Postoperative Narcotic Consumption following a Minimally Invasive Lumbar Decompression Surgery in Medicare Beneficiaries

Presented at SMISS Annual Forum 2014
By Islam Elboghdady
With Kern Singh MD, Sreeharsha Nandyala BA, Alejandro Marquez-Lara MD, Eric Sundberg MD, Hamid Hassanzadeh MD, Anton Jorgensen MD, Khaled Aboushaala MD, Junyoung Ahn ,

Disclosures: Islam Elboghdady None Kern Singh MD A; CSRS Resident Grant. B; DePuy, Zimmer, Stryker, CSRS, ISASS, AAOS, SRS, Vertebral Column - ISASS. D; Avaz Surgical, LLC, Vital 5, LLC. F; Zimmer, Stryker, Pioneer, Lippincott Williams & Wilkins, Th, Sreeharsha Nandyala BA None, Alejandro Marquez-Lara MD None, Eric Sundberg MD None, Hamid Hassanzadeh MD None, Anton Jorgensen MD None, Khaled Aboushaala MD None, Junyoung Ahn None,

Medicare beneficiaries are comprised of older and more comorbid patients that may be at a greater risk of narcotic related adverse events in the immediate postoperative period. As such, these patients are likely to benefit from less invasive techniques to minimize postoperative narcotic consumption.

To characterize the differences in postoperative narcotic consumption between Medicare (MC) patients and non-MC patients following a minimally invasive (MIS) lumbar decompression (LD) procedure.

335 patients who underwent a primary one- or two-level MIS LD procedure (laminectomy or diskectomy) for degenerative spinal pathology between 2006-2013 were retrospectively analyzed. Patients were stratified based upon the primary payor status (MC vs non-MC) and assessed with regards to patient demographics, comorbidity burden, smoking status, length of hospitalization, peri-operative outcomes, and daily (postoperative day (POD)) in-hospital oral morphine equivalent (OME) dosing. Statistical analysis was performed with a chi-squared test for categorical variables and Student-Test for continuous variables. OME means were compared utilizing non-parametric analysis to adjust for skewedness. A p-value of <0.05 denoted statistical significance.

Of the 335 LD procedures, 43 (12.8%) were performed on MC beneficiaries. MC patients were older (68.2±12.1 vs 42.8±11.9 years old; p<0.05), and demonstrated a greater comorbidity burden (CCI: 4.47±1.79 vs 1.45±1.61; p<0.05) than non-MC patients. The MC cohort more often underwent a two-level LD (55.8% vs 17.8%, p<0.05), and incurred a longer operative time (56.9±16.4 vs 41.9±19.2 min, p<0.05), higher rates of peri-operative complications (durotomy and urinary retention), and longer hospitalizations (35.9±29.7 vs 14.6±15.2 hours, p<0.05) compared to the non-MC cohort. MC patients demonstrated lower cumulative narcotic consumption in all discharge days, however these differences were not statistically significant (POD 0: 15.6±12.9 vs 18.4±11.6mg, p=0.26; POD 1: 61.6±47.0 vs 98.2±213.7 mg, p=0.20; POD 2: 41.5±30.5 vs 99.9±105.6 mg, p=0.14; POD 3+: 116.1±98.8 vs 121.6±97.2 mg, p=0.69).

Despite more extensive surgery and worsened peri-operative outcomes, MC patients did not demonstrate significant differences in cumulative narcotic consumption between MC and non-MC patients following a MIS LD procedure. Furthermore, MC patients demonstrated a slightly lower cumulative OME dose despite a longer hospitalization. These findings suggest that the greater rate of urinary retention incurred by MC patients may be associated with greater age and comorbidity rather than excessive narcotic dosing.