Retrograde autologous priming in cardiac surgery: a systematic review and meta-analysis

OBJECTIVES

Guidelines recommend retrograde autologous priming (RAP) of the cardiopulmonary bypass circuit. However, the efficacy and safety of RAP is not well-established. We performed a systematic review and meta-analysis to determine the effects of RAP on transfusion requirements, morbidity and mortality.

METHODS

We searched Cochrane Central Register of Controlled Trials, Medline, ScienceDirect, Cumulative Index to Nursing and Allied Health Literature and Embase for randomized controlled trials (RCTs) and observational studies comparing RAP to no-RAP. We performed title and abstract review, full-text screening, data extraction and risk of bias assessment independently and in duplicate. We pooled data using a random effects model.

RESULTS

Twelve RCTs (n = 1206) and 17 observational studies (n = 3565) were included. Fewer patients required blood transfusions with RAP [RCTs; risk ratio 0.58 [95% confidence interval (CI): 0.51, 0.65], P < 0.001, and observational studies; risk ratio 0.65 [95% CI: 0.53, 0.80], P < 0.001]. The number of units transfused per patient was also lower among patients who underwent RAP (RCTs; mean difference -0.38 unit [95% CI: -0.72, -0.04], P = 0.03, and observational studies; mean difference -1.03 unit [95% CI: -1.76, -0.29], P < 0.006).

CONCLUSIONS

This meta-analysis supports the use of RAP as a blood conservation strategy since its use during cardiopulmonary bypass appears to reduce transfusion requirements.

[Gastrointestinal complications after on-pump cardiac surgery]

OBJECTIVE

To determine the incidence and independent predictors of gastrointestinal complications (GICs) following on-pump cardiac surgery.

MATERIAL AND METHODS

We retrospectively analyzed data of 9559 adults who underwent cardiac surgery in 2012-2017. Two groups of patients were distinguished: group 1 - 47 (0.5%) patients with abdominal complications followed by urgent surgery; group 2 - 9512 (95.5%) patients without complications or effective therapy.

CONCLUSION

1. Predictors of gastrointestinal complications: age >65 years, previous AF (p=0.011) and multifocal atherosclerosis (p=0.016), LV EF <40% (p=0.039), aortic cross-clamping time > 90 min (p=0.021), intraoperative blood loss over 600 ml (p=0.002), postoperative serum creatinine >140 μmol/l (p=0.005), mechanical ventilation >24 hours (p=0.023).

2. Reduced hemodilution during CPB, warm blood cardioplegia, higher perioperative values of Hb, Ht and IDO2 during cardiopulmonary bypass can prevent ischemic injury of abdominal organs during prolonged cardiac surgery.

Retrograde Autologous Priming in Cardiac Surgery: Results From a Systematic Review and Meta-analysis

BACKGROUND

Retrograde autologous priming (RAP) before cardiopulmonary bypass (CPB) may minimize allogeneic red cell transfusion. We conducted a systematic review of the literature to examine the impact of RAP on perioperative allogeneic red cell transfusions in cardiac surgical patients.

METHODS

This study involved a systematic review and meta-analysis of randomized controlled trials (RCTs) and observational studies evaluating the use of RAP in cardiac surgery involving CPB. The primary outcome was intraoperative allogeneic red cell transfusion. Secondary outcomes included whole hospital allogeneic transfusions and adverse events such as acute kidney injury (AKI) and stroke.

RESULTS

A total of 11 RCTs (n = 1337 patients) were included, comparing RAP patients (n = 674) to control (n = 663). In addition, 10 observational studies (n = 2327) were included, comparing RAP patients (n = 1257) to control (n = 1070). Overall, RAP was associated with a significantly reduced incidence of intraoperative red cell transfusion (n = 18 studies; odds ratio [OR] = 0.34; 95% confidence interval [CI], 0.22-0.55, P < .001) compared to controls. This effect was seen among RCTs (n = 10 studies; OR = 0.19; 95% CI, 0.08-0.45, P < .001) and observational studies (n = 8 studies; OR = 0.66; 95% CI, 0.50-0.87, P = .004) in isolation. RAP was also associated with a significantly reduced incidence of whole hospital red cell transfusion (n = 5 studies; OR = 0.28; 95% CI, 0.19-0.41, P < .001). Among the studies that reported AKI and stroke outcomes, there was no statistically significant increased odds of AKI or stroke in either RAP or control patients.

CONCLUSIONS

Based on the pooled results of the available literature, RAP is associated with a significant reduction in intraoperative and whole hospital allogeneic red cell transfusion. Use of RAP may prevent hemodilution of cardiac surgical patients and thus, lessen transfusions. Additional high-quality prospective studies are necessary to determine the ideal priming volume necessary to confer the greatest benefit without incurring organ injury.

Retrograde autologous priming to reduce allogeneic blood transfusion requirements: a systematic review

Background:

Efforts have been made to minimize transfusion of packed red blood cells in patients undergoing cardiac surgery with cardiopulmonary bypass. One method concerns retrograde autologous priming. Although the technique has been used for decades, results remain contradictory in terms of transfusion requirements.

Objective:

This systematic literature review aimed to summarize the evidence for the efficacy of retrograde autologous priming in terms of decreasing perioperative packed red blood cell requirements in adults.

Methods:

Two researchers independently searched PubMed for articles published in the past 10 years. The modified Cochrane collaboration Risk of Bias Tool and the Research Triangle Institute Item Bank were used to assess bias.

Results:

Eight studies were included, of which two randomized and six observational studies. Five studies, including one randomized study, report a significant decrease in packed red blood cell use in the retrograde autologous priming group compared to no retrograde autologous priming used. All studies are flawed by at least a high risk bias of bias score on one item of the bias assessment.

Conclusion:

Although most studies reported significantly fewer packed red blood cell transfusions in the retrograde autologous priming group, it is important to note that relatively few articles are available which are flawed by several types of bias. Prospective, randomized multi-center trials are warranted to conclude decisively on the benefits of retrograde autologous priming.

Is there any connection between method of priming extracorporeal circuit and cerebral oximetry results?

Objectives. To compare the influence of different priming techniques on cerebral oximetry results during CPB in adult patients.

Methods. This study is a single-center retrospective review of data collected from adult patients who underwent isolated CABG with CPB between January and December, 2016. The patients were divided into two standardized groups with the sole difference between them being the method of priming CPB circuit: the first one was the group where we used our modified retrograde method of priming (n = 45) and the second one was the group with standard priming (n = 45). Hematocrit, hemoglobin, cerebral oxygenation were evaluated at the following points: beginning of the operation, start of CPB, cross clamping, 15, 30, 45 minutes and the end of CPB and the end of operation.

Results. In the first group indices of cerebral oximetry were higher comparing to the second group at list of the 45 minutes of CPB (р < 0,001). For the first 15 minutes of CPB hematocrit was also higher in the first group. Priming volume and the need for blood transfusion or ultrafiltration were also smaller in the first group.

Conclusion. Modified priming technique allows to maintain higher indices of cerebral oximetry, decreases volume overload and the need for blood transfusion comparing to standard technique.

Positive impact of retrograde autologous priming in adult patients undergoing cardiac surgery: a randomized clinical trial

BACKGROUND

Adult cardiac surgery with extracorporeal circulation is known to be associated with increased risk of blood transfusion leading to adverse outcomes. Procedures like retrograde autologous priming (RAP) may reduce these negative side effects. This randomized prospective study was initiated to assess whether RAP using specifically designed RAP bag (Terumo) has immediate effects on patient outcome.

METHODS

One hundred eighteen adults undergoing elective CABG or elective aortic valve replacement were randomly assigned by a computer program into two groups: the RAP group (n = 54) in which the retrograde autologous priming was applied and the non-RAP (n = 64) group in which the same setting was used without the possibility to save priming volume. Patient demographics, preoperative characteristics and postoperative outcomes were analyzed for both groups.

RESULTS

The primary endpoint defined as rate of intraoperative blood transfusion was significantly reduced in the RAP-group (p = 0.04). The absolute risk reduction for RAP managed patients was 13.5 percent points. There were no significant differences in operation time and blood loss. No deaths and no myocardial infarctions were observed. The number of patients needed to treat to prevent at least one red blood cell transfusion was around 8 (NNT = 7.42).

CONCLUSIONS

Retrograde autologous priming is a safe and less invasive procedure which achieves clear benefits for adult cardiac surgery patients. In the light of increasing red blood cell transfusion risks and costs and the wish of patients to avoid a transfusion implementation of retrograde autologous priming is an interesting option.

TRIAL REGISTRATION

German Clinical Trials Register ID: DRKS00013512 , registered 04 December 2017.

Revisiting acute normovolemic hemodilution and blood transfusion during pediatric cardiac surgery: a prospective observational study

BACKGROUND

The majority of allogeneic transfusions occur in the perioperative setting, especially during cardiac surgery. In addition to the economic implications, there is emerging evidence that blood transfusion may increase both morbidity and mortality. Acute normovolemic hemodilution (ANH) may limit the need for blood products.

OBJECTIVES

The primary objective of this study was to determine if the method of blood collection (syringe or bag) during the ANH process impacted the platelet count and function. The secondary objectives included the need for perioperative blood transfusions during the procedure and in the intensive care unit. In addition, we assessed these outcomes' associations with ANH parameters including the method of collection, time of storage, and volume removed.

METHODS

Data were collected prospectively from 50 patients undergoing cardiac surgery on cardiopulmonary bypass over a 6-month period. Platelet count and function were measured for the ANH blood immediately after collection and again prior to transfusing to the patient at the end of cardiopulmonary bypass. Other data collected included ANH volume, length of storage, and the quantity of all blood products given throughout the perioperative period.

RESULTS

No change in platelet count or function was noted regardless of the length of time or collection method for the ANH blood. Twenty-three patients received blood or blood products in the operating room or the intensive care unit, while 27 patients received no blood transfusion during their entire hospitalization. Higher ANH volume (ml·kg^-1 ) and longer storage time were associated with a greater need for intraoperative transfusions.

CONCLUSION

Acute normovolemic hemodilution protects the platelets from the untoward effects of cardiopulmonary bypass and offers an important autologous blood product that improves hemostasis at the conclusion of surgery. Platelet count and function are preserved regardless of the method of collection or the length of storage. The volume of ANH removed appears to be an important determinant of blood product use and further understanding of the impact of this variable is a future direction of upcoming prospective research.

A Retrospective Analysis of the Influence of Ventricular Morphology on the Perioperative Outcomes After Fontan Surgery

OBJECTIVES

The objectives of this study were to evaluate the effect of ventricular morphology on perioperative outcomes during Fontan surgery.

DESIGN

Retrospective cohort study.

SETTING

Single standing, not-for-profit pediatric hospital.

PARTICIPANTS

A total of 72 patients who underwent Fontan surgery using cardiopulmonary bypass without aortic cross-clamp between January 1, 2009 and December 31, 2014.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

The patients were divided into 3 categories depending on their single-ventricle lesions: (1) LV group (n = 20): left dominant and hypoplastic right ventricle; (2) RV group (n = 37): right dominant and hypoplastic left ventricle; and (3) BV group (n = 15): biventricular or indeterminate dominance. Perioperative major adverse events were collected based on the Society of Thoracic Surgeons database. The need for perioperative allogeneic blood transfusions also was determined. The mean age was 3.3±1.7 years and the mean weight was 13.6±4.0 kg. All patients had extracardiac lateral tunnel or conduit Fontan procedures. Sixty-nine of the patients (96%) underwent tracheal extubation in the operating room. Anesthesia, surgery, and CPB times were 326±68, 239±73, and 70±41 minutes, respectively. Eleven patients (15%) required allogeneic blood products intraoperatively, while 30 patients (42%) required allogeneic blood products during the perioperative period. Length of cardiac intensive care unit stay and hospital stay (median [IQR]) were 1 [1,2] and 12 [9,18] days, respectively. There was no mortality and no significant differences between groups in major postoperative complications, anesthetic or surgical variables.

CONCLUSIONS

No difference in the immediate perioperative outcomes was noted based on ventricular morphology.

Clinical applications of retrograde autologous priming in cardiopulmonary bypass in pediatric cardiac surgery

Retrograde autologous priming (RAP) has been routinely applied in cardiac pediatric cardiopulmonary bypass (CPB). However, this technique is performed in pediatric patients weighing more than 20 kg, and research about its application in pediatric patients weighing less than 20 kg is still scarce. This study explored the clinical application of RAP in CPB in pediatric patients undergoing cardiac surgery. Sixty pediatric patients scheduled for cardiac surgery were randomly divided into control and experimental groups. The experimental group was treated with CPB using RAP, while the control group was treated with conventional CPB (priming with suspended red blood cells, plasma and albumin). The hematocrit (Hct) and lactate (Lac) levels at different perioperative time-points, mechanical ventilation time, hospitalization duration, and intraoperative and postoperative blood usage were recorded. Results showed that Hct levels at 15 min after CPB beginning (T2) and at CPB end (T3), and number of intraoperative blood transfusions were significantly lower in the experimental group (P<0.05). There were no significant differences in CPB time, aortic blocking time, T2-Lac value or T3-Lac between the two groups (P>0.05). Postoperatively, there were no significant differences in Hct (2 h after surgery), mechanical ventilation time, intensive care unit time, or postoperative blood transfusion between two groups (P>0.05). RAP can effectively reduce the hemodilution when using less or not using any banked blood, while meeting the intraoperative perfusion conditions, and decreasing the perioperative blood transfusion volume in pediatric patients.

A single-center strategy to minimize blood transfusion in neonates and children undergoing cardiac surgery

BACKGROUND

The transfusion of blood products in the setting of uncontrolled bleeding is unquestionably lifesaving. However, in many instances, the decision to transfuse is based on physician gestalt rather than medical evidence. When indications for transfusion are unclear, the benefits of blood products must be balanced against their significant risks and associated costs. As our institution is a referral center for patients of Jehovah's Witness faith, this population has pushed our development of techniques to achieve the goal of bloodless surgery. Our practices in caring for this population have become our standard practice for managing all patients undergoing congenital cardiac surgery.

OBJECTIVES

To evaluate our success in minimizing the use of blood products during pediatric cardiac surgery.

METHODS

After IRB approval, we retrospectively reviewed all patients who underwent cardiac surgery utilizing cardiopulmonary bypass (CPB), for biventricular repair procedures. The study was conducted at a single institution (Nationwide Children's Hospital (NCH)) during the period: January 1, 2013 and December 31, 2013.

RESULTS

A total of 209 patients were included. Overall, 81 patients (38.8%) and 81 of 136 (59.6%) weighing more than 6 kg received no blood products (bloodless) during their entire hospital stay. Bloodless surgery was most successful in patients weighing more than 18 kg, followed by patients weighing 6-18 kg. All 73 patients who weighed <6 kg received blood transfusion during their hospitalization.

CONCLUSION

The techniques that we have developed to initially care for our Jehovah's Witness families may be applied to other pediatric and adult surgical procedures.

Effects of retrograde autologous priming on blood transfusion and clinical outcomes in adults: a meta-analysis

Objective:

Reducing the priming volume is an effective means of decreasing hemodilution and blood transfusion during cardiopulmonary bypass (CPB). The patient’s own blood was used to replace the crystalloid in the CPB circuit by retrograde autologous priming (RAP) in order to decrease the priming volume. Therefore, we performed a meta-analysis to investigate whether RAP could reduce blood transfusion and improve clinical outcomes.

Materials and Methods:

A comprehensive search was conducted for randomized, controlled trials (RCTs) exploring RAP in PubMed, Embase, The Cochrane Library, Google Scholar and Chinese literature databases (WanFang, WeiPu and CNKI). Clinical parameters and outcomes were focused on the lowest hematocrit (Hct) during CPB, the number of patients transfused blood intraoperatively, the number of patients transfused blood perioperatively, the number of blood units transfused, 24-hour chest tube drainage, hours to extubation, length of ICU stay, and length of hospital stay.

Results:

Ten trials, with a total of 1123 patients, were included. The number of patients transfused blood intraoperatively (RR = 0.39, 95% CI = [0.29, 0.53], p<0.00001, I2 = 40%) and perioperatively (RR = 0.53, 95% CI = [0.43, 0.66], p<0.00001, I2 = 0%) and the number of blood units transfused (SMD = -0.53, 95% CI = [-0.73, -0.33], p<0.00001, I2 = 14%) were all significantly reduced in the RAP group. No differences in the hours to extubation (SMD = -0.11, 95% CI = [-0.33, 0.12], p=0.37, I2 = 0%) and the length of ICU stay (SMD = -0.17, 95% CI = [-0.41, 0.08], p=0.18, I2 = 0%) were observed between the two groups.

Conclusion:

Compared to conventional priming, RAP could reduce transfusion in adults significantly, but had no effect on clinical outcomes, comparing to conventional priming. Further studies involving RAP are expected to investigate if this technique is beneficial to the patient.