Acute normovolemic hemodilution is not beneficial in patients undergoing primary elective valve surgery

Low-Volume Acute Normovolemic Hemodilution Does Not Reduce Allogeneic Red Blood Cell Transfusion in Cardiac Surgery in the Modern Era of Patient Blood Management: A Propensity Score-Matched Cohort Study

OBJECTIVES

Patients undergoing cardiac surgery often require blood transfusions, which are associated with increased morbidity and mortality. Patient blood management (PBM) strategies, including acute normovolemic hemodilution (ANH), have been implemented to minimize allogeneic transfusion requirements. Older studies suggested that ANH is associated with reduced transfusions; however, its effectiveness in the modern era of PBM remains unclear.

DESIGN

This was a retrospective cohort study.

SETTING

The study was held at a single university hospital.

PARTICIPANTS

542 patients who underwent elective cardiac surgery with cardiopulmonary bypass (CPB) using low-priming-volume circuits between January 2017 and March 2022.

INTERVENTIONS

Patients who received ANH were matched with those who did not receive ANH, using propensity scores.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was the proportion of patients who received perioperative red blood cell (RBC) transfusion. Of the 542 eligible patients, 49 ANH cases were propensity-score matched to 97 controls. The median ANH volume was 450 mL (IQR, 400-800 mL). There was no significant difference in perioperative RBC transfusion rates between the 2 groups (24.5% in the ANH group vs 30.9% in the control group, p = 0.42). The odds ratio for perioperative RBC transfusion in the ANH group versus the control group was 0.72 (95% CI, 0.32-1.55, p = 0.42).

CONCLUSIONS

Low-volume ANH was not associated with a significant reduction in perioperative allogeneic RBC transfusion during cardiac surgery with CPB using low-priming-volume circuits. The benefits of low-volume ANH in reducing the requirement for RBC transfusion in the modern era of PBM may be smaller than reported previously.

A prospective trial of acute normovolemic hemodilution in patients undergoing primary cytoreductive surgery for advanced ovarian cancer

OBJECTIVES

Our objective was to determine the safety and efficacy of acute normovolemic hemodilution (ANH) to reduce the requirement for allogenic red blood cell (RBC) transfusions in patients undergoing primary cytoreduction for advanced ovarian cancer.

METHODS

Patients undergoing primary cytoreduction for advanced ovarian cancer were enrolled in a prospective trial assessing ANH at time of surgery. Intraoperative blood withdrawal was performed to a target hemoglobin of 8.0 g/dL. A standardized transfusion protocol first using autologous then allogenic blood was applied intraoperatively and throughout hospitalization according to institutional guidelines. The primary endpoint was to determine the overall rate of allogenic RBC transfusions in the intra- and postoperative periods. A predetermined allogenic RBC transfusion rate <35% was deemed a meaningful reduction from a 50% transfusion rate in historical controls.

RESULTS

Forty-one patients consented to participate. Median blood withdrawn during ANH was 1650 mL (range, 700-3000). Cytoreductive outcomes were as follows: 0 mm, 30 (73%); 1-10 mm, 8 (20%); and >10 mm, 3 (7%) residual disease. Estimated blood loss was 1000 mL (range, 150-2700). Fourteen patients (34%) received allogenic RBC transfusions intra- or postoperatively, meeting the primary endpoint. No patients were transfused outside protocol guidelines. The rate of ≥grade 3 complications (20%) and anastomotic leaks (7%) were similar to historical controls and met predefined safety thresholds.

CONCLUSIONS

For patients with advanced ovarian cancer undergoing primary cytoreductive surgery, ANH appears to reduce allogenic RBC transfusion rates versus historical controls without increasing perioperative complications. Further evaluation of the technique is warranted.

Zika Virus and Patient Blood Management

Sporadic Zika virus infections had only occurred in Africa and Asia until an outbreak in Micronesia (Oceania) in 2007. In 2013 to 2014, several outer Pacific Islands reported local outbreaks. Soon thereafter, the virus was likely introduced in Brazil from competing athletes from French Polynesia and other countries that participated in a competition there. Transmission is thought to have occurred through mosquito bites and spread to the immunologically naive population. Being also a flavivirus, the Zika virus is transmitted by the Aedes mosquito that is endemic in South and Central America that is also the vector of West Nile virus, dengue, and chikungunya. In less than a year, physicians in Brazil reported a many-fold increase in the number of babies born with microcephaly. Despite initial skepticism regarding the causal association of the Zika virus epidemic and birth defects, extensive basic and clinical research evidence has now confirmed this relationship. In the United States, more than 4000 travel-associated infections have been reported by the middle of 2016 to the Centers for Disease Control and Prevention. Furthermore, many local mosquito-borne infections have occurred in Puerto Rico and Florida. Considering that the virus causes a viremia in which 80% of infected individuals have no symptoms, the potential for transfusion transmission from an asymptomatic blood donor is high if utilizing donor screening alone without testing. Platelet units have been shown to infect 2 patients via transfusion in Brazil. Although there was an investigational nucleic acid test available for testing donors, not all blood centers were initially required to participate. Subsequently, the US Food and Drug Administration issued a guidance in August 2016 that recommended universal nucleic acid testing for the Zika virus on blood donors.In this report, we review the potentially devastating effects of Zika virus infection during pregnancy and its implication in cases of Guillain-Barre syndrome in adults. Furthermore, we urge hospital-based clinicians and transfusion medicine specialists to implement perisurgical patient blood management strategies to avoid blood component transfusions with their potential risks of emerging pathogens, illustrated here by the Zika virus. Ultimately, this current global threat, as described by the World Health Organization, will inevitably be followed by future outbreaks of other bloodborne pathogens; the principles and practices of perioperative patient blood management will reduce the risks from not only known, but also unknown risks of blood transfusion for our patients.

Mild volume acute normovolemic hemodilution is associated with lower intraoperative transfusion and postoperative pulmonary infection in patients undergoing cardiac surgery -- a retrospective, propensity matching study

Background

Perioperative allogenic transfusion is required in almost 50% of patients undergoing cardiac surgery and is associated with higher risk of mortality and morbidity (Xue et al., Lancet 387:1905, 2016; Ferraris et al., Ann Thorac Surg 91:944–82, 2011). Acute normovolemic hemodilution (ANH) is recommended as a potential strategy during cardiac surgery, but the blood conservation effect and the degree of ANH was still controversial. There is also an increasing concern about the improved outcomes associated with ANH. Therefore, a better understanding of the effect of mild volume ANH during cardiac surgery is urgently needed.

Methods

This retrospective study included 2058 patients who underwent cardiac surgery between 2010 and 2015. The study population was split into two groups (with and without mild volume ANH). Propensity score adjustment analysis was applied. We reported the association between the use of mild volume ANH and perioperative outcomes.

Results

A total of 1289 patients were identified. ANH was performed in 358 patients, and the remaining 931 patients did not receive any ANH. Five hundred of the total patients (38.8%) received perioperative RBC transfusions, 10% (129/1289) of patients received platelet, and 56.4% (727/1289) of patients received fresh frozen plasma transfusions. Mild volume ANH administration was significantly associated with decreased intraoperative RBC transfuse rate (8.5% vs. 14.4%; p = 0.013), number of RBC units (p = 0.019), and decreased postoperative pulmonary infection (6.8 vs. 11.3%; p = 0.036) during cardiac surgery. However, there was no significant difference regarding intraoperative fresh frozen plasma (FFP) and platelet concentrate transfusions, as well as postoperative and total perioperative allogeneic transfusions. Furthermore, there was no significant difference regarding postoperative outcomes including mortality, prolonged wound healing, stroke, atrial fibrillation, reoperation for postoperative bleeding and acute kidney injury. There was also no difference in postoperative ventilation time, length of ICU and hospital stay.

Conclusion

Based on the 5-year experience of mild volume ANH in cardiac surgeries with CPB in our large retrospective cohort, mild volume ANH was associated with decreased intraoperative RBC transfusion and postoperative pulmonary infection in Chinese patients undergoing cardiac surgery. However, there was no significant difference regarding postoperative and total perioperative allogeneic transfusions.

Electronic supplementary material

The online version of this article (doi:10.1186/s12871-017-0305-7) contains supplementary material, which is available to authorized users.

Transfusion triggers for guiding RBC transfusion for cardiovascular surgery: a systematic review and meta-analysis*

OBJECTIVE

Restrictive red cell transfusion is recommended to minimize risk associated with exposure to allogeneic blood. However, perioperative anemia is an independent risk factor for adverse outcomes after cardiovascular surgery. The purpose of this systematic review and meta-analysis is to determine whether perioperative restrictive transfusion thresholds are associated with inferior clinical outcomes in randomized trials of cardiovascular surgery patients.

DATA SOURCES

The Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE from inception to October 2013; reference lists of published guidelines, reviews, and associated articles, as well as conference proceedings. No language restrictions were applied.

STUDY SELECTION

We included controlled trials in which adult patients undergoing cardiac or vascular surgery were randomized to different transfusion thresholds, described as a hemoglobin or hematocrit level below which RBCs were transfused.

DATA EXTRACTION

Two authors independently extracted data from included trials. We pooled risk ratios of dichotomous outcomes and mean differences of continuous outcomes across trials using random-effects models.

DATA SYNTHESIS

Seven studies (enrolling 1,262 participants) met inclusion criteria with restrictive and liberal transfusion thresholds most commonly differing by a hemoglobin of 1 g/dL or hematocrit of 6-7%, resulting in decreased transfusions by 0.71 units of RBCs (95% CI, 0.31-1.09, p = 0.0002) without an associated change in adverse events: mortality (risk ratio, 1.12; 95% CI, 0.65-1.95; p = 0.60), myocardial infarction (risk ratio, 0.94; 95% CI, 0.30-2.99; p = 0.92), stroke (risk ratio, 1.15; 95% CI, 0.57-2.32; p = 0.70), acute renal failure (risk ratio, 0.98; 95% CI, 0.64-1.49; p = 0.91), infections (risk ratio, 1.23; 95% CI, 0.85-1.78; p = 0.27), or length of stay. There was no between-trial heterogeneity for any pooled analysis. Including four pediatric trials (456 participants) and 10 trials utilizing only intraoperative acute normovolemic hemodilution (872 participants) did not substantially change the results except that unlike the transfusion threshold trials, the hemodilution trials did not reduce the proportion of patients transfused (interaction p = 0.01).

CONCLUSIONS

Further randomized controlled trials are necessary to determine the optimal transfusion strategy for patients undergoing cardiovascular surgery.

Alternatives to blood transfusion

The use of alternatives to allogeneic blood continues to rest on the principles that blood transfusions have inherent risks, associated costs, and affect the blood inventory available for health-care delivery. Increasing evidence exists of a fall in the use of blood because of associated costs and adverse outcomes, and suggests that the challenge for the use of alternatives to blood components will similarly be driven by costs and patient outcomes. Additionally, the risk-benefit profiles of alternatives to blood transfusion such as autologous blood procurement, erythropoiesis-stimulating agents, and haemostatic agents are under investigation. Nevertheless, the inherent risks of blood, along with the continued rise in blood costs are likely to favour the continued development and use of alternatives to blood transfusion. We summarise the current roles of alternatives to blood in the management of medical and surgical anaemias.

Phase II comparison study of intraoperative autotransfusion for major oncologic procedures

BACKGROUND

Intraoperative autotransfusion (IOAT) has been avoided in oncologic surgery because of possible tumor cell dissemination. Through a prior Phase I study, we demonstrated that malignant cells are not present in blood filtered for IOAT. We hypothesized that autotransfusion could be safely used for patients undergoing major oncologic procedures and reduce the need for allogeneic blood.

MATERIALS AND METHODS

A Phase II, IRB-approved, prospective evaluation was conducted of patients undergoing gastrointestinal oncologic procedures. All procedures were conducted with blood salvaged for IOAT, and the collected volume was autotransfused if it was >100 ml. Quality of life (QoL) was assessed by questionnaire at regular intervals.

RESULTS

A total of 92 patients were enrolled with median age of 56 years. The most commonly performed procedures were hepatectomy (47%) and pancreaticoduodenectomy (26%). The median preoperative hemoglobin (Hgb) was 13.1 (range, 9-16), and the median estimated blood loss was 350 ml (range, 20-4000 ml). Of the 92 total patients, 32 (35%) received IOAT with a median volume of 255 ml (range, 117-1499 ml). Multivariate analysis identified that patients with preoperative Hgb >11 g/dl (P = .02), and blood loss of 400-900 ml (P = .03) benefited from IOAT with a reduction in postoperative blood transfusion rate. Patients with discharge Hgb >10 g/dl showed higher mean QoL scores throughout their recovery. At a median follow-up of 18 months, the rates of recurrence in the IOAT and the non-IOAT groups were equivalent (38 vs. 39%, P = .9).

CONCLUSIONS

Intraoperative autotransfusion can be used safely and effectively for major oncologic procedures. Furthermore, degree of discharge anemia is associated with lower quality of life in patients undergoing oncologic gastrointestinal surgery.