Autologous blood transfusion in the United States: clinical and nonclinical determinants of use

State and Government Administrative Databases: Medicare, National Inpatient Sample (NIS), and State Inpatient Databases (SID) Programs

The availability of large state and federally run administrative health-care databases provides potentially comprehensive population-wide information that can dramatically impact both medical and health-policy decision-making. Specific opportunities and important limitations exist with all administrative databases based on what information is collected and how reliably specific data elements are reported. Access to patient identifiable-level information can be critical for certain long-term outcome studies but can be difficult (although not impossible) due to patient privacy protections, while more easily available de-identified information can provide important insights that may be more than sufficient for some short-term operative or in-hospital outcome questions. The first section of this paper by Sarah K. Meier and Benjamin D. Pollock discusses Medicare and the different data files available to health-care researchers. They describe what is and is not generally available from even the most granular Medicare Standard Analytic Files, and provide an analysis of the strengths and weaknesses of Medicare administrative data as well as the resulting best and inappropriate uses of these data. In the second section, the Nationwide Inpatient Sample and complementary State Inpatient Database programs are reviewed by Steven M. Kurtz and Edmund Lau, with insights into the origins of these programs, the data elements that are recorded relating to the operative procedure and hospital stay, and examples of the types of studies that optimally utilize these data sources. They also detail the limitations of these databases and identify studies that they are not well-suited for, especially those involving linkage or longitudinal studies over time. Both sections provide useful guidance on the best uses and pitfalls related to these important large representative national administrative data sources.

Non-White Race/Ethnicity and Female Sex Are Associated with Increased Allogeneic Red Blood Cell Transfusion in Cardiac Surgery Patients: 2007-2018

OBJECTIVE

To evaluate racial and/or ethnic and sex disparities in allogeneic and autologous red blood cell (RBC) transfusions in cardiac surgery.

DESIGN

A retrospective observational study.

SETTING

2007 to 2018 data from FL, MD, KY, WA, NY, and CA from the State Inpatient Databases (SID), Healthcare Cost and Utilization Project (HCUP), Agency for Healthcare Research and Quality.

PARTICIPANTS

A total of 710,296 inpatients who underwent elective or emergency coronary artery bypass grafting (CABG), cardiac valve surgery,or combination CABG and/or valve surgery.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Patients were cohorted by race and/or ethnicity and sex, as defined by SID-HCUP. Demographic characteristics and comorbidities were compared. Rates and risk-adjusted odds ratios (aOR) were calculated for allogeneic and autologous RBC transfusion (primary outcomes). Additional secondary analyses were conducted for in-hospital mortality, 30-day readmission, 90-day readmission, hospital length of stay, and total charges to examine the effect of RBC transfusion status. Effect modification between race and sex was assessed. When controlling for patient demographics, comorbidities, and hospital characteristics, non-White patients were more likely to receive an allogeneic RBC transfusion during cardiac surgery than White patients (Black: aOR 1.17, 99% CI 1.13-1.20, p < 0.001, Hispanic: aOR 1.22, 99% CI 1.19-1.22, p < 0.001). Women were more likely to receive allogeneic RBC than men (aOR 1.69, 99% CI 1.66-1.72, p < 0.001). In interaction models, non-White women had the highest odds of allogeneic blood transfusion as compared to White men (reference category; Black women: aOR 2.04, 99% CI 1.91-2.17, p < 0.001, Hispanic women: aOR 2.03, 99% CI 1.90-2.16, p < 0.001).

CONCLUSION

These findings highlighted the differences in the rates of allogeneic RBC transfusion for non-White and female patients undergoing cardiac surgery, which is a well-established marker of poorer outcomes.

Establishment and assessment of a nomogram for predicting blood transfusion risk in posterior lumbar spinal fusion

Background

The aim of this study was to determine the risk factors and develop a nomogram for blood transfusions after posterior lumbar spinal fusion (PSL).

Methods

We conducted a retrospective, single-center study based on 885 patients receiving PSL, and data was obtained from May 2015 to September 2019. Univariable and multivariable logistics regression analysis were conducted to identify risk factors for blood transfusion, and a nomogram was constructed to individually evaluate the risk of blood transfusion. Discrimination, calibration, and clinical usefulness were validated by the receiver operating characteristics (ROC), C-index, calibration plot, and decision curve analysis, respectively. Bootstrapping validation was performed to assess the performance of the model.

Results

Of 885 patients, 885 were enrolled in the final study population, and 289 received blood transfusion. Statistical analyses showed that low preoperative hemoglobin (Hb), longer time to surgery, operative time, levels of fusion > 1, longer surgery duration, and higher total intraoperative blood loss (IBL) were the risk factors for transfusion. The C-index was 0.898 (95% CI 0.847–0.949) in this dataset and 0.895 in bootstrapping validation, respectively. Calibration curve showed satisfied discrimination and calibration of the nomogram. Decision curve analysis (DCA) shown that the nomogram was clinical utility.

Conclusions

In summary, we investigated the relationship between the blood transfusion requirement and predictors: levels of fusion, operative time, time to surgery, total intraoperative EBL, and preoperative Hb level. Our nomogram with a robust performance in the assessment of risk of transfusion can contribute to clinicians in making clinical decision. However, external validation is still needed in the further.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-020-02053-2.

Impact of Preoperative Platelet Count on Bleeding Risk and Allogeneic Transfusion in Multilevel Spine Surgery

STUDY DESIGN

This was an observational cohort study of patients receiving multilevel thoracic and lumbar spine surgery.

OBJECTIVE

The aim of this study was to identify which patients are at high risk for allogeneic transfusion which may allow for better preoperative planning and employment of specific blood management strategies.

SUMMARY OF BACKGROUND DATA

Multilevel posterior spine surgery is associated with a significant risk for major blood loss, and allogeneic blood transfusion is common in spine surgery.

METHODS

A univariate logistic regression model was used to identify variables that were significantly associated with intraoperative allogeneic transfusion. A multivariate forward stepwise logistic regression model was then used to measure the adjusted association of these variables with intraoperative transfusion.

RESULTS

Multilevel thoracic and lumbar spine surgery was performed in 921 patients. When stratifying patients by preoperative platelet count, patients with pre-operative thrombocytopenia and severe thrombocytopenia had a significantly higher rate of transfusion than those who were not thrombocytopenic. Furthermore, those with severe thrombocytopenia had a higher rate of red blood cells, fresh frozen plasma, and platelet transfusion than those with higher platelet counts. Multivariate logistic regression found that preoperative platelet count was the most significant contributor to transfusion, with a platelet count ≤100 having an adjusted odds ratio (OR) of transfusion of 4.88 (95% confidence interval [CI] 1.58-15.02, P = 0.006). Similarly, a platelet count between 101and 150 also doubled the risk of transfusion with an adjusted OR of 2.02 (95% CI 1.01-4.04, P = 0.047). The American Society of Anesthesiologists classification score increased the OR of transfusion by 2.5 times (OR = 2.52, 95% CI 1.54-4.13), whereas preoperative prothrombin time and age minimally increased the risk.

CONCLUSION

Preoperative thrombocytopenia significantly contributes to intraoperative transfusion in multilevel thoracic lumbar spine surgery. Identifying factors that may increase the risk for transfusion could be of great benefit in better preoperative counseling of patients and in reducing overall cost and postoperative complications by implementing strategies and techniques to reduce blood loss and blood transfusions.

LEVEL OF EVIDENCE

2.

The risks, reasons, and costs for 30- and 90-day readmissions after fusion surgery for adolescent idiopathic scoliosis

OBJECTIVE

With the continued evolution of bundled payment plans, there has been a greater focus within orthopedic surgery on quality metrics up to 90 days of care. Although the Centers for Medicare and Medicaid Services does not currently penalize hospitals based on their pediatric readmission rates, it is important to understand the drivers for unplanned readmission to improve the quality of care and reduce costs.

METHODS

The National Readmission Database provides a nationally representative sample of all discharges from US hospitals and allows follow-up across hospitals up to 1 calendar year. Adolescents (age 10-18 years) who underwent idiopathic scoliosis surgery from 2012 to 2015 were included. Patients were separated into those with and those without readmission within 30 days or between 31 and 90 days. Demographics, operative conditions, hospital factors, and surgical outcomes were compared using the chi-square test and t-test. Independent predictors for readmissions were identified using stepwise multivariate logistic regression.

RESULTS

A total of 30,677 patients underwent adolescent idiopathic scoliosis surgery from 2012 to 2015. The rates of 30- and 90-day readmissions were 2.9% and 1.4%, respectively. The mean costs associated with the index admission and 30- and 90-day readmissions were $60,680, $23,567, and $16,916, respectively. Common risk factors for readmissions included length of stay > 5 days, obesity, neurological disorders, and chronic use of antiplatelets or anticoagulants. The index admission complications associated with readmissions were unintended durotomy, syndrome of inappropriate antidiuretic hormone, and superior mesenteric artery syndrome. Hospital factors, discharge disposition, and operative conditions appeared to be less important for readmission risk. The top reasons for 30-day and 90-day readmissions were wound infection (34.7%) and implant complications (17.3%), respectively. Readmissions requiring a reoperation were significantly higher for those that occurred between 31 and 90 days after the index readmission.

CONCLUSIONS

Readmission rates were low for both 30- and 90-day readmissions for adolescent idiopathic scoliosis surgery patients. Nevertheless, readmissions are costly and appear to be associated with potentially modifiable risk factors, although some risk factors remain potentially unavoidable.

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

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine whether type of intraoperative blood transfusion used is associated with increased incidence of postoperative delirium after complex spine fusion involving five levels or greater.

SUMMARY OF BACKGROUND DATA

Postoperative delirium after spine surgery has been associated with age, cognitive status, and several comorbidities. Intraoperative allogenic blood transfusions have previously been linked to greater complication risks and length of hospital stay. However, whether type of intraoperative blood transfusion used increases the risk for postoperative delirium after complex spinal fusion remains relatively unknown.

METHODS

The medical records of 130 adult (≥18 years old) spine deformity patients undergoing elective, primary complex spinal fusion (more than or equal to five levels) for deformity correction at a major academic institution from 2010 to 2015 were reviewed. We identified 104 patients who encountered an intraoperative blood transfusion. Of the 104, 15 (11.5%) had Allogenic-only, 23 (17.7%) had Autologous-only, and 66 (50.8%) had Combined transfusions. The primary outcome investigated was the rate of postoperative delirium.

RESULTS

There were significant differences in estimated blood loss (Combined: 2155.5 ± 1900.7 mL vs. Autologous: 1396.5 ± 790.0 mL vs. Allogenic: 1071.3 ± 577.8 mL vs. None: 506.9 ± 427.3 mL, P < 0.0001) and amount transfused (Combined: 1739.7 ± 1127.6 mL vs. Autologous: 465.7 ± 289.7 mL vs. Allogenic: 986.9 ± 512.9 mL, P < 0.0001). The Allogenic cohort had a significantly higher proportion of patients experiencing delirium (Combined: 7.6% vs. Autologous: 17.4% vs. Allogenic: 46.7% vs. None: 11.5%, P = 0.002). In multivariate nominal-logistic regression analysis, Allogenic (odds ratio [OR]: 24.81, 95% confidence interval [CI] [3.930, 156.702], P = 0.0002) and Autologous (OR: 6.43, 95% CI [1.156, 35.772], P = 0.0335) transfusions were independently associated with postoperative delirium.

CONCLUSION

Our study suggests that there may be an independent association between intraoperative autologous and allogenic blood transfusions and postoperative delirium after complex spinal fusion. Further studies are necessary to identify the physiological effect of blood transfusions to better overall patient care and reduce healthcare expenditures.

LEVEL OF EVIDENCE

3.

Predicting Perioperative Complications in Adult Spinal Deformity Surgery Using a Simple Sliding Scale

STUDY DESIGN

A retrospective database study.

OBJECTIVE

The aim of this study was to develop and validate a sliding scale for predicting perioperative complications associated with adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

ASD surgery can have high perioperative complication rates, which is associated with increased morbidity and mortality.

METHODS

Data on consecutive ASD patients undergoing posterior corrective surgery over a 6-year interval were collected from a prospective database. The patients' preoperative general condition, surgical status, and perioperative complications occurring within 30 days of surgery were analyzed and independent predictors were determined using multivariable logistic regression analysis. We made the sliding scale using cut-off values from receiver operating curve analysis and validated the performance of this model.

RESULTS

Three hundred four patients were included with a mean age of 62.9 years. One hundred eight patients (35.5%) were affected by at least one perioperative complication with a total of 195 perioperative complications, including neurological (12.8%), excessive blood loss (11.2%), delirium (11.2%), and infection (3.6%). Total independent predictors were age [odds ratio (OR): 1.042], operation time (OPT) (OR: 2.015), and estimated blood loss (EBL) (OR: 4.885) with cut-off values of approximately 70 years, 6 hours, and 2000 mL, respectively. Fusion of ≥10 segments (OR: 2.262), three-column osteotomy (OR: 1.860), current use of antihypertensive (OR: 2.595) and anticoagulant (OR: 7.013), and body mass index (OR: 1.160) were risk factors for neurological complications, infection, and deep vein thrombosis/pulmonary thrombosis. Our proposed sliding scale had a sensitivity of 91%, specificity of 58.1%, and the incidence of perioperative complication in the validation dataset was smaller than that without this scale (P ≤ 0.05).

CONCLUSION

Patients' age, current medication, and degenerative pathology might be independent preoperative as well as operative predictors. An age and comorbidities based sliding scale with classifications of OPT and EBL may be useful for risk prediction in ASD surgery.

LEVEL OF EVIDENCE

3.

Red Blood Cell Transfusion Need for Elective Primary Posterior Lumbar Fusion in A High-Volume Center for Spine Surgery

(1) Background: This study evaluated the perioperative red blood cell (RBC) transfusion need and determined predictors for transfusion in patients undergoing elective primary lumbar posterior spine fusion in a high-volume center for spine surgery. (2) Methods: Data from all patients undergoing spine surgery between 1 January 2014 and 31 December 2016 were reviewed. Patients’ demographics and comorbidities, perioperative laboratory results, and operative time were analyzed in relation to RBC transfusion. Multivariate logistic regression analysis was performed to identify the predictors of transfusion. (3) Results: A total of 874 elective surgeries for primary spine fusion were performed over the three years. Only 54 cases (6%) required RBC transfusion. Compared to the non-transfused patients, transfused patients were mainly female (p = 0.0008), significantly older, with a higher ASA grade (p = 0.0002), and with lower pre-surgery hemoglobin (HB) level and hematocrit (p < 0.0001). In the multivariate logistic regression, a lower pre-surgery HB (OR (95% CI) 2.84 (2.11–3.82)), a higher ASA class (1.77 (1.03–3.05)) and a longer operative time (1.02 (1.01–1.02)) were independently associated with RBC transfusion. (4) Conclusions: In the instance of elective surgery for primary posterior lumbar fusion in a high-volume center for spine surgery, the need for RBC transfusion is low. Factors anticipating transfusion should be taken into consideration in the patient’s pre-surgery preparation.

Predictors of Blood Transfusion in Posterior Lumbar Spinal Fusion: A Canadian Spine Outcome and Research Network Study

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To identify patient or procedure related predictors of postoperative blood transfusions in posterior lumbar fusion (PSF).

SUMMARY OF BACKGROUND DATA

The rate of PSF surgery has increased significantly. It remains the most common surgical procedure used to stabilize the spine; however, the impact of blood loss requiring blood transfusions remains a significant concern.

METHODS

Analysis of data from the Canadian Spine Outcomes and Research Network. Patients who underwent PSF between 2008 and 2015 were identified. Multivariate analysis was used to identify predictors of blood transfusion from the collected information.

RESULTS

Seven hundred seventy two patients have undergone PSF, 18% required blood transfusion, 54.8% were females and the mean age was 60 years. The analysis revealed five significant predictors: American Society of Anesthesiologist class (ASA), operative time, multilevel fusion, sacrum involvement, and open posterior approach. The odds of transfusion for those with ASA >1 were 6 times those with ASA1 (odds ratio [OR] 6.1, 95% confidence interval [CI] 1.4-27.1, P < 0.018). For each 60-minute increase in operative time, the odds of transfusion increased by 4.2% (OR 1.007, 95% CI 1.004-1.009, P < 0.001). The odds of transfusion were 6 times higher for multilevel fusion (OR 5.8, 95% CI 2.6-13.2, P < 0.001). Extending fusion to the sacrum showed 3 times higher odds for blood transfusion (OR 3.2, 95% CI 1.8-5.8, P < 0.001). The odds of transfusion for patients undergoing open approach were 12 times those who had minimal invasive surgery (OR 12.5, 95% CI 1.6-97.4, P < 0.016). Finally, patients receiving transfusions were more likely to have extended hospital stay.

CONCLUSION

ASA >1, prolonged operative time, multilevel fusion, sacrum involvement, and open posterior approach were significant predictors of blood transfusion in PSF.

LEVEL OF EVIDENCE

3.

Impact of Preoperative Anemia on Outcomes in Adults Undergoing Elective Posterior Cervical Fusion

STUDY DESIGN

Retrospective analysis of prospectively collected data.

OBJECTIVES

Few studies have investigated the role of preoperative anemia on postoperative outcomes of posterior cervical fusion. This study looked to investigate the potential relationship between preoperative anemia and postoperative outcomes following posterior cervical spine fusion.

METHODS

Data from patients undergoing elective posterior cervical fusions between 2005 and 2012 was collected from the American College of Surgeons National Surgical Quality Improvement Program database using inclusion/exclusion criteria. Multivariate analyses were used to identify the predictive power of anemia for postoperative outcomes.

RESULTS

A total of 473 adult patients undergoing elective posterior cervical fusions were identified with 106 (22.4%) diagnosed with anemia preoperatively. Anemic patients had higher rates of diabetes (P = .0001), American Society of Anesthesiologists scores ≥3 (P < .0001), and higher dependent functional status prior to surgery (P < .0001). Intraoperatively, anemic patients also had higher rates of neuromuscular injuries (P = .0303), stroke (P = .013), bleeding disorders (P = .0056), lower albumin (P < .0001), lower hematocrit (P < .0001), and higher international normalized ratio (P = .002). Postoperatively, anemic patients had higher rates of complications (P < .0001), death (P = .008), blood transfusion (P = .001), reoperation (P = .012), unplanned readmission (P = .022), and extended length of stay (>5 days; P < .0001).

CONCLUSIONS

Preoperative anemia is linked to a number of postoperative complications, which can increase length of hospital stay and increase the likelihood of reoperation. Identifying preoperative anemia may play a role in optimizing and minimizing the complication rates and severity of comorbidities following posterior cervical fusion.

Early Complications and Outcomes in Adult Spinal Deformity Surgery: An NSQIP Study Based on 5803 Patients

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

The purpose of this study is to determine the incidence, impact, and risk factors for short-term postoperative complications following elective adult spinal deformity (ASD) surgery.

METHODS

Current Procedural Terminology codes were used to query the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) for adults who underwent spinal deformity surgery from 2010 to 2014. Patients were separated into groups of those with and without complications. Univariate analysis and multivariate logistic regression were used to assess the impact of patient characteristics and operative features on postoperative outcomes.

RESULTS

In total, 5803 patients were identified as having undergone ASD surgery in the NSQIP database. The average patient age was 59.5 (±13.5) years, 59.0% were female, and 81.1% were of Caucasian race. The mean body mass index was 29.5(±6.6), with 41.9% of patients having a body mass index of 30 or higher. The most common comorbidities were hypertension requiring medication (54.5%), chronic obstructive pulmonary disease (4.9%), and bleeding disorders (1.2%). Nearly a half of the ASD patients had an operative time >4 hours. The posterior fusion approach was more common (56.9%) than an anterior one (39.6%). The mean total relative value unit was 73.4 (±28.8). Based on multivariate analyses, several patient and operative characteristics were found to be predictive of morbidity.

CONCLUSION

Surgical correction of ASD is associated with substantial risk of intraoperative and postoperative complications. Preoperative and intraoperative variables were associated with increased morbidity and mortality. This data may assist in developing future quality improvement activities and saving costs through measurable improvement in patient safety.

Thrombotic and Infectious Morbidity Are Associated with Transfusion in Posterior Spine Fusion

BACKGROUND

Although previous investigators have established an association between blood transfusion and adverse outcomes, the relative frequency of different morbid events and the association with transfusion dose are not well understood.

QUESTIONS/PURPOSES

The purpose of the study is to characterize the relationship between blood transfusion and different types of morbidity after posterior spine fusion.

METHODS

We retrospectively analyzed electronic medical records for 963 patients who underwent posterior spinal fusion surgery at a single institution, of which 603 (62.6%) received an allogeneic blood transfusion. Then, we assessed patient and surgical characteristics in a risk-adjusted fashion to identify various morbid event rates and independent predictors in these adverse outcomes.

RESULTS

Compared to the non-transfused patients, transfused patients had a higher incidence of any morbid event (9.1 vs. 2.5%. P < 0.0001), thrombotic events (4.6 vs. 1.1%, P = 0.0025), and hospital-acquired infections (2.3 vs. 0.6%, P = 0.039). Renal, respiratory, and ischemic morbidity occurred less frequently and were not more common in transfused patients. Risk-adjusted analysis revealed a dose-response effect, whereby for each unit of allogeneic blood transfused, the risks of any morbid event (OR 1.183; 95% CI 1.103-1.274; P < 0.0001), thrombotic complication (OR 1.104; 95% CI 1.032-1.194; P = 0.0035), and infectious complication (OR 1.182; 95% CI 1.077-1.332; P = 0.0002) were increased.

CONCLUSION

Our data demonstrate risk-adjusted and transfusion dose-related increases in perioperative morbidity, with thrombotic and infectious events being the most common.

Variation in Use of Blood Transfusion in Primary Total Hip and Knee Arthroplasties

BACKGROUND

There is growing clinical and policy emphasis on minimizing transfusion use in elective joint arthroplasty, but little is known about the degree to which transfusion rates vary across US hospitals. This study aimed to assess hospital-level variation in use of allogeneic blood transfusion in patients undergoing elective joint arthroplasty and to characterize the extent to which variability is attributable to differences in patient and hospital characteristics.

METHODS

The study population included 228,316 patients undergoing total knee arthroplasty (TKA) at 922 hospitals and 88,081 patients undergoing total hip arthroplasty (THA) at 606 hospitals from January 1, 2009 to December 31, 2011 in the Nationwide Inpatient Sample database, a 20% stratified sample of US community hospitals.

RESULTS

The median hospital transfusion rates were 11.0% (interquartile range, 3.5%-18.5%) in TKA and 15.9% (interquartile range, 5.4%-26.2%) in THA. After fully adjusting for patient- and hospital-related factors using mixed-effects logistic regression models, the average predicted probability of blood transfusion use in TKA was 6.3%, with 95% of the hospitals having a predicted probability between 0.37% and 55%. For THA, the average predicted probability of blood transfusion use was 9.5%, with 95% of the hospitals having a predicted probability between 0.57% and 66%. Hospital transfusion rates were inversely associated with hospital procedure volume and directly associated with length of stay.

CONCLUSION

The use of blood transfusion in elective joint arthroplasty varied widely across US hospitals, largely independent of patient case-mix and hospital characteristics.

Surgical apgar score in patients undergoing lumbar fusion for degenerative spine diseases

OBJECTIVE

Lumbar fusion is a procedure broadly performed for degenerative diseases of spines, but it is not without significant morbidities. Surgical Apgar Score (SAS), based on intraoperative blood loss, blood pressure, and heart rate, was developed for prognostic prediction in general and vascular operations. We aimed to examine whether the application of SAS in patients undergoing fusion procedures for degeneration of lumbar spines predicts in-hospital major complications.

METHODS

One hundred and ninety-nine patients that underwent lumbar fusion operation for spine degeneration were enrolled in this retrospective study. Based on whether major complications were present (N=16) or not (N=183), the patients were subdivided. We identified the intergroup differences in SAS and clinical parameters.

RESULTS

The incidence of in-hospital major complications was 8%. The duration of hospital stay for the morbid patents was significantly prolonged (p=0.04). In the analysis of multivariable logistic regression, SAS was an independent predicting factor of the complications after lumbar fusion for degenerative spine diseases [p=0.001; odds ratio (95% confidence interval)=0.35 (0.19-0.64)]. Lower scores were accompanied with higher rates of major complications, and the area was 0.872 under the receiver operating characteristic curve.

CONCLUSION

SAS is an independent predicting factor of major complications in patients after fusion surgery for degenerative diseases of lumbar spines, and provides good risk discrimination. Since the scoring system is relatively simple, objective, and practical, we suggest that SAS be included as an indicator in the guidance for level of care after lumbar fusion surgery.

Smoking is Associated with Increased Blood Loss and Transfusion Use After Lumbar Spinal Surgery

BACKGROUND

Little is known about the association between smoking and intraoperative blood loss and perioperative transfusion use in patients undergoing spinal surgery. However, we found that although many of the common complications and deleterious effects of smoking on surgical patients had been well documented, the aspect of blood loss seemingly had been overlooked despite data reported in nonorthopaedic sources to suggest a possible connection.

QUESTIONS/PURPOSES

We asked: (1) Is smoking associated with increased estimated blood loss during surgery in patients undergoing lumbar spine surgery? (2) Is smoking associated with increased perioperative transfusion usage?

METHODS

Between 2005 and 2009, 581 lumbar decompression procedures (with or without fusion) were performed at one academic spine center. Of those, 559 (96%) had sufficient chart documentation to categorize patients by smoking status, necessary intra- and postoperative data to allow analysis with respect to bleeding and transfusion-related endpoints, and who did not meet exclusion criteria. Exclusion criteria included: patients whose smoking status did not fit in our two categories, patients with underlying coagulopathy, patients receiving anticoagulants (including aspirin and platelet inhibitors), history of hepatic disease, history of platelet disorder or other blood dyscrasias, and patient or family history of any other known bleeding disorder. Smoking history in packs per day was obtained for all subjects. We defined someone as a smoker if the patient reported smoking up until the day of their surgical procedure; nonsmokers were patients who quit smoking at least 6 weeks before surgery or had no history of smoking. We used a binomial grouping for whether patients did or did not receive a transfusion perioperatively. Age, sex, number of levels of discectomies, number of levels decompressed, number of levels fused, and use of instrumentation were recorded. The same approaches were used for transfusions in all patients regardless of smoking history; decisions were made in consultation between the surgeon and the anesthesia team. Absolute indications for transfusion postoperatively were: a hemoglobin less than 7 g/dL, continued symptoms of dizziness, tachycardia, decreased exertional tolerance, or hypotension that failed to respond to fluid resuscitation. Multiple linear regression analyses correcting for the above variables were performed to determine associations with intraoperative blood loss, while logistic regression was used to analyze perioperative transfusion use.

RESULTS

After controlling for potentially relevant confounding variables noted earlier, we found smokers had increased estimated blood loss compared with nonsmokers (mean, 328 mL more for each pack per day smoked; 95% CI, 249-407 mL; p < 0.001). We also found that again correcting for confounders, smokers had increased perioperative transfusion use compared with nonsmokers (odds ratio, 13.8; 95% CI, 4.59-42.52).

CONCLUSIONS

Smoking is associated with increased estimated surgical blood loss and transfusion use in patients undergoing lumbar spine surgery. Patients who smoke should be counseled regarding these risks and on smoking cessation before undergoing lumbar surgery.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Effectiveness of preoperative autologous blood donation for protection against allogeneic blood exposure in adult spinal deformity surgeries: a propensity-matched cohort analysis

OBJECTIVE

The goal of this study was to examine the effectiveness of preoperative autologous blood donation (PABD) in adult spinal deformity (ASD) surgery.

METHODS

Patients undergoing single-stay ASD reconstructions were identified in a multicenter database. Patients were divided into groups according to PABD (either PABD or NoPABD). Propensity weighting was used to create matched cohorts of PABD and NoPABD patients. Allogeneic (ALLO) exposure, autologous (AUTO) wastage (unused AUTO), and complication rates were compared between groups.

RESULTS

Four hundred twenty-eight patients were identified as meeting eligibility criteria. Sixty patients were treated with PABD, of whom 50 were matched to 50 patients who were not treated with PABD (NoPABD). Nearly one-third of patients in the PABD group (18/60, 30%) did not receive any autologous transfusion and donated blood was wasted. In 6 of these cases (6/60, 10%), patients received ALLO blood transfusions without AUTO. In 9 cases (9/60, 15%), patients received ALLO and AUTO blood transfusions. Overall rates of transfusion of any type were similar between groups (PABD 70% [42/60], NoPABD 75% [275/368], p = 0.438). Major and minor in-hospital complications were similar between groups (Major PABD 10% [6/60], NoPABD 12% [43/368], p = 0.537; Minor PABD 30% [18/60], NoPABD 24% [87/368], p = 0.499). When controlling for potential confounders, PABD patients were more likely to receive some transfusion (OR 15.1, 95% CI 2.1-106.7). No relationship between PABD and ALLO blood exposure was observed, however, refuting the concept that PABD is protective against ALLO blood exposure. In the matched cohorts, PABD patients were more likely to sustain a major perioperative cardiac complication (PABD 8/50 [16%], NoPABD 1/50 [2%], p = 0.046). No differences in rates of infection or wound-healing complications were observed between cohorts.

CONCLUSIONS

Preoperative autologous blood donation was associated with a higher probability of perioperative transfusions of any type in patients with ASD. No protective effect of PABD against ALLO blood exposure was observed, and no risk of perioperative infectious complications was observed in patients exposed to ALLO blood only. The benefit of PABD in patients with ASD remains undefined.

Significant Blood Loss in Lumbar Fusion Surgery for Degenerative Spine

OBJECTIVE

Lumbar fusion is a widely used procedure for degenerative spine diseases but frequently is accompanied with substantial surgical blood loss. We aimed to investigate the risk factors for significant intraoperative blood loss and the influence of excessive bleeding on postoperative complications in patients undergoing fusion for degenerative lumbar spines.

METHODS

For this retrospective study, we enrolled 199 patients who had undergone lumbar fusion surgery for degeneration. The definition of significant blood loss at operation was 500 mL or more in blood volume. The patients were subdivided into 2 groups on the basis of whether significant blood loss was present (n = 107) or not (n = 92).

RESULTS

The incidence of significant blood loss during lumbar fusion was 53.8%. In the multivariate logistic regression model, the independent risk factors for significant blood loss included body mass index (P = 0.027), extreme spinal canal narrowing (P = 0.023), spine fusion segments >1 level (P = 0.008), and transforaminal lumbar interbody fusion (P = 0.006). Significant blood loss in lumbar fusion was associated with a greater incidence of postoperative complications (P = 0.002). The length of hospital stay for patents with excessive bleeding was prolonged significantly (P = 0.045).

CONCLUSIONS

Because substantial bleeding in lumbar fusion is associated with a greater incidence of morbidities and prolonged length of hospital stay, attention to the risk factors for significant blood loss is important in the preoperative assessment and postoperative guidance for the level of care.

Patient-, procedure-, and hospital-related risk factors of allogeneic and autologous blood transfusion in pediatric spinal fusion surgery in the United States

STUDY DESIGN

Cross-sectional study using data from the Health Care Cost and Utilization Project Kids' Inpatient Database.

OBJECTIVE

Blood loss during spinal fusion surgery may lead to the need for transfusion. Preoperative identification of patient-related, procedure-related, or hospital-related risk factors for blood transfusion would allow for implementation of interventions designed to control excessive bleeding.

SUMMARY OF BACKGROUND DATA

Several studies have analyzed predictors associated with transfusion in spinal fusion. Identified predictors include age, female sex, anemia, comorbidities, number of fusion levels, osteotomy, and greater hospital volume. There have been few studies examining these predictors in children undergoing spinal fusion.

METHODS

Using Kids' Inpatient Database data, univariate and multivariate logistic regression was used to calculate unadjusted and adjusted odds ratios (aOR). P values of less than 0.05 were considered statistically significant.

RESULTS

We identified 9538 pediatric hospitalizations (patients <21 yr) with spinal fusion in 2009. Overall, 25.1% were associated with blood transfusion. The following factors were associated with transfusions: female sex (aOR 1.14, P = 0.023), black race (aOR 1.35, P = 0.005), length of hospital stay (aOR 1.03, P < 0.001), anterior approach/lumbar segment (aOR 2.11, P = 0.011) and posterior approach/lumbar segment (aOR 2.75, P < 0.001) compared with anterior approach/cervical segment, midlength fusion (aOR 1.71, P < 0.001), and long length fusion (aOR 2.85, P < 0.001) compared with short length. Higher transfusion rates were observed in patients with complications of fever and hematoma but not wound infection.

CONCLUSION

This study showed significant patient-, procedure-, and hospital-related predictors of allogeneic and autologous blood transfusion in spinal fusion in the pediatric age group. Higher health care resource utilization of length of stay and additional procedures are directed toward care of this transfused subgroup. Therapies to reduce blood loss and transfusion requirement are necessary for this pediatric population.

LEVEL OF EVIDENCE

4.

Primary total knee arthroplasty allogenic transfusion trends, length of stay, and complications: nationwide inpatient sample 2000-2009

Perioperative blood loss leading to blood transfusion continues to be an issue for total knee arthroplasty (TKA) patients. The US Nationwide Inpatient Sample (NIS) was used to determine annual trends in allogenic blood transfusion rates, and effects of transfusion on in-hospital mortality, length of stay (LOS), costs, discharge disposition, and complications of primary TKA patients. TKA patients between 2000 and 2009 were included (n = 4,544,999) and categorized as: (1) those who received a transfusion of allogenic blood, and (2) those who did not. Transfusion rates increased from 7.7% to 12.2%. For both transfused and not transfused groups, mortality rates and mean LOS declined, while total costs increased. Transfused patients were associated with adjusted odds ratios of in-hospital mortality (AOR 1.16; P = 0.184), 0.71 ± 0.01 days longer LOS (P < 0.0001), and incurred ($1777 ± 36; P < 0.0001) higher total costs per admission.

Minorities are less likely to receive autologous blood transfusion for major elective orthopaedic surgery

BACKGROUND

Surgeons commonly arrange for patients to perform autologous blood donation before elective orthopaedic surgery. Understanding sociodemographic patterns of use of autologous blood transfusion can help improve quality of care and cost containment.

QUESTIONS/PURPOSES

We sought to determine whether there were (1) racial disparities, (2) insurance-based disparities, or (3) income-based disparities in autologous blood use. Additionally, we evaluated the combined effect of (4) race and insurance and (5) race and income on autologous blood use, and we compared ratios of autologous with allogeneic blood use.

METHODS

Of the more than 3,500,000 patients undergoing major elective orthopaedic surgery identified in the Nationwide Inpatient Sample between 2008 and 2011, 2.4% received autologous blood transfusion and 12% received allogeneic blood transfusion. Multivariable logistic regression was performed to determine the influence of race, insurance status, and income on autologous blood use.

RESULTS

Compared with white patients, Hispanic patients had lower odds of autologous blood use for elective hip (odds ratio [OR], 0.75; 95% CI, 0.69-0.82) and knee arthroplasties (OR, 0.71; 95% CI, 0.67-0.75). Black patients had lower odds of receiving autologous blood transfusion for hip arthroplasty (OR, 0.78; 95% CI, 0.74-0.83). Compared with the privately insured, uninsured and publicly insured patients were less likely to receive autologous blood for total joint arthroplasty and spinal fusion. Patients with low and medium income were less likely to have autologous blood transfusion for total joint arthroplasty and spinal fusion compared with high-level income earners. Even at comparable income and insurance levels with whites, Hispanic and black patients tended to be less likely to receive autologous blood transfusion. Ratios of autologous to allogeneic blood use were lower among minority patients.

CONCLUSIONS

Historically disadvantaged populations receive fewer autologous blood transfusions for elective orthopaedic surgery. Whether the differential use is attributable to patient preference or unequal access to this practice should be investigated further.

LEVEL OF EVIDENCE

Level II, prognostic study. See the Instructions for Authors for a complete description of levels of evidence.

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.

Predictors of allogeneic blood transfusion in spinal fusion in the United States, 2004-2009

STUDY DESIGN

Retrospective study.

OBJECTIVE

To examine the predictors of allogeneic blood transfusion (ALBT) in spinal fusion.

SUMMARY OF THE BACKGROUND DATA

Spinal fusion is among the most common surgical procedures that necessitate blood transfusion.

METHODS

Using the appropriate International Classification of Diseases, 9th revision, Clinical Modification (ICD-9-CM) codes, patients who underwent spinal fusion from 2004 to 2009 were identified in the Nationwide Inpatient Sample database. These patients were then divided into groups of those who received ALBT and those who did not, using the appropriate ICD-9-CM code. Patient demographics, surgical variables, and hospital characteristics were also retrieved. Multivariate logistic regression analysis was performed to identify the predictors of ALBT in spinal fusion.

RESULTS

Significant predictors of ALBT in spinal fusion included age, female sex, race status, weight loss, anemia, Elixhauser Comorbidity Score, autologous-related blood transfusion, surgical level, surgical approach, revision surgery, number of fused vertebrae, and insurance status. Pediatric and elderly patients were more likely to receive ALBT than middle-aged patients. African American and Hispanic patients were more likely to receive ALBT than Caucasian patients. As the Elixhauser Comorbidity Score increased, the odds ratio increased (score ≥4; odds ratio, 3.07). Thoracolumbar fusion was the strongest predictor among surgery-related variables (odds ratio, 8.56). Private insurance patients were less likely to receive ALBT than Medicare patients.

CONCLUSION

This study identified significant predictors of ALBT in spinal fusion. These factors need to be taken into consideration when developing a patient blood management strategy before surgery. In this study, autologous-related blood transfusion could not avoid ALBT; on the contrary, it was a significant predictor.

LEVEL OF EVIDENCE

3.

Transfusion rates are increasing following total hip arthroplasty: risk factors and outcomes

Despite attempts to minimize exposure to allogeneic blood, there are little data on recent nationwide trends in transfusion following total hip arthroplasty (THA) and no consensus on indications. The purpose of this study was to examine the rate, predictors, and inpatient outcomes associated with transfusion after primary THA. This retrospective cohort study analyzed the data collected from US Nationwide Inpatient Sample (NIS) for each year during the period 2005-2008 to assess the trends in transfusion in patients who underwent elective primary THA. Logistic regression models were used to evaluate the predictive risk factors for blood transfusion. The University Hospital Consortium (UHC) database was also queried to examine the variability in rates of transfusion at different academic medical centers. A total of 129,901 patients were identified in the NIS database. The transfusion rates following THA consistently increased from 18.12% in 2005 to 21.21% in 2008 (P<0.0001). Hospitals in the Northeast and Midwest region had the highest and lowest rates of transfusion, respectively. Significant risk factors for blood transfusion were female gender (odds ratio, OR 2.1), age above 85 (OR 2.9), African-American race (OR 1.7), Medicare payor status (OR 1.6), being at a hospital in the Northeast Region (OR 1.4), the presence of preoperative anemia (OR 1.6), having at least one comorbidity (OR 1.3), and a high Charlson Index score (OR 2.2). Patients receiving blood transfusions had increased in-hospital mortality, longer lengths of stay, and higher total charges compared to non-transfused patients (P<0.001). The UHC database demonstrated that transfusion rates vary widely across different institutions from <5% to >80%. The incidence of blood transfusion has recently increased following total hip arthroplasty and there is great variability in practice. We identified several patient risk factors along with the morbidity and mortality independently associated with transfusion following THA. Further work is needed to standardize the approach to blood conservation and minimize exposure to allogenic blood.

Blood transfusions in radical prostatectomy: a contemporary population-based analysis

OBJECTIVE

To examine the homologous blood transfusion (HBT), autologous blood transfusion (ABT) and intraoperative blood conservation technique (IOBCT) rates and trends at open (ORP) and minimally invasive radical prostatectomy (MIRP).

METHODS

The Nationwide Inpatient Sample was queried. Multivariable logistic regression models focused on all three transfusion types. Covariables consisted of procedure specific annual hospital caseload (AHC), year of surgery, age, Charlson Comorbidity Index, and region.

RESULTS

Overall, 119,966 patients underwent radical prostatectomy between 1998 and 2007. The HBT, ABT, and IOBCT rates were 6.2%, 6.0%, and 1.2%, respectively. HBT rates ranged from 5.1-5.1% between 1998 and 2007 (P=.49) vs 9.4-2.7% (P<.001) for ABT vs 1.9-0.9% (P=.003) for IOBCT in the same time period, respectively. In multivariable analyses, ORP patients treated at intermediate (odds ratio [OR] 1.48, P=.003) and low (OR 2.73, P<.001) AHC institutions were more likely to receive an HBT than ORP patients treated at high AHC institutions. Conversely, MIRP patients treated at high (OR 0.46, P=.040), intermediate (OR 0.27, P=.001), and low (OR 0.59, P=.015) AHC institutions were less likely to receive an HBT than ORP patients treated at high AHC institutions.

CONCLUSION

Our results indicate that the overall transfusion rate at radical prostatectomy decreased within the last decade because of a substantial decline in ABT use. Moreover, MIRP protects from HBT, even when performed at low AHC Centers.

Transfusion strategy for primary knee and hip arthroplasty: impact of an algorithm to lower transfusion rates and hospital costs

BACKGROUND

Blood transfusion strategies should reduce both blood transfusion and costs. Possible solutions include autologous donation for selected patients and the prescription of erythropoietin (EPO).

METHODS

We conducted a quality improvement program to examine the effect of a transfusion strategy algorithm in primary knee (TKA) and hip arthroplasty (THA). Our algorithm is presented as a diagram and is based on tolerated and expected blood losses. Patient characteristics, blood loss, transfusions given, autologous blood wastage, and costs were examined during an initial evaluation and after implementation of the algorithm.

RESULTS

Analysis of 302 (initial evaluation) and 173 (post-implementation) arthroplasties demonstrated a 55% reduction in the prescription of autologous blood donation. The proportion of EPO prescriptions increased from 6.6% to 17.3% (P<0.05). There was a 56% overall reduction in transfusions to fewer autologous (32% vs 12%, P<0.0001) and allogeneic transfusions (21% vs 13%, NS). There were 50% fewer wasted autologous blood units (P=0.002) and a 50% reduction in hospital costs (euro345 vs 169) with no significant change in overall costs (euro439 vs 407). Anaesthetists applied the algorithm in 97% of patients, and it is still in use 1 yr after evaluation.

CONCLUSIONS

In this study, the implementation of an algorithm for transfusion strategy changed practice and improved quality of care. The costs for EPO, its administration, and monitoring outside hospital were offset by the reduction in hospital transfusion costs.

Accuracy of identification of patients with immune thrombocytopenic purpura through administrative records: a data validation study

Administrative data are commonly used to estimate the prevalence of a disease, but the validity of the coding system needs to be evaluated before its use. We assessed the validity of the International Classification of Disease, 9(th) version, Clinical Modification (ICD-9-CM) code of 287.3 for identifying patients with immune thrombocytopenic purpura (ITP). Administrative data from inpatients and outpatients seen were retrieved if the patient or insurer was billed with one of three ICD-9-CM codes for thrombocytopenic disorders, 287.3, 287.4, and 287.5, as a primary or secondary diagnosis; or was physician-identified as having ITP. The electronic medical records for these patients were systematically reviewed to identify patients with ITP and with non-ITP diagnoses. Sensitivity, specificity, positive and negative predictive values, and kappa scores were calculated separately for inpatients and outpatients. Four-hundred eighteen records were reviewed. Among inpatients, the sensitivity of code 287.3 for indicating a diagnosis of ITP was 100% [95% confidence interval 94-100%]. The specificity was 89% [95% confidence interval 84-94%]. The percent agreement was 92%, and the kappa statistic was 0.80. For outpatients, the sensitivity of the billing code 287.3 was 84% [95% confidence interval 76-91%], a conservative estimate because of how the patients with other diagnoses were selected. The specificity for outpatients was 66% [95% confidence interval 56-76%]. ICD-9-CM code 287.3 in administrative billing data is likely to be sufficiently sensitive and specific, particularly when inpatient data are used, for the estimation of the prevalence of ITP.