Nadir Hb Research Articles

Transfusion in Anemic Patients with Acute Coronary Syndromes: A Population-Based Cohort Study

BackgroundThere is controversy surrounding the effectiveness of red blood cell (RBC) transfusion for treating anemia in patients hospitalized for acute coronary syndromes (ACS), particularly as hemoglobin levels (Hb) approach and drop below the range of moderate anemia. MethodsThis population-based cohort study followed all adults hospitalized for ACS who experienced an in-hospital nadir Hb between 6.0-8.9g/dL between April 1, 2012 to March 31, 2021 in Ontario, Canada. Patients were excluded if they underwent coronary artery bypass graft surgery or had history of dementia, palliative care, or long-term care. Transfused patients were compared to non-transfused patients. The primary outcome was a composite of all-cause death and hospitalization for myocardial infarction (MI) within 30-days of hospital discharge. Overlap propensity score weighting was used to account for confounding and to emphasize the comparison in patients for whom there is clinical equipoise. ResultsThis study included 7,922 patients, of whom 3,498 were transfused and 4,424 were not transfused. In the propensity weighted cohort, the mean nadir Hb for each group was 7.75g/dL. The 30-day cumulative incidence rate for the primary outcome after application of propensity score weights was 28.6% in the transfusion group and 33.3% in the no-transfusion group (hazard ratio [HR]: 0.83, 95% confidence interval [CI] 0.75-0.91), which persisted at 1-year after hospital discharge and across sensitivity analyses. ConclusionsIn patients hospitalized for ACS who experience nadir Hb levels between 6.0-8.9g/dL, RBC transfusion was associated with a reduction in the composite event of all-cause death and hospitalization for MI within 30-days after hospital discharge.

Ultrafiltration During Cardiac Surgery Requiring Cardiopulmonary Bypass and Its Effect on Acute Kidney Injury

To explore whether ultrafiltration (UF) volume adjusted for weight is associated with an increased risk of acute kidney injury (AKI) after cardiopulmonary bypass (CPB) in cardiac surgery patients. A retrospective cohort study. Single-center study at a tertiary academic medical center. A total of 2369 adult patients (age ≥18 years) who underwent cardiac surgery with CPB between January 2018 and August 2019. The cohort was divided into 4 groups based on weight-adjusted conventional UF volume: 0 (no UF), 0.1 to 17.9 mL, 18 to 29.9 mL, and >30 mL ultrafiltration for each kg of body weight. Demographic data, laboratory findings, comorbidities, medications, and surgical details were collected. Postoperative AKI was defined by the KDIGO (Kidney Disease: Improving Global Outcomes) staging criteria and assessed in all UF groups. The association between UF volume and AKI according to nadir hemoglobin (Hb) level and red blood cell transfusion volume was explored. Postoperative AKI occurred in 840 patients (35.4%). The incidence of AKI post-CPB in patients was similar in patients with 0 mL/kg (34.4%; n = 123), 0.1 to 17.9 mL/kg (34.3%; n = 387), and 18 to 29.9 mL/kg (33.7%; n = 173) of UF volume. The patients with UF volume >30 mL/kg had a higher incidence of AKI (42.7%; n = 157; p = 0.019). For each additional 10 mL/kg increase in UF, the odds ratio (OR) of AKI was 1.14 (95% confidence interval [CI], 1.07-1.20; p < 0.001) following adjustments for preoperative covariates. However, the association was mitigated following adjustments for preoperative and intraoperative covariates (OR, 1.07; 95% CI, 0.99-1.16; p = 0.076). Although higher UF also was associated with an increased risk of AKI in patients with nadir Hb levels of 6 to 8 g/dL (adjusted OR, 1.24 and 1.22; p = 0.02), it was not significantly associated with AKI when nadir Hb was 10 to 12 g/dL. Red blood cell transfusion volume was not related to changes in AKI incidence. This study suggests that conventional UF is a potential risk factor for AKI incidence following surgery with CPB. The results demonstrate an association between higher weight-adjusted ultrafiltration volume and a higher incidence of AKI. Future studies should incorporate a multicenter, prospective approach to test the generalizability of the present findings and validate modified ultrafiltration strategies that use hemodynamic variables to determine fluid removal volume.

Impact of perioperative hemoglobin-related parameters on clinical outcomes in patients with spinal metastases: identifying key markers for blood management.

Patients with spinal metastases undergoing surgical treatment face challenges related to preoperative anemia, intraoperative blood loss, and frailty, emphasizing the significance of perioperative blood management. This retrospective analysis aimed to assess the correlation between hemoglobin-related parameters and outcomes, identifying key markers to aid in blood management. A retrospective review was performed to identify patients who underwent surgical treatment for spinal metastases. Hb-related parameters, including baseline Hb, postoperative nadir Hb, predischarge Hb, postoperative nadir Hb drift, and predischarge Hb drift (both in absolute values and percentages) were subjected to univariate and multivariate analyses. These analyses were conducted in conjunction with other established variables to identify independent markers predicting patient outcomes. The outcomes of interest were postoperative short-term (6-week) mortality, long-term (1-year) mortality, and postoperative 30-day morbidity. A total of 289 patients were included. Our study demonstrated that predischarge Hb (OR 0.62, 95% CI 0.44-0.88, P = 0.007) was an independent prognostic factor of short-term mortality, while baseline Hb (OR 0.76, 95% CI 0.66-0.88, P < 0.001) was identified as an independent prognostic factor of long-term mortality. Additionally, nadir Hb drift (OR 0.82, 95% CI 0.70-0.97, P = 0.023) was found to be an independent prognostic factor for postoperative 30-day morbidity. This study demonstrated that predischarge Hb, baseline Hb, and nadir Hb drift are prognostic factors for outcomes. These findings provide a foundation for precise blood management strategies. It is crucial to consider Hb-related parameters appropriately, and prospective intervention studies addressing these markers should be conducted in the future.

Nadir Hemoglobin Concentration After Spinal Tumor Surgery: Association With Risk of Composite Adverse Events.

Retrospective case-control study. To explore the association of early postoperative nadir hemoglobin with risk of a composite outcome of anemia-related and other adverse events. We retrospectively analyzed data from spinal tumor patients who received intraoperative blood transfusion between September 1, 2013 and December 31, 2020. Uni- and multivariate logistic regression was used to explore relationships of clinicodemographic and surgical factors with risk of composite in-hospital adverse events, including death. Subgroup analysis explored the relationship between early postoperative nadir hemoglobin and composite adverse events. Among the 345 patients, 331 (95.9%) experienced early postoperative anemia and 69 (20%) experienced postoperative composite adverse events. Multivariate logistic regression analysis showed that postoperative nadir Hb (OR = .818, 95% CI: .672-.995, P = .044), ASA ≥3 (OR = 2.007, 95% CI: 1.086-3.707, P = .026), intraoperative RBC infusion volume (OR = 1.133, 95% CI: 1.009-1.272, P = .035), abnormal hypertension (OR = 2.199, 95% CI: 1.085-4.457, P = .029) were correlated with composite adverse events. The lumbar spinal tumor was associated with composite adverse events with a decreased odds compared to thoracic spinal tumors (OR = .444, 95% CI: .226-.876, P = .019). Compared to patients with postoperative nadir hemoglobin ≥11.0g/dL, those with nadir <9.0g/dL were at significantly higher risk of postoperative composite adverse events (OR = 2.709, 95% CI: 1.087-6.754, P = .032). Nadir hemoglobin <9.0g/dL after spinal tumor surgery is associated with greater risk of postoperative composite adverse events in patients who receive intraoperative blood transfusion.

Management and clinical outcomes for patients with gastrointestinal bleeding who decline transfusion.

The national blood shortage and growing patient population who decline blood transfusions have created the need for bloodless medicine initiatives. This case series describes the management of gastrointestinal bleed patients who declined allogeneic blood transfusion. Understanding the effectiveness of bloodless techniques may improve treatment for future patients while avoiding the risks and cost associated with transfusion. A retrospective chart review identified 30 inpatient encounters admitted between 2016 to 2022 for gastrointestinal hemorrhage who declined transfusion due to religious or personal reasons. Clinical characteristics and patient blood management methods utilized during hospitalization were analyzed. Hemoglobin concentrations and clinical outcomes are reported. The most common therapy was intravenous iron (n = 25, 83.3%), followed by erythropoietin (n = 18, 60.0%). Endoscopy was the most common procedure performed (n = 23, 76.7%), and surgical intervention was less common (n = 4, 13.3%). Pre-procedure hemoglobin was <6 g/dL in 7 patients, and <5 g/dL in 4 patients. The median nadir hemoglobin was 5.6 (IQR 4.5, 7.0) g/dL, which increased post-treatment to 7.3 (IQR 6.2, 8.4) g/dL upon discharge. One patient (3.3%) with a nadir Hb of 3.7 g/dL died during hospitalization from sepsis. Nine other patients with nadir Hb <5 g/dL survived hospitalization. Gastrointestinal bleed patients can be successfully managed with optimal bloodless medicine techniques. Even patients with a nadir Hb <5-6 g/dL can be stabilized with aggressive anemia treatment and may safely undergo anesthesia and endoscopy or surgery for diagnostic or therapeutic purposes. Methods used for treating bloodless medicine patients may be used to improve clinical care for all patients.

Effectiveness of Robotic Arm-Assisted Total Knee Arthroplasty on Transfusion Rate in Staged Bilateral Surgery.

The transfusion rate in staged bilateral total knee arthroplasty (TKA) remains high despite the application of blood management techniques. The potential of robotic arm-assisted TKA (R-TKA) in reducing the transfusion rate in staged bilateral surgery has not yet been investigated. Therefore, we aimed to evaluate the effectiveness of R-TKA on transfusion reduction compared with conventional TKA (C-TKA) in staged bilateral surgery. This retrospective study involved two groups of patients who underwent 1-week interval staged bilateral TKA-the C-TKA group and the R-TKA group-using MAKO SmartRobotics (Stryker, Kalamazoo, MI, USA). Each group comprised 53 patients after propensity score matching and was compared in terms of nadir hemoglobin (Hb) level and transfusion rate after each stage of surgery. Both groups showed no significant differences in the propensity-matched variables of age, sex, body mass index, American Society of Anesthesiologists physical status score, and preoperative Hb level. The R-TKA group showed a significantly higher nadir Hb level than the C-TKA group after the second TKA (p = 0.002). The transfusion rate was not significantly different between the two groups after the first TKA (p = 0.558). However, the R-TKA group showed a significantly lower transfusion rate in the TKA (p = 0.030) and overall period (p = 0.023) than the C-TKA group. Patients who undergo staged bilateral R-TKA have lower transfusion rate than those who undergo C-TKA. R-TKA may be effective in minimizing unnecessary allogeneic transfusions in staged bilateral surgery.

Abstract 6181: Dynamic changes in monocyte and reticulocyte counts predict mechanism-based anemia development and recovery during ATR inhibitor treatment in phase I/II trials

Abstract Introduction: Clinical trials are exploring ATR inhibitors (ATRi) in genomically selected contexts. However, dose-dependent anemia has limited the therapeutic index of this class. We hypothesized that monocytes and reticulocytes are more vulnerable to ATRi due to their lack of base excision repair and high levels of oxidative stress, respectively. We sought to examine the kinetics of decline and recovery of red blood cell (RBC) and reticulocyte indices, in relation to hemoglobin (Hb), in the first 28 days after ATRi initiation. Methods: We retrospectively retrieved peripheral blood cell indices from complete blood count (CBC) reports of patients (pts) pre- and during treatment with an oral ATRi on phase I/II trials at our center. Pts received ATRi monotherapy or in combination with a PARP inhibitor (ATRi+PARPi) in dose-escalation and expansion cohorts, which included ATRi at potentially toxic doses. We applied linear mixed effect models to evaluate the joint evolution of Hb and other RBC or reticulocyte indices over time via bivariate analysis. A random intercept was included in the model to account for the longitudinal nature of the data and a variance component option for the covariance structure was specified to model a different variance component for each index of interest. To assess if Hb decline was preceded by decline in the index of interest from baseline, piecewise regression models were used to estimate break points, defined as the time point where the fitted functions intersect, of each index. Log transformed data with a base of 2, were noted to have more symmetric distributions, and were used in the analyses. The time variable assessed was days from cycle 1 day 1 of ATRi. A two-sided p value &amp;lt;0.05 was considered statistically significant. Results: 35,007 indices from 1,843 CBC of 119 pts treated with an ATRi from 10/2017 to 1/2022 were analyzed. 110 (92.4%) pts received ATRi, 9 (7.6%) received ATRi+PARPi. Monocytes (-0.120 vs -0.022, p &amp;lt;0.0001) and reticulocytes (-0.140 vs -0.022, p &amp;lt;0.0001) declined at a faster rate compared with Hb. Time to monocyte and reticulocyte nadir after ATRi initiation was 8.9 and 5.8 days, respectively, while time to Hb nadir was 19.5 days. Conversely, RBC (-0.020 vs -0.023, p=0.410), MCV (-0.002 vs -0.022, p &amp;lt;0.0001) and MCH (-0.001 vs -0.022, p&amp;lt;0.0001) declined at a slower rate than Hb. Time to RBC, MCV and MCH nadir after ATRi initiation was 26.3, 18.7 and 15.0 days, respectively. After reaching their individual index nadir, monocytes (0.004 vs 0.001, p &amp;lt;0.0001) and reticulocytes (0.005 vs 0.0005, p &amp;lt;0.0001) increased more quickly than Hb. Conclusions: Charting the kinetics of CBC index evolution in relation to Hb identified peripheral monocytes and reticulocytes as relevant blood indices that herald Hb decline. Our findings may inform patient monitoring strategies to mitigate hematologic toxicity on future ATRi trials. Citation Format: Natalie Y. Ngoi, Heather Y. Lin, Ecaterina Dumbrava, Siqing Fu, Daniel D. Karp, Aung Naing, Shubham Pant, Sarina A. Piha-Paul, Jordi Rodon, Vivek Subbiah, Apostolia M. Tsimberidou, Erick Campbell, Samuel Urrutia, David S. Hong, Funda Meric-Bernstam, Ying Yuan, Timothy A. Yap. Dynamic changes in monocyte and reticulocyte counts predict mechanism-based anemia development and recovery during ATR inhibitor treatment in phase I/II trials. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 6181.

Association of Postoperative Drift in Hemoglobin With Mortality After Brain Tumor Craniotomy.

Postoperative downward drift in hemoglobin (Hb) concentration may be associated with complications and death, even if nadir Hb remains more than the red blood cell transfusion threshold of 7 g/dL. To assess whether postoperative Hb drift in patients undergoing brain tumor craniotomy influences mortality in the immediate perioperative period. This retrospective cohort study included patients undergoing craniotomy for brain tumors. We defined no postoperative Hb decrease, mild decrease, moderate decrease, and severe decrease as postoperative Hb drift of ≤25%, 26% to 50%, 51% to 75%, and >75%, respectively. The primary outcome was 30-day mortality after craniotomy. This study included 8159 patients who underwent a craniotomy for brain tumors. Compared with patients with no postoperative Hb drift, the odds of postoperative mortality at 30 days increased in patients with mild postoperative Hb drift (adjusted odds ratio [OR] 2.47, 95% CI 1.72-3.56), moderate drift (adjusted OR 6.56, 95% CI 3.42-12.59), and severe drift (adjusted OR 12.33, 95% CI 3.48-43.62). When postoperative Hb drift was analyzed as a continuous variable, for each 10% increase in Hb drift, the adjusted OR of postoperative mortality at 30 days was 1.46 (95% CI 1.31-1.63). In patients undergoing brain tumor craniotomy, a small postoperative Hb drift was associated with increased odds of postoperative mortality at 30 days, even if the nadir Hb level remained greater than the red blood cell transfusion threshold of 7 g/dL. Future randomized clinical trials of perioperative transfusion practices may examine the effect of both nadir Hb and Hb drift.

Effectiveness of transarterial embolisation for intractable postpartum haemorrhage in a disseminated intravascular coagulation state, despite emergency hysterectomy

We evaluated the effectiveness of transarterial embolization (TAE) for intractable postpartum hemorrhage in patients with disseminated intravascular coagulation (DIC) despite emergency hysterectomy. We retrospectively assessed TAE performed after emergency hysterectomy in 15 patients between July 2008 and January 2022. Underlying condition, technical success, clinical success, angiographic findings, laboratory findings, pregnancy-modified DIC score (The International Society on Thrombosis and Haemostasis), blood transfusion, ICU (Intensive care unit) admission day, hospital day, in-hospital mortality, and long-term sequelae were evaluated. All patients were diagnosed with DIC before embolization, with a 43.9 mean DIC score. All patients showed positive angiographic findings for active bleeding. Thirty-eight bleeding arteries were confirmed. The remnant uterine artery (n=25) was the most common focus of persistent bleeding, followed by the cervicovaginal artery (n=6), pudendal artery (n=3), obturator artery (n=2), vesical artery (n=1), and unspecified artery from the internal iliac artery (n=1). Technical and clinical success rates were 100% (15/15) and 93.3% (14/15), respectively. Mean nadir hemoglobin (Hb) level before embolization was 4.9 g/dL. All patients underwent massive transfusion before embolization (mean 33.2 packs of RBC). Postoperatively, a smaller amount of blood was transfused than before the procedure (mean 10.6 packs of RBC). Mean nadir Hb level after embolization was 8.2 g/dL. There was one instance each of in-hospital death, hypoxic brain damage, and ischemic acute kidney injury. Despite hysterectomy for postpartum bleeding, there could be multiple residual or uncontrolled bleeding foci, especially in case of DIC, for which TAE could be an effective treatment.

Racial differences in red blood cell transfusion in hospitalized patients with anemia.

BackgroundGuidelines recommend transfusion of red blood cells (RBC's) when a hospitalized patient's hemoglobin (Hb) drops below a restrictive transfusion threshold, either at 7 or 8 g. Hospitals have implemented transfusion policies to encourage compliance with guidelines and reduce variation in transfusion practice. However, variation in transfusion practice remains. The purpose of this study was to examine whether there is variation in the receipt of transfusion by patient race.MethodsHospitalized general medicine patients with anemia (Hb < 10 g/dL) were eligible. Chi‐squared tests were used to compare the percent of patients receiving a transfusion by race overall and within strata of their nadir Hb. Linear regression was used to test the association between a patient's race, their nadir Hb, receipt of an RBC transfusion, and the number of units transfused.ResultsFour thousand nine hundred and fifty‐one patients consented, including 1363 (28%) who received a transfusion. 71% of patients were African American, 25% were White, and 4% were Other Race. Overall African Americans were less likely to be transfused compared to Whites (25% vs. 30%, p < .01), and within Hb strata below a Nadir Hb of 9 g/dL (Hb 8.0–8.9 g/dL 1% vs. 7%, p < .01; 7.0–7.9 g/dL 15% vs. 28%, p < .01; <7 g/dL 80% vs. 86%, p < .01). African Americans also received fewer units of RBC's (β = −.17, p < .01) overall and at lower Hb levels (β = .14, p < .01) compared to Whites.DiscussionThe Hb level at which patients are transfused at and the total number of RBC units received during hospitalization differ by patient race.

Hematemesis From Varices in a 14-year-old Without Hepatobiliary Disease: A "Wandering" Diagnosis.

Hematemesis From Varices in a 14-year-old Without Hepatobiliary Disease: A "Wandering" Diagnosis.

Investigating the association between blood transfusion and clinical outcomes in patients with acute coronary syndromes: a data linkage approach to Patient Blood Management.

The appropriateness of the use of blood transfusion in patients with acute coronary syndromes (ACS) remains contested. In general, studies addressing this issue were based on data from clinical trials, registries, or electronic medical records, and were conducted across different settings. Our study aimed to use a linked patient blood management data system from existing hospital databases to examine the association between blood transfusion and in-hospital mortality, length of stay (LOS) and readmission rates among patients with ACS, and to investigate this relationship at different haemoglobin (Hb) concentrations. This was a retrospective observational study of patients admitted to participating hospitals between 1st January 2014 to 31st December 2017 with ACS recorded as primary diagnosis. Admission and nadir Hb concentrations were categorised as ≤100 g/L and >100 g/L. Generalised estimating equations were used to investigate the association between transfusion and clinical outcomes, while accounting for the correlation of multiple admissions from the same patients across hospitals over the study period. Of the 9,952 admissions included, blood transfusions occurred in 705 (7.1%). In unadjusted analyses, transfusion was associated with an increased risk of in-hospital mortality (OR: 2.97; 95% CI: 2.14-4.13) and an average LOS 3.55 (95% CI: 3.38-3.72) times longer. After adjusting for demographic and clinical factors, transfusion was associated with an increased risk of in-hospital mortality when Hb >100 g/L. Transfusion was not associated with the risk of readmission. The effect of transfusion on in-hospital mortality was largely dependent on the pre-transfusion Hb concentration. When Hb was >100 g/L transfusion was associated with increased mortality, whereas when Hb ≤100 g/L no association was observed.

Perioperative anemia predicts kidney injury after partial nephrectomy.

PurposePartial nephrectomy (PN) induced kidney injury is still a challenging clinical matter that has not been completely conquered. This study aimed to explore the influences of perioperative anemia on renal function after PN.Materials and MethodsA total of 114 patients undergoing PN were retrospectively studied. Serum creatinine was tested preoperatively and 24 hours and 3 days after PN to evaluate the occurrence of acute kidney injury (AKI). Perioperative anemia was evaluated on the basis of the hemoglobin (Hb) value at 24 hours and 3 days postoperation. Patients were then followed up for the development of chronic kidney disease (CKD). Associations between perioperative anemia and postoperative AKI and CKD were determined.ResultsThe cumulative incidence of perioperative anemia was 33.33% in the study. A total of 32.46% of patients suffered from postoperative AKI, and 16.67% of patients progressed to CKD. The incidences of AKI and CKD in perioperative anemia patients were dramatically exceeded in those without anemia. Further statistical analyses indicated that perioperative anemia was a relevant factor for postoperative kidney injury, presenting the highest odds ratio of 31.272 for postoperative AKI and 17.179 for postoperative CKD. Receiver operating characteristic curve analysis showed that ΔHb=(preoperative Hb)-(postoperative Hb nadir) was a meaningful predictor of postoperative kidney injury, with an area under the curve of 0.784 for predicting postoperative AKI and 0.805 for postoperative CKD.ConclusionsPerioperative anemia can predict kidney injury after PN, and ΔHb shows a meaningful predictive value for postoperative AKI and CKD.

Pregnancy-Associated Autoimmune Hemolytic Anemia: Meta-Analysis of Clinical Characteristics, Maternal and Neonatal Outcomes

▪Introduction: Autoimmune hemolytic anemia (AIHA) is a rare condition that can cause potentially serious complications in pregnant women and newborns. With the lack of prospective trials, physicians often have to make treatment decisions for this vulnerable population based on scarce literature with poor evidence. We sought to summarize existing literature and analyze maternal and neonatal outcomes in pregnancy-associated AIHA (p-AIHA).Methods: Cases of AIHA in pregnancy were collected using MEDLINE/PubMed and Google Scholar literature search using terms “autoimmune hemolytic anemia” and “pregnancy”. Bibliography of each article was hand-searched for additional reports. Only publications in English were included. Cases of preexisting AIHA, autoimmune disease associated AIHA, non-immune hemolysis, and cases where direct antiglobulin testing (DAT) was not performed, were excluded. Laboratory, obstetric, neonatal and treatment data were collected. Data were analyzed using descriptive statistics. We used Wilcoxon rank sum test for continuous variables and Fisher's exact test for categorical variables. When missing data were encountered, we reported a valid number of analyzed patients in parentheses.Results: We identified 87 cases of p-AIHA from case reports, case series, abstracts and posters. Final analysis included 51 individual women. Median age at p-AIHA presentation was 28 years. Presentation was less common in the first pregnancy (34%); most cases presented in the second or third trimester (83.3%).Median nadir hemoglobin (Hb), lactate dehydrogenase, total bilirubin and peak reticulocyte count were 5.8 g/dL, 457 U/L, 2.2, and 13.6%, respectively. DAT negative hemolysis was reported in 41% of cases (Table 1). DAT positivity was not associated with pregnancy trimester, hemolysis severity, response to steroids, AIHA recurrence, adverse pregnancy outcomes, or hemolysis in newborn. There was a trend for longer duration of hemolysis postpartum in women with positive DAT compared to negative DAT (10 vs 2 weeks, p = 0.08). Median duration of hemolysis postpartum was 6 weeks (n=27, range 0-96 weeks). Two thirds of women were treated with steroids with hemoglobin response of 88.9% (n=27). There was no association between steroid use and duration of hemolysis postpartum. Blood transfusion was administered in 27 out of 33 women, with a median number of units transfused 5. Recurrent p-AIHA was seen in 40% (12/30) of women; there was no difference in nadir Hb levels for those with recurrent p-AIHA vs. not recurrent (6.8 vs 5.2 g/dL, p=0.11).Pregnancy resulted in term delivery in 61.9%, preterm delivery in 23.8%, and stillbirth in 9.5% (n=42). Adverse pregnancy outcomes, which included preterm labor and stillbirth, were reported in 50% of women who presented in the first or second trimester compared to 16% who presented in the third trimester (p=0.049, Table 2).Women with adverse pregnancy outcomes had significantly lower median nadir hemoglobin compared to women without adverse pregnancy outcomes (4.3 and 6.2 p = 0.0078) and were more likely to receive transfusion (73% and 56%, p= 0.071). Hemolysis at birth was reported in 59% (n=22) of newborns with available data with 13 neonates (38%) requiring transfusion support . Use of steroids had no effect on presence of hemolysis in the newborn.Conclusions: We present the largest cohort of p-AIHA described in the literature. Our study reports that p-AIHA is uncommon in primigravidas and typically presents later in pregnancy. Presentation in first or second trimester in pregnancy and lower Hb nadir were significantly associated with adverse pregnancy outcomes. Steroids and blood transfusions were needed in most patients, and hemolysis persisted on average for 6 weeks postpartum. There was a high frequency of Coombs negativity which was associated with shorter duration of postpartum hemolysis. Preterm labor and stillbirth were observed in 33.3% of pregnancies. The incidence of hemolysis in newborns from p-AIHA mothers is very high and is often clinically significant. Recurrence in subsequent pregnancy is common but has similar Hb nadir as non-recurrent cases. This study provides insights into the clinical course of pregnancy and neonatal outcomes in p-AIHA. Our findings may help guide management of this rare condition. A prospective study of patients with p-AIHA is needed to determine optimal therapy to reduce antepartum and neonatal complications. [Display omitted] DisclosuresMurakhovskaya: Alexion, Rigel, Bioverativ/Sanofi, Momenta, Annexion, Incyte: Research Funding; Bioverativ/Sanofi, Momenta, Apellis, Novartis: Consultancy; Cardiff Oncology, Trillium Therapeutics: Current holder of individual stocks in a privately-held company.

S3303 Outcomes of Gastrointestinal Bleeding During the COVID-19 Pandemic

Introduction: The novel circumstances during the pandemic have led to many challenges for clinicians and patients, including cancellation of procedures, policy regulations and the reluctance of patients to seek medical attention, potentially leading to adverse outcomes. Patients with gastrointestinal bleeding (GIB) require early resuscitation and possible intervention. The aim of this study was to investigate differences in the outcomes of hospitalized patients who encountered GIB during the initial peak of Coronavirus 2019 (COVID-19) pandemic in March 2020, compared to the year prior. Methods: In this retrospective cohort study, patients with GIB who presented to our institution during the first two weeks of March 2019 and 2020 were identified using ICD-10 codes for GIB. The diagnosis of GIB was confirmed based on assessment of hemoglobin (Hb), diagnostic imaging, endoscopy or clinical evidence of gross hemorrhage. Analysis was conducted with the Welch T-test and Pearson's chi-square test utilizing R 4.1.0. Results: We identified 89 patients with GIB in 2019 and 76 in 2020. Of the 2020 cohort, 88.2% tested positive for COVID-19. Compared with 2019, patients in 2020 were significantly older (years) (62.1 vs 68.3, P < 0.01), required longer hospital length of stay (days) (11.3 vs 20.9, P < 0.01), had higher rate of mortality (12.5% vs 36%, P < 0.01), were less likely to have history of cirrhosis (25.8% vs 6.6%, P < 0.01), presented with a higher Hb (mL/dL) (9.9 vs 11.9, P < 0.001), were less likely to undergo EGD (58.4% vs 13.2%, P < 0.001), or colonoscopy (21.6% vs 4 %, P < 0.01). There was no significant difference between baseline Hb or nadir Hb, P >0.05. The most common primary causes of death in 2019 were decompensated liver failure (27.3%), followed by septic shock (18%) and cardiogenic shock (18%), compared to 2020 deaths, which were COVID-19 respiratory failure (67.9%), hemorrhagic shock (11.1%) and cardiogenic shock (7%). Conclusion: Despite presenting with higher Hb on admission, patients during the COVID-19 pandemic had a higher rate of mortality. The most common cause of death was respiratory failure secondary to COVID-19. Our results also suggested patients with GIB were less likely to undergo endoscopic evaluation during the pandemic. Given the limitations of our study, it’s difficult to say whether this was due to strict COVID-19 isolation precautions, cardiopulmonary instability making endoscopy high risk, or clinical assessment suggesting GIB was not the primary cause of patient decline.Table 1.: Primary causes of death in year 2019 and 2020.

S2796 Warm Autoimmune Hemolytic Anemia Secondary to Acute Hepatitis B Virus Infection

Introduction: Autoimmune hemolytic anemia (AIHA) is a rare extrahepatic manifestation, typically associated with HIV, hepatitis C, E, and Epstein Barr virus (EBV) infections. Hepatitis B virus (HBV) induced AIHA is an unusual association, not previously described in the literature. We report the first case of HBV-induced warm-AIHA, successfully treated with corticosteroids and anti-viral therapy. Case Description/Methods: A 67-year-old man presented to our hospital with one month of myalgias, arthralgias, and fatigue. He had no known history of the lymphoproliferative disorder, autoimmune disease, immunodeficiency, malignancy, or alcohol abuse. He lived in the woods and reported previous tick exposure and recent unprotected sexual encounters with multiple intravenous drug users. His physical examination revealed mild scleral icterus. Laboratory workup was notable for hemoglobin (Hb) 12.5 gm/dL, reticulocyte count 4.1%, elevated aspartate aminotransferase 493 units/L, alanine aminotransferase 693 units/L, total bilirubin 5.3mg/dL with indirect bilirubinemia 2.4 mg/dL, lactate dehydrogenase 1,158 units/L, and undetectable haptoglobin. Immunohematologic studies showed a direct antiglobulin test positive for IgG and C3 with isolation of warm autoantibodies by elution, consistent with a diagnosis of warm AIHA. Workup to elucidate the cause of AIHA including ANA, anti-proteinase-3, myeloperoxidase antibodies, peripheral blood smear, malaria smear, northeast tick panel, serum protein electrophoresis, and immunofixation were unrevealing. HIV, hepatitis A, C, E, and EBV infections were ruled out. HBV serologies revealed positive HBs-antigen, anti-HBc IgM, and PCR quantification HBV DNA 824,000,000 IU/ml, consistent with acute HBV infection. A diagnosis of warm AIHA secondary to acute HBV infection was made. 1mg/kg/day of prednisone and Tenofovir 25 mg/day were started. During the hospitalization, his anemia worsened, reaching a Hb nadir of 5.2 gm/dl and requiring ten units of packed red blood cell transfusions. He eventually stabilized at day 18, followed by a sustained virological response, clinical and laboratory remission of AIHA. Discussion: This case highlights AIHA as an unusual manifestation of acute HBV infection. An association between AIHA and hepatic viruses, including HIV, HCV, and EBV, has been well recognized. Acute HBV infection induced AIHA has not been reported in the literature yet. Therefore, clinicians should consider HBV infection in any patient presenting with new-onset AIHA of unclear etiology.Figure 1.: The patient's jaundice on physical exam.

Anaemia in elderly patients at discharge from intensive care and hospital.

Anaemia is common in the elderly and is recognized as a risk factor for several adverse outcomes in older adults, including hospitalization, morbidity and mortality. The study aims were to examine the prevalence of anaemia in elderly patients at discharge from the intensive care unit (ICU) and hospital. Patient randomized under the INFORM trial and with an ICU admission were included. Two cohorts, Cohort 1 patients who were alive on discharge from ICU and Cohort 2 patients who were discharged alive from hospital to home. Prevalence of significant anaemia defined as haemoglobin levels, less than 100 g/l was measured at ICU and hospital discharge. Overall, 76·5% (683/893) of elderly admissions in Cohort 1 had a haemoglobin <100 g/l, and 44·1% (395/893) had a haemoglobin <90 g/l on ICU discharge. Nadir haemoglobin during ICU stay, length of stay in ICU and transfusion during ICU stay was associated with significant anaemia at ICU discharge. At hospital discharge, in Cohort 2, 54·8% (263/480) of elderly ICU admissions had Hb < 100 g/l, and 23·4% (112/480) had Hb < 90 g/l. Male gender, haemoglobin level at ICU discharge, and length of stay and nadir Hb between ICU and hospital discharge were associated with anaemia at hospital discharge. Significant anaemia is highly prevalent in elderly patients on discharge from ICU and to a lesser degree at hospital discharge.

327 Implementation of an antepartum anemia protocol: a prospective cohort study

In randomized trials, antepartum intravenous iron sucrose (IVFe) is effective at improving pre-delivery Hemoglobin (Hb). Yet, there is a gap between this knowledge and implementation into care. We aimed to determine if implementation of a standardized protocol for management of antepartum anemia in the real-world improves IVFe utilization, as well as clinical outcomes. We performed a prospective cohort study evaluating incorporation of an anemia protocol into care. Our protocol, developed with multidisciplinary stakeholders, included (1) serial 3rd trimester Hb assessment (2) oral iron supplementation for antepartum Hb 9.5-11g/dL and (3) IVFe use (300mg weekly/3 weeks) for persistent Hb<9.5g/dL. We compared a 6-months Pre-implementation (1/2018-6/2018) to 6-months Post-implementation (1/2019-6/2019). Women with an antepartum Hb <11.0g/dL were included in this analysis. Outcomes evaluated: IVFe utilization, number of IVFe doses, pre-delivery Hb, and blood transfusion. 1455 women were included (Pre=792;Post=663) without significant baseline differences. Antepartum Hb nadir was no different between groups (Pre:10.2[9.6-10.6] vs. Post:10.2[9.6-10.6], p=0.67; Table). IVFe was administered to 23.6% of women with antepartum Hb<9.5g/dL in the Pre-implementation group compared to 41.7% Post-implementation (OR 1.79 95%CI [1.17-2.75]). Of the patients who received IVFe, more women in the Post-implementation received at least 3 IVFe doses (Pre:23.7% vs. Post:47.3%, p=0.02). Pre-delivery Hb significantly increased from Pre- to Post-implementation (Pre:10.9[10.1-11.6] vs. Post:11.0[10.3-11.7] p=0.03). There was a non-significant difference in blood transfusion between groups (Pre:7.1% vs. Post:5.0%, p=0.10). Implementation of a standardized antepartum anemia protocol is associated with increased IVFe utilization and an improvement in pre-delivery hemoglobin. Implementation strategies are needed to increase protocol adherence with the goal of a clinically significant reduction in blood product administration and morbidity at delivery.

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

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. 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. 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.

Effect of Perioperative Blood Transfusion in Anemic Patients Undergoing Infrainguinal Bypass

Patients who present with lower extremity ischemia are frequently anemic, and the optimal transfusion threshold for this cohort has remained controversial. We sought to evaluate the effect of blood transfusion on major adverse cardiac events (MACE), including myocardial infarction, dysrhythmia, stroke, congestive heart failure, and 30-day mortality for these patients. All consecutive patients who had undergone infrainguinal bypass at our institution from 2011 to 2020 were included. The primary outcome was MACE, and blood transfusion was the primary exposure. Univariate and multivariable analyses were performed to assess the effects of patient and procedural variables, including red blood cell transfusion, stratified by hemoglobin (Hb) nadir (<7, 7-8, >8 g/dL). Of the 287 patients reviewed for analysis, 146 (50.9%) had required transfusion (mean, 1.6 ± 3 U). The patients who had received a transfusion had had a mean nadir Hb of 8.3 ± 1.0 g/dL compared with 10.1 ± 1.7 g/dL for those without transfusion. The overall incidence of MACE was 15.7% (45 of 287 patients). Univariate analysis demonstrated that MACE was associated with blood transfusion (P = .009), lower Hb nadir (P = .02), higher blood loss (P = .003), higher baseline creatinine (P = .02), previous coronary revascularization (P = .002), nonambulatory status (P = .03), American Society of Anesthesiologists classification 4 or 5 (P < .0001), and preoperative P2Y12 antagonist therapy (P = .049). Transfusion was independently associated with MACE for patients with a Hb nadir >8 (odds ratio [OR], 3.09; P = .006) but not for patients with a Hb nadir of 7 to 8 (OR, 0.818; P = .77). The effect in the Hb nadir <7 group was inconclusive (Fig). The only other variables independently associated with MACE were previous coronary revascularization (OR, 2.58; P = .01) and higher blood loss (OR, 1.05; P = .02). The hospital length of stay for patients with MACE was significantly longer than that for patients without MACE (14.8 vs 8.2 days; P < .001). For patients undergoing infrainguinal bypass, receiving a transfusion with a Hb nadir >8 was associated with a threefold increase in MACE, with a length of stay twice as long. For patients with a Hb of 7 to 8, transfusion did not increase or reduce the incidence of MACE. These findings suggest no benefit of blood transfusions for patients with a Hb nadir >7 and harm for those with a Hb nadir >8.