The predictive power of baseline hemoglobin for transfusion risk in surgery patients

Assessing the predictive value of pre- and post-operative inflammatory markers in patients undergoing total knee arthroplasty

BACKGROUND AND OBJECTIVE

Total Knee Arthroplasty (TKA) has proven highly effective in improving quality of life for patients with severe knee conditions. Despite advancements, surgical complications such as periprosthetic joint infections (PJIs) pose risks. The potential predictive value of pre- and post-operative inflammatory markers like neutrophil-to-lymphocyte ratio (NLR), D-dimer, and albumin levels on surgical outcomes is garnering attention. There is a growing interest in leveraging these markers to enhance patient selection and outcome prediction in the context of TKA.Focusing on the natural course of these markers, and the incidence of PJIs and to refine perioperative care strategies, improve patient outcomes, and identify high-risk patients for targeted intervention.

METHODS

The study included 94 patients who underwent total knee arthroplasty (TKA) between 2019 and 2023. Blood tests were conducted before surgery and at 1, 3, 7, and 15 days after surgery to assess various parameters including white blood cell count, neutrophils, lymphocytes, platelets, hemoglobin, C-reactive protein, D-dimers, total protein, albumin, and total cholesterol values and ratios.

RESULTS

Following total knee arthroplasty (TKA), key observations in blood markers included a sharp rise in white blood cell (WBC) counts from 5.81 to 10.22 (*10^9/L) on the first day post-surgery, with levels returning close to preoperative values by day-15. Neutrophil counts similarly increased from 3.46 to 8.50 (*10^9/L) on day-1, decreasing to 4.01 by day-15. Hemoglobin levels significantly decreased from 115.70 g/L to 90.62 by day-3 before improving to 100.30 by day-15. C-reactive protein (CRP) levels also saw a significant rise from 6.15 mg/L to a peak of 47.07 on day-3, then reducing to 10.55 by day-15, indicating a response to inflammation.

CONCLUSION

Following total knee arthroplasty (TKA), a significant initial postoperative increase in white blood cell count, neutrophils, and C-reactive protein levels, indicative of an acute inflammatory response, before returning towards baseline values by day 15. Hemoglobin levels displayed a notable dip post-surgery, gradually improving by the study's end. These patterns emphasize the dynamic nature of inflammatory and hematological responses after TKA, highlighting their potential role in predicting surgical outcomes and guiding postoperative care.

How to avoid systematic postoperative blood test after total hip arthroplasty: A new risk scoring system compared to Wu's score

BACKGROUND

Routine laboratory studies are often performed following total hip arthroplasty (THA). However, lately, their necessity has been challenged and risk factors for postoperative transfusion are still debated. Recently, a risk scoring system to single out patients that should have a postoperative blood test has been published by Wu et al. The purposes of this retrospective study were: (1) to validate this recently published risk scoring system to identify patients who should have a postoperative laboratory test; (2) to single out risk factors of postoperative transfusion; (3) to determine if another score can more accurately predict the need for postoperative transfusion.

HYPOTHESIS

Wu et al.'s risk scoring system can accurately identify patients who should have a postoperative blood test.

METHODS

In all, 1693 patients who underwent primary THAs between June 2015 and October 2020 were screened for potential eligibility to include 1000 patient for analysis. Preoperative and postoperative blood tests were done for every patient. Clinical information and laboratory results were retrospectively collected and analyzed. A descriptive analysis followed by univariate and multivariate analysis were sequentially performed. A multiple logistic regression model was employed to determine a formula predicting the transfusion risk called THABUS for Total Hip Arthroplasty Blood test Usefulness Score. The risk scoring system for complete blood count published by Wu et al. in may 2020 was performed for every patient and compared to the THABUS predictive model.

RESULTS

The transfusion rate was 2.3% (23/1000). The risk-scoring system published by Wu and al. showed that a laboratory test was necessary for 60.6% (606/1000) however 13% (3/23) of the patients who needed a blood transfusion were missed by the risk-scoring system, giving it a sensitivity of 86.95% and a specificity of 40%. Increasing age, arterial hypertension, female gender, low preoperative hemoglobin, ASA score≥2 and diagnosis of osteonecrosis of the femoral head were significantly associated with postoperative transfusion. The THABUS formula can predict the risk for transfusion with a sensibility of 96.65% and a specificity of 75.54%. In our cohort of 1000 patients, following the THABUS formula would have led to 261 postoperative blood test and cost savings of 32,132$. Only one patient (4.3%) was missed by our new score. The THABUS formula is significantly better than Wu et al.'s complete blood count score in identifying both patient that will need a transfusion (p<0.01) and those who shouldn't have a postoperative blood test (p<0.001). Medical intervention because of creatinine or electrolytes abnormality was needed in 0.3% (3/1000) of patients.

DISCUSSION

In this study Wu et al.'s recently published complete blood count risk-scoring system was not validated. However, in the studied population the THABUS formula can accurately target patients who might need a transfusion. The use of the THABUS formula could reduce hospitalization costs without compromising the patients' safety.

LEVEL OF EVIDENCE

III, case-control study.

The comparative and added prognostic value of biomarkers to the Revised Cardiac Risk Index for preoperative prediction of major adverse cardiac events and all-cause mortality in patients who undergo noncardiac surgery

BACKGROUND

The Revised Cardiac Risk Index (RCRI) is a widely acknowledged prognostic model to estimate preoperatively the probability of developing in-hospital major adverse cardiac events (MACE) in patients undergoing noncardiac surgery. However, the RCRI does not always make accurate predictions, so various studies have investigated whether biomarkers added to or compared with the RCRI could improve this.

OBJECTIVES

Primary: To investigate the added predictive value of biomarkers to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Secondary: To investigate the prognostic value of biomarkers compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery. Tertiary: To investigate the prognostic value of other prediction models compared to the RCRI to preoperatively predict in-hospital MACE and other adverse outcomes in patients undergoing noncardiac surgery.

SEARCH METHODS

We searched MEDLINE and Embase from 1 January 1999 (the year that the RCRI was published) until 25 June 2020. We also searched ISI Web of Science and SCOPUS for articles referring to the original RCRI development study in that period.

SELECTION CRITERIA

We included studies among adults who underwent noncardiac surgery, reporting on (external) validation of the RCRI and: - the addition of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of biomarker(s) to the RCRI; or - the comparison of the predictive accuracy of the RCRI to other models. Besides MACE, all other adverse outcomes were considered for inclusion.

DATA COLLECTION AND ANALYSIS

We developed a data extraction form based on the CHARMS checklist. Independent pairs of authors screened references, extracted data and assessed risk of bias and concerns regarding applicability according to PROBAST. For biomarkers and prediction models that were added or compared to the RCRI in ≥ 3 different articles, we described study characteristics and findings in further detail. We did not apply GRADE as no guidance is available for prognostic model reviews.

MAIN RESULTS

We screened 3960 records and included 107 articles.   Over all objectives we rated risk of bias as high in ≥ 1 domain in 90% of included studies, particularly in the analysis domain. Statistical pooling or meta-analysis of reported results was impossible due to heterogeneity in various aspects: outcomes used, scale by which the biomarker was added/compared to the RCRI, prediction horizons and studied populations.  Added predictive value of biomarkers to the RCRI Fifty-one studies reported on the added value of biomarkers to the RCRI. Sixty-nine different predictors were identified derived from blood (29%), imaging (33%) or other sources (38%). Addition of NT-proBNP, troponin or their combination improved the RCRI for predicting MACE (median delta c-statistics: 0.08, 0.14 and 0.12 for NT-proBNP, troponin and their combination, respectively). The median total net reclassification index (NRI) was 0.16 and 0.74 after addition of troponin and NT-proBNP to the RCRI, respectively. Calibration was not reported. To predict myocardial infarction, the median delta c-statistic when NT-proBNP was added to the RCRI was 0.09, and 0.06 for prediction of all-cause mortality and MACE combined. For BNP and copeptin, data were not sufficient to provide results on their added predictive performance, for any of the outcomes. Comparison of the predictive value of biomarkers to the RCRI  Fifty-one studies assessed the predictive performance of biomarkers alone compared to the RCRI. We identified 60 unique predictors derived from blood (38%), imaging (30%) or other sources, such as the American Society of Anesthesiologists (ASA) classification (32%). Predictions were similar between the ASA classification and the RCRI for all studied outcomes. In studies different from those identified in objective 1, the median delta c-statistic was 0.15 and 0.12 in favour of  BNP and NT-proBNP alone, respectively, when compared to the RCRI, for the prediction of MACE. For C-reactive protein, the predictive performance was similar to the RCRI. For other biomarkers and outcomes, data were insufficient to provide summary results. One study reported on calibration and none on reclassification. Comparison of the predictive value of other prognostic models to the RCRI   Fifty-two articles compared the predictive ability of the RCRI to other prognostic models. Of these, 42% developed a new prediction model, 22% updated the RCRI, or another prediction model, and 37% validated an existing prediction model. None of the other prediction models showed better performance in predicting MACE than the RCRI. To predict myocardial infarction and cardiac arrest, ACS-NSQIP-MICA had a higher median delta c-statistic of 0.11 compared to the RCRI. To predict all-cause mortality, the median delta c-statistic was 0.15 higher in favour of ACS-NSQIP-SRS compared to the RCRI. Predictive performance was not better for CHADS₂, CHA₂DS₂-VASc, R₂CHADS₂, Goldman index, Detsky index or VSG-CRI compared to the RCRI for any of the outcomes. Calibration and reclassification were reported in only one and three studies, respectively.

AUTHORS' CONCLUSIONS

Studies included in this review suggest that the predictive performance of the RCRI in predicting MACE is improved when NT-proBNP, troponin or their combination are added. Other studies indicate that BNP and NT-proBNP, when used in isolation, may even have a higher discriminative performance than the RCRI. There was insufficient evidence of a difference between the predictive accuracy of the RCRI and other prediction models in predicting MACE. However, ACS-NSQIP-MICA and ACS-NSQIP-SRS outperformed the RCRI in predicting myocardial infarction and cardiac arrest combined, and all-cause mortality, respectively. Nevertheless, the results cannot be interpreted as conclusive due to high risks of bias in a majority of papers, and pooling was impossible due to heterogeneity in outcomes, prediction horizons, biomarkers and studied populations. Future research on the added prognostic value of biomarkers to existing prediction models should focus on biomarkers with good predictive accuracy in other settings (e.g. diagnosis of myocardial infarction) and identification of biomarkers from omics data. They should be compared to novel biomarkers with so far insufficient evidence compared to established ones, including NT-proBNP or troponins. Adherence to recent guidance for prediction model studies (e.g. TRIPOD; PROBAST) and use of standardised outcome definitions in primary studies is highly recommended to facilitate systematic review and meta-analyses in the future.

A rationale for universal tranexamic acid in major joint arthroplasty: overall efficacy and impact of risk factors for transfusion

BACKGROUND

Tranexamic acid (TXA) therapy is effective in reducing postoperative red blood cell (RBC) transfusion in total joint arthroplasty (TJA), yet uncertainty persists regarding comparative efficacy and safety among specific patient subgroups. We assessed the impact of a universal TXA protocol on RBC transfusion, postoperative hemoglobin (Hb), and adverse outcomes to determine whether TXA is safe and effective in TJA, both overall and in clinically relevant subgroups.

STUDY DESIGN AND METHODS

A retrospective observational study was performed on patients undergoing TJA at our institution spanning 1 year before and after the implementation of a universal protocol to administer intravenous (IV) TXA. The primary outcome was percentage of patients transfused, and secondary outcomes were perioperative Hb and occurrence of adverse events (death, myocardial infarction, stroke, seizure, pulmonary embolism, deep vein thrombosis, and acute kidney injury ). Outcomes were compared in pre- and post-protocol groups with χ² analysis. Logistic regression compared risk of transfusion in pre- and post-protocol subgroups of patients with differing risk for transfusion (anemia, body mass index [BMI], and sex).

RESULTS

No differences were found in baseline patient characteristics across pre- and post-protocol groups (n = 1084 and 912, respectively). TXA use increased from 32.3% to 92.2% while transfusion rates decreased from 10.3% to 4.8% (p < 0.001). Postoperative Day 3 Hb increased from 95.8 to 101.4 g/L (p < 0.001). Logistic regression demonstrated reduced transfusion in post-protocol subgroups regardless of sex, anemia, or BMI (p < 0.001). No increase in adverse events was observed (p = 0.8451).

CONCLUSIONS

Universal TXA was associated with a reduction of RBC transfusion, overall and in clinically relevant subgroups, strengthening the rationale for universal therapy.

Acute Blood Loss Anemia in the Octogenarian Total Knee Arthroplasty, Estimated Blood Loss and Transfusions Rates

INTRODUCTION

Acute blood loss anemia is an expected morbidity after a total knee replacement. The purpose of this study is to quantify the rates of blood transfusions in the octogenarian population after a total knee replacement and its association with the surgeon's estimated blood loss (EBL).

METHODS

This is a retrospective review of the senior orthopedic surgeon's charts. All patients were 80 years of age, or older at the time of surgical intervention. All patients with the diagnosis of primary osteoarthritis where included.

RESULTS

A total 74 total knee arthroplasties were considered, in a total of 64 patients. Overall, 53% patients had an uneventful stay without a blood transfusion. The rates of transfusions increased with EBLs of 200, 250, and >250 ml with rates of 43%, 80%, and 55 % respectively. The average hematocrit of all patients that were transfused was 33.98, compared to 38.20 for the patients that were not transfused.

CONCLUSION

47% of patients required a blood transfusion during their hospital course regardless of the EBL estimated by the surgeon during surgery. The average hematocrit was found to be lower in the group that was transfused.

PUBLICATION INDICES

Pubmed.

Ninety-Day Morbidity and Mortality in Risk-Screened and Optimized Patients Undergoing Two-Team Fast-Track Simultaneous Bilateral TKA Compared With Unilateral TKA-A Prospective Study

BACKGROUND

Simultaneous bilateral total knee arthroplasty (SBTKA) offers significant socioeconomic benefits. However, retrospective studies and public health data show increased mortality and morbidity rates in patients undergoing SBTKA compared with those undergoing unilateral TKA (UTKA), and there have been recommendations against the use of SBTKA. High-volume centers, which feature careful patient selection and fast-tracked surgery, continue to perform SBTKA and have published their results in favor of the procedure. However, the quality of evidence remains poor.

METHODS

We prospectively examined 90-day morbidity and mortality of SBTKA compared with UTKA in risk-screened and optimized patients in our high-volume joint replacement facility. A total of 1200 consecutive patients were recruited in each arm.

RESULTS

Ninety-day mortality was higher in SBTKA patients than in UTKA patients (0.58% vs 0.42%, respectively; P = .5646). Overall procedure-related complications were significantly higher in the SBTKA group (7.25% vs 4.42%, respectively; P = .0034). The relative risk of cardiovascular complications in SBTKA patients was 6.5 times higher than that in UTKA patients (1.08% vs 0.17%, respectively; P = .0136). Neurological complications were 9.5 times more common in the SBTKA group (1.58% vs 0.17%, respectively; P = .0024). All other complications were comparable in the 2 groups.

CONCLUSION

Risk screening and preoperative optimization reduce mortality and overall complication rates in SBTKA patients; however, overall procedure-related complications, specifically cardiovascular and neurological, remain significantly high in SBTKA patients, for which a guarded approach is recommended.

A novel combination of four flavonoids derived from Astragali Radix relieves the symptoms of cyclophosphamide-induced anemic rats

By using a feedback system control scheme, the best combination of formononetin, ononin, calycosin, and calycosin‐7‐O‐β‐d‐glucoside derived from Astragali Radix was shown to activate a hypoxia response element, a regulator for erythropoietin (EPO) transcription, in kidney fibroblast. In cyclophosphamide‐induced anemic rats, the treatment of combined flavonoids, or EPO, improved the levels of red blood cells, white blood cells, hemoglobin, and hematocrit. In addition, the altered levels of antioxidant capacity, super oxidase dismutase, and malondialdehyde, triggered in anemic rats, were restored to control levels by the treatment of flavonoids. Here, we proposed a possible therapy by using the common flavonoids in treating anemia.

Complete blood count before and after total hip or knee arthroplasty

PURPOSE

To validate our transfusion protocol based on pre- and post-operative complete blood count (CBC) data in patients undergoing primary total hip or knee arthroplasty (THA or TKA).

METHODS

Records of 113 men and 205 women aged 32 to 94 (mean, 70) years who underwent primary uncemented THA (n=123) or cemented TKA (n=195) for osteoarthritis by 2 senior surgeons were reviewed. A post-surgical drain was used in 29 THA patients and 74 TKA patients, based on the surgeon's preference. CBC was assessed preoperatively, during postanaesthesia care, and at the beginning of postoperative days 1, 2, and 3 to determine their predictive power for transfusion rate. According to our transfusion protocol, blood was transfused when the haemoglobin (Hb) level was <80 g/l, or when hypotension, tachycardia, light-headedness, dizziness, or syncope occurred.

RESULTS

Respectively in 123 and 195 patients who underwent THA and TKA, the transfusion rates within 3 days were 31.7% (n=39) and 25.6% (n=50). No patient required transfusion during postanaesthesia care; the transfusion rates of all patients during day 1 to day 2 and day 2 to day 3 were 15.1% (n=48) and 12.9% (n=41), respectively. The transfusion rate was higher in women than men (36.6% vs. 12.4%, p<0.001), but did not differ significantly in patients with or without a post-surgical drain (29.1% vs. 27.4%, p=0.754). Respectively for the Hb level of <130 g/l, 130-150 g/l, and >150 g/l, the overall transfusion rates were 48.5%, 22.0%, and 4.3% based on the preoperative level; 32.6%, 7.6%, and 0% based on the postanaesthesia care level; and 28.9%, 8.3%, and 0% based on the day 1 level. The predictive power of the preoperative Hb level was highest, followed by that during postanaesthesia care and the on day 1.

CONCLUSION

CBC during postanaesthesia care is no more predictive than preoperative CBC. Preoperative optimisation and close monitoring of the Hb level from day 1 to day 3 is recommended.

Prevention of Periprosthetic Joint Infection

Periprosthetic joint infection (PJI) has moved into the first place as the cause of failure following total knee arthroplasty (TKA). Recent studies have shown that PJI results in higher mortality in patients than many cancers. The economic burden of treating PJI is likely to exceed $1 billion this year in the US. Thus, it is paramount that all efforts are invested to prevent this dreaded complication after total joint arthroplasty (TJA). This article summarizes some of the most effective and proven strategies for prevention of PJI. It is hoped that the article will be of benefit to the readers of the journal.

Clinical experience with tranexamic acid during primary total hip arthroplasty

We examined whether a single 1-gram preoperative dose of tranexamic acid (TXA) was effective in reducing 1) allogeneic blood transfusion, 2) haemoglobin (Hb) decreases, and 3) perioperative blood loss following primary total hip arthroplasty (THA) and resurfacing hip arthroplasty (RHA). One hundred and thirty-two patients (88 THA, 44 RHA; 66M, 66F; mean age = 58.2 years) who received TXA were compared with a control group matched for starting Hb, body mass index (BMI), age and gender. For the THR, transfusion rates were 4.5% and 19.3% for the TXA and control groups, respectively (p = 0.001) with no difference for the resurfacing patients. The mean overall Hb decrease was significantly lower in the TXA treatment groups for both THA and RHA patients (p<0.0001 and p = 0.01 respectively). 1 g of tranexamic acid administered preoperatively significantly reduced the mean decrease in haemoglobin as well as risk of transfusion.

National trends in spinal fusion for pediatric patients with idiopathic scoliosis: demographics, blood transfusions, and in-hospital outcomes

STUDY DESIGN

Analysis of population-based national hospital discharge data collected for the Nationwide Inpatient Sample database.

OBJECTIVE

To analyze trends in spinal fusion for pediatric patients with idiopathic scoliosis on a national level with regard to demographics, blood transfusions, and in-hospital outcomes.

SUMMARY OF BACKGROUND DATA

Spinal fusion for pediatric patients with idiopathic scoliosis is required for rapid curve progression. For such patients and their families, blood transfusions and complications are important aspects of the surgery.

METHODS

The Nationwide Inpatient Sample database was used to identify pediatric patients with idiopathic scoliosis who underwent spinal fusion from 2000 to 2009 using the International Classification of Diseases, Ninth Revision, Clinical Modification codes. Demographics of the patients were retrieved. Trends in demographics, blood transfusion methods, and in-hospital outcomes were analyzed.

RESULTS

The total number of patients included in this study was 43,983. A total of 30.4% of patients received a blood transfusion. Predonated autologous blood transfusions decreased over time, whereas perioperative autologous blood transfusions increased over time (P < 0.05, respectively). The in-hospital overall complication rate was 14.4%. The respiratory complication rate was the highest among complications; however, the rate decreased over time (P = 0.003). In-hospital blood transfusion, complication, and mortality rates were high in certain subgroups of patients, such as those with increased Elixhauser Comorbidity Score and those who underwent anterior and posterior fusion. The mean length of hospital stay decreased over time (P = 0.043).

CONCLUSION

During the last decade, 30% of pediatric patients with idiopathic scoliosis who underwent spinal fusion received some type of blood transfusion; and strategies for blood transfusion methods have changed over the years. A decreasing trend in the respiratory complication rate and reduction in length of hospital stay may indicate better postoperative care.

LEVEL OF EVIDENCE

3.

Trends in the utilization of blood transfusions in spinal fusion in the United States from 2000 to 2009

STUDY DESIGN

Retrospective study.

OBJECTIVE

The purpose of this study was to examine the trends in the utilization of blood transfusions in spinal fusion in the United States from 2000 to 2009.

SUMMARY OF BACKGROUND DATA

Spinal fusion is among the most common surgical procedures that necessitate blood transfusion. Blood transfusion methods include predonated autologous blood transfusion (PR-ABT), perioperative autologous blood transfusion (PE-ABT) (intraoperative and postoperative blood collection), and allogeneic blood transfusion (ALBT). The trends in the utilization of these blood transfusion methods in spinal fusion during the past decade are uncertain.

METHODS

The Nationwide Inpatient Sample was used to identify patients who underwent spinal fusion from 2000 to 2009, using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes. Patients who received PR-ABT, PE-ABT, and ALBT were identified using the appropriate ICD-9-CM codes. Patient demographics, surgical variables, and hospital characteristics data were retrieved. Trends in the utilization of blood transfusions were analyzed.

RESULTS

From 2000 to 2009, there was an increasing trend in the ALBT rate (4.3%-8.0%, P < 0.001) and a decreasing trend in the PR-ABT rate (2.6%-0.7%, P < 0.001) in patients who underwent spinal fusion. The overall blood transfusion and PE-ABT rates remained stable. The ALBT rate was high in the subgroups of patients, such as pediatric and elderly patients, female patients, patients with increased Elixhauser Comorbidity Score, Medicare patients, and patients who underwent thoracolumbar, posterior, and anterior and posterior fusion.

CONCLUSION

During the past decade, the ALBT rate increased, whereas the PR-ABT rate decreased in patients who underwent spinal fusion in US hospitals. The overall blood transfusion rate remained stable; however, it may be reduced by using a patient blood management program, targeting the subgroups of patients with the high ALBT rate.

LEVEL OF EVIDENCE

3.

Bilateral total knee arthroplasty in a one-stage surgical procedure

INTRODUCTION

Bilateral total knee arthroplasty (TKA) in a one-stage surgical procedure has the advantage of a single hospital stay, shorter rehabilitation, and reduced patient management costs. However, until now the use of this strategy has been limited by the fear of a higher rate of perioperative complications. The hypothesis of this study was that in selected patients, this management strategy would not result in any serious complications.

MATERIALS AND METHODS

This prospective 24-month pilot study was performed in a continuous series of patients without a control group. Inclusion criteria were bilateral non-infectious gonarthropathy, in patients classified as American Society of Anesthesiology (ASA) 1 or 2 and presenting with a preoperative hemoglobin level of at least 13g/dL. All patients underwent a pre- and postoperative evaluation using the International Knee Society (IKS) and Knee Injury and Osteoarthritis Score (KOOS) scores.

RESULTS

Thirty patients were included in the study (25 women, mean age 70.3years old [32 to 88years]; five ASA 1 and 25 ASA 2). All patients were followed-up and evaluated for a mean 18months (6 to 30months). Three deep vein thromboses, one cardiopulmonary accident and three confusional states were reported, but there were no perioperative deaths, pulmonary embolisms, nosocomial infections or revision procedures. At 18months follow-up the IKS score had improved from 98 (33-139) preoperatively to 169 (62-200) postoperatively. The five items of the KOOS score improved significantly.

DISCUSSION

This preliminary series confirms that bilateral total knee replacement in a one-stage surgical procedure is a reliable alternative to a two-stage procedure in ASA 1 and 2 patients. Because of the savings in health costs with this strategy, public healthcare authorities should provide support by creating and sponsoring a specific group for further study.

LEVEL OF EVIDENCE

4, prospective, no control group.

The effect of surgeon volume on the need for transfusion following primary unilateral hip and knee arthroplasty

INTRODUCTION

we reviewed transfusion practice following primary hip and knee arthroplasty with emphasis on the relationship between surgeon volume and the need for transfusion.

MATERIALS/METHODS

review of a consecutive series of 508 primary, elective, unilateral arthroplasties (248 THR/260 TKR) performed over a 12-month period. Data were analysed to determine the overall rate of transfusion and the details of any such transfusion. Secondarily, multivariate regression was performed to determine the effects of surgeon volume and other recorded variables upon the need for transfusion. For the purpose of analysis we classified surgeons doing more than 52 arthroplasties a year as "high volume" and surgeons performing less than this number as "low volume".

RESULTS

transfusion rates were 10% and 7% following THR and TKR. Multivariate analysis demonstrated that surgeon volume (<52 operations/yr vs. >52 operations/yr) and preoperative Hb<12g/dl were the only significant determinants of a need for postoperative transfusion (p<0.01). High volume and low volume surgeons transfused 5% vs. 17%, respectively (RR=3.3 (95%CI 1.5-9.1) p=0.003) following THR and 4% vs. 13% (RR=3.6 (95%CI 1.4-9.3) p=0.006) following TKR.

DISCUSSION AND CONCLUSION

High volume surgeons have significantly lower transfusion rates when compared to nationally accepted figures.

An individualized pre-operative blood saving protocol can increase pre-operative haemoglobin levels and reduce the need for transfusion in elective total hip or knee arthroplasty

We have prospectively evaluated the efficacy of an individualized pre-operative blood saving protocol in elective total hip arthroplasty (THA) or total knee arthroplasty (TKA). The primary aim was to obtain a pre-operative haemoglobin (Hb) level of > or =14 g dL(-1). A reduction in requirements for allogeneic transfusion was considered the second aim. Several strategies are available for increasing pre-operative Hb levels and reducing red blood cell (RBC) transfusions following THA or TKA, but the success of these programmes depends on selecting the most appropriate treatment for each patient. Three hundred and five patients with an indication of elective THA or TKA were individually assigned to the following strategies according to Hb and ferritin levels and medical conditions: (a) no pre-operative intervention, (b) oral iron therapy, (c) intravenous (i.v.) iron therapy, (d) recombinant human erythropoietin alpha with i.v. iron and (e) pre-operative autologous donation (PAD) plus oral iron. Eighty-two percent of the patients reached a pre-operative Hb level of > or =14 g dL(-1) compared with 62% of patients with Hb levels of > or =14 g dL(-1) at the baseline visit. Treatment with PAD showed a significant reduction in the pre-operative Hb levels. The rate of RBC transfusion was 18.8% compared with 31.5% of matched historic group (P < 0.001). In conclusion, all patients scheduled to undergo THA or TKA should be candidates for an individualized pre-operative blood salvage programme.

Blood use in elective surgery: the Austrian benchmark study

BACKGROUND

Benchmarking transfusion activity may help to eliminate inappropriate use of blood products. The goal of this study was to measure and to compare the current transfusion practice and to identify predictors of transfusion in public hospitals to develop strategies to optimize transfusion practices.

STUDY DESIGN AND METHODS

This was a prospective observational study in 18 randomly selected public hospitals from April 2004 to February 2005. Primary outcome measures were the amount of intra- and postoperative blood components transfused and intercenter variability of transfusion rate. Secondary outcome measures were prevalence of preoperative anemia, calculated perioperative blood loss, and lowest measured perioperative hemoglobin (Hb) level.

RESULTS

Adult patients undergoing primary unilateral total hip replacement (THR, n = 1401), primary unilateral knee replacement (TKR, n = 1296), hemicolectomy (HECOC, n = 148), and coronary artery bypass graft (CABG) surgery (n = 777) were enrolled. Due to the small number, data of HECOC patients were not fully analyzed. In the remaining procedures, there was a large intercenter variability in the percentage of patients who received transfusions: THR 16 to 85 percent, TKR 12 to 87 percent, and CABG 37 to 63 percent. In the patients who received transfusions, the number of red blood cells (RBC) units transfused varied significantly. There was also a considerable intercenter variability in RBC loss. The prevalence of preoperative anemia was 19 percent and identical in both sexes. The incidence of preoperative anemia was three times higher in patients who received transfusions compared to those who did not.

CONCLUSION

This study demonstrates a high intercenter variability in RBC transfusions and RBC loss in standard surgical procedures. Whereas the variability in blood loss remains largely unexplained, the main predictors for allogeneic RBC transfusions are preoperative and nadir Hb and surgical RBC loss.

Blood transfusion requirement prediction in patients undergoing primary total hip and knee arthroplasty

The aim of this study was to identify the clinical factors associated with the need for peri-operative blood transfusion in non-anaemic patients undergoing hip or knee arthroplasty. We prospectively evaluated 162 consecutive patients who underwent total hip or knee arthroplasty. Analysis was performed to establish the relationship between all independent variables and the need for postoperative transfusion. Univariate analysis revealed a significant relationship between the need for postoperative blood transfusion and the pre-operative haemoglobin levels (P= 0.001), weight (P= 0.019) and age (P= 0.018). Multivariate analysis identified a significant relationship only between the need for transfusion and the pre-operative haemoglobin level (P= 0.0001). The pre-operative haemoglobin level of the patient was the only variable to independently predict the need for blood transfusion after primary hip or knee arthroplasty.

Autologous blood donation and subsequent blood use in patients undergoing total knee arthroplasty

Autologous blood donation is designed to avoid complications from allogeneic blood, leaving units of blood in the general blood supply. It is unclear how efficient these programmes are in accomplishing these goals. It is unclear if autologous donation provokes increased need for any transfusion following surgery and whether it can be avoided in low-risk surgeries. Of 430 patients undergoing unilateral primary knee replacement arthroplasty over 12 months in our hospital, 309 had autologous donations and 121 did not. Of the 121 patients who did not donate, 36% completed surgery without transfusion, whereas only 17% of those who had autologous donations did so (P < 0.05). Age less than 65 years, higher baseline and postoperative haemoglobin levels were associated with lower transfusion rates. Patients who had autologous donations were approximately four times more likely to be transfused. As the number of autologous units donated increased, transfusions following surgery increased. Autologous donation did reduce allogeneic blood transfusions. Therefore, autologous blood donation for unilateral total knee arthroplasty is associated with overall increased transfusion rates, but with reduced need for allogeneic blood, independent of other clinical factors associated with transfusion. Therefore, there is need for reconsideration of these programmes relative to specific surgeries.

A prospective, randomised, controlled trial of the use of drains in total hip arthroplasty

The routine use of surgical drains in total hip arthroplasty remains controversial. They have not been shown to decrease the rate of wound infection significantly and can provide a retrograde route for it. Their use does not reduce the size or incidence of post-operative wound haematomas. This prospective, randomised study was designed to evaluate the role of drains in routine total hip arthroplasty. We investigated 552 patients (577 hips) undergoing unilateral or bilateral total hip arthroplasty who had been randomised to either having a drain for 24 hours or not having a drain. All patients followed standardised pre-, intra-, and post-operative regimes and were independently assessed using the Harris hip score before operation and at six, 18 and 36 months follow-up. The rate of superficial and deep infection was 2.9% and 0.4%, respectively, in the drained group and 4.8% and 0.7%, respectively in the undrained group. One patient in the undrained group had a haematoma which did not require drainage or transfusion. The rate of transfusion after operation in the drained group was significantly higher than for undrained procedures (p < 0.042). The use of a drain did not influence the post-operative levels of haemoglobin, the revision rates, Harris hip scores, the length of hospital stay or the incidence of thromboembolism. We conclude that drains provide no clear advantage at total hip arthroplasty, represent an additional cost, and expose patients to a higher risk of transfusion.

Erythropoietin is an effective clinical modality for reducing RBC transfusion in joint surgery

PURPOSE

Efficacy trials of preoperative erythropoietin therapy (PET) recommend a dosing schedule that cannot always be adhered to in everyday clinical practice. Consequently, we instituted a flexible dosing schedule and routinely offered it to anemic patients [hemoglobin (Hb)] < or = 130 g x L(-1)) undergoing total joint arthroplasty (TJA). The purpose of this observational, cohort study was to assess the effectiveness of this practice in reducing red blood cell (RBC) transfusion.

METHODS

After obtaining Institutional Ethics Board approval, data were collected prospectively on all patients who underwent TJA at our institution from July 1999 to June 2003. Patients with baseline Hb < or = 130 g x L(-1) were offered PET as follows: one to three sc injections (20,000 IU for those < or = 70 kg, and 40,000 IU for those > 70 kg) every three to seven days before surgery. Since treatment was not randomly assigned, multivariable logistic regression analysis and propensity score case-control matching were used to adjust for baseline differences in patient demographics and perioperative risk factors for RBC transfusion. The adjusted relationship between PET and RBC transfusion was then determined.

RESULTS

Of the 1,782 patients that underwent TJA during the study period, 770 (47.9%) had a Hb < 130 g x L(-1). Of these patients, 214 received PET and their RBC transfusion rate was 16.4%, whereas the transfusion rate was 56.1% in those who did not receive PET (P < 0.0001). The adjusted odds ratio of RBC transfusion with PET was 0.33 (95% confidence interval = 0.21-0.49).

CONCLUSION

PET, used as part of routine clinical practice, is an effective blood conservation modality.

Blood management: issues and options

Blood management in the perioperative period of the total joint arthroplasty procedure has evolved over the last 3 decades. Strategies have changed and are changing based on a better understanding of blood loss and blood replacement options in this patient population. Patient-specific options based on preoperative hemoglobin levels and patient comorbidities as well as anticipated blood loss have been developed and studied. Patient-specific blood management programs have provided cost-efficient care with low morbidity.

Preoperative erythropoietin in spine surgery

Spine surgery may be associated with profuse intraoperative bleeding that often requires blood transfusions. In recent years several techniques have been developed to avoid allogenic transfusions and their potential complications to surgical patients. In this study we review and analyse the role of preoperative recombinant human erythropoietin (rHuEPO) administration in spine surgery as a blood conservation strategy. Between 1998 and 2002, a total of 250 patients scheduled for spine surgery were included in our blood-sparing program: 114 patients (group 1), operated on before rHuEPO approval (2000), underwent preoperative autologous blood donation (ABD) alone, and 136 patients operated on after rHuEPO approval (groups 2 and 3) received rHuEPO while undergoing ABD. Adding rHuEPO to ABD resulted in higher haemoglobin and haematocrit values the day of surgery, more ABD units retrieved per patient and, consequently, reduced allogenic transfusion requirements. The effectiveness of rHuEPO as the only preoperative blood conservation technique was evaluated in ten patients with a predicted blood loss of less than 30% of their total volume, scheduled for lumbar surgery. Data from these patients were matched with those from a similar group of patients who had undergone ABD. Patients receiving rHuEPO alone had higher haemoglobin levels the day of surgery than did patients in the ABD program. Neither group required allogenic transfusions.

CONCLUSIONS

preoperative rHuEPO is useful for reducing allogenic blood requirements in elective spine surgery. In patients with an expected blood loss of around 50% of blood volume, rHuEPO improves ABD, minimising preoperative anaemia and increasing the number of ABD units collected. In patients with expected blood loss below 30% of total volume, rHuEPO administration may replace ABD.

Predicting Allogeneic Blood Transfusion Use in Total Joint Arthroplasty

Total joint arthroplasty (TJA) patients often receive allogeneic blood transfusion. In this study we sought to create and validate a clinical prediction rule for transfusion in TJA using data that are easily available when scheduling the procedure. Logistic regression modeling was applied to retrospective data from all TJA procedures performed in Edmonton, Alberta in 2000 (n = 1875). The area under the receiver operating curve for the resulting model in the training and validation data sets was 0.80 and 0.76 respectively. By assigning a simple score based on six independent predictors (age, gender, weight, hemoglobin, ASA operative risk classification and whether revision surgery was planned), it was possible to classify a given subject's risk of receiving allogeneic transfusion. We conclude that accurate prediction of transfusion risk in TJA is possible using a rule based on simple preoperative clinical and laboratory data. Such prediction could allow transfusion prevention strategies to be applied selectively to those at greatest risk.

Risks associated with blood transfusion after total knee arthroplasty

A retrospective study of 1,402 patients who underwent primary total knee arthroplasty (TKA) (1,194 unilateral, 208 bilateral) was performed. The strongest predictors for allogenic transfusion after surgery were advancing age (P<.001), low preoperative hemoglobin (P<.001), and the use of low-molecular-weight heparin postoperatively (P<.01). Pre-donation of 1 unit of autologous blood before TKA decreased the allogenic transfusion rate from a baseline of 38% to 11%, whereas pre-donating 2 units lowered the rate of breakthrough transfusion of allogenic blood to 7%. A patient with a preoperative hemoglobin >150 g/L or who is younger than age 65 with a preoperative hemoglobin >130 g/L may not benefit from pre-donation, and a high rate of wastage may result.

Reduction of blood transfusion rates in unilateral total knee arthroplasty by the introduction of a simple blood transfusion protocol

We prospectively studied blood transfusion practices within a single institution before and after the introduction of a blood transfusion protocol in consecutive patients undergoing unilateral total knee arthroplasty. Data were collected on 393 patients (group I) prior to and 295 patients (group II) after the introduction of the protocol. Following the introduction of the protocol, patients with preoperative haemoglobin of less than 11 g/dl were cross-matched prior to surgery. The criterion for postoperative transfusion was postoperative haemoglobin of less than 8.5 g/dl or a symptomatic patient with haemoglobin of greater than 8.5 g/dl. This change in practice reduced the transfusion rates from 31% in group I to 11.9% in group II. It reduced the non-utilisation of blood from 64 to 1%. There were no adverse outcomes related to the introduction of the protocol.

The use of Epoetin alfa in complex spine deformity surgery

STUDY DESIGN

A prospective, randomized trial comparing Epoetin alfa (Procrit) with placebo saline injection to determine effectiveness in increasing erythropoietic recovery in complex spine deformity surgery.

OBJECTIVES

To determine if Epoetin alfa can allow preoperative autologous donation completion more effectively and reduce perioperative homologous blood transfusion.

SUMMARY OF BACKGROUND DATA

The use of Epoetin alfa has been studied, primarily in the arthroplasty literature, for its effectiveness in decreasing transfusion requirements and increasing hemoglobin levels. It has not been studied in patients undergoing complex spine deformity surgery.

METHODS

A total of 48 patients were prospectively randomized into an Epoetin alfa group and a control group. All patients attempted to donate 4 units of preoperative autologous donation at weekly intervals; 40,000 units of Epoetin alfa were injected subcutaneously at the time of preoperative autologous donation in the Epoetin alfa group. Hematocrit levels were recorded weekly during the donation process and daily in the preoperative period.

RESULTS

Preoperative autologous donation was completed more effectively in the patients receiving Epoetin alfa. Epoetin alfa resulted in statistically higher hematocrit levels during preoperative autologous donation and perioperatively (P < 0.005). Homologous transfusion was decreased by 2.4 units and hospital stay was 1.8 days shorter in patients receiving Epoetin alfa.

CONCLUSION

Patients who received Epoetin alfa were able to complete preoperative autologous donation more effectively, increase erythropoietic recovery, decrease homologous transfusion requirements, and had shorter hospital stays.

Perioperative use of erythropoietin

Erythropoietin (EPO) is the primary regulator of red blood cell (RBC) production, and hypoxia is the main stimulus for EPO secretion. Increases in circulating levels of EPO are proportionate to the levels of tissue hypoxia, which are influenced by hematocrit (HCT). Small decreases in HCT as would be typical after presurgical autologous blood donation often do not result in increased EPO levels or in compensatory erythropoiesis. Erythropoiesis may also be limited by deficiencies of vitamin B(12), folate, and, most commonly, iron. The preoperative administration of EPO is effective in increasing erythrocyte mass and autologous donation volumes while maintaining higher HCT levels. In some surgical populations, particularly those individuals who experience surgical blood losses in excess of 2 L, EPO treatment also reduces allogeneic blood exposure. This effect is prominent in patients with a low initial HCT. Current assessments of the cost-effectiveness of EPO suggest that it achieves little overall improvement in patient health and that what improvement it does offer, it does at enormous cost.

Value of preoperative coagulation tests: reappraisal of major noncardiac surgery

In a retrospective case-control review, we evaluated preoperative coagulation testing in patients undergoing major noncardiac operations to determine if routine testing benefits this group of patients. The platelet count (PC), prothrombin time (PT), and activated partial thromboplastin time (aPTT) in all patients undergoing major noncardiac surgery over a 22-month period were reviewed. The review was done both manually and by the computerized hospital information system. Major surgery was defined as procedures usually associated with significant bleeding. For each patient with abnormal results, another two control patients undergoing the same surgery and matched for age and gender were identified. Case and control patients were compared regarding a change in the management plan, use of blood products, blood loss, and bleeding complications by detailed chart review. A total of 828 patients undergoing nine different surgeries were reviewed. The incidence of abnormal PCs was 2.2% [95% confidence interval (CI) 1.2-3.2%] and that of abnormal PT/aPTTs was 2.1% (95% CI 1.1-3.1%). There were only two cases each of thrombocytopenia and prolonged PT/aPTT where the coagulation tests were not indicated clinically. Although (compared to controls) patients with abnormal tests had more changes in their anesthesia plan (36% vs. 2%, p < 0.001) and platelet or fresh frozen plasma transfusions (50% vs. 9%, p < 0.001), blood loss and the incidence of bleeding complications were not different. We conclude that the use of preoperative coagulation tests in patients undergoing major noncardiac surgery should still be guided by clinical assessment. The surgical procedure itself does not constitute an indication for testing.

Preoperative administration of epoetin alfa to total joint arthroplasty patients

Epoetin alfa is indicated to reduce allogeneic transfusions in patients undergoing major operations. This study included 40 patients undergoing total joint arthroplasty who received 600 IU/kg doses of epoetin alfa 21, 14, and 7 days preoperatively. Statistically equal matches were obtained according to preoperative hemoglobin, operation, sex, and age. After controlling for autologous donation, the average hemoglobin level on postoperative day one in the treatment group (10.93 g/dL) was significantly higher than the matched patient group (9.86 g/dL). Likewise, treated patients were transfused with significantly less blood (0.68 units/patient) compared to the matched group (1.6 units/patient). In these patients, administration of epoetin alfa was associated with significantly higher perioperative hemoglobin levels and significantly fewer transfusions than matched counterparts. The use of epoetin alfa in this heterogeneous surgical population illustrates its success in a varied population.