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.

Metabolic bone disease in gastrointestinal illness

Metabolic bone disease is often silent, often undiagnosed, and occurs frequently in patients with chronic gastrointestinal illnesses. Potentially modifiable risk factors, such as malnutrition, malabsorption, prolonged use of glucocorticoids, and a sedentary lifestyle, can lead to low bone mass, an increased rate of bone loss, and debilitating bone disease. This article explores common gastrointestinal illnesses that place patients at risk for developing metabolic bone disease. Concepts are presented to assist the practitioner in identifying patients at risk; clinical evaluation and diagnostic test selection are discussed, and therapeutic options for the prevention and treatment of metabolic bone disease in gastrointestinal illness are presented.

Metabolic bone disease and parenteral nutrition

Metabolic bone disease (MBD) is abnormal bone metabolism and includes the common disorders of osteoporosis and osteomalacia, which can develop in patients receiving long-term parenteral nutrition (PN). Patients who require long-term PN have significant gastrointestinal failure and malabsorption, which is generally caused by severe inflammatory bowel disease, intestinal ischemia, or malignancy. The exact cause of MBD in long-term PN patients is unknown, but its origin is thought to be multifactorial, with factors including underlying disease, effect of medications used to treat this disease (eg, corticosteroids), and various components of the PN solution. Caring for patients on long-term PN requires routine assessment and monitoring for MBD. Appropriate adjustments of the PN solution can help reduce the risk for developing PN-associated MBD and in some instances improve bone mineral density. Recent developments in pharmacologic treatment for osteoporosis show promise for patients with MBD receiving PN.

Pamidronate Treatment for Hypercalcemia in an Infant Receiving Parenteral Nutrition

A 17-day-old infant who was delivered 8 weeks premature underwent small bowel resection for necrotizing enterocolitis. During treatment with continuous infusions of furosemide and hydrocortisone, his total calcium concentration had increased. The calcium dose in his parenteral nutrition solution was decreased and then finally withheld. At 7 weeks of age and after 10 days of calcium-free parenteral nutrition, pamidronate 3 mg (1.1 mg/kg) in 60 ml of normal saline was infused over 6 hours. The infant's total serum calcium concentration decreased, but then 6 days later it had increased again; pamidronate 2 mg (0.7 mg/kg) in 40 ml of normal saline over 4 hours was administered. The patient demonstrated no signs or symptoms of adverse reactions to pamidronate. His serum calcium concentration returned to normal, and calcium-containing parenteral nutrition was tolerated. The use of pamidronate for treatment of hypercalcemia and chronic conditions that affect normal bone growth is increasing in children. Clinical trials in pediatric patients are necessary to determine how best to use bisphosphonates in this patient population.

Recent developments in home total parenteral nutrition

Home parenteral nutrition (HPN) support has been an advancing therapy in the past 30 years. Patients who previously had no options to sustain their lives are now able to live at home, maintain employment, and continue with most daily activities. Although this therapy has been innovative and successful, it requires great financial and professional resources. The expense of HPN makes most patients dependent on third-party payment, and the complications can result in frequent hospitalizations and may be life-threatening. For these reasons, extensive training of the patient and caregivers is necessary. Thorough and time-consuming monitoring by a multidisciplinary team of professionals is also essential. Home care and supply companies offer services that make the process of home TPN easier for the patient and the healthcare team. Advances in the area of home nutrition support are expected to continue as the demand for this therapy rises.