122 - Incidence, Predictors and Outcomes of Pulmonary Embolism after Lumbar...

#122 Incidence, Predictors and Outcomes of Pulmonary Embolism after Lumbar Spine Surgery

Epidemiology/Natural History

Poster Presented by: K. Singh

Author(s):

A.J. Marquez-Lara (1)
S.V. Nandyala (1)
S.J. Fineberg (1)
M. Noureldin (1)
K. Singh (1)

(1) Rush University Medical Center, Orthopaedic Surgery, Chicago, IL, United States

Abstract

Introduction: Postoperative pulmonary embolism (PE) is a well-known life-threatening complication following orthopaedic surgery. Despite many advances in prevention and management of this complication, there is limited data on PE following lumbar spinal surgery (LSS). The purpose of this study is to determine the incidence as well as pre- and intraoperative risk factors for PE following LSS.

Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was utilized to identify patients who underwent elective LSS for degenerative pathologies. Patients who developed a PE were compared to unaffected patients. Preoperative patient characteristics (demographics, co-morbidities, pre-operative lab values), surgery and hospital outcomes (e.g., operative time, length of stay, 30-day complication rates, and mortality) were compared between groups. Statistical analysis was performed with SPSS v.20 utilizing independent T-tests and χ2-tests for continuous and categorical variables respectively. P-values ≤ 0.05 were considered statistically significant. Logistic regression was performed to identify predictors for a postoperative PE.

Results: A total of 22,610 LSS procedures were identified between 2006-2011. Postoperative PEs were diagnosed in 79 patients (0.3%) following LSS. Risk factors found to be more prevalent in the affected group included increased age, higher BMI, COPD, hypertension, metastatic cancer, open wound infection and steroid use (p< 0.05). Preoperative mean white blood cell count (WBC) and INR were significantly greater while mean serum albumin was significantly lower in patients who developed a PE after LSS (p< 0.05). A higher proportion of non-ambulatory surgery, ASA class 4 patients, along with a greater operative time was demonstrated in those diagnosed with a PE after LSS (p< 0.0001). Patients with a postoperative PE had a greater length of stay, readmission rate, incidence of deep vein thrombosis (DVT) and mortality (p< 0.0001). Independent predictors for a postoperative PE included obesity (BMI>30kg/m2; OR=1.67), elevated WBC (OR=1.91), and prolonged operative time (OR=1.004). Interestingly, smokers had a significant decrease in risk for developing a postoperative PE (OR=0.15).

Conclusion: The incidence of PE after LSS found in this study was 0.3%. Despite this rare occurrence, those patients who developed a postoperative PE subsequently required a longer hospital stay, had a higher readmission rate and demonstrated a significant increase in mortality. Furthermore, risk factors found to be independent predictors of a PE following LSS included: obesity, elevated WBC and longer operative time. Interestingly, in our study smokers had a decreased risk for developing a postoperative PE, contradicting previous studies that state smoking increases the rates of thromboembolic events. Understanding the incidence and risk factors associated with a PE following LSS, may assist in the development of protocols for prevention, diagnosis and treatment of this potentially fatal complication.