Association Between Vitamin D Deficiency and Outcomes Following Spinal Fusion Surgery: A Systematic Review.

BACKGROUND: Vitamin D deficiency is a relatively common occurrence in patients presenting for spinal surgery; however, whether this abnormality has any effect on spinal fusion outcomes remains unclear. We performed a systematic review of the available literature relevant to the association between vitamin D deficiency and spinal fusion outcomes. METHODS: We conducted a systematic and critical review of recent literature following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The following databases were searched: MEDLINE/PubMed, Google Scholar, Cochrane, Web of Science, and Scopus. Key search terms were "vitamin D," "spinal surgery outcomes," "spinal fusion," and "pseudarthrosis." Papers included in the review were original research articles in peer-reviewed journals. The articles were thoroughly examined and compared on the basis of study design, outcomes, and results. RESULTS: A total of 5 studies were included in the qualitative analysis. In these studies, patients presenting with vitamin D deficiency achieved lower fusion rates and suffered higher rates of recurrent-persistent low back pain compared with patients with normal vitamin D levels. Studies examining the effect of postoperative vitamin D supplementation in deficient patients reported significant improvements in low back pain intensity, patient-reported outcomes scores, and fusion rates compared with baseline as well as with control groups. CONCLUSIONS: The literature suggests that patients presenting for spinal fusion may benefit from correction of vitamin D deficiency to maximize the chance of a successful arthrodesis and to achieve optimal surgical outcomes. Future prospective studies are needed to determine whether routine preoperative treatment of this metabolic derangement is warranted.

Evidence-based pharmacotherapy for cerebral vasospasm.

INTRODUCTION: The vast amount of literature on the pharmaceutical treatment of cerebral vasospasm after aneurysmal subarachnoid hemorrhage remains daunting. Optimal treatment regimens for patients can be obscured by studies not statistically powered to draw evidenced-based conclusions. METHODS: In this chapter, we reviewed the English literature using the National Library of Medicine for studies regarding pharmacotherapies for the treatment of cerebral vasospasm. These studies were then categorized according to the US Preventative Services Task Force ranking system for evidence based medicine and reviewed each pharmacotherapy for its efficacy in the treatment of cerebral vasospasm. RESULTS: Nimodipine (Nimotop), HMG Co-A reductase inhibitor (statins) and enoxaparin (Lovenox) were the only drugs with level-1 evidence available for the treatment of vasospasm from aneurysmal subarachnoid hemorrhage as defined by the US Preventative Services Task Force. CONCLUSION: As the understanding of the pathophysiological mechanisms of vasospasm after aneurysmal subarachnoid hemorrhage evolves in the basic science laboratory, novel medications are being trialed in humans. However, significantly more work must be carried out in this area before we have an effective medical treatment that can prevent or reverse the devastating events of cerebral vasospasm.