Factors that influence blood loss and need for transfusion following total knee arthroplasty

Prevalence of Blood Transfusion and Factors Influencing Blood Loss Following Primary Total Knee Replacement Surgery

Introduction

Total knee replacement (TKR) is a highly effective treatment for end-stage knee osteoarthritis and has been proven to have excellent results in relieving pain as well as improving mobility of the patient. Although becoming more increasingly performed, it is still associated with considerable perioperative blood loss requiring allogenic blood transfusion. Allogenic blood transfusion (ABT) can be lifesaving in certain clinical situations but also comes with their own risks and side effects. The reported incidence of ABT and blood loss following TKR surgery varies widely in the literature. The objectives of this study were to look at the prevalence of ABT, factors leading to transfusion as well as increase in blood loss.

Material and Methods

A cross-sectional retrospective study was conducted involving 296 adult patients who underwent elective primary unilateral TKR surgery from January 2015 until December 2019 at Hospital Melaka. Medical records of these patients were reviewed, and relevant data were extracted for final analysis. Incidence of ABT, demographic data, use of antiplatelet/anticoagulant, tourniquet time, types of general anaesthesia, and pre- and post-operative haemoglobin count were recorded. These factors were analysed to look at the association with ABT as well as increase in blood loss.

Results

Prevalence of ABT following primary unilateral TKR surgery were found to be 4.39% (95% confidence interval 2.04, 6.74). Pre-operative haemoglobin value was found to be the only significant variable associated with blood transfusion [P<0.001; Odds ratio (OR) = 0.35; 95% Confidence interval (CI) 0.22, 0.54]. Meanwhile, prolonged tourniquet time of >120 minutes was the only significant variable towards an increase in blood loss. Participants with tourniquet time >120 minutes has 2.67 times the odds to have blood loss >2 g/dL compared to participants with tourniquet time of less or equal to 120 minutes (95% CI=1.54, 4.64).

Conclusion

The prevalence of ABT following primary unilateral TKR was lower in our centre compared to other reported studies. Pre-operative optimisation of anaemic patients with haematinics will help surgeons reduce the need for ABT.

Prediction of transfusion risk after total knee arthroplasty: use of a machine learning algorithm

INTRODUCTION

Total knee arthroplasty (TKA) carries a significant hemorrhagic risk, with a non-negligible rate of postoperative transfusions. The blood-sparing strategy has evolved to reduce blood loss after TKA by identifying the patient's risk factors preoperatively. In practice, a blood count is often performed postoperatively but rarely altering the patient's subsequent management. This study aimed to identify the preoperative variables associated with hemorrhagic risk, enabling the creation of a machine-learning model predictive of transfusion risk after total knee arthroplasty and the need for a complete blood count.

HYPOTHESIS

Based on preoperative data, a powerful machine learning predictive model can be constructed to estimate the risk of transfusion after total knee arthroplasty.

MATERIAL AND METHODS

This retrospective single-centre study included 774 total knee arthroplasties (TKA) operated between January 2020 and March 2023. Twenty-five preoperative variables were integrated into the machine learning model and filtered by a recursive feature elimination algorithm. The most predictive variables were selected and used to construct a gradient-boosting machine algorithm to define the overall postoperative transfusion risk model. Two groups were formed of patients transfused and not transfused after TKA. Odds ratios were determined, and the area under the curve evaluated the model's performance.

RESULTS

Of the 774 TKA surgery patients, 100 were transfused postoperatively (12.9%). The machine learning predictive model included five variables: age, body mass index, tranexamic acid administration, preoperative hemoglobin level, and platelet count. The overall performance was good with an area under the curve of 0.97 [95% CI 0.921-1], sensitivity of 94.4% [95% CI 91.2-97.6], and specificity of 85.4% [95% CI 80.6-90.2]. The tool developed to assess the risk of blood transfusion after TKA is available at https://arthrorisk.com.

CONCLUSION

The risk of postoperative transfusion after total knee arthroplasty can be predicted by a model that identifies patients at low, moderate, or high risk based on five preoperative variables. This machine learning tool is available on a web platform that is accessible to all, easy to use, and has a high prediction performance. The model aims to limit the need for routine check-ups, depending on the risk presented by the patient.

LEVEL OF EVIDENCE

II; diagnostic study.

Total Knee Replacement Among Elderly: The Role of Tranexamic Acid

Background Tranexamic acid (TXA) administration in total knee replacement (TKR) surgery has been shown to reduce blood loss and transfusion requirements. However, its efficacy and safety in elderly patients undergoing arthroplasty remain under investigation. This study aimed to assess the impact of TXA on blood loss and post-operative outcomes in TKR patients among a local elderly population. Methodology A prospective descriptive-analytical hospital-based randomized study was conducted, involving 79 TKR patients who received TXA. Demographic data, comorbidities, pre- and post-operative hemoglobin levels, length of hospital stay, transfusion requirements, and post-operative complications were recorded. Statistical analysis was performed using SPSS (IBM Corp., Armonk, NY), including descriptive analysis and comparative tests. Results The mean drop in hemoglobin levels post-operatively was -1.55 g/dL (SD = 0.94). The majority of patients (78, 98.7%) did not require packed red blood cell transfusions post-operatively, and complications were minimal (1, 1.3%). The length of hospital stay was relatively short (mean = 4.84 days). Comparison with existing literature revealed TXA's effectiveness in reducing blood loss compared to studies without TXA administration. Conclusion TXA administration in TKR surgery effectively reduced blood loss, transfusion requirements, and post-operative complications, supporting its use as a standard adjunctive therapy. These findings emphasize the importance of TXA in optimizing patient outcomes and minimizing surgical complications in TKR patients. Limitations of the study include the relatively small sample size and the exclusion of patients with certain comorbidities, which may limit the generalizability of the findings. Further research is warranted to validate these findings in larger patient cohorts and explore long-term effects.

Risk factor analysis and establishment of a nomogram model to predict blood loss during total knee arthroplasty

PURPOSE

The risk factors for excessive blood loss and transfusion during total knee arthroplasty (TKA) remain unclear. The present study aimed to determine the risk factors for excessive blood loss and establish a predictive model for postoperative blood transfusion.

METHODS

This retrospective study included 329 patients received TKA, who were randomly assigned to a training set (n = 229) or a test set (n = 100). Univariate and multivariate linear regression analyses were used to determine risk factors for excessive blood loss. Univariate and multivariate logistic regression analyses were used to determine risk factors for blood transfusion. R software was used to establish the prediction model. The accuracy and stability of the models were evaluated using calibration curves, consistency indices, and receiver operating characteristic (ROC) curve analysis.

RESULTS

Risk factors for excessive blood loss included timing of using a tourniquet, the use of drainage, preoperative ESR, fibrinogen, HCT, ALB, and free fatty acid levels. Predictors in the nomogram included timing of using a tourniquet, the use of drainage, the use of TXA, preoperative ESR, HCT, and albumin levels. The area under the ROC curve was 0.855 (95% CI, 0.800 to 0.910) for the training set and 0.824 (95% CI, 0.740 to 0.909) for the test set. The consistency index values for the training and test sets were 0.855 and 0.824, respectively.

CONCLUSIONS

Risk factors for excessive blood loss during and after TKA were determined, and a satisfactory and reliable nomogram model was designed to predict the risk for postoperative blood transfusion.

Cardiac interventions on total knee arthroplasty: a national inpatient sample-based analysis

BACKGROUND

Comorbid cardiovascular diseases have been associated with poor outcomes in total knee arthroplasty (TKA); however, our understanding of TKA with prior cardiac treatment procedures has largely been undocumented. In this study, we examined TKA patients who had undergone different cardiac interventions that addressed their condition. The purpose was to characterize and compare outcomes for a growing patient population not yet analyzed.

MATERIALS AND METHODS

The 2016-2019 Nationwide Inpatient Sample database was queried for 558,256 patients who had TKA (ICD-10CM). Backgrounds significant for pacemaker [PM] (n = 8025), coronary artery bypass [CABG] (n = 12,683), heart valve surgery [HV] (n = 4125), or coronary stent [CS] (n = 19,483) were compared against those without, across demographics, admission information, and various complications.

RESULTS

Cardiac interventions were associated with increased age, male gender, length of stay, and cost of care. CABG, and Stent groups had more diabetics, but HV had significantly fewer (p = 0.008). PM and HV had significantly less tobacco use and, in addition to CABG, less obesity. Postoperatively, mortality was elevated in the PM [Odds ratio (OR) 2.89, p = 0.008], CABG (OR 2.53, p = 0.006) and CS group (OR 1.94, p = 0.018), but not HV. Myocardial infarctions were elevated in the CABG (OR 3.874) and CS group (OR 5.11) (p < 0.001). PM, HV, and CS had increased odds of periprosthetic fracture by 2.15-fold (p < 0.001), 2.09-fold (p < 0.001), 1.29-fold (p = 0.011) respectively. HV saw increased periprosthetic mechanical complications (OR 1.48, p = 0.006). CABG increased the odds of deep surgical site infection 14.23-fold and CS 9.22-fold (p < 0.001). Postoperative pneumonia was increased in PM, CABG, and CS groups (OR 2.15,), (OR 2.21,), (OR 1.64,) (p < 0.001).

CONCLUSIONS

Patients who have undergone cardiac intervention are generally at risk for adverse stays. Furthermore, risk factors and complications vary between the groups. Our analysis emphasizes the importance of individualized medical care and as a basis for electing and informing patients for TKA.

Cardiovascular Disease in Total Knee Arthroplasty: An Analysis of Hospital Outcomes, Complications, and Mortality

Background

Cardiovascular comorbidities have been identified as a significant risk factor for adverse outcomes following surgery. The purpose of this study was to investigate its prevalence and impact on postoperative outcomes, hospital metrics, and mortality in patients undergoing total knee arthroplasty (TKA). Our hypothesis was that patients with cardiovascular comorbidities would have worse outcomes, greater postoperative complication rates, and increased mortality compared to patients without cardiovascular disease.

Methods

In this retrospective study, data from the National Inpatient Sample database from 2011 to 2020 were queried for patients who underwent TKA with preexisting cardiac comorbidities, including congestive heart failure (CHF), coronary artery disease (CAD), valvular dysfunction, and arrhythmia. Multivariate logistic regression analyses compared hospital metrics (length of stay, costs, and adverse discharge disposition), postoperative complications, and mortality rates while adjusting for demographic and clinical variables. All statistical analyses were performed using R studio 4.2.2 and Stata MP 17 and 18 with Python package.

Results

A total of 385,585 patients were identified. Those with preexisting CHF, CAD, valvular dysfunction, or arrhythmias were found to be older and at higher risk of adverse outcomes, including prolonged length of stay, increased hospital charges, and increased mortality (p < 0.001). Additionally, all preexisting cardiac diagnoses led to an increased risk of postoperative myocardial infarction, acute kidney injury (AKI), and need for transfusion (p < 0.001). The presence of valvular dysfunction, arrhythmia, or CHF was associated with an increased risk of thromboembolic events (p < 0.001). The presence of CAD and valvular dysfunction was associated with an increased risk of urologic infection (p < 0.001).

Conclusions

This study demonstrated that CHF, CAD, valvular dysfunction, and arrhythmia are prevalent among TKA patients and associated with worse hospital metrics, higher risk of perioperative complications, and increased mortality. As our use of TKA rises, a lower threshold for preoperative cardiology referral in older individuals and early preoperative counseling/intervention in those with known cardiac disease may be necessary to reduce adverse outcomes.

Clinical Outcomes and Experience of a Multiyear Consecutive Case Series of Total Knee Arthroplasty Procedures Conducted with a Bipolar Sealer System for Hemostasis

Maximizing hemostasis during total knee replacement procedures remains a key challenge in current practice. Bipolar sealer technology achieves intraoperative hemostasis through tissue sealing and coagulation with adjustable radio frequency energy and a saline-irrigated tip. Optimal surgical site hemostasis is important to avoid potential complications such as hemarthrosis, wound drainage, increased pain, delayed discharge, and readmissions. The aim of this study is to evaluate the safety and effectiveness of the bipolar sealer device in primary knee replacement in the largest consecutive series to date. A consecutive, treatment-control series of subjects who underwent a primary total knee arthroplasty (TKA) utilizing a bipolar sealer for hemostasis, one subgroup with concomitant tranexamic acid (TXA) administration (n = 1599) and one subgroup without TXA administration (n = 3582), compared with a control group of primary TKA under tourniquet only (n = 667). Statistical analyses were performed through two-tailed unpaired t-tests. There was less total postoperative drain output and a lower overall transfusion rate in the bipolar sealer group (807ml ± 428) (2.5%) than the tourniquet only group (1290 ± 658, p = 0.001) (8.4%, p = 0.0001), respectively. Drainage output in bipolar sealer + TXA (450 ± 297 ml) was lower than the other two groups (bipolar sealer 807 ± 428 mL, p = 0.0001; tourniquet only 1290 ± 658 ml, p = 0.0001). The bipolar sealer group had a higher hematocrit at postoperative day 1 (POD1) (bipolar sealer: 33.1 ± 4.3 cc, tourniquet only: 32.5 ± 4.3 cc, p = 0.001) and at discharge (POD2, bipolar sealer: 31.5 ± 3.7 cc, tourniquet only: 30.2 ± 3.9 cc, p = 0.0001). There were zero reported serious adverse events related to hemostasis management in any group. The bipolar sealer system is a safe and effective instrument to achieve intraoperative hemostasis during primary TKA. The bipolar sealer group required significantly fewer postoperative blood product transfusions and maintained a higher hematocrit concentration at the time of discharge compared with subjects treated solely with tourniquet mediated hemostasis. Addition of TXA to local hemostasis methods may further reduce blood loss and transfusion requirements. LEVEL OF EVIDENCE:  This is a Level III study.

Optimal Release Timing of Drain Clamping to Reduce Postoperative Bleeding after Total Knee Arthroplasty with Intraarticular Injection of Tranexamic Acid

Background and Objectives: Intraarticular injection of tranexamic acid (IA-TXA) plus drain-clamping is a preferred method of reducing bleeding after total knee arthroplasty (TKA). However, no consensus has been reached regarding the timing of the clamping. The purpose of this study was to determine the optimum duration of drain-clamping after TKA with IA-TXA. Materials and Methods: We retrospectively reviewed 151 patients that underwent unilateral TKA with IA-TXA plus drain-clamping for 30 min, 2 h, or 3 h. The total drained volume was reviewed as the primary outcome, and hematocrit (Hct) reductions, estimated blood loss (EBL), transfusion rates, and wound complications were reviewed as secondary outcomes. Results: The mean total drained volume, Hct reduction, and EBL were significantly less in the 3 h group than in the 30 min group. Between the 2 h and 3 h groups, there was no statistical difference in the mean total drained volume, Hct reduction, or EBL. The proportion of patients who drained lesser than 300 mL was high in the 3 h group. No significant intergroup difference was observed for transfusion volume, transfusion rate, and wound related complications. Conclusions: In comparison of the IA-TXA plus drain-clamping after TKA, there was no difference in EBL between the 2 h group and the 3 h group, but the amount of drainage volume was small in the 3 h group.

The effects of a new protocol on blood loss in total knee arthroplasty

The aim of study was to evaluate the efficacy of blood loss prevention with Tranexamic acid in patients undergoing total knee arthroplasty (TKA). The Authors defined a new protocol that foresees the use of Tranexamic acid both pre-intra and post-operatively. Seventy patients indicated for TKA were enrolled. Thirty-five patients (control group) followed standard protocol without Tranexamic acid and the other 35 patients (study group) followed standard protocol with Tranexamic acid. We analyzed the values of hemoglobin (Hb), hematocrit (HCT) and red blood cells (RBCs) both pre-operatively (T0) and post-operatively: immediately after surgery (T1), at one day (T2) and three days post-op (T3). We observed statistical differences at T0 and T3 regarding the Hb, HT and RBCs value between the two groups. Moreover, 11.4% in the study and 28.5% in the control group required blood transfusion. No thrombotic or thrombo-embolic events were reported. We conclude that Tranexamic acid use, as in our protocol, reduces postoperative bleeding in primary knee arthroplasty, with the absence of thrombo-embolic events.

Perioperative blood transfusions in hip and knee arthroplasty: a retrospective assessment of combined risk factors

INTRODUCTION

Accurate identification of patients at risk of blood transfusion can reduce complications and improve institutional resource allocation. Probabilistic models are used to detect risk factors and formulate patient blood management strategies. Whether these predictors vary among institutions is unclear. We aimed to identify risk factors among our patients who underwent total hip (THA) or knee (TKA) arthroplasty, and combine these predictors to improve our model.

MATERIALS AND METHODS

We retrospectively assessed risk factors among 531 adults who underwent elective THA or TKA from January 2016 to November 2018. Using relevant surgical and patient characteristics gathered from electronic medical records, we conducted univariable and multivariable analyses. For our logistic regression model, we measured the impact of independent variables (age, gender, operation type (THA or TKA) and preoperative hemoglobin concentration) on the need for a transfusion.

RESULTS

Of the 531 patients, 321 had THA (uncemented) and 210 had TKA. For the selected period, our transfusion rate of 8.1% (10.6% THA and 4.3% TKA) was low. Univariable analyses showed that lower BMI (p < 0.001) was associated with receiving a transfusion. Important factors identified through logistic regression analyses were age (estimated effect of an interquartile range increase in age: OR 3.89 [CI 95% 1.96-7.69]), TKA (OR - 0.77 [CI 95% - 1.57-0.02]), and preoperative hemoglobin levels (estimated effect of interquartile range increase in hemoglobin: OR 0.47 [CI 95% 0.31-0.71]). Contrary to findings from previous reports, gender was not associated with transfusion.

CONCLUSIONS

Previously published predictors such as advanced age, low preoperative hemoglobin, and procedure type (THA) were also identified in our analysis. However, gender was not a predictor, and BMI showed the potential to influence risk. We conclude that, when feasible, the determination of site-specific transfusion rates and combined risk factors can assist practitioners to customize care according to the needs of their patient population.

LEVEL OF EVIDENCE

Level 3, retrospective cohort study.

Are Risk Factors for Postoperative Significant Hemorrhage following Total Knee Arthroplasty Potentially Modifiable? A Retrospective Cohort Study

Total knee arthroplasty (TKA) is the treatment of choice for end-stage osteoarthritis (OA) of the knee, because it alleviates pain and restores function of the knee. However, TKA-associated hemorrhage and subsequent anemia remain a concern. Most previous studies have defined meaningful postoperative bleeding as blood loss > 500 mL or hemoglobin (Hb) drop > 20 g/L. Therefore, we defined significant hemorrhage as a postoperative Hb drop more than 20 g/L in this study, and we investigated possible risk factors related to significant hemorrhage in TKA and whether these risk factors are modifiable. This retrospective study was conducted through a comprehensive review of the perioperative records of patients with OA of the knee who underwent TKA between January 2009 and December 2015 at our hospital. Patients were allocated into two groups: patients in Group A had their Hb drop ≤ 20 g/L; patients in Group B had their Hb drop > 20 g/L. Factors analyzed included sex, age, body mass index (BMI), the American Society of Anesthesiologists (ASA) classification, comorbidities, preoperative platelet count, use of tranexamic acid (TXA), operation time, and type of anesthesia. A total of 3350 patients met the criteria for analysis, with 1782 patients allocated to Group A and 1568 patients to Group B. Five independent risk factors for significant hemorrhage were identified: male sex (odds ratio(OR), 1.29; 95% confidence interval(CI), 1.08−1.53; p = 0.005), age (OR, 1.02; 95% CI, 1.01−1.03; p = 0.001), use of TXA (OR, 0.39; 95% CI, 0.34−0.45; p < 0.001), spinal anesthesia versus general anesthesia (OR, 0.71; 95% CI, 0.56−0.90; p = 0.004), and preoperative platelet count (OR, 0.96; 95% CI, 0.93−0.98; p = 0.001). Of these identified risk factors, preoperative platelet count, use of TXA, and spinal anesthesia are modifiable. These potentially modifiable risk factors need to be taken into consideration when making both the perioperative care and anesthesia plan by surgeons and anesthesiologists, especially in patients at risk of significant hemorrhage.

An insight into the utilization of allogenic blood transfusion and factors affecting blood transfusion in total knee replacement surgery in a tertiary care hospital in Eastern India

BACKGROUND:

Significant blood loss and requirement of allogenic blood transfusion during or after total knee replacement (TKR) have been reported. Incidence of blood transfusion in TKR is highly variable and depends on several factors. We investigated the blood utilization in patients undergoing TKR in our hospital and depicted the important risk factors that determine the need of allogenic blood transfusion in primary unilateral TKR.

MATERIALS AND METHODS:

The study included 1241 consecutive patients undergoing primary unilateral total knee arthroplasty. All the surgeries were performed by a single surgical team of orthopedists following standard procedure. Patient and disease details were obtained from patient file and hospital information system. Compatibility test was performed in blood bank before blood reservation following mandatory guidelines. Details of test, blood issue, and blood transfusion were documented in the blood bank.

RESULTS:

Of 1241 enrolled patients, 1069 (86.2%) were female. The median age of patients was 66 years with mean preoperative hemoglobin of 9.9 g/dL. Allogenic blood transfused was needed in 223 (17.9%) patients. Diabetes mellitus, hypertension, thyroid disorders, and chronic heart diseases were the major comorbid conditions. Risk factors such as gender, American Society of Anesthesiologists score, preoperative hemoglobin, and intraoperative and postoperative blood losses were significantly associated with blood transfusion.

CONCLUSION:

The risk factors determining blood transfusion in TKR vary between studies, however, all centers should establish standard operating procedures describing the surgical procedure and transfusion support in TKR. In addition, each center may develop specific blood management strategy to rationalize blood transfusion in TKR and overall successful care in TKR.

Association between Type of Anesthesia and Risk of Blood Transfusion Events in Primary Unilateral Total Knee Arthroplasty: A Secondary Analysis Based on a Cohort Study in Singapore

This study evaluated whether the type of anesthesia independently related to risk of blood transfusion events in patients undergoing total knee arthroplasty (TKA) after adjusting for other covariates. This was a secondary analysis of a retrospective cohort study of patients undergoing primary unilateral TKA in Singapore. The independent variable was the type of anesthesia and the dependent variable was blood transfusion events. A multivariable logistic regression analysis was performed adjusting for variables that might affect the choice of anesthesia or blood transfusion events. Additional analyses examined this association by the subgroup analysis by using stratified multivariate logistic regression models. Of all 2,366 patients undergoing primary unilateral TKA, 120 (5.1%) developed blood transfusion events. Sixty-four (4.1%) of 1,560 patients with regional anesthesia (RA) developed blood transfusion events, compared with 56 (6.9%) of 806 patients with general anesthesia (GA; (p = 0.003). After adjusting for age, sex, preoperative hemoglobin, and other variables, patients who received RA had a decreased risk of blood transfusion events compared with those receiving GA (odds ratio [OR]: 0.53, 95% confidence interval [CI]: 0.35-0.81). This risk further decreased in male (OR: 0.20, 95% CI: 0.07-0.59) and participants whose operation time ≥ 90 minutes (OR: 0.39, 95% CI: 0.19-0.78). Our results indicated that patients receiving primary unilateral TKA who were managed with RA had a significantly decreased risk of blood transfusion events compared with those with GA, especially in male and participants whose operation time ≥ 90 minutes.

Development of a risk-oriented algorithm for the combined use of hemostatics and anticoagulants to prevent thrombosis and bleeding cases after total arthroplasty of knee or hip joints

Introduction: The goal of our study was to develop a risk-oriented algorithm for the combined use of hemostatics and anticoagulants in patients after total arthroplasty of the knee or hip joints to reduce the risk of thrombohemorrhagic complications.

Materials and methods: We performed a retrospective study (n=253). In group (Gr.) 1, the time interval (TI) between the administration of hemostatic and anticoagulant prophylaxis was ≤17 hours (n=145; 57.31%), and in Gr. 2 – 18-24 hours (n=108; 42.68%). We analyzed the influence of different factors on the development of thrombosis and bleeding cases after the operation.

Results and discussion: Thrombohemorrhagic complications were observed in 27 (10.67%) patients. Thrombosis in Gr. 1 was associated with the use of tranexamic acid, and were recorded 2.2 times more often than in Gr. 2 (p&lt;0.05). The development of thrombosis in Gr. 1 was influenced by: class II obesity, type 2 diabetes mellitus, myocardial infarction, venous pathology, age of patients &gt;75 years, for women – an initially low level of international normalized ratio, and activated partial thromboplastin time (APTT) (p&lt;0.05). The development of bleeding in Gr. 1 was influenced by: age &gt;75 years, among men and women – an increased preoperative level of APTT, for women – a decreased level of fibrinogen and platelets (p&lt;0.05).

Conclusion: To prevent thrombosis and bleeding after arthroplasty of large joints, the TI between the use of hemostatics and anticoagulants should be at least 18 hours, especially in patients with the above risk factors, in particular, when using tranexamic acid and low molecular weight heparins.

Perioperative Blood Transfusions Are Associated with a Higher Incidence of Thromboembolic Events After TKA: An Analysis of 333,463 TKAs

BACKGROUND

Given the morbidity, mortality, and financial burden associated with venous thromboembolism (VTE) after TKA, orthopaedic providers continually seek to identify risk factors associated with this devastating complication. The association between perioperative transfusion status and VTE risk has not been thoroughly explored, with previous studies evaluating this relationship being limited in both generalizability and power.

QUESTIONS/PURPOSES

Therefore, we sought to determine whether perioperative transfusions were associated with an increased risk of (1) pulmonary embolism (PE) or (2) deep vein thrombosis (DVT) after primary TKA in a large, multi-institutional sample.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) database was implemented for our analysis. The definitions of complications, such as DVT and PE, and risk adjustment validation is monitored by the central ACS NSQIP office to ensure participating hospitals are adhering to the same guidelines to log patients. Additionally, both preoperative and intraoperative/72 hour postoperative transfusion status is included for all patients. Therefore, ACS NSQIP was determined to be the most appropriate database for our analysis. All patients who underwent primary TKA between 2011 and 2018 were identified using Current Procedural Terminology code 27447. Primary TKAs designated as "non-elective" were excluded, thereby providing a cohort composed solely of patients undergoing unilateral primary elective TKA for further analysis. The final analysis included 333,463 patients undergoing TKA (mean age 67 ± 9 years, 62% female). Preoperative transfusions were received by < 0.01% (48 of 333,463) of the patients, while 4% (14,590 of 333,463) received a transfusion within the interim between the start of surgery up to 72 hours postoperatively. All missing values were imputed through multiple imputation by chained equation to avoid variable availability-based selection and the subsequent listwise deletion-associated bias in the estimate of parameters. A multivariable logistic regression analysis was conducted using variables identified in a univariate model to calculate adjusted odds ratios and 95% confidence intervals for risk factors associated with symptomatic DVT and/or PE. For variables that maintained significance in the multivariable model, an additional model without confounders was used to generate fully adjusted ORs and 95% CIs. A propensity score matched comparison between recipients versus nonrecipients (1:1) of transfusion (preoperative and intraoperative/72 hours postoperative) was then conducted to evaluate the independent association between DVT/PE development and patients' transfusion status. Significance was determined at a p value < 0.05.

RESULTS

Adjusted multivariable regression analysis accounting for patient age, sex, race, BMI, American Society of Anesthesiologists (ASA) class and baseline comorbidities demonstrated the absence of an association between preoperative (OR 1.75 [95% CI 0.24 to 12.7]; p = 0.58) or intraoperative/72 hours postoperative (OR 1.12 [95% CI 0.93 to 1.35]; p = 0.23) transfusions and higher odds of developing PE. Similar findings were demonstrated after propensity score matching. Although multivariable regression demonstrated the absence of an association between preoperative transfusion and the odds of developing DVT within the 30-day postoperative period (OR 1.85 [95% CI 0.43 to 8.05]; p = 0.41), intraoperative/postoperative transfusion was associated with higher odds of DVT development (OR 3.68 [95% CI 1.14 to 1.53]; p < 0.001) relative to transfusion naïve patients. However, this significance was lost after propensity score matching.

CONCLUSION

After controlling for various potential confounding variables such as ASA Class, age, anesthesia type, and BMI, the receipt of an intra- or postoperative transfusion was found to be associated with an increased risk of DVT. Our findings should encourage orthopaedic providers to strictly adhere to blood management protocols, further tighten transfusion eligibility, and adjust surgical approach and implant type to reduce the incidence of transfusion among patients with other DVT risk factors. Additionally, our findings should encourage a multidisciplinary approach to VTE prophylaxis and prevention, as well as to blood transfusion guideline adherence, among all providers of the care team.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Is Routine Hemoglobin Monitoring Necessary after Elective Hip and Knee Arthroplasty?

Background

Many orthopaedic units measure hemoglobin (Hb) levels after primary joint arthroplasty to identify patients with postoperative anemia. With the refinement of surgical techniques, blood loss in primary arthroplasty has decreased. The aim of this study was to investigate the postoperative Hb monitoring and transfusion practices in our own institution after elective hip or knee arthroplasty.

Methods

We conducted a retrospective audit of all patients who underwent elective total hip or knee arthroplasty in Galway University Hospital between March 1 and June 1, 2019. We recorded when they underwent postoperative Hb testing, whether or not they had a drop of Hb, which would indicate transfusion (<8 g/dL), and whether or not they were transfused. In patients who underwent transfusion, a chart review was performed to establish the presence of factors that would have triggered repeat Hb testing.

Results

One hundred thirty-six patients underwent elective primary hip or knee arthroplasty in the period. All had a full blood count sent on the first postoperative day. None (0%) had a clinically significant (to < 8g/dL) postoperative Hb drop on day 1. Eighteen (13.2%) patients underwent repeat testing on day 2 or subsequently. Eight (5.9%) exhibited a drop in Hb to less than 8 g/dL, with a mean Hb drop of 4.26 (standard error of the mean ± 0.862, standard deviation ± 0.98), and 5 (3.7%) proceeded to undergo allogenic blood product transfusion. All 5 underwent documented indications for repeat Hb testing.

Conclusions

There is no evidence for performing routine Hb testing on day 1 after elective hip or knee arthroplasty. We recommend that postoperative Hb testing should only be carried out on patients with additional indications.

Clinical Pharmacist Service Associated With Improved Outcomes and Cost Savings in Total Joint Arthroplasty

BACKGROUND

Institutions providing total joint arthroplasty (TJA) procedures are subject to substantial outcomes reporting, including those influencing payment for services. Although clinical pharmacists are well-poised to add value, a comprehensive approach to optimizing pharmacotherapy across the care continuum for TJA patients has not been described.

METHODS

This prospective, interventional, sequential cohort study was approved by our Institutional Review Board. The objective was to assess the impact of an Orthopedic Clinical Pharmacist service on institutional TJA complication rates and costs. Outcomes were compared for a Baseline period of July 2015 to February 2016 and a Post-implementation period of September 2016 to February 2017, allowing for a 6-month run-in period. Additionally, we pursued a post-discharge, RN-administered patient survey and an exploratory economic assessment.

RESULTS

A total of 1715 TJA procedures were performed at the institution during the 20-month study timeframe. Postoperative readmission rate (1.3% vs 4.8%, P = .002) and complication rate (1.8% vs 3.4%, P = .760) were lower in the Post-implementation period. Postoperative VTE rate decreased to zero in the Post-implementation period (0.0% vs 0.6%, P = .13) and average hospital length of stay was unchanged (2.8 vs 2.9 days). Patient self-rated understanding of discharge medications was improved and satisfaction with pharmacist interaction was very high. The service conferred an estimated $73,410 net annual cost savings to the institution.

CONCLUSION

Integration of a clinical pharmacist service for TJA patients was associated with clinically meaningful improvements in institutional outcomes, likely conferring substantial cost-benefit.

Effectiveness and safety of the use of antifibrinolytic agents in total-knee arthroplasty: A meta-analysis

BACKGROUND

Antifibrinolytic agents have been successfully used to reduce blood transfusion demand in patients undergoing elective knee arthroplasty. The purpose of this study was to investigate different antifibrinolytic agents for patients undergoing total-knee arthroplasty (TKA).

METHODS

We searched the randomized controlled trials assessing the effect of antifibrinolytic agents on TKA in MEDLINE, PubMed, Embase, and the Cochrane Library. Participants are divided into antifibrinolytic agent group and control group under TKA. Double extraction technology is used and the quality of its methodology is evaluated before analysis. Outcomes analyzed included blood loss, number of blood transfusions, rates of blood transfusion, and deep vein thrombosis (DVT).

RESULTS

A total of 28 randomized controlled trials involving 1899 patients were included in this study. Compared with the control group, the antifibrinolytic agents group exhibited significantly reduced the amounts of total blood loss (weighted mean difference [WMD] with 95% confidence interval [CI]: -272.19, -338.25 to -206.4), postoperative blood loss (WMD with 95% CI: -102.83, -157.64 to -46.02), average units of blood transfusion (risk ratio with 95% CI: 0.7, 0.12 to 0.24), and average blood transfusion volumes (WMD with 95% CI: -1.34, -1.47 to -1,21). Antifibrinolytic agents significantly reduced the rate of blood transfusions and did not increase the occurrence risk of intraoperative blood loss and DVT. Several limitations should also be acknowledged such as the heterogeneity among the studies.

CONCLUSION

The application of antifibrinolytic agents can significantly reduce blood loss and blood transfusion requirements. Additionally, these agents did not increase the risk of DVT in patients undergoing TKAs.

One-staged combined hip and knee arthroplasty: retrospective comparative study at mid-term follow-up

Background

To date, few knowledge is available about safety and effectiveness of one-staged combined hip and knee arthroplasty. The aim of our study was to evaluate, in a comparative fashion, complications and outcomes in patients who underwent one-staged hip and knee arthroplasty.

Methods

Forty-two patients were enrolled and allocated into two groups of 21 patients each: one-staged hip and knee arthroplasty (group A) and two-staged hip and knee arthroplasty (group B). The follow-up averaged 50.2 months. Postoperative complications and implant survivorship were assessed prospectively. Outcomes were evaluated with Harris Hip score (HSS), Western Ontario Mc-Ministry score for the hip (h-WOMAC), Knee Society score (KSS), and Western Ontario Mc-Ministry knee score (k-WOMAC). Hip and knee range of motion (ROM) were measured both preoperatively and at the last follow-up.

Results

Two (9.5%) patients in group A and three (14.3%) patients in group B developed complications (P = 0.8). Although a significant decrease in postoperative haemoglobin (Hgb) values was found in group A patients during the hospital stay, no differences in blood transfusions were found (P = 0.8). No significant differences were found comparing clinical-functional outcomes between the two groups, while a significant reduction of hospital length of stay was shown in group A patients.

Conclusions

One-staged combined hip and knee arthroplasty could be considered in patients with co-existing severe hip and knee osteoarthritis, providing similar complications and mid-term outcomes of two-staged procedures. However, the reproducibility safety and reliability of these procedures should be confirmed in prospective comparative randomised trials with more numerous patients.

Trial registration

Retrospectively registered

The incidence and risk factors for allogenic blood transfusion in total knee and hip arthroplasty

Background

Excessive blood loss in total joint arthroplasty (TJA) usually leads to an allogenic blood transfusion, which may cause adverse outcomes, prolonged length of hospitalization, and increased costs. The purpose of this study was to determine the incidence and risk factors for intraoperative and postoperative allogenic transfusion in patients undergoing primary unilateral total knee and hip arthroplasty (TKA and THA).

Methods

We conducted a retrospective study and enrolled consecutive patients undergoing primary unilateral TKA and THA at our institution between January 2010 and July 2014 (n = 1534). Information about allogenic transfusion was collected from medical records to determine the incidence. We performed univariate analysis and multivariate logistic regression analysis to identify the independent risk factors.

Results

Total, intraoperative, and postoperative transfusion rates were 17.9%, 7.9%, and 11.3%, respectively. The preoperative lower level of hemoglobin (Hb) (P < 0.001) and increased amount of intraoperative blood loss (P < 0.001) were independently associated with transfusion in TKA. The independent risk factors for transfusion in THA were female (P = 0.023), preoperative lower Hb level (P < 0.001), prolonged operation time (P < 0.001), and increased intraoperative blood loss (P < 0.001).

Conclusions

Given the high prevalence and potential risk of transfusion in TJA, interventions for identified risk factors should be used during the perioperative period.

Role of Suction Drain after Knee Arthroplasty in the Tranexamic Acid Era: A Randomized Controlled Study

Background

Postoperative suction drains are used after total knee arthroplasty to avoid intra-articular hematoma formation although they can increase blood loss due to a negative suction effect. The use of tranexamic acid to reduce blood loss may nullify this. The aim of this study was to compare outcomes in patients undergoing total knee arthroplasty with or without drains and to analyze whether the drain's diameter also has an impact.

Methods

This is a prospective randomized study of patients undergoing unilateral total knee arthroplasty performed by a single surgeon. The study population was divided into three groups (A, 10G drain; B, 12G drain; and C, no drain). Pain, blood loss, swelling, wound-related complications, functional outcomes and questionnaire-based outcomes were assessed postoperatively.

Results

Each group had 35 patients comparable in most demographic and pre- and intraoperative characteristics. During the first 6 hours postoperatively, opioid consumption was significantly higher when the drain was not used (p = 0.036). At 3 months postoperatively, new Knee Society Score (NKSS) was highest with the use of 12G drain (p = 0.018). However, NKSS at 1 year was comparable across the three groups. With the use of tranexamic acid, blood loss and incidence of soakage of dressing were unaffected by the presence or absence of a drain. The calf girth, suprapatellar girth, soakage of dressing and range of motion were comparable in all three groups. There was no incidence of surgical site infection or deep vein thrombosis.

Conclusions

Presence of a suction drain significantly reduces opioid consumption during the first 6 hours after total knee arthroplasty. Use of a drain made no difference to the functional outcome at 1 year postoperatively. With the use of tranexamic acid in total knee arthroplasty, the total blood loss and the requirement of blood transfusion were unaffected by the presence or absence of closed suction drainage or by the bore of the drain used. The clinical parameters such as swelling, range of motion, infection and deep vein thrombosis also remained the same.

Effectiveness and safety of tranexamic acid in total joint arthroplasty

Total joint arthroplasty is associated with significant blood loss, that could result in the need of blood transfusions. Several techniques are being utilised to limit the volume of blood loss, in order to avoid transfusion. In this review, we look at blood loss in total joint arthroplasty and the perioperative strategies to limit the loss of blood. With the use of tranexamic acid gaining popularity, we analyse the published literature on its use in patients undergoing total joint arthroplasty. We have found that published studies favour using tranexamic acid in total joint arthroplasty as a safe and effective method of reducing blood loss.

Efficacy and safety of topical tranexamic acid in knee arthroplasty

INTRODUCTION AND OBJECTIVE

Tranexamic acid (TXA) is commonly used to control postoperative blood loss in total knee arthroplasty. In order to avoid adverse effects associated with intravenous administration, topical use has been proposed as an alternative. Our aim was to evaluate the efficacy and safety of topical TXA in total knee arthroplasty.

MATERIAL AND METHODS

A total of 90 patients scheduled for unilateral total knee arthroplasty were included in a prospective randomised study. All surgeries were performed under spinal anaesthesia, tourniquet and the same postoperative protocol. Patients were allocated to one of the 3 groups according to the application of TXA: group A (n=30) 1g of topical TXA; group B (n=30) 1g of TXA intravenous and in group C or the control group (n=30) no drug was administrated. Parameters related to blood loss and drain outputs were compared between the 3 groups.

RESULTS

The results revealed that post-operative decrease in haemoglobin level was significantly lower in group A (1.95g/dL) than group B (2.25g/dL) and group C (2.96g/dL), P<.01. Total postoperative blood loss was lower in group A (195mL) than group B (466mL) and group C (718mL), P<.01. There was no significant difference in complications and allogenic blood transfusion rate between the 3 groups.

CONCLUSIONS

According to the results, topical application of 1g TXA significantly reduced blood loss in patients undergoing total knee arthroplasty more than intravenous or no administration of TXA.