Effect of Vitamin D Supplementation on Delayed Hyperphosphatemia in Pediatric Acute Lymphoblastic Leukemia Patients During Induction Chemotherapy.

OBJECTIVES: Vitamin D plays a role in maintaining bone health and calcium metabolism, but recent studies cast doubt on vitamin D supplementation's benefits in survivors of acute lymphoblastic leukemia (ALL). Vitamin D supplementation could increase serum phosphate through increased intestinal absorption of phosphate and suppression of parathyroid hormone, which would lead to decreased renal phosphate excretion. Because of the potential for renal injury during induction chemotherapy for ALL, Vitamin D supplementation's potential for increasing hyperphosphatemia could outweigh its suggested but unproven benefits. METHODS: To measure the interaction between vitamin D supplementation and phosphate during chemotherapy induction, a retrospective study was done. Demographic data; clinical information about the diagnosis; laboratory data regarding calcium, phosphate, and vitamin D concentrations; and medication histories were reviewed. RESULTS: A retrospective study of 41 children with ALL showed no statistically significant difference in the final phosphate concentrations that were obtained (4.41 mg/dL vs. 4.53 mg/dL, p = 0.635) with regard to their vitamin D supplementation status. Longitudinal effects with vitamin D and phosphate showed a trend toward increasing phosphate concentrations in patients who received supplemental vitamin D (0.035 vs. 0.010 mg/dL per day; p = 0.102). CONCLUSIONS: Vitamin D potentially poses a risk of hyperphosphatemia in children undergoing induction chemotherapy for ALL.

Spinal cord stimulation: indications and outcomes.

Spinal cord stimulation (SCS) is the most commonly used implantable neurostimulation modality for management of pain syndromes. In this paper the authors describe the current indications for SCS and its efficacy in the treatment of those diseases. Specifically, the literature on patient selection and outcomes after SCS for failed-back surgery syndrome (FBSS), refractory angina pectoris, peripheral vascular disease, and complex regional pain syndrome (CRPS) Type I was reviewed. Effective pain relief was obtained in 60 to 80% of patients with FBSS and CRPS Type I. Furthermore, these patients had significant improvements in quality of life (QOL) and a significantly greater chance of returning to work than patients who did not undergo SCS. The use of SCS in patients with inoperable angina (that is, refractory angina pectoris) resulted in significant decreases in chest pain and hospital admissions as well as increased exercise duration, with less morbidity than with open procedures that were performed for pain control only. Patients with inoperable PVD also demonstrated significant improvements in pain relief, QOL, and limb mobility. Reported complications were mostly related to hardware and were relatively minor. Review of randomized controlled studies supports the use of SCS as an effective treatment modality for pain associated with FBSS, refractory angina pectoris, peripheral vascular disease, and CRPS Type I.

Use of a sandwich technique to repair a left ventricular rupture after mitral valve replacement.

One difficulty with external repair of left ventricular rupture after mitral valve replacement is collateral bleeding in friable myocardium adjacent to the rupture. The bleeding is caused by tension on the closing sutures, whether or not pledgets have been used. We report the case of a 69-year-old woman who underwent an uneventful mitral valve replacement. After cardiopulmonary bypass was terminated, brisk bleeding started from high in the posterior left ventricular wall, typical of a type III defect. We undertook external repair, placing a plug of Teflon felt into the cavity of the rupture and sandwiching it into place with pledgeted mattress and figure-of-8 sutures. The space occupied by the plug decreased the distance needed to obliterate the defect and thereby reduced the tension on the sutures necessary to achieve hemostasis. This simple technique enabled closure of the defect and avoided collateral tears that would have compromised an otherwise successful repair. Two years postoperatively, the patient had normal mitral valve function and no left ventricular aneurysm. In addition to reporting the patient's case, we review the types of left ventricular rupture that can occur during mitral valve replacement and discuss the various repair options.

Anomalous origin of the middle meningeal artery from the posterior inferior cerebellar artery.

Various anastomosis and aberrant origins of the middle meningeal artery (MMA) have been documented in literature. However, there has been no report of its origin from the posterior inferior cerebellar artery (PICA) or its branches. In this report, we discuss an anomalous origin of the MMA from the PICA. Also, we discuss the embryological and anatomical development of the MMA. Imaging identification of the origin of the MMA is important while planning surgical and endovascular interventions in the region of the skull base.

A double-blind, randomized, controlled study of a "stress dose" of hydrocortisone for rescue treatment of refractory hypotension in preterm infants.

OBJECTIVE: To assess the effectiveness of a "stress dose" of hydrocortisone for rescue treatment of refractory hypotension and adrenocortical insufficiency of prematurity in very low birth weight (VLBW) infants. We hypothesized that significantly more VLBW infants who were receiving dopamine > or =10 microg/kg per min could wean off vasopressor support 72 hours after treatment with hydrocortisone. METHODS: A double-blind, randomized, controlled study was conducted in a university neonatal center. Forty-eight VLBW infants who had refractory hypotension and required dopamine > or =10 microg/kg per min were randomly assigned to receive a stress dose of hydrocortisone (1 mg/kg every 8 hours for 5 days; n = 24) or an equivalent volume of the placebo solution (isotonic saline; n = 24). RESULTS: The baseline clinical characteristics were similar between the groups. Serum cortisol concentrations were very low immediately before randomization in both groups of infants. Significantly more VLBW infants who were treated with hydrocortisone weaned off vasopressor support 72 hours after starting treatment. The use of volume expander, cumulative dose of dopamine, and dobutamine were significantly less in hydrocortisone-treated infants compared with control infants. In addition, the median duration of vasopressor treatment was halved in hydrocortisone-treated patients. Two versus 11 infants in the hydrocortisone and control groups required a second vasopressor for treatment of refractory hypotension. The trend (linear and quadratic) of the mean arterial blood pressure was also significantly and consistently higher in hydrocortisone-treated infants. CONCLUSIONS: A stress dose of hydrocortisone was effective in treating refractory hypotension in VLBW infants. Although routine and prophylactic use of systemic corticosteroids could not be recommended because of their potential adverse effects, this relatively low dose of hydrocortisone would probably be preferable to high-dose dexamethasone for treatment of refractory hypotension in emergency and life-threatening situations.