Immobilization-related hypercalcaemia--a possible novel mechanism and response to pamidronate

A Rare Case Report of Immobility-Induced Hypercalcemia in an Infant

Immobility-induced hypercalcemia is a rare cause of hypercalcemia in children, and to our knowledge it has never been reported in an infant. Infants and children are in a state of high bone turnover. Therefore, they are prone to the imbalance of osteoblastic and osteoclastic activity that occurs with prolonged immobilization, leading to hypercalcemia. Here we present the case of an infant with hypercalcemia who presented with fatigue, irritability, and failure to thrive after prolonged immobilization. Therapeutic interventions were conservative and included hydration and increased mobility leading to complete resolution. This case highlights the importance of including this rare entity in a differential diagnosis of hypercalcemia as well as screening postsurgical patients with prolonged immobility for hypercalcemia.

Denosumab for treatment of immobilization-related hypercalcaemia in a patient with advanced renal failure

We describe the case of a young adult with immobilization-related hypercalcaemia and advanced renal insufficiency. Because of the uncertain safety profile of bisphosphonates in such patients, only a low dose of pamidronate was administered twice. This did not result in a sufficient decrease in the serum calcium concentration nor was the decrease sustained. We decided to administer a single dose of denosumab, a monoclonal antibody against the receptor activator of nuclear factor-κB ligand, a new antiresorptive agent registered for use in osteoporosis. This resulted in rapid and sustained decrease in the serum calcium concentration. Transient hypocalcaemia ensued with normalization after vitamin D supplementation. Furthermore, we summarize what is known about hypercalcaemia caused by immobilization.

At the bottom of the differential diagnosis list: unusual causes of pediatric hypertension

Hypertension affects 1-5% of children and adolescents, and the incidence has been increasing in association with obesity. However, secondary causes of hypertension such as renal parenchymal diseases, congenital abnormalities and renovascular disorders still remain the leading cause of pediatric hypertension, particularly in children under 12 years old. Other less common causes of hypertension in children and adolescents, including immobilization, burns, illicit and prescription drugs, dietary supplements, genetic disorders, and tumors will be addressed in this review.

Pamidronate treatment in acute vitamin D intoxication

Management with glucocorticoid, high iv fluid saline intake, furosemide and calcitonin may not result in a favorable reduction of hypercalcemia and may cause several side effects in infants with acute vitamin D intoxication. The bisphosphonate pamidronate, a specific inhibitor of bone resorption through osteoclast mediation was successfully used in a 6-month old infant with acute vitamin D intoxication managed in the Pediatric Emergency and Intensive Care Unit, after an ineffective trial of hydration, furosemide, calcitonin and prednisolone. After a double infusion of pamidronate on two consecutive days (1 mg/kg/day), an early and safe correction of hypercalcemia/hypercalciuria was supplied. Pamidronate therapy may be considered in patients with hypercalcemia secondary to acute vitamin D poisoning.

Increased bone resorption in the critically ill: association with sepsis and increased nitric oxide production

OBJECTIVE

Cytokines stimulate nitric oxide production in bone, and high concentrations of cytokine-induced nitric oxide inhibit bone resorption in vitro. This has led to the suggestion that nitric oxide may protect against bone loss in inflammatory and infectious diseases. In this study, we sought to determine whether nitric oxide generated as the result of sepsis was associated with suppression of bone resorption in vivo.

DESIGN

Observational study.

SETTING

Adult intensive care unit of a university hospital.

PATIENTS

We studied 20 consecutive patients who had been admitted to the intensive care unit because of sepsis and three who had been admitted because of trauma. Controls were 29 patients with noninflammatory musculoskeletal conditions.

INTERVENTIONS

Standard clinical care.

MEASUREMENTS AND MAIN RESULTS

Bone resorption was assessed by measurement of urinary pyridinoline and deoxypyridinoline as a ratio to urinary creatinine. Nitric oxide production was assessed by measuring the ratio of the nitric oxide breakdown products nitrate and nitrite to urinary creatinine. Urinary nitrate and nitrite/creatinine values were significantly higher in intensive care patients with sepsis (mean +/- sem, 0.164 +/- 0.053 micromol/mmol) than in intensive care patients with trauma (0.066 +/- 0.008) and controls (0.079 +/- 0.007; p =.007 between groups). Urinary pyridinoline/creatinine values were increased in intensive care patients with sepsis (553.8 +/- 193 nmol/mmol) and trauma (238 +/- 32) compared with controls (44.7 +/- 2.6; p =.001 between groups), and similar differences between the groups were observed for deoxypyridinoline/creatinine values: intensive care patients with sepsis, 86.4 +/- 24.0; intensive care patients with trauma, 46 +/- 4.2; and controls, 10.3 +/- 0.7 (p =.001).

CONCLUSIONS

Critically ill patients with sepsis have increased nitric oxide production and increased bone resorption, whereas trauma patients have increased bone resorption in the presence of normal nitric oxide production. High concentrations of nitric oxide generated during the course of infection do not afford significant protection against accelerated bone resorption.

Symptomatic hypercalcemia of immobilization in a patient with end-stage renal disease

The phenomenon of hypercalcemia in immobilization is well known, but there is limited awareness of the potential for this complication in patients with end-stage renal disease (ESRD) on maintenance hemodialysis with reduced capacity for disposition of calcium. We describe such a patient who showed a calcemic response to just 3 days of immobilization in the setting of an acute illness marked by coma. Despite intensive initial therapy for hypercalcemia, including withdrawal of all calcium products and daily hemodialysis treatments using low calcium baths, her serum calcium rose to 14.0 mg/dL during the hospitalization; this metabolic abnormality appeared to perpetuate her stuporous state. Mobilization as an outpatient was the most effective therapy. Extensive testing was performed to rule out other causes for this patient's hypercalcemia. Greater recognition of acute hypercalcemia in patients with ESRD immobilized by various illnesses would preclude unnecessarily expensive and invasive testing for other causes of hypercalcemia.

Influence of immobilization upon calcium metabolism in the week following hemiplegic stroke

Hip fractures on the paretic side are a serious post-stroke complication and may result from disuse hemiosteopenia, hypovitaminosis D, and an increasing risk of falls. To evaluate short-term immobilization effects, we assessed calcium metabolism in 89 patients 1 week after the hemiplegic stroke and in 36 controls. Patient activity was rated using the Barthel index (BI). Sera from stroke patients and control subjects were assayed for ionized calcium, parathyroid hormone (PTH), 25-hydroxyvitamin D (25-OHD), 1, 25-dihydroxyvitamin D (1,25-(OH)(2)D), bone Gla protein (BGP; a bone formation marker) and pyridinoline cross-linked carboxy-terminal telopeptide of type I collagen (ICTP; a bone resorption marker). Patients' serum concentrations of ionized calcium and ICTP were higher than in controls and correlated negatively with BI; their BGP concentrations were low, correlating positively with BI. Concentrations of serum 25-OHD, 1,25-(OH)(2)D, and PTH also were low; serum 25-OHD was at a deficient level (<10 ng/ml) in nine patients (10%), an insufficient level (10-20 ng/ml) in 56 (63%), and a sufficient level (>20 ng/ml) in only 24 (27%). PTH correlated negatively with calcium and 1,25-(OH)(2)D. Hypovitaminosis D is common in acute stroke patients. Immobilization from acute hemiplegia can increase bone resorption and serum calcium, and inhibit PTH secretion and 1,25-(OH)(2)D production to add to the effects of hypovitaminosis D.

Immobilization hypercalcemia treatment with pamidronate disodium after spinal cord injury

OBJECTIVE

To review the use of pamidronate to treat immobilization hypercalcemia after acute spinal cord injury (SCI) in 9 cases.

DESIGN

Retrospective case series.

SETTING

Two inpatient rehabilitation programs, one pediatric and one adult, in the Northwest Regional Spinal Cord Injury System.

PATIENTS

Patients with acute SCI who developed immobilization hypercalcemia that was treated with pamidronate.

RESULTS

Nine patients (7 men, 2 women), ages 15 to 41 yrs, with SCI (8 tetraplegia, 1 paraplegia) were treated using pamidronate between 1994 and 1998. A single dose of 60 mg of pamidronate resolved the hypercalcemia or its symptoms in 7 (78%) patients within days. One patient required a second dose (90 mg) and one patient required three additional doses (the fourth at 90 mg) to achieve resolution of the hypercalcemia or symptoms. Side effects were mild and included drug-related fever in one patient and transient asymptomatic hypocalcemia in four patients.

CONCLUSION

Pamidronate was effective in treating immobilization hypercalcemia caused by SCI. Its advantages include its effectiveness, the duration of treatment, ease of administration, and elimination of the need for long-term intravenous saline or daily medications.

Intravenous pamidronate attenuates bone density loss after acute spinal cord injury

OBJECTIVE

To compare the effects of a 6-month treatment with intravenous pamidronate (30-mg infusion once per month) to conventional rehabilitation without pamidronate on bone density of the spine and leg bones and on the excretion rate of N-telopeptide, a urinary marker of bone catabolism, in acutely spinal cord injured patients.

DESIGN

A nonrandomized control trial in which 24 spinal cord injured subjects entered the study within 6 weeks of their injury. Fourteen subjects received pamidronate; 10 did not.

OUTCOME MEASURES

Bone density measurements by dual x-ray absorptiometry were performed before the initial treatment (within 6 weeks of the injury) and at 3, 6, and 12 months postinjury and was the primary efficacy parameter. Urine for N-telopeptide levels was the secondary efficacy parameter.

RESULTS

After acute spinal cord injury, patients treated with intravenous pamidronate had significantly less bone density loss compared with those who did not receive pamidronate (parametric ANOVA, p<.02). Also, ambulatory subjects had significantly less bone density loss over the study period (p<.05) than nonambulatory subjects. In general, a high excretion level of the urinary bone-breakdown product N-telopeptide was found before intravenous pamidronate treatment, followed by a dramatic reduction in excretion after pamidronate treatment. Ambulatory subjects excreted significantly less N-telopeptide than motor-complete subjects at all time points.

CONCLUSION

Intravenous pamidronate treatment and ambulatory ability in the first 6 months after an acute spinal cord injury prevents bone density loss.

Survival in breast cancer patients after the first episode of hypercalcaemia

OBJECTIVES

To investigate hypercalcaemia (serum ionized calcium (S-Ca2+) > 1.35 mmol L(-1)) in breast cancer patients before and after the introduction of bisphosphonates and the effect of disease- and treatment-related factors on survival.

DESIGN

Prospective and retrospective registration of covariates.

SETTING

A department of oncology in a university hospital.

SUBJECTS

A consecutive cohort of 212 hypercalcaemic patients never treated with bisphosphonate was identified prospectively (period 1) and 193 patients with metastases were classified into three groups: mild (S-Ca2+ < 1.48: n=102). moderate (1.48 < or = S-Ca2+ < or = 1.60; n=41). and severe hypercalcaemia (S-Ca2+ > 1.60 mmol L(-1); n=50). Fifty-one patients with severe hypercalcaemia all treated with bisphosphonate except one were identified retrospectively (period 2).

RESULTS

For period 1 median survival was 6.7 months. Survival was significantly decreased in the two groups with the highest initial S-Ca2+ (P < 0.0001). Median survival times in severely hypercalcaemic patients from periods 1 and 2 were 1.4 (9 5(% confidence interval 0.8-2.1) and 2.2 (95% confidence interval 1.3-3.1) months, respectively. In a Cox model for period 1 significant covariates were: WHO performance, extent of metastases, whether systemic anticancer treatment could be given, and haemoglobin, but not S-Ca2+.

CONCLUSION

Prognosis is poor in hypercalcaemic breast cancer patients with WHO performance 3-4 and advanced metastatic disease when effective systemic treatment can no longer be offered. Bisphosphonate treatment does not seem to improve survival in severe hypercalcaemia. Antihypercalcaemic treatment of mild malignancy-associated hypercalcaemia appears not to be vital. Therapeutic efforts should be aiming at patients with moderate hypercalcaemia.

Immobilization hypercalcemia in incomplete paraplegia: successful treatment with pamidronate

Immobilization hypercalcemia (IH) occurs in adolescent patients with high-level complete tetraplegia, but it has not been reported in patients with incomplete paraplegia. We describe two adolescent patients with low-level incomplete paraplegia who developed IH during comprehensive rehabilitation. Conventional therapies with hydration, diuresis, and calcitonin were not effective. Finally, a single-dose infusion of pamidronate, an amino-bisphosphonate, completely resolved the hypercalcemia. Although it has a pharmacologic profile similar to etidronate, pamidronate is more potent, being effective in a single dose, has fewer adverse effects, and has a longer action than etidronate. These features make pamidronate more suitable for the treatment of severe IH in rehabilitation settings. It is reasonable to consider immobilization as the cause of hypercalcemia in low-level incomplete paraplegic patients who have other contributing factors.

Treatment of immobilisation hypercalcaemia in acute intermittent porphyria: experience from three cases

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Pamidronate: an unrecognized problem in gastrointestinal tolerability

Pamidronate (aminohydroxypropylidine bisphosphonate, APD) is an effective agent for treatment of Paget's disease of bone, and it has also been thought to be effective for treatment of osteoporosis. We desired to study a newer, time-release preparation of pamidronate, and carried out a placebo-controlled, double-masked study of postmenopausal osteoporosis. The original formulation was in a rapidly dissolving gelatin capsule. We encountered four episodes of esophagitis in 49 enrolled patients. We therefore discontinued treatment with this preparation and later began the study again using a standard tablet preparation. We encountered an additional case of erosive esophagitis in 1 patient of 40 receiving this tablet preparation. No patient was receiving concomitant medication which could cause esophagitis. Two of the patients gave a past history of hiatal hernia and 1 gave a history of gastric ulcer 27 years previously. The diagnosis of esophagitis was confirmed in all cases by endoscopy. Healing of the esophagitis promptly ensued after discontinuation of the pamidronate and the use of antacid medication.

Histomorphometric evidence for osteoclast-mediated bone resorption in metastatic breast cancer

We studied bone biopsies from 65 normocalcaemic women with breast cancer and predominantly osteolytic bone metastases in order to examine the pathophysiology of bone destruction in metastatic bone disease. Quantitative histomorphometric measurements were made at sites of tumour involvement, at sites adjacent to tumour tissue and at sites distant from tumour tissue. There were no significant differences in bone volume or in indices of bone resorption or formation between biopsies taken from sites distant from tumour and the controls. Bone resorption, as judged by eroded surface, increased progressively from bone distant from tumour to tumour-laden bone. The number of osteoclasts was significantly increased in bone immediately adjacent to tumour and within metastases. There was no decrease in the ratio of osteoclast to eroded surface in breast cancer compared to controls suggesting that increased resorption in breast cancer was mainly osteoclast mediated and locally activated by the tumour. Two thirds of the biopsies taken from tumour involved regions showed osteosclerosis with woven bone formation. The volume of the pre-existing lamellar trabecular bone was lower than normal in 75% of these biopsies, suggesting that bone resorption must have been increased before the onset of woven bone formation. Since all patients were receiving hormonal treatment or chemotherapy, it is likely that osteosclerosis at sites of previous resorption mainly resulted from the basic cancer treatment as a sign of response to treatment. Osteoclastic bone resorption was, however, not completely inhibited by the active cancer treatment.

Treatment of hypercalcaemia with pamidronate in patients with end stage renal failure

Pamidronate was given to 10 patients with end stage renal failure who had become symptomatically hypercalcaemic due to the use of calcium based phosphate binders and alphacalcidol. All patients were initially treated with rehydration, increased dialysis and withdrawal of drugs, however despite this they remained symptomatic and the serum calcium remained elevated, mean 3.89 mmol/l (range 3.44-4.74). Pamidronate was given, and the serum calcium had declined to 2.92 mmol/l (2.79-3.84), p < 0.01 by the third day. The reduction in serum calcium observed with pamidronate was more rapid than that in 9 patients who developed asymptomatic hypercalcaemia, mean serum calcium 3.45 mmol/l (3.4-3.56), with an actual median reduction of 0.72 mmol/l (0.37-1.30) in the pamidronate group after 3 days compared to 0.20 mmol/l (0.10-0.52) in the conservatively treated asymptomatic group, p < 0.01, and a median percentage decrease of 19% (10-30) in the pamidronate group and 6% (3-15) in the asymptomatic group, p < 0.01. In this study pamidronate was a safe and effective agent in reducing serum calcium in a group of hypercalcaemic dialysis patients.

Secondary osteoporosis

Osteoporosis with attendant increased fracture risk is a common complication of many other diseases. Indeed, almost all chronic diseases make some impact on life-style, usually by restricting physical activity and hence reducing the anabolic effect of exercise and gravitational strains on the skeleton. Restricted appetite and modified gastrointestinal tract function is another commonplace finding that has an impact on bone nutrition and synthesis, as on other systems. Sex hormone status is of particular importance for the maintenance of the normal skeleton, and the postmenopausal woman is at particular risk for most causes of secondary osteoporosis. In dealing with secondary osteoporosis in the hypo-oestrogenic woman, the question of giving hormone replacement therapy in addition to other disease-specific therapy should always be considered, as, for example, in a young amenorrhoeic woman with Crohn's disease. Similarly, in hypogonadal men the administration of testosterone is useful for bone conservation. The wider availability of bone densitometry ought to make us more aware of the presence of osteoporosis in the many disease states discussed above. This is particularly important as the life span of such patients is now increased by improved management of the underlying disease process in many instances. Even in steroid-induced osteoporosis--one of the commonest and most severe forms of osteoporosis--we now have some effective therapy in the form of the bisphosphonates and other anti-bone-resorbing drug classes. The possibility of prophylaxis against secondary osteoporosis has therefore become a possibility, although the very long-term effects of such drug regimens are still unknown. In some situations, such as thyrotoxicosis, Cushing's syndrome and immobilization, spontaneous resolution of at least part of the osteoporosis is possible after cure of the underlying problem. The shorter the existence of the basic problem, the more successful the restoration of the skeleton appears to be. A useful credo for clinicians with respect to secondary osteoporosis is: to think of it; to use specific therapy for the underlying disease; to reduce or remove completely any relevant drug or toxic material; to optimize physical activity and general nutrition; to treat hypogonadism if present and feasible; and to consider the use of specific anti-bone-resorbing or other bone active drugs.

Severe hypercalcaemia four months after acute oliguric renal failure--successful treatment with intravenous clodronate

A 33 year old man developed acute oliguric failure lasting 66 days, eight days after admission with multiple gun shot wounds. On day 99 after admission, serum calcium was elevated mildly at 2.54 mmol/l (normal range 2.1-2.5 mmol/l). Serum parathormone was undetectable. He was discharged soon afterwards. He presented again on day 164 with nausea, vomiting and blurred vision. Fundoscopy revealed an ischaemic retinopathy and extensive keratopathy. Serum calcium was 3.48 mmol/l and serum creatinine 262 umol/l (normal range 40-110 umol/l). Repeat parathormone was undetectable and there was no evidence of myeloma, sarcoidosis or malignancy. Following treatment with intravenous saline and frusemide, serum calcium fell to a nadir of 3.05 mmol/l. On day 168 an infusion of sodium clodronate 300 mg was given. Twenty-four hours later serum calcium was 2.65 mmol/l and 48 hours later calcium was 2.26 mmol/l. Normocalcaemia was maintained for 17 days and severe hypercalcaemia never recurred. This is the first report in which biphosphonates have been successfully used to treat hypercalcaemia following acute renal failure thus obviating the need for further dialysis.

Pamidronate. A review of its pharmacological properties and therapeutic efficacy in resorptive bone disease

Pamidronate [aminohydroxypropylidene diphosphonate disodium (APD), disodium pamidronate] is an orally and intravenously active amino-substituted bisphosphonate which produces potent and specific inhibition of bone resorption at doses devoid of any significant detrimental effect on bone growth and mineralisation. Clinical trials indicate that pamidronate is effective in a variety of conditions characterised by pathologically enhanced bone turnover, including Paget's disease, hypercalcaemia of malignancy, osteolytic bone metastasis, steroid-induced osteoporosis and idiopathic osteoporosis. Pamidronate is highly effective in restoring normocalcaemia in patients with hypercalcaemia of malignancy associated with bone metastases but, in common with other bisphosphonates, is marginally less effective against humoral hypercalcaemia of malignancy. Comparative studies in this area have suggested that, at therapeutic doses, pamidronate has a more pronounced calcium-lowering action than etidronate (etidronic acid) and clodronate (clodronic acid) and provides a longer period of normocalcaemic remission. In Paget's disease arrest and, in some patients, reversal of the progression of osteolytic lesions by pamidronate is associated with a sustained reduction in bone pain, improved mobility and a possible reduced risk of bone fracture. In patients with osteolytic bone metastasis pamidronate reduces skeletal morbidity and slows the progression of metastatic bone destruction. Long term use of low-dose pamidronate in conjunction with conventional antiosteoporotic therapy may halt bone loss in steroid-induced and idiopathic osteoporosis. Pamidronate appears to represent a valuable addition to the drugs currently available for the treatment of symptomatic Paget's disease and cancer-associated hypercalcaemia, and shows promise in the treatment of osteolytic bone metastasis and osteoporosis.