205. Malnutrition increases risk of complications following posterior lumbar fusion independent of body mass index

• Published in: The spine journal 2022-09, Vol.22 (9), p.S108-S109
• Main Authors: Johnson, Keir, Alsoof, Daniel, McDonald, Christopher, Berreta, Rodrigo Saad, Cohen, Eric, Daniels, Alan H.
• Format: Article
• Language: English
• ISSN: 1529-9430; 1878-1632
• DOI: 10.1016/j.spinee.2022.06.225

The number of complicated elective posterior lumbar fusion (PLF) cases has increased over the last several decades. Modifiable risk factors are important to identify for preoperative optimization in patients with multiple comorbidities to avoid complications. Malnutrition is a modifiable risk factor that may be linked to worse outcomes following PLF. However, previous studies on malnutrition in PLF were limited through use of a Medicare-only sample and did not consider BMI as a confounding variable. The purpose of the present study was to provide an analysis examining the effect of malnutrition on postoperative outcomes over a comprehensive range of BMI, from underweight to morbidly obese, in adult patients undergoing PLF. A retrospective database study. A total of 12,837 patients undergoing elective PLF were included in this analysis. The number of patients in the all-BMI, underweight, normal BMI, obese and morbidly obese cohorts after the matching process were 1,106, 277, 808, 677 and 449, respectively with successful 3:1 matching versus nonmalnourished patients. Medical and surgical complications within one-year postoperatively were recorded including cardiac complications, hemorrhage and hematoma, instrumentation complications, need for revision fusion, pulmonary complications, sepsis, surgical site complications, thromboembolism and urinary complications. The PearlDiver Mariner database was queried between 2010-2020 to identify patients with CPT codes for PLF. ICD-9 and ICD-10 codes were used to identify PLF patients with malnutrition and a BMI diagnosis code to create an all-BMI cohort. In order to analyze malnutrition patients across the BMI spectrum, PLF patients with malnutrition were additionally placed in one of the following BMI sub-grouped cohorts: underweight (BMI 40). The all-BMI and BMI subgroup cohorts were then matched 1:3 to patients within the same BMI group to nonmalnutrition PLF patients based on age, gender and Charlson Comorbidity Index. Complication rates between study and control groups were calculated using the Pearson Chi-square method. The malnourished all-BMI cohort showed greater odds of instrumentation complications (odds Ratio [OR]; 2.28; p < 0.001), need for revision fusion (OR: 2.04; p < 0.001), pulmonary complications (OR: 1.45; p < 0.001), sepsis (OR: 2.89; p < 0.001), surgical site complications (OR: 1.87; p < 0.001 and urinary complications (OR: 1.41; p < 0.001). Similar increase in risk was observed for all postopera