Bloodless open-heart surgery in infants and children

Safety of bloodless open-heart surgery on cardiopulmonary bypass in selected children: A single center experience with minimal invasive extracorporeal circulation

INTRODUCTION

Bloodless cardiac surgery refers to open-heart surgery without blood or blood products. The cardiopulmonary bypass (CPB) circuits are primed with crystalloid solely, and there is no intraoperative blood transfusion.

METHODS

Our program considers bloodless congenital cardiac surgery with a minimal invasive extracorporeal circulation (MiECC) system for patients above 10 kg of weight. We performed a single-center retrospective cohort study of all consecutive patients undergoing bloodless cardiac surgery for congenital heart defects between January 2016 and December 2018.

RESULTS

A total of 164 patients were reviewed (86 male and 78 female) at a median age of 9.6 years (interquartile range (IQR), 4.5-15), a weight of 32 kg (IQR, 16-55), preoperative hemoglobin 13.7 g/dl (IQR, 12.6-14.9), and preoperative hematocrit of 40.4% (IQR, 37.2-44.3). Median CPB time was 81.5 min (IQR, 58-125), and median hematocrit coming off CPB was 26% (IQR, 23-29.7). The congenital heart surgery risk (STAT) category was distributed in STAT 1 for 70, STAT 2 for 80, STAT 3 for 9, and STAT 4 for 5 patients. Most patients (95%) were extubated in the operating room with a low complication rate during the hospital stay (14.6%). Only 6 (4%) patients needed a blood transfusion during the postoperative period, with a higher incidence of complications during the hospital course (p < 0.001).

CONCLUSIONS

Bloodless congenital heart surgery with MiECC system is safe in low-surgical-risk patients. Our patients had a low rate of complications and short hospital stays.

Clinical Outcomes, Blood Utilization, and Ethical Considerations for Pediatric Patients in a Bloodless Medicine and Surgery Program

BACKGROUND

Pediatric patients requesting bloodless care represent a challenging clinical situation, as parents cannot legally refuse lifesaving or optimal interventions for their children. Here, we report clinical outcomes for the largest series of pediatric inpatients requesting bloodless care and also discuss the ethical considerations.

METHODS

We performed a single-institution retrospective cohort study assessing 196 pediatric inpatients (<18 years of age) who requested bloodless care between June 2012 and June 2016. Patient characteristics, transfusion rates, and clinical outcomes were compared between pediatric patients receiving bloodless care and those receiving standard care (including transfusions if considered necessary by the clinical team) (n = 37,271). Families were informed that all available measures would be undertaken to avoid blood transfusions, although we were legally obligated to transfuse blood if the child's life was threatened. The primary outcome was composite morbidity or mortality. Secondary outcomes included percentage of patients transfused, individual morbid events, length of stay, total hospital charges, and total costs. Subgroup analyses were performed after stratification into medical and surgical patients.

RESULTS

Of the 196 pediatric patients that requested bloodless care, 6.1% (n = 12) received an allogeneic blood component, compared to 9.1% (n = 3392) for standard care patients ( P = .14). The most common indications for transfusion were perioperative bleeding and anemia of prematurity. None of the transfusions were administered under a court order. Overall, pediatric patients receiving bloodless care exhibited lower rates of composite morbidity compared to patients receiving standard care (2.6% vs 6.2%; P = .035). There were no deaths in the bloodless cohort. Individual morbid events, length of stay, and total hospital charges/costs were not significantly different between the 2 groups. After multivariable analysis, bloodless care was not associated with a significant difference in composite morbidity or mortality (odds ratio [OR], 0.37; 95% confidence interval [CI], 0.12-1.11; P = .077).

CONCLUSIONS

Pediatric patients receiving bloodless care exhibited similar clinical outcomes compared to patients receiving standard care, although larger studies with adequate power are needed to confirm this finding. There were no mortalities among the pediatric bloodless cohort. Although a subset of our pediatric bloodless patients received an allogeneic transfusion, no patients required a court order. When delivered in a collaborative and patient-centered manner, blood transfusions can be safely limited among pediatric patients.

Safe minimization of cardiopulmonary bypass circuit volume for complex cardiac surgery in a 3.7 kg neonate

Over recent years, increasing awareness has been aroused to the hazards of the utilization of donor blood products. Particularly in neonate cardiac surgery employing cardiopulmonary bypass (CPB), the relative high priming volume of the CPB system and its adjunctive components, such as hemofilters, causes severe hemodilution and, therefore, particularly during extended perfusions, customarily requires priming of the system with autologous blood components. We report on our efforts to minimize the CPB system and adjust the perfusion strategy to the goal of transfusion-free CPB in a 3.7 kg neonate scheduled for repair of transposition of the great arteries.

Perfusion technique for nonhaemic cardiopulmonary bypass prime in neonates and infants under 6 kg body weight

Background: Cardiopulmonary bypass (CPB) in neonates and infants is associated with significant haemodilution when priming of the CPB circuit is accomplished without transfusion of homologous blood components. The degree of haemodilution and, thus, the requirements for blood transfusion may be reduced when the CPB circuit is miniaturized without compromising patient safety.

Method: Between January 2002 and October 2003, selected neonates and small infants were operated on using a nonhaemic prime extracorporeal circuit. CPB priming volume could be reduced from 300 mL to 190 mL by using a dedicated neonatal CPB console with mast-mounted roller pump heads. Reduction of priming volume resulted from shortening of all CPB lines to the minimum, downsizing of all CPB lines, exclusion of unused CPB components, use of vacuum-assisted venous drainage and from close co-operation between the perfusionist, cardiac surgeon and anaesthesiologist. The reduction in priming volume was achieved without eliminating the arterial line filter as safety device.

Results: A total of nine patients weighing between 3.2 and 5.9 kg (mean 4.7 kg) and with a body surface area of 0.22 - 0.35m2 (mean 0.29m2) were operated on with the use of the modified neonatal CPB circuit and a nonhaemic prime. Bypass time varied from 38 to 167 min (mean 96 min). The mean haematocrit on CPB was 22.5% with a range of 17 - 29%. The postoperative course of all patients was uneventful.

Conclusion: A significant reduction in CPB priming volume makes nonhaemic prime CPB in neonates and small infants undergoing complex repair of congenital heart defects possible.

Paediatric CPB: Bypass in a High Risk Group

Children and particularly neonates present unique challenges during CPB. Patient age, size, underlying anatomy and surgical strategy influence the perfusion techniques and the construction of the CPB circuit. The normal changes in physiology in the first weeks of life impact upon surgical technique and outcome of repair.

Limited surgical access necessitates alternative cannulation strategies. Deep hypothermia, low flow CPB and circulatory arrest are frequently used. An understanding of the related pathophysiology is therefore required to make the correct choices and to optimise patient outcome.

Transfusion-Free Complex Cardiac Surgery With Cardiopulmonary Bypass in a 3.55-Kg Jehovah’s Witness Neonate

Complex cardiac surgery using cardiopulmonary bypass normally requires the transfusion of autologous blood components, particularly in neonates. This is predominately caused by the relatively high priming volume of the circuit with subsequent extreme hemodilution and the often extended and complex perfusions leading to progressive consumption of platelets and coagulation factors. We report on a strategy to minimize the cardiopulmonary bypass circuit and adjust the perfusion technique that resulted in transfusion-free correction of tetralogy of Fallot with an absent pulmonary valve and an aneurysm of the left pulmonary artery in a 3.55 kg Jehovah's Witness neonate boy.

Transfusion-Free Cardiac Surgery with Cardiopulmonary Bypass in a 2.2-kg Neonate

Particularly in neonates, complex cardiac surgery employing cardiopulmonary bypass normally requires the transfusion of autologous blood components. This is predominately caused by the relatively high priming volume of the circuit with subsequent extreme hemodilution. We report on a synoptic approach to avoiding transfusions in a 2.2 kg neonate with scheduled for correction of an intracardiac total anomalous pulmonary venous connection to the coronary sinus and a persistent foramen ovale. In this patient with a preoperative hemoglobin value of 16.5 g/dL, minimization of the cardiopulmonary bypass circuit, adjustment of the perfusion technique and strict reduction of blood sampling resulted in complete avoidance of transfusions during the entire course of the operation while maintaining safe hemoglobin levels, which never fell below a concentration of 8 g/mL.

The effect of bloodless pump prime on cerebral oxygenation in paediatric patients

BACKGROUND

In paediatric patients, crystalloid prime for cardiopulmonary bypass (CPB) causes further haemodilution in comparison with blood-containing prime. Thus it may affect the cerebral oxygen supply/demand balance. The purpose of the study was to compare the effect of bloodless pump prime with that of blood-containing prime on cerebral oxygenation in children.

METHODS

Thirty-six paediatric patients scheduled for elective repair of atrial or ventricular septal defect were enrolled. In Group C (n = 18), the CPB circuit was primed only with crystalloid. In Group B (n = 18), red blood cells were added to achieve a haematocrit (Hct) of 20% during CPB. The regional cerebral oxygen saturation (rSO(2)) value measured by near-infrared spectroscopy was compared between the two groups.

RESULTS

In both groups, rSO(2) decreased below baseline at the start of CPB and during rewarming (P < 0.001, for both groups during each period). At the start of CPB, haemodilution was greater in Group C than in Group B (Hct 16.1 +/- 0.7% vs. 20.7 +/- 0.5%; P < 0.01), and there was a greater reduction in rSO(2) in Group C (49.0 +/- 5.4% vs. 59.2 +/- 7.0%; P < 0.01). During rewarming, rSO(2) was significantly lower in Group C than in Group B (57.8 +/- 5.3% vs. 62.8 +/- 6.2%; P < 0.01).

CONCLUSIONS

In paediatric patients, the haemodilution associated with crystalloid priming causes a greater reduction in rSO(2) than with blood-containing prime at the starting period of CPB and the rewarming period.

Transfusion-associated graft versus host disease

OBJECTIVES

To review the epidemiology, pathophysiology, therapeutic and preventive strategies of transfusion associated graft versus host disease (TA-GVHD) and relate the findings to the critically ill child.

DESIGN

Review article of published medical literature related to TA-GVHD.

DATA SOURCES

Medline, bibliography search, published national and institutional guidelines.

STUDY SELECTION

Original publications including prospective studies, case reports, case series, laboratory studies, and animal work.

DATA EXTRACTION

Data were extracted manually after we reviewed selected articles and assessed their contribution to knowledge of TA-GVHD.

DATA SYNTHESIS

New and significant historic information from the selected publications relating to incidence, therapy, prevention, and complications of preventive therapy of TA-GVHD was incorporated.

CONCLUSIONS

Pediatric critical care practitioners should be aware of this preventable but fatal complication of cellular blood product transfusion. High-risk categories include congenital and acquired immunodeficiency, younger age, transfusion of blood donated by family members, and transfusion with fresh whole blood. Children at risk for the development of TA-GVHD include neonates, infants, and children with congenital heart disease, not restricted to children with "classic" DiGeorge syndrome. At present, risk identification and targeted prevention are the only methods to manage TA-GVHD. Aside from minimizing cellular blood product exposure, blood product irradiation is the only established and widely available method to prevent TA-GVHD. Transfusion guidelines need to reflect a balance between the incidence of TA-GVHD and the costs of instituting irradiation to selected groups or as routine transfusion policy.

Correction of cor triatriatum sinistrum in a Jehovah's Witness infant

A cor triatriatum sinistrum was successfully treated by operation in a 14-week-old infant of a Jehovah's Witness family. The child was pretreated with erythropoietin until a hemoglobin level of 14 g/dl was obtained. There was no cardiac catheterization before the operation. The operation was performed with cardiopulmonary bypass. No blood products were transfused and the hemoglobin level after performing modified ultrafiltration was 11.5 g/dl. The infant was extubated on the same day and discharged from our institution on the eighth day after surgery. Two years after surgery the child is in sinus rhythm and is developing well.

High oxygen delivery and extraction by perfluorocarbon-primed extracorporeal membrane oxygenation do not prevent anaerobic metabolism in rabbits

PURPOSE

This study was designed to evaluate the advantage of perfluorocarbon (PFC) emulsion priming for venoarterial extracorporeal membrane oxygenation (ECMO) by comparison with hydroxyethyl starch (HES) solution in rabbits (2.8 to 3.9 kg).

RESULTS

ECMO initiation was accompanied by a profound decrease in hematocrit (from 40.1% to 14.9%) in both groups. The arterial and the right atrial oxygen contents in the PFC group (n = 4; 38.5 and 11.5 mL/dL) were greater than in the HES group (n = 5; 7.0 and 5.1 mL/dL). Right atrial oxygen tension in the PFC group increased at the beginning of ECMO (from 38.4 to 51.2 mm Hg; P = .031) and remained higher than in the HES group for 60 minutes. These results indicate that oxygen supply and extraction in the PFC group were much greater than in the HES group. However, plasma lactate increased progressively during the 120-minute ECMO procedure in both groups (from 1.8 to 14.5 in the HES group, and from 2.3 to 12.2 in the PFC group).

CONCLUSION

Perfluorocarbon priming for ECMO, although providing high oxygen delivery and extraction, does not prevent anaerobic metabolism.