P80. The impact of body mass index (BMI) on postoperative outcomes following posterior spinal fusion in neuromuscular scoliosis

Abstract

BACKGROUND CONTEXT Obesity in the pediatric population is shown to be associated with adverse outcomes across varying specialties. The weight-outcome relationship in neuromuscular scoliosis has not been thoroughly investigated. PURPOSE To assess the impact of varying severity of BMI on 30-day outcomes following posterior spinal fusions in neuromuscular scoliosis. STUDY DESIGN/SETTING Retrospective review of prospectively collected data from a national pediatric surgical registry. PATIENT SAMPLE The 2012-2016 American College of Surgeons – National Surgical Quality Improvement (ACS-NSQIP) database was queried using Current Procedural Terminology codes 22800, 22802 and 22804 and International Classification of Diseases 9th Edition (ICD-9) diagnoses codes to identify patients undergoing posterior spinal fusion for neuromuscular scoliosis only. BMI was classified into four groups based on the Center for Disease Control (CDC) BMI-for-age percentile chart – normal weight (BMI ≥5th to OUTCOME MEASURES Thirty-day outcomes studied included prolonged length of stay >4 days, surgical site infections (superficial/deep/organ-space), wound dehiscence, pneumonia, unplanned intubation, cardiopulmonary complications (cardiac arrest or pulmonary embolism), renal complications (acute renal failure or progressive renal insufficiency), urinary tract infection, CNS complications (coma, stroke, seizure), venous thromboembolism, sepsis, bleeding requiring transfusion, re-operations, re-admissions and mortality outcomes. METHODS Pearson's Chi-square tests were used to assess for baseline differences and 30-day outcomes among the four BMI groups. Each 30-day outcome variable was then entered into a multivariate regression model while adjusting for clinically relevant baseline demographic and clinical characteristics (age, gender, steroid use, ventilator dependence, asthma, gastric disorder, developmental delay, seizure disorder, nutritional support requirement, length of fusion, primary vs revision procedure, use of osteotomy, and pelvic fixation) between the groups, to study the independent impact of varying severity of BMI on 30-day outcomes. RESULTS A total of 1,291 patients underwent posterior spinal fusion for neuromuscular scoliosis. A total of 695 (53.8%) were normal weight, 286 (22.2%) were underweight, 145 (11.2%) were overweight and 165 (12.8%) were obese. Obese patients vs normal weight patients were at a significantly higher risk of surgical site infections (OR 2.15; p=0.035), wound dehiscence (OR 1.58; p=0.037), urinary tract infections (OR 3.41; p=0.010) and 30-day readmissions (OR 1.94; p=0.029). Of note, overweight vs normal weight individuals had higher odds of cardiopulmonary complications (OR 8.82; p=0.024). No significant associations were seen for varying BMI and other 30-day complications, length of stay and mortality. CONCLUSIONS Obese neuromuscular patients undergoing PSF have higher odds of experiencing adverse outcomes, particularly surgical site infections, urinary tract infections and readmissions. Providers should promote prevention strategies, such as dietary modification and/or early physical activity in these high-risk patients to minimize the risks of experiencing complications in the acute post-operative period. FDA DEVICE/DRUG STATUS This abstract does not discuss or include any applicable devices or drugs.