A comparison of conservative and aggressive transfusion regimens in the perioperative management of sickle cell disease. The Preoperative Transfusion in Sickle Cell Disease Study Group

The role of preoperative transfusion in sickle cell disease, a systematic review and meta-analysis

This systematic review and meta-analysis aimed to provide guidance on preoperative blood transfusion strategies for patients with sickle cell disease (SCD). We included all randomized controlled and observational studies exploring the clinical outcomes of preoperative blood transfusion among patients with SCD compared to the conservative transfusion strategy until 14/09/2022. Sixteen studies involving 3486 participants were analysed. The findings revealed a significantly higher bleeding rate in patients who received preoperative transfusion than those who followed a conservative strategy (RR = 4.32, 95% CI 1.75-10.68, P = 0.002, I2 = 0%). However, the two strategies had no significant differences in other clinical outcomes, such as acute chest syndrome, painful crisis, fever, neurological complications, thrombosis, ICU admission, and mortality. It is important to note that all the included studies had a moderate risk of bias. Preoperative transfusion in SCD was associated with a higher bleeding risk but a similar risk in other outcomes compared to conservative strategies. Notably, the increased bleeding risk observed seldom had clinical significance. We recommend individualizing management strategies, considering the overall positive impact of transfusions in reducing complications. Further high-quality studies are needed to refine recommendations.

Society for Maternal-Fetal Medicine Consult Series #68: Sickle cell disease in pregnancy

Pregnant individuals with sickle cell disease have an increased risk of maternal and perinatal morbidity and mortality. However, prepregnancy counseling and multidisciplinary care can lead to favorable maternal and neonatal outcomes. In this consult series, we summarize what is known about sickle cell disease and provide guidance for sickle cell disease management during pregnancy. The following are Society for Maternal-Fetal Medicine recommendations.

Microsurgery in the Sickle Cell Trait Population: Can it Be Safely and Successfully Performed?

Free-tissue transfer reconstruction in patients with sickle cell anemia risks failure due to polymerization of sickle hemoglobin within the flap microcirculation. However, outcomes vary, as the amount of polymerization is dependent on factors such as disease phenotype/diagnosis, degree of hypoxia, and intracellular dehydration. Most of the literature focuses on patients with sickle cell disease, which produces higher concentrations of sickle hemoglobin and, therefore, is a contraindication to microvascular reconstruction. Fewer reports describe microsurgery in patients with sickle cell trait (SCT) who carry the heterozygous phenotype. Here, we present a case in which a patient with SCT underwent microsurgical breast reconstruction with deep inferior epigastric perforator free-tissue transfer. The 52-year-old woman had previously experienced a failed alloplastic-based reconstruction after radiation therapy for breast cancer. In our case, clinical and Doppler examinations demonstrated that arterial and venous anastomoses had remained patent; so the patient was discharged on postoperative day 4. Blistering developed on postoperative day 8, and by day 15 there was partial necrosis of the inferior-lateral aspect of the deep inferior epigastric perforator flap. Debridement and closure resolved the issue, and at 5 months postprocedure, the flap remained well-perfused and well-incorporated. This case, presented here with patient consent, reports a successful outcome of microsurgical reconstruction in a patient with SCT. It expands the limited evidence to support the safety and feasibility of autologous surgical interventions for patients with the heterozygous phenotype of sickle cell anemia.

Global burden of transfusion in sickle cell disease

Sickle cell disease (SCD) is the most common hereditary hemoglobinopathy. The underlying pathophysiology of the red blood cell (RBC) leads to pan-systemic complications which manifest at an early age. While curative and disease-modifying treatments exist for SCD, a key intervention in the management and treatment of SCD is RBC transfusion, which can alleviate or prevent many complications. SCD patients often require chronic RBC transfusion therapy which can result in complications, such as iron overload, alloimmunization and infection. In low- and middle-income countries (LMICs), SCD patients lack appropriate access to healthcare such as newborn screening, health education, prophylaxis for infection, and treatments to reduce both mortality and SCD-related adverse effects. Poor access to RBCs for transfusion, coupled with donated blood not meeting safety standards set by the World Health Organization, presents a significant barrier for patients requiring chronic transfusions in LMICs. Unmet needs associated with blood collection, blood component processing and recipient matching all pose a serious problem in many LMICs, although this varies depending on geographic location, political organizations and economy. This review aims to provide an overview of the global burden of SCD, focusing on the availability of current treatments and the burden of chronic RBC transfusions in patients with SCD.

A case report and review of literature on the role of automated red cell exchange in managing sickle cell crisis in India

Red cell exchanges (RCE) help in the treatment of complications of sickle cell anemia (SCA) by reducing the viscosity of blood and improving the oxygen-carrying capacity. We present a case of sickle cell crisis (SCC) managed with automated RCE and also reviewed the literature to assess the utilization and clinical efficiency of this therapy in India. A 19-year-old gentleman diagnosed with SCA presented with acute chest syndrome. Hemoglobin (Hb) was 8.8 g%, hematocrit (HCT) was 24%, and HbS was 90%. As there was worsening of symptoms with conventional management, the patient underwent two procedures of automated RCE. The clinical condition of the patient was improved, HbS was reduced to 16% and HCT was remained at 21% postprocedure. Articles on automated RCE in SCA conducted in India were reviewed and four articles were analyzed based on the search strategy. All the included articles concluded automated RCE as an effective procedure for complications of SCA. Common indication in India was SCA patients undergoing surgery as a prophylactic measure. Automated RCEs are promising as an acute treatment for indicated sickle cell complications. This therapy is underutilized in the Indian scenario, especially in patients with SCC.

Reassessing the Need for Preoperative Transfusions in Sickle Cell Disease Patients With an Elevated Baseline Hemoglobin-A Retrospective Study

BACKGROUND

Current guidelines recommend a preoperative hemoglobin of 10.0 g/dL in patients with sickle cell disease [SCD], however, this threshold continues to be an area of controversy. Previous studies demonstrating the benefits of preoperative transfusions have largely not captured patients with elevated baseline hemoglobin, in part due to low hydroxyurea uptake and exclusion of nonhemoglobin SS SCD.

MATERIALS AND METHODS

We conducted a retrospective chart review of patients with SCD <18 years of age undergoing low and medium-risk procedures at 2 academic medical centers in Canada between 2007 and 2017. The primary objective was to study the association of preoperative transfusion on postoperative complications in patients with SCD with baseline hemoglobin between 9.0 and 10.0 g/dL. Multivariable logistic regression was used to estimate the adjusted effect of preoperative transfusion on the risk of developing postoperative complications.

RESULTS

In all, 159 procedures in patients with hemoglobin <9.0 g/dL [Hb <9.0 ] and 173 procedures in patients with hemoglobin between 9.0 and 10.0 g/dL [Hb 9.0-10.0 ] were analyzed. In the absence of preoperative transfusion, Hb 9.0-10.0 patients had lower overall complications [23% vs. 34%] compared with Hb <9.0 patients [OR 0.29, 95% CI 0.12-0.72, P =0.008]. In total, 75% of Hb <9.0 and 21% of Hb 9.0-10.0 patients received a preoperative simple transfusion. Transfusion was associated with increased risk of postoperative complications in Hb 9.0-10.0 [OR 3.02, 95% CI 1.26-7.23, P =0.013], but not Hb <9.0 patients [OR 0.64, 95% CI 0.28-1.45, P =0.30].

CONCLUSIONS

Simple transfusion may not be warranted in Hb 9.0-10.0 patients undergoing low-risk procedures. Prospective studies validating these findings are needed.

Current Evidence and Rationale to Guide Perioperative Management, Including Transfusion Decisions, in Patients With Sickle Cell Disease

Sickle cell disease (SCD) is a collection of inherited hemoglobin disorders that results in chronic hemolytic anemia, vaso-occlusion, pain, and end organ damage. Surgery in the SCD population requires careful planning, as perioperative stressors can lead to increased sickling and risk of inducing or further exacerbating vaso-occlusive episodes (VOEs). Additionally, the underlying hypercoagulability and immunocompromised state due to SCD places patients at increased risk of both venous thromboembolism and infection. Judicious fluid administration, temperature regulation, thorough preoperative and postoperative analgesic planning, and preoperative transfusion are all crucial components of decreasing risks of surgery in patients with SCD.

Preoperative Transfusion in Sickle Cell Disease Children Undergoing Adenotonsillectomy

Objective

To perform a systematic review and meta-analysis comparing two pre-operative transfusion regimens (conservative versus aggressive) in children with sickle cell disease(SCD) undergoing adenotonsillectomy in terms of post-operative complications, complications related to SCD and transfusion related complications.

Data Sources and Review Methods

A literature review was performed through PubMed, EMBASE, Cochrane, and Ovid databases using the following phrases: (Adenotonsillectomy OR Tonsillectomy) AND (Sickle Cell Disease OR Sickle Cell Trait). Using predetermined inclusion and exclusion criteria, seven articles were selected for systemic review and two control trials were included in meta-analysis.

Results

Out of a total of 3,146 results, seven articles were selected for review and two controlled trials were included in the meta-analysis. There was no statistically significant difference in the rate of primary and secondary hemorrhage between the aggressive and conservative transfusion regimens (RR = 3.1, CI = 0.84-11.4, p-value = 0.089). The rate of sickle cell disease related complications including vaso-occlusive crisis and acute chest syndrome was also not statistically significant between the two transfusion groups (RR = 1.4, CI = 0.7-2.8, p-value = 0.339). Even though, the transfusion related complications did not reach statistical significance, there was a higher complication rate in the group receiving aggressive blood transfusion.

Conclusion

In SCD children undergoing adenotonsillectomy, an aggressive transfusion regimen that focuses on reducing the Hemoglobin S ratio to below 30% has not been shown to be more effective in reducing post-operative complications when compared to a conservative transfusion regimen. Therefore, it is reasonable to utilize a conservative transfusion regimen, thereby reducing the transfusion-associated risks.

Management of Older Adults with Sickle Cell Disease: Considerations for Current and Emerging Therapies

People with sickle cell disease (SCD) are living longer than ever before, with the median survival increasing from age 14 years in 1973, beyond age 40 years in the 1990s, and as high as 61 years in recent cohorts from academic centers. Improvements in survival have been attributed to initiatives, such as newborn screening, penicillin prophylaxis, vaccination against encapsulated organisms, better detection and treatment of splenic sequestration, and improved transfusion support. There are an estimated 100,000 people living with SCD in the United States and millions of people with SCD globally. Given that the number of older adults with SCD will likely continue to increase as survival improves, better evidence on how to manage this population is needed. When managing older adults with SCD (defined herein as age ≥ 40 years), healthcare providers should consider the potential pitfalls of extrapolating evidence from existing studies on current and emerging therapies that have typically been conducted with participants at mean ages far below 40 years. Older adults with SCD have historically had little to no representation in clinical trials; therefore, more guidance is needed on how to use current and emerging therapies in this population. This article summarizes the available evidence for managing older adults with SCD and discusses potential challenges to using approved and emerging drugs in this population.

An Overview of Solid Organ Transplantation in Patients With Sickle Cell Disease

Sickle cell disease is a common genetic disorder affecting >300 000 people across the world. The vast majority of patients cared for in high-resource settings live well into adulthood, but many develop a high burden of disease complications. Good standard of care including disease-modifying agents and transfusion programs limits the number of patients who develop end-stage organ disease, but for those that do, the prognosis can be very poor. Solid organ transplantation is a well-established mode of treatment for patients with sickle cell disease and kidney or liver failure, but appropriate patient selection and perioperative management are important for achieving good outcomes. Hematopoietic stem cell transplantation and gene therapy may offer novel treatment options for adult patients with chronic organ damage in the future, but these are not yet widely available. For now, good, holistic care and early intervention of end-organ complications can minimize the number of patients requiring solid organ transplantation later in life.

How does sickle cell disease affect the peri-operative outcome in patients undergoing total knee arthroplasty? A large-scale, National Inpatient Sample-based study

INTRODUCTION

In view of the vaso-occlusive pathophysiology affecting osseous micro-circulation, sickle cell disease (SCD) is well known to present with diverse skeletal and arthritic manifestations. With prolonged life-expectancy over the past decades, there has been a progressive increase in the proportion of SCD patients requiring joint reconstructions. Owing to the paucity of evidence in the literature, the post-operative complication rates and outcome in these patients following total knee arthroplasty (TKA) are still largely unknown.

METHODS

Based on the National Inpatient Sample (NIS) database (using ICD-10 CMP code), patients who underwent TKA between 2016 and 2019 were identified. The cohort were classified into two groups: A-those with SCD; and B-those without. The data on patients' demographics, co-morbidities, details regarding hospital stay including expenditure incurred, and complications were analyzed and compared.

RESULTS

Overall, 558,361 patients underwent unilateral, primary TKA; among whom, 493 (0.1%) were known cases of SCD (group A). Group A included a significantly greater proportion of younger (60.14 ± 10.87 vs 66.72 ± 9.50 years; p < 0.001), male (77.3 vs 61.5%; p < 0.001); and African-American (88.2 vs 8.3%B; p < 0.001) patients, in comparison with group B. Group A patients were also at a significantly higher risk for longer duration of peri-operative hospital stay (p < 0.001), greater health-care costs incurred (p < 0.001), and greater need for alternative step-down health-care facilities (p < 0.001) following discharge. Among the SCD patients, 24.7%, 20.9% and 24.9% developed acute chest syndrome, pain crisis and splenic sequestration crisis, respectively during the peri-operative period. Group A patients had a statistically greater incidence of acute renal failure (ARF; p = 0.014), need for blood transfusion (p < 0.001) and deep vein thrombosis (DVT; p = 0.03) during the early admission period.

CONCLUSION

The presence of SCD substantially lengthens the duration of hospital stay and enhances health care-associated expenditure in patients undergoing TKA. SCD patients are at significantly higher risk for systemic complications including acute chest syndrome, pain crisis, splenic sequestration crisis, acute renal failure, higher need for blood transfusions and deep venous thrombosis during the initial peri-operative period following TKA.

The Cardiopulmonary Complications of Sickle Cell Disease

Sickle cell disease (SCD) is a genetic hemoglobinopathy associated with extensive morbidity and early mortality. While there have been recent improvements in available disease-modifying therapies for SCD, cardiopulmonary complications remain a major risk factor for death in this population. We provide an overview of current knowledge regarding several of the major acute and chronic cardiopulmonary complications in SCD, including: acute chest syndrome, airway disease, lung function abnormalities, nocturnal hypoxemia and sleep disordered breathing, pulmonary vascular disease, and sickle cell cardiomyopathy.

Considerations in the Sickle Cell Patient Undergoing Hip Reconstructive Surgery

Sickle cell disease (SCD) is a hemoglobinopathy that commonly has musculoskeletal effects including osteonecrosis of major joints (most often the hip) and medullary infarcts with resultant pain, functional limitations, and decreased quality of life. Patients with SCD may require surgical intervention, including total hip arthroplasty, frequently at a young age. The underlying pathologic process of SCD creates unique medical and surgical challenges that place these patients at increased risk of complications. This necessitates a multidisciplinary approach for providing surgical care to patients with SCD.

Clinical outcome of pre-operative blood transfusion for sickle cell disease patients in post-operative complications

BACKGROUND

Preoperative blood transfusion for patients with sickle cell disease is a debatable topic and it can be lifesaving. Sickle cell disease patients are at high risk for vaso-occlusive crisis due to the large concentration of sickle hemoglobin (HgbS) in their blood. Despite the current extensive research into this disease, there is still no consensus over whether blood transfusion is a preferable preoperative modality among patients undergoing elective surgical procedures.

METHOD

A retrospective observational study, which enrolled 204 patients with Sickle cell disease who underwent surgery at King Fahad Hospital of the University (KFHU) over the last five years. The primary objective was to determine whether there is evidence that preoperative blood transfusion for SCD patients undergoing surgical procedures will reduce postoperative complications related to SCD.

RESULTS

A total of 204 patients were included, of which 30% had preoperative blood transfusion. Majority of patient 44% had undergone cholecystectomy. On multivariate logistic regression analysis, patients who did not undergo blood transfusion had significantly higher risk to develop post-operative SCD complications (OR=3.07, P value= 0.002). In addition, they had significantly prolonged hospitalization (OR= 2.22, P value= 0.08). In contrast, patients who received blood transfusion had lower risk for developing post-operative SCD related complications (OR=1.87, P value= 0.29), and decrease in the duration of hospitalization by (OR=0.49, P value= 0.045).

CONCLUSION

Our study showed that patients who had not undergo preoperative blood transfusion had higher risk to develop postoperative complications and prolonged hospital stay compared to those who underwent blood transfusion.

Preoperative Transfusion and Surgical Outcomes for Children with Sickle Cell Disease

BACKGROUND

Current guidelines recommending preoperative transfusion to a hemoglobin level of 9 to 10 g/dL for patients with sickle cell disease (SCD) are based on imperfect evidence. The benefit of preoperative transfusion in children specifically is not known. This study aimed to evaluate whether preoperative RBC transfusion is associated with different rates of sickle cell crisis and surgical complications, compared with no preoperative transfusion, among children with SCD undergoing common abdominal operations.

STUDY DESIGN

The NSQIP-Pediatrics database (2013 to 2019) was queried. Patients who underwent cholecystectomy, splenectomy, or appendectomy with a preoperative Hct level of less than 30% were included. The primary outcome was 30-day readmission for sickle cell crisis. Secondary outcomes were 30-day surgical complications and hospital length of stay. Propensity score matching methods were used to obtain two statistically similar cohorts of patients comprised of those who were preoperatively transfused and those who were not.

RESULTS

Among 357 SCD patients, 200 (56%) received preoperative transfusion. In the matched cohort of 278 patients (139 per group), there was no statistically significant difference in 30-day readmission for sickle cell crisis in the transfused and non-transfused groups (5.8% vs 7.2%, p = 0.80). The rate of 30-day surgical complications did not differ between matched groups (10.8% vs 9.4%, p = 0.84). Subgroups defined by presenting Hct levels of 27.3% or greater or less than 27.3%, American Society of Anesthesiologists classification, wound class, and index operation were not associated with an altered risk of sickle cell crisis or surgical complications after preoperative transfusion compared with no transfusion.

CONCLUSIONS

Preoperative transfusion for children with SCD undergoing semi-elective abdominal operations was not associated with improved outcomes. Prospective investigation is warranted to strengthen guidelines and minimize unnecessary perioperative transfusions in this population.

Simple open-heart surgery protocol for sickle-cell disease patients: a retrospective cohort study comparing patients undergoing mitral valve surgery

OBJECTIVES

Sickle-cell disease (SCD) patients are considered to be at high risk from open-heart surgery. This study assessed the role of a simple sickling-prevention protocol.

METHODS

Perioperative non-specific and SCD-specific morbidity and 30-day mortality are investigated in a retrospective cohort study on patients undergoing isolated mitral valve surgery. Patients with and without SCD were compared. In the SCD cohort, a bundle of interventions was applied to limit the risk of sickling: 'on-demand' transfusions to keep haemoglobin levels of around 7-8 g/dl, cardiopulmonary bypass (CPB) with higher blood flow and perfusion temperature, close monitoring of acid-base balance and oxygenation.

RESULTS

Twenty patients with and 40 patients without SCD were included. At baseline, only preoperative haemoglobin levels differed between cohorts (8.1 vs 11.8 g/dl, P < 0.001). Solely SCD patients received preoperative transfusions (45.0%). Intraoperative transfusions were significantly larger in SCD patients during CPB (priming: 300 vs 200 ml; entire length: 600 vs 300 ml and 20 vs 10 ml/kg). SCD patients had higher perfusion temperatures during CPB (34.7 vs 33.0°C, P = 0.01) with consequently higher pharyngeal temperature, both during cooling (34.1 vs 32.3°C, P = 0.02) and rewarming (36.5 vs 36.2°C, P = 0.02). No mortality occurred, and non-SCD-specific complications were comparable between groups, but one SCD patient suffered from perioperative cerebrovascular accident with seizures, and another had evident haemolysis.

CONCLUSIONS

SCD patients may undergo open-heart surgery for mitral valve procedures with an acceptable risk profile. Simple but thoughtful perioperative management, embracing 'on-demand' transfusions and less-aggressive CPB cooling is feasible and probably efficacious.

Risks and Benefits of Prophylactic Transfusion before Cholecystectomy in Sickle Cell Disease

Preoperative transfusion (PT) reduces acute postoperative vaso-occlusive events (VOE) in sickle cell disease (SCD), but exposes patients to alloimmunization, encouraging a recent trend towards transfusion sparing. The aim of this study was to investigate the benefit–risk ratio of PT before cholecystectomy on the occurrence of postoperative VOE. Adult SCD patients who underwent cholecystectomy between 2008 and 2019 in our center were included. Patients’ characteristics, collected retrospectively, were compared according to PT. A total of 79 patients were included, 66% of whom received PT. Gallbladder histopathology found chronic cholecystitis (97%) and gallstones (66%). Transfused patients underwent more urgent surgeries and had experienced more painful vaso-occlusive crises (VOC) in the month before surgery (p = 0.05). Four (8.5%) post-transfusion alloimmunizations occurred, and two of them caused a delayed hemolytic transfusion reaction (DHTR) (4.3%). The occurrence of postoperative VOE was similar between the groups (19.2% vs. 29.6%, p = 0.45). Though not statistically significant, a history of hospitalized VOC within 6 months prior to surgery seemed to be associated to postoperative VOE among non-transfused patients (75% vs. 31.6%, p = 0.10). PT before cholecystectomy exposes to risks of alloimmunization and DHTR that could be avoided in some patients. Recent VOCs appear to be associated with a higher risk of postoperative VOE and prompt the preemptive transfusion of these patients.

Axillary intra-aortic balloon pump, biventricular assist device implantation and subsequent orthotopic heart transplantation in a patient with sickle cell trait

A 38-year-old male with sickle cell trait and acute refractory heart failure received an axillary intra-aortic balloon pump and short-term biventricular assist device. He underwent orthotopic heart transplantation 45 days later, which was complicated by major bleeding necessitating significant intra-operative transfusion. Support with veno-arterial extracorporeal membrane oxygenation was provided and successfully weaned five days later. He made a full recovery and remains alive and well 34 months after discharge. We hypothesize that the protective peri-operative measures undertaken, including normothermia during surgery and post-operative haemodynamic stability due to the use of mechanical circulatory support, conveyed a degree of protection against complications associated with sickle cell dysfunction and contributed to the successful outcome.

First Experience in Living Liver Donation From Donors With Sickle Cell Trait

Living donor liver transplantation is the main source of organs in the Middle East. Therefore, well balanced criteria are needed to avoid unnecessary exclusion of potential donors, while prioritizing donor safety. We face a high incidence of sickle cell trait (SCT; and disease). Therefore, there is vast experience in general and cardiac surgeries in SCT carriers at our center. After studying their management in detail, we considered accepting SCT carriers as living liver donors, on an exceptional basis. This the first single-center case series of living donor liver transplantation with SCT.

Acute chest syndrome of sickle cell disease: genetics, risk factors, prognosis and management

IntroductionSickle cell disease, one of the world's most prevalent Mendelian disorders, is a chronic hemolytic anemia punctuated by acute vasoocclusive events. Both hemolysis and vasoocclusion lead to irreversible organ damage and failure. Among the many sub-phenotypes of sickle cell disease is the acute chest syndrome (ACS) characterized by combinations of chest pain, cough, dyspnea, fever, abnormal lung exam, leukocytosis, hypoxia, and new radiographic opacities. ACS is a major cause of morbidity and mortality.Area coveredWe briefly review the diagnosis, epidemiology, etiology, and current treatments for ACS and focus on understanding and estimating the risks for developing this complication, how prognosis and outcomes might be improved and the genetic elements that might impact the risk of ACS.Expert opinionThe clinical heterogeneity of ACS has hindered our understanding of risk stratification. Lacking controlled clinical trials most treatment is based on expert opinion. Fetal hemoglobin levels and coexistent α thalassemia affect the incidence of ACS; other genetic associations are tenuous. Transfusions, whose use not innocuous, should be targeted to the severity and likelihood of ACS progression. Stable, non-hypoxic patients with favorable hematologic and radiographic findings usually do not need transfusion; severe progressive ACS is best managed with exchange transfusion.

Fertility preservation for pediatric patients with hemoglobinopathies: Multidisciplinary counseling needed to optimize outcomes

Hemoglobinopathies are autosomal recessive disorders that occur when genetic mutations negatively impact the function of hemoglobin. Common hemoglobinopathies that are clinically significant include sickle cell disease, alpha thalassemia, and beta thalassemia. Advancements in disease-modifying and curative treatments for the common hemoglobinopathies over the past thirty years have led to improvements in patient quality of life and longevity for those who are affected. However, the diseases, their treatments and cures pose infertility risks, making fertility preservation counseling and treatment an important part of the contemporary comprehensive patient care. Sickle cell disease negatively impacts both male and female infertility, primarily by testicular failure and decreased ovarian reserve, respectively. Fertility in both males and females with beta thalassemia major are negatively impacted by iron deposition due to chronic blood transfusions. Hematopoietic stem cell transplant (HSCT) is currently the only curative treatment for SCD and transfusion dependent beta thalassemia. Many of the conditioning regimens for HSCT contain chemotherapeutic agents with known gonadotoxicity and whole-body radiation. Although most clinical studies on toxicity and impact of HSCT on long-term health do not evaluate fertility, gonadal failure is common. Male fertility preservation modalities that exist prior to gonadotoxic treatment include sperm banking for pubertal males and testicular cryopreservation for pre-pubertal boys. For female patients, fertility preservation options include oocyte cryopreservation and ovarian tissue cryopreservation. Oocyte cryopreservation requires controlled ovarian hyperstimulation (COH) with ten to fourteen days of intensive monitoring and medication administration. This is feasible once the patient has undergone menarche. Follicular growth is monitored via transvaginal or transabdominal ultrasound, and hormone levels are monitored through frequent blood work. Oocytes are then harvested via a minimally invasive approach under anesthesia. Complications of COH are more common in patients with hemoglobinopathies. Ovarian hyperstimulation syndrome creates a greater risk to patients with underlying vascular, pulmonary, and renal injury, as they may be less able to tolerate fluids shifts. Thus, it is critical to monitor patients undergoing COH closely with close collaboration between the hematology team and the reproductive endocrinology team. Counseling patients and families about future fertility must take into consideration the patient's disease, treatment history, and planned treatment, acknowledging current knowledge gaps.

Transfusion thresholds for guiding red blood cell transfusion

BACKGROUND

The optimal haemoglobin threshold for use of red blood cell (RBC) transfusions in anaemic patients remains an active field of research. Blood is a scarce resource, and in some countries, transfusions are less safe than in others because of inadequate testing for viral pathogens. If a liberal transfusion policy does not improve clinical outcomes, or if it is equivalent, then adopting a more restrictive approach could be recognised as the standard of care.  OBJECTIVES: The aim of this review update was to compare 30-day mortality and other clinical outcomes for participants randomised to restrictive versus liberal red blood cell (RBC) transfusion thresholds (triggers) for all clinical conditions. The restrictive transfusion threshold uses a lower haemoglobin concentration as a threshold for transfusion (most commonly, 7.0 g/dL to 8.0 g/dL), and the liberal transfusion threshold uses a higher haemoglobin concentration as a threshold for transfusion (most commonly, 9.0 g/dL to 10.0 g/dL).

SEARCH METHODS

We identified trials through updated searches: CENTRAL (2020, Issue 11), MEDLINE (1946 to November 2020), Embase (1974 to November 2020), Transfusion Evidence Library (1950 to November 2020), Web of Science Conference Proceedings Citation Index (1990 to November 2020), and trial registries (November 2020). We  checked the reference lists of other published reviews and relevant papers to identify additional trials. We were aware of one trial identified in earlier searching that was in the process of being published (in February 2021), and we were able to include it before this review was finalised.

SELECTION CRITERIA

We included randomised trials of surgical or medical participants that recruited adults or children, or both. We excluded studies that focused on neonates. Eligible trials assigned intervention groups on the basis of different transfusion schedules or thresholds or 'triggers'. These thresholds would be defined by a haemoglobin (Hb) or haematocrit (Hct) concentration below which an RBC transfusion would be administered; the haemoglobin concentration remains the most commonly applied marker of the need for RBC transfusion in clinical practice. We included trials in which investigators had allocated participants to higher thresholds or more liberal transfusion strategies compared to more restrictive ones, which might include no transfusion. As in previous versions of this review, we did not exclude unregistered trials published after 2010 (as per the policy of the Cochrane Injuries Group, 2015), however, we did conduct analyses to consider the differential impact of results of trials for which prospective registration could not be confirmed.   DATA COLLECTION AND ANALYSIS: We identified trials for inclusion and extracted data using Cochrane methods. We pooled risk ratios of clinical outcomes across trials using a random-effects model. Two review authors independently extracted data and assessed risk of bias. We conducted predefined analyses by clinical subgroups. We defined participants randomly allocated to the lower transfusion threshold as being in the 'restrictive transfusion' group and those randomly allocated to the higher transfusion threshold as being in the 'liberal transfusion' group.

MAIN RESULTS

A total of 48 trials, involving data from 21,433 participants (at baseline), across a range of clinical contexts (e.g. orthopaedic, cardiac, or vascular surgery; critical care; acute blood loss (including gastrointestinal bleeding); acute coronary syndrome; cancer; leukaemia; haematological malignancies), met the eligibility criteria. The haemoglobin concentration used to define the restrictive transfusion group in most trials (36) was between 7.0 g/dL and 8.0 g/dL.  Most trials included only adults; three trials focused on children. The included studies were generally at low risk of bias for key domains including allocation concealment and incomplete outcome data. Restrictive transfusion strategies reduced the risk of receiving at least one RBC transfusion by 41% across a broad range of clinical contexts (risk ratio (RR) 0.59, 95% confidence interval (CI) 0.53 to 0.66; 42 studies, 20,057 participants; high-quality evidence), with a large amount of heterogeneity between trials (I² = 96%). Overall, restrictive transfusion strategies did not increase or decrease the risk of 30-day mortality compared with liberal transfusion strategies (RR 0.99, 95% CI 0.86 to 1.15; 31 studies, 16,729 participants; I² = 30%; moderate-quality evidence) or any of the other outcomes assessed (i.e. cardiac events (low-quality evidence), myocardial infarction, stroke, thromboembolism (all high-quality evidence)). High-quality evidence shows that the liberal transfusion threshold did not affect the risk of infection (pneumonia, wound infection, or bacteraemia). Transfusion-specific reactions are uncommon and were inconsistently reported within trials. We noted less certainty in the strength of evidence to support the safety of restrictive transfusion thresholds for the following predefined clinical subgroups: myocardial infarction, vascular surgery, haematological malignancies, and chronic bone-marrow disorders.

AUTHORS' CONCLUSIONS

Transfusion at a restrictive haemoglobin concentration decreased the proportion of people exposed to RBC transfusion by 41% across a broad range of clinical contexts. Across all trials, no evidence suggests that a restrictive transfusion strategy impacted 30-day mortality, mortality at other time points, or morbidity (i.e. cardiac events, myocardial infarction, stroke, pneumonia, thromboembolism, infection) compared with a liberal transfusion strategy. Despite including 17 more randomised trials (and 8846 participants), data remain insufficient to inform the safety of transfusion policies in important and selected clinical contexts, such as myocardial infarction, chronic cardiovascular disease, neurological injury or traumatic brain injury, stroke, thrombocytopenia, and cancer or haematological malignancies, including chronic bone marrow failure.  Further work is needed to improve our understanding of outcomes other than mortality. Most trials compared only two separate thresholds for haemoglobin concentration, which may not identify the actual optimal threshold for transfusion in a particular patient. Haemoglobin concentration may not be the most informative marker of the need for transfusion in individual patients with different degrees of physiological adaptation to anaemia. Notwithstanding these issues, overall findings provide good evidence that transfusions with allogeneic RBCs can be avoided in most patients with haemoglobin thresholds between the range of 7.0 g/dL and 8.0 g/dL. Some patient subgroups might benefit from RBCs to maintain higher haemoglobin concentrations; research efforts should focus on these clinical contexts.

Optimizing management of sickle cell disease in patients undergoing surgery

Individuals with sickle cell disease (SCD) are likely to be referred for surgery at some point in their lifetime due to a high incidence of musculoskeletal and intrabdominal complications such as avascular necrosis and gallbladder disease. Preoperative optimization is a multidisciplinary process that involves a hematologist with SCD expertise, an anesthesiologist, and the surgical team. The type and risk classification of the surgery, disease severity, medications, baseline hemoglobin, transfusion history, and history of prior surgical complications are often documented. Clinicians should consider perioperative risk assessment that includes determining the patient's functional status and cardiovascular risk and screening for obstructive sleep apnea. Many patients will require preoperative transfusion to reduce the risk of postoperative complications such as acute chest syndrome and vaso-occlusive pain crises. The hematologist should consider the patient's preoperative transfusion requirements and ensure that the surgical team has an appropriate plan for postoperative observation and management. This often includes follow-up laboratory studies, a postoperative pain management plan, and venous thromboembolism prophylaxis. The transfusion plan should be patient-specific and take into account the SCD genotype, baseline hemoglobin, disease severity, risk classification of the surgery, and history of prior surgical complications. In the intraoperative and postoperative period, dehydration, hypothermia, hypotension, hypoxia, and acidosis should be avoided, and incentive spirometry should be utilized to minimize complications such as acute chest syndrome. In this review we discuss preoperative, intraoperative, and postoperative strategies to optimize patients with SCD undergoing surgery.

Free Flap Reconstruction and Its Management in Sickle Cell Trait: Lessons Learned from a Case

Oral cancers are amongst the most common cancers in the Indian subcontinent; in India alone, an estimated 1.2 lakh new patients were diagnosed with it. Reconstruction with free flaps slowly gained popularity over time to become the standard for care for treating large head and neck defects. Flap selection is a complex process; more specifically, the preoperative conditions of patients, the extent of the disease, and the resources available are critical considerations to consider when selecting the best reconstructive technique. It is very well established that certain parts of India, especially the tribal area of Central and southern India, have high prevalence of sickle cell trait (SCT) and sickle cell disease compared to the rest of the country. The sickle cell trait poses a potential increase in morbidity in the perioperative care due to surgical stress. Unfortunately, there are no published articles on the management of a free flap in a case of SCT. Here, in this article, we investigate the issues encountered during the perioperative care in a patient who undergone oral cavity composite resection with free fibula reconstruction. SCT screening must be undertaken mainly to identify, mitigate, and manage the adverse events in the perioperative period. The screening test is very inexpensive and has good sensitivity to detect the heterozygous and homozygous disease. We would recommend screening of all the patients hailing from high-risk endemic areas. The free flap in a case of sickle cell trait is not a contraindication, but a surgeon must understand the nuances in the management of complications in such case. Screening for sickle cell trait followed by perioperative blood transfusions, anticoagulation seems beneficial in a patient undergoing free flaps with sickle cell trait.

Red cell transfusion and alloimmunization in sickle cell disease

Red cell transfusion remains a critical component of care for acute and chronic complications of sickle cell disease. Randomized clinical trials demonstrated the benefits of transfusion therapy for prevention of primary and secondary strokes and postoperative acute chest syndrome. Transfusion for splenic sequestration, acute chest syndrome, and acute stroke are guided by expert consensus recommendations. Despite overall improvements in blood inventory safety, adverse effects of transfusion are prevalent among patients with sickle cell disease and include alloimmunization, acute and delayed hemolytic transfusion reactions, and iron overload. Judicious use of red cell transfusions, optimization of red cell antigen matching, and the use of erythrocytapheresis and iron chelation can minimize adverse effects. Early recognition and management of hemolytic transfusion reactions can avert poor clinical outcomes. In this review, we discuss transfusion methods, indications, and complications in sickle cell disease with an emphasis on alloimmunization.

Risk factors for complications after abdominal surgery in children with sickle cell disease

BACKGROUND

Abdominal surgery in children with sickle cell disease (SCD) carries an increased risk of postoperative complications. Preoperative transfusions are frequently given to decrease the risk of vasoocclusive events. However, risk factors for postoperative complications are not well-defined in the pediatric population.

METHODS

Pediatric patients with SCD undergoing common abdominal operations were identified from the National Surgical Quality Improvement Program-Pediatric (NSQIP-P) database from 2012 to 2018. Outcomes of interest were the incidence rates of 1) any complication or readmission, and 2) serious SCD-related complications (stroke, new onset seizure, ventilator support >24 h postoperatively, or readmission with SCD crisis within 30 days of surgery). Patients were categorized by transfusion approach (transfusion within 48 h before surgery vs. no transfusion) and preoperative hematocrit (<21.0, 21.0-23.9, 24.0-26.9, 27.0-29.9, ≥30.0). Stratified bivariate analyses and multivariable logistic regression were used to identify independent risk factors for complications.

RESULTS

A total of 813 patients met inclusion criteria. There were 470 cholecystectomy, 251 splenectomy, 39 appendectomy, and 53 combination procedures; 13% of cases were urgent or emergent. Preoperative hematocrit levels were <21.0 in 3%, 21.0-23.9 in 10%, 24.0-26.9 in 17%, 27.0-29.9in 30%, and ≥30.0 in 41% of patients; 52% received perioperative transfusion. The 30-day incidences of any complication/readmission and SCD-related complications were 12% and 4%, respectively. On bivariate analyses, urgent/emergent case status was the only significant predictor of complications, carrying risk of 20% and 8% for overall and SCD-related complications, respectively; this finding persisted on multivariable logistic regression (OR 1.83, 95% CI 1.0.2-3.29, p = 0.04). Neither preoperative transfusion nor preoperative hematocrit level was associated with complication risk, although there was a trend toward higher SCD-related complications in patients with preoperative hematocrit <21.0 (p = 0.07).

CONCLUSION

In this large cohort of pediatric SCD patients undergoing abdominal surgery, there was no clear association between postoperative complications and the transfusion approach or the preoperative hematocrit level within the range above 21.0. Urgent/emergent surgical procedures carried a nearly two-fold higher complication risk compared to elective procedures. Future studies should prospectively evaluate preoperative transfusion approaches and compare immediate and delayed operative management to nonoperative management in this population.

LEVEL OF EVIDENCE

III Retrospective review.

Epidemiology, Pathogenesis, and Clinical Approach in Group 5 Pulmonary Hypertension

Pulmonary hypertension (PH) is recognized to be associated with a number of comorbid conditions. Based on these associations, PH is classified into 5 groups, considering common pathophysiologic drivers of disease, histopathologic features, clinical manifestations and course, and response to PH therapy. However, in some of these associated conditions, these characteristics are less well-understood. These include, among others, conditions commonly encountered in clinical practice such as sarcoidosis, sickle cell disease, myeloproliferative disorders, and chronic kidney disease/end stage renal disease. PH in these contexts presents a significant challenge to clinicians with respect to disease management. The most recent updated clinical classification schemata from the 6th World Symposium on PH classifies such entities in Group 5, highlighting the often unclear and/or multifactorial nature of PH. An in-depth review of the state of the science of Group 5 PH with respect to epidemiology, pathogenesis, and management is provided. Where applicable, future directions with respect to research needed to enhance understanding of the clinical course of these entities is also discussed.

Guideline on the peri-operative management of patients with sickle cell disease: Guideline from the Association of Anaesthetists

Sickle cell disease is a multisystem disease characterised by chronic haemolytic anaemia, painful vaso-occlusive crises and acute and chronic end-organ damage. It is one of the most common serious inherited single gene conditions worldwide and has a major impact on the health of affected individuals. Peri-operative complications are higher in patients with sickle cell disease compared with the general population and may be sickle or non-sickle-related. Complications may be reduced by meticulous peri-operative care and transfusion, but unnecessary transfusion should be avoided, particularly to reduce the risk of allo-immunisation. Planned surgery and anaesthesia for patients with sickle cell disease should ideally be undertaken in centres with experience in caring for these patients. In an emergency, advice should be sought from specialists with experience in sickle cell disease through the haemoglobinopathy network arrangements. Emerging data suggest that patients with sickle cell disease are at increased risk of COVID-19 infection but may have a relatively mild clinical course. Outcomes are determined by pre-existing comorbidities, as for the general population.

Postoperative acute multiple organ failure after hepatectomy in a Nigerian male with sickle cell trait: a case report

Background

Sickle cell disease (SCD) is a monogenic disease characterized by sickle hemoglobin (HbS). Patients homozygous for HbS experience symptoms resulting from sickled erythrocytes no later than adolescence. However, heterozygous HbS carriers, or those with the so-called sickle cell trait (SCT), may undergo surgery without their hemoglobinopathy being known.

Case presentation

A 53-year-old Nigerian male with hepatitis C infection underwent radiofrequency ablation therapy for multiple hepatocellular carcinomas (HCCs) 17 months prior. Follow-up computed tomography (CT) revealed a solitary tumor (3.2 cm) in the medial section of the cirrhotic liver. The Child–Pugh score was five, and the indocyanine green retention rate at 15 min was 17.4%. The nontumorous liver of the medial section accounted for 10% of the total liver volume according to CT volumetry. With the diagnosis of recurrent HCC, left medial sectionectomy was performed under intermittent blood flow occlusion by Pringle’s maneuver. Intraoperative ultrasonography confirmed that hepatic blood flow had been preserved after hepatectomy. However, laboratory tests on postoperative day (POD) 1 revealed severe liver damage: aspartate aminotransferase 9250 IU/L, alanine aminotransferase 6120 IU/L, total bilirubin 2.8 mg/dL, and prothrombin time% 20.9%. The patient’s renal and respiratory functions also deteriorated; therefore, continuous hemodiafiltration and plasma exchange were initiated under mechanical ventilation. Whole-body contrast-enhanced CT showed no apparent ischemia of the remnant liver, but diffuse cerebral infarction was detected. Despite intensive treatments, he died of multiple organ failure on POD 20. The pathological examination of the resected specimen revealed that the intrahepatic peripheral vessels were occluded by sickled erythrocytes. Additionally, chromatographic analysis of hemoglobin detected the presence of abnormal hemoglobin, although microscopic examination of the peripheral blood erythrocytes did not show morphological abnormalities. Based on these findings, we determined that he had SCT and developed vaso-occlusive crisis involving multiple organs just after hepatectomy.

Conclusion

SCD is a rare disease in eastern Asia, but its prevalence is increasing globally. Surgeons should pay increased attention to this disease, especially when performing hepatectomy under blood flow occlusion.

Nonsurgical Management of Acute Appendicitis in Sickle Cell Disease

A 9-year-old child with sickle cell disease (sickle beta zero thalassemia) was diagnosed to have acute appendicitis during a hospitalization for pain, acute chest syndrome, and exacerbation of asthma. Because of his high surgical risk, his appendicitis was treated nonsurgically, successfully deferring his appendectomy. He remains well after 1 year. This approach should be considered at least in other sickle cell patients with appendicitis, and perhaps other high-risk populations, if not all children with appendicitis.

Transfusion and Cellular Therapy in Pediatric Sickle Cell Disease

Red blood cell (RBC) transfusion is critical in managing acute and chronic complications of sickle cell disease. Alloimmunization and iron overload remain significant complications of transfusion therapy and are minimized with prophylactic Rh and K antigen RBC matching and iron chelation. Matched sibling donor hematopoietic stem cell transplant (HSCT) is a curative therapeutic option. Autologous hematopoietic stem cell (HSC)-based gene therapy has recently shown great promise, for which obtaining sufficient HSCs is essential for success. This article discusses RBC transfusion indications and complications, transfusion support during HSCT, and HSC mobilization and collection for autologous HSCT with gene therapy.

Understanding the demand for phenotyped red blood cell units and requests to perform molecular red blood cell typing for Australian patients

BACKGROUND

Australian Red Cross Lifeblood has seen a 50 % increase in demand for phenotyped red blood cell (RBC) units between 2016-2018 and a 30 % increase in demand in 2018 to perform molecular RBC typing on patient samples. Lifeblood conducted a survey to understand transfusion laboratory practices for requesting patient phenotyping and/or molecular RBC typing and for selecting phenotyped RBC units in various patient groups.

STUDY DESIGN AND METHODS

An electronic Qualtrics survey form was sent to 296 transfusion laboratories with questions designed to understand the practice of selecting phenotyped RBC units and reasons for requesting extended serology or molecular RBC typing.

RESULTS

49 (16.6 %) transfusion laboratories provided data. Reasons to request extended phenotyping and/or molecular RBC typing for patients included; chronic transfusion (n = 31 laboratories), sickle cell disease (n = 25), Thalassemia (n = 23), requirement for anti-CD38 or other MAB therapy (n = 23) or Myelodysplasia (n = 22). Forty-seven transfusion laboratories provided responses with reasons for requesting molecular RBC typing which included: predicting phenotype in patients with multiple antibodies (n = 31), prior to administering anti-CD38 or other MAB therapies (n = 29), for pregnancy related transfusions (n = 28) or for confirming the phenotype of recently transfused patients (n = 18).

CONCLUSION

Transfusion laboratory practices indicated that phenotyped RBC units were selected for patients requiring chronic transfusion support and/or undergoing MAB therapy. Requests for molecular RBC typing occurred for more complex patient requirements where serological investigations were not suitable or possible due to reagent restrictions.

Splenectomy in Jamaican children with sickle cell disease: Outcome of selective blood transfusion

We reviewed the post-operative morbidity and mortality of open splenectomy undertaken in conjunction with selective blood transfusion in Jamaican children with sickle cell disease. Data were collected on 150 splenectomies performed between November 1994 and October 2017. Selective blood transfusion involved raising haemoglobin levels to approximately 100 g/L in patients with admission haemoglobin ≥10 g/L below steady state. There was no mortality. Mean post-operative stay was 3.2 days with a median of three days. Total morbidity was 19/150 cases (12.7%), with acute chest syndrome accounting for 11/19 (57.9%). Among the non-transfused, acute chest syndrome occurred in 10/117 cases (8.5%), while among transfused, acute chest syndrome occurred in 1/33 cases (2.9%). We recommend this selective blood transfusion protocol for patients with sickle cell disease to surgeons who undertake splenectomies in settings where blood bank reserves are perennially low.

Total hip arthroplasty for sickle cell osteonecrosis: guidelines for perioperative management

The prognosis of sickle cell disease (SCD) has greatly improved in recent years, resulting in an increased number of patients reporting musculoskeletal complications such as osteonecrosis of the femoral head. Total hip arthroplasty (THA) can be utilized to alleviate the pain associated with this disease.

Although it is well known that hip arthroplasty for avascular necrosis (AVN) in SCD may represent a challenge for the surgeon, complications are frequent, and no guidelines exist to prevent these complications. Because patients with SCD will frequently undergo THA, we thought it necessary to fulfil the need for guidance recommendations based on experience, evidence and agreement from the literature.

For all these reasons this review proposes guidelines that provide clinicians with a document regarding management of patients with SCD in the period of time leading up to primary THA. The recommendations provide guidance that has been informed by the clinical expertise and experience of the authors and available literature.

Although this is not a systematic review since some papers may have been published in languages other than English, our study population consisted of 5,868 patients, including 2,126 patients with SCD operated on for THA by the senior author in the same hospital during 40 years and 3,742 patients reported in the literature.

Cite this article: EFORT Open Rev 2020;5:641-651. DOI: 10.1302/2058-5241.5.190073

Red blood cell exchange in sickle cell disease patient with multiple alloantibodies

There are several reports in medical literature about Red Cell Exchange (RCE) being routinely performed pre-operatively in sickle cell disease patients to provide immediate decrease in HbS concentration and prevent post-operative complications. We would like to present one such case of SCD who also had multiple allo-antibodies and had to undergo hemi-arthroplasty for avascular necrosis of head femur. Grouping and antibody screening was performed using column agglutination technique. 3-cell and 11- cell panel were used for antibody screening and identification, respectively. Automated RBC exchange was performed on apheresis machine Com. Tec using the standard PL1 kit (Fresenius Kabi, Germany). Multiple (anti-c, E) allo-antibodies were identified and successful pre-operative RCE was done with corresponding antigen-negative AHG compatible RBC units. Single RCE procedure reduced HbS concentration from 65% to 25%. The patient underwent uneventful hemi-arthroplasty and was discharged on post-operative day-7. Patient is on regular follow-up and continues to do well two months after the day of surgery. This is possibly the first case report from India, which illustrates successful automated RCE in a SCD patient with alloimmunization.

Beneficial effects of adenotonsillectomy in children with sickle cell disease

Tonsillectomy and adenoidectomy (T&A) is frequently performed in children with sickle cell disease (SCD). Our aim was to evaluate the impact of this surgery on overnight oxygenation and rates of complications in these patients.

Children with SCD who underwent T&A between 2008 and 2014 in two tertiary hospitals were retrospectively evaluated. Overnight oximetry and admission rates due to vaso-occlusive pain episodes (VOEs) and acute chest syndrome (ACS) in the year preceding and following the surgery were compared.

19 patients (10 males, 53%) with a median age of 6 years (range 3.5–8) were included. A significant increase of mean overnight arterial oxygen saturation measured by pulse oximetry (S_pO2) (from 93±3.6% to 95.3±2.8%, p=0.001), nadir S_pO2 (from 83.0±7.1% to 88±4.1%, p=0.004) and a reduction of 3% oxygen desaturation index (from a median value of 5.7 to 1.8, p=0.003) were shown. The mean annual rate of ACS decreased from 0.6±1.22 to 0.1±0.2 events per patient-year (p=0.003), while the mean cumulative rate of hospitalisations for all causes and the incidence of VOEs were not affected.

T&A improved nocturnal oxygenation and was also associated with a reduction in the incidence of ACS at 1-year follow-up after surgery.

In children with SCD, this retrospective analysis suggests that tonsillectomy and adenoidectomy may have a beneficial effect on nocturnal oxygenation level and the rate of ACS. This finding will need further confirmation in prospective and larger studies.https://bit.ly/3gL6gaU

Outcomes of a preoperative risk-based transfusion assignment protocol in sickle cell disease patients: a single-center retrospective study from Saudi Arabia

Many patients with sickle cell disease (SCD) need surgical management during their lifetime. The best approach for preoperative transfusion in SCD is still to be determined. In this single-center retrospective study, we included HBSS/HBS-Beta⁰-thalassemia patients younger than 16 years of age who underwent surgery between January 2008 and July 2019. Preoperative transfusion assignment (PTA) was based on SCD severity and surgical risk. Patients were assigned to no transfusion, simple transfusion, or exchange transfusion. A total of 284 patients were identified and 66 (23%) underwent 78 procedures. Mean age at the time of procedure was 8 (5-11) years, mean baseline hemoglobin was 8.5 (7.8-9.3) g/dl, and mean hemoglobin F was 18.4 ± 8.2%. SCD severity was low-risk in 57 (73%) and high-risk in 21 (27%) patients. Surgical risk was low-risk in 20 (25.6%) and medium-risk in 58 (74.4%) procedures. PTA was no transfusion in 17 (22%), simple transfusion in 40 (51%), and exchange transfusion in 21 (27%) procedures. Postoperative complications occurred in five (6.4%) of procedures only in the simple transfusion group (three acute chest syndrome, one hemolytic anemia, one pain crisis) undergoing medium-risk surgery. Preoperative risk-based transfusion assignment is feasible. Despite a high baseline hemoglobin level in the no transfusion group, none of the patients developed postoperative complications. It is possible that the high baseline hemoglobin F phenotype was protective and indicates the need to study the risk/benefit of interventions used in this phenotype.

Transfusion support in patients with sickle cell disease

Blood transfusions are an integral component of the management of acute and chronic complications of sickle cell disease. Red cells can be administered as a simple transfusion, part of a modified exchange procedure involving manual removal of autologous red cells and infusion of donor red cells, and part of an automated red cell exchange procedure using apheresis techniques. Individuals with sickle cell disease are at risk of multiple complications of blood transfusions, including transfusional hemosiderosis, auto- and alloimmunization to minor red cell and human leukocyte antigens, delayed hemolytic transfusion reactions, and hyper-hemolysis. In low- and middle-income countries in sub-Saharan Africa, where a directed donor system is prevalent and limited laboratory methods are in place to perform extended red cell phenotyping, leukodepletion of cellular products, and infectious disease screening, there are additional challenges to providing safe and adequate transfusion support for this patient population. We review current indications for acute and chronic transfusions in sickle cell disease that are derived primarily from randomized controlled trials and observational studies in children living in high-income countries. We will highlight populations with unique transfusion needs, such as pregnant women and children, as well as the role of the transfusion medicine consultative service for individuals with sickle cell disease planning to have curative hematopoietic stem cell transplantation or gene therapy. Finally, we will discuss risk factors for alloimmunization in individuals with sickle cell disease, emerging new strategies to prevent alloimmunization in this population, and critical gaps in the implementation of transfusion guidelines for sickle cell disease in high- and low-income countries.

Preoperative blood transfusions for sickle cell disease

BACKGROUND

Sickle cell disease (SCD) is one of the commonest severe monogenic disorders in the world, due to the inheritance of two abnormal haemoglobin (beta globin) genes. SCD can cause severe pain, significant end-organ damage, pulmonary complications, and premature death. Surgical interventions are more common in people with SCD, and occur at much younger ages than in the general population. Blood transfusions are frequently used prior to surgery and several regimens are used but there is no consensus over the best method or the necessity of transfusion in specific surgical cases. This is an update of a Cochrane Review.

OBJECTIVES

To determine whether there is evidence that preoperative blood transfusion in people with SCD undergoing elective or emergency surgery reduces mortality and perioperative or sickle cell-related serious adverse events. To compare the effectiveness of different transfusion regimens (aggressive or conservative) if preoperative transfusions are indicated in people with SCD.

SEARCH METHODS

We searched for relevant trials in the Cochrane Library, MEDLINE (from 1946), Embase (from 1974), the Transfusion Evidence Library (from 1980), and ongoing trial databases; all searches current to 28 January 2020 We searched the Cochrane Cystic Fibrosis and Genetic Disorders Group Trials Register: 19 September 2019.

SELECTION CRITERIA

All randomised controlled trials and quasi-randomised controlled trials comparing preoperative blood transfusion regimens to different regimens or no transfusion in people with SCD undergoing elective or emergency surgery. There was no restriction by outcomes examined, language or publication status.

DATA COLLECTION AND ANALYSIS

Two authors independently assessed trial eligibility and the risk of bias and extracted data.

MAIN RESULTS

Three trials with 990 participants were eligible for inclusion in the review. There were no ongoing trials identified. These trials were conducted between 1988 and 2011. The majority of people included had haemoglobin (Hb) SS SCD. The majority of surgical procedures were considered low or intermediate risk for developing sickle cell-related complications. Aggressive versus simple red blood cell transfusions One trial (551 participants) compared an aggressive transfusion regimen (decreasing sickle haemoglobin to less than 30%) to a simple transfusion regimen (increasing haemoglobin to 100 g/L). This trial re-randomised participants and therefore quantitative analysis was only possible on two subsets of data: participants undergoing cholecystectomy (230 participants); and participants undergoing tonsillectomy or adenoidectomy surgeries (107 participants). Data were not combined as we do not know if any participant received both surgeries. Overall, the quality of the evidence was very low across different outcomes according to GRADE methodology. This was due to the trial being at high risk of bias primarily due to lack of blinding, indirectness and the outcome estimates being imprecise. Cholecystectomy subgroup results are reported in the abstract. Results for both subgroups were similar. There was no difference in all-cause mortality between people receiving aggressive transfusions and those receiving conservative transfusions. No deaths occurred in either subgroup. There were no differences between the aggressive transfusion group and conservative transfusion group in the number of people developing: • an acute chest syndrome, risk ratio (RR) 0.84 (95% confidence interval (CI) 0.38 to 1.84) (one trial, 230 participants, very low-quality evidence); • vaso-occlusive crisis, risk ratio 0.30 (95% CI 0.09 to 1.04) (one trial, 230 participants, very low quality evidence); • serious infection, risk ratio 1.75 (95% CI 0.59 to 5.18) (one trial, 230 participants, very low-quality evidence); • any perioperative complications, RR 0.75 (95% CI 0.36 to 1.55) (one trial, 230 participants, very low-quality evidence); • a transfusion-related complication, RR 1.85 (95% CI 0.89 to 3.88) (one trial, 230 participants, very low-quality evidence). Preoperative transfusion versus no preoperative transfusion Two trials (434 participants) compared a preoperative transfusion plus standard care to a group receiving standard care. Overall, the quality of the evidence was low to very low across different outcomes according to GRADE methodology. This was due to the trials being at high risk of bias due to lack of blinding, and outcome estimates being imprecise. One trial was stopped early because more people in the no transfusion arm developed an acute chest syndrome. There was no difference in all-cause mortality between people receiving preoperative transfusions and those receiving no preoperative transfusions (two trials, 434 participants, no deaths occurred). There was significant heterogeneity between the two trials in the number of people developing an acute chest syndrome, a meta-analysis was therefore not performed. One trial showed a reduced number of people developing acute chest syndrome between people receiving preoperative transfusions and those receiving no preoperative transfusions, risk ratio 0.11 (95% confidence interval 0.01 to 0.80) (65 participants), whereas the other trial did not, RR 4.81 (95% CI 0.23 to 99.61) (369 participants). There were no differences between the preoperative transfusion groups and the groups without preoperative transfusion in the number of people developing: • a vaso-occlusive crisis, Peto odds ratio (OR) 1.91 (95% confidence interval 0.61 to 6.04) (two trials, 434 participants, very low-quality evidence). • a serious infection, Peto OR 1.29 (95% CI 0.29 to 5.71) (two trials, 434 participants, very low-quality evidence); • any perioperative complications, RR 0.24 (95% CI 0.03 to 2.05) (one trial, 65 participants, low-quality evidence). There was an increase in the number of people developing circulatory overload in those receiving preoperative transfusions compared to those not receiving preoperative transfusions in one of the two trials, and no events were seen in the other trial (no meta-analysis performed).

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised trials to determine whether conservative preoperative blood transfusion is as effective as aggressive preoperative blood transfusion in preventing sickle-related or surgery-related complications in people with HbSS disease. There is very low quality evidence that preoperative blood transfusion may prevent development of acute chest syndrome. Due to lack of evidence this review cannot comment on management for people with HbSC or HbSβ⁺ disease or for those with high baseline haemoglobin concentrations.

Sickle Cell Disease is Associated with Increased Morbidity, Resource Utilization, and Readmissions after Common Abdominal Surgeries: A Multistate Analysis, 2007-2014

INTRODUCTION

Sickle cell disease (SCD), the most commonly inherited hemoglobinopathy in the United States, increases the likelihood of postoperative complications, resulting in higher costs and readmissions. We used a retrospective cohort study to explore SCD's influence on postoperative complications and readmissions after cholecystectomy, appendectomy, and hysterectomy.

METHODS

We used an administrative database's 2007-2014 data from California, Florida, New York, Maryland, and Kentucky.

RESULTS

1,934,562 patients aged ≥18 years were included. Compared to non-SCD patients, SCD patients experienced worse outcomes: increased odds of blood transfusion and major and minor complications, higher adjusted odds of 30- and 90-day readmissions, longer length of stay, and higher total hospital charges.

CONCLUSION

Sickle cell disease patients are at high risk for poor outcomes based on their demographic characteristics. Therefore, perioperative physicians including hematologists, anesthesiologists, and surgeons need to take this knowledge into consideration for management and counselling of SCD patients on the risks of surgery and recovery.

American Society of Hematology 2020 guidelines for sickle cell disease: transfusion support

BACKGROUND

Red cell transfusions remain a mainstay of therapy for patients with sickle cell disease (SCD), but pose significant clinical challenges. Guidance for specific indications and administration of transfusion, as well as screening, prevention, and management of alloimmunization, delayed hemolytic transfusion reactions (DHTRs), and iron overload may improve outcomes.

OBJECTIVE

Our objective was to develop evidence-based guidelines to support patients, clinicians, and other healthcare professionals in their decisions about transfusion support for SCD and the management of transfusion-related complications.

METHODS

The American Society of Hematology formed a multidisciplinary panel that was balanced to minimize bias from conflicts of interest and that included a patient representative. The panel prioritized clinical questions and outcomes. The Mayo Clinic Evidence-Based Practice Research Program supported the guideline development process. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to form recommendations, which were subject to public comment.

RESULTS

The panel developed 10 recommendations focused on red cell antigen typing and matching, indications, and mode of administration (simple vs red cell exchange), as well as screening, prevention, and management of alloimmunization, DHTRs, and iron overload.

CONCLUSIONS

The majority of panel recommendations were conditional due to the paucity of direct, high-certainty evidence for outcomes of interest. Research priorities were identified, including prospective studies to understand the role of serologic vs genotypic red cell matching, the mechanism of HTRs resulting from specific alloantigens to inform therapy, the role and timing of regular transfusions during pregnancy for women, and the optimal treatment of transfusional iron overload in SCD.

Perioperative care of children with sickle cell disease: A systematic review and clinical recommendations

Children with sickle cell disease (SCD) require specific perioperative care, and clinical practice in this area remains poorly defined. We aimed to conduct a systematic, PRISMA-based review of the literature, available clinical guidelines and practice recommendations. We also aimed to extract any valuable information for the "best of available-evidence"-based prevention of perioperative adverse events in children with SCD, and highlight the most urgent priorities in clinical research. As data sources, US National Library of Medicine, Medline, National Guideline Clearinghouse, International Guideline Network, TRIP databases were searched for any content until January 2019. We also included institutional, consortia and expert group guidelines. Included were reports/guidelines in English, French, German, and Italian. Excluded were reports on obstetrical and fetal management. We identified 202 reports/guidelines fulfilling the criteria outlined above. A majority focused on visceral, cardiovascular and orthopedic surgery procedures, and only five were multicenter randomized controlled trials and two prospective randomized studies. After grading of the quality of the evidence, the extracted data was summarized into clinical recommendations for daily practice. Additionally, we designed a risk-grading algorithm to identify contexts likely to be associated with adverse outcomes. In conclusion, we provide a systematic PRISMA-based review of the existing literature and ancillary practice and delineate a set of clinical recommendations and priorities for research.