Non-accidental salt poisoning

Challenges in using fractional excretion of sodium in the assessment of salt poisoning

AIM

Hypernatraemia typically reflects dehydration, yet in rare instances may be caused by salt poisoning. Identifying these rare cases is a difficult challenge. Making the diagnosis of salt poisoning can have severe consequences, such as the removal of the child from its home or even prison sentences for the implicated carer. It is therefore imperative to get the diagnosis right. Guidelines for the assessment of hypernatraemia emphasise the importance of the fractional excretion of sodium to distinguish between dehydration and salt poisoning, but no generally accepted cut-off value exists. Opinions about the diagnosis of salt poisoning in some cases consequently may differ. Here, we aim to highlight the challenges and stimulate discussion on how to improve the tools for the assessment of hypernatraemia.

METHODS

Report of a case of unexplained hypernatraemia in which the treating paediatrician raised the suspicion of salt poisoning.

RESULTS

Two consulted experts made opposing judgements about the aetiology of the observed hypernatraemia.

CONCLUSION

Clear diagnostic criteria for the diagnosis of salt poisoning are lacking and more data are needed for their establishment. Without this, victims may experience further harm and carers are at risk of devastating, yet potentially erroneous accusations.

Recognition and Management of Pediatric Salt Toxicity

OBJECTIVES

Immediate recognition of salt toxicity and aggressive resuscitative measures are critical in the treatment of this lethal poisoning. Despite heroic measures, pediatric deaths due to salt toxicity still occur from irreversible neurological damage. The objective of this article is to review the relevant literature and offer a therapeutic algorithm for the management of pediatric patients presenting with salt toxicity.

METHODS

A literature search for cases of salt toxicity was conducted. Articles in English that were available electronically through PubMed and Google Scholar were reviewed.

RESULTS

Nineteen cases and case series of salt toxicity were located using our search strategy. Salt poisoning has a distinct pathophysiology compared with hypernatremia, most notable for the lack of formation of idiogenic osmoles.

CONCLUSIONS

The approach to treatment differs between salt toxicity and hypernatremia, focusing on rapid correction of serum osmolality rather than gradual normalization of serum sodium concentrations. Consultation of nephrology and child protection services are strongly recommended in the comprehensive treatment approach.

Hong Kong Poison Information Centre: Annual Report 2011

Objective

To report and analyse the poisoning data of Hong Kong Poison Information Centre (HKPIC) in 2011.

Methods

In 2011, all poisoning cases received by HKPIC were retrieved from its database: Poison Information and Clinical Management System (PICMS) for analysis.

Results

A total of 4,331 poisoned cases were analysed. There were 1,915 male patients (44.2%), 2,411 female patients (55.7%) and 5 patients with sex unknown. More than two-third (68%) of them were between 20 and 59 years old. Common causes of exposure were suspected self-harm/suicidal attempt, unintentional exposure and abusive use. Paracetamol, benzodiazepine, household product, zopiclone, and Chinese herbal medicine were the top five commonest poisons encountered. Majority of the patients were managed supportively, with 12.1% and 8.5% treated by decontamination and antidotes respectively. Most cases had uneventful recovery; 1.0% of the poison exposure resulted in death and 4.8% of the exposure had major outcomes.

Conclusions

This 6th annual report provided updated epidemiological information on poisoning pattern in Hong Kong and emphasized some changes in comparing with our previous reports.

A Systematic Review of Fatalities Related to Acute Ingestion of Salt. A Need for Warning Labels?

There are sporadic cases of fatalities from acutely eating salt. Yet, on social media, there are "challenges to" and examples of children and some adults acutely eating salt, and recently a charity advocated eating small amounts of salt to empathize with Syrian refugees. We performed a systematic review of fatalities from ingesting salt to assess if relatively moderate doses of salt could be fatal. In 27 reports, there were 35 fatalities documented (19 in adults and 16 in children). The lethal dose was estimated to be less than 10 g of sodium (<5 teaspoons of salt) in two children, and less than 25 g sodium in four adults (<4 tablespoons of salt). The frequency of fatal ingestion of salt is not able to be discerned from our review. If investigation of the causes of hypernatremia in hospital records indicates salt overdose is relatively common, consideration could be given to placing warning labels on salt containers and shakers. Such warning labels can have the added advantage of reducing dietary salt consumption.

Hyperosmolar sodium chloride is toxic to cultured neurons and causes reduction of glucose metabolism and ATP levels, an increase in glutamate uptake, and a reduction in cytosolic calcium

Elevation of serum sodium, hypernatremia, which may occur during dehydration or treatment with sodium chloride, may cause brain dysfunction and damage, but toxic mechanisms are poorly understood. We found that exposure to excess NaCl, 10-100mmol/L, for 20h caused cell death in cultured cerebellar granule cells (neurons). Toxicity was due to Na(+), since substituting excess Na(+) with choline reduced cell death to control levels, whereas gluconate instead of excess Cl(-) did not. Prior to cell death from hyperosmolar NaCl, glucose consumption and lactate formation were reduced, and intracellular aspartate levels were elevated, consistent with reduced glycolysis or glucose uptake. Concomitantly, the level of ATP became reduced. Pyruvate, 10mmol/L, reduced NaCl-induced cell death. The extracellular levels of glutamate, taurine, and GABA were concentration-dependently reduced by excess NaCl; high-affinity glutamate uptake increased. High extracellular [Na(+)] caused reduction in intracellular free [Ca(2+)], but a similar effect was seen with mannitol, which was not neurotoxic. We suggest that inhibition of glucose metabolism with ensuing loss of ATP is a neurotoxic mechanism of hyperosmolar sodium, whereas increased uptake of extracellular neuroactive amino acids and reduced intracellular [Ca(2+)] may, if they occur in vivo, contribute to the cerebral dysfunction and delirium described in hypernatremia.

Severe hypernatremia by excessive bamboo salt ingestion in healthy young woman

Severe hypernatremia is an important electrolyte disorder that has serious effects. The patient had no medical history. A. 20-year-old ingested bamboo salt for digestion and weight reduction according to the folk remedies posted on an internet website. She presented with vomiting and diarrhea over ten times per day. Her initial serum sodium concentration was 174mEq/L. Her symptoms improved rapidly with hypotonic saline infusion. She recovered completely without any sequelae in three days. Severe hypernatremia in a normal young adult with clear consciousness and normal renal function has not been reported in Korea yet. So we report a case of severe hypernatremia by excessive bamboo salt ingestion in healthy young woman.

Munchausen syndrome and factitious disorder: the role of the laboratory in its detection and diagnosis

The term Munchausen syndrome is used to describe the patient who chronically fabricates or induces illness with the sole intention of assuming the patient role. Such persons often have a close association with the medical profession and thus use their knowledge to falsify symptoms and laboratory specimens to mimic disease. Cases of factitious disease have appeared in the literature originating from all medical specialties, and include such rare disorders as phaeochromocytoma and Bartter's syndrome. The laboratory can play a key role in the detection and diagnosis of factitious disorders. Indeed discrepant biochemistry results may provide the first clue to the diagnosis. Laboratory staff should be particularly aware of highly variable test results and extreme abnormalities that are not consistent with the wider biochemical profile, suggesting sample tampering. Factitious disorder should also be included in the clinician's differential diagnosis when disease presentation is unusual or an underlying cause cannot be found. Investigation to exclude or confirm factitious disorder at an early stage can prevent unnecessary testing in the search for increasingly rare diseases. Appropriate analyses may include screening tests for the detection of surreptitious drug administration or replication of a fabricated sample to confirm the method used. In all cases close communication between the clinician and laboratory is essential. This will ensure that appropriate tests are conducted particularly with regard to time critical and repeat tests.

A clinical approach to the treatment of chronic hypernatremia

Hypernatremia is a commonly encountered electrolyte disorder occurring in both the inpatient and outpatient settings. Community-acquired hypernatremia typically occurs at the extremes of age, whereas hospital-acquired hypernatremia affects patients of all age groups. Serum sodium concentration is linked to water homeostasis, which is dependent on the thirst mechanism, arginine vasopressin, and kidney function. Because both hypernatremia and the rate of correction of hypernatremia are associated with significant morbidity and mortality, prompt effective treatment is crucial. Chronic hypernatremia can be classified into 3 broad categories, hypovolemic, euvolemic, and hypervolemic forms, with each form having unique treatment considerations. In this teaching case, we provide a clinically based quantitative approach to the treatment of both hypervolemic and hypovolemic hypernatremia, which occurred in the same patient during the course of a prolonged illness.

Severe hypernatremia in a hospitalized child: munchausen by proxy

An 8-week-old infant presented to a referring institution with profuse diarrhea and infectious enteritis for 1 week. He was initially treated for suspected Salmonella spp. sepsis and meningitis, because the organism was found in the stool, but the child's illness progressed, manifested by paroxysmal profuse diarrhea and increased urine output. After several weeks, he suffered a sagittal venous thrombosis and intracranial hemorrhage. Subsequently the child was transferred to a tertiary center for intestinal evaluation. The patient's diarrhea and excessive diuresis resolved, and his sodium normalized soon after transfer. Four days later, however, after his mother arrived, he immediately developed severe hypernatremia (serum sodium concentration [Na(+)] = 214 mEq/L), with resumption of diarrhea and excessive diuresis. A gastric aspirate during the crisis demonstrated an extremely high sodium content, [Na(+)] = 1416 mEq/L, consistent with salt intoxication. Surveillance of the mother revealed that she manipulated the indwelling nasogastric tube; confronted, she admitted to salt administration. This case describes one of the ways that Munchausen syndrome by proxy can manifest with profound neurologic sequelae, and highlights the need for close observation and swift intervention when sufficient cause is present.

A review of drug-induced hypernatraemia

Drug-induced electrolyte abnormalities have been increasingly reported and may be associated with considerable morbidity and/or mortality. In clinical practice, hypernatraemia (serum sodium higher than 145 mmol/L) is usually of multifactorial aetiology and drug therapy not infrequently is disregarded as a contributing factor for increased serum sodium concentration. Strategies to prevent this adverse drug effect involve careful consideration of risk factors and clinical and laboratory evaluation in the course of treatment. Herein, we review evidence-based information via PubMed and EMBASE and the relevant literature implicating pharmacologic treatment as an established cause of hypernatraemia and discuss its incidence and the underlying pathophysiologic mechanisms.

Munchausen syndrome by proxy

Munchausen Syndrome by Proxy has been recognised for almost two decades. This review considers the definition, clinical features, consequences (to both victim and perpetrator), diagnosis and outcome of the syndrome.

Criminal Poisoning: Munchausen by Proxy

The diagnosis and subsequent prosecution of Munchausen by proxy (MBP) cases require the collaborative teamwork of health care teams, laboratory personnel, law enforcement, and social services. Poisoning occurs in a significant number of the MBP cases with a diverse variety of agents used. To aid laboratory professionals in determining the appropriate toxicology tests to perform in such criminal cases, health care professionals must focus their testing requests on substances that correspond to the victim's signs, symptoms, and ancillary test values. This article reviews MBP, with particular focus on poisoning agents that have been used in past reported cases.

An explanatory model for Munchausen by proxy abuse

OBJECTIVE

In Munchausen by proxy (MBP) abuse, a caretaker fabricates or induces illness in another person to obtain emotional gratification. In representative cases, a mother is the perpetrator and her child is the victim. In view of the limits of current explanatory models, we use personal accounts of MBP perpetrators, physicians, and family members as a window into understanding this counterintuitive behavior.

METHOD

As subspecialty clinicians and consultants, we supplemented our extensive direct experience with MBP with a review of published reports of MBP located via MEDLINE and PsycINFO (1980 onward). We also examined the books devoted to the subject and incorporated personal accounts of MBP perpetrators and of family members and professionals involved with them.

RESULTS

Factors contributing to the onset and continuation of MBP are the perpetrator's experiencing a particular drive (e.g., intense anger or frustration); lacking or overcoming internal inhibitions against abusive actions; and overcoming external inhibitions, such as the potential intercession of a spouse or pediatrician. As a result, the MBP parent experiences release from unpleasant emotions and a sense of renewed control. MBP behavior gains "habit strength" each time it occurs.

CONCLUSIONS

Psychodynamic explanations of MBP, while favored by some authors, are inherently speculative and tend to be low in predictive value. We suggest broadening these traditional explanations by emphasizing observable behaviors and verifiable background factors. The behavioral perspective we outline helps explain how MBP behavior is learned, why it is more prevalent among mothers, and why it is so difficult for perpetrators to stop.

Two siblings poisoned with diphenhydramine: a case of factitious disorder by proxy

We report a case of factitious disorder by proxy (FDBP), formerly known as Munchausen syndrome by proxy, in which 2 siblings were poisoned with diphenhydramine. Although diphenhydramine is a readily available medication, no report of its use as the sole agent in an FDBP case was found in a literature search. Although sibling involvement in FDBP is well documented, this is the first case report of 2 siblings hospitalized simultaneously because of intentional poisoning with the same substance. Finally, the use of physostigmine to definitively diagnose anticholinergic poisoning in a case of FDBP has not previously been described.

Munchausen syndrome by proxy

Munchausen syndrome by proxy is the most difficult form of child abuse. It carries substantial morbidity and mortality. The diagnosis relies on appropriate suspicion and careful investigation. The psychological illness/need of the perpetrator is the main clinical feature. Early recognition and appropriate intervention prevent further abuse and criminal actions.

Clinical and toxicological findings in two young siblings and autopsy findings in one sibling with multiple hospital admissions resulting in death. Evidence suggesting Munchausen syndrome by proxy

A 15-month-old girl underwent several emergency department (ED) visits and two admissions for parent-reported histories of ingestions, apnea, and seizures. She was initially admitted following reports of several unusual episodes of syncope accompanied by convulsive movements and was discharged on mephobarbital with a diagnosis of atypical seizure disorder. The day after discharge, she was brought to the ED in cardiopulmonary arrest and was resuscitated after a prolonged period. She was declared brain dead 2 days later. Ante- and postmortem toxicology produced several inconclusive findings, none of which explained death. Autopsy findings, including neuropathology, failed to demonstrate any significant disease processes. Approximately 3 months later, a 4-month-old female sibling was brought to the ED with a parent-reported history of apnea and seizures similar to the deceased child. A stool specimen obtained 2 days after admission contained numerous tiny seeds, which were found by gas chromatography-mass spectrometry analysis to contain lorazepam and temazepam. The role of these benzodiazepines in the apnea episodes in this infant was unknown, but the presence of the seeds in such a young infant coupled with the parent's aberrant behavior, led to the tentative diagnosis of Munchausen syndrome by proxy. This diagnosis was strengthened when results from these studies persuaded legal authorities to remove the surviving sibling from the parents, resulting in an asymptomatic recovery.

[Recurrent ingestion of foreign bodies. Unusual presentation of Munchausen by Proxy syndrome]

A case with unusual presentation of Munchausen syndrome by proxy is reported. It was shown through reiterated ingestion of foreign bodies (two earrings, probably a button but not confirmed, a 5 cm. screw and two sewing needles) perpetrated by a 22-year-old mother with a psychiatric record of behavior disorders and family dysfunctions on a 10-month-old infant with a history of prematurity, repeated visits to emergency rooms, and nonjustified multiple hospital admissions. The difficulties in the diagnosis and the need for an early detection are brought up, making considerations in regard to indicators, diagnostic criteria, and management procedure.

Follow up of victims of fabricated illness (Munchausen syndrome by proxy)

Fifty four children were studied 1-14 (mean 5.6) years after fabrications of illness had been identified. Thirty of the 54 children were living in families with their biological mothers and 24 were with other family members or in substitute families. Further fabrications were identified for 10 children who had been living with their mothers and there were 'other concerns' for a further eight children. Thirteen children residing with mother and 14 not residing with mother at follow up had a range of disorders including conduct and emotional disorders, and problems related to school, including difficulties in attention and concentration and non-attendance. Overall, 20 children (49% of those successfully followed up) had outcomes that were considered to be unacceptable.