Preoperative hypoalbuminemia and dialysis increase morbidity/mortality after spine surgery for primary pyogenic spinal infections (ACS-NSQIP Study)

Elevated Serum Alkaline Phosphatase is an Independent Predictor of Complications After Lumbar Spinal Fusion

BACKGROUND

Alkaline phosphatase (ALP) is an enzyme which has been proven useful as a biomarker for bone turnover and inflammation. We hypothesized that high serum ALP levels are associated with increased complication rates following lumbar spinal fusion.

METHODS

Lumbar spinal fusion procedures from 2005 to 2019 were queried from the National Surgical Quality Improvement Program (NSQIP) database. Serum alkaline phosphatase levels were stratified into low <44 IU/L, normal 44-147 IU/L, and high >147 IU/L. A risk-adjusted multivariate logistic regression was used to analyze ALP as an independent risk factor for complications.

RESULTS

A total of 16,441 patients who underwent lumbar fusion procedures were included. Adjusted multivariate logistic regression analysis demonstrated that patients with a high serum ALP level had a significantly increased risk for developing septic shock (OR 4.68, 95% CI 1.83-11.97), pneumonia (OR 2.89, 95% CI 1.59-5.25), requiring a transfusion (OR 2.09, 95% CI 1.68-2.59), reoperation within 30 days (OR 1.68, 95% CI 1.12-2.52), readmission within 30 days (OR 1.60, 95% CI 1.16-2.21), increased length of stay (OR 1.87, 95% CI 1.49-2.36), and nonhome discharge (OR 2.18, 95% CI 1.80-2.66).

CONCLUSIONS

Elevated serum ALP in patients undergoing lumbar fusion procedures is associated with increased risk for multiple in-hospital complications as well as higher rates of readmission and reoperation.

Risk Factors for Surgical Site Infections After Single-Level Anterior Lumbar Interbody Fusion

Abstract Background: Anterior lumbar interbody fusion (ALIF) has become an increasingly popular and effective treatment modality for various conditions of the lumbar spine. However, complications after this procedure can be costly. Surgical site infections (SSIs) are one of these types of complications. The present study identifies independent risk factors for SSI after single-level ALIF to identify high-risk patients better. Patients and Methods: The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database was queried to identify single-level ALIF patients from 2005 to 2016. Multilevel fusions and non-anterior approach procedures were excluded. Mann-Pearson χ² tests analyzed categorical variables, whereas one-way analysis of variance (ANOVA) and independent t-tests analyzed differences in mean values of continuous variables. Risk factors for SSI were identified via a multivariable logistic regression model. A receiver operating characteristic (ROC) curve was generated utilizing the predicted probabilities. Results: A total of 10,017 patients met inclusion criteria; 80 (0.80%) had developed SSI and 9,937 (99.20%) had not. On multivariable logistic regression models, class 3 obesity (p = 0.014), dialysis (p = 0.025), long-term steroid use (p = 0.010), and wound classification 4 (dirty/infected) (p = 0.002) all independently increased the risk for SSI in single-level ALIF. The area under the receiver operating characteristic curve (AUROC; C-statistic) was 0.728 (p < 0.001), indicating relatively strong reliability of the final model. Conclusions: Several independent risk factors including obesity, dialysis, long-term steroid use, and dirty wound classification all increased risk for SSI after single-level ALIF. By identifying these high-risk patients, surgeons and patients can have more informed pre-operative discussions. In addition, identifying and optimizing these patients prior to operative intervention may help to minimize infection risk.

Association of Frailty and Preoperative Hypoalbuminemia with the Risk of Complications, Readmission, and Mortality After Spine Surgery

BACKGROUND

Frailty status and hypoalbuminemia have been associated with higher rates of complications after spine surgery. However, the combination of both conditions has not been fully analyzed. The objective of this study was to assess the effect of frailty and hypoalbuminemia on the risk of complications after spine surgery.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2009 to 2019 was used. Frailty status was calculated using the modified 5-item frailty index (mFI-5). Patients were classified into nonfrail (mFI = 0), pre-frail (mFI = 1), and frail (mFI ≥2) groups and also based on albumin levels into normal (≥3.5 g/dL) and hypoalbuminemia groups (<3.5 g/dL). The latter group was also subclassified into mild and severe hypoalbuminemia groups. Multivariable analysis was used. A Spearman ρ correlation between albuminemia and mFI-5 was also performed.

RESULTS

A total of 69,519 patients (36,705 men [52.8%] and 32,814 women [47.2%]) with a mean age of 61.0 ± 13.2 years were included. Patients were classified as nonfrail (n = 24,897), pre-frail (n = 28,897), and frail groups (n = 15,725). Hypoalbuminemia was significantly higher in the frail group (11.4%) compared with the nonfrail group (4.3%). An inverse correlation was observed between albumin levels and frailty status (ρ = -0.139; P < 0.0001). Frail patients with severe hypoalbuminemia had significantly higher risk of complications (odds ratio [OR], 5.0), reoperation (OR, 3.3), readmission (OR, 3.1), and mortality (OR, 31.8) compared with patients without hypoalbuminemia.

CONCLUSIONS

The combination of frailty and hypoalbuminemia significantly increases the risk of complications after spine surgery. The prevalence of hypoalbuminemia in the frailty group was significantly higher than in nonfrail patients (11.4% vs. 4.3%). Both conditions should be evaluated preoperatively.

Preoperative Serum Albumin Level Predicts Length of Stay and Perioperative Adverse Events Following Vertebral Corpectomy and Posterior Stabilization for Metastatic Spine Disease

STUDY DESIGN

Retrospective review of a prospectively collected national database.

OBJECTIVES

To determine the association between preoperative serum albumin levels and perioperative adverse events (AEs) following vertebral corpectomy and posterior stabilization for metastatic spine disease.

METHODS

The 2010 to 2019 American College of Surgeons' National Surgical Quality Improvement (ACS-NSQIP) database was used to identify all patients undergoing vertebral corpectomy and posterior stabilization for metastatic spine disease. Receiver operative characteristic (ROC) curve analysis was used to determine preoperative serum albumin cut-off values for predicting perioperative AEs. Low preoperative serum albumin was defined as serum albumin below this cut-off value.

RESULTS

A total of 301 patients were included in the study. ROC curve analysis demonstrated serum albumin < 3.25 g/dL as a cut-off value for predicting perioperative AEs. The low serum albumin group had a higher overall perioperative AEs (P = .041), longer post-operative LOS (P < .001), higher 30-day reoperation rate (P = .014), and a higher in-hospital mortality rate (P = .046). Multivariate analysis demonstrated that low preoperative serum albumin was associated with higher perioperative AEs.

CONCLUSIONS

Low serum albumin level is associated with higher perioperative AEs, longer postoperative LOS, and higher rates of 30-day reoperation and in-hospital mortality among patients undergoing vertebral corpectomy and posterior stabilization for metastatic spine disease. Strategies to improve preoperative nutritional status in patients undergoing this procedure may improve these perioperative outcome measures within this surgical population.

LEVEL OF EVIDENCE

III.

The impact of stratified hypoalbuminemia and dialysis on morbidity/mortality after posterior spinal fusion surgery: An ACS-NSQIP study

Background:

Preoperative optimization in patients undergoing posterior spinal fusion is essential to limit the number and severity of postoperative complications. Here, we, additionally, evaluated the impact of hypoalbuminemia on morbidity and mortality after posterior spinal fusion surgery.

Methods:

This retrospective analysis was performed using data from a prospective multicentric database (ACSNSQIP:2015–2020) regarding patients undergoing posterior spinal fusions. Factors studied included; baseline demographics and 30-day postoperative complications (i.e., reoperations, readmissions, and mortality rates).

Results:

There were 6805 patients who met the inclusion criteria. They averaged 62 years of age and had an average BMI of 30.2. Within the 30-day postoperative period, 634 (9.3%) sustained complications; 467 (6.9%) were readmitted, 263 (3.9%) required reoperations, and 37 (0.5%) expired. Although multiple preoperative risk factors were analyzed, hypoalbuminemia, severe hypoalbuminemia, and dialysis were the strongest independent risk factors associated with complications (i.e., reoperations, readmissions, and mortality).

Conclusion:

Hypoalbuminemia, severe hypoalbuminemia, and dialysis were significant predictors for morbidity and mortality after posterior spinal fusion surgery.