Prevalence of previously unknown elevation of glycosylated hemoglobin in spine surgery patients and impact on length of stay and total cost.

BACKGROUND: Elevated levels of glycosylated hemoglobin (HbA1c) among spine surgery patients may have an impact on length of stay (LOS) and healthcare cost. MATERIALS AND METHODS: We retrospectively reviewed the charts of 556 spine surgery patients who underwent 1 of 3 types of surgery: lumbar microdiscectomy (LMD), anterior cervical decompression and fusion (ACDF), and lumbar decompression and fusion (LDF). Information was collected about their diabetes mellitus (DM) history and HbA1c levels. We used HbA1c 6.1% as the screening cutpoint. Percentages of nondiabetic patients, those with subclinical elevation of HbA1c and those with already known DM were calculated and statistical analysis was applied. RESULTS: After excluding the small group of well-controlled DM (n = 14), 72.4% of patients were nondiabetic, 14.3% were subclinical patients with previously unknown HbA1c elevation, and 13.3% were already known, confirmed DM patients. There were significant differences in the LDF group between the "No DM" and "Subclinical" groups (P < 0.05) in terms of cost and LOS (P < 0.05). Age and body mass index (BMI) were very significant predictors of total cost in spine surgery patients (P 0.05) in determining cost. CONCLUSIONS: There is a significant segment of spine surgery patients who were unaware of their elevated HbA1c status before their preoperative visit. These patients seem to utilize more healthcare resources, which is especially evident in the LDF group. We believe that HbA1c should be considered in the routine preoperative workup of spine surgery patients.

Causes and risk factors for postoperative fever in spine surgery patients.

Postoperative fever is a common dilemma faced by neurosurgeons. To study this problem, we prospectively collected patients who developed fever after spine surgery during the academic year 2007-2008 for whom the internist's consultation was requested. Eighty-five (85) patients were identified, of which 17 had an identifiable infectious cause for their febrile reaction (20%) - fever was attributed to urinary tract infection in 8 cases, pneumonia in 5 cases, wound infection in 3 cases (all lumbar), and cholecystitis in 1 case. The remaining 68 patients (80%) had no definitive diagnosis and fever was attributed to a peripheral venous line which, in this case, was replaced or discontinued. In 32 (37.6%) of the patients, the fever developed on postoperative day (POD) 2 or later. There was no statistically significant relationship between day of fever appearance and whether the fever was due to definite infection (P = 0.737). Comparing the basic group with another group of 456 spine surgery patients from 2006-2007 who might or might not have developed fever postoperatively using ANOVA, we found a significant difference in age (P = 0.011) and a very significant difference in hemoglobin level (P = 0.000) and HbA1c level (P = 0.000), but not in body mass index (BMI) (P = 0.289). Thus, most of the postoperative fever cases after spine surgery have no identifiable infectious focus and develop mainly in older patients with anemia and inadequately controlled HbA1c. A meticulous investigation of the source of fever including laboratory and radiological studies remains essential. Early mobilization is recommended for individuals undergoing lower spine surgery in order to decrease bacterial contamination from the gluteal cleavage.