Review of the literature: severe hyperphosphatemia

Starvation hepatitis and refeeding-induced hepatitis: mechanism, diagnosis, and treatment

Anorexia nervosa (AN) is one of the most common psychiatric disorders among young adults and is associated with a substantial risk of death from suicide and medical complications. Transaminase elevations are common in patients with AN at the time of hospital admission and have been associated with longer lengths of hospital stay. Multiple types of hepatitis may occur in these patients, including two types that occur only in patients with AN: starvation hepatitis and refeeding-induced hepatitis. Starvation hepatitis is characterized by severe transaminase elevation in patients in the advanced phase of protein-energy deprivation and is associated with complications of severe starvation, such as hypoglycaemia, hypothermia, and hypotension. Refeeding-induced hepatitis is characterized by a milder increase in transaminases that occurs in the early refeeding phase and is associated with hypophosphatemia, hypokalemia, and hypomagnesaemia. Among the most common forms of hepatitis, drug-induced liver injury is particularly relevant in this patient cohort, given the frequent use and abuse of methamphetamines, laxatives, antidepressants, and antipsychotics. In this review, we provided an overview of the different forms of anorexic-associated hepatitis, a diagnostic approach that can help the clinician to correctly frame the problem, and indications on their management and treatment.

Relationship Between the Anion Gap and Serum Lactate in Hypovolemic Shock

Background and objectives: Previous studies evaluating patients in the Intensive Care Unit with established lactic acidosis determined that the anion gap is an insensitive screening tool for elevated blood lactate. No prior study has examined the relationship between anion gap and serum lactate within the first hours of the development of lactic acidosis. Design, setting, participants, & measurements: Data were obtained prospectively from a convenience sample of adult trauma patients at a single level 1 trauma center. Venous samples were drawn prior to initiation of intravenous fluid resuscitation. A linear regression model was constructed to assess the relationship between serum lactate and anion gap, and 95% prediction intervals were computed. Logistic regression models were constructed to determine the sensitivity and specificity for several different anion gap and lactate cutpoints. Results: 128 patients with elevated serum lactate levels (>2.1 mmol/L) and 63 patients with normal serum lactate levels (< 2.1 mmol/L) were included. The sensitivity of an elevated anion gap (> 10) to reveal hyperlactatemia was only 43% whereas specificity was 84%. Sensitivity improved if the upper limit of normal anion gap was lowered and with increasing levels of serum lactate. The coefficient of determination between serum lactate level and AG yielded an R2 of 0.30 (p < 0.001) and the slope of this relationship was 2.185 with a 95% confidence interval of 2.011-2.359. The mean 95% prediction interval was + 8.9. Conclusions: Within the first hour of the development of lactic acidosis due to hypovolemic shock, the anion gap was not a sensitive indicator of an elevated serum lactate level, but it was fairly specific. The anion gap increased to a greater extent than the serum lactate, the 95% mean prediction interval was wide and approximately 70% of the change in anion gap could not be explained by increases in serum lactate, suggesting that other anions contribute to the anion gap in lactic acidosis.

Management of Refeeding Syndrome in Medical Inpatients

Refeeding syndrome (RFS) is the metabolic response to the switch from starvation to a fed state in the initial phase of nutritional therapy in patients who are severely malnourished or metabolically stressed due to severe illness. It is characterized by increased serum glucose, electrolyte disturbances (particularly hypophosphatemia, hypokalemia, and hypomagnesemia), vitamin depletion (especially vitamin B1 thiamine), fluid imbalance, and salt retention, with resulting impaired organ function and cardiac arrhythmias. The awareness of the medical and nursing staff is often too low in clinical practice, leading to under-diagnosis of this complication, which often has an unspecific clinical presentation. This review provides important insights into the RFS, practical recommendations for the management of RFS in the medical inpatient population (excluding eating disorders) based on consensus opinion and on current evidence from clinical studies, including risk stratification, prevention, diagnosis, and management and monitoring of nutritional and fluid therapy.

Refeeding syndrome in the frail elderly population: prevention, diagnosis and management

Aging is linked to physiological and pathophysiological changes. In this context, elderly patients often are frail, which strongly correlates with negative health outcomes and disability. Elderly patients are often malnourished, which again is an independent risk factor for both frailty and adverse clinical outcomes. Malnutrition and resulting frailty can be prevented by adequate nutritional interventions. Yet, use of nutritional therapy can also have negative consequences, including a potentially life-threatening metabolic alteration called refeeding syndrome (RFS) in high-risk patients. RFS is characterized by severe electrolyte shifts (mainly hypophosphatemia, hypomagnesemia and hypokalemia), vitamin deficiency (mainly thiamine), fluid overload and salt retention leading to organ dysfunction and cardiac arrhythmias. Although the awareness of malnutrition among elderly people is well established, the risk of RFS is often neglected, especially in the frail elderly population. This partly relates to the unspecific clinical presentation and laboratory changes in the geriatric population. The aim of this review is to summarize recently published recommendations for the management of RFS based on current evidence from clinical studies adapted with a focus on elderly patients.

Hyperphosphatemia, a Cause of High Anion Gap Metabolic Acidosis: Report of a Case and Review of the Literature

Patient: Male, 74

Final Diagnosis: Metabolic acidosis due to hyperphosphatemia

Symptoms: Abdominal pain

Medication:—

Clinical Procedure: —

Specialty: Nephrology

Herbal and dietary supplements related to diarrhea and acute kidney injury: a case report

Background There is very little evidence relating to the association of herbal medicine with diarrhea and the development of acute kidney injury (AKI). This study reports a case of diarrhea-induced AKI, possibly related to an individual ingesting copious amounts of homemade mixed fruit and herb puree. Case presentation A 45-year-old Thai man with diabetes had diarrhea for 2 days, as a result of taking high amounts of a puree made up of eight mixed fruits and herbs over a 3-day period. He developed dehydration and stage 2 AKI, with a doubling of his serum creatinine. He had been receiving enalapril, as a prescribed medication, over one year. After he stopped taking both the puree and enalapril, and received fluid replacement therapy, within a week his serum creatinine had gradually decreased. The combination of puree, enalapril and AKI may also have induced hyperkalemia in this patient. Furthermore, the patient developed hyperphosphatemia due to his worsening kidney function, exacerbated by regularly taking some dietary supplements containing high levels of phosphate. His serum levels of potassium and phosphate returned to normal within a week, once the patient stopped both the puree and all dietary supplements, and had begun receiving treatment for hyperkalemia. Results The mixed fruit and herb puree taken by this man may have led to his diarrhea due to its effect; particularly if the patient was taking a high concentration of such a drink. Both the puree and enalapril are likely to attenuate the progression of kidney function. The causal relationship between the puree and AKI was probable (5 scores) assessed by the modified Naranjo algorithm. This is the first case report, as far as the authors are aware, relating the drinking of a mixed fruit and herbal puree to diarrhea and AKI in a patient with diabetes. Conclusions This case can alert health care providers to the possibility that herbal medicine could induce diarrhea and develop acute kidney injury.

Chronic kidney disease of unknown aetiology and ground-water ionicity: study based on Sri Lanka

High incidence of chronic kidney disease of unknown aetiology (CKDU) in Sri Lanka is shown to correlate with the presence of irrigation works and rivers that bring-in 'nonpoint source' fertilizer runoff from intensely agricultural regions. We review previous attempts to link CKDU with As, Cd and other standard toxins. Those studies (e.g. the WHO-sponsored study), while providing a wealth of data, are inconclusive in regard to aetiology. Here, we present new proposals based on increased ionicity of drinking water due to fertilizer runoff into the river system, redox processes in the soil and features of 'tank'-cascades and aquifers. The consequent chronic exposure to high ionicity in drinking water is proposed to debilitate the kidney via a Hofmeister-type (i.e. protein-denaturing) mechanism.

Changes in serum phosphate during treatment of diabetic ketoacidosis: predictive significance of severity of acidosis on presentation

Changes in serum phosphate during diabetic ketoacidosis (DKA) treatment are not well characterised, although it is known that serum phosphate falls with treatment. We sought to define the nature of these changes and whether the severity of acidosis on admission influenced the severity of subsequent hypophosphataemia. We retrospectively reviewed data on all patients with confirmed DKA presenting to our unit between 2007 and 2010 inclusive. Forty-three patients with 64 episodes of DKA were evaluated. At presentation, 62.5% of patient episodes were hyperphosphataemic. Initial serum phosphate in all patient episodes correlated significantly with the initial serum creatinine (r = 0.694, P < 0.01) and the initial blood glucose (r = 0.593, P < 0.01). Serum phosphate fell during the course of treatment in all episodes (mean absolute fall 1.28 ± 0.77 (SEM) mmol/L). The mean nadir phosphate was 0.58 ± 0.19 mmol/L. Ninety per cent of nadir phosphate levels were hypophosphataemic (<0.8 mmol/L), and 11% were severely hypophosphataemic (<0.32 mmol/L). Mean initial bicarbonate differed significantly between those with nadir phosphates <0.5 mmol/L (9.26 ± 4.55) and those with nadir phosphates >0.5 mmol/L (13.0 ± 4.59, P = 0.0031). Similar significant bicarbonate differences were noted between those with nadir phosphates less than and more than 0.32 mmol/L respectively (7.42 ± 2.44 and 12.2 ± 4.87, P < 0.01). The initial hyperphosphataemia is reflective of intravascular volume depletion and pre-renal renal impairment. The severity of subsequent hypophosphataemia can be predicted by the degree of metabolic acidosis on presentation. As profound hypophosphataemia can be associated with serious complications, clinicians should recognise the likelihood of this biochemical derangement in those DKA patients presenting with profound acidosis.

Hypophosphatemia-induced seizure in a child with diabetic ketoacidosis

We report an unusual case of hypophosphatemia-related seizure in a child with diabetic ketoacidosis (DKA). A 1-year-old type 1 diabetic boy with hyperglycemia, ketoacidosis, and dehydration was admitted to the pediatric intensive care unit. After having received fluid replacement using isotonic solution with added potassium and continuous intravenous insulin administration according to the protocol for DKA, the patient was conscious, awake, and fed with breast milk. After 20 hours of pediatric intensive care unit stay, he presented 2 tonic-clonic seizures followed by apnea. One hour later, he had cardiorespiratory arrest, requiring cardiovascular support and mechanical ventilation. Serum phosphorus concentration was 1.0 mg/dL, and severe hypophosphatemia was diagnosed. Subsequent to intravenous phosphate replacement, he showed improved neurological and hemodynamic statuses. No other cause of cerebral complication was found. He had no neurologic lesions and was discharged. Although hypophosphatemia is a common complication of DKA treatment, phosphate supplementation has not been routinely recommended in the treatment of DKA. Early recognition and treatment of severe hypophosphatemia in the treatment of DKA are important to reduce the risk of neurological complications.

Forensic application of ESEM and XRF-EDS techniques to a fatal case of sodium phosphate enema intoxication

Sodium phosphate enemas and laxatives are widely used for the treatment of constipation, even if a number of cases of significant toxicity due to alterations of the fluid and electrolyte equilibria (hypernatremia, hyperphosphatemia, and hypocalcemia) have been reported. We present the case of an 83-year-old man who died of fecal and chemical peritonitis secondary to an iatrogenic colon perforation (produced performing a Fleet enema through the patient's iliac colostomy) with peritoneal absorption of sodium phosphate. Environmental scanning electron microscopy coupled with an X-ray fluorescence energy dispersive spectrometry discovered multiple bright crystals formed of calcium, phosphorus, and oxygen in the brain, heart, lung, and kidney sections of the victim. The absence of these kinds of precipitates in two control samples chronically treated with Fleet enemas led us to assume that the deceased had adsorbed a great quantity of phosphorus ions from the peritoneal cavity with subsequent systemic dissemination and precipitation of calcium phosphate bindings.

Pseudohyperphosphatemia associated with high-dose liposomal amphotericin B therapy

BACKGROUND

Acute increases in serum inorganic phosphorus (Pi) up to 4.75 mmol/l in the absence of hypocalcemia and tissue deposition of calcium phosphate were noted in 3 patients receiving liposomal amphotericin B (L-AMB). We investigated L-AMB as a possible cause of pseudohyperphosphatemia.

METHODS

Serum samples from the index patient were analyzed for Pi content by our laboratory's primary analyzer (Synchron LX20) and by an alternate analyzer (Vitros). Clear and lipemic serum pools, and normal saline, were spiked with L-AMB and analyzed by the LX20 Pi method. Ultrafiltration studies were performed on patient and spiked sera.

RESULTS

Increased Pi values were obtained only from the LX20 analyzer. There was a direct linear relationship between the concentration of L-AMB in the spiked samples and the LX20 Pi results, indicating a 0.9 mmol/l Pi increase for every 100 mg/l increase in L-AMB. Ultrafiltration normalized the Pi results.

CONCLUSION

Serum Pi results may be falsely increased in patients receiving L-AMB when measured by the LX20 analyzer. This novel cause of pseudohyperphosphatemia is due to interference of L-AMB with the method and is corrected by ultrafiltration of the specimen. Since the LX20 analyzer is widely used by the clinical laboratories clinicians and laboratory personnel should recognize this interference in order to avoid unnecessary diagnostic procedures and interventions.

Serum Anion Gap: Its Uses and Limitations in Clinical Medicine

The serum anion gap, calculated from the electrolytes measured in the chemical laboratory, is defined as the sum of serum chloride and bicarbonate concentrations subtracted from the serum sodium concentration. This entity is used in the detection and analysis of acid-base disorders, assessment of quality control in the chemical laboratory, and detection of such disorders as multiple myeloma, bromide intoxication, and lithium intoxication. The normal value can vary widely, reflecting both differences in the methods that are used to measure its constituents and substantial interindividual variability. Low values most commonly indicate laboratory error or hypoalbuminemia but can denote the presence of a paraproteinemia or intoxication with lithium, bromide, or iodide. Elevated values most commonly indicate metabolic acidosis but can reflect laboratory error, metabolic alkalosis, hyperphosphatemia, or paraproteinemia. Metabolic acidosis can be divided into high anion and normal anion gap varieties, which can be present alone or concurrently. A presumed 1:1 stoichiometry between change in the serum anion gap (DeltaAG) and change in the serum bicarbonate concentration (DeltaHCO(3)(-)) has been used to uncover the concurrence of mixed metabolic acid-base disorders in patients with high anion gap acidosis. However, recent studies indicate variability in the DeltaAG/DeltaHCO(3)(-) in this disorder. This observation undercuts the ability to use this ratio alone to detect complex acid-base disorders, thus emphasizing the need to consider additional information to obtain the appropriate diagnosis. Despite these caveats, calculation of the serum anion gap remains an inexpensive and effective tool that aids detection of various acid-base disorders, hematologic malignancies, and intoxications.

Severe hyperphosphatemia and hypocalcemia following the rectal administration of a phosphate-containing Fleet pediatric enema

BACKGROUND

Toxicity secondary to rectally administered hypertonic phosphate solution in patients with normal renal function is rarely reported in the literature. We report a case of electrolyte disturbance and seizure secondary to the rectal administration of 2 Fleet pediatric enemas.

CASE REPORT

A 4-year-old white female with spinal muscular atrophy and chronic constipation was brought to the emergency department with complaints of lethargy and difficulty breathing following the administration of 2 Fleet pediatric enemas. In the emergency department, physical examination was significant for a depressed level of consciousness and shallow respirations. A basic metabolic profile was significant for a calcium of 3.3 mg/dL, phosphate of 23 mg/dL, and sodium of 153 mEq/L. Arterial blood gases revealed a pH of 7.24, Pco2 of 38 mm Hg, Po2 of 220 mm Hg. Electrocardiogram revealed a prolonged QT interval of 340 milliseconds with a corrected QT interval of 498 milliseconds. Sixteen hours postexposure, she experienced a generalized seizure unresponsive to multiple doses of lorazepam and responsive only to 100 mg of intravenous calcium chloride. Two days after presentation, the patient experienced complete resolution of symptoms.

CONCLUSION

Osmotically acting hypertonic phosphate enemas can result in severe toxicity if retained. This is true even in patients without predisposing risk factors.

Serum phosphate abnormalities in the emergency department

Abnormalities in serum phosphate levels are more prevalent in certain subsets of Emergency Department patients than in the general population. Patients with diabetic ketoacidosis, chronic obstructive pulmonary disease, alcoholism, malignancy, and renal failure are at increased risk. Multiple factors, including nutritional intake, medications, renal or intestinal excretion, and cellular redistribution, are potential etiologies. The clinical manifestations of mild hypophosphatemia or hyperphosphatemia are typically minor and nonspecific (myalgias, weakness, anorexia). When the imbalance is severe, critical complications may occur (tetany, seizures, coma, rhabdomyolysis, respiratory failure, ventricular tachycardia). Mild asymptomatic hypophosphatemia can be treated with oral phosphate supplementation (15 mg/kg daily) on an outpatient basis. Patients with severe or symptomatic hypophosphatemia should be treated with IV phosphate therapy (0.08-0.16 mg/kg over 6 h) and admitted for monitoring and subsequent serum electrolyte testing. Mild asymptomatic hyperphosphatemia is commonly managed in renal failure by limiting dietary intake and reducing absorption with phosphate-binding salts. Hemodialysis may be required for severe hyperphosphatemia with symptomatic hypocalcemia.

Acute hyperphosphatemia caused by sodium phosphate enema in a patient with liver dysfunction and chronic renal failure

We report a case of acute hyperphosphatemia secondary to rectal administration of sodium phosphate and sodium biphosphate (Fleet enema). Parathyroid hormone and calcitonin levels were measured along with phosphate clearance and the tubular reabsorption of phosphate.

Metabolic acidosis with extreme elevation of anion gap: case report and literature review

A patient with severe metabolic acidosis and an extremely elevated (57 mEq/L) serum anion gap (AG) is described, and the multiple factors that produced the patient's complex abnormalities are discussed in detail. These include renal failure, rhabdomyolysis, marked hyperphosphatemia, hemoconcentration, and an unidentified organic metabolic acidosis. A review of the literature indicates that the common thread observed in almost each instance of profoundly elevated AG values is a multifactorial pathogenesis that usually includes renal insufficiency, associated with a proven or likely cause of organic metabolic acidosis, or with exogenous phosphate intoxication.