Acid-base and electrolyte abnormalities in patients with acute leukemia

Prediction of tumor lysis syndrome in childhood acute lymphoblastic leukemia based on machine learning models: a retrospective study

Background

Tumor lysis syndrome (TLS) often occurs early after induction chemotherapy for acute lymphoblastic leukemia (ALL) and can rapidly progress. This study aimed to construct a machine learning model to predict the risk of TLS using clinical indicators at the time of ALL diagnosis.

Methods

This observational cohort study was conducted at the National Clinical Research Center for Child Health and Disease. Data were collected from pediatric ALL patients diagnosed between December 2008 and December 2021. Four machine learning models were constructed using the Least Absolute Shrinkage and Selection Operator (LASSO) to select key clinical indicators for model construction.

Results

The study included 2,243 pediatric ALL patients, and the occurrence of TLS was 8.87%. A total of 33 indicators with missing values ≤30% were collected, and 12 risk factors were selected through LASSO regression analysis. The CatBoost model with the best performance after feature screening was selected to predict the TLS of ALL patients. The CatBoost model had an AUC of 0.832 and an accuracy of 0.758. The risk factors most associated with TLS were the absence of potassium, phosphorus, aspartate transaminase (AST), white blood cell count (WBC), and urea levels.

Conclusion

We developed the first TLS prediction model for pediatric ALL to assist clinicians in risk stratification at diagnosis and in developing personalized treatment protocols. This study is registered on the China Clinical Trials Registry platform (ChiCTR2200060616).

Clinical trial registration

https://www.chictr.org.cn/, identifier ChiCTR2200060616.

Pseudohyperkalemia accompanying actual hyperphosphatemia and hypocalcemia in an adolescent with T-lymphoblastic lymphoma

Tumor lysis syndrome (TLS) is a life-threatening condition that may occur in patients with lymphoma, leukemia, or cancers with high cellular burdens. Without appropriate treatment, electrolyte imbalances, namely hyperkalemia, hyperphosphatemia, and hypocalcemia, can be fatal in patients with TLS. In pseudohyperkalemia, concurrent hyperphosphatemia and hypocalcemia can render devising a treatment strategy challenging. We report an adolescent with T-lymphoblastic lymphoma who presented with pseudohyperkalemia but actual hyperphosphatemia and hypocalcemia, to highlight the importance of accurate clinical interpretations of laboratory data in patients with TLS.

Electrolyte and acid-base disorders in cancer patients and its impact on clinical outcomes: evidence from a real-world study in China

Background: This study aims to delineate the incidence of electrolyte and acid-base disorders (EAD) in cancer patients, to figure out the risk factors of EAD, then to assess the impact of EAD on patients' in-hospital clinical outcomes.Methods: Patients with the diagnosis of malignancies hospitalized during 1 October 2014 and 30 September 2015 were recruited in Zhongshan Hospital, Fudan University in Shanghai of China. Demographic characteristics, comorbidities, and clinical data, including survival, length of stay and hospital cost, were extracted from the electronic medical record system. Electrolyte and acid-base data were acquired from the hospital laboratory database.Results: Of 25,881 cancer patients with electrolyte data, 15,000 (58.0%) cases had at least one electrolyte and acid-base abnormity. Hypocalcemia (27.8%) was the most common electrolyte disorder, followed by hypophosphatemia (26.7%), hypochloremia (24.5%) and hyponatremia (22.5%). The incidence of simple metabolic acidosis (MAC) and metabolic alkalosis (MAL) was 12.8% and 22.1% respectively. Patients with mixed metabolic acid-base disorders (MAC + MAL) accounted for 30.2%. Lower BMI score, preexisting hypertension and diabetes, renal dysfunction, receiving surgery/chemotherapy, anemia and hypoalbuminemia were screened out as the major risk factors of EAD. In-hospital mortality in patients with EAD was 2.1% as compared to those with normal electrolytes (0.3%). The risk of death significantly increased among patients with severe EAD. Similarly, the length of stay and hospital cost also tripled as the number and grade of EAD increased.Conclusion: EAD is commonly encountered in cancer patients and associated with an ominous prognosis. Patients with comorbidities, renal/liver dysfunction, and anti-tumor therapy have a higher risk of EAD. Regular monitoring of electrolytes, optimum regimen for intravenous infusion, timely correction of modifiable factors and appropriate management of EAD should not be neglected during anti-tumor treatment.

Electrolyte Disorders Induced by Antineoplastic Drugs

The use of antineoplastic drugs has a central role in treatment of patients affected by cancer but is often associated with numerous electrolyte derangements which, in many cases, could represent life-threatening conditions. In fact, while several anti-cancer agents can interfere with kidney function leading to acute kidney injury, proteinuria, and hypertension, in many cases alterations of electrolyte tubular handling and water balance occur. This review summarizes the mechanisms underlying the disturbances of sodium, potassium, magnesium, calcium, and phosphate metabolism during anti-cancer treatment. Platinum compounds are associated with sodium, potassium, and magnesium derangements while alkylating agents and Vinca alkaloids with hyponatremia due to syndrome of inappropriate antidiuretic hormone secretion (SIADH). Novel anti-neoplastic agents, such as targeted therapies (monoclonal antibodies, tyrosine kinase inhibitors, immunomodulators, mammalian target of rapamycin), can induce SIADH-related hyponatremia and, less frequently, urinary sodium loss. The blockade of epidermal growth factor receptor (EGFR) by anti-EGFR antibodies can result in clinically significant magnesium and potassium losses. Finally, the tumor lysis syndrome is associated with hyperphosphatemia, hypocalcemia and hyperkalemia, all of which represent serious complications of chemotherapy. Thus, clinicians should be aware of these side effects of antineoplastic drugs, in order to set out preventive measures and start appropriate treatments.

Hypocalcemia in cancer patients: An exploratory study

Introduction

Calcium has several physiological functions and when it registers abnormal serum levels those functions may be impacted with potentially severe consequences. There is much research on hypercalcemia in cancer patients, but there are no recent studies on the prevalence of hypocalcemia in those patients. However, there has been an evolution in oncology, namely, new drugs that may directly or indirectly result in hypocalcemia. The primary aim was to explore the association of hypocalcemia with the diverse types of cancer. The secondary aim was to study the influence that hypocalcemia might have on survival.

Methods

Review of the records of patients ≥18 years old, with total calcium <2.0 mmol/L measured in 2013 in a cancer center.

Results

Eight hundred twenty-nine patients were included. Four hundred thirty-nine (53%) were male. The median age was 63 years. The most frequent cancer diagnoses were hematological 196 (24%) and colorectal 111 (13%). Six hundred thirty-eight patients had measured serum albumin, with a median of 25.5 g/L (14-47). When corrected for albumin level, calcium was in the normal range in 210 (33%) cases. The median survival of patients with corrected calcium lower than normal was 479 days (95% confidence interval [CI]: 309-649) and that of patients with normal corrected calcium was 62 days (95% CI: 33-91), P < .001. In a multivariate analysis, age, primary cancer, and albumin were significantly associated with survival.

Conclusion

Hypocalcemia is associated with several types of cancer. A low calcium level is not by itself a factor of a poor prognosis since other factors seem to be more important.

Bone resorption: supporting immunometabolism

Activation of the immune system is associated with an increase in the breakdown of various peripheral tissues, including bone. Despite the widely appreciated role of inflammatory mediators in promoting bone resorption, the functional value behind this process is not completely understood. Recent advances in the field of immunometabolism have highlighted the metabolic reprogramming that takes place in activated immune cells. It is now believed that the breakdown of peripheral tissue provides metabolic substrates to fuel metabolic anabolism in activated immune cells. We argue that phosphate, liberated by bone resorption, plays an indispensable role in sustaining immune cell metabolism. The liberated phosphate is then incorporated into macromolecules such as nucleotides and phospholipids, and is also used for the phosphorylation of metabolites (e.g. glycolytic intermediates). In addition, magnesium, also liberated during the breakdown of bone, is an essential cofactor required by various metabolic enzymes which are upregulated in activated immune cells. Finally, calcium activates various additional molecules involved in immune cell migration. Taken together, these factors suggest a key role for bone resorption during infection.

Correlation of Calcium and Magnesium Levels in the Biological Samples of Different Types of Acute Leukemia Children

Acute leukemia (AL) is a common childhood malignancy. It is clinically and morphologically heterogeneous. The present work was intended to estimate the concentration of calcium (Ca) and magnesium (Mg) in serum and whole blood samples of children having AL; 1- to 5- and 6- to 10-year-old children age group was chosen of both genders. Healthy children of the same age group were selected as controls for comparative study. For sample pretreatment, a microwave-assisted acid digestion (MAD) was carried out, to assess the concentration of Ca and Mg in biological samples of AL children. The MAD method was validated by analyzing Clinchek® Control certified samples of whole blood and serum. Ca and Mg were analyzed in the digested samples by flame atomic absorption spectrometry (FAAS). The results showed significantly higher concentration of Ca, whereas lower contents of Mg in the serum and whole blood of AL children in both genders, as compared to healthy subjects. The data provide assistance to physician/clinicians and other professional staffs to investigate the imbalance of minerals in biological samples of AL children.

Hypophosphatemia in the setting of metabolic bone disease: case reports and diagnostic algorithm

Osteoporosis is the most commonly encountered metabolic bone disease, and metabolic bone-disease clinics have been established to assist in the diagnosis and treatment of uncommon causes of low bone-mineral density. Hypophosphatemia leading to metabolic bone disease may be encountered, and an understanding of phosphate homeostasis can aid in the diagnosis. Two cases of hypophosphatemia leading to low bone-mineral densities were seen at the University of Alabama at Birmingham Osteoporosis Clinic. We developed a diagnostic algorithm, and the laboratory values of each patient were tested with the algorithm. The algorithm, incorporating the use of a spot urine phosphate and spot urine creatinine level at the time of initial serum metabolic profile evaluation, accurately determined the cause of hypophosphatemia in each case.

Acute Lymphoblastic Leukemia Presenting as Fanconi Syndrome

Acute lymphoblastic leukemia (ALL) presenting as Fanconi syndrome (FS) is extremely rare. Here, we report a case of ALL presenting as bilateral nephromegaly following FS. A 2-year-old girl was unexpectedly diagnosed with bilateral nephromegaly. After 2 weeks, she developed general fatigue, thirst, and polyuria. Laboratory examinations revealed renal tubular acidosis, hypokalemia, hypophosphatemia, and aminoaciduria, and FS was diagnosed. Replacement of bicarbonate and potassium did not improve her condition. Two weeks after the onset of FS, leukemic cells appeared on a peripheral blood smear, and the patient was diagnosed with precursor B-cell ALL presenting as nephromegaly and FS. Chemotherapy brought about a prompt resolution of acidosis and electrolyte abnormalities, without renal dysfunction. The patient remains well 4 years after the onset of the disease. Although extremely rare, FS should be recognized as one of the emerging renal complications of ALL.

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.

Health effects of desalinated water: Role of electrolyte disturbance in cancer development

This review contends that "healthy" water in terms of electrolyte balance is as important as "pure" water in promoting public health. It considers the growing use of desalination (demineralization) technologies in drinking water treatment which often results in tap water with very low concentrations of sodium, potassium, magnesium and calcium. Ingestion of such water can lead to electrolyte abnormalities marked by hyponatremia, hypokalemia, hypomagnesemia and hypocalcemia which are among the most common and recognizable features in cancer patients. The causal relationships between exposure to demineralized water and malignancies are poorly understood. This review highlights some of the epidemiological and in vivo evidence that link dysregulated electrolyte metabolism with carcinogenesis and the development of cancer hallmarks. It discusses how ingestion of demineralized water can have a procarcinogenic effect through mediating some of the critical pathways and processes in the cancer microenvironment such as angiogenesis, genomic instability, resistance to programmed cell death, sustained proliferative signaling, cell immortalization and tumorigenic inflammation. Evidence that hypoosmotic stress-response processes can upregulate a number of potential oncogenes is well supported by a number studies. In view of the rising production and consumption of demineralized water in most parts of the world, there is a strong need for further research on the biological importance and protean roles of electrolyte abnormalities in promoting, antagonizing or otherwise enabling the development of cancer. The countries of the Gulf Cooperative Council (GCC) where most people consume desalinated water would be a logical place to start this research.

Electrolyte disorders associated with cancer

Patients with malignancies commonly experience abnormalities in serum electrolytes, including hyponatremia, hypokalemia, hyperkalemia, hypophosphatemia, and hypercalcemia. In many cases, the causes of these electolyte disturbances are due to common etiologies not unique to the underlying cancer. However, at other times, these electrolyte disorders signal the presence of paraneoplastic processes and portend a poor prognosis. Furthermore, the development of these electrolyte abnormalities may be associated with symptoms that can negatively affect quality of life and may prevent certain chemotherapeutic regimens. Thus, prompt recognition of these disorders and corrective therapy is critical in the care of the patient with cancer.

Kidney involvement in leukemia and lymphoma

Leukemia and lymphoma are hematologic malignancies that can affect any age group. Disease can be aggressive or indolent, often with multiorgan system involvement. Kidney involvement in leukemia and lymphoma can be quite extensive. Acute kidney injury (AKI) is quite prevalent in these patients, with prerenal and acute tubular necrosis being the most common etiologies. However other prerenal, intrinsic, and obstructive etiologies are possible. AKI can be a direct effect of the malignancy, a complication of the malignancy, or the consequence or side effect of chemotherapy. Nephrotic syndrome and glomerulonephritis, often presenting without overt kidney failure, have also been seen in all forms of leukemia and lymphoma. Lastly, the direct effects of the malignancy and complications from the tumor often result in numerous electrolyte disturbances and acid-base disorders, with life-threatening consequences if left untreated.

Adrenal crisis in a patient with acute myeloid leukaemia

Adrenal crisis is a group of clinical manifestation predominantly with hypotensive shock, electrolyte imbalance in a patient with adrenal insufficiency or in a patient who was abruptly withdrawn from glucocorticoid treatment acute myeloid leukaemia (AML) is one of the most common acute leukaemia in adults. Though the above diseases are commonly seen in individual patients, the coexistence of both conditions in the same patient is rare. We reported a 64-year-old African-American man with a history of bilateral deep vein thrombosis, who presented initially with fatigue, neutropenia and macrocytic anaemia. The patient developed a small bowel obstruction during his first hospital course, which resolved spontaneously with conservative management after an exploratory laparotomy. While waiting for his bone marrow biopsy, the patient developed hypotension, hyponatraemia and hyperkalaemia for which adrenal crisis was suspected. Later on, laboratory studies confirmed the diagnosis of primary adrenal insufficiency and the bone marrow was conclusive for AML.

Iatrogenic hyponatremia in hospitalized children: Can it be avoided?

Iatrogenic hyponatremia in hospitalized children is a common problem. It is usually caused by the administration of free water, either orally or through the prescription of hypotonic intravenous fluids. It can result in cerebral edema and death, and is most commonly reported in healthy children undergoing minor surgery. The current teachings and practical guidelines for maintenance fluid infusions are based on caloric expenditure data in healthy children that were derived and published more than 50 years ago. A re-evaluation of these data and more recent recognition that hospitalized children are vulnerable to hyponatremia, with its resulting morbidity and mortality rates, suggest that changes in paediatricians' approach to fluid administration are necessary. There is no single fluid therapy that is optimal for all hospitalized children. A thorough assessment of the type of fluid, volume of fluid and electrolyte requirements based on individual patient requirements, plus rigorous monitoring, is required in any child receiving intravenous fluids. The present article reviews how hyponatremia occurs and makes recommendations for minimizing the risk of iatrogenic hyponatremia.

Phase I/II multicenter study to assess the safety, tolerability, pharmacokinetics and pharmacodynamics of AZD4877 in patients with refractory acute myeloid leukemia

Eg5 (kinesin spindle protein) is a microtubule motor protein, essential for centrosome separation during mitosis. This Phase I/II, open-label, multicenter, two-part study investigated AZD4877, a potent Eg5 inhibitor, in patients with acute myeloid leukemia. Primary objectives were to determine the maximum tolerated dose (MTD) (part A), assess efficacy (part B) and determine the pharmacokinetic profile (parts A and B). Secondary objectives included assessment of safety and tolerability. AZD4877 was administered at a range of doses (2, 4, 7, 10, 13, 16 and 18 mg/day) as a 1-hour intravenous infusion on three consecutive days of a continuous 2-week schedule. The MTD in part A was defined as 16 mg/day based on dose-limiting stomatitis at 16 and 18 mg/day, hyperbilirubinemia at 16 mg/day and palmar-plantar erythrodysesthesia syndrome at 18 mg/day. Systemic exposure to AZD4877 generally increased with increasing dose whereas half-life was not dose dependent. No evaluable patients experienced a complete remission (CR) or CR with incomplete blood count recovery (CRi), demonstrating no evidence of AZD4877 efficacy in this population. Evidence of monoasters in all but the 4 mg/day dose group provided proof of mechanism for AZD4877. This study was terminated due to lack of efficacy. (ClinicalTrials.gov identifier NCT00486265).

Electrolyte disturbances and acute kidney injury in patients with cancer

The interrelation between kidney disease and cancer is complex and reciprocal. Among the most frequent cancer-associated kidney diseases are the electrolyte and acid-base disturbances, which occur frequently and often are associated with an ominous prognosis, and acute kidney injury. Tumor lysis syndrome is a potentially life-threatening condition that frequently occurs in patients with a high tumor burden and high cellular turnover after cytotoxic therapy (including steroids in steroid-sensitive hematologic malignancies). Electrolyte and acid-base disturbances are the consequence of neoplastic spread, anticancer treatment, or, more rarely, paraneoplastic phenomena of all types of tumors. This article reviews hyponatremia and hypernatremia, hypokalemia and hyperkalemia, hypomagnesemia, hypercalcemia and hypocalcemia, hypophosphatemia, and the most important disturbances in acid-base balance in cancer patients. Acute kidney injury (AKI) is a frequent occurrence in cancer patients and has the potential to substantially alter the outcome of patients with cancer and jeopardize their chances of receiving optimal cancer treatment and a potential cure. As in many other circumstances, the etiology of AKI in cancer patients is multifactorial. Initiation and/or continuation of dialysis in the AKI cancer patient should be based on the general clinical condition and overall life expectancy and the personal patient expectations on quality of life after eventual recovery.

Causes and mechanisms of acid-base and electrolyte abnormalities in cancer patients

Patients with cancer frequently exhibit acid-base and electrolyte disturbances that complicate their management and prolong their hospitalization. The mechanisms encountered for these abnormalities are multifactorial in origin. Both the underlying disease and the therapeutic interventions can contribute to the development of these disturbances. An understanding of the mechanisms involved in their pathogenesis is of paramount importance for their prevention and treatment in cancer patients. This article briefly reviews the causes and the pathophysiology of acid-base and electrolyte abnormalities observed in cancer patients.

Hypophosphatemia: an evidence-based approach to its clinical consequences and management

Optimal cellular function is dependent on maintenance of a normal serum phosphorus concentration. Serum phosphorus concentration is affected by several determinants, the most important of which is regulation of phosphorus reabsorption by the kidney. The majority of this reabsorption (80%) occurs in the proximal tubule and is mediated by an isoform of the sodium-phosphate cotransporter (NaPi-II). Parathyroid hormone, via a variety of intracellular signaling cascades leading to NaPi-IIa internalization and downregulation, is the main regulator of renal phosphate reabsorption. Shift of phosphorus from extracellular to intracellular compartments, decreased gastrointestinal absorption, and increased urinary losses, are the primary mechanisms of hypophosphatemia, which affects approximately 2% of hospitalized patients. Hypophosphatemia has been implicated as a cause of rhabdomyolysis, respiratory failure, hemolysis and left ventricular dysfunction. With the exception of ventilated patients, there is little evidence that moderate hypophosphatemia has significant clinical consequences in humans, and aggressive intravenous phosphate replacement is unnecessary. By contrast, patients with severe hypophosphatemia should be treated. Intravenous repletion may be considered, especially for patients who have clinical sequelae of hypophosphatemia.

Alterations in electrolyte equilibrium in patients with acute leukemia

BACKGROUND AND AIM

A wide array of disturbances in electrolyte equilibrium is commonly seen in patients with acute leukemia (AL). These abnormalities present a potential hazard in these patients, as that of enhancing the cardiotoxic effects of certain chemotherapeutic regimens. The literature dealing with AL-related electrolyte abnormalities and their interactions in leukemic patients was reviewed.

DATA SYNTHESIS

Sources included MEDLINE and EMBASE. The search strategy was based on the combination of 'acute leukemia', 'electrolyte abnormalities', 'acid-base disorders', 'potassium', 'sodium', 'magnesium', 'calcium', and 'phosphorus'. References of retrieved articles were also screened. A decrease in serum potassium, mainly owing to lysozyme-induced tubular damage, appears to be one of the most frequent and potentially hazardous abnormalities. Other clinically significant metabolic perturbations include hyponatremia and hypercalcemia.

CONCLUSION

A broad spectrum of electrolyte abnormalities is encountered in the clinical setting of AL, which are related to the disease process per se and/or to the therapeutic interventions. Clinicians should be vigilant for early detection and appropriate management of these disorders before the initiation of chemotherapy regimens as well as during treatment.

Drug-induced hypomagnesaemia : scope and management

Nearly 50 medications have been implicated as inducing hypomagnesaemia, sometimes based on insufficient data regarding clinical significance and frequency of occurrence. In fact, clinical effects attributed to hypomagnaesemia have been reported in only 17 of these drugs. A considerable amount of literature relating to individual drugs has been published, yet a comprehensive overview of this issue is not available and the hypomagnesaemic effect of a drug could be either overemphasised or under-rated. In addition, there are neither guidelines regarding treatment, prevention and monitoring of drug-induced hypomagnesaemia nor agreement as to what serum level of magnesium may actually be defined as 'hypomagnesaemia'. By compiling data from published papers, electronic databases, textbooks and product information leaflets, we attempted to assess the clinical significance of hypomagnesaemia induced by each drug. A practical approach for managing drug-induced hypomagnesaemia, incorporating both published literature and personal experience of the physician, is proposed. When drugs classified as inducing 'significant' hypomagnesaemia (cisplatin, amphotericin B, ciclosporin) are administered, routine magnesium monitoring is warranted, preventive treatment should be considered and treatment of hypomagnesaemia should be initiated with or without overt clinical manifestations. In drugs belonging to the 'potentially significant' category, among which are amikacin, gentamicin, laxatives, pentamidine, tobramycin, tacrolimus and carboplatin, magnesium monitoring is justified when either of the following occurs: clinical manifestations are apparent; persistent hypokalaemia, hypocalcaemia or alkalosis are present; other precipitating factors for hypomagnesaemia coexist; or treatment is with more than one potentially hypomagnesaemic drug. No preventive treatment is required and treatment should be initiated only if hypomagnesaemia is accompanied by symptoms or clinically significant relevant laboratory findings. In those drugs whose hypomagnesaemic effect is labelled as 'questionable', including furosemide and hydrochlorothiazide, routine monitoring and treatment are not required.

Electrolyte abnormalities at diagnosis of acute lymphocytic leukemia may be a clue for renal damage in long-term period

The objective of this study was to determine the frequency of electrolyte perturbations and their relationship with leukemic status before and after chemotherapy in patients with acute lymphocytic leukemia. Blood biochemistry, liver and renal function tests, and renal sonograms were examined at diagnosis and during induction therapy in 334 patients. Renal and electrolyte disturbances were then studied in 116 patients between 3 and 110 months after cessation of the St. Jude chemotherapy treatment protocol. Glomerular filtration rate, electrolyte, protein, and beta-2-microglobulin levels were determined in fresh urine samples, and serum electrolyte levels were examined in blood samples. Renal sonographic examinations and scintigraphic examinations were performed with DMSA and MAG-3. Renal leukemic involvement was detected by sonographic examination in 32 patients who had also presented with hyperphosphatemia or hyperuricemia. Patients with electrolyte disorders at diagnosis were less likely to have tumor lysis syndrome during induction chemotherapy. This may be explained by correction of their electrolyte disorders at the time of diagnosis, which may protect them from tumor lysis syndrome. Hypocalcemia and hyponatremia at the time of diagnosis were found to be significant initial risk factors for renal scan abnormalities and microproteinuria, respectively, during the late therapy period (P < 0.05). Electrolyte abnormalities and renal changes were commonly observed before and after therapy for leukemia. Patients presenting with hypocalcemia and hyponatremia should be examined for microproteinuria and should undergo renal scanning during the late therapy period.

Acute hyponatremia related to intravenous fluid administration in hospitalized children: an observational study

OBJECTIVE

To develop hyponatremia (plasma sodium concentration [P(Na)] <136 mmol/L), one needs a source of water input and antidiuretic hormone secretion release to diminish its excretion. The administration of hypotonic maintenance fluids is common practice in hospitalized children. The objective of this study was to identify risk factors for the development of hospital-acquired, acute hyponatremia in a tertiary care hospital using a retrospective analysis.

METHODS

All children who presented to the emergency department in a 3-month period and had at least 1 P(Na) measured (n = 1586) were evaluated. Those who were admitted were followed for the next 48 hours to identify patients with hospital-acquired hyponatremia. An age- and gender-matched case-control (1:3) analysis was performed with patients who did not become hyponatremic.

RESULTS

Hyponatremia (P(Na) <136 mmol/L) was documented in 131 of 1586 patients with > or = 1 P(Na) measurements. Although 96 patients were hyponatremic on presentation, our study group consisted of 40 patients who developed hyponatremia in hospital. The case-control study showed that the patients in the hospital-acquired hyponatremia group received significantly more EFW and had a higher positive water balance. With respect to outcomes, 2 patients had major neurologic sequelae and 1 died.

CONCLUSION

The most important factor for hospital-acquired hyponatremia is the administration of hypotonic fluid. We suggest that hypotonic fluid not be given to children when they have a P(Na) <138 mmol/L.

Acute lymphoblastic leukemia presenting with lactic acidosis and renal tubular dysfunction

Acute lymphoblastic leukemia (ALL) in children can rarely present with severe lactic acidosis in the absence of a high white blood cell count or other complications. Renal tubular dysfunction with hypercalciuria and hypocalcemia in the absence of pre-existing renal disease or concurrent medications has not been described at presentation in childhood ALL. The authors describe a 7-year-old boy with ALL presenting with severe lactic acidosis and renal tubular dysfunction, both of which were refractory to conventional management and resolved rapidly with appropriate chemotherapy.

Hypouricemia in individuals admitted to an inpatient hospital-based facility

BACKGROUND

Decreased serum uric acid levels resulting from renal urate wasting occasionally are reported in hospitalized patients because of isolated or generalized proximal tubular damage. There are limited recent findings with regard to the incidence and cause of hypouricemia in patients admitted to an internal medicine clinic. The aim of this study is to examine the prevalence of hypouricemia in individuals admitted to our inpatient hospital-based facility and identify underlying causes and pathogenetic mechanisms and any association of hypouricemia and uricosuria with other tubular defects.

METHODS

A total of 7,250 serum urate measurements were available on patients' admission. Hypouricemia is defined as a serum urate level less than 2.5 mg/dL (149 micromo/L). In all hypouricemic cases, a detailed clinical and laboratory investigation was performed.

RESULTS

Hypouricemia was found in 90 patients (1.24%). In all except one patient, hypouricemia was associated with inappropriate uricosuria (urate fractional excretion [FE] > 10%; range, 10.8% to 94%). There was an inverse correlation between serum uric acid level and its FE (r = -0.73; P < 0.0001). The most common causes of hypouricemia were obstructive jaundice of any cause (n = 18), solid or hematologic neoplasias (n = 17), diabetes mellitus (n = 12), drugs affecting urate homeostasis (n = 10), and intracranial diseases (n = 8). Seventeen patients with hypouricemia showed one or more other manifestations of proximal tubular damage, such as glucosuria, inappropriate phosphaturia leading to hypophosphatemia, and kaliuria resulting in hypokalemia.

CONCLUSION

Hypouricemia caused by inappropriate uricosuria is not rare in patients admitted to an internal medicine clinic, is related to underlying diseases, and may be associated with other abnormalities of proximal tubular function.

Validity of hospital discharge International Classification of Diseases (ICD) codes for identifying patients with hyponatremia

Medical diagnosis can be studied using various sources of information, such as medical and hospital discharge records and laboratory measurements. These sources do not always concur. The objective of the present study was to assess the sensitivity, specificity, and positive and negative predictive values of hospital discharge diagnosis compared with clinical laboratory data for the identification of hyponatremia. Patients with hyponatremia were selected from a hospital information system determined by the International Classification of Diseases, 9th edition (ICD-9). The validity parameters for hyponatremia (ICD code 276.1) were estimated by comparison with accurate serum sodium (Na+) levels. A total of 2632 cases of hyponatremia were identified using laboratory measurements (Na+ < or =135 mmol/L). The sensitivity of ICD coding for hyponatremia was maximally about 30% for patients with very severe hyponatremia (Na+ < or =115 mmol/L). Corresponding specificities were high (>99%). In 87% of the cases with severe hyponatremia (Na+ < or =125 mmol/L), other discharge ICD codes reflecting severe morbidity were found. This study suggests that ICD codes for hyponatremia represent only one third of the patients admitted to the hospital and experiencing hyponatremia. About two thirds of the patients with hyponatremia were classified as hospitalized for other reasons. To assess the validity of case finding of patients with hyponatremia, the use of analytical techniques, such as certain laboratory measurements, is advisable.

High prevelance of chronic magnesium deficiency in T cell lymphoblastic leukemia and chronic zinc deficiency in children with acute lymphoblastic leukemia and malignant lymphoma

Magnesium and zinc are the elements having essential roles in regulation of cell growth, division and differentiation. There have been some studies in the literature suggesting an association between the deficiency of these elements and the development of malignant disorders. In this study hair and serum zinc and magnesium levels were investigated in children with acute lymphoblastic leukemia (ALL) and malignant lymphoma (ML) at the time of initial diagnosis. Ten children with T-cell ALL, 10 children with B-precursor ALL, 5 children with Burkitt's Lymphoma (BL), 11 children with Hodgkin's lymphoma (HL), 10 children with non-Burkitt non-Hodgkin's lymphoma (NBNHL) and 12 age and sex matched healthy children as a control group were included in the study. Mean hair magnesium levels in all of the groups of the patients were lower than the levels in the control group but the difference was statistically significant only in the children with T cell ALL comparable to the controls (28.9+/-3.9 microg/g and 87.6+/-18.5 microg/g respectiveley, p<0,05). Mean serum magnesium levels in all the cohorts were not significantly different than those in controls (p>0.05 in each comparison). Mean hair zinc levels in the patients with T-cell, B-precursor ALL, BL, HL, NBNHL were 103.4+/-14.6 microg/g, 100.9+/-7.8 microg/g, 91.1+/-19 microg/g, 72.5+/-9.1 microg/g, 103.2+/-12.2 microg/g respectively. Each of these levels were significantly lower than the mean hair zinc levels of the control group (141.2+/-9.6 microg/g, p<0.05 in each comparison). Although mean serum zinc levels in all of the groups were also decreased, the differences were statistically significant only in the groups with B-precursor ALL, HL and NBNHL (75.9+/-5.29 microg/dl, 68.6+/-7.3 microg/dl, 85.7+/-5.5 microg/dl respectively) when compared with controls (105.1+/-9.9 microg/dl, p<0.05 in each comparison). Hair magnesium and zinc levels showed a positive correlation with each other in all the groups (r congruent with 0.5). No significant difference was found in the mean hair/serum magnesium and zinc levels between malnourished and nonmalnourished patients. In conclusion, regarding the results of our study and previous data in the literature chronic magnesium and zinc deficiency seems to be associated with the development of ALL and malignant lymphoma in a group of patients.