Liver transplantation in the pediatric patient is a durable procedure that provides excellent long-term survival. Although there have been overall improvements in patient outcome with increased experience, the effect is most pronounced for patients younger than 1 year of age. Retransplantation, although effective in a meaningful number of patients, continues to carry a progressive decrement in survival with the number of allografts performed. Use of living-related and in situ split-liver allografts has dramatically reduced waiting times for small children and has improved patient survival.

The histologic features of renal osteodystrophy and the prevalence of bone aluminum deposition in children receiving regular dialysis have not been described. Forty-four pediatric patients undergoing continuous ambulatory (CAPD) or cycling (CCPD) peritoneal dialysis had bone biopsies and deferoxamine (DFO) infusion tests; all were receiving oral calcitriol. Osteitis fibrosa (OF) was found in 39%, mild lesions (M) in 25%, normal histology (NH) in 16%, aplastic lesions (AP) in 11%, and osteomalacia (OM) in 9%. Bone surface aluminum (SA) was present by histochemical staining in 10 out of 20 given aluminum-containing phosphate-binding agents and in 0 of 24 treated with calcium carbonate; chi 2 = 15.5, P less than 0.0001. Serum biochemistries and DFO infusion tests failed to predict bone histology, but plasma aluminum levels were markedly elevated and bone aluminum content was highest in patients with OM. Bone formation rate (BFR) correlated with serum parathyroid hormone (PTH), r = 0.55, P less than 0.001; BFR was inversely related to bone aluminum content (r = -0.42, P less than 0.01), even in patients with OF (r = -0.66, P less than 0.05). All patients with SA greater than 30% had normal or reduced BFR when compared to those with SA less than 30%; chi 2 = 12.2, P less than 0.005. Based on SA greater than 30%, six patients were classified as aluminum-related bone disease: three OM, one AP, and two NH. Two-thirds of pediatric patients undergoing CAPD/CCPD have persistent hyperparathyroidism despite treatment with calcitriol, but aluminum can adversely affect BFR when SA exceeds 30% regardless of histologic lesion or serum PTH level.

Critical care medicine developed out of other subspecialties' need to provide care for their most critically ill patients. Advanced technologies, the understanding of the pathophysiology of critical illness, and the development of the multidisciplinary team have made this care possible. Pediatric critical care medicine emerged in the 1960s and has expanded dramatically since then. The field has made major advances in the areas of lung injury, sepsis, traumatic brain injury, and postoperative care. We review here the evolution of modern pediatric critical care medicine from its roots in general pediatric and cardiac surgery, adult respiratory care medicine, neonatology, and pediatric anesthesiology to its current state as a unique discipline. Pediatric intensive care has only been recognized as a distinct subspecialty for 20 y. The specialty grew out of a need for increasingly complex postoperative management, in the face of advances in surgical and medical subspecialties, and the development of sophisticated life-support technology. The intensivist now directs a multidisciplinary team that includes other subspecialists, nurse specialists, respiratory therapists, nutritionists, pharmacists, social workers, clergy, physical therapists, occupational therapists, and others. The pediatric intensivist's role is to provide supportive care during cardiorespiratory and/or multi-organ failure or recovery from surgical interventions or trauma. Intensivists coordinate complex treatment plans with multiple participants to further the care of critically ill children. DEVELOPMENT OF THE PEDIATRIC INTENSIVE CARE UNITA number of factors led to the development of the subspecialty of pediatric critical care medicine. In 1992, John Downes identified five crucial fields of medicine in the 1950s that led to the emergence of pediatric critical care: adult respiratory intensive care, neonatology and neonatal intensive care, pediatric general surgery, pediatric cardiac surgery, and pediatric anesthesiology (1).From the 1930s to 1950s, adult respiratory intensive care units were created to battle the scourge of the polio epidemic with "iron lung" ventilators. Out of necessity, these units also cared for children with polio (1). The neonatologists, in their newly created neonatal intensive care units, developed procedures for nutritional and environmental support of sick newborns and premature infants along with ventilation techniques and monitoring for treating hyaline membrane disease (also known as respiratory distress syndrome). The understanding and use of surfactant and continuous positive airway pressure mechanical ventilation greatly improved survival of infants with respiratory distress syndrome. By the 1960s, many infants with respiratory distress syndrome, who received extended mechanical ventilation, developed persistent lung disease, termed bronchopulmonary dysplasia (2). This created a need for extended care of older infants and children with the ensuing chronic lung disease (1).During this period, advances in pediatric surg...