Hypercalcemia in the Intensive Care Unit: A Review of Pathophysiology, Diagnosis, and Modern Therapy

Assessment of drug-induced electrolyte disorders in intensive care units: a multicenter observational study

Objective

Electrolyte disorder (ED) is frequently encountered critically ill patients during admission or admission to the intensive care unit (ICU). This study aimed to determine the frequency of ED encountered in ICU patients to evaluate the relationship of ED with drugs.

Methods

This prospective, multicenter study was conducted in the medical and anesthesiology ICUs of two training and research hospitals and included patients with at least one ED during admission or hospitalization in the ICUs. The relationship between ED and the drug was evaluated by calculating the logistic probabilistic method scale (LPMS) and the expert panel's evaluation. The correlation between EDs and LPMS was determined using Kendal tau. A binary logistic regression model was preferred in the analysis of factors related to ED. Statistical significance was set as p < 0.05.

Results

A total of 117 patients were included in the study. A total of 165 EDs were detected, including at least one in 88 (75.2%) patients. According to the expert panel, 61 (21.7%) of EDs were drug-related, whereas according to the LPMS, 111 (39.6%) (p < 0.001). Mortality (50% vs. 13.7%) and mechanical ventilation rates (52.2% vs. 17.2%) were significantly higher in patients with ED (p < 0.001). Patients with ED had 8.352 times higher odds of exhibiting mortality (OR: 8.352, %95 CI: 1.598-43.648, p: 0.012) and need mechanical ventilation with higher odds of 3.229 (OR: 3.229 95% CI: 0.815-12.787 p: 0.045). Patient who required enteral or parenteral feeding were associated with an increased likelihood of exhibiting ED (respectively OR: 30.057, %95 CI: 2.265-398.892, p: 0.01, OR: 5.537, %95 CI: 1.406-21.800, p: 0.014).

Conclusion

EDs are very common in the ICU. Dysnatremia was detected more commonly in other EDs. It has also been found that patients with ED are more often under mechanical ventilation, have more prolonged hospitalizations, and have higher mortality rates than patients without ED. The suitability of LPMS for assessing ED-drug relationships in the ICU context is questioned.

A 52-Year-Old Woman with Weakness and Confusion

A 52-Year-Old Woman with Weakness and ConfusionA 52-year-old woman presented for evaluation of abdominal pain, weakness, and confusion. How do you approach the evaluation, and what is the diagnosis?

Research progress of biomineralization for the diagnosis and treatment of malignant tumors

Malignant tumors have long been a prominent subject of research in order to foster innovation and advancement in diagnostic and therapeutic modalities. However, the current clinical treatment of malignant tumors faces significant limitations. In light of recent advancements, the World Health Organization (WHO) officially designated malignant tumors as a chronic disease in 2006. Accordingly, maintaining the tumor in a stable state and minimizing its detrimental impact on the body emerges as a potentially advantageous approach to oncological treatment. One emerging strategy that has garnered substantial attention from the academic community is the construction of a biomineralized layer surrounding solid tumors for tumor blockade therapy. This innovative approach is regarded as safe, effective, and long-lasting. This review aims to provide a comprehensive summary of the advancements made in the utilization of biomineralization for the diagnosis and treatment of malignant tumors.

Disorders of Calcium and Magnesium

This review will discuss the importance and homeostasis of calcium and magnesium in the human body, as well as the implications and treatment of disordered calcium and magnesium. With calcium and magnesium often considered to be the "forgotten cations" in medicine, it is our hope that this review will lead providers to evaluate for and effectively manage these electrolyte disorders in the emergency department.

Clinical Toxicology of Vitamin D in Pediatrics: A Review and Case Reports

Intoxication of vitamin D is not a common case in pediatrics. Vitamin D supplements are sold as OTC drugs; however, there is a lack of public education about the permissible limits of vitamin D intake which may lead to vitamin D toxicity (VDT). This review aims to give insights to readers or practitioners about the clinical toxicology of vitamin D in pediatrics, which includes the mechanism of VDT, case reports, and the management of vitamin D poisoning. VDT refers to serum 25(OH)D levels, particularly when the level exceeds 100 ng/mL (250 nmol/L) or is defined as hypervitaminosis D. Hypercalcemia is a common condition of vitamin D toxicity. Vitamin D and its metabolites in moderate levels can induce hypercalcemia, as indicated by the elevation of osteoclastic bone resorption, the presence of calcium in renal tubules, intestinal calcium intake (through increased production of calcium-binding protein in enterocytes), and the decrease of parathyroid hormone synthesis. VDT in pediatrics can be managed by discontinuing vitamin D intake; using activated charcoal, furosemide, prednisone, and calcitonin; rehydration using intravenous sodium chloride 0.9%; and dextrose fluid therapy. It is important for parents to be more careful when providing vitamin D to their children.

State-of-the-Art Evaluation of Acute Adult Disorders of Consciousness for the General Intensivist

OBJECTIVES

To provide a concise review of knowledge and practice pertaining to the diagnosis and initial management of unanticipated adult patient disorders of consciousness (DoC) by the general intensivist.

DATA SOURCES

Detailed search strategy using PubMed and OVID Medline for English language articles describing adult patient acute DoC diagnostic evaluation and initial management strategies including indications for transfer.

STUDY SELECTION

Descriptive and interventional studies that address acute adult DoC, their evaluation and initial management, indications for transfer, as well as outcome prognostication.

DATA EXTRACTION

Relevant descriptions or studies were reviewed, and the following aspects of each manuscript were identified, abstracted, and analyzed: setting, study population, aims, methods, results, and relevant implications for adult critical care practice.

DATA SYNTHESIS

Acute adult DoC may be categorized by etiology including structural, functional, infectious, inflammatory, and pharmacologic, the understanding of which drives diagnostic investigation, monitoring, acute therapy, and subsequent specialist care decisions including team-based local care as well as intra- and inter-facility transfer.

CONCLUSIONS

Acute adult DoC may be initially comprehensively addressed by the general intensivist using an etiology-driven and team-based approach. Certain clinical conditions, procedural expertise needs, or resource limitations inform transfer decision-making within a complex care facility or to one with greater complexity. Emerging collaborative science helps improve our current knowledge of acute DoC to better align therapies with underpinning etiologies.

A Systematic Review Supporting the Endocrine Society Clinical Practice Guideline on the Treatment of Hypercalcemia of Malignancy in Adults

CONTEXT

Hypercalcemia is a common complication of malignancy that is associated with high morbidity and mortality.

OBJECTIVE

To support development of the Endocrine Society Clinical Practice Guideline for the treatment of hypercalcemia of malignancy in adults.

METHODS

We searched multiple databases for studies that addressed 8 clinical questions prioritized by a guideline panel from the Endocrine Society. Quantitative and qualitative synthesis was performed. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess certainty of evidence.

RESULTS

We reviewed 1949 citations, from which we included 21 studies. The risk of bias for most of the included studies was moderate. A higher proportion of patients who received bisphosphonate achieved resolution of hypercalcemia when compared to placebo. The incidence rate of adverse events was significantly higher in the bisphosphonate group. Comparing denosumab to bisphosphonate, there was no significant difference in the rate of patients who achieved resolution of hypercalcemia. Two-thirds of patients with refractory/recurrent hypercalcemia of malignancy who received denosumab following bisphosphonate therapy achieved resolution of hypercalcemia. Addition of calcitonin to bisphosphonate therapy did not affect the resolution of hypercalcemia, time to normocalcemia, or hypocalcemia. Only indirect evidence was available to address questions on the management of hypercalcemia in tumors associated with high calcitriol levels, refractory/recurrent hypercalcemia of malignancy following the use of bisphosphonates, and the use of calcimimetics in the treatment of hypercalcemia associated with parathyroid carcinoma. The certainty of the evidence to address all 8 clinical questions was low to very low.

CONCLUSION

The evidence summarized in this systematic review addresses the benefits and harms of treatments of hypercalcemia of malignancy. Additional information about patients' values and preferences, and other important decisional and contextual factors is needed to facilitate the development of clinical recommendations.

Treatment of Hypercalcemia of Malignancy in Adults: An Endocrine Society Clinical Practice Guideline

BACKGROUND

Hypercalcemia of malignancy (HCM) is the most common metabolic complication of malignancies, but its incidence may be declining due to potent chemotherapeutic agents. The high mortality associated with HCM has declined markedly due to the introduction of increasingly effective chemotherapeutic drugs. Despite the widespread availability of efficacious medications to treat HCM, evidence-based recommendations to manage this debilitating condition are lacking.

OBJECTIVE

To develop guidelines for the treatment of adults with HCM.

METHODS

A multidisciplinary panel of clinical experts, together with experts in systematic literature review, identified and prioritized 8 clinical questions related to the treatment of HCM in adult patients. The systematic reviews (SRs) queried electronic databases for studies relevant to the selected questions. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology was used to assess the certainty of evidence and make recommendations. An independent SR was conducted in parallel to assess patients' and physicians' values and preferences, costs, resources needed, acceptability, feasibility, equity, and other domains relevant to the Evidence-to-Decision framework as well as to enable judgements and recommendations.

RESULTS

The panel recommends (strong recommendation) in adults with HCM treatment with denosumab (Dmab) or an intravenous (IV) bisphosphonate (BP). The following recommendations were based on low certainty of the evidence. The panel suggests (conditional recommendation) (1) in adults with HCM, the use of Dmab rather than an IV BP; (2) in adults with severe HCM, a combination of calcitonin and an IV BP or Dmab therapy as initial treatment; and (3) in adults with refractory/recurrent HCM despite treatment with BP, the use of Dmab. The panel suggests (conditional recommendation) the addition of an IV BP or Dmab in adult patients with hypercalcemia due to tumors associated with high calcitriol levels who are already receiving glucocorticoid therapy but continue to have severe or symptomatic HCM. The panel suggests (conditional recommendation) in adult patients with hypercalcemia due to parathyroid carcinoma, treatment with either a calcimimetic or an antiresorptive (IV BP or Dmab). The panel judges the treatments as probably accessible and feasible for most recommendations but noted variability in costs, resources required, and their impact on equity.

CONCLUSIONS

The panel's recommendations are based on currently available evidence considering the most important outcomes in HCM to patients and key stakeholders. Treatment of the primary malignancy is instrumental for controlling hypercalcemia and preventing its recurrence. The recommendations provide a framework for the medical management of adults with HCM and incorporate important decisional and contextual factors. The guidelines underscore current knowledge gaps that can be used to establish future research agendas.

Negative calcium balance despite normal plasma ionized calcium concentrations during citrate anticoagulated continuous venovenous hemofiltration (CVVH) in ICU patients

Background

Supplementation of calcium during continuous venovenous hemofiltration (CVVH) with citrate anticoagulation is usually titrated using a target blood ionized calcium concentration. Plasma calcium concentrations may be normal despite substantial calcium loss, by mobilization of calcium from the skeleton. Aim of our study is to develop an equation to calculate CVVH calcium and to retrospectively calculate CVVH calcium balance in a cohort of ICU-patients.

Methods

This is a single-center retrospective observational cohort study. In a subcohort of patients, all calcium excretion measurements in patients treated with citrate CVVH were randomly divided into a development set (n = 324 in 42 patients) and a validation set (n = 441 in 42 different patients). Using mixed linear models, we developed an equation to calculate calcium excretion from routinely available parameters. We retrospectively calculated calcium balance in 788 patients treated with citrate CVVH between 2014 and 2021.

Results

Calcium excretion (mmol/24 h) was − 1.2877 + 0.646*[Ca]blood,total * ultrafiltrate (l/24 h) + 0.107*blood flow (ml/h). The mean error of the estimation was − 1.0 ± 6.7 mmol/24 h, the mean absolute error was 4.8 ± 4.8 mmol/24 h. Calculated calcium excretion was 105.8 ± 19.3 mmol/24 h. Mean daily CVVH calcium balance was − 12.0 ± 20.0 mmol/24 h. Mean cumulative calcium balance ranged from − 3687 to 448 mmol.

Conclusion

During citrate CVVH, calcium balance was negative in most patients, despite supplementation of calcium based on plasma ionized calcium levels. This may contribute to demineralization of the skeleton. We propose that calcium supplementation should be based on both plasma ionized calcium and a simple calculation of calcium excretion by CVVH.

Graphical abstract

The Incidence of Severe Hypercalcaemia-Induced Mental Status Changes in Patients Treated with Antibiotic-Loaded Calcium Sulphate Depot for Orthopaedic Infections

Local application of antibiotics with calcium-containing carrier materials (CCCM) might deliver large quantities of calcium, with some cases of hypercalcaemia reported. The incidence of symptomatic hypercalcaemia was estimated retrospectively in a consecutive, prospective series of patients treated between 10/2006 and 02/2019 with antibiotic-loaded CCCM for various orthopaedic infections. Risk factors were analysed. In the study period, 215 CCCM applications were performed. Two patients (0.9%) developed symptomatic hypercalcaemia. In one case, hypercalcaemia occurred 14 days after a second CCCM application during a staged septic hip revision. In the other case, hypercalcaemia became symptomatic six days after application of vancomycin-loaded CCCM in a component-retaining septic revision hip arthroplasty. In both cases, hypercalcemia was not imputable solely to the CCCM. Prolonged immobilization, renal impairment and other specific risk factors were present. Implantation of a CCCM for local application of antibiotics exposes the patient to large quantities of calcium during dissolution. This might induce symptomatic hypercalcaemia, a potentially life-threatening complication. The observed incidence of symptomatic hypercalcaemia remained rare (<1%). In some patients, compensatory mechanisms might be overwhelmed in the presence of other risk factors. Postoperative monitoring of calcaemia as well as elimination of risk factors is mandatory for all patients treated with CCCM.

Fine-tuned continuous renal replacement therapy with calcium-free dialysate to manage severe hypercalcemia refractory to medical and intermittent hemodialysis

Malignancy-related hypercalcemia is a leading cause of hypercalcemia among hospitalized patients that carries poor prognosis. Parathyroid carcinoma is a rare form of primary hyperparathyroidism that may be associated with PTH dependent hypercalcemia. Severe hypercalcemia is life-threatening and may require management in an intensive care unit by means of medical therapy consisting of volume expansion, loop diuretics, cinacalcet, calcitonin and bisphosphonates. Renal replacement therapy such as intermittent hemodialysis has been successfully used among patients with severe hypercalcemia who become refractory to medical treatment. However, little data are available for cases of severe refractory hypercalcemia that fail to respond to both optimal medical therapy and hemodialysis. Our present case illustrates the successful use of continuous veno-venous hemodiafiltration (CVVHDF) with calcium-free dialysate calcium and markedly increased dialysate flow rate, to restore normal calcemia in a patient with metastatic parathyroid carcinoma with severe refractory hypercalcemia.

Review of Hematological and Oncological Emergencies

Patients with hematological malignancies, both treated and untreated, or solid tumors undergoing treatment are at risk of life-threatening complications, which may present in the emergency department (ED). Such emergencies are diverse in etiology and often require prompt treatment. Traditional complications, such as febrile neutropenia, have had recent guideline updates, which incorporate new evidence and a new validated risk stratification tool. In addition, newer approaches to treatment, such as chimeric antigen receptor (CAR) T-cell therapy, are becoming more widely available and have unique associated toxicities. This review discusses the management of the following hematological and oncological emergencies likely to be encountered in the ED: febrile neutropenia, CAR T-cell toxicities, differentiation syndrome, tumor lysis syndrome, hypercalcemia of malignancy, and hyponatremia.

Case Report: Acute Kidney Injury Due to Chronic Milk-Alkali Syndrome in a Patient With Colon Cancer

BACKGROUND

Common causes of hypercalcemia include primary hyperparathyroidism and paraneoplastic syndrome of malignancy. Because of this, physicians can easily miss extrinsic causes of hypercalcemia such as milk-alkali syndrome in patients with cancer. We successfully treated a case of acute kidney injury due to severe hypercalcemia caused by milk-alkali syndrome due to long-term milk drinking in a patient with colon cancer.

CASE DESCRIPTION

A 62-year-old man was referred to nephrology for hypercalcemia and azotemia that was found during preoperative evaluation for colon cancer surgery. The patient had experienced several months of dizziness and anorexia. We started hemodialysis because hypercalcemia and azotemia were not improved despite large amounts of hydration and diuretics. We suspected paraneoplastic syndrome because of concomitant colon cancer and low intact parathyroid hormone (PTH). Renal microcalcifications were observed on ultrasonography. Metastatic calcifications of the lung and stomach were present, but no malignant metastasis appeared on bone scans. There was no evidence of metastatic malignant lesions on chest or abdominal enhanced computed tomography. PTH-related peptide was not detected. Thus, other causes of hypercalcemia beyond malignancy were considered. On history-taking, the patient reported consuming 1,000 to 1,200 mL of milk daily for the prior 3 months. Hypercalcemia was due to chronic milk-alkali syndrome. We advised withdrawal of milk and nutritional pills. Hemodialysis was stopped after 2 weeks since azotemia and hypercalcemia were resolving. Acute kidney injury was improved, and mild hypercalcemia remained when he underwent hemicolectomy after 1 month. Thereafter, serum calcium and creatinine remained normal at discharge and follow-up for 1 year in the outpatient clinic. However, lung calcifications still remained on bone scan after 1 year.

CONCLUSIONS

Chronic milk-alkali syndrome is a rare condition resulting from excessive calcium and alkali intake through various routes, like milk, nutritional supplements, and medicines for osteoporosis. Therefore, early management for hypercalcemia should include precise history taking including diet, previous diagnoses, and current medications.

Double Trouble: A Unique Case of Hypercalcemia Caused by Two Underlying Etiologies

Hypercalcemia has a variety of causes, with primary hyperparathyroidism and malignancies being the most frequently reported. We present the case of a patient presenting with chronic abdominal pain, constipation, and weight loss who was found to have hypercalcemia. The patient was initially diagnosed with colonic actinomycosis, but further investigations revealed an intra-abdominal diffuse large B-cell lymphoma (DLBCL). We suspect that the leading cause of hypercalcemia was the DLBCL, likely exacerbated by actinomycosis. Actinomycosis and DLBCL can have a similar presentation, so misdiagnosis or coexistence of both conditions should be suspected when a lack of response to one specific therapy is observed.

An unusual case of severe hypercalcemia: as dehydrated as a bone

Objective: Severe hypercalcemia is a medical emergency. Hyperparathyroidism, malignancy, vitamin D toxicity, infections such as tuberculosis, or systemic illness such as sarcoidosis are all possible etiologies. Among the less studied causes is dehydration. Our objective is to identify dehydration as an etiology of hypercalcemia.

Methods: Extensive literature review did not recognize dehydration as an etiology of hypercalcemia. We present a case of dehydration leading to severe hypercalcemia in a 60-years-old female with a presentation of altered mental status and corrected calcium level of 19 mg/dL in the absence of parathyroid abnormality, vitamin D toxicity, systemic disease, or malignancy.

Results: Dehydration caused hypercalcemia which led to a feed-forward mechanism and caused further worsening dehydration, worsening kidney function, and severe hypercalcemia. The patient responded very well to intravenous fluid and at the time of discharge had a serum calcium of 9.8 mg/dL with improved mental status back to the baseline.

Conclusion: Our literature review demonstrated many causes of hypercalcemia, with dehydration being exceptionally rare. It is our hope that this case report may serve as evidence of one such instance, allowing providers to keep a working differential of dehydration in severely elevated calcium levels.

Exploring the prognostic significance of preoperative high normocalcemia in epithelial ovarian carcinoma

PURPOSE

We investigated the association between serum ionized calcium and prognosis of EOC and determined the optimal cutoff value of ionized calcium level to predict the prognosis of EOC.

METHODS

The medical records of patients who were newly diagnosed with EOC from 2001 to 2016 were retrieved. Preoperative ionized calcium test was performed within 2 weeks before surgery, and the cutoff of high normocalcemia was defined based on the receiver operating characteristic (ROC) curve for recurrence. Cox proportional hazards regression models were used to identify independent prognostic factors for progression-free survival (PFS).

RESULTS

From 2001 to 2016, 83 patients diagnosed with EOC were identified at a single institution. The optimal cutoff value was set to 4.7 mg/dL (high normocalcemia vs. control group) by plotting the ROC curve for recurrence. Stages III/IV were more frequent in high normocalcemia, with borderline significance (72.9% vs. 52.2%, p = 0.053). Recurrence (67.6% vs. 43.5%, p = 0.029) and death (46.0% vs. 15.2%, p < 0.01) were significantly more frequent in the high normocalcemia group. In multivariate analysis, high normocalcemia (HR 1.9, 95% CI 1.03-3.61, p = 0.04), age (HR 1.04, 95% CI 1.01-1.08, p = 0.02), stage (HR 3.67, 95% CI 1.13-11.92, p = 0.03), residual tumor > 1 cm (HR 3.79, 95% CI 1.61-8.95, p < 0.01), and lymph node metastasis (HR 2.46, 95% CI 1.27-4.78, p < 0.01) were independent risk factors for recurrence.

CONCLUSION

This study showed positive association between relatively high level of ionized calcium level and recurrence risk of EOC. High normocalcemia showed the potential as a biomarker for prognosis of EOC.

Safety of Intravenous Bisphosphonates for the Treatment of Hypercalcemia in Patients With Preexisting Renal Dysfunction

BACKGROUND

Although intravenous (IV) bisphosphonates are first-line medications for the management of hypercalcemia, studies examining their use in patients with preexisting renal dysfunction are limited.

OBJECTIVE

The objective of this study is to describe the safety and efficacy of pamidronate and zoledronic acid in the treatment of hypercalcemia in patients with baseline renal dysfunction.

METHODS

A retrospective analysis was conducted of IV pamidronate and zoledronic acid in adult patients with hypercalcemia and creatinine clearance (CrCl) <60 mL/min. The primary endpoint was incidence of all-grade serum creatinine (SCr) elevations. Secondary endpoints included refractory hypercalcemia, hypocalcemia, osteonecrosis of the jaw (ONJ), corrected serum calcium (CSC) decrease ≥1.0 mg/dL by day 7 of bisphosphonate administration, and normalization of CSC ≤10.5 mg/dL by days 10 and 30.

RESULTS

A total of 113 patients were included (n = 55 pamidronate, n = 58 zoledronic acid). The primary endpoint of all-grade SCr elevation occurred in 28 (24.8%) patients. Grades 3/4 SCr elevations occurred in 10.9% of patients treated with pamidronate and 1.7% of patients receiving zoledronic acid. Approximately 16% and 14% of patients developed grades 1 and 2 hypocalcemia, respectively, and there were no cases of ONJ. Overall, 64.6% of patients achieved normalization of CSC by day 10, and there were no statistical differences between bisphosphonate type and renal function.

CONCLUSIONS AND RELEVANCE

The analysis suggests an association between IV bisphosphonates and increased rates of SCr elevations among patients with preexisting renal dysfunction. Future prospective studies are necessary to elucidate these findings.

Regional citrate anticoagulation versus low molecular weight heparin anticoagulation for continuous venovenous hemofiltration in patients with severe hypercalcemia: a retrospective cohort study

Purpose

We conducted a retrospective study to evaluate the efficacy and safety of regional citrate anticoagulation (RCA) versus those of low molecular weight heparin (LMWH) anticoagulation for CVVH in severe hypercalcemia patients.

Methods

Between January 2014 and May 2019, 33 severe hypercalcemia patients underwent CVVH. Patients were divided into the RCA and LMWH groups. Calcium-free replacement solution was used. Serum total calcium reduction rate (RRSeCa), filter lifespan, bleeding, totCa/ionCa ratio, citrate accumulation, and catheter occlusion were evaluated as outcomes.

Results

RCA and LMWH were employed for CVVH in 14 and 43 filters, respectively. RRSeCa was not significantly different between the LMWH and RCA groups (p = .320), but RCA-CVVH was more effective in reducing ionized calcium at half of the time points (p < .05). RCA significantly prolonged the median filter lifespan (>72 h vs. 24.0 h [IQR, 15.0–26.0], p = .012). The incidence of filter failure was 55.8% (24/43) in the LMWH group and 21.4% (3/14) in the RCA group (p = .033). The adjusted results demonstrated that RCA could significantly reduce the risk of filter failure (p = .043, 95% CI 0.059–0.957, HR = 0.238). No citrate accumulation or bleeding episodes were observed in the RCA-CVVH group. Seven bleeding episodes (7/43, 16.3%) occurred in the LMWH-CVVH group.

Conclusions

In patients with severe hypercalcemia who underwent CVVH, RCA more effectively decreased calcium levels and had a superior filter lifespan and no obvious adverse events compared with LMWH. Further prospective, randomized, controlled studies are warranted to obtain robust evidence.

Long-term hypervitaminosis D-induced hypercalcaemia treated with glucocorticoids and bisphosphonates

Hypercalcaemia is a common diagnosis with the majority of cases resulting from hyperparathyroidism or malignancy. We report a rare case of persistent symptomatic hypervitaminosis D-induced hypercalcaemia in an individual taking 50 000 IU of vitamin D supplement daily for several months following a diagnosis of vitamin D deficiency. His hypercalcaemia was initially treated with calcitonin and intravenous fluids, but due to recurrent symptomatic hypercalcaemia after discharge, additional treatment with glucocorticoids and bisphosphonates was warranted during his second admission. The pathophysiology of hypercalcaemia from vitamin D intoxication results from the long-term effects of vitamin D storage in adipose tissue. In the present case, we discuss this pathophysiology and treatment approaches in the context of increasing awareness of and testing for vitamin D deficiency, and growing access to over-the-counter supplements.

Primary Hyperparathyroidism Manifesting with Severe Hypercalcemia in a Nonagenarian Man: Pitfall of Common Imaging Techniques, Localization by 18F-Choline Positron Emission Tomography/Computed Tomography and Successful Management with Calcimimetics

A nonagenarian hypertensive man with chronic kidney disease (CKD) was admitted to the emergency department for gastrointestinal symptoms and worsening symptoms of depression. Severe hypercalcemia (15.3 mg/dL) was found and he was hospitalized. Fluids, loop diuretics and glucocorticoids were administered intravenously, which partially reduced calcium levels over a few days and improved his clinical condition. PTH levels proved increased (306 pg/mL) and 25-OHD levels were reduced; primary hyperparathyroidism (PHPT) was diagnosed. Neck ultrasonography (USG) did not show parathyroid enlargement, nor did 99mTechnetium-sestamibi (SESTAMIBI) scintigraphy reveal hyperfunctioning parathyroid glands. By contrast, 18F-choline PET/CT evidenced a nodule located close to the oesophagus, behind the right thyroid lobe, which proved compatible with a hyperfunctioning parathyroid gland. Since the patient declined surgery, and zoledronate was unfit owing to areas of rarefaction of the jaw, the calcimimetic cinacalcet was started; the dosage was progressively titrated up to 120 mg/day with normalisation of calcium levels over time. PTH levels, however, proved erratic and showed an upward trend over the first year of therapy; however its levels partially decreased following increase of vitamin D levels by replacement therapy. Cinacalcet is a useful and safe drug, which can normalise calcium levels and improve the clinical condition, even in very old patients with severe PHPT who decline or are unfit for surgery.

Persistent Increase in Serum 25-Hydroxyvitamin D Concentration in a Dog Following Cholecalciferol Intoxication

Cholecalciferol is becoming an increasingly utilized rodenticide in the United States due to changes implemented by the Environmental Protection Agency (EPA) to reduce unintended exposure of wildlife to second-generation anticoagulant rodenticides. The lipophilic properties of cholecalciferol and prolonged tissue elimination are well-documented; however, long-term clinical ramifications are unknown. This report describes unique clinicopathologic and treatment features during the acute phase of cholecalciferol rodenticide toxicosis in a 4-year-old neutered Shih-Tzu mix that presented for intermittent vomiting, anorexia, polyuria, and polydipsia. In addition, this report also highlights the potential benefit of serial measurements of serum 25-hydroxyvitamin D concentrations and long-term treatment in the chronic phase of cholecalciferol rodenticide toxicosis in dogs.

Successful Treatment for Hypercalcemia due to Cosecretion of Parathyroid Hormone-Related Protein and 1,25-Dihydroxyvitamin D3 in Non-Small-Cell Lung Cancer: A Case Report and Literature Review

Hypercalcemia of malignancy frequently manifests as paraneoplastic syndrome in patients with solid tumors. A 71-year-old man was diagnosed with stage IIIB lung squamous cell carcinoma. Laboratory examination revealed high serum calcium concentration with elevated serum parathyroid hormone-related protein (PTHrP) and 1,25-dihydroxyvitamin D₃ levels. As the patient did not respond to the initial treatment with calcitonin, extracellular fluid infusion, and chemotherapy, systemic prednisolone was administered additionally. Thus, the levels of serum calcium normalized and PTHrP and 1,25-dihydroxyvitamin D₃ decreased simultaneously. To our knowledge, this is the first case report on the successful treatment of hypercalcemia of malignancy caused by PTHrP and 1,25-dihydroxyvitamin D₃ cosecretion in a patient with lung cancer.

Off-label uses of denosumab in metabolic bone diseases

Denosumab (Dmab), a monoclonal antibody against the receptor activator of nuclear factor-κB (RANK) ligand (RANKL) which substantially suppresses osteoclast activity, has been approved for the treatment of common metabolic bone diseases, including postmenopausal osteoporosis, male osteoporosis, and glucocorticoid-induced osteoporosis, in which the pathway of the RANK/RANKL/osteoprotegerin is dysregulated. However, the imbalance of RANKL/RANK/osteoprotegerin is also implicated in the pathogenesis of several other rare metabolic bone diseases, including Juvenile Paget disease, fibrous dysplasia, Hajdu Cheney syndrome and Langerhans cell histiocytosis, thus rendering Dmab a potential treatment option for these diseases. Dmab has been also administered off-label in selected patients (e.g., with Paget's disease, osteogenesis imperfecta, aneurysmal bone cysts) due to contraindications or unresponsiveness to standard treatment, such as bisphosphonates. Moreover, Dmab was administered to improve hypercalcemia induced by various diseases, including primary hyperparathyroidism, tuberculosis and immobilization. The aim of this review is to summarize existing evidence on off-label uses of Dmab in metabolic bone diseases and provide opinion for or against its use, which should be always considered on an individual basis.

Epidemiology, clinical features, and management of severe hypercalcemia in critically ill patients

BACKGROUND

Severe hypercalcemia (HCM) is a common reason for admission in intensive-care unit (ICU). This case series aims to describe the clinical and biological features, etiologies, treatments, and outcome associated with severe HCM. This study included all patients with a total calcemia above 12 mg/dL (3 mmol/L) admitted in two ICUs from January 2007 to February 2017.

RESULTS

131 patients with HCM were included. HCM was related to hematologic malignancy in 58 (44.3%), solid tumors in 29 (22.1%), endocrinopathies in 16 (12.2%), and other causes in 28 (21.3%) patients. 108 (82.4%) patients fulfilled acute kidney injury (AKI) criteria. Among them, 25 (19%) patients required renal replacement therapy (RRT). 51 (38.9%) patients presented with neurological symptoms, 73 (55.7%) patients had cardiovascular manifestations, and 50 (38.1%) patients had digestive manifestations. The use of bisphosphonates (HR, 0.42; 95% CI, 0.27-0.67; P < 0.001) was the only treatment significantly associated with a decrease of total calcemia below 12 mg/dL (3 mmol/L) at day 5. ICU and Hospital mortality rates were, respectively, 9.9% and 21.3%. Simplified Acute Physiologic Score (SAPS II) (OR, 1.05; 95% CI 1.01-1.1; P = 0.03) and an underlying solid tumor (OR, 13.83; 95% CI 2.24-141.25; P = 0.01) were two independent factors associated with hospital mortality in multivariate analysis.

CONCLUSIONS

HCM is associated with high mortality rates, mainly due to underlying malignancies. The course of HCM may be complicated by organ failures which are most of the time reversible with early ICU management. Early ICU admission and prompt HCM management are crucial, especially in patients with an underlying solid tumor presenting with neurological symptoms.

Parathyroid hormone independent hypercalcemia in adults

Parathyroid independent hypercalcemia is characterized by suppressed parathyroid hormone (PTH) in the presence of hypercalcemia. Well known causes and mechanisms are redistribution of calcium from the skeleton, by malignant diseases; inadequately increased intestinal calcium uptake mediated by increased vitamin D activity, and reduced renal elimination due to medications. Frequent and infrequent causes are discussed, and more recent mechanistic models presented in this review. Most hypercalcemic conditions are stable and in equilibrium between the different organs, whereas the utmost severe cases are characterized by rapid rising calcium levels and renal failure, resulting in a vicious circle where a disequilibrium state is developed. Management and treatment depends on the underlying condition and severity. The aim of this review is to discuss non-parathyroid hypercalcemic conditions as seen in the modern clinic, with a focus on areas where recent gain of knowledge has been achieved.

Rapid Fire: Hypercalcemia

Hypercalcemia is commonly encountered in the clinical setting and requires identification by the clinician to avoid disastrous patient outcomes. The 2 most common causes are malignancy and hyperparathyroidism. The underlying cause for hypercalcemia may be readily known at presentation or may require further investigation. After identification, acuity of treatment will depend on severity of calcium level and symptoms. In the emergency setting, intravenous hydration with isotonic fluids is the treatment mainstay. Other commonly used medications to further decrease calcium include bisphosphates, calcitonin, steroids, and (rarely) furosemide. In life-threatening circumstances, dialysis can be implemented.

Inhibition of ROMK blocks macula densa tubuloglomerular feedback yet causes renal vasoconstriction in anesthetized rats

The Na⁺-K⁺-2Cl^- cotransporter (NKCC2) on the loop of Henle is the site of action of furosemide. Because outer medullary potassium channel (ROMK) inhibitors prevent reabsorption by NKCC2, we tested the hypothesis that ROMK inhibition with a novel selective ROMK inhibitor (compound C) blocks tubuloglomerular feedback (TGF) and reduces vascular resistance. Loop perfusion of either ROMK inhibitor or furosemide caused dose-dependent blunting of TGF, but the response to furosemide was 10-fold more sensitive (IC₅₀ = 10^-6 M for furosemide and IC₅₀ = 10^-5 M for compound C). During systemic infusion, both diuretics inhibited TGF, but ROMK inhibitor was 10-fold more sensitive (compound C: 63% inhibition; furosemide: 32% inhibition). Despite blockade of TGF, 1 h of constant systemic infusion of both diuretics reduced the glomerular filtration rate (GFR) and renal blood flow (RBF) by 40-60% and increased renal vascular resistance (RVR) by 100-200%. Neither diuretic altered blood pressure or hematocrit. Proximal tubule hydrostatic pressures (P_PT) increased transiently with both diuretics (compound C: 56% increase; furosemide: 70% increase) but returned to baseline. ROMK inhibitor caused more natriuresis (3,400 vs. 1,600% increase) and calciuresis (1,200 vs. 800% increase) but less kaliuresis (33 vs. 167% increase) than furosemide. In conclusion, blockade of ROMK or Na⁺-K⁺-2Cl^- transport inhibits TGF yet increases renal vascular resistance. The renal vasoconstriction was independent of volume depletion, blood pressure, TGF, or P_PT.

Prevalence of hypercalcemia among cancer patients in the United States

Hypercalcemia of malignancy (HCM) is a serious metabolic complication whose population‐based prevalence has not been quantified. Rates of HCM differ by tumor type, with highest rates reported in multiple myeloma and lowest among colorectal and prostate cancer patients. This analysis estimates HCM prevalence in the US. This retrospective study used the Oncology Services Comprehensive Electronic Records (OSCER) warehouse of electronic health records (EHR) including laboratory values from 569000 patients treated at 565 oncology outpatient sites. OSCER data were projected to the national level by linking EHR to claims data. Cancer patients included were ≥18 years, and had serum calcium (Ca) and albumin (for corrected serum Ca [CSC]) records. Period prevalence was estimated by HCM CTCAE grade, tumor type, and year (2009–2013). Estimates were adjusted to capture patients diagnosed with HCM outside oncology practices based on a subset of patients linkable to office and hospital data. The analysis included 68023 (2009) to 121482 (2013) cancer patients. In 2013, patients with HCM had a median of six Ca tests, 69.7% had chemotherapy, and 34% received bone modifying agents. HCM rates were highest for multiple myeloma patients (7.5% [2012]–10.2% [2010]), lowest for prostate cancer (1.4% [2012]–2.1% [2011]).The estimated adjusted annual prevalence of HCM from 2009 to 2013 was 95441, 96281, 89797, 70158, and 71744, respectively. HCM affected 2.0–2.8% of all cancer patients. EHR data from oncology clinics were critical for this study because these data contain results from laboratory studies (i.e., serum calcium values) that are routinely ordered in that setting. We estimated that the prevalence of HCM in the US in 2013 is 71744, affecting approximately 2% of cancer patients overall. This percentage differs by tumor type and appears to have decreased over the five‐year study period.

Hypercalcemia-Induced Hypokalemic Metabolic Alkalosis in a Multiple Myeloma Patient: The Risk of Furosemide Use

Hypercalcemia is often seen in patients with malignancies, and in the past treatment for this has traditionally included loop diuretics. Clinically, patients with hypercalcemia frequently present with polyuria and volume contraction which may be further exacerbated by diuretic therapy. In the lab, hypercalcemia has been shown to activate the calcium-sensing receptor in the thick ascending limb of Henle and inactivate the 2 chloride sodium potassium co-transporter and induce a hypokalemic metabolic alkalosis, an effect similar to that of the loop diuretic furosemide. We now report what may well be the first clinical correlate of this laboratory finding in a patient who developed a hypokalemic metabolic alkalosis as a consequence of severe hypercalcemia due to multiple myeloma and whose metabolic derangement was corrected without the use of a loop diuretic which may have exacerbated the electrolyte abnormalities.

Serum Calcium and Serum Albumin Are Biomarkers That Can Discriminate Malignant from Benign Pelvic Masses

BACKGROUND

Biomarkers that aid in the differential diagnosis of malignant pelvic masses from benign ones prior to surgery are needed in order to triage women with malignant masses to appropriate specialist care. Because high albumin-adjusted serum calcium predicted ovarian cancer among women without evidence of disease, we hypothesized that it might predict cancer among women with pelvic masses that were evident radiographically.

METHODS

We studied a cohort of 514 women with pelvic masses who underwent resection at Wake Forest University Baptist Medical Center from July 2009 through June 2013. We divided patients into a "training" set, to identify associations in the data, and a "testing" set, to confirm them. Data were obtained from medical records. A best fit model was selected using the Akaike Information Criterion.

RESULTS

Albumin-adjusted serum calcium was significantly higher in women with malignant versus benign masses (P = 0.0004). High normocalcemia, i.e., an albumin-adjusted serum calcium ≥ 10 mg/dL, occurred in 53% of women with malignant tumors versus 12% of benign tumors. High normocalcemia was associated with an approximately 14-fold increased risk of malignancy. The best fit model (Overa) included albumin, calcium, and nonlinear terms. Overa achieved an area under the curve of 0.83 with a sensitivity of 72% and specificity of 83%, a positive predictive value of 71% and a negative predictive value of 85%.

CONCLUSIONS

A model using serum calcium and serum albumin to predict malignancy in women with pelvic masses has high sensitivity and is economical.

IMPACT

Our model can help triage women with ovarian cancer to appropriate surgical care.

Point of care blood gases with electrolytes and lactates in adult emergencies

Point-of-care testing (POCT) is one of the formidable concept introduce in the field of critical care settings to deliver decentralized, patient-centric health care to the patients. Rapid provision of blood measurements, particularly blood gases and electrolytes, may translate into improved clinical outcomes. Studies shows that POCT carries advantages of providing reduced therapeutic turnaround time (TTAT), shorter door-to-clinical-decision time, rapid data availability, reduced preanalytic and postanalytic testing errors, self-contained user-friendly instruments, small sample volume requirements, and frequent serial whole-blood testing. However, still there is a noticeable debate that exists among the laboratorians, clinicians, and administrators over concerns regarding analyzer inaccuracy, imprecision and performance (interfering substances), poorly trained non-laboratorians, high cost of tests, operator-dependent quality of testing, and difficulty in integrating test results with hospital information system (HIS). On search of literature using Medline/Pubmed and Embase using the key phrases "ppoint-of-care test," "central laboratory testing," "electrolytes," "blood gas analysis," "lactate," "emergency department," "intensive care unit," we found that POCT of blood gases and selected electrolytes may not entirely replace centralized laboratory testing but may transfigure the clinical practice paradigm of emergency and critical care physicians. We infer that further comprehensive, meaningful and rigorous evaluations are required to determine outcomes which are more quantifiable, closely related to testing events and are associated with effective cost benefits.