Vitamin B12 Screening in Cervical Spine Surgery Patients

Abstract

Introduction Vitamin B12 is very vital for the nervous system. Its deficiency can manifest with neurological symptoms like pain and paresthesias and in severe cases may cause not completely restorable neurological damage, especially in elderly patients. Methods The charts of 702 patients who underwent cervical spine surgery retrospectively reviewed and data collected . All patients were preoperatively seen by an internist who ordered Vit B12 levels for some of them. We used two thresholds for the diagnosis of vitamin B12 deficiency, 200 and 300 pg/mL as recommended by Yao et al. 1992. Data were also collected on gender, payor status, myelopathy, hemoglobin level, corpuscular parameters and glycosylated hemoglobin level (HbA1c). Vitamin B12 levels were compared between patients with HbA1c levels ≥ 6.1% and <6.1%. Differences between patients ≥ and < than the median age were studied. The median age of the patient cohort was 52. Results Hemoglobin level was recorded for 659 patients. Vit B12 levels were ordered for 291 patients only. Overall, 13.7% had decreased hemoglobin level (anemia), 30.2% had decreased Vit B12 levels by the 300 threshold, 6.9% had decreased Vit B12 levels by the 200 threshold, 6.3% decreased MCV (microcytosis), and 2.8% increased MCV (macrocytosis). Only four patients (0.7%), of whom older than 52, had decreased hemoglobin level and increased MCV (macrocytic anemia) and one patient (0.4%), who was also older than 52, had decreased hemoglobin level, increased MCV and Vit B12 level < 200 pg/mL (macrocytic anemia duo to Vit B12 deficiency). Dividing the patient sample into three age groups, <40, 40-59, and ≥ 60 years, we investigated the trend of cobalamin deficiency by age and found an increase in cobalamin deficiency after 40 from 0% to 7.4% (200 threshold). Uninsured patients (25%) using the 200 pg/mL threshold and workers’ compensation (54.5%) and uninsured patients (50.0%) had the highest rate of Vit B12 deficiency using the 300 pg/mL threshold. The few patients with macrocytic anemia (N=4) and macrocytic anemia due to Vit B12 deficiency (N=1) had health coverage. Conclusion Vit B12 deficiency in cervical spine surgery patients may not necessarily mean macrocytic anemia but may precede macrocytic anemia. Therefore, Vit B12 deficiency screening on the preoperative visit is warranted especially in uninsured or older patients or both. Preoperative treatment may be indicated and correlation with postoperative outcome is suggested for future research.