Impact of body mass index on opioid consumption in lumbar spine fusion surgery

Taryn E Leroy,Andrew S Moon,Marissa Gedman,Jessica P Aidlen,Ashley Rogerson

doi:10.1016/j.xnsj.2021.100060

Abstract

Backgroundin the United States from 1999 to 2000 through 2017–2018, the prevalence of obesity increased from 30.5 to 42.4%, while the prevalence of severe obesity nearly doubled. In lumbar spine surgery, obesity is associated with increased complications, worse perioperative outcomes, and higher costs. The purpose of this study was to examine the association between body mass index (BMI) and opioid consumption in patients undergoing lumbar spine fusion surgery. We hypothesized that obese patients would require more opioids postoperatively. Methodsretrospective review of 306 patients who underwent one- or two-level posterior lumbar interbody fusion surgery between 2016 and 2020. Patients were stratified by BMI as follows: normal weight (18.5–24.9 kg/m2), overweight (25.0–29.9 kg/m2), obese I (30.0–34.9 kg/m2), and obese II–III (≥ 35.0 kg/m2). Patient demographics and preoperative characteristics were compared across BMI cohorts using one-way ANOVA and chi-square analysis. Patients with prior history of opioid use were excluded. Primary outcome measure was postoperative opioid consumption. Secondary outcomes included operative time, length of stay (LOS), discharge destination, and 30-day re-encounter rates. Outcomes were analyzed using multivariable linear regression adjusted for potential confounders. Resultsof 306 total patients, 17.3% were normal weight, 39.9% were overweight, 25.5% were obese I, and 17.3% were obese II–III. Obesity was associated with longer operative times and length of stay (p < 0.001, p = 0.024). For opioid naïve patients, there was no difference in-house opioid consumption when adjusted for kilograms of body mass and LOS (p = 0.083). Classes II–III patients were prescribed more than twice the number of postoperative opioids (p < 0.001) and were on opioids for a longer time postoperatively (p = 0.019). Conclusionobesity is associated with longer operative times, longer LOS, and increased consumption of postoperative opioids. This should be considered when counseling patients preoperatively prior to lumbar spine fusion procedures.

Highlights

Obesity is a public health crisis in the United States, with nearly forty percent of American adults over the age of 20 considered obese [1]
There was no difference in age, sex, preoperative opioid use, depression, procedure type, discharge destination or 30-day re-encounter rates (Table 1)
After excluding patients with a history of opioid use (N = 84), opioid naïve patients were compared across body mass index (BMI) groups

Summary

Introduction

Obesity is a public health crisis in the United States, with nearly forty percent of American adults over the age of 20 considered obese [1]. Obese people are four times more likely to have a pain complaint compared to those who are not obese [13], and the prevalence of low back pain has been shown to have a direct linear correlation with BMI [14]. Both obesity and back pain negatively impact health related quality of life and account for a large proportion of U.S health care expenditures [17,18]

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