Independent Association Between Type of Intraoperative Blood Transfusion and Postoperative Delirium After Complex Spinal Fusion for Adult Deformity Correction

Risk factors of postoperative delirium following spine surgery: A meta-analysis of 50 cohort studies with 1.1 million participants

Objectives

Postoperative delirium (POD) is considered to be a common complication of spine surgery. Although many studies have reported the risk factors associated with POD, the results remain unclear. Therefore, we performed a meta-analysis to identify risk factors for POD among patients following spinal surgery.

Methods

We systematically searched the PubMed, Embase and the Cochrane Library for relevant articles published from 2006 to February 1, 2023 that reported risk factors associated with the incidence of POD among patients undergoing spinal surgery. The Meta-Analysis of Observational Studies in Epidemiology (MOOSE) guidelines were followed, and random effects models were used to estimate pooled odds ratio (OR) estimates with 95 % confidence intervals (CIs) for each factor. The evidence from observational studies was classified according to Egger's P value, total sample size, and heterogeneity between studies.

Results

Of 11,329 citations screened, 50 cohort studies involving 1,182,719 participants met the inclusion criteria. High-quality evidence indicated that POD was associated with hypertension, diabetes mellitus, cardiovascular disease, pulmonary disease, older age (>65 years), patients experiencing substance use disorder (take drug ≥1 month), cerebrovascular disease, kidney disease, neurological disorder, parkinsonism, cervical surgery, surgical site infection, postoperative fever, postoperative urinary tract infection, and admission to the intensive care unit (ICU). Moderate-quality evidence indicated that POD was associated with depression, American Society of Anesthesiologists (ASA) fitness grade (>II), blood transfusion, abnormal potassium, electrolyte disorder, length of stay, inability to ambulate and intravenous fluid volume.

Conclusions

Conspicuous risk factors for POD were mainly patient- and surgery-related. These findings help clinicians identify high-risk patients with POD following spinal surgery and recognize the importance of early intervention.

Quantile regression-based prediction of intraoperative blood loss in patients with spinal metastases: model development and validation

PURPOSE

To develop and evaluate a quantile regression-based blood loss prediction model for open surgery of spinal metastases.

METHODS

This was a multicenter retrospective cohort study. Over a 11-year period, patients underwent open surgery for spinal metastases at 6 different institutions were reviewed. The outcome measure is intraoperative blood loss (in mL). The effects of baseline, histology of primary tumor and surgical procedure on blood loss were evaluated by univariate and multivariate analysis to determine the predictors. Multivariate ordinary least squares (OLS) regression and 0.75 quantile regression were used to establish two prediction models. The performance of the two models was evaluated in the training set and the test set, respectively.

RESULTS

528 patients were included in this study. Mean age was 57.6 ± 11.2 years, with a range of 20-86 years. Mean blood loss was 1280.1 ± 1181.6 mL, with a range of 10 ~ 10,000 mL. Body mass index (BMI), tumor vascularization, surgical site, surgical extent, total en bloc spondylectomy and microwave ablation use were significant predictors of intraoperative blood loss. Hypervascular tumor, higher BMI, and broader surgical extent were related with massive blood loss. Microwave ablation is more beneficial in surgery with substantial blood loss. Compared to the OLS regression model, the 0.75 quantile regression model may decrease blood loss underestimate.

CONCLUSION

In this study, we developed and evaluated a prediction model for blood loss in open surgery for spinal metastases based on 0.75 quantile regression, which may minimize blood loss underestimate.

An Artificial Neural Network Model for the Prediction of Perioperative Blood Transfusion in Adult Spinal Deformity Surgery

Prediction of blood transfusion after adult spinal deformity (ASD) surgery can identify at-risk patients and potentially reduce its utilization and the complications associated with it. The use of artificial neural networks (ANNs) offers the potential for high predictive capability. A total of 1173 patients who underwent surgery for ASD were identified in the 2017–2019 NSQIP databases. The data were split into 70% training and 30% testing cohorts. Eighteen patient and operative variables were used. The outcome variable was receiving RBC transfusion intraoperatively or within 72 h after surgery. The model was assessed by its sensitivity, positive predictive value, F1-score, accuracy (ACC), and area under the curve (AUROC). Average patient age was 56 years and 63% were female. Pelvic fixation was performed in 21.3% of patients and three-column osteotomies in 19.5% of cases. The transfusion rate was 50.0% (586/1173 patients). The best model showed an overall ACC of 81% and 77% on the training and testing data, respectively. On the testing data, the sensitivity was 80%, the positive predictive value 76%, and the F1-score was 78%. The AUROC was 0.84. ANNs may allow the identification of at-risk patients, potentially decrease the risk of transfusion via strategic planning, and improve resource allocation.

A clinical calculator for predicting intraoperative blood loss and transfusion risk in spine tumor patients

BACKGROUND CONTEXT

Surgery for vertebral column tumors is commonly associated with intraoperative blood loss (IOBL) exceeding 2 liters and the need for transfusion of allogeneic blood products. Transfusion of allogeneic blood, while necessary, is not benign, and has been associated with increased rates of wound complication, venous thromboembolism, delirium, and death.

PURPOSE

To develop a prediction tool capable of predicting IOBL and risk of requiring allogeneic transfusion in patients undergoing surgery for vertebral column tumors.

STUDY DESIGN/SETTING

Retrospective, single-center study.

PATIENT SAMPLE

Consecutive series of 274 patients undergoing 350 unique operations for primary or metastatic spinal column tumors over a 46-month period at a comprehensive cancer center OUTCOME MEASURES: IOBL (in mL), use of intraoperative blood products, and intraoperative blood products transfused.

METHODS

We identified IOBL and transfusions, along with demographic data, preoperative laboratory data, and surgical procedures performed. Independent predictors of IOBL and transfusion risk were identified using multivariable regression.

RESULTS

Mean age at surgery was 57.0±13.6 years, 53.1% were male, and 67.1% were treated for metastatic lesions. Independent predictors of IOBL included en bloc resection (p<.001), surgical invasiveness (β=25.43 per point; p<0.001), and preoperative albumin (β=-244.86 per g/dL; p=0.011). Predictors of transfusion risk included preoperative hematocrit (odds ratio [OR]=0.88 per %; 95% confidence interval [CI, 0.84, 0.93]; p<0.001), preoperative MCHgb (OR=0.88 per pg; 95% CI [0.78, 1.00]; p=0.048), preoperative red cell distribution width (OR=1.32 per %; 95% CI [1.13, 1.55]; p<0.001), en bloc resection (OR=3.17; 95%CI [1.33, 7.54]; p=0.009), and surgical invasiveness (OR=1.08 per point; [1.06; 1.11]; p<0.001). The transfusion model showed a good fit of the data with an optimism-corrected area under the curve of 0.819. A freely available, web-based calculator was developed for the transfusion risk model (https://jhuspine3.shinyapps.io/TRUST/).

CONCLUSIONS

Here we present the first clinical calculator for intraoperative blood loss and transfusion risk in patients being treated for primary or metastatic vertebral column tumors. Surgical invasiveness and preoperative microcytic anemia most strongly predict transfusion risk. The resultant calculators may prove clinically useful for surgeons counseling patients about their individual risk of requiring allogeneic transfusion.

Neuroanesthesiology Update

This review summarizes the literature published in 2020 that is relevant to the perioperative care of neurosurgical patients and patients with neurological diseases as well as critically ill patients with neurological diseases. Broad topics include general perioperative neuroscientific considerations, stroke, traumatic brain injury, monitoring, anesthetic neurotoxicity, and perioperative disorders of cognitive function.