Preoperative anemia does not predict complications after single-level lumbar fusion: a propensity score-matched multicenter study

Postoperative Outcomes for Spinal Fusion Procedures in Pediatric Patients with Anemia: A Retrospective and Multivariate Analysis

BACKGROUND

Preoperative anemia is known to be associated with perioperative complications in many surgical interventions. Here, we examine the effects of preoperative anemia on peri-operative complications and postoperative outcomes in pediatric patients undergoing spinal fusion.

METHODS

Retrospective analysis was conducted using the American College of Surgeons Pediatric National Surgery Quality Improvement Program Database between 2012-2020. Current Procedural Terminology codes 22800, 22,802, 22,804, 22,840, 22,842, 22,843, and 22,844 were included to represent all primary spinal fusion procedures performed. Patients without preoperative hematocrit (HCT) levels were excluded. Classification of anemia was determined via age- and sex-adjusted HCT levels. Patient demographics, preoperative comorbidities and risk factors, and 30-day postoperative outcomes were compared between the 2 cohorts using univariate analysis. Multivariate logistic regressions were performed to determine if anemia severity was independently associated with worse postoperative outcomes.

RESULTS

A total of 30,243 pediatric patients were included in this study, with 26,621 not having preoperative anemia and 3622 having preoperative anemia. Pediatric patients with anemia have increased length of stay (LOS) (6.7 ± 9.6 vs. 5 ± 6, P < 0.001), 30-day unplanned reoperation rate (4% vs. 2.8%, P < 0.001), and total blood transfused (489.9 ± 497.8 vs. 423.4 ± 452.6, P < 0.001). Multivariate analysis supported anemia and degree of its severity as an independent predictor of increased length of stay (LOS), reoperation rate, and postoperative complications.

CONCLUSIONS

Preoperative anemia leads to worse outcomes in pediatric spinal fusion procedures. Utilizing HCT recordings could be factored into the equation for optimal patient selection and prevention of post-operative complications.

The effect of preoperative anemia on perioperative outcomes among patients undergoing emergency surgery: A multicenter prospective cohort study

Introduction

Preoperative anemia is a common finding among surgical patients. It is associated with an increased risk of perioperative morbidity and mortality. Outcomes among emergency surgical patients are not established. This study aimed to assess the effect of preoperative anemia on perioperative outcomes among patients undergoing emergency surgery in selected Southern Ethiopia governmental teaching hospitals, Southern Ethiopia, 2022.

Method

A multicenter prospective cohort study was conducted. Data were collected at selected hospitals, after obtaining ethical approval from the institutional review board. Descriptive statistics, cross-tabulation, and multivariable binary logistic regression analysis were performed. A P-value less than 0.05 were taken as statistically significant.

Result

A total of 200 patients who underwent emergency surgery were grouped into the anemia group (100 patients) while the rest were in the non-anemia group. There was no statistically significant difference between the groups regarding socio-demographic and intraoperative patient characteristics. Based on multivariate logistic regression, anemia group had a significant risk of perioperative transfusion requirement (Relative Risk (RR) = 4.030, p < 0.001), developing postoperative complications (RR = 1.868, p = 0.017), occurring in-hospital mortality (RR = 5.763, p = 0.045), prolong the length of hospital stay (RR = 4.028, p < 0.001), and requiring postoperative intensive care unit admission (RR = 6.332, p = 0.003) compared with non-anemia groups.

Conclusion

Preoperative anemia was associated with a higher rate of perioperative transfusion requirements, along with increased postoperative complication, increased in-hospital mortality, increased Intensive Critical Care Unit admission rate, and prolonged length of hospital stay. We recommend adequate preoperative assessment and correction of hemoglobin concentrations to normal values to improve surgical outcomes and reduce complications.

Analysis of risk factors for perioperative complications in spine surgery

Complications in spine surgery can arise in the intraoperative or the immediate postoperative period or in a delayed manner. These complications may lead to severe or even permanent morbidity if left undiagnosed and untreated. We prospectively interviewed 526 patients out of 1140 patients who consecutively underwent spinal surgery in our department between November 2017 and November 2018 and analysed the outcome and complication rates. A 12 months follow-up period was also adopted. We analysed the patients' clinical characteristics, comorbidities, surgical management, survival rates, and outcomes. Risk factor analyses for the development of complications were also performed. Patients' median age was 67 years (range: 13-96). The main diagnoses were as follows: degenerative in 50%, tumour in 22%, traumatic fractures in 13%, infections in 10%, reoperations in 3%, and others in 2%. Surgeries were emergency procedures (within 24 h) in 12%. Furthermore, 59% required instrumentation. The overall postoperative complication rate was 26%. Revision surgery was required in 12% of cases within 30 postoperative days (median time to revision 11 days [IQR 5-15 days]). The most frequent complications included wound healing disorders, re-bleeding, and CSF leakage. Thereby, the risk factor analysis revealed age-adjusted CCI (p = 0.01), metastatic tumour (p = 0.01), and atrial fibrillation (p = 0.02) as significant risk factors for postoperative complications. Additionally, postoperative KPS (p = 0.004), postoperative anaemia (p = 0.001), the length of hospital stay (p = 0.02), and duration of surgery (p = 00.002) were also identified as associated factors. Complication rates after spinal surgeries are still high, especially in patients with metastatic tumour disease and poor clinical status (KPS), requiring revision surgeries in several cases. Therefore, specific risk factors should be determined to carefully select surgery groups.

Risks associated with perioperative anaemia and perioperative blood transfusion in patients undergoing neurosurgical operation

OBJECTIVE

To investigate the prevalence of preoperative anaemia and the risks associated with perioperative anaemia and blood transfusion in patients who underwent neurological surgery.

BACKGROUND

Perioperative anaemia has an important impact on neurosurgery patients. The prevalence and risks of perioperative anaemia and blood transfusion in Chinese patients are still unknown.

METHODS

Logistic regression was used to predict adverse outcomes of red blood cell (RBC) transfusion and different levels of anaemia. Anaemia and transfusion were compared as independent variables by using a 1:1 match on propensity score.

RESULTS

The prevalence of preoperative anaemia in neurosurgical patients was 20.05%; 10.33% patients received RBC transfusion. Perioperative RBC and plasma transfusion rates (P < .001) and average hospital costs (P = .0365) were higher in preoperative moderate-to-severe anaemia patients than in no anaemia patients. Perioperative RBC transfusion patients had longer hospital length of stay (LOS) (P < .001) and higher average hospital costs (P < .001) than no-transfusion patients. The rates of return to the operating room (OR) within 30 days and intensive care unit stay did not demonstrate any significant difference in anaemia and transfusion cohorts, respectively.

CONCLUSION

The status of preoperative anaemia in Chinese neurosurgical patients is associated with increased transfusion rates and hospital costs. Perioperative RBC transfusion is associated with increased length and cost of hospitalisation.

Anemia and perioperative mortality in non-cardiac surgery patients: a secondary analysis based on a single-center retrospective study

Background

Evidence regarding the relationship between anemia and perioperative prognosis is controversial. The study was conducted to highlight the specific relationship between anemia and perioperative mortality in non-cardiac surgery patients over 18 years of age.

Methods

This study was a retrospective analysis of the electronic medical records of 90,784 patients at the Singapore General Hospital from January 1, 2012 to October 31, 2016. Multivariate regression, propensity score analysis, doubly robust estimation, and an inverse probability-weighting model was used to ensure the robustness of our findings.

Results

We identified 85,989 patients, of whom75, 163 had none or mild anemia (Hemoglobin>90g/L) and 10,826 had moderate or severe anemia (Hemoglobin≤90g/L). 8,857 patients in each study exposure group had similar propensity scores and were included in the analyses. In the doubly robust model, postoperative 30-day mortality rate was increased by 0.51% (n = 219) in moderate or severe anemia group (Odds Ratio, 1.510; 95% Confidence Interval (CI), 1.049 to 2.174) compared with none or mild anemia group (2.47% vs.1.22%, P<0.001). Moderate or severe anemia was also associated with increased postoperative blood transfusion rates (OR, 5.608; 95% CI, 4.026 to 7.811, P < 0.001). There was no statistical difference in Intensive Care Unit (ICU) admission rate among different anemia groups within 30 days after surgery (P=0.104).

Discussion

In patients undergoing non-cardiac surgery over 18 years old, moderate or severe preoperative anemia would increase the occurrence of postoperative blood transfusion and the risk of death, rather than ICU admission within 30 days after surgery.

The Role of Potentially Modifiable Factors in a Standard Work Protocol to Decrease Complications in Adult Spinal Deformity Surgery: A Systematic Review, Part 1

STUDY DESIGN

Structured Literature Review.

OBJECTIVES

We sought to evaluate the peer-reviewed literature for potentially modifiable patient and surgical factors that could be incorporated into a Standard Work protocol to decrease complications in adult spinal deformity (ASD) surgery.

SUMMARY OF BACKGROUND DATA

Lean Methodology uses Standard Work to improve efficiency and decrease waste and error. ASD is known to have a high surgical complication rate. Several patient and surgical potentially modifiable factors have been suggested to affect complications, including preoperative hemoglobin, bone density, body mass index (BMI), age-appropriate realignment, preoperative albumin/prealbumin, and smoking status. We sought to evaluate the literature for evidence supporting these factors to include in a Standard Work protocol to decrease complications.

METHODS

Each of these six factors was developed into an appropriate clinical question that included the patient population, surgical intervention, a comparison group, and outcomes measure (PICO question). A comprehensive literature search was then performed. The authors reviewed abstracts and analyzed data from included studies. From 456 initial citations with abstract, 173 articles underwent full-text review. The best available evidence for clinical questions regarding the influence of these factors was provided by 93 included studies.

RESULTS

We found fair evidence supporting a low preoperative hemoglobin level associated with increased transfusion rates and decreased BMD and increased BMI associated with increased complication rates. Fair evidence supported low albumin/prealbumin associated with increased complications. There was fair evidence associating smoking exposure to increased reoperations, but conflicting evidence associating it with increased complications. There was no evidence in the literature evaluating age-appropriate realignment and complications.

CONCLUSION

Preoperative hemoglobin, bone density, body mass index, preoperative albumin/prealbumin, and smoking status all are potentially modifiable risk factors that are associated with increased complications in the adult spine surgery population. Developing a Standard Work Protocol for patient evaluation and optimization should include these factors.

LEVEL OF EVIDENCE

Level II.

Patient Blood Management: Recommendations From the 2018 Frankfurt Consensus Conference

IMPORTANCE

Blood transfusion is one of the most frequently used therapies worldwide and is associated with benefits, risks, and costs.

OBJECTIVE

To develop a set of evidence-based recommendations for patient blood management (PBM) and for research.

EVIDENCE REVIEW

The scientific committee developed 17 Population/Intervention/Comparison/Outcome (PICO) questions for red blood cell (RBC) transfusion in adult patients in 3 areas: preoperative anemia (3 questions), RBC transfusion thresholds (11 questions), and implementation of PBM programs (3 questions). These questions guided the literature search in 4 biomedical databases (MEDLINE, EMBASE, Cochrane Library, Transfusion Evidence Library), searched from inception to January 2018. Meta-analyses were conducted with the GRADE (Grading of Recommendations, Assessment, Development, and Evaluation) methodology and the Evidence-to-Decision framework by 3 panels including clinical and scientific experts, nurses, patient representatives, and methodologists, to develop clinical recommendations during a consensus conference in Frankfurt/Main, Germany, in April 2018.

FINDINGS

From 17 607 literature citations associated with the 17 PICO questions, 145 studies, including 63 randomized clinical trials with 23 143 patients and 82 observational studies with more than 4 million patients, were analyzed. For preoperative anemia, 4 clinical and 3 research recommendations were developed, including the strong recommendation to detect and manage anemia sufficiently early before major elective surgery. For RBC transfusion thresholds, 4 clinical and 6 research recommendations were developed, including 2 strong clinical recommendations for critically ill but clinically stable intensive care patients with or without septic shock (recommended threshold for RBC transfusion, hemoglobin concentration <7 g/dL) as well as for patients undergoing cardiac surgery (recommended threshold for RBC transfusion, hemoglobin concentration <7.5 g/dL). For implementation of PBM programs, 2 clinical and 3 research recommendations were developed, including recommendations to implement comprehensive PBM programs and to use electronic decision support systems (both conditional recommendations) to improve appropriate RBC utilization.

CONCLUSIONS AND RELEVANCE

The 2018 PBM International Consensus Conference defined the current status of the PBM evidence base for practice and research purposes and established 10 clinical recommendations and 12 research recommendations for preoperative anemia, RBC transfusion thresholds for adults, and implementation of PBM programs. The relative paucity of strong evidence to answer many of the PICO questions supports the need for additional research and an international consensus for accepted definitions and hemoglobin thresholds, as well as clinically meaningful end points for multicenter trials.

Risk Factors for Adverse Cardiac Events After Lumbar Spine Fusion

Background

To determine the incidence and risk factors for adverse cardiac events after lumbar spine fusion.

Methods

A total of 50 495 patients were identified through the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database who underwent lumbar spine fusion between 2005 and 2015. The 30-day postoperative data were analyzed to assess for the incidence of adverse cardiac events including cardiac arrest or myocardial infarction. Of those who experienced an event, patient- and surgery-specific parameters were evaluated to assess for risk factors.

Results

A total of 240 cardiac events occurred in the studied cohort (4.76 events/1000 patients). Factors that were associated with an increased cardiac risk were age (odds ratio [OR] = 1.039, 95% confidence interval [CI] = 1.03, 1.05, P < .001), male sex (OR = 1.51, 95% CI = 1.17, 1.94, P = .001), insulin-dependent diabetes (OR = 1.83, 95% CI = 1.29, 2.6, P = .001), American Society of Anesthesiologists (ASA) score >3 (OR = 1.92, 95% CI = 1.00, 3.65, P = .048), absolute hematocrit different from 45 (OR = 1.07, 95% CI = 1.04, 1.10, P < .001), and smoking (OR = 1.39, 95% CI = 1.02, 1.90, P = .04). The impact of sustaining a cardiac event in the setting of single-level lumbar fusion is catastrophic as the 30-day postoperative mortality rate for those sustaining an event was 24.6% (59/240 patients), compared to 0.2% (87/50 255) for those not sustaining an event (P < .001).

Conclusions

Cardiac events after lumbar fusion are a rare but devastating series of complications. Several risk factors were identified, including insulin-dependent diabetes mellitus, smoking, advanced age, male sex, ASA score of >3, and anemia/polycythemia. Considering the severity of these consequences, appropriate risk stratification is imperative, and optimization of modifiable risk factors may mitigate this risk.

Comparing Short-term Complications of Inpatient Versus Outpatient Single-level Anterior Cervical Discectomy and Fusion: An Analysis of 6940 Patients Using the ACS-NSQIP Database

STUDY DESIGN

Multicenter propensity score-adjusted retrospective cohort study.

OBJECTIVE

To determine baseline 30-day complication rates for anterior cervical discectomy and fusion (ACDF) and compare clinical complications for patients undergoing single-level ACDFs between inpatient and outpatient settings.

SUMMARY OF BACKGROUND DATA

ACDF remains the most common procedure in the treatment of a variety of cervical disc pathologies, making it a focus of quality improvement initiatives. Outpatient single-level ACDFs are becoming more common and offer advantages including reducing nosocomial infections and costs, as well as improved patient satisfaction.

MATERIALS AND METHODS

The 2011-2013 NSQIP datasets were queried to identify all patients who underwent single-level ACDF procedures using current procedural terminology codes. Outpatient and inpatient cohorts were matched 1:1 using propensity score analysis to assess short-term outcomes. The outcomes assessed included 30-day medical and surgical complications, reoperation, readmission, and mortality.

RESULTS

In total, 6940 patients underwent a single-level ACDF with an overall complication rate of 4.2%. A total of 5162 patients (74.4%) had an inpatient hospital stay after surgery, whereas 1778 patients (25.6%) had outpatient surgery. After matching based on preoperative and operative characteristics to account for potential confounders, the overall complication rate was higher in the inpatient arm compared with the outpatient arm (2.5% vs. 1.2%; P=0.003). The 30-day readmission rate was also higher but not significant in the inpatient group than the outpatient group (2.2% vs. 1.8%; P=0.355). Mortality was the same with 0.1% in both groups (P=0.564).

CONCLUSIONS

Patients undergoing outpatient single-level ACDF had a lower 30-day complication rates than those undergoing it in the inpatient setting. Outpatient surgery for single-level ACDF is safe and a favorable option for suitable patients.

LEVEL OF EVIDENCE

Level 3.

Impact of Anemia and Transfusion on Readmission and Length of Stay After Spinal Surgery: A Single-center Study of 1187 Operations

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To determine whether receipt of blood transfusion and preoperative anemia are associated with increased rates of 30-day all-cause readmission, and secondarily with a prolonged hospital stay after spinal surgery.

SUMMARY OF BACKGROUND DATA

Increased focus on health care quality has led to efforts to determine postsurgical readmission rates and predictors of length of postoperative hospital stay. Although there are still no defined outcome measures specific to spinal surgery to which providers are held accountable, efforts to identify appropriate measures and to determine modifiable risk factors to optimize quality are ongoing.

METHODS

Records from 1187 consecutive spinal surgeries at Northwestern Memorial Hospital in 2010 were retrospectively reviewed and data were collected that described the patient, surgical procedure, hospital course, complications, and readmissions. Presence or absence of transfusion during the surgery and associated hospital course was treated as a binary variable. Multivariate negative binomial regression and logistic regression were used to model length of stay and readmission, respectively.

RESULTS

Nearly one fifth (17.8%) of surgeries received transfusions, and the overall readmission rate was 6.1%. After controlling for potential confounders, we found that the presence of a transfusion was associated with a 60% longer hospital stay [adjusted incidence rate ratio=1.60 (1.34-1.91), P<0.001], but was not significantly associated with an increased rate of readmission [adjusted odds ratio=0.81 (0.39-1.70), P=0.582]. Any degree of preoperative anemia was associated with increased length of stay, but only severe anemia was associated with an increased rate of readmission.

CONCLUSIONS

Both receipt of blood transfusion and any degree of preoperative anemia were associated with increased length of hospital stay after controlling for other variables. Severe anemia, but not receipt of blood transfusion, was associated with increased rate of readmission. Our findings may help define actions to reduce length of stay and decrease rates of readmission.

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.

Results of Database Studies in Spine Surgery Can Be Influenced by Missing Data

BACKGROUND

National databases are increasingly being used for research in spine surgery; however, one limitation of such databases that has received sparse mention is the frequency of missing data. Studies using these databases often do not emphasize the percentage of missing data for each variable used and do not specify how patients with missing data are incorporated into analyses. This study uses the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database to examine whether different treatments of missing data can influence the results of spine studies.

QUESTIONS/PURPOSES

(1) What is the frequency of missing data fields for demographics, medical comorbidities, preoperative laboratory values, operating room times, and length of stay recorded in ACS-NSQIP? (2) Using three common approaches to handling missing data, how frequently do those approaches agree in terms of finding particular variables to be associated with adverse events? (3) Do different approaches to handling missing data influence the outcomes and effect sizes of an analysis testing for an association with these variables with occurrence of adverse events?

METHODS

Patients who underwent spine surgery between 2005 and 2013 were identified from the ACS-NSQIP database. A total of 88,471 patients undergoing spine surgery were identified. The most common procedures were anterior cervical discectomy and fusion, lumbar decompression, and lumbar fusion. Demographics, comorbidities, and perioperative laboratory values were tabulated for each patient, and the percent of missing data was noted for each variable. These variables were tested for an association with "any adverse event" using three separate multivariate regressions that used the most common treatments for missing data. In the first regression, patients with any missing data were excluded. In the second regression, missing data were treated as a negative or "reference" value; for continuous variables, the mean of each variable's reference range was computed and imputed. In the third regression, any variables with > 10% rate of missing data were removed from the regression; among variables with ≤ 10% missing data, individual cases with missing values were excluded. The results of these regressions were compared to determine how the different treatments of missing data could affect the results of spine studies using the ACS-NSQIP database.

RESULTS

Of the 88,471 patients, as many as 4441 (5%) had missing elements among demographic data, 69,184 (72%) among comorbidities, 70,892 (80%) among preoperative laboratory values, and 56,551 (64%) among operating room times. Considering the three different treatments of missing data, we found different risk factors for adverse events. Of 44 risk factors found to be associated with adverse events in any analysis, only 15 (34%) of these risk factors were common among the three regressions. The second treatment of missing data (assuming "normal" value) found the most risk factors (40) to be associated with any adverse event, whereas the first treatment (deleting patients with missing data) found the fewest associations at 20. Among the risk factors associated with any adverse event, the 10 with the greatest effect size (odds ratio) by each regression were ranked. Of the 15 variables in the top 10 for any regression, six of these were common among all three lists.

CONCLUSIONS

Differing treatments of missing data can influence the results of spine studies using the ACS-NSQIP. The current study highlights the importance of considering how such missing data are handled.

CLINICAL RELEVANCE

Until there are better guidelines on the best approaches to handle missing data, investigators should report how missing data were handled to increase the quality and transparency of orthopaedic database research. Readers of large database studies should note whether handling of missing data was addressed and consider potential bias with high rates or unspecified or weak methods for handling missing data.

Preoperative and Postoperative Factors and Laboratory Values Predicting Outcome in Patients Undergoing Lumbar Fusion Surgery

OBJECTIVE

To determine whether complications in lumbar fusion surgery could be estimated from patient factors and perioperative laboratory values. In addition, risk scores for detection of patients prone to complications were defined.

METHODS

We retrospectively collected data of patients undergoing lumbar fusion surgery between 2013 and 2015. The patients were divided into group A (no complications) and group B (systemic and infectious complications within 30 days postoperatively). Patient-related factors and levels of perioperative laboratory values were compared between the groups and analyzed for possible impact on complications and length of stay (LOS) in the hospital.

RESULTS

Data of 132 consecutive patients (74 women [56.1%]; median age, 68.5 years) were analyzed. Postoperative complications occurred in 29.5%. Higher postoperative creatine kinase (CK) and C-reactive protein and lower postoperative hemoglobin and thrombocyte values, as well as higher differences between preoperative and postoperative CK, C-reactive protein, and hemoglobin values were associated with postoperative complications. Among others, the combinations of advanced age and elevated body mass index (P = 0.0062, odds ratio: 3.018), or advanced age, elevated body mass index, and postoperative CK >166 U/L (P = 0.0016, odds ratio: 3.637) revealed patients with a threefold risk for complications. The combination of advanced age, American Society of Anesthesiologists score >2, and preoperative hemoglobin <12.9 g/dL was associated with a LOS of 20.3 versus 11 days (P = 0.01).

CONCLUSIONS

Patients with postoperative complications and extended LOS seem to show significant differences in various perioperative laboratory values and patient factors. Perioperative risk assessments using cut-off values and risk scores may help identify patients prone to complications and extended resource use.

The effect of anaemia on hospital length of stay in lumbar decompression and fusion procedures

Ways of reducing the length of hospital stay have received increased attention in recent years. Both preoperative and postoperative anaemia have been implicated as causative agents in increasing postoperative length of stay (LOS). In a retrospective study, 317 patients that underwent lumbar decompression and fusion surgery were assessed. Two separate block multivariate linear regression analyses were performed to evaluate the impact of preoperative anaemia, postoperative anaemia, and the degree of perioperative haemoglobin drop on LOS. Other anaemia related factors were also assessed. Preoperative anaemia, postoperative anaemia, and the amount of perioperative haemoglobin drop were all shown to prolong the length of hospitalisation and therefore to increase overall healthcare costs. Following strict anaemia corrective maneuvers could reasonably be expected to reduce expenditure.