Underweight patients are an often under looked “At risk” population after undergoing posterior cervical spine surgery

Abstract

Background: Body Mass Index (BMI) is a weight-for-height metric that is used to quantify tissue mass and weight levels. Past studies have mainly focused on the association of high BMI on spine surgery outcomes and shown variable conclusions. Prior results may have varied due to insufficient power or inconsistent categorical separation of BMI groups (e.g. underweight, overweight, or obese). Additionally, few studies have considered outcomes of patients with low BMI. The aim of the current study was to analyze patients along the entirety of the BMI spectrum and to establish specific granular BMI categories for which patients become at risk for complication and mortality following posterior cervical spine surgery.Methods: Patients undergoing elective posterior cervical spine surgery were abstracted from the 2005-2016 National Surgical Quality Improvement Program (NSQIP) databases. Patients were aggregated into pre-established WHO BMI categories and adverse outcomes were normalized to average risk of normal-weight subjects (BMI 18.5-24.9 kg/m 2 ). Risk-adjusted multivariate regressions were performed controlling for patient demographics and overall health.Results: A total of 16,806 patients met inclusion criteria. Odds for adverse events for underweight patients (BMI < 18.5 kg/m 2 ) were the highest among any category of patients along the BMI spectrum. These patients experienced increased odds of any adverse event (Odds Ratio (OR) = 1.67, p = 0.008, major adverse events (OR = 2.08, p = 0.001), post-operative infection (OR = 1.95, p = 0.002), and reoperation (OR = 1.84, p = 0.020). Interestingly, none of the overweight or obese categories were found to be correlated with increased risk of adverse event categories other than super-morbidly obese patients (BMI > 50.0 kg/m 2 ) for post-operative infection (OR = 1.54, p = 0.041). Conclusions:The current study found underweight patients to have the highest risk of adverse events after posterior cervical spine surgery. Increased pre-surgical planning and resource allocation for this population should be considered by physicians and healthcare systems, as is often already done for patients on the other end of the BMI spectrum.

Body Mass Index and Risk of Complications After Posterior Lumbar Spine Fusion: A Matched Cohort Analysis Investigating Underweight and Obese Patients

“…12–16 Prior investigations have shown that underweight patients were at risk of adverse events after both anterior and posterior cervical spine surgeries. 17,18 Similarly, a previous study also found that underweight patients had worse surgical outcomes after lumbar disk herniation. 19 Consequently, underweight patients may also have increased complication rates after lumbar fusion surgery.…”

Anterior Cervical Discectomy and Fusion Outcomes in Patients With and Without Bariatric Surgery—Weight Loss Does Make a Difference

“…Anterior cervical discectomy and fusion (ACDF) is one of the most commonly performed spinal operations in the United States 1–3. Obesity, which is increasing in the population in general,4,5 has been identified as a potentially modifiable risk factor for adverse events after such procedures 6–11. Following ACDF, obese patients may be at greater risk of intraoperative adverse events8,9,12 and postoperative neurological,8,13 respiratory,8,13 hematologic adverse events,8–10 and dysphagia8,9 compared with non-obese patients.…”

Letter: A Pathway to Safe Spine Surgery in Underweight Frail Patients: The Revised Risk Analysis Index Displays Remarkable Discrimination for 30-Day Postoperative Mortality and Nonhome Discharge

“…1 Therefore, identifying risk factors for unfavorable postoperative outcomes is crucial for improving patient-centered decision-making, coordinating perioperative care, and optimizing quality improvement efforts. 2,3 Underweight frail patients may encounter challenges with spine surgery and postoperative recovery. 2,4 Their increased risk of unfavorable postoperative outcomes may be attributed to reduced system-wide resilience, potentially impeding wound healing and recovery.…”

“…2,4 These patients have increased risk of developing major and lifethreatening complications, 30-day postoperative mortality, and nonhome discharge (NHD). 2,4 Frailty is defined as a multimodal, age-related decline in physiological reserve, resulting in a decreased ability to cope with imposed stressors. 5,6 A variety of clinical and biochemical variables can be used to assess frailty by examining various frailty domains and offering a comprehensive insight into a patient's overall health status.…”