Pre-operative transfusions are associated with numerous post-operative complications in total hip arthroplasty

Predicting 30-Day Venous Thromboembolism Following Total Joint Arthroplasty: Adjusting for Trends in Annual Length of Stay

Background

Venous thromboembolism (VTE) following total hip arthroplasty and total knee arthroplasty (TKA) is linked to immobility, and preoperative prediction remains difficult. We aimed to evaluate whether annual mean length of stay (LOS) is associated with the incidence of VTE and develop a generalizable machine learning model to preoperatively predict the incidence of symptomatic VTE following total hip and TKA using National Surgical Quality Improvement Program.

Methods

Annual incidence of 30-day postoperative VTE, deep vein thrombosis, and pulmonary embolism was calculated over 6 years and tested for trend. Correlation between annual VTE rates and mean LOS was calculated. Predictive models (logistic regression, random forest, and XGBoost) were trained and tested based on year of surgery with different oversampling algorithms used to address data imbalance.

Results

A total of 498,314 patients were included, with 0.88% developing a VTE within 30 days. VTE rates decreased from 1.11% in 2014 to 0.76% in 2019 (P < .001). There was a strong correlation between the yearly incidence of VTE, pulmonary embolism, and deep vein thrombosis and mean LOS (r = 0.96, 0.87, and 0.98, respectively). Univariate analysis demonstrated that TKA, inpatient setting, American Society of Anesthesiologists classification, and various patient comorbidities were significantly associated with VTE. The logistic regression model trained on all data with a balanced loss scoring function performed the best (area under the curve = 0.600).

Conclusions

This study revealed declining VTE rates strongly correlated to decreasing postoperative LOS and identified patient and surgery-specific factors associated with VTE risk. Development of more accurate machine learning models for VTE prediction may improve risk stratification, prevention, and monitoring for arthroplasty patients.

Association Between Preoperative Blood Transfusion and Postoperative Venous Thromboembolism: Review Meta-Analysis

BACKGROUND

Several studies have shown that preoperative blood transfusion is associated with postoperative venous thromboembolism (VTE). In this study, a meta-analysis was performed to explore the relationship between preoperative blood transfusion and postoperative VTE.

METHODS

Published articles were identified through a comprehensive review of PubMed and EMBASE. Data from studies reporting relative risks, odds ratios, or hazard ratios comparing the risk of postoperative VTE among participants who had preoperative blood transfusion versus those without preoperative blood transfusion were analyzed. A random-effect model was used to calculate pooled odds ratios and 95% confident intervals (CIs).

RESULTS

Eight studies, which included 3,504,778 participants, aligned with our inclusion criteria and were included in the meta-analysis. Pooled analysis showed an association between preoperative blood transfusion and postoperative VTE, with an odds ratio of 2.95 (95% CI: 1.65-5.30; I² = 89.1%). In subgroup analyses, the positive association between preoperative blood transfusion and postoperative VTE was still exist in studies with confounders adjustment. Sensitivity analysis by one-study-removed analysis confirmed the robustness of our results.

CONCLUSIONS

Our study indicated that preoperative blood transfusion was associated with higher odds of postoperative VTE. Further large-scale prospective cohort studies are needed to investigate the causality between preoperative blood transfusion and postoperative VTE.

Pre-operative hemoglobin level and use of sedative-hypnotics are independent risk factors for post-operative delirium following total knee arthroplasty

BACKGROUND

Delirium is a well-known complication following surgery, especially with the increasing age of patients undergoing surgery. The increasing demands resulting from a prolonged healthy life expectancy has resulted in more arthroplasties despite their age and existing comorbidities. The purpose of this study is to explore the various risk factors that may contribute to delirium in unilateral and bilateral total knee arthroplasties in the elderly population.

METHODS

170 patients who underwent unilateral or bilateral total knee arthroplasties were analyzed retrospectively for delirium. Age, sex, comorbidities, use of sedative-hypnotics, peri-operative blood loss, pre- and post-operative laboratory blood test results were investigated and analyzed.

RESULTS

The incidence of post-operative delirium was 6.5% (11 out of 170 patients) with a mean age of 79.5 (± 6.9) years, compared to 73.0 (± 9.0) years in the non-delirium group. Higher age, use of sedative-hypnotics, low pre-operative Hb and Ht, low post-operative Hb, Ht and BUN were observed in the delirium group. Multivariate logistic regression analysis identified that the use of sedative-hypnotics and pre-operative Hb level were independent risk factors for post-operative delirium after TKA. The odds ratios for the use of sedative-hypnotics and pre-operative Hb level were 4.6 and 0.53, respectively. Receiver operating characteristic curve analysis showed that pre-operative Hb of less than 11.1 g/dL was a predictor for the development of delirium, with a sensitivity of 54.6% and a specificity of 91.6%.

CONCLUSION

Patients with a pre-operative Hb level of < 11.1 g/dL or those using sedative-hypnotics are associated with post-operative delirium. Peri-operative management and preventative measures are therefore needed to reduce the risks of post-operative delirium in such patients.