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

Development of personalized machine learning-based prediction models for short-term postoperative outcomes in patients undergoing cervical laminoplasty

PURPOSE

By predicting short-term postoperative outcomes before surgery, patients undergoing cervical laminoplasty (CLP) surgery could benefit from more accurate patient care strategies that could reduce the likelihood of adverse outcomes. With this study, we developed a series of machine learning (ML) models for predicting short-term postoperative outcomes and integrated them into an open-source online application.

METHODS

National surgical quality improvement program database was utilized to identify individuals who have undergone CLP surgery. The investigated outcomes were prolonged length of stay (LOS), non-home discharges, 30-day readmissions, unplanned reoperations, and major complications. ML models were developed and implemented on a website to predict these three outcomes.

RESULTS

A total of 1740 patients that underwent CLP were included in the analysis. Performance evaluation indicated that the top-performing models for each outcome were the models built with TabPFN and LightGBM algorithms. The TabPFN models yielded AUROCs of 0.830, 0.847, and 0.858 in predicting non-home discharges, unplanned reoperations, and major complications, respectively. The LightGBM models yielded AUROCs of 0.812 and 0.817 in predicting prolonged LOS, and 30-day readmissions, respectively.

CONCLUSION

The potential of ML approaches to predict postoperative outcomes following spine surgery is significant. As the volume of data in spine surgery continues to increase, the development of predictive models as clinically relevant decision-making tools could significantly improve risk assessment and prognosis. Here, we present an accessible predictive model for predicting short-term postoperative outcomes following CLP intended to achieve the stated objectives.

Interpretable machine learning models to predict short-term postoperative outcomes following posterior cervical fusion

By predicting short-term postoperative outcomes before surgery, patients who undergo posterior cervical fusion (PCF) surgery may benefit from more precise patient care plans that reduce the likelihood of unfavorable outcomes. We developed machine learning models for predicting short-term postoperative outcomes and incorporate these models into an open-source web application in this study. The American College of Surgeons National Surgical Quality Improvement Program database was used to identify patients who underwent PCF surgery. Prolonged length of stay, non-home discharges, and readmissions were the three outcomes that were investigated. To predict these three outcomes, machine learning models were developed and incorporated into an open access web application. A total of 6277 patients that underwent PCF surgery were included in the analysis. The most accurately predicted outcome in terms of the area under the receiver operating characteristic curve (AUROC) was the non-home discharges with a mean AUROC of 0.812, and the most accurately predicting algorithm in terms of AUROC was the LightGBM algorithm with a mean AUROC of 0.766. The following URL will take users to the open access web application created to provide predictions for individual patients based on their characteristics: https://huggingface.co/spaces/MSHS-Neurosurgery-Research/NSQIP-PCF. Machine learning techniques have a significant potential for predicting postoperative outcomes following PCF surgery. The development of predictive models as clinically useful decision-making tools may significantly improve risk assessment and prognosis as the amount of data in spinal surgery keeps growing. Here, we present predictive models for PCF surgery that are meant to accomplish the aforementioned goals and make them publicly available.

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.

Practical Considerations of Perioperative Assessment and Optimization in Major Colorectal Surgery

Successful outcomes after colorectal surgery result not only from technique in the operating room, but also from optimization of the patient prior to surgery. This article will discuss the role of preoperative assessment and optimization in the colorectal surgery patient. Through discussion of the various clinical models, readers will understand the range of options available for optimization. This study will also present information on how to design a preoperative clinic and the barriers to success.

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.

Nationwide Readmission Rates and Hospital Charges for Patients With Surgical Evacuation of Nontraumatic Subdural Hematomas: Part 1-Craniotomy

BACKGROUND

Despite patients experiencing high recurrence and readmission rates after surgical management of nontraumatic subdural hematomas (SDHs), few studies have examined the causes and predictors of unplanned readmissions in this population on a national scale.

OBJECTIVE

To analyze independent factors predicting 30-day hospital readmissions after surgical treatment of nontraumatic SDH in patients who survived their index surgery and evaluate hospital readmission rates and charges.

METHODS

Using the Nationwide Readmissions Database, we identified patients who underwent craniotomy for nontraumatic SDH evacuation (2010-2015) using a retrospective cohort observational study design. National estimates and variances within the cohort were calculated after stratifying, hospital clustering, and weighting variables.

RESULTS

Among 49 013 patients, 10 643 (21.7%) had at least 1 readmission within 30 days of their index treatment and 38 370 (78.3%) were not readmitted. Annual readmission rates did not change during the study period ( P = .74). The most common primary causes of 30-day readmissions were recurrent SDH (n = 3949, 37.1%), venous thromboembolism (n = 1373, 12.9%), and delayed hyponatremia and syndrome of inappropriate antidiuretic hormone secretion (n = 1363, 12.8%). Comorbidities that independently predicted readmission included congestive heart failure, chronic obstructive pulmonary disease, coagulopathy, diabetes mellitus, liver disease, lymphoma, fluid and electrolyte disorders, metastatic cancer, peripheral vascular disease, psychosis, and renal failure ( P ≤ .03). Household income in the 51st to 75th percentile was associated with a decreased risk of readmission.

CONCLUSION

National trends in 30-day readmission rates after nontraumatic SDH treatment by craniotomy provide quality benchmarks that can be used to drive quality improvement efforts on a national level.

Perioperative management in complex spine surgery: a narrative review

The last two decades have seen a significant increase in the number of spine surgical procedures performed worldwide. This type of surgery includes a wide variety of procedures, from mini-invasive discectomies to multi-level spinal arthrodesis and osteotomies. Moreover, different surgical approaches are described at different spine levels: the anesthesiologist should be aware of the potential benefits and risks for the patients and be prepared for their management. In this narrative review we seek to describe basic concepts of perioperative spine care and address evolving areas in which care is changing. We will discuss preoperative concerns, intraoperative management including airway management, choice of maintenance, intraoperative neuromonitoring and anesthetic effect, blood management and the dynamic topic of anesthetic and analgesic techniques. Finally, we will briefly address the issue of perioperative complications as they relate specifically to spine surgery.

Spine Surgery and Preoperative Hemoglobin, Hematocrit, and Hemoglobin A1c: A Systematic Review

STUDY DESIGN

Systematic review.

OBJECTIVES

Synthesize previous studies evaluating clinical utility of preoperative Hb/Hct and HbA1c in patients undergoing common spinal procedures: anterior cervical discectomy and fusion (ACDF), posterior cervical fusion (PCF), posterior lumbar fusion (PLF), and lumbar decompression (LD).

METHODS

We queried PubMed, Embase, Cochrane Library, and Web of Science for literature on preoperative Hb/Hct and HbA1c and post-operative outcomes in adult patients undergoing ACDF, PCF, PLF, or LD surgeries.

RESULTS

Total of 4,307 publications were assessed. Twenty-one articles met inclusion criteria.

PCF AND ACDF

Decreased preoperative Hb/Hct were significant predictors of increased postoperative morbidity, including return to operating room, pulmonary complications, transfusions, and increased length of stay (LOS). For increased HbA1c, there was significant increase in risk of postoperative infection and cost of hospital stay.

PLF

Decreased Hb/Hct was reported to be associated with increased risk of postoperative cardiac events, blood transfusion, and increased LOS. Elevated HbA1c was associated with increased risk of infection as well as higher visual analogue scores (VAS) and Oswestry disability index (ODI) scores.

LD

LOS and total episode of care cost were increased in patients with preoperative HbA1c elevation.

CONCLUSION

In adult patients undergoing spine surgery, preoperative Hb/Hct are clinically useful predictors for postoperative complications, transfusion rates, and LOS, and HbA1c is predictive for postoperative infection and functional outcomes. Using Hct values <35-38% and HbA1c >6.5%-6.9% for identifying patients at higher risk of postoperative complications is most supported by the literature. We recommend obtaining these labs as part of routine pre-operative risk stratification.

LEVEL OF EVIDENCE

III.

30-Day Outcomes for Total Ankle Arthroplasty in Patients With Anemia

BACKGROUND

While anemia has been associated with poor surgical outcomes in total knee arthroplasty and total hip arthroplasty, the effects of anemia on total ankle arthroplasty remain unknown. This study examines how preoperative anemia affects postoperative outcomes in total ankle arthroplasty.

METHODS

A retrospective analysis was performed using the American College of Surgeons National Surgery Quality Improvement Project database from 2011 to 2018 for total ankle arthroplasty procedures. Hematocrit (HCT) levels were used to determine preoperative anemia.

RESULTS

Of the 1028 patients included in this study, 114 patients were found to be anemic. Univariate analysis demonstrated anemia was significantly associated with an increased average hospital length of stay (2.2 vs 1.8 days, P < .008), increased rate of 30-day readmission (3.5% vs 1.1%, P = .036), increased 30-day reoperation (2.6% vs 0.4%, P = .007), extended length of stay (64% vs 49.9%, P = .004), wound complication (1.75% vs 0.11%, P = .002), and surgical site infection (2.6% vs 0.6%, P = .017). Multivariate logistic regression analysis found anemia to be significantly associated with extended hospital length of stay (odds ratio [OR], 1.62; 95% CI, 1.07-2.45; P = .023) and increased reoperation rates (OR, 5.47; 95% CI, 1.15-26.00; P = .033). Anemia was not found to be a predictor of increased readmission rates (OR, 3.13; 95% CI, 0.93-10.56; P = .066) or postoperative complications (OR, 1.27; 95% CI, 0.35-4.56; P = .71).

CONCLUSION

This study found increasing severity of anemia to be associated with extended hospital length of stay and increased reoperation rates. Providers and patients should be aware of the increased risks of total ankle arthroplasty with preoperative anemia.

LEVEL OF EVIDENCE

Level III, retrospective comparative study.

The Effect of Discharging Patients with Low Hemoglobin Levels on Hospital Readmission and Quality of Life after Adult Spinal Deformity Surgery

Study Design

Retrospective cohort.

Purpose

This study aims to evaluate the impact of anemia on functional outcomes, health-related quality of life (HRQoL), and early hospital readmission (EHR) rates after adult spinal deformity (ASD) surgery at the time of discharge from the hospital.

Overview of Literature

Concerns with risks of transfusion, insufficient evidence for its benefits, and the possibility of associated adverse outcomes have led to restrictive transfusion practices. Therefore, patients are discharged according to patient blood management programs that are implemented in hospitals nationwide to reduce unnecessary blood transfusions. However, not many comprehensive kinds of studies exist on the effect of postoperative anemia on functional life and complications.

Methods

Anemia severity was defined following the 2011 World Health Organization guidelines. All patients had HRQoL tests as well as complete blood counts pre- and postoperatively. EHR is the admission within 30 days of discharge and was used as the dependent parameter.

Results

This study comprised 225 surgically treated ASD patients with a median age of 62.0 years, predominantly women (80%). Of the 225 patients, 82, 137, and six had mild, moderate, and severe anemia at the time of discharge, respectively. Seventeen of the patients (mild [11, 64.7%]; moderate [5, 29.4%]; severe [1, 5.9%]) were readmitted within 30 days. The mean hemoglobin values were higher in readmitted patients (p=0.071). Infection was the leading cause of readmission (n=12), but a low hemoglobin level was not observed in any of these patients at the time of discharge. Except for Scoliosis Research Society-22 questionnaire, HRQoL improvements did not reach statistical significance in early readmitted patients in the first year after surgery.

Conclusions

The results of this study demonstrated that the occurrence and the severity of postoperative anemia are not associated with EHR in surgically treated patients with ASD. The findings of the current research suggested that clinical awareness of the parameters other than postoperative anemia may be crucial. Thus, improvements in HRQoL scores were poor in early readmitted patients 1 year after surgery.

Risk Factors for 30-Day Non-Neurological Morbidity and Cerebrospinal Fluid Leak in Patients Undergoing Surgery for Vestibular Schwannoma

Introduction  We analyzed perioperative risk factors for morbidity and mortality for the patients undergoing surgical intervention for vestibular schwannoma along with rates of cerebrospinal fluid (CSF) leaks that required surgery. Materials and Methods  Patients undergoing surgery vestibular schwannoma were identified in the American College of Surgeons National Surgical Quality Improvement Program database from 2012 to 2016 using current procedural terminology (CPT) codes for posterior fossa surgical approaches and International Classification of Diseases 9th revision (ICD 9) and ICD 10 codes for peripheral nerve sheath tumor. Preoperative laboratories, comorbidities, and operative times were analyzed along with CSF leaks and unplanned returns to the operating room. Results  Nine-hundred ninety-three patients fit the inclusion criteria. Average age was 51, 41% were male, and 58% were female. Mortality within 30 days of the operation was very low at 0.4%, complications were 7% with infection being the most common at 2.3%, and unplanned reoperations happened in 7.4% of the cases. Dependent functional status (odds ratio [OR]: 5.7, 95% confidence interval [CI]: 1.9-16.6, p  = 0.001), preoperative anemia (OR: 2.4, 95% CI: 1.2-4.5, p  = 0.009), and operative time over 8 hours (OR: 1.9, 95% CI: 1.1-3.4, p  = 0.017) were the only significant predictors of perioperative complications. CSF leak postoperatively occurred in 37 patients (3.7%). Reoperation for CSF leak was necessary in 56.3% of the cases. Operative time over 8 hours was the only independent significant predictor of postoperative CSF leak (OR: 2.2, 95% CI: 1.1-4.3, p  = 0.028). Conclusion  Dependent functional status preoperatively, preoperative anemia, and duration of surgery over 8 hours are the greatest predictors of complications in the 30-day postoperative period.

Hematocrit as a predictor of preoperative transfusion-associated complications in spine surgery: A NSQIP study

BACKGROUND CONTEXT

Preoperative optimization of medical comorbidities prior to spinal surgery is becoming an increasingly important intervention in decreasing postoperative complications and ensuring a satisfactory postoperative course. The treatment of preoperative anemia is based on guidelines made by the American College of Cardiology (ACC), which recommends packed red blood cell transfusion when hematocrit is less than 21% in patients without cardiovascular disease and 24% in patients with cardiovascular disease. The literature has yet to quantify the risk profile associated with preoperative pRBC transfusion.

PURPOSE

To determine the incidence of complications following preoperative pRBC transfusion in a cohort of patients undergoing spine surgery.

STUDY DESIGN

Retrospective review of a national surgical database.

PATIENT SAMPLE

The national surgical quality improvement program database OUTCOME NEASURES: Postoperative physiologic complications after a preoperative transfusion. Complications were defined as the occurrence of any DVT, PE, stroke, cardiac arrest, myocardial infarction, longer length of stay, need for mechanical ventilation greater than 48 h, surgical site infections, sepsis, urinary tract infections, pneumonia, or higher 30-day mortality.

METHODS

The national surgical quality improvement program database was queried, and patients were included if they had any type of spine surgery and had a preoperative transfusion.

RESULTS

Preoperative pRBC transfusion was found to be protective against complications when the hematocrit was less than 20% and associated with more complications when the hematocrit was higher than 20%. In patients with a hematocrit higher than 20%, pRBC transfusion was associated with longer lengths of stay, and higher rates of ventilator dependency greater than 48 h, pneumonia, and 30-day mortality.

CONCLUSION

This is the first study to identify an inflection point in determining when a preoperative pRBC transfusion may be protective or may contribute to complications. Further studies are needed to be conducted to stratify by the prevalence of cardiovascular disease.

Degenerative Cervical Myelopathy: Review of Surgical Outcome Predictors and Need for Multimodal Approach

Degenerative cervical myelopathy is the most common cause of spinal cord injury in the elderly population in the developed world, and it significantly affects the quality of life of patients and their caregivers. Surgery remains the only treatment option able to halt disease progression and provide neurological recovery for most patients. Although it has remained challenging to predict exactly who will experience improvement after surgery, increasingly it has been shown that clinical, imaging, and electrophysiological factors can predict, with relatively good capacity, those more likely to benefit. Clinically, the baseline neurological impairment appears to be strongly related to the outcome, and the magnetic resonance imaging findings of T1-weighted hypointensity and the length of T2-weighted hyperintensity appear to be the most prognostic. In this context, electrophysiology findings (both motor and sensory evoked potentials) have shown some predictive capacity. However, large studies are lacking. Although multivariate models have been conducted using clinical and magnetic resonance imaging data, no multimodal prediction models are available that encompass the predictive capacity of clinical, imaging, and electrophysiological data. In the present review, we examined the rationale for clinical, imaging, and electrophysiological usage in clinical practice and discussed a model of multimodal assessment for the management of degenerative cervical myelopathy.

The Relationship Between Gastrointestinal Comorbidities, Clinical Presentation and Surgical Outcome in Patients with DCM: Analysis of a Global Cohort

Degenerative cervical myelopathy (DCM) is the most common cause of spinal cord impairment in adults, presenting most frequently in patients 50 years or older. Gastrointestinal comorbidities (GICs) commonly occur in this group; however, their relationship with DCM has not been thoroughly investigated. It is the objective of the present study to investigate the difference between patients with or without GICs who are surgically treated for DCM. A cohort of 757 patients with clinical data and 458 with magnetic resonance imaging (MRI) data from the AOSpine North America and AOSpine International studies on DCM was evaluated. GICs were obtained at presentation and included gastric, intestinal, hepatic, and pancreatic conditions. Patients were dichotomized into 2 groups: those with GICs and those without GICs. Both clinical and MRI presentation, as well as baseline neurological and functional status, were compared. Neurological and functional outcomes at 2-year follow-up were also compared. GICs were present in 121 patients (16%). These patients were less commonly male (48.76% vs. 65.4%, p = 0.001) and were slightly less neurologically impaired based on the Nurick grade (3.05 ± 1.10 vs. 3.28 ± 1.16, p = 0.044) but not based on mJOA (12.74 ± 2.62 vs. 12.48 ± 2.76, p = 0.33). They also had a worse physical health score (32.80 ± 8.79 vs. 34.65 ± 9.38 p = 0.049), worse neck disability (46.31 ± 20.04 vs. 38.23 ± 20.44, p < 0.001), a lower prevalence of upper motor neuron signs (hyperreflexia, 70.2% vs. 78.9%, p = 0.037; Babinski’s sign 24.8% vs. 37.3%, p = 0.008), and a higher rate of psychiatric comorbidities (31.4% vs. 10.4%, p < 0.0001). On MRI, GIC patients less commonly exhibited signal intensity changes (T2 hyperintensity, 49.2% vs. 75.6%, p < 0.001; T1 hypointensity, 9.7% vs. 21.1%, p = 0.036), and had a lower number of T2 hyperintensity levels (0.82 ± 0.98 vs. 1.3 ± 1.11, p = 0.001). There was no difference in surgical outcome between the groups. DCM patients with GICs are more likely to be female and have significantly more general health impairment and neck disability. However, these patients have less clinical and MRI features typical of more severe neurological impairment. This constellation of symptoms is considerably different than those typically observed in DCM, and it is therefore plausible that nutritional factors may contribute to this unique observation.

Association of Preoperative Anemia With 30-Day Morbidity and Mortality Among Patients With Thyroid Cancer Who Undergo Thyroidectomy

Importance

Despite the ease of preoperative anemia diagnosis and the availability of treatment options, the morbidity and mortality associated with this condition remain unacceptably high, and the literature describing the association of preoperative anemia with postoperative outcomes following thyroid surgery in patients with thyroid cancer remain sparse. Reporting outcomes in this patient population may help to facilitate preoperative optimization.

Objective

To assess whether an association exists between preoperative anemia and outcomes following thyroid surgery in patients with thyroid cancer.

Design, Setting, and Participants

This retrospective, cross-sectional, cohort study used the American College of Surgeons National Surgical Quality Improvement Program database to identify 32 166 patients between 2007 and 2016 with Current Procedural Terminology codes for thyroid surgery and with the International Classification of Diseases, Ninth Revision code of malignant thyroid cancer.

Exposures

Preoperative anemia as defined using the World Health Organization criteria of hematocrit less than 36% in nonpregnant females and less than 39% in males.

Main Outcomes and Measures

Multivariable logistic regression analysis was conducted to assess the association of preoperative anemia with the following 30-day postoperative outcomes: pulmonary, infectious, and cardiac complications, overall and serious morbidity (surgical site infection and medical complications), prolonged hospital length of stay (≥75th percentile for the cohort), and mortality.

Results

Among the 24 912 patients with thyroid cancer who underwent thyroidectomy included in the final analysis, the median (interquartile range) age was 51 (40-62) years and the majority were women (18 705 [75.1%]). The prevalence of preoperative anemia was 12.5% (n = 3108). Within the overall study population, hypertension (9242 patients [37.1%]) followed by active smoking (2992 patients [12.0%]) were the most prevalent comorbidities. The unadjusted odds of anemia vs no anemia were significantly higher for every 10-year increase in age (odds ratio [OR], 1.10; 95% CI, 1.08-1.13) and for black vs white patients (OR, 2.82; 95% CI, 2.51-3.17). The adjusted odds of postoperative overall morbidity (OR, 1.68; 95% CI, 1.29-2.17), mortality (OR, 3.36; 95% CI, 1.37-8.28), and pulmonary (OR, 2.36; 95% CI, 1.65-3.34) and infectious (OR, 1.62; 95% CI, 1.12-2.29) complications were higher in patients with preoperative anemia than in those without preoperative anemia.

Conclusions and Relevance

The findings from this study suggest that preoperative anemia may not only be associated with racial differences and a higher comorbidity burden but may also increase the likelihood of postoperative morbidity and mortality. These results may provide a basis for further risk reduction strategies and preoperative optimization.

Prevalence of anemia and its relationship with neurological status in patients undergoing surgery for degenerative cervical myelopathy and radiculopathy: A retrospective study of 2 spine centers

Both degenerative cervical myelopathy (DCM) and anemia are common among older patients, however insufficient data exists evaluating their co-occurrence and the influence of anemia on baseline neurological status. To address this, we examined a retrospective multicenter series of patients treated for DCM or radiculopathy. Myelopathy was graded using the Nurick scale. Established criteria for diagnosing abnormalities were used to identify blood abnormalities, including macrocytic and microcytic anemia. Multivariable regression was used to determine the impact of hematological anomalies on Nurick grades. In our analysis, we included 725 patients (age of 57.1 ± 11.7), of whom 398 presented with myelopathy and 327 presented with radiculopathy alone. Twenty six percent of all patients were anemic at baseline and the mean preoperative Nurick grade across all patients was 2.09 ± 1.29; mean Nurick grade amongst those with DCM was 2.98 ± 1.12. Compared to those with myelopathy, patients with radiculopathy were significantly younger (53.8 ± 11.0 vs 59.8 ± 11.6, p < 0.001) and less likely to be anemic (16.8% vs 33.7%, p < 0.0001). Nurick grading was significantly higher in myelopathy patients with anemia (3.13 ± 1.19 vs 2.91 ± 1.07, p = 0.05) and macrocytic anemia (4.00 ± 1.41 vs 2.97 ± 1.11, p = 0.04). Multivariate regression demonstrated that anemia (p < 0.001), age (p < 0.0001), and posterior surgical approach (p < 0.0001) were related to worse preoperative Nurick grade. In sum, these data suggest that anemia and degenerative cervical spine pathologies commonly co-occur. Anemia, and macrocytic anemia specifically, is associated with poorer neurological status in myelopathic patients. These data suggest anemia may influence baseline neurological status and impact surgical recovery in patients treated for DCM or radiculopathy.

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.

Optimizing Preoperative Anemia to Improve Patient Outcomes

Anemia is a decrease in red blood cell mass, which hinders oxygen delivery to tissues. Preoperative anemia has been shown to be associated with mortality and morbidity following major surgery. The preoperative care clinic is an ideal place to start screening for anemia and discussing potential interventions in order to optimize patients for surgery. This article (1) reviews the relevant literature and highlights consequences of preoperative anemia in the surgical setting, and (2) suggests strategies for screening and optimizing anemia in the preoperative setting.