Predictive factors for homologous transfusion during paediatric scoliosis surgery

The association between intraoperative fluid management and perioperative allogenic blood transfusion during adolescent idiopathic scoliosis surgery

INTRODUCTION

Bleeding and transfusion remain important concerns during surgical correction of scoliosis even when multiple conservative strategies, such as preoperative recombinant erythropoietin and/or antifibrinolytic agents, are used. The current work aimed to determine the impact of other potential risk factors, especially the volume of intraoperative fluid intake, on the perioperative risk of allogenic transfusion during surgical correction of adolescent idiopathic scoliosis.

METHODS

This prospective study included all cases of adolescent idiopathic scoliosis operated in a single center during 2 years (2018-2020). Predictors analyzed were as follows: body mass index, preoperative hemoglobin concentration, thoracoplasty, preoperative halo-gravity, volume of intraoperative crystalloid administration, use of esophageal Doppler (for goal-directed fluid therapy), and duration of surgery. Statistical analyses were performed using a multivariable logistic regression model.

RESULTS

Two hundred patients were included in the analysis. Multivariable analysis found: an increased volume of intraoperative crystalloid administration as a significant predictor of allogenic blood transfusion. Receiving operator characteristics analysis found the model exhibiting an area under the curve of 0.85 (95% confidence interval: 0.75-0.95). Optimizing stroke volume using esophageal Doppler was associated with a decrease in intraoperative crystalloid intake.

CONCLUSION

These results indicate a statistical association between the increase in crystalloid intake and the risk of allogenic blood transfusion during surgical correction of adolescent idiopathic scoliosis. Controlled studies are needed to address the causative relation between intraoperative fluid intake and the risk of allogenic transfusion.

Allogeneic Red Blood Cell Transfusion and Infectious Complications Following Pediatric Spinal Fusion: NSQIP-P Analysis

Substantial bleeding occurs during spinal fusion surgery in the pediatric population, and many patients receive allogeneic red blood cell transfusion (ARBT) for the treatment of resulting perioperative anemia. ARBT is thought to increase vulnerability to postoperative infections following major surgical procedures, but studies of this relationship in children undergoing spinal fusion have yielded conflicting results.

Development of a preoperative risk score predicting allogeneic red blood cell transfusion in children undergoing spinal fusion

BACKGROUND

Children undergoing spinal fusion often receive blood products. The goal of this study was to develop a preoperative score to help physicians identify those who are at risk of allogeneic red blood cell (RBC) transfusion.

STUDY DESIGN AND METHODS

This retrospective study of children undergoing spinal fusion in the ACS-NSQIP Pediatric database (2016-2019) aimed at identifying risk factors associated with allogeneic RBC transfusion. Univariable logistic regression and multivariable logistic regression were performed using preoperative patient characteristics and aided in the creation of a simplified scoring system.

RESULTS

Out of 13,929 total patients, 2990 (21.5%) were transfused. We created a risk score based on 10 independent predictors of transfusion: age, sex, race, weight < 3rd percentile, American Society of Anesthesiologists physical status classification, cardiac risk factors, hematologic disease, preoperative anemia, deformity type, and number of spinal levels to be fused. Patients in both the training and testing cohorts were assigned a score ranging from 0 (lowest risk) to 21 (highest risk). The developed transfusion risk score showed 77% accuracy in distinguishing patients who did not receive a transfusion during or soon after surgery (AUROC 0.7736 [95% CI, 0.7619-0.7852]) in the training cohort and 77% accuracy (AUROC 0.7732 [95% CI, 0.7554-0.7910]) in the testing cohort.

DISCUSSION

Our score, based on routinely available preoperative data, accurately estimates the risk of allogeneic RBC transfusion in pediatric patients undergoing spinal fusion. Future studies will inform whether patient blood management interventions targeted to high-risk patients can help reduce the need for transfusion and improve outcomes.

Risk factors for blood transfusion in adolescent patients with scoliosis undergoing scoliosis surgery: a study of 722 cases in a single center

Background

To assess the risk factors for blood transfusion in a great number of adolescent cases with different types of scoliosis who received scoliosis surgery.

Methods

Data of patients who were diagnosed as scoliosis and received one-stage posterior correction and spinal fusion from January 2014 to December 2017 were prospectively collected and retrospectively analyzed. Patients’ demographic characteristics, segments of spinal fusion, Cobb angle of the major curve,osteotomy pattern, preoperative and postoperative levels of hemoglobin, and allogeneic blood transfusion (ABT) were recorded and analyzed.

Results

In this study, 722 cases with adolescent scoliosis were included, of whom 32.8% (237/722) received ABT. Risk factors included diagnosis: neurofibromatosis (OR = 5.592), syndromic (OR = 3.029),osteotomy: Ponte osteotomy (OR = 5.997), hemivertebrae resection (OR = 29.171), pedicle subtraction osteotomy (PSO)(OR = 8.712), vertebral column resection (VCR)(OR = 32.265);fusion segments (OR = 1.224) and intraoperative blood loss (OR = 1.004). In the subgroup analysis of cases with idiopathic scoliosis, Ponte osteotomy (OR = 6.086), length of segments of spinal fusion (OR = 1.293), and intraoperative blood loss (OR = 1.001) were found as risk factors for ABT. Results of receiver operating characteristic (ROC) curve analysis revealed that length of segments of spinal fusion equal to 11.5 vertebrae was the best cutoff value for cases with idiopathic scoliosis who did not receive osteotomy in both ABT group and non-ABT group. In the subgroup analysis of congenital scoliosis, Ponte osteotomy (OR = 5.087), hemivertebra resection (OR = 5.457), PSO (OR = 4.055), VCR (OR = 6.940), and intraoperative blood loss (OR = 1.004) were risk factors for ABT.

Conclusions

Method of diagnosis, osteotomy pattern, segments of spinal fusion, and intraoperative blood loss were risk factors for ABT in cases with adolescent scoliosis. In cases with idiopathic scoliosis, Ponte osteotomy and segments of spinal fusion longer than 11.5 vertebrae were risk factors for ABT. In cases with congenital scoliosis, osteotomy pattern was the main risk factor for ABT.

Level of evidence

Level III.

Enhanced recovery after surgical correction of adolescent idiopathic scoliosis

BACKGROUND

Few publications in the literature examine enhanced recovery after scoliosis surgery (ERAS) in children, despite significant scientific interest in adults. The objective of the current study was to describe an ERAS protocol for surgical correction of adolescent idiopathic scoliosis (AIS) and its results.

METHODS

ERAS outcomes were measured in two patient cohorts. Historical controls and ERAS groups were selected from patients managed for scoliosis surgery in 2015 and 2018, respectively. The ERAS protocol included fasting minimization, carbohydrate loading, the avoidance of background morphine infusions, perioperative opioid-sparing protocols, the use of a cooling brace, early physiotherapy, feeding and oral medications, and the early removal of urinary catheters and surgical drains. The main outcome of the study was hospital length of stay.

RESULTS

Overall, 82 controls and 81 ERAS patients were recruited. ERAS protocols were observed in over 80% of patients for almost items. Median length of hospital stay was significantly lower in the ERAS group (- 3 [95% confidence interval: -2; -4] days). Median morphine consumption was reduced by 25% and 35% on days 2 and 3, respectively. The incidence of PONV did not differ between the two groups, and the incidence of constipation decreased slightly but significantly in the ERAS group on day 2. Pain intensity at rest and movement were lower in the ERAS group at day 2 and 3.

CONCLUSIONS

The current study suggests an ERAS protocol after adolescent idiopathic scoliosis surgery is associated with reduced hospital length of stay and improved postoperative care.

The incidence and risk factors for perioperative allogeneic blood transfusion in primary idiopathic scoliosis surgery

STUDY DESIGN

Case-control study.

OBJECTIVES

Evaluate the rate and risk factors for perioperative allogeneic blood transfusion (ABT) in primary idiopathic scoliosis surgery at a single institution. Avoiding perioperative ABT is ideal as transfusions are associated with adverse reactions, increased rates of infection, prolonged hospitalization, additional laboratory testing, and increased cost. Risk factors identified in other studies have differed, and to our knowledge, few studies have identified clinical strategies to predict patients at high risk for ABT.

METHODS

We reviewed 402 idiopathic scoliosis patients who underwent primary posterior spinal fusion and instrumentation (PSFI) at a single institution from 2015 to 2017. Medical records and radiographs were reviewed for all patients. Transfused patients were compared to the remaining cohort to find significant differences and identify predictors of higher ABT risk.

RESULTS

ABT occurred in 73 patients (18.2%), with the majority of transfusions occurring intraoperatively (41%) or postoperatively on the day of surgery (25%). The seven surgeons involved varied significantly in incidence of ABT (2.4-35.8%, p = 0.002). Patients who had ABT were younger (13.3 vs. 14.1 years, p < 0.01), had lower BMI (48th vs. 61st percentile, p < 0.001), and lower preoperative hemoglobin (13.1 vs. 13.7 g/dL, p < 0.01). Greater preoperative major Cobb angle (69° vs. 61.5°, p < 0.001), number of fusion levels (11.8 vs. 10.3, p < 0.001), and estimated blood loss (770 vs. 448 mL, p < 0.001) also predicted ABT.

CONCLUSIONS

ABT was associated with several risk factors, five of which are known preoperatively. Surgeons can use knowledge of these risk factors to assess transfusion risk preoperatively and plan surgery, blood management, and laboratory testing accordingly. The development of best practices for ordering ABT is possible given the variation amongst providers.

LEVEL OF EVIDENCE

Level III.

What Factors can Influence Massive Blood Loss in the Surgical Treatment of Neuromuscular Scoliosis?

Objective  The aim of the present study is to identify the incidence, predisposing factors and prognostic impact of blood loss in patients with neuromuscular scoliosis submitted to corrective surgery. Methods  Retrospective cohort study, including pediatric patients diagnosed with neuromuscular scoliosis undergoing instrumentation and posterior vertebral fusion in a university hospital. Patient characteristics were collected from the hospital information system. Results  A total of 39 patients were included in the study. The intraoperative blood losses were 962 ml, representing a loss of 35.63% of the blood volume. In 20 cases, there was a massive blood loss (> 30%) and only 7 patients did not need a transfusion. The group of patients with massive blood loss had a slightly higher age (13.75 versus 13.53 years old), a lower body mass index (BMI) percentile (25 versus 50), and for each decrease of 0.38 in the BMI, intraoperative blood losses increased 1% ( p  < 0.05). The value of preoperative albumin had influence on the percentage of blood loss, and for each decrease of 0.4 of albumin, blood loss increased 1% ( p  < 0.05). Conclusions  The factors that most contributed to the differences in blood loss were age, BMI, and preoperative albumin value. There was no significant association between Cobb angle, number of fusion levels and duration of surgery. We can conclude that these patients would benefit from preoperative nutritional control.

Coagulative function assessed preoperatively via the clot formation and lysis assay as a prognostic factor for blood loss in adolescents undergoing posterior spinal fusion for idiopathic scoliosis

BACKGROUND

Posterior spinal fusion for adolescent idiopathic scoliosis is a complex surgery often associated with clinically significant blood loss leading to perioperative blood transfusion. Knowledge of risk factors for blood loss and transfusion stems mostly from retrospective studies.

AIM

We sought to prospectively investigate putative prognostic factors for intraoperative blood loss and perioperative blood transfusion in adolescent idiopathic scoliosis patients undergoing posterior spine fusion, including clinical characteristics, surgical factors, and preoperative assessment of overall coagulative and fibrinolytic functions in plasma using the clot formation and lysis (CloFAL) assay.

METHODS

Following Internal Review Board approval, adolescents 10 to <21 years old with idiopathic scoliosis undergoing posterior spine fusion were enrolled preoperatively in a single-institutional prospective cohort and biobanking study. Clinical data were collected on patient characteristics, surgical approach, perioperative management, intraoperative estimated blood loss, and blood transfusion through hospital discharge. Coagulative and fibrinolytic functions in plasma were measured on preoperative samples by CloFAL assay (Coagulation Index and modified Fibrinolytic Index). Univariate linear regression and multivariable linear regression were performed to identify predictors of weight-indexed intraoperative estimated blood loss EBL (EBL/kg).

RESULTS

The final study population included 74 patients. Median age was 14.8 years (SD = 2.2). After adjustment for other putative prognostic factors via multivariable linear regression, coagulative function as determined preoperatively by CloFAL Coagulation Index was an independent predictor of intraoperative (EBL)/kg. Specifically, each 10% increase in CloFAL CI was associated with 3% decrease in the geometric mean of EBL/kg (OR 0.97, 95%CI 0.94-0.99, P = .01).

CONCLUSION

In adolescents undergoing posterior spinal fusion for idiopathic scoliosis, increased coagulative function measured preoperatively using the CloFAL assay is independently associated with decreased intraoperative blood loss. Future studies should expand upon these investigations of plasma coagulative and fibrinolytic capacities in combination with clinical factors, to guide precise preventive strategies against blood loss and blood transfusion in this patient population.

Development of a prediction model for allogenic blood transfusion in children undergoing surgery for developmental dysplasia of the hip

BACKGROUND

Blood transfusion is a common practice, but it is not without cost and risk. A model that predicts the risk of blood transfusion could guide informed preoperative blood ordering and use of blood loss preventive measures.

OBJECTIVE

This study aimed to develop a prediction model of blood transfusion in children with developmental dysplasia of the hip (DDH) undergoing surgery.

METHODS

A retrospective cohort of DDH patients from 2008 to 2017. The included patients were between 1 to 9 years old, underwent anterior open reduction and/or acetabular osteotomy with and without femoral shortening. The unit of analysis was undergoing such an operation. The outcome was allogenic blood transfusion. Potential predictors were age, sex, body mass index (BMI), international hip dysplasia institute grade, type of surgery, intervention bilaterally during the same operative session, primary versus reoperation surgery, the addition of regional anaesthesia, preoperative haemoglobin and hematocrit.

RESULTS

A total of 524 patients who met the inclusion criteria underwent 721 operative sessions. The median age (interquartile range) at operation was 23 (20-33) months. The blood transfusion rate was 11.8%. Independent predictors were lower preoperative haemoglobin, reduced BMI, simultaneous bilateral surgery and the extent of surgical treatment.

CONCLUSIONS

The developed prognostic model allows prediction for blood transfusion in DDH patients undergoing surgery.

Dilutional coagulopathy in pediatric scoliosis surgery: A single center report

BACKGROUND

Children undergoing posterior spinal fusion experience high blood loss often necessitating transfusion. An appropriately activated coagulation system provides hemostasis during surgery, but pathologic dysregulation can cause progressive bleeding and increased transfusions. Despite receiving antifibrinolytics for clot stabilization, many patients still require transfusions.

AIMS

We sought to examine the association of dilutional coagulopathy with blood loss and blood transfusion in posterior spinal fusion for pediatric scoliosis patients.

METHODS

A retrospective, single institution study of children undergoing posterior spinal fusion >6 levels with a standardized, prospective anesthetic protocol utilizing antifibrinolytics. Blood loss was evaluated using a hematocrit-based calculation. To evaluate transfusions, a normalized Blood Product Transfusion calculation was developed. Factors associated with blood loss and blood transfusions were determined by univariate analysis and multivariate regression modeling with multicollinearity and mediation analysis.

RESULTS

Patients received 73.7 mL/kg (standard deviation ±30.8) of fluid poor in coagulation factors. Estimated blood loss was 42.6 mL/kg (standard deviation ±18.0). There was a significant association between estimated blood loss and total fluids delivered (Spearman's rho = 0.51, 95% confidence interval 0.33-0.65, P < 0.001). Factors significantly associated with normalized Blood Product Transfusion in this cohort included age, weight, scoliosis type, levels fused, total osteotomies, pelvic fixation, total fluid, maximum prothrombin time, and minimum fibrinogen. Regression modeling showed the best combination of variables for modeling normalized Blood Product Transfusion included patient weight, number of levels fused, total fluid administered, and maximum prothrombin time.

CONCLUSION

Blood product transfusion remains a frustrating problem in pediatric scoliosis. Identifying and controlling dilutional coagulopathy in these patients may reduce blood loss and the need for blood transfusion.

Predictive Modeling for Blood Transfusion After Adult Spinal Deformity Surgery: A Tree-Based Machine Learning Approach

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

Blood transfusion is frequently necessary after adult spinal deformity (ASD) surgery. We sought to develop predictive models for blood transfusion after ASD surgery, utilizing both classification tree and random forest machine-learning approaches.

SUMMARY OF BACKGROUND DATA

Past models for transfusion risk among spine surgery patients are disadvantaged through use of single-institutional data, potentially limiting generalizability.

METHODS

This investigation was conducted utilizing the American College of Surgeons National Surgical Quality Improvement Program dataset years 2012 to 2015. Patients undergoing surgery for ASD were identified using primary-listed current procedural terminology codes. In total, 1029 patients were analyzed. The primary outcome measure was intra-/postoperative blood transfusion. Patients were divided into training (n = 824) and validation (n = 205) datasets. Single classification tree and random forest models were developed. Both models were tested on the validation dataset using area under the receiver operating characteristic curve (AUC), which was compared between models.

RESULTS

Overall, 46.5% (n = 479) of patients received a transfusion intraoperatively or within 72 hours postoperatively. The final classification tree model used operative duration, hematocrit, and weight, exhibiting AUC = 0.79 (95% confidence interval 0.73-0.85) on the validation set. The most influential variables in the random forest model were operative duration, surgical invasiveness, hematocrit, weight, and age. The random forest model exhibited AUC = 0.85 (95% confidence interval 0.80-0.90). The difference between the classification tree and random forest AUCs was nonsignificant at the validation cohort size of 205 patients (P = 0.1551).

CONCLUSION

This investigation produced tree-based machine-learning models of blood transfusion risk after ASD surgery. The random forest model offered very good predictive capability as measured by AUC. Our single classification tree model offered superior ease of implementation, but a lower AUC as compared to the random forest approach, although this difference was not statistically significant at the size of our validation cohort. Clinicians may choose to implement either of these models to predict blood transfusion among their patients. Furthermore, policy makers may use these models on a population-based level to assess predicted transfusion rates after ASD surgery.

LEVEL OF EVIDENCE

3.

Predicting massive transfusion in adolescent idiopathic scoliosis patients undergoing corrective surgery: Association of preoperative radiographic findings

Corrective surgery with a posterior approach for adolescent idiopathic scoliosis (AIS) is often accompanied by considerable bleeding. Massive transfusion after excessive hemorrhage is associated with complications such as hypothermia, coagulopathy, and acid-base imbalance. Therefore, prediction and prevention of massive transfusion are necessary to improve the clinical outcome of AIS patients. We aimed to identify the factors associated with massive transfusion in AIS patients undergoing corrective surgery. We also evaluated the clinical outcomes after massive transfusion.We included and analyzed AIS patients who underwent corrective surgery with a posterior approach from January 2008 to February 2015. We retrospectively reviewed the electronic medical records of 765 consecutive patients. We performed multivariable logistic regression analysis to assess the factors related to massive transfusion. Furthermore, we compared the effects of massive transfusion on clinical outcomes, including postoperative morbidity and hospital stay.Of 765 patients, 74 (9.7%) received massive transfusion. Body mass index (odds ratio [OR] 0.782, 95% confidence interval [CI] 0.691-0.885, P < .001) and the number of fused vertebrae (OR 1.322, 95% CI 1.027-1.703, P = .03) were associated with massive transfusion. In the comparison among the different Lenke curve types, Lenke type 4 showed the highest prevalence of massive transfusion. Patients in the massive transfusion group showed a higher incidence rate of postoperative morbidity and prolonged hospital stay.Massive transfusion was required in 9.7% of AIS patients who underwent corrective surgery with a posterior approach. A lower body mass index and higher number of fused vertebrae were associated with massive transfusion. Massive transfusion is related to poor clinical outcomes in AIS patients.

Predictors of chronic neuropathic pain after scoliosis surgery in children

Background

Numerous publications describe chronic pain following surgery in both adults and children. However, data in the paediatric population are still sparse and both prevalence of chronic pain after surgery and risk factors of this complication still undetermined.

Methods

We prospectively evaluated the prevalence of chronic pain and its neuropathic pain component at 1 year following correction of idiopathic scoliosis in children less than 18 years of age. Pain was defined as the presence of pain (numerical rating scale – NRS ≥4), the presence of signs of neurologic damage within the area of surgery and the presence of the neuropathic symptoms as a DN4 (Douleur Neuropathique 4) questionnaire ≥4. Factors investigated as potentially associated with the presence of a persistent neuropathic pain were: age, weight, the presence of continuous preoperative pain over the 3 months before surgery, surgical characteristics, pain scores during the first five postoperative days, and DN4 at day 3. Statistical analysis employed univariate analysis and a multivariate logistic regression model.

Results

Thirty six patients were included in the study. Nineteen (52.8%) had pain at one year after surgery. Among them 17 (48.2%) had neuropathic pain. Logistic regression found continuous pain over the 3 months preceding surgery and day 1 morphine consumption ≥0.5 mg kg-1 as independent predictors of persistent chronic pain with a neuropathic component. The overall model accuracy was 80.6 and the area under the curve of the model was 0.89 (95% confidence interval 0.78–0.99).

Conclusions

The present study found a high proportion of paediatric patients developing chronic persistent pain after surgical correction of scoliosis diformity. It allows identifying two factors associated with the occurrence of persistent chronic pain with a neuropathic component: the presence of persistent preoperative pain during the 3 months preceeding surgery and postoperative opioid consumption at day 1 –;0.5 mg kg-1

Implication

Patients scheduled for spine surgery and presenting with preoperative pain should be considered at risk of chronic pain after surgery and managed accordingly by the chronic and/or acute pain team. Postoperative opioid consumption should be lowered as possible by using multimodal analgesia and regional analgesia such as postoperative epidural analgesia.

Predictive factors of intraoperative cell salvage during pediatric scoliosis surgery. Cell saver during scoliosis surgery in children

INTRODUCTION

Blood-saving strategy during spinal surgery in children often includes recombinant erythropoietin (rEPO) and antifibrinolytic therapapy (AFT). The aim of this study was to investigate the efficacy of intraoperative blood salvage in decreasing homologous blood transfusion.

MATERIAL AND METHODS

Using the prospective data from patients operated during a one year period for scoliosis correction, we calculate the predictable hematocrit at day postoperative 1 without the use of blood salvage and compare it to the target hematocrit transfusion according to patient's status. Predictors analyzed were: age, weight, surgical indication, Cobb's angle, ASA status, preoperative hemoglobin, number of level fused, sacral fusion and thoracoplasty. Statistical analyses were performed using a classification tree analysis.

RESULTS

This study included 147 patients. Blood salvage was estimated avoiding homologous blood transfusion in 17 patients. Predictors of the efficacy of blood salvage were: neuromuscular indications, number of level fused and BMI. Blood salvage was found totally ineffective in: patients with no neuromuscular diseases with either: surgeries interesting<13 levels fused or surgeries interesting>13 levels with a preoperative BMI ≥ 21. In all other cases, blood salvage can decrease homologous transfusion. The model exhibited 97% of accurate for the prediction if the inefficacy of blood salvage. The AUCROC of the model was 0.93 [95% confidence interval 0.9 to 0.99] and the overall validation was 60.1% of explained variability.

CONCLUSION

The present study indicates that blood salvage is ineffective under certain circumstances. More studies are mandatory to confirm these results.

Blood transfusion in the surgical treatment of adolescent idiopathic scoliosis-a single-center experience of patient blood management in 210 cases

BACKGROUND

The surgical treatment of adolescent idiopathic scoliosis can be associated with substantial blood loss, requiring allogeneic red blood cell (RBC) transfusion. This study describes the use of RBC and the effect of a standardized perioperative patient blood management program.

STUDY DESIGN AND METHODS

Patients treated with posterior instrumented fusion were consecutively enrolled over a 6-year period. Patient blood management strategies were implemented in 2011, including prophylactic tranexamic acid, intraoperative permissive hypotension, restrictive fluid therapy (including avoidance of synthetic colloids), restrictive RBC trigger according to institutional standardized protocol, the use of cell savage, and goal-directed therapy according to thrombelastography.

RESULTS

In total, 210 patients were included. 64 patients (31%) received RBC transfusions. A decline in the intraoperative rate of RBC transfusion was observed, from 77% in 2011 to 13% in 2016 (p < 0.001). Patients in the transfusion group had a significantly larger major curve, lower preoperative hemoglobin, higher estimated blood loss, and an increased use of crystalloid volume resuscitation. Multiple logistic regression showed that significant predictors for RBC transfusion were preoperative hemoglobin level (odds ratio [OR], 0.40; 95% confidence interval [CI], 0.27-0.57), estimated blood loss (OR, 1.26; 95% CI, 1.15-1.42), and year of surgery (indicating the effect of patient blood management) (OR per year, 0.76; 95% CI, 0.58-0.99).

CONCLUSION

A perioperative patient blood management program substantially reduced the need for RBC transfusion. A preoperative evaluation of anemia is essential to further minimize transfusion rates.