Hyponatraemia and seizures in oncology patients associated with hypotonic intravenous fluids

Choice of maintenance intravenous fluids among paediatric residents in Canada

Background

Recent literature and guidelines support routine use of isotonic intravenous (IV) fluids for maintenance therapy in hospitalized infants and children. Current prescribing practices are unknown.

Objective

To elicit paediatric residents' choice of maintenance IV fluids, particularly with regard to tonicity, in a variety of clinical scenarios and patient ages. We hypothesized that residents would choose isotonic fluids in most cases, but there would be substantially more variability in fluid choice in the neonatal age group.

Methods

An Internet-based survey was e-mailed to trainees in the 17 paediatric residency programs across Canada, via the Canadian Paediatric Program Directors. The survey instrument included questions related to training, followed by a series of questions eliciting choice of IV fluid in a variety of clinical situations.

Results

A total of 147 survey responses were submitted (22% response rate). Isotonic solutions were selected by >75% across all clinical scenarios involving infants and children. Very hypotonic fluids were seldom chosen. There was more variability in fluid choice in neonates, with evidence of significant differences in fluid tonicity based on senior versus junior resident status and geographical location.

Conclusions

Results imply a predominance of isotonic fluid use in infants and children, suggesting that clinical practice has changed in response to risk of hyponatremia with hypotonic IV fluids. As hypothesized, there was more variability with respect to choice of maintenance fluids in neonates. This likely reflects a paucity of guidance in an age group with unique physiologic factors affecting fluid and electrolyte status.

Clinical Practice Guideline: Maintenance Intravenous Fluids in Children

Maintenance intravenous fluids (IVFs) are used to provide critical supportive care for children who are acutely ill. IVFs are required if sufficient fluids cannot be provided by using enteral administration for reasons such as gastrointestinal illness, respiratory compromise, neurologic impairment, a perioperative state, or being moribund from an acute or chronic illness. Despite the common use of maintenance IVFs, there is high variability in fluid prescribing practices and a lack of guidelines for fluid composition administration and electrolyte monitoring. The administration of hypotonic IVFs has been the standard in pediatrics. Concerns have been raised that this approach results in a high incidence of hyponatremia and that isotonic IVFs could prevent the development of hyponatremia. Our goal in this guideline is to provide an evidence-based approach for choosing the tonicity of maintenance IVFs in most patients from 28 days to 18 years of age who require maintenance IVFs. This guideline applies to children in surgical (postoperative) and medical acute-care settings, including critical care and the general inpatient ward. Patients with neurosurgical disorders, congenital or acquired cardiac disease, hepatic disease, cancer, renal dysfunction, diabetes insipidus, voluminous watery diarrhea, or severe burns; neonates who are younger than 28 days old or in the NICU; and adolescents older than 18 years old are excluded. We specifically address the tonicity of maintenance IVFs in children.The Key Action Statement of the subcommittee is as follows:1A: The American Academy of Pediatrics recommends that patients 28 days to 18 years of age requiring maintenance IVFs should receive isotonic solutions with appropriate potassium chloride and dextrose because they significantly decrease the risk of developing hyponatremia (evidence quality: A; recommendation strength: strong).

Full Volume Isotonic (0.9%) vs. Two-Thirds Volume Hypotonic (0.18%) Intravenous Maintenance Fluids in Preventing Hyponatremia in Children Admitted to Pediatric Intensive Care Unit-A Randomized Controlled Study

BACKGROUND

We aimed to compare the effect of two different intravenous fluid regimes on the incidence of hyponatremia in children.

METHODS

Children 1 month to 18 years of age, admitted to pediatric intensive care unit (PICU) of a tertiary care medical college hospital were randomized to receive either isotonic fluid (0.9% saline in 5% dextrose) at the standard maintenance rate or hypotonic fluid (0.18% saline in 5% dextrose) at two-thirds of the standard maintenance rate.

RESULTS

A total of 240 children were randomized (120 isotonic, 120 hypotonic). In all, 16.7% children in hypotonic group developed hyponatremia compared with 7.5% in isotonic group (p = 0.029). Duration of PICU stay was significantly more in Hypotonic group.

CONCLUSION

We conclude that use of 0.9% saline in 5% dextrose as maintenance fluid helps in reducing the incidence of hospital-acquired hyponatremia and duration of intensive care unit stay among children admitted to PICU.

Severe Hyponatremia in a Single-Center Series of 84 Homogenously Treated Children With Acute Lymphoblastic Leukemia

Electrolyte abnormalities are hallmark metabolic disturbances during the treatment of acute lymphoblastic leukemia (ALL). Hyponatremia is an ominous laboratory sign in the setting of neoplasia. We analyzed the incidence, risk factors, associations, specific interventions and outcomes of severe hyponatremia in a single-center series of children with ALL. The incidence of severe hyponatremia, defined as serum sodium levels below 130 mmol/L on at least 2 of 3 consecutive days, was 11.9%. History of hyponatremia episode is associated with neurologic complications (P=0.023) and the presence of overt central nervous system leukemia (CNS3) at diagnosis (P=0.005). Most observed hyponatremia episodes resolved relatively quickly, rarely requiring specific treatment. All but 1 hyponatremia episodes occurred in the induction or reinduction phases, but none before the administration of cytotoxic drugs, pointing to the role of therapy complications rather than leukemia per se. Most patients received vincristine shortly before hyponatremia onset, and vincristine has been previously strongly implicated in hyponatremia. We also suggest a role for imatinib. Although every patient with severe hyponatremia requires swift and thorough diagnostics a serious sequelae in the setting of pediatric ALL is rare. Hyponatremia association with neurotoxicity likely points to vincristine hypersensitivity in the subgroup of patients with both complications.

Incidence, Severity, and Association With Adverse Outcome of Hyponatremia in Children Hospitalized With Heart Failure

Hyponatremia is a common finding in adults hospitalized with heart failure (HF) and is associated with longer hospital stays and increased mortality. The significance of hyponatremia in children with HF is not known. We sought to determine the incidence of hyponatremia and association with clinical outcome in children hospitalized with HF. Admission and inpatient serum sodium concentrations were analyzed in 141 consecutive children hospitalized with acute decompensated HF. Inclusion criteria include patients (age, birth to 21 years) with biventricular hearts who were hospitalized for HF from January 2007 to December 2012. The primary composite end point was death, cardiac transplantation, or the use of mechanical circulatory support (MCS) during hospitalization. Data for 141 patients were included in the analysis. The cohort included 48 patients (34%) with preexisting HF. Mean serum sodium at admission was 136 ± 4 mmol/L (range 124 to 150 mmol/L). Hyponatremia (serum sodium <135 mmol/L) was present in 45 patients (32%) at admission. Seventy-one patients (75%) with normal serum sodium concentrations at admission subsequently developed acquired hyponatremia during their hospitalization. Hyponatremia persisted at discharge in 17 of 66 patients (26%). Fifty-eight patients (41%) reached the composite end point during hospitalization (death, n = 15; cardiac transplantation, n = 27; MCS, n = 46). Hyponatremia at admission was independently associated with death, cardiac transplantation, or the use of MCS during hospitalization (odds ratio 3.1, p = 0.02). In conclusion, hyponatremia occurs commonly in children hospitalized with acute decompensated HF and is associated with increased risk of in-hospital mortality, cardiac transplantation, and need for MCS.

Neurological symptoms in hospitalised patients: do we assess hyponatraemia with sufficient care?

AIM

To review the incidence of hyponatraemic encephalopathy in children treated in a tertiary care centre hospital, together with the clinical setting and clinical management of these cases.

METHODS

Retrospective descriptive study by chart review of patients admitted to hospital during 2000-2010. Patients older than 1 month were included who had severe hyponatraemia (sodium concentration <125 mmol/L) on admission or during their hospital stay and co-incidental neurological symptoms. Epidemiological, clinical, laboratory and therapeutic data were collected.

RESULTS

We analysed 41 cases of severe hypotonic hyponatraemia and neurological symptoms compatible with hyponatraemic encephalopathy. Boys accounted for 56.1% patients, and the median age was 1 year. Hyponatraemia was acquired in hospital by 61% of the patients, and 88% of those patients were receiving intravenous hypotonic fluids. The most frequent neurological symptom was seizures. The most common therapeutic strategy was sodium supplementation and antiepileptic drugs. Hypertonic fluids were only used in the initial treatment of 16 patients. There were two deaths related to hyponatraemic encephalopathy.

CONCLUSION

Hyponatraemia should always be considered a cause of neurological symptoms in hospitalised patients. Treatment should be prompt to prevent neurological sequelae and death. Current recommendations for fluid management in hospitalised children should be reviewed.

New aspects in the pathogenesis, prevention, and treatment of hyponatremic encephalopathy in children

Hyponatremia is the most common electrolyte abnormality encountered in children. In the past decade, new advances have been made in understanding the pathogenesis of hyponatremic encephalopathy and in its prevention and treatment. Recent data have determined that hyponatremia is a more serious condition than previously believed. It is a major comorbidity factor for a variety of illnesses, and subtle neurological findings are common. It has now become apparent that the majority of hospital-acquired hyponatremia in children is iatrogenic and due in large part to the administration of hypotonic fluids to patients with elevated arginine vasopressin levels. Recent prospective studies have demonstrated that administration of 0.9% sodium chloride in maintenance fluids can prevent the development of hyponatremia. Risk factors, such as hypoxia and central nervous system (CNS) involvement, have been identified for the development of hyponatremic encephalopathy, which can lead to neurologic injury at mildly hyponatremic values. It has also become apparent that both children and adult patients are dying from symptomatic hyponatremia due to inadequate therapy. We have proposed the use of intermittent intravenous bolus therapy with 3% sodium chloride, 2 cc/kg with a maximum of 100 cc, to rapidly reverse CNS symptoms and at the same time avoid the possibility of overcorrection of hyponatremia. In this review, we discuss how to recognize patients at risk for inadvertent overcorrection of hyponatremia and what measures should taken to prevent this, including the judicious use of 1-desamino-8d-arginine vasopressin (dDAVP).

Clinical profile of hospitalized children provided with urgent assistance from a medical emergency team

OBJECTIVE

The purpose of this work was to describe the frequency, characteristics, and outcomes of critical events and hospitalized children requiring medical emergency team review.

PATIENTS AND METHODS

We conducted an audit of prospectively collected medical emergency team forms and a retrospective review of medical charts during an 18-month period at a tertiary pediatric hospital in Australia. Critical events were defined as cardiac arrest, endotracheal intubation on the ward, reversal of analgesia or sedation, fluid resuscitation at >/=40 mL/kg, hyponatremia (serum sodium level of </=125 mmol/L), hypernatremia (serum sodium level of >/=155 mmol/L), hypoglycemia (glucose level of </=2 mmol/L), or severe metabolic acidosis (pH </= 7.1).

RESULTS

A total of 172 children had 225 medical emergency team calls (10.6 calls per 1000 hospital admissions and 2.0 calls per 1000 patient-days). Forty-two percent of calls were for infants <1 year old. Preexisting chronic disease was common, with 20% having a chronic underlying neurologic disorder. Forty-four percent of the children were postoperative. The mortality rate of the 172 children was 7.6% in the hospital and 13.4% within 1 year. Thirty-three children had a critical event, with reversal of analgesia being the most common event (n = 11). Postoperative children were more frequently seen in the critical-event group (64% vs 40%). Hospital and 1-year mortality rates were higher for children who had a critical event (16.1% vs 22.6%, respectively) than those who did not (5.7% vs 11.3%).

CONCLUSIONS

Chronic and complex illnesses were prevalent among children provided with urgent medical assistance from the medical emergency team in a tertiary hospital. Children in the postoperative phase were overrepresented among those with a critical event. A critical event significantly increased the risk of hospital mortality. Greater knowledge of high-risk groups is required to further improve outcomes for hospitalized children.

Tumor-related hyponatremia

Hyponatremia is an important and common electrolyte disorder in tumor patients and one that has been reported in association with a number of different primary diagnoses. The correct diagnosis of the pathophysiological basis for each patient is important because it significantly alters the treatment approach. In this article, we review the epidemiology and presentation of patients with hyponatremia, the pathophysiologic groups for the disorder with respect to sodium and water balance and the diagnostic measures for determining the correct pathophysiologic groups. We then present the various treatment options based on the pathophysiologic groups including a mathematical approach to the use of hypertonic saline in management. In cancer patients, hyponatremia is a serious comorbidity that requires particular attention as its treatment varies by pathophysiologic groups, and its consequences can have a deleterious effect on the patient's health.