Tolerance of intraoperative hemoglobin decrease during cardiac surgery

Retrospective analysis of delta hemoglobin and bleeding-related risk factors in pancreaticoduodenectomy

BACKGROUND

Objective and accurate assessment of blood loss during pancreaticoduodenectomy (PD) is crucial for ensuring the safety and efficacy of the procedure. While the visual method remains the most common clinical metric, many scholars argue that it significantly differs from actual blood loss and is inherently subjective.

AIM

To assess blood loss in PD via delta hemoglobin (ΔHb) and compare it with the visual method to predict bleeding-related risk factors.

METHODS

In this retrospective analysis, 1722 patients who underwent PD from 2017 to 2022 at Shandong Provincial Hospital were divided into three groups: Open PD (OPD), laparoscopic PD (LPD), and conversion to OPD (CTOPD). Intraoperative ΔHb (IΔHb) was calculated via preoperative and 72-hour-postoperative hemoglobin concentrations, and its association with visually obtained estimated blood loss (EBL) was analyzed. Perioperative ΔHb (PΔHb) was calculated via preoperative and predischarge hemoglobin concentrations. We compared the differences in IΔHb and PΔHb among the three groups, and performed univariate and multivariate regression analyses of IΔHb and PΔHb.

RESULTS

The preoperative general information of patients showed no statistically significant difference among the three groups (P > 0.05). The IΔHb in the OPD, LPD, and CTOPD groups were 22.00 (12.00, 36.00), 21.00 (10.00, 33.00), and 33.00 (18.12, 52.24) g/L, respectively; And the PΔHb in the OPD, LPD, and CTOPD groups were 25.87 (13.51, 42.00), 25.00 (14.00, 45.00), and 37.48 (21.64, 59.65) g/L, respectively, values significantly differed (P < 0.05). IΔHb and EBL were significantly correlated (r = 0.337, P < 0.001). The results of univariate and multivariate regression analyses indicated that American Society of Anesthesiologists (ASA) classification IV [95% confidence interval (CI): 2.330-37.811, P = 0.049] and preoperative total bilirubin > 200 μmol/L (95%CI: 2.805-8.673, P < 0.001) were independent risk factors for IΔHb (P < 0.05), and ASA classification IV (95%CI: 45.934-105.485, P < 0.001), body mass index > 24 kg/m2 (95%CI: 1.285-9.890, P = 0.011), and preoperative total bilirubin > 200 μmol/L (95%CI: 6.948-16.797, P < 0.001) were independent risk factors for PΔHb (P < 0.05).

CONCLUSION

There is a correlation between IΔHb and EBL in PD, so we can assess the patients' intraoperative blood loss by the ΔHb method. ASA classification IV, body mass index > 24 kg/m², and preoperative total bilirubin > 200 μmol/L increased perioperative bleeding risk.

Hemoglobin decrease predicts untoward outcomes better than severity of anemia

Patients with gastrointestinal bleeding (GIB) exhibit varying tolerances to acute blood loss. We aimed to investigate the effect of relative Hb decrease (ΔHb%) on GIB outcomes. Participants enrolled in the Hungarian GIB Registry between 2019 and 2022 were analyzed. The primary outcome, defined as a composite endpoint, included in-hospital bleeding-related mortality and the need for urgent intervention. Four groups were created based on the lowest Hb measured during hospitalization (nadirHb), along with four subgroups categorized by ΔHb%. Regardless of the nadirHb, participants with higher ΔHb% had a higher probability of reaching the composite endpoint. A 30-40% ΔHb% decrease to a nadirHb of 80-90 g/L resulted in a similar likelihood of reaching the primary endpoint as a 0-10% ΔHb% to 70-80 g/L or 60-70 g/L, respectively (10% vs. 12%, p = 1.00; 10% vs. 10%, p = 1.00). Our results showed that a higher Hb decrease in GIB is associated with an increased untoward outcome rate even when the lowest hemoglobin exceeds the recommended transfusion thresholds. New randomized controlled trials investigating transfusion thresholds should consider ΔHb% as a potential key variable and risk factor.

Association between perioperative hemoglobin decrease and outcomes of transfusion in patients undergoing on-pump cardiac surgery: An observational study from two Chinese heart centers

Background

It is unclear how perioperative hemoglobin decrease (ΔHb) influences the balance between risks and benefits of red blood cell transfusion after cardiac surgery.

Methods

We retrospectively analyzed data on 8186 adults who underwent valve surgery and/or coronary artery bypass grafting under cardiopulmonary bypass at two large cardiology centers. We explored the potential association of ΔHb, defined relative to the preoperative level and postoperative nadir, with a composite outcome of in-hospital mortality, myocardial infarction, stroke, and acute kidney injury using multivariable logistic regression, restricted cubic spline, and piecewise-linear models.

Results

Among 6316 patients without preoperative anemia, ΔHb ≥ 50 % was associated with an elevated risk of the composite outcome [adjusted odds ratio (aOR) 1.95, 95 % confidence interval (CI) 1.81-2.35]. Among 869 patients without preoperative anemia and with ΔHb ≥ 50 %, postoperative transfusion of no more than four units of red blood cell appeared to decrease the risk of the composite outcome, whereas transfusion of more than six units increased risk. Among 5447 patients without preoperative anemia and with ΔHb < 50 %, postoperative transfusion appeared not to decrease the risk of the composite outcome. Among 1870 patients with preoperative anemia, ΔHb ≥ 30 % significantly increased the risk of the composite outcome (aOR 1.61, 95 % CI 1.23-2.10), and this risk might be moderated by postoperative transfusion of no more than four units of red blood cell, but increased by transfusion of more than six units.

Conclusions

ΔHb may influence the balance between risks and benefits of red blood cell transfusion after cardiac surgery.

Preoperative Anemia and Postoperative Outcomes in Cardiac Surgery: A Mediation Analysis Evaluating Intraoperative Transfusion Exposures

BACKGROUND

Preoperative anemia is associated with adverse outcomes in cardiac surgery, yet it remains unclear what proportion of this association is mediated through red blood cell (RBC) transfusions.

METHODS

This is a historical observational cohort study of adults undergoing coronary artery bypass grafting or valve surgery on cardiopulmonary bypass at an academic medical center between May 1, 2008, and May 1, 2018. A mediation analysis framework was used to evaluate the associations between preoperative anemia and postoperative outcomes, including a primary outcome of acute kidney injury (AKI). Intraoperative RBC transfusions were evaluated as mediators of preoperative anemia and outcome relationships. The estimated total effect, average direct effect of preoperative anemia, and percent of the total effect mediated through transfusions are presented with 95% confidence intervals and P -values.

RESULTS

A total of 4117 patients were included, including 1234 (30%) with preoperative anemia. Overall, 437 of 4117 (11%) patients went on to develop AKI, with a greater proportion of patients having preoperative anemia (219 of 1234 [18%] vs 218 of 2883 [8%]). In multivariable analyses, the presence of preoperative anemia was associated with increased postoperative AKI (6.4% [4.2%-8.7%] absolute difference in percent with AKI, P < .001), with incremental decreases in preoperative hemoglobin concentrations displaying greater AKI risk (eg, 11.9% [6.9%-17.5%] absolute increase in probability of AKI for preoperative hemoglobin of 9 g/dL compared to a reference of 14 g/dL, P < .001). The association between preoperative anemia and postoperative AKI was primarily due to direct effects of preoperative anemia (5.9% [3.6%-8.3%] absolute difference, P < .001) rather than mediated through intraoperative RBC transfusions (7.5% [-4.3% to 21.1%] of the total effect mediated by transfusions, P = .220). Preoperative anemia was also associated with longer hospital durations (1.07 [1.05-1.10] ratio of geometric mean length of stay, P < .001). Of this total effect, 38% (22%, 62%; P < .001) was estimated to be mediated through subsequent intraoperative RBC transfusion. Preoperative anemia was not associated with reoperation or vascular complications.

CONCLUSIONS

Preoperative anemia was associated with higher odds of AKI and longer hospitalizations in cardiac surgery. The attributable effects of anemia and transfusion on postoperative complications are likely to differ across outcomes. Future studies are necessary to further evaluate mechanisms of anemia-associated postoperative organ injury and treatment strategies.

A novel model for predicting a composite outcome of major complications after valve surgery

Background

On-pump valve surgeries are associated with high morbidity and mortality. The present study aimed to reliably predict a composite outcome of postoperative complications using a minimum of easily accessible clinical parameters.

Methods

A total of 7,441 patients who underwent valve surgery were retrospectively analyzed. Data for 6,220 patients at West China Hospital of Sichuan University were used to develop a predictive model, which was validated using data from 1,221 patients at the Second Affiliated Hospital of Zhejiang University School of Medicine. The primary outcome was a composite of major complications: all-cause death in hospital, stroke, myocardial infarction, and severe acute kidney injury. The predictive model was constructed using the least absolute shrinkage and selection operator as well as multivariable logistic regression. The model was assessed in terms of the areas under receiver operating characteristic curves, calibration, and decision curve analysis.

Results

The primary outcome occurred in 129 patients (2.1%) in the development cohort and 71 (5.8%) in the validation cohort. Six variables were retained in the predictive model: New York Heart Association class, diabetes, glucose, blood urea nitrogen, operation time, and red blood cell transfusion during surgery. The C-statistics were 0.735 (95% CI, 0.686-0.784) in the development cohort and 0.761 (95% CI, 0.694-0.828) in the validation cohort. For both cohorts, calibration plots showed good agreement between predicted and actual observations, and ecision curve analysis showed clinical usefulness. In contrast, the well-established SinoSCORE did not accurately predict the primary outcome in either cohort.

Conclusions

This predictive nomogram based on six easily accessible variables may serve as an "early warning" system to identify patients at high risk of major complications after valve surgery.

Clinical Trial Registration

[www.ClinicalTrials.gov], identifier [NCT04476134].

Impact of restrictive versus liberal transfusion and clinical outcomes in critically ill children: A retrospective observational study

Background and Aims

Critically ill children with anemia often requires blood transfusion, which can cause several complications. It is important to decide when to start the red blood cell (RBC) transfusion; however, the guidelines is still lacking. The aim of this study was to compare restrictive and liberal transfusion strategy.

Methods

This is an observational retrospective study of critically-ill children who receive RBC transfusion. Subjects categorized into two groups by initial hemoglobin (Hb), that is, restrictive (Hb ≤ 7 g/dl) and liberal (Hb ≤ 9.5 g/dl) strategy. In each group, subjects categorized based on: (1) Hb increment: high (increased ≥2.5 g/dl) and low (increase <2.5 g/dl) and (2) final Hb level: low (<7.0 mg/dl), moderate (7.0-10.0 mg/dl), and high (>10.0 mg/dl). Patient with hematologic or congenital disorder, severe malnutrition, chronic infection-related anemia, and transfusion in Hb level ≥9.5 g/dl were exclude. Each patients were evaluated for the clinical outcome, which is: intensive care length of stay (IC-LOS), length of mechanical ventilation (LoMV), and mortality rate.

Results

Clinical outcome and mortality rates of both transfusion strategies are similar. The mortality rates were lower in higher Hb increment and final Hb level (p = 0.04 and p = 0.01, respectively). Multivariate analysis in all groups revealed mortality rate had moderate correlation with Hb increment (odds ratio [OR] = 0.694, 95% confidence interval [CI] 0.549-0.878; p = 0.002) and moderate correlation (OR = 0.642, 95% CI 0.519-0.795; p = 0.000) with final Hb level. The similar results was found after categorization based on transfusion strategy.

Conclusion

We conclude the restrictive and liberal transfusion strategy have a similar effect to IC-LOS, LoMV, and mortality rate. High Hb increment (≥2.5 g/dl) and moderate-high final Hb (≥7.0 g/dl) after transfusion reduce the mortality rate.

Mortality and clinical outcome of Italian patients undergoing orthopaedic surgery: effect of peri-operative blood transfusion

BACKGROUND

Blood transfusion is a relevant issue for elderly and frail patients, as they are often anaemic and have chronic diseases. Transfusion of red blood cells (RBC) can potentially affect morbidity and mortality of elderly patients undergoing major orthopaedic surgery.

MATERIALS AND METHODS

We carried out a retrospective analysis of 2,593 patients undergoing major orthopaedic surgery between 2013 and 2017 in a single research institution in the Region of Apulia. The aims of the study were: 1) to describe the characteristics of transfused patients according to a restrictive or liberal strategy of transfusion and haemoglobin (Hb) triggers and targets; 2) to investigate the effect of RBC transfusion on mortality and complications.

RESULTS

Older, women and patients with American Society of Anesthesiologists (ASA) score 3-4 were more often transfused. Those with lower admission Hb level had a higher risk of being transfused. Hb triggers were associated with the patients' age. A restrictive transfusion strategy was significantly more frequent in patients undergoing primary knee replacement and in those with higher estimated blood loss. We did not observe any significant difference of complications in patients transfused with a liberal vs restrictive strategy. Logistic regression correcting for potential confounders revealed that sex (males more than females), duration of stay in hospital, hip fracture and Charlson score >4 were good predictors of complications and/or mortality. Mortality was significantly higher in males and in older patients with ASA score 3-4.

DISCUSSION

In this large cohort of Italian patients undergoing major orthopaedic surgery males were significantly more exposed than women to complications and in-hospital mortality. Furthermore, those undergoing urgent surgery because of hip fracture had a 3-fold higher chance of complications. Charlson score >4 and ASA 3-4 are good predictors of complications and mortality, respectively.

Anemia after Pediatric Congenital Heart Surgery

The postoperative course of infants following congenital heart surgery is associated with significant blood loss and anemia. Optimal transfusion thresholds for cardiac surgery patients while in pediatric intensive care unit (PICU) remain a subject of debate. The goal of this study is to describe the epidemiology of anemia and the transfusion practices during the PICU stay of infants undergoing congenital heart surgery. A retrospective cohort study was performed in a PICU of a tertiary university-affiliated center. Infants undergoing surgery for congenital heart disease (CDH) before 6 weeks of age between February 2013 and June 2019 and who were subsequently admitted to the PICU were included. We identified 119 eligible patients. Mean age at surgery was 11 ± 7 days. Most common cardiac diagnoses were d-Transposition of the Great Arteries (55%), coarctation of the aorta (12.6%), and tetralogy of Fallot (11.8%). Mean hemoglobin level was 14.3 g/dL prior to surgery versus 12.1 g/dL at the PICU admission. Hemoglobin prior to surgery was systematically higher than hemoglobin at the PICU entry, except in infants with Hypoplastic Left Heart Syndrome. The average hemoglobin at PICU discharge was 11.7 ± 1.9 g/dL. Thirty-three (27.7%) patients were anemic at PICU discharge. Fifty-eight percent of patients received at least one red blood cell (RBC) transfusion during PICU stay. This study is the first to describe the epidemiology of anemia at PICU discharge in infants following cardiac surgery. Blood management of this distinctive and vulnerable population requires further investigation as anemia is a known risk factor for adverse neurodevelopment delays in otherwise healthy young children.

Relative decrease in hemoglobin and outcomes in patients undergoing kidney transplantation surgery: A retrospective cohort study

BACKGROUND

Recent surgical literature suggests that a relative decrease in hemoglobin (ΔHb) is predictive of adverse outcomes regardless of the absolute level. We aimed to examine the association between perioperative ΔHb and kidney transplantation (KT) outcomes.

METHODS

This was a retrospective cohort study of transplant recipients, where ΔHb = [Hb0- Hb1Hb0]x 100 (Hb₀ = hemoglobin pre-KT and Hb₁ = lowest hemoglobin 24-h post-KT). The main outcome of interest was immediate graft function (IGF).

RESULTS

Of the 899 eligible patients, 38% experienced IGF, and ΔHb was associated with 36% lower odds of IGF. Also, ΔHb was associated with higher all-cause graft failure and longer length of stay but not death-censored graft failure or mortality. ΔHb ≥30% was the threshold beyond which the odds of IGF were significantly lower even if Hb₁ was ≥7 g/dL.

CONCLUSION

ΔHb is associated with inferior outcomes independent of Hb_1; whether it can be used to guide transfusion practices should be explored.

Intraoperative blood loss may be associated with myocardial injury after non-cardiac surgery

BACKGROUND

This study aimed to evaluate the association between intraoperative blood loss and myocardial injury after non-cardiac surgery (MINS), which is a severe and common postoperative complication.

METHODS

We compared the incidence of MINS based on significant intraoperative bleeding, defined as an absolute hemoglobin level < 7 g/dL, a relative hemoglobin level less than 50% of the preoperative measurement, or need for packed red cell transfusion. We also estimated a threshold for intraoperative hemoglobin level associated with MINS.

RESULTS

We stratified a total of 15,926 non-cardiac surgical patients with intraoperative hemoglobin and postoperative cardiac troponin (cTn) measurements according to the occurrence of significant intraoperative bleeding; 13,416 (84.2%) had no significant bleeding while 2,510 (15.8%) did have significant bleeding. After an adjustment with inverse probability weighting, the incidence of MINS was higher in the significant bleeding group (35.2% vs. 16.4%; odds ratio, 1.58; 95% confidence interval, 1.43-1.75; p < 0.001). The threshold of intraoperative hemoglobin associated with MINS was estimated to be 9.9 g/dL with an area under the curve of 0.643.

CONCLUSION

Intraoperative blood loss appeared to be associated with MINS. Further studies are needed to confirm these findings.

CLINICAL REGISTRATION

The cohort was registered before patient enrollment at https://cris.nih.go.kr (KCT0004244).

Postoperative Nadir Hemoglobin and Adverse Outcomes in Patients Undergoing On-Pump Cardiac Operation

BACKGROUND

Patients undergoing cardiac operation are susceptible to anemia. Low hemoglobin concentration is a risk factor for composite adverse events and death after cardiac operation. Here we investigated the association of postoperative nadir hemoglobin with adverse outcomes in patients undergoing on-pump cardiac operation.

METHODS

Adult patients in 2 medical centers were retrospectively analyzed. The primary outcome was postoperative composite adverse events. The secondary outcome was all-cause death in the hospital.

RESULTS

Of the 8206 patients analyzed, 1628 (19.8%) experienced composite adverse events after operation and 109 (1.3%) died. Patients receiving on-pump cardiac operation with nadir hemoglobin of 9.0 to 9.9 g/L showed a low incidence of composite adverse events (175 of 1423 [12.3%]) and death (5 of 1423 [0.4%]). Compared with nadir hemoglobin at 9.0 to 9.9 g/dL, the relative risk (RR) of composite adverse events increased stepwise as nadir hemoglobin fell below 9.0 g/dL: adjusted RR was 1.44 (95% confidence interval [CI], 1.14-1.83) for 8.5 to 8.9 g/dL, 1.56 (95% CI, 1.23-1.99) for 8.0 to 8.4 g/dL, 1.66 (95% CI, 1.31-2.11) for 7.5 to 7.9 g/dL, 2.22 (95% CI, 1.75-2.83) for 7.0 to 7.4 g/dL, and 4.00 (95% CI, 3.18-5.04) for less than 7 .0 g/dL. Furthermore, the risk of death was significantly higher when nadir hemoglobin was below 7.0 g/dL than when it was 9.0 to 9.9 g/dL (RR, 5.36; 95% CI, 2.20-16.12).

CONCLUSIONS

Compared with the risks when nadir hemoglobin is 9.0 to 9.9 g/dL, the risk of composite adverse events increases when postoperative nadir hemoglobin is below 9.0 g/dL, whereas risk of death increases when nadir hemoglobin is below 7.0 g/dL.

Perioperative Nadir Hemoglobin Concentration and Outcome in Off-Pump Coronary Artery Bypass Surgery - A Retrospective Review

BACKGROUND

Emerging evidence advocates the use of restrictive transfusion strategies at hemoglobin (Hb) levels of approximately 7-8 g/dL in cardiac surgeries using cardiopulmonary bypass. Yet, it is unclear whether the same thresholds can be applied to off-pump coronary bypass (OPCAB) that accompanies cardiac displacement and warm regional ischemia-reperfusion injury without the aid of a bypass machine. The aim of this study is to investigate the relationship between perioperative nadir Hb level and outcome following OPCAB.

METHODS AND RESULTS

Medical records of 1,360 patients were reviewed. Hb levels were serially assessed during and after surgery. The incidence of composite endpoints was 35%, which included myocardial infarction, stroke, acute kidney injury, sternal infection, reoperation, prolonged mechanical ventilation, and in-hospital mortality. The nadir Hb level was significantly lower in the morbidity group than in the non-morbidity group (8.1 [7.4-9.1] vs. 8.8 [7.9-9.8] g/dL, P<0.001). Multivariable logistic regression analysis revealed nadir Hb as an independent risk factor of adverse outcome (odds ratio: 0.878, 95% confidence intervals: 0.776-0.994, P=0.04), whereas preoperative anemia and perioperative transfusion were not. The critical value of Hb for predicting detrimental outcome was 8.05 g/dL.

CONCLUSIONS

A significant association is found between perioperative nadir Hb and adverse outcome after OPCAB. Although preoperative anemia was not associated with poor prognosisper se, it was the only modifiable risk factor that was closely linked to nadir Hb.

Transfusion of Red Blood Cells, Fresh Frozen Plasma, or Platelets Is Associated With Mortality and Infection After Cardiac Surgery in a Dose-Dependent Manner

BACKGROUND

It is unclear whether transfusion of platelets or fresh frozen plasma, in addition to red blood cells, is associated with an increased risk of mortality and infection after cardiac surgery.

METHODS

Patients who underwent valve surgery and/or coronary artery bypass grafting from January 1, 2011 to June 30, 2017 and September 1, 2013 to June 30, 2017 at 2 centers performing cardiac surgery were included in this retrospective study. After stratifying patients based on propensity score matching, we compared rates of mortality and infection between patients who transfused red blood cells, fresh frozen plasma, or platelets with those who did not receive such transfusions. We also compared outcomes between patients who received any of the 3 blood products and patients who received no transfusions at all. Multivariable logistic regression was used to assess associations between transfusion and outcomes.

RESULTS

Of 8238 patients in this study, 109 (1.3%) died, 812 (9.9%) experienced infection, and 4937 (59.9%) received at least 1 type of blood product. Transfusion of any blood type was associated with higher rates of mortality (2.0% vs 0.18%; P < .01) and infection (13.3% vs 4.8%; P < .01). Each of the 3 blood products was independently associated with an increase in mortality per unit transfused (red blood cells, odds ratio 1.18, 95% confidence interval [CI], 1.14-1.22; fresh frozen plasma, odds ratio 1.24, 95% CI, 1.18-1.30; platelets, odds ratio 1.12, 95% CI, 1.07-1.18). Transfusing 3 units of any of the 3 blood products was associated with a dose-dependent increase in the incidence of mortality (odds ratio 1.88, 95% CI, 1.70-2.08) and infection (odds ratio 1.50, 95% CI, 1.43-1.57).

CONCLUSIONS

Transfusion of red blood cells, fresh frozen plasma, or platelets is an independent risk factor of mortality and infection, and combination of the 3 blood products is associated with adverse outcomes after cardiac surgery in a dose-dependent manner.

Effect of postoperative haemoglobin variation on major cardiopulmonary complications in high cardiac risk patients undergoing anatomical lung resections

OBJECTIVES

Recent evidence shows that permissive anaemia strategies are safe in different surgical settings. However, effects of variations in haemoglobin (Hb) levels could have a negative impact in high-risk patients. We investigated the combined effect of postoperative Hb concentration and cardiac risk status on major cardiopulmonary complications after anatomical lung resections.

METHODS

We retrospectively analysed the records, collected in a prospective clinical database, of 154 consecutive patients undergoing anatomical lung resections at our institution (February 2017-February 2019). Hb levels were displayed as preoperative concentration, nadir Hb level before onset of complications and delta Hb (ΔHb). Cardiac risk was stratified according to the Thoracic Revised Cardiac Risk Index (ThRCRI). Univariable and multivariable logistic regression analyses were used to test the associations between patients, surgical variables and cardiopulmonary complications according to the European Society of Thoracic Surgeons definitions.

RESULTS

Cardiopulmonary complications occurred in 63 patients (17%). In the fully adjusted multivariable model, higher values of ΔHb were associated with increased risk of complications [odds ratio (OR) 1.07; P < 0.001], along with higher ThRCRI classes (classes A-B versus C-D: OR 0.09; P < 0.001). Interaction terms with transfusion were not statistically significant, indicating that the harmful effect of ΔHb was independent. According to receiver operating characteristic curve analysis, a ΔHb of 29 g/l was found to be the best cut-off value for predicting complications.

CONCLUSIONS

In our series, ΔHb, rather than nadir Hb, was associated with an increased risk of complications, particularly in patients with higher cardiac risk. Restrictive transfusion strategies should be carefully applied in patients undergoing lung resections and balanced according to individual clinical status.

The effect of various blood management strategies on intraoperative red blood cell transfusion in first-time coronary artery bypass graft patients

Effective blood management during cardiac surgery requires a multifactorial effort to limit exposure to allogeneic blood products. The present study evaluated the distribution of intraoperative interventions in patients undergoing coronary artery bypass graft surgery with cardiopulmonary bypass. Records from patients undergoing non-reoperative surgery at 120 hospitals between January 2017 and December 2017 were reviewed, and red blood cell transfusion quartiles established. The 31 hospitals with the lowest transfusion rates fell into the first quartile (low transfusion group, n = 3,186 patients), while 29 hospitals with the highest transfusion were in the fourth quartile (high transfusion group, n = 2,561). A survey was sent to assess the blood management techniques: acute normovolemic hemodilution, autologous prime, fluid management, intraoperative autotransfusion, ultrafiltration, and transfusion triggers. All data are presented as mean (standard deviation). Patients in the low transfusion group had red blood cell transfusion rate of 5.5%, while the high transfusion group was 28.3%. There was no difference in gender or age. Fluid management was reduced in the low transfusion group with smaller prime volumes and anesthesia volumes, but higher crystalloid use during cardiopulmonary bypass. The low transfusion group did not use acute normovolemic hemodilution as often and had lower sequestered volumes when used. When ultrafiltration was used, the low transfusion quartile group removed more volume (1,555.9 ± 955.2 vs. 1,326.1 ± 918.9 mL, p ⩽ 0.001). In the low transfusion group, nadir hematocrit on-cardiopulmonary bypass averaged 1.6% lower and 3.0% lower for transfusion post-cardiopulmonary bypass. Intraoperative red blood cell units averaged 0.11 ± 0.50 U in low transfusion group compared to 0.63 ± 1.14 U in the high transfusion group. Mixed-effects logistic regression identified first in operating room and first on cardiopulmonary bypass hematocrit, estimated blood volume and nadir hematocrit transfusion trigger as the strongest predictors for red blood cell transfusion. Significant variation exists in the transfusion of red blood cell in coronary artery bypass graft patients undergoing cardiopulmonary bypass which may be related to the application of intraoperative blood management techniques.

Greater anemia tolerance among hospitalized females compared to males

BACKGROUND

Although females have a lower baseline hemoglobin (Hb) compared to males, it is unknown whether females have a greater tolerance for anemia when hospitalized. We tested the hypothesis that females tolerate severe anemia better than males, with decreased inpatient mortality in this setting.

STUDY DESIGN AND METHODS

We conducted a retrospective cohort study in 230,644 adult patients admitted to Johns Hopkins Hospital from January 2009 to June 2016. The relationships between nadir Hb and percentage change in Hb with inpatient mortality were assessed for nontransfused males and females. A multivariable logistic regression was used to determine risk-adjusted differences between males and females for the likelihood of inpatient mortality at nadir Hb levels of 5, 6, and 7 g/dL.

RESULTS

Males had increased mortality when nadir Hb was 6.0 g/dL or less (p < 0.05), whereas females did not. The risk-adjusted likelihood for inpatient mortality was greater for males compared to females at a nadir Hb of 6 g/dL or less (odds ratio, 1.84; 95% confidence interval, 1.09-3.16) (p = 0.02), but this sex-related difference was not significant at a nadir Hb of 5 or 7 g/dL or less. Inpatient mortality increased significantly in both males and females when the percentage decrease in Hb was greater than 50% from baseline (p < 0.05).

CONCLUSIONS

Compared to males, females tolerate a lower nadir Hb, but a similar percentage change in Hb, before an increase in inpatient mortality is recognized. The findings suggest that females may be "preconditioned" to tolerate anemia better than males.

Prospective validation of the EuroSCORE II risk model in a single Dutch cardiac surgery centre

Objective

The EuroSCORE I was one of the most frequently used pre-operative risk models in cardiac surgery. In 2011 it was replaced by its successor the EuroSCORE II. This study aims to validate the EuroSCORE II and to compare its performance with the EuroSCORE I in a Dutch hospital.

Methods

The EuroSCORE II was prospectively validated in 2,296 consecutive cardiac surgery patients between 1 April 2012 and 1 January 2014. Receiver operating characteristic curves on in-hospital mortality were plotted for EuroSCORE I and EuroSCORE II, and the area under the curve was calculated to assess discriminative power. Calibration was assessed by comparing observed versus expected mortality. Additionally, analyses were performed in which we stratified for type of surgery and for elective versus emergency surgery.

Results

The observed mortality was 2.4% (55 patients). The discriminative power of the EuroSCORE II surpassed that of the EuroSCORE I (area under the curve EuroSCORE II 0.871, 95% confidence interval (CI) 0.832–0.911; area under the curve additive EuroSCORE I 0.840, CI 0.798–0.882; area under the curve logistic EuroSCORE I 0.761, CI 0.695–0.828). Both the additive and the logistic EuroSCORE I overestimated mortality (predictive mortality additive EuroSCORE I median 5.0%, inter-quartile range 3.0–8.0%; logistic EuroSCORE I 10.7%, inter-quartile range 5.8–13.9), while the EuroSCORE II underestimated mortality (median 1.6%, inter-quartile range 1.0–3.5). In most stratified analyses the EuroSCORE II performed better.

Conclusion

Our results show that the EuroSCORE II produces a valid risk prediction and outperforms the EuroSCORE I in elective cardiac surgery patients.

Recommendations on RBC Transfusion in General Critically Ill Children Based on Hemoglobin and/or Physiologic Thresholds From the Pediatric Critical Care Transfusion and Anemia Expertise Initiative

OBJECTIVES

To present the consensus recommendations and supporting literature for RBC transfusions in general critically ill children from the Pediatric Critical Care Transfusion and Anemia Expertise Initiative.

DESIGN

Consensus conference series of international, multidisciplinary experts in RBC transfusion management of critically ill children.

METHODS

The panel of 38 experts developed evidence-based and, when evidence was lacking, expert-based recommendations and research priorities regarding RBC transfusions in critically ill children. The subgroup on RBC transfusion in general critically ill children included six experts. Electronic searches were conducted using PubMed, EMBASE, and Cochrane Library databases from 1980 to May 30, 2017, using a combination of keywords to define concepts of RBC transfusion and critically ill children. Recommendation consensus was obtained using the Research and Development/UCLA Appropriateness Method. The results were summarized using the Grading of Recommendations Assessment, Development, and Evaluation method.

RESULTS

Three adjudicators reviewed 4,399 abstracts; 71 papers were read, and 17 were retained. Three papers were added manually. The general Transfusion and Anemia Expertise Initiative subgroup developed, and all Transfusion and Anemia Expertise Initiative members voted on two good practice statements, six recommendations, and 11 research questions; in all instances, agreement was reached (> 80%). The good practice statements suggest a framework for RBC transfusion in PICU patients. The good practice statements and recommendations focus on hemoglobin as a threshold and/or target. The research questions focus on hemoglobin and physiologic thresholds for RBC transfusion, alternatives, and risk/benefit ratio of transfusion.

CONCLUSIONS

Transfusion and Anemia Expertise Initiative developed pediatric-specific good practice statements and recommendations regarding RBC transfusion management in the general PICU population, as well as recommendations to guide future research priorities. Clinical recommendations emphasized relevant hemoglobin thresholds, and research recommendations emphasized a need for further understanding of physiologic thresholds, alternatives to RBC transfusion, and hemoglobin thresholds in populations with limited pediatric literature.

Percentage change in hemoglobin level and morbidity in spine surgery patients

OBJECTIVE

The aim of this study was to characterize the association between percentage change in hemoglobin (ΔHb)—i.e., the difference between preoperative Hb and in-hospital nadir Hb concentration—and perioperative adverse events among spine surgery patients.

METHODS

Patients who underwent spine surgery at the authors’ institution between December 4, 2008, and June 26, 2015, were eligible for this retrospective study. Patients who underwent the following procedures were included: atlantoaxial fusion, subaxial anterior cervical fusion, subaxial posterior cervical fusion, anterior lumbar fusion, posterior lumbar fusion, lateral lumbar fusion, excision of intervertebral disc, and excision of spinal cord lesion. Data on intraoperative transfusion were obtained from an automated, prospectively collected, anesthesia data management system. Data on postoperative hospital transfusions were obtained through an Internet-based intelligence portal. Percentage ΔHb was defined as: ([preoperative Hb − nadir Hb]/preoperative Hb) × 100. Clinical outcomes included in-hospital morbidity and length of stay associated with percentage ΔHb.

RESULTS

A total of 3949 patients who underwent spine surgery were identified. Of these, 1204 patients (30.5%) received at least 1 unit of packed red blood cells. The median nadir Hb level was 10.6 g/dl (interquartile range 8.7–12.4 g/dl), yielding a mean percentage ΔHb of 23.6% (SD 15.4%). Perioperative complications occurred in 234 patients (5.9%) and were more common in patients with a larger percentage ΔHb (p = 0.017). Hospital-related infection, which occurred in 60 patients (1.5%), was also more common in patients with greater percentage ΔHb (p = 0.001).

CONCLUSIONS

Percentage ΔHb is independently associated with a higher risk of developing any perioperative complication and hospital-related infection. The authors’ results suggest that percentage ΔHb may be a useful measure for identifying patients at risk for adverse perioperative events.

Gender disparities in red blood cell transfusion in elective surgery: a post hoc multicentre cohort study

OBJECTIVES

A post hoc gender comparison of transfusion-related modifiable risk factors among patients undergoing elective surgery.

SETTINGS

23 Austrian centres randomly selected and stratified by region and level of care.

PARTICIPANTS

We consecutively enrolled in total 6530 patients (3465 women and 3065 men); 1491 underwent coronary artery bypass graft (CABG) surgery, 2570 primary unilateral total hip replacement (THR) and 2469 primary unilateral total knee replacement (TKR).

MAIN OUTCOME MEASURES

Primary outcome measures were the number of allogeneic and autologous red blood cell (RBC) units transfused (postoperative day 5 included) and differences in intraoperative and postoperative transfusion rate between men and women. Secondary outcomes included perioperative blood loss in transfused and non-transfused patients, volume of RBCs transfused, perioperative haemoglobin values and circulating red blood volume on postoperative day 5.

RESULTS

In all surgical groups, the transfusion rate was significantly higher in women than in men (CABG 81 vs 49%, THR 46 vs 24% and TKR 37 vs 23%). In transfused patients, the absolute blood loss was higher among men in all surgical categories while the relative blood loss was higher among women in the CABG group (52.8 vs 47.8%) but comparable in orthopaedic surgery. The relative RBC volume transfused was significantly higher among women in all categories (CABG 40.0 vs 22.3; TKR 25.2 vs 20.2; THR 26.4 vs 20.8%). On postoperative day 5, the relative haemoglobin values and the relative circulating RBC volume were higher in women in all surgical categories.

CONCLUSIONS

The higher transfusion rate and volume in women when compared with men in elective surgery can be explained by clinicians applying the same absolute transfusion thresholds irrespective of a patient's gender. This, together with the common use of a liberal transfusion strategy, leads to further overtransfusion in women.

Impact of Delta Hemoglobin on Provider Transfusion Practices and Post-operative Morbidity Among Patients Undergoing Liver and Pancreatic Surgery

BACKGROUND

Delta hemoglobin (ΔHb) is defined as the difference between the preoperative Hb and the lowest post-operative Hb level. We sought to define the impact of ΔHb relative to nadir Hb levels on the likelihood of transfusion, as well as characterize the impact of ΔHb and nadir Hb on morbidity among a large cohort of patients undergoing complex hepatopancreatobiliary (HPB) surgery.

METHODS

Patients who underwent pancreatic or hepatic resection between January 1, 2009 and June 30, 2015 at Johns Hopkins Hospital were identified. Data on the perioperative ΔHb, nadir Hb, as well as blood utilization were obtained and analyzed. Multivariable logistic regression models were used to identify the factors associated with ΔHb and the impact of ΔHb on perioperative morbidity. A Bayesian model was used to evaluate the correlation of ΔHb and nadir Hb with the likelihood of transfusion, as well as the impact on morbidity.

RESULTS

A total of 4363 patients who underwent hepatobiliary (n = 2200, 50.4 %) or pancreatic (n = 2163, 49.6 %) surgery were identified. More than one quarter of patients received at least one unit of packed red blood cells (PRBC) (n = 1187, 27.2 %). The median nadir Hb was 9.2 (IQR 7.9-10.5) g/dL resulting in an average ΔHb of 3.4 mg/dL (IQR 2.2-4.7) corresponding to 26.3 %. Both ΔHb and nadir Hb strongly influenced provider behavior with regards to use of transfusion. Among patients with the same nadir Hb, ΔHb was strongly associated with use of transfusion; among patients who had a nadir Hb ≤6 g/dL, the use of transfusion was only 17.9 % when the ΔHb = 10 % versus 49.1 and 80.9 % when the ΔHb was 30 or 50 %, respectively. Perioperative complications occurred in 584 patients (13.4 %) and were more common among patients with a higher value of ΔHb, as well as patients who received PRBC (both P < 0.001).

CONCLUSIONS

The combination of the Hb trigger with ΔHb was associated with transfusion practices among providers. Larger ΔHb values, as well as receipt of transfusion, were strongly associated with risk of perioperative complication following HPB surgery.

Point-of-care diagnostics for niche applications

Point-of-care or point-of-use diagnostics are analytical devices that provide clinically relevant information without the need for a core clinical laboratory. In this review we define point-of-care diagnostics as portable versions of assays performed in a traditional clinical chemistry laboratory. This review discusses five areas relevant to human and animal health where increased attention could produce significant impact: veterinary medicine, space travel, sports medicine, emergency medicine, and operating room efficiency. For each of these areas, clinical need, available commercial products, and ongoing research into new devices are highlighted.