263 - Outcomes after Lumbar Spine Surgery in Patients with Elevated Creatini...

#263 Outcomes after Lumbar Spine Surgery in Patients with Elevated Creatinine

Epidemiology/Natural History

Poster Presented by: K. Singh

Author(s):

A.J. Marquez-Lara (1)
S.V. Nandyala (1)
S.J. Fineberg (1)
M. Noureldin (1)
K. Singh (1)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, United States

Abstract

Introduction: Routine preoperative blood testing may reveal an elevated creatinine (Cr) level depending on the patient's comorbidities and fluid status. The effects of this abnormal lab value in patients who are scheduled to undergo elective lumbar spine surgery (LSS) are not well characterized. The purpose of this study was to analyze a population-based database to determine differences in patient demographics, preoperative conditions and surgical outcomes in patients with an elevated Cr prior to a LSS procedure.

Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was utilized to identify patients undergoing a LSS from 2006-2011. The resulting cohort was divided between patients who had an elevated preoperative Cr (Males >1.3mg/dL, Females >1.1mg/dL) and those with a normal Cr. Preoperative patient characteristics (demographics, comorbidities, preoperative lab values), surgery and hospital outcomes (e.g., operative time, length of stay (LOS), 30-day complication rates, and mortality) were compared between groups. SPSS v.20 was utilized for statistical analysis with independent t-tests and χ2-tests for continuous and categorical variables respectively. A p-value of≤ 0.001 was considered statistically significant. A multinomial regression analysis determined if an elevated Cr was an independent predictor of postoperative complications after controlling for demographics and comorbidities.

Results: A total of 18,647 LSS were identified from 2006-2011, of which 1,656 (8.9%) demonstrated an elevated preoperative Cr (mean=1.69mg/dL, SD 1.25). These patients were significantly older and demonstrated a greater number of comorbidities than the control group (p< 0.001). In addition, patients with an elevated Cr demonstrated greater ASA scores and underwent fewer outpatient procedures than patients with a normal Cr (p< 0.001). An elevated Cr was associated with a greater number of blood transfusions, operative time, postoperative complications and LOS (p< 0.001). However, the readmission, reoperation and mortality rates did not significantly differ between the cohorts. Finally after adjusting for demographics and other comorbidities an elevated Cr was not an independent predictor of any complication or mortality.

Conclusion: Patients with an elevated preoperative Cr were associated with higher ASA scores, longer operative time and a higher number of intraoperative blood transfusions. The elevated Cr cohort also demonstrated a greater number of postoperative complications and LOS. Despite the differences in preoperative comorbidities and peri-operative outcomes between the cohorts, regression analysis failed to demonstrate any significant differences in postoperative complications or mortality in patients with an elevated Cr. In view of these results, further investigation is warranted to clarify the negative association between an elevated Cr level and the peri-operative outcomes following a LSS procedure.