequently tuberculous) or head injury were the most common underlying disorders. Volume and sodium repletion are the goals of treatment, and this can be performed using some combination of isotonic saline, hypertonic saline, and mineralocorticoids (fludrocortisone). It is worthy of a mention, however, that some authorities contend that cerebral salt wasting syndrome does not exist, since this diagnosis requires evidence of a reduced arterial blood volume, a concept but not a measurable variable.

Central diabetes insipidus in children with acute brain insult

Central diabetes insipidus occurs in patients with overwhelming central nervous system injuries, and may be associated with brain death. The clinical picture of children with acquired central diabetes insipidus after acute brain insult is seldom reported. We retrospectively reviewed cases dating from January 2000-February 2008 at a tertiary pediatric intensive care unit. Fifty-four patients (28 girls, 26 boys), aged 3 months to 18 years, were enrolled. Etiologies included severe central nervous system infection (35.2%), hypoxic-ischemic events (31.5%), head injury (18.5%), and vascular lesions (14.8%). In 39 (72.2%) patients, diabetes insipidus was diagnosed during the first 2 days after acute central nervous system injury, and 40 (74.0%) developed maximum serum sodium concentrations of >160 mEq/L. In 16, sequential cerebral salt wasting syndrome developed after their initial diabetes insipidus presentation. Overall mortality at 2 months after admission was 77.8%. Our results demonstrate that patients who develop central diabetes insipidus after acute central nervous system injury manifest high mortality. Development of central diabetes insipidus within the first 2 days and a maximum plasma sodium >160 mEq/L were significant predictors of outcomes.

Hyponatremia and brain injury: absence of alterations of serum brain natriuretic peptide and vasopressin

OBJECTIVE

To study any possible relation between hyponatremia following brain injury and the presence of cerebral salt-wasting syndrome (CSWS) or the syndrome of inappropriate secretion of antidiuretic hormone (SIADH), and if vasopressin, brain natriuretic peptide (BNP) and aldosterone have a role in its mechanism.

METHOD

Patients with brain injury admitted to the intensive care unit were included and had their BNP, aldosterone and vasopressin levels dosed on day 7.

RESULTS

Twenty six adult patients were included in the study. Nine (34.6%) had hyponatremia and presented with a negative water balance and higher values of urinary sodium, serum potassium and diuresis than patients with normonatremia. The serum levels of BNP, aldosterone, and vasopressin were normal and no relation was observed between plasma sodium and BNP, aldosterone or vasopressin.

CONCLUSION

The most likely cause of hyponatremia was CSWS and there was no correlation between BNP, aldosterone and vasopressin with serum sodium level.

Cerebral salt wasting: pathophysiology, diagnosis, and treatment

Cerebral salt wasting (CSW) is a syndrome of hypovolemic hyponatremia caused by natriuresis and diuresis. The mechanisms underlying CSW have not been precisely delineated, although existing evidence strongly implicates abnormal elevations in circulating natriuretic peptides. The key in diagnosis of CSW lies in distinguishing it from the more common syndrome of inappropriate secretion of antidiuretic hormone. Volume status, but not serum and urine electrolytes and osmolality, is crucial for making this distinction. Volume and sodium repletion are the goals of treatment of patients with CSW, and this can be performed using some combination of isotonic saline, hypertonic saline, and mineralocorticoids.

Intraoperative hyponatremia during craniofacial surgery

BACKGROUND

Hyponatremia is an important cause of morbidity in some groups of hospitalized children. Our aim is to describe the incidence and severity of intraoperative hyponatremia in children undergoing craniofacial surgery, and determine the associated risk factors.

METHODS

A descriptive retrospective study of children who underwent primary craniofacial surgery between March 1994 and February 2008 was performed. All administered fluids contained a minimum sodium concentration of 140 mmol.l(-1). Hyponatremia was classified as follows: severe < or =125 mmol.l(-1); moderate 126-130 mmol.l(-1); and, mild 131-134 mmol.l(-1).

RESULTS

Hundred and seven cases are reported. Severe, moderate and mild intraoperative hyponatremia occurred in 14 (13%), 21 (19%) and 23 (22%) children respectively. Mannitol was given to 31 (29%) children, but was not associated with the development of hyponatremia. Neither the type nor duration of surgery, type of fluid replacement nor hourly urinary output, was associated with development of hyponatremia. Most episodes of significant intraoperative hyponatremia (44%) were detected between the 2nd and the 4th hour of surgery. There were no identified neurological sequelae (e.g. coma, neurological deficit) attributable to the hyponatremia.

CONCLUSION

Despite strict avoidance of low sodium solutions (<140 mmol.l(-1)), hyponatremia occurs frequently in children undergoing craniofacial surgery in our practice; and is unrelated to the administration of mannitol. Although the mechanisms are yet to be determined, anesthesiologists should be aware of this issue and be prepared to monitor and treat this potentially serious complication.

Combined central diabetes insipidus and cerebral salt wasting syndrome in children

Central diabetes insipidus, a common consequence of acute central nervous system injury, causes hypernatremia; cerebral salt wasting syndrome can cause hyponatremia. The two conditions occurring simultaneous are rarely described in pediatric patients. Pediatric cases of combined diabetes insipidus and cerebral salt wasting after acute central nervous system injury between January 2000 and December 2007 were retrospectively reviewed, and clinical characteristics were systemically assessed. Sixteen patients, aged 3 months to 18 years, met study criteria: 11 girls and 5 boys. The most common etiologies were severe central nervous system infection (n = 7, 44%) and hypoxic-ischemic event (n = 4, 25%). In 15 patients, diabetes insipidus was diagnosed during the first 3 days after acute central nervous system injury. Onset of cerebral salt wasting syndrome occurred 2-8 days after the onset of diabetes insipidus. In terms of outcome, 13 patients died (81%) and 3 survived under vegetative status (19%). Central diabetes insipidus and cerebral salt wasting syndrome may occur after acute central nervous system injury. A combination of both may impede accurate diagnosis. Proper differential diagnoses are critical, because the treatment strategy for each entity is different.

The effects of head trauma on hypothalamic-pituitary function in children and adolescents

PURPOSE OF REVIEW

Endocrine dysfunctions have been increasingly recognized following traumatic brain injury. Ever more numerous studies on acute head-injured adults have also raised concern about this risk in children and adolescents who have experienced head injury. The current review of the pediatric literature summarizes recent findings on acute-phase dysfunction and traumatic brain injury-associated hypopituitarism.

RECENT FINDINGS

The pathophysiologic mechanisms underlying acute-phase hyponatremic and hypernatremic disorders have been elucidated. Prospective studies on traumatic brain injury-associated hypopituitarism in pediatric patients are ongoing and preliminary data are available.

SUMMARY

Traumatic brain injury, a 'silent epidemic' that carries a considerable burden of disabilities, leads to a variety of endocrine dysfunctions in 28-69% of adult acute head-injured patients. In the acute posttraumatic phase, adrenal insufficiency and electrolyte disorders are critical conditions. Neurosurgical patients, particularly those prone to neurological damage, require prompt diagnosis. Hypopituitarism may be diagnosed months or years after a traumatic brain injury event. Since growth hormone and gonadotropin secretion are most frequently compromised, careful follow-up of growth and pubertal development is mandatory in children hospitalized for traumatic brain injury.