Hidden blood loss and its influencing factors after percutaneous kyphoplasty surgery: A retrospective study

Assessment of Hidden Blood Loss in Spinal Metastasis Surgery: A Comprehensive Approach with MRI-Based Radiomics Models

BACKGROUND

Patients undergoing surgery for spinal metastasis are predisposed to hidden blood loss (HBL), which is associated with poor surgical outcomes but unpredictable.

PURPOSE

To evaluate the role of MRI-based radiomics models for assess the risk of HBL in patients undergoing spinal metastasis surgery.

STUDY TYPE

Retrospective.

SUBJECTS

202 patients (42.6% female) operated on for spinal metastasis with a mean age of 58 ± 11 years were divided into a training (n = 162) and a validation cohort (n = 40).

FIELD STRENGTH/SEQUENCE

1.5T or 3.0T scanners. Sagittal T1-weighted and fat-suppressed T2-weighted imaging sequences.

ASSESSMENT

HBL was calculated using the Gross formula. Patients were classified as low and high HBL group, with 1000 mL as the threshold. Radiomics models were constructed with radiomics features. The radiomics score (Radscore) was obtained from the optimal radiomics model. Clinical variables were accessed using univariate and multivariate logistic regression analyses. Independent risk variables were used to build a clinical model. Clinical variables combined with Radscore were used to establish a combined model.

STATISTICAL TESTS

Predictive performance was evaluated using area under the curve (AUC), accuracy, sensitivity, specificity, and F1 score. Calibration curves and decision curves analyses were produced to evaluate the accuracy and clinical utility.

RESULTS

Among the radiomics models, the fusion (T1WI + FS-T2WI) model demonstrated the highest predictive efficacy (AUC: 0.744, 95% confidence interval [CI]: 0.576-0.914). The Radscore model (AUC: 0.809, 95% CI: 0.664-0.954) performs slightly better than the clinical model (AUC: 0.721, 95% CI: 0.524-0.918; P = 0.418) and the combined model (AUC: 0.752, 95% CI: 0.593-0.911; P = 0.178).

DATA CONCLUSION

A radiomics model may serve as a promising assessment tool for the risk of HBL in patients undergoing spinal metastasis surgery, and guide perioperative planning to improve surgical outcomes.

LEVEL OF EVIDENCE

3 TECHNICAL EFFICACY: Stage 2.

Hidden blood loss and its influencing factors after cement augmentation for vertebral metastasis

Introduction

Few studies have focused on the risk factors for hidden blood loss (HBL) during cement augmentation surgery for pathologic vertebral compression fraction (PVCFs).

Method

From January 2014 to December 2020, the clinical data of 169 PVCF patients (283 levels) who underwent cement augmentation were retrospectively analysed. HBL was calculated according to the linear Gross formula using the patient's average Hct during the perioperative course and PBV. Multivariate linear regression analysis was performed to evaluate the independent factors associated with HBL.

Results

The mean HBL was 448.2 ± 267.2 ml, corresponding to 10.8% ± 6.2% of the patient blood volume (PBV). There were significant differences between pre- and postoperative haematocrit (Hct) (P < 0.001) and Hb (P < 0.001), and 132 patients developed anaemia postoperatively, while 79 patients had anaemia preoperatively (P < 0.001). Multivariate linear regression revealed that bone lesion quality (p = 0.028), number of PVCFs (p = 0.002), amount of bone cement (p = 0.027), bone cement leakage (p = 0.001), and percentage of vertebral height loss (VHL) (p = 0.011) were independent risk factors for HBL.

Conclusion

In conclusion, patients with lytic vertebral destruction, larger amounts of bone cement, greater amounts of bone cement leakage, more PVCF(s), and greater percentages of VHL may be more prone to HBL.

Hidden blood loss in minimally invasive surgery for osteoporotic vertebral fractures

INTRODUCTION AND AIM

Minimally invasive surgery (MIS) of the spine prevents the collapse of osteoporotic vertebral fractures (OVF) with lower complication and bleeding rates than open surgery. However, the possibility of hidden blood loss (HBL) has been recently described, referring to the loss of blood diffused into tissues and lost through hemolysis. This study aimed to estimate the postoperative impact of HBL in patients undergoing MIS for OVF.

MATERIALS AND METHODS

This was a retrospective study of a series of patients who had MIS for OVF. A descriptive analysis of recorded variables was performed, and total blood volume, total bleeding, HBL, and hemoglobine drop were calculated. This was followed by a comparative analysis between HBL (<500ml vs. ≥500ml) and the variables of hospital stay and postoperative evolution. Binary logistic regression models were performed to rule out confounding factors.

RESULTS

A total of 40 patients were included, 8 men and 32 women, with a mean age of 76.6 years. The mean HBL was 682.5ml. An HBL greater than 500ml is found to be an independent risk factor for torpid postoperative evolution (P=0.035), while it does not predict a longer hospital stay (P=0.116). In addition, a higher HBL was observed in surgeries of greater technical complexity and longer surgical time.

CONCLUSIONS

Although MIS techniques have shown less intraoperative bleeding than open surgery, HBL should be diagnosed because it is associated with a torpid evolution. The use of a diagnostic and therapeutic algorithm may help minimize its impact.

Risk Factors Analysis and Nomogram Model Establishment of Hidden Blood Loss in Overweight and Obese Elderly Patients After Total Hip Arthroplasty

Background

Total hip arthroplasty (THA) has become the first-choice treatment for elderly patients with end-stage hip disease. The high amount of hidden blood loss (HBL) in overweight and obese patients after THA not only affects rapid recovery, but also results in a greater economic burden. We aimed to identify risk factors that contribute to elevated HBL in overweight and obese patients after THA by retrospective analysis, and establish a nomogram prediction model for massive HBL in overweight and obese patients after THA.

Methods

A total of 505 overweight and obese patients treated with THA were included and randomly divided into modeling and validation sets according to a 7:3 ratio. The demographic and relevant clinical data of the patients were collected. The independent risk factors affecting HBL after THA in overweight and obese patients were obtained by Pearson, independent sample T-test, and multiple linear regression analyses. R software was used to establish a nomogram prediction model for postoperative HBL, as well as a receiver operating characteristic (ROC) curve, calibration curve, and decision curve analysis (DCA).

Results

HBL was 911±438 mL, accounting for 79.5±13.1% of the total perioperative blood loss (1104±468 mL). A multiple linear regression analysis showed that HBL was associated with necrosis of the femoral head, absence of hypertension, longer operative time, higher preoperative erythrocytes, and higher preoperative D-dimer levels. The areas under the ROC curve (AUC) for the modeling and validation sets were 0.751 and 0.736, respectively, while the slope of the calibration curve was close to 1. The DCA curve demonstrated a better net benefit at a risk of HBL ≥1000 ml in both the training and validation groups.

Conclusion

HBL was an important component of total blood loss (TBL) after THA in overweight and obese patients. Necrosis of the femoral head, absence of hypertension, longer operative time, higher preoperative erythrocytes, and higher preoperative D-dimer levels were independent risk factors for postoperative HBL in these patients. The predictive model constructed based these data had better discriminatory power and accuracy, and could result in better net benefit for patients.

Bone Mineral Density T-Score is an Independent Predictor of Major Blood Loss in Adult Spinal Deformity Surgery

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVE

The purpose of this study was to determine the effect of low bone mineral density (BMD), as assessed by preoperative Dual-energy X-ray Absorptiometry (DEXA) scans, on intraoperative blood loss following adult spinal deformity (ASD) surgery.

METHODS

Patients who received spinal fusion for ASD (>5 levels fused) at a single academic center from 2010-2018 were included in this study. The lowest preoperative T-score was recorded for patients who had preoperative DEXA scans within a year of surgery. Patients with liver/kidney disease or on prescription anticoagulant medication were excluded. Major blood loss was a binary variable defined as above or below the 90th percentile of our cohort. Binomial regression was performed controlling for age, number of vertebrae fused, 3-column osteotomy, primary vs. revision surgery, preoperative platelet count, and if the patient was taking medication for osteoporosis.

RESULTS

91 patients were identified in the cohort. Mean age was 63 ± 11.6 years, 81% female. 56 (62%) of cases included revision of previous instrumentation. Patients had a mean SVA of 9.6 ± 8.6 cm and median of 9 vertebrae fused (range 5-22). The average T-score was -1.2 ± 1.0. Each point lower T-score was associated with significantly higher odds of major blood loss (OR 2.5, 95% CI 1.0 - 5.9) when controlling for age, number of vertebrae fused, 3-column osteotomy, preoperative platelet count and primary vs. revision surgery.

CONCLUSIONS

Preoperative T-score is independently associated with increased odds of major blood loss in ASD surgery.

Hidden blood loss in minimally invasive surgery for osteoporotic vertebral fractures

INTRODUCTION AND AIM

Minimally invasive surgery (MIS) of the spine prevents the collapse of osteoporotic vertebral fractures (OVF) with lower complication and bleeding rates than open surgery. However, the possibility of hidden blood loss (HBL) has been recently described, referring to the loss of blood diffused into tissues and lost through hemolysis. This study aimed to estimate the postoperative impact of HBL in patients undergoing MIS for OVF.

MATERIALS AND METHODS

This was a retrospective study of a series of patients who had MIS for OVF. A descriptive analysis of recorded variables was performed, and total blood volume (TBV), total bleeding (TB), HBL, and Hb drop were calculated. This was followed by a comparative analysis between HBL (<500mL vs. ≥500mL) and the variables of hospital stay and postoperative evolution. Binary logistic regression models were performed to rule out confounding factors.

RESULTS

A total of 40 patients were included, 8 men and 32 women, with a mean age of 76.6 years. The mean HBL was 682.5mL. An HBL greater than 500mL is found to be an independent risk factor for torpid postoperative evolution (p=0.035), while it does not predict a longer hospital stay (p=0.116). In addition, a higher HBL was observed in surgeries of greater technical complexity and longer surgical time.

CONCLUSIONS

Although MIS techniques have shown less intraoperative bleeding than open surgery, HBL should be diagnosed because it is associated with a torpid evolution. The use of a diagnostic and therapeutic algorithm may help minimize its impact.

Hidden blood loss and its influencing factors after minimally invasive percutaneous transpedicular screw fixation in thoracolumbar fracture

Background

Minimally invasive percutaneous transpedicular screw fixation (MIPTSF) is generally accepted as a minimally invasive treatment for thoracolumbar fracture. However, hidden blood loss (HBL) caused by this procedure is usually disregarded. This study aimed to investigate the amount of HBL and its influencing factors after MIPTSF in thoracolumbar fracture.

Methods

Between October 2017 and December 2020, a total of 146 patients (106 males and 40 females, age range 21–59 years) were retrospectively examined, and their clinical and radiological data were recorded and analyzed. The Pearson or Spearman correlation analysis was used to investigate an association between patient’s characteristics and HBL. Multivariate linear regression analysis was performed to elucidate the related clinical or radiological factors of HBL.

Results

A substantial amount of HBL (164.00 ± 112.02 ml, 40.65% of total blood loss (TBL)) occurred after transpedicular screw internal fixation. Multivariate linear regression analysis revealed that HBL was positively associated with TBL (p < .001), percentage of vertebral height loss (VHL) (p < .001), percentage of vertebral height restoration (VHR) (p < .001), numbers of fractured vertebrae (P = .013), and numbers of fixed vertebral segments (P = .002).

Conclusion

A large amount of HBL was incurred in patients undergoing MIPTSF in thoracolumbar fracture. More importantly, TBL, percentage of VHL, percentage of VHR, the numbers of fractured vertebrae and fixed vertebral segments were independent risk factors for HBL.

Quantification and influencing factors of perioperative hidden blood loss in patients undergoing laparoscopic ovarian cystectomy for benign ovarian tumours

This retrospective, monocentric study quantified hidden blood loss (HBL) and investigated its influencing factors in benign ovarian tumour patients undergoing laparoscopic ovarian cystectomy. Data from 153 patients who underwent laparoscopic ovarian cystectomy were retrospectively reviewed. HBL was calculated using the formula derived from 'Nadler' and 'Cross'. Pearson correlation was carried out to measure the association between HBL and potential risk factors. The average HBL was 280.22 ± 168.42 mL, accounting for 84.13 ± 19.20% of total blood loss (TBL) (347.48 ± 179.05 mL), which was a change of almost fourteen-fold relative to median visible blood loss [20.00 mL (10.00 mL, 57.5 mL)]. Surgical time, number of excisional tumours and preoperative albumin values were risk factors for HBL. HBL represents a large proportion more than 80% of TBL in patients undergoing laparoscopic ovarian cystectomy. Collectively, HBL is helpful for estimating intraoperative blood loss and better guidance of haemostatic agents, which reduces postoperative complications and expedites postoperative recovery. Additionally, the estimation of HBL also contributes to the summary, reflection and improvement of surgical technique.IMPACT STATEMENTWhat is already known on this subject? There has been a growing number of surgical patients with perioperative anaemia, which appears to be inconsistent with measured levels of visible intraoperative blood loss and postoperative drainage. This substantial but easily underestimated blood loss is known as hidden blood loss. To date, no published articles have evaluated HBL and its related risk factors in benign ovarian tumour patients undergoing laparoscopic ovarian cystectomy.What the results of this study add? HBL accounts for a large amount of TBL in laparoscopy for benign ovarian tumours. Surgical time, number of excisional tumours and preoperative albumin values are risk factors for HBL.What the implications are of these findings for clinical practice and/or further research? The management of HBL is important for the administration of perioperative blooding loss. In this context, HBL can be applied to estimate intraoperative blood loss and be better guidance of haemostatic agents to reduce postoperative complications and hasten postoperative rehabilitation. Additionally, the estimation of HBL also contributes to the summary, reflection and improvement of surgical technique.

Development and validation of a nomogram to predict complications in patients undergoing simultaneous bilateral total knee arthroplasty: A retrospective study from two centers

Purpose

Complications were significantly increased 30 days after Simultaneous bilateral total knee arthroplasty (SBTKA). In this study, an individualized nomogram was established and validated to predict the complications within 30 days after SBTKA.

Methods

The general data of 861 patients (training set) who received SBTKA in The Affiliated Hospital of Qingdao University between January 1, 2012 and March 31, 2017 were retrospectively analyzed. All patients were divided into complication group (n = 96) and non-complication group (n = 765) according to the incidence of complications within 30 years after SBTKA. Independent risk factors for postoperative SBTKA complications were identified and screened by binary logistic regression analyses, and then a nomogram prediction model was constructed using R software. The area under curve (AUC), calibration curve, and decision curve analysis (DCA) were selected to evaluate the line-chart. Meanwhile, 396 patients receiving SBTKA in the Third Hospital of Hebei Medical University who met the inclusion and exclusion criteria (test set) were selected to verify the nomogram.

Results

Five independent predictors were identified by binary logistic regression analyses and a nomogram was established. The AUC of this nomogram curve is 0.851 (95% CI: 0.819–0.883) and 0.818 (95% CI: 0.735–0.900) in the training and testing sets, respectively. In the training set and test set, calibration curves show that nomogram prediction results are in good agreement with actual observation results, and DCA shows that nomogram prediction results have good clinical application value.

Conclusion

Older age, lower preoperative hemoglobin level, higher preoperative blood urea nitrogen (BUN) level, longer operation time, ASA grade ≥ III are independent predictors of SBTKA complications within 30 days after surgery. A nomogram containing these five predictors can accurately predict the risk of complications within 30 days after SBTKA.

Perioperative Hidden Blood Loss in Lumbar Disk Herniation Patients With Percutaneous Endoscopic Transforaminal Discectomy and Influencing Factors

STUDY DESIGN

This was a retrospective study.

OBJECTIVES

This study aimed to evaluate hidden blood loss (HBL) and its influencing factors in lumbar disk herniation (LDH) patients treated with percutaneous endoscopic transforaminal discectomy (PETD).

SUMMARY OF BACKGROUND DATA

PETD is a minimally invasive spine surgery and is widely used to treat LDH. It is generally believed that there is less bleeding during PETD. However, HBL during the perioperative period is always ignored.

MATERIALS AND METHODS

From January 2018 to March 2021, 74 LDH patients treated with PETD was selected. The patient's sex, age, height, weight, previous medical history (hypertension and diabetes) and other basic information were recorded. The preoperative fibrinogen (FIB) level, activated partial thromboplastin time and prothrombin time were recoded. The hemoglobin, hematocrit, and platelet immediately after admission and the next day postoperative were recorded. The surgical time, intraoperative blood loss, intervertebral disk degeneration grade and soft tissue thickness of the PETD approach were recorded. The total blood loss was calculated according to the Gross formula, and then HBL was calculated based on total blood loss and visible blood loss (VBL). The influencing factors were analyzed by single factor correlation analysis and multivariate linear regression analysis.

RESULTS

Among the 74 patients, there were 34 males (20-68 y old) and 40 females (26-75 y old). The mean amount of VBL was (85.04±26.53) mL and HBL was (341.04±191.15) mL. There were statistically significant differences between HBL and VBL (P=0.000). Multiple linear regression analysis showed that sex (P=0.000), disk degeneration grade (P=0.000), preoperative FIB level (P=0.022) and preoperative platelet (P=0.026) were independent risk factors that contributed to HBL, but age (P=0.870), BMI (P=0.480), hypertension (P=0.867), diabetes (P=0.284), soft tissue thickness (P=0.701), preoperative prothrombin time (P=0.248) and preoperative activated partial thromboplastin time (P=0.521) were not.

CONCLUSIONS

There was a large amount of HBL during the perioperative period of PETD in patients with LDH. Sex, disk degeneration grade, preoperative FIB level and preoperative platelet are the independent risk factors of HBL in the perioperative period of PETD. More attention should be paid to the patients with risk factors to ensure perioperative safety.

Hidden blood loss in extreme lateral interbody fusion for adult spinal deformity

BACKGROUND

Extreme lateral interbody fusion (XLIF) is often used with posterior spinal fixation (PSF) to treat adult spinal deformity (ASD). However, the amount of intraoperative blood loss (IBL) reported for XLIF may underestimate the total blood loss (TBL). The objective of this study was to determine the total perioperative blood loss in XLIF for ASD.

METHODS

We assessed 30 consecutive ASD patients with Schwab-SRS type L (mean age: 68.7 ± 8.2 years; mean follow-up 2.0 ± 1.3 years) who were treated by multilevel XLIF (mean, 2.5 ± 0.6 levels) followed by PSF after 3-5 days. We calculated the TBL after XLIF by the Gross equation, by hemoglobin (Hb) balance, and by the Orthopedic Surgery Transfusion Hemoglobin European Overview (OSTHEO) formula. We defined hidden blood loss (HBL) as the difference between the TBL and IBL. Pearson correlation, Spearman correlation, and multiple logistic regression analysis were performed to investigate the risk factors related to HBL.

RESULTS

Post-XLIF blood tests showed a significant decrease in the Hb (from 11.8 ± 1.1 mg/dl to 10.6 ± 1.1 mg/dl) and hematocrit (from 36.0 ± 3.2% to 32.5 ± 3.2%). Although the mean IBL was relatively small (33 ± 52 mL), we calculated the TBL as 291 ± 171 mL (Gross equation) and the HBL as 258 ± 168 mL by Gross equation, which was 8 times greater than the IBL on average. There was no difference in the results obtained using the three methods. Multiple logistic regression analysis indicated preoperative lumber lordosis was the risk factor of high HBL (Odds ratio = 1.085, 95%CI: 1.006-1.170, p = 0.035).

CONCLUSIONS

The HBL in XLIF was 8 times greater than the IBL. During the perioperative course of correction and fusion surgery for ASD with XLIF, surgeons need to pay attention not to underestimate the TBL.

Perioperative Hidden Blood Loss in Elderly Cervical Spondylosis Patients With Anterior Cervical Discectomy Fusion and Influencing Factors

Introduction:

To analyze the perioperative hidden blood loss (HBL) and its influencing factors in elderly cervical spondylosis patients treated with anterior cervical discectomy fusion (ACDF).

Materials and Methods:

From January 2017 to December 2018, 128 elderly cervical spondylosis patients (age > 65 y) treated with ACDF were selected. The patients’ height, weight, duration of symptoms, previous medical history and other basic information were routinely recorded. The hemoglobin (Hb), hematocrit (Hct) and blood coagulation function preoperative and the next day postoperative were recorded. The operation time, surgical bleeding, ASA classification, fixation method, total drainage and the time for extraction of drainage tube were recorded. The total blood loss (TBL) was calculated according to the Gross’s formula, and HBL was calculated based on TBL, total drainage and surgical bleeding. The statistical analysis of HBL was performed, and then influential factors were further analyzed by multivariate linear regression analysis and t test.

Results:

The mean surgical bleeding was 102.70 ± 46.78 mL and HBL was 487.98 ± 255.96 mL. HBL accounted for 67.61 ± 5.20% of TBL. According to the multiple linear regression analysis, the gender (P = 0.047), operation time (P = 0.000), fixation method (P = 0.014) and international normalized ratio (INR) (P = 0.003) influenced the amount of HBL. Body mass index (BMI) (P = 0.624), hypertension (P = 0.977), diabetes (P = 0.528), blood type (P = 0.577), ASA classification (P = 0.711), duration of symptoms (P = 0.661), preoperative cobb angle (P = 0.152), number of surgical level (P = 0.709), intramedullary hyperintensity (P = 0.967), drainage time (P = 0.294), postoperative drainage volume (P = 0.599), prothrombin time (PT) (P = 0.674), activated partial thromboplastin time (APTT) (P = 0.544) and thrombin time (TT) (P = 0.680) had no correlation with the amount of HBL.

Conclusions:

There was obvious HBL during the perioperative period of ACDF in elderly cervical spondylosis patients. The male patients, longer operation time, fusion with titanium plate and cage and high INR were independent risk factors for HBL.

Perioperative Hidden Blood Loss in Elderly Osteoporotic Vertebral Compression Fracture Patients With Percutaneous Vertebroplasty and Influencing Factors

Introduction

To analyze perioperative hidden blood loss (HBL) and its influencing factors in elderly patients with osteoporotic vertebral compression fracture (OVCF) treated with percutaneous vertebroplasty (PVP).

Materials and Methods

From January 2016 to December 2018, 103 elderly patients with OVCF (age > 85 years) treated with PVP were selected. The patient's height, weight, duration of symptoms, previous medical history and other basic information were recorded. The hemoglobin (Hb) and hematocrit (Hct) immediately after admission and the next day postoperative were recorded. The operation time, surgical bleeding, Kummell's disease, vertebral height preoperative and postoperative, and bone cement leakage was recorded. The total blood loss (TBL) was calculated according to Gross's formula, and HBL was calculated based on the TBL and surgical bleeding. The influential factors were analyzed by multivariate linear regression analysis and single factor correlation analysis.

Results

The mean surgical bleeding was 11.83 ± 5.37 mL, and HBL was 306.19 ± 185.92 mL, with a statistically significant difference (P = 0.000). According to the multiple linear regression analysis, the duration of symptoms (P = 0.030), number of fracture segments (P = 0.016), operation time (P = 0.004), loss of vertebral height (P = 0.026), recovery of vertebral height (P = 0.004), Kummell's disease (P = 0.040) and cement leakage (P = 0.004) were correlated with an increased amount of HBL. Sex (P = 0.077), body mass index (BMI) (P = 0.486), hypertension (P = 0.734), diabetes (P = 0.769), fracture level (P = 0.518) and surgical bleeding (P = 0.821) had no correlation with the amount of HBL.

Conclusions

There was obvious HBL during the perioperative period of PVP in elderly patients with OVCF. A fresh fracture, multi-segment vertebral fracture, longer operation time, presence of Kummell's disease, loss of vertebral height, recovery of vertebral height and cement leakage the increased perioperative HBL during PVP.

The hidden blood loss in proximal femur fractures is sizeable and significant

BACKGROUND

Patients sustaining hip fractures experience blood loss as a direct result the fracture independent of surgery. The objective of this study was to quantify the expected non-surgical blood loss for proximal femur fractures using hemoglobin values.

METHODS

A retrospective chart review of patients at a level 1 trauma center sustaining proximal femur fractures between October 2015 and January 2018 was performed. Patients were ≥30 years of age, had sustained intertrochanteric, subtrochanteric, or femoral neck fractures and had hemoglobin values documented at admission and after 12 h but before surgery. Patients with concomitant fractures, other hemorrhagic injuries, or blood transfusions before their second hemoglobin result were excluded. A multivariate linear regression model was constructed to evaluate the predictive ability of age, sex, BMI, number of comorbidities, fracture type, anticoagulation/antiplatelet therapy, admission hemoglobin, timing of surgical intervention and changes in electrolyte levels on subsequent hemoglobin values. Hemoglobin changes were compared between intertrochanteric, subtrochanteric, and femoral neck fractures and anticoagulant therapy types with Welch's tests.

RESULTS

119 patients were included. The mean age was 80.9 ± 10.81 years. Nearly 53% of subjects were using anticoagulation therapy. The mean drop in hemoglobin was 1.4 ± 1.03 g/dL. The multivariate linear regression model had statistically significant predictive ability (R = 0.91, p < 0.001). Independent predictors of hemoglobin decrease were number of comorbid conditions (p = 0.02), admission hemoglobin reading (p < 0.001), fracture type (p = 0.02), and time from admission to surgery (p = 0.03). Intertrochanteric fractures demonstrated the largest hemoglobin drops. Anticoagulation therapy had no effect on subsequent hemoglobin.

CONCLUSION

Proximal femur fractures cause a significant amount of blood loss prior to surgical intervention. Patients at particular risk include those with comorbidities, intertrochanteric fractures, low admission hemoglobin values, and increased time to surgery. The identification of demographic, fracture type, and treatment characteristics may help surgeons identify patients at the greatest risk for blood loss, and provide more effective perioperative care.

Hidden blood loss following 2- to 3-level posterior lumbar fusion

BACKGROUND CONTEXT

Patients undergoing single-level posterior lumbar decompression and fusion (PLDF) usually do not need transfusions. However, patients undergoing two or three-level PLDF occasionally require transfusion postoperatively even when estimated blood loss (EBL) or blood loss from drains appears acceptable. Estimating the volume of HBL is critical in perioperative fluid management.

PURPOSE

To determine the volume of hidden blood loss (HBL) in two- or three-level PLDF.

STUDY DESIGN

Single-center, multisurgeon, secondary analysis from a prospective randomized clinical trial of cell saver use.

PATIENT SAMPLE

Patients enrolled in a prospective randomized trial of cell saver undergoing two- or three-level PLDF were included in this analysis.

METHODS

Total blood loss was calculated using four estimation formulas including Bourke's, Gross', Camarasa's, and Lopez-Picado's formulas. HBL was determined by subtracting the visible loss (EBL and blood loss from drains) from the calculated total blood loss.

RESULTS

A total of 89 patients (36 males, mean age 62 years) were included. Seventy-five patients underwent open two-level fusion while 14 had three-level fusions. Intervertebral fusion was performed in 20 patients. Mean surgical time was 261 minutes, and EBL was 685 mL. Mean blood loss from drains was 824 mL. Seventy patients received allogenic blood whereas 47 cell saver blood reinfused intraoperatively. HBL was calculated to be 678 mL, 963 mL, 1,267 mL, and 819 mL using each formula.

CONCLUSIONS

HBL following two or three-level PLDF was substantial and more than EBL. Postoperative management of blood loss should take HBL into account.

Clinical feasibility and application value of computer virtual reduction combined with 3D printing technique in complex acetabular fractures

This study investigated the clinical feasibility and application value of computer virtual reduction combined with three-dimensional (3D) printing technique in patients with complex acetabular fracture. Ninety-six patients diagnosed with complex acetabular fracture in the Orthopedics Department in The Second Affiliated Hospital of Luohe Medical College from January 2016 to June 2017 were selected and randomly divided into the routine operation group (n=48) and the 3D model group (n=48) according to the admission number of the patients. In the 3D model group, computed tomography (CT) scan was performed preoperatively, and the model was made using the virtual technique and 3D printing technique. The surgical scheme was designed according to the model. Patients in the routine operation group were diagnosed with the conventional CT scan without using the computer virtual technique and 3D printing technique. During operation, the operation time, amount of intraoperative bleeding and times of intraoperative fluoroscopy were recorded in both groups. After operation, the incidence rate of such complications as inflammatory response, iatrogenic neurological symptoms and loss of reduction were recorded in both groups. Moreover, the reduction quality of acetabular fracture was evaluated according to the Matta imaging score at 3 days after operation, and the hip joint function was evaluated based on the Hariss score at 6 months after operation. In the 3D model group, the operation time was significantly shorter than that in the control group, the amount of intraoperative bleeding and times of intraoperative fluoroscopy were significantly less than those in the routine operation group, and the incidence rate of postoperative complications was obviously lower than that in the routine operation group (P<0.05). In conclusion, computer virtual reduction combined with the 3D printing technique can significantly reduce the operation time, amount of intraoperative bleeding, times of intraoperative fluoroscopy and incidence rate of postoperative complications without adverse effects on the reduction quality of acetabular fracture and hip joint function of patients, which has a higher clinical application value and greater social significance.