Hypercalcemia associated with extracorporeal life support in neonates

The Prolonged Use of VV ECMO Support in COVID-19: A Case Report

COVID-19 has resulted in unprecedented global health and economic challenges. The reported mortality in patients with COVID-19 requiring mechanical ventilation is high. VV ECMO may serve as a lifesaving rescue therapy for a minority of patients with COVID-19; however, its impact on overall survival of these patients is unknown. To date, few reports describe successful discharge from ECMO in COVID-19 after a prolonged ECMO run. The only Australian case of a COVID-19 patient, supported by prolonged VV ECMO in conjunction with prone ventilation, complicated by significant airway bleeding, and successfully decannulated after forty-two days, is described. VV ECMO is a resource-intense form of respiratory support. Providing complex therapies such as VV ECMO during a pandemic has its unique challenges. This case report provides a unique insight into the potential clinical sequelae of COVID-19, supported in an intensive care environment which was not resource-limited at the time, and adds to the evolving experience of prolonged VV ECMO support for ARDS with a goal to lung recovery.

Evaluation of Calcium Homeostasis and Dietary Supplementation for Pediatric and Neonatal Patients Receiving Extracorporeal Membrane Oxygenation Support

OBJECTIVES

Although the use of extracorporeal membrane oxygenation (ECMO) significantly improves survival in patients with persistent respiratory or cardiovascular failure, it also induces physiologic stress and disrupts homeostatic mechanisms. Patients undergoing ECMO support at our institution have required widely variable quantities of calcium supplementation for maintenance of normal calcium levels. Our primary objective was to assess the frequency of calcium abnormalities in pediatric and neonatal ECMO patients. Secondary objectives included quantifying electrolyte supplementation provided during ECMO and determining the relationships between calcium abnormalities and ECMO duration, mortality, and intensive care and hospital length of stay.

METHODS

We performed a single-center retrospective chart review of all patients less than 18 years of age who received ECMO support between July 1, 2013, and May 31, 2016. Clinical and laboratory data were reviewed for each patient for the duration of ECMO support, and the incidence of ionized calcium outside the reference range of 1.1 to 1.4 mmol/L beyond the first 24 hours of ECMO was recorded.

RESULTS

Seventy-eight patients were included in the study: 51 patients (65%) experienced at least one reading outside the normal ionized calcium range, while 27 patients (35%) were normocalcemic during their ECMO course. There were no differences between groups in the quantities of calcium, phosphate, or vitamin D administered during ECMO. Abnormal calcium levels were associated with a longer duration of ECMO (median 9 days vs 6 days, p = 0.0054), prolonged ICU length of stay (median 33 vs 18 days, p = 0.0055), and prolonged hospital length of stay (median 52 vs 40 days, p = 0.0239). No significant differences were found in survival to decannulation or survival to hospital discharge.

CONCLUSIONS

Calcium abnormalities occur frequently in pediatric and neonatal patients during ECMO and are associated with worse patient outcomes. The underlying physiology of these changes is thought to be related to ECMO-induced disruption of normal calcium homeostasis.

Hypercalcemic Disorders in Children

Hypercalcemia is defined as a serum calcium concentration that is greater than two standard deviations above the normal mean, which in children may vary with age and sex, reflecting changes in the normal physiology at each developmental stage. Hypercalcemic disorders in children may present with hypotonia, poor feeding, vomiting, constipation, abdominal pain, lethargy, polyuria, dehydration, failure to thrive, and seizures. In severe cases renal failure, pancreatitis and reduced consciousness may also occur and older children and adolescents may present with psychiatric symptoms. The causes of hypercalcemia in children can be classified as parathyroid hormone (PTH)-dependent or PTH-independent, and may be congenital or acquired. PTH-independent hypercalcemia, ie, hypercalcemia associated with a suppressed PTH, is commoner in children than PTH-dependent hypercalcemia. Acquired causes of PTH-independent hypercalcemia in children include hypervitaminosis; granulomatous disorders, and endocrinopathies. Congenital syndromes associated with PTH-independent hypercalcemia include idiopathic infantile hypercalcemia (IIH), William's syndrome, and inborn errors of metabolism. PTH-dependent hypercalcemia is usually caused by parathyroid tumors, which may give rise to primary hyperparathyroidism (PHPT) or tertiary hyperparathyroidism, which usually arises in association with chronic renal failure and in the treatment of hypophosphatemic rickets. Acquired causes of PTH-dependent hypercalcemia in neonates include maternal hypocalcemia and extracorporeal membrane oxygenation. PHPT usually occurs as an isolated nonsyndromic and nonhereditary endocrinopathy, but may also occur as a hereditary hypercalcemic disorder such as familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, and familial isolated primary hyperparathyroidism, and less commonly, as part of inherited complex syndromic disorders such as multiple endocrine neoplasia (MEN). Advances in identifying the genetic causes have resulted in increased understanding of the underlying biological pathways and improvements in diagnosis. The management of symptomatic hypercalcemia includes interventions such as fluids, antiresorptive medications, and parathyroid surgery. This article presents a clinical, biochemical, and genetic approach to investigating the causes of pediatric hypercalcemia. © 2017 American Society for Bone and Mineral Research.

Calcium and Phosphorous in Pediatric Parenteral Nutrition

Calcium (Ca) and phosphorus (P) are essential for various systemic functions, including bone mineralization. Adequate provision of Ca and P in pediatric parenteral nutrition (PN) solutions is necessary for skeletal growth and for the prevention of metabolic bone disease. The provision of adequate doses of Ca and P in pediatric PN solutions is complicated by the increased needs in preterm and term infants, solubility limitations, and venous access. Clinicians should be aware of the evidence that supports the optimal use of Ca and P in pediatric PN solutions, including studies that have evaluated dosing and solubility. The aim of this article is to review relevant literature and practices for the use of these two minerals in pediatric PN solutions. The vitamin D endocrine system, a critical component for Ca homeostasis and bone mineralization, is discussed, as well as clinical manifestations of metabolic bone disease and methods for its prevention, assessment, and treatment in pediatric patients receiving PN.

Calcium homeostasis disorder during and after neonatal extracorporeal membrane oxygenation

BACKGROUND AND AIMS

Extracorporeal membrane oxygenation (ECMO) is used during pediatric resuscitation in case of refractory hypoxemia or septic shock under maximum therapy. Previous studies describe calcium homeostasis dysregulation. The aim of this study was to confirmed of calcium homeostasis dysregulation in neonates under ECMO and supposed news explanation.

SUBJECTS AND METHODS

From November 2012 to July 2013, we performed a prospective single center observational study. Eleven neonatal patients were included. Blood was obtained before and during ECMO (day 7, 14 and 21) for parathyroid hormone (PTH), protein adjusted serum calcium, ionized calcium, magnesium, and calcitriol levels. All surviving patients underwent a consultation up to 6 months after ECMO weaning.

RESULTS

During ECMO PTH was inadequately high with normal serum calcium on day 7 (PTH: 73.54 ± 40 ng/l; calcemia: 2.33 ± 0.21 mmol/l), day 14 (PTH: 57.63 ± 29.57 ng/l; calcemia: 2.44 ± 0.43 mmol/l) and day 21 (PTH: 54.93 ± 8.43 ng/l; calcemia: 2.13 ± 0.09 mmol/l). The absence of correlation between serum calcium and PTH levels seem to confirm the dysregulation of PTH - serum calcium metabolism during ECMO. Six months after ECMO weaning, we noticed hypercalcemia with normal PTH.

CONCLUSIONS

We confirmed the existence of severe disturbances of calcium homeostasis in neonates on ECMO and supposed the possible damage of calcium regulation. We did not succeed in finding clear explanations of these disturbances.

Persistent pulmonary hypertension of the newborn: pathogenesis, etiology, and management

Persistent pulmonary hypertension of the newborn (PPHN) is characterized by severe hypoxemia shortly after birth, absence of cyanotic congenital heart disease, marked pulmonary hypertension, and vasoreactivity with extrapulmonary right-to-left shunting of blood across the ductus arteriosus and/or foramen ovale. In utero, a number of factors determine the normally high vascular resistance in the fetal pulmonary circulation, which results in a higher pulmonary compared with systemic vascular pressure. However, abnormal conditions may arise antenatally, during, or soon after birth resulting in the failure of the pulmonary vascular resistance to normally decrease as the circulation evolves from a fetal to a postnatal state. This results in cyanosis due to right-to-left shunting of blood across normally existing cardiovascular channels (foramen ovale or ductus arteriosus) secondary to high pulmonary versus systemic pressure. The diagnosis is made by characteristic lability in oxygenation of the infant, echocardiographic evidence of increased pulmonary pressure, with demonstrable shunts across the ductus arteriosus or foramen ovale, and the absence of cyanotic heart disease lesions. Management of the disease includes treatment of underlying causes, sedation and analgesia, maintenance of adequate systemic blood pressure, and ventilator and pharmacologic measures to increase pulmonary vasodilatation, decrease pulmonary vascular resistance, increase blood and tissue oxygenation, and normalize blood pH. Inhaled nitric oxide has been one of the latest measures to successfully treat PPHN and significantly reduce the need for extracorporeal membrane oxygenation.

Increased parathyroid hormone and decreased calcitriol during neonatal extracorporeal membrane oxygenation

OBJECTIVE

We noted that age-related normal calcium doses in neonates on venoarterial extracorporeal membrane oxygenation result in hypercalcemia. To avoid hypercalcemia and its potential consequences these infants are given one-half the normal calcium dose. We studied the pathogenesis of hypercalcemia and hypomagnesemia by evaluating calcitriol, intact parathyroid hormone, and calcitonin status during extracorporeal membrane oxygenation.

DESIGN AND SETTING

Prospective, observational study in the intensive care unit of a 225-bed tertiary care pediatric hospital.

PATIENTS AND PARTICIPANTS

Twelve neonates under 7 days old with severe pulmonary disease requiring extracorporeal membrane oxygenation.

MEASUREMENTS AND RESULTS

Blood was obtained for intact parathyroid hormone and calcitriol concentrations before cannulation, during (extracorporeal membrane oxygenation days 2, 4, and predecannulation in those on >6 days), and after decannulation on days 1 and 3. Calcitonin concentrations were measured before cannulation, during, and after decannulation in the last seven patients. Prior to cannulation parathyroid hormone was normal (1.4-5.7 pmol/l) and on day 2 increased to 7.8+/-8.4 pmol/l. Before cannulation calcitriol was 14.5+/-8.21 pmol/l (normal 41-143 pmol/l), and concentrations remained low until after decannulation. In three of the seven infants calcitonin concentrations (normal <73 ng/l) were above the upper limit of the assay (>1150 ng/l) prior to cannulation and during extracorporeal membrane oxygenation.

CONCLUSIONS

Regulation of the vitamin D-endocrine system during neonatal venoarterial extracorporeal membrane oxygenation appears to be aberrant compared to normal vitamin D-endocrine system regulation. The pathogenesis of this abnormality remains unclear and requires further study.

Perinatal calcium metabolism: physiology and pathophysiology

Disturbances in mineral homeostasis are common in the neonatal period, especially in premature infants and infants who are hospitalised in an intensive care unit. In many cases these disturbances are thought to be exaggerated responses to the normal physiological transition from the intrauterine environment to neonatal independence. By contrast, some disturbances in calcium homeostasis are the result of genetic defects, which in many instances can now be identified at the molecular level. In other cases hypocalcaemia or hypercalcaemia may result from pathological intrauterine conditions, birth trauma or stress, or fetal immaturity. Diagnosis and management of hypocalcaemia and hypercalcaemia in the neonate and infant requires specific knowledge of perinatal mineral physiology and the unique clinical and biochemical features of newborn mineral metabolism. In this chapter we will provide a brief overview of calcium metabolism with an emphasis on the neonatal transition, followed by discussion of the common causes of hypercalcaemia and hypocalcaemia.