Retrograde Autologous Priming Technique to Reduce Hemodilution during Cardiopulmonary Bypass in the Pediatric Cardiac Patient.

Blood conservation techniques during pediatric congenital heart surgery continue to be a vital strategy in reducing hemodilution during cardiopulmonary bypass. Development of mini circuits, retrograde autologous priming, modified ultrafiltration, and use of a cell saver are methods adopted by pediatric heart programs to limit transfusions. Excessive hemodilution may warrant the need for transfusion in the pediatric patient, which carries significant risks in the overall care of the patient. Retrograde autologous priming is a safe and effective way to limit the amount of hemodilution, and thereby reduce the need for transfusion.

Bloodless Repair of Aortic Arch with Dual Aortic Cannulation in a Jehovah's Witness Patient.

Various methods for surgical repair of the aortic arch are described throughout the literature with many focused on cannulation techniques and degree of systemic cooling in an effort to reduce postoperative morbidities. Despite advancements in techniques, this surgery is still often associated with higher levels of blood loss and subsequent allogenic blood transfusions. Although blood products can be safely transfused to the majority of patients undergoing repair of the aortic arch, the complexity and risk is further multiplied when the patient is of Jehovah's Witness faith and refuses blood transfusions. This paper will detail our technique of surgical repair of the aortic arch in a Jehovah's Witness patient with dual aortic cannulation and our multidisciplinary approach to avoiding blood products.

Stage 1 palliation for hypoplastic left heart syndrome without the use of allogeneic tissue, with reduced allogeneic blood product exposure: a case report.

In the 30 years since Norwood described the palliative procedure for hypoplastic left heart syndrome (HLHS), many modifications have been described which have increased the survival rate of children born with this lesion. We describe further modifications which result in reduced cardiopulmonary bypass time, no cooling or circulatory arrest time, and decreased banked blood exposure. A 16-day-old infant with HLHS undiagnosed during pregnancy presented for stage 1 palliation incorporating the Mee modification, Sano right ventricle to pulmonary artery conduit, dual arterial cannulation of the innominate artery and descending aorta, single venous cannulation of the right atrium, and a bypass prime volume of 130 mL. Anticoagulation and hemostasis were monitored with the Hepcon HMS Plus Hemostasis Management System (Medtronic USA, Minneapolis, MN). Bypass commenced at normothermia. A 5.0 Gore-Tex shunt was placed for the Sano Shunt, and the aortic arch was repaired without use of homologous tissue or synthetic material using a modification of the Mee technique. Bypass time was 92 minutes with a 10 minutes cardiac ischemic time. Modified ultrafiltration (MUF) was performed for 12 minutes and heparinization was reversed with protamine. There was no significant bleeding and no indication to transfuse clotting factors. The patient's only allogeneic donor exposure was 350 mL of red blood cells during bypass necessary to achieve a post MUF hematocrit of 50% per our current institution policy for cyanotic infants. Using modified surgical and perfusion techniques along with low prime bypass circuits can result in reduced cross clamp and bypass times as well as a decrease in blood donor exposure. Hypothetical benefits include reduced operating room, ventilation, intensive care unit, and hospital times, improved neurodevelopmental outcomes, and an overall reduction in the cost of care for infants with HLHS.

The Road to Transfusion-free Craniosynostosis Repair in Children Less Than 24 Months Old: A Quality Improvement Initiative.

INTRODUCTION: Pediatric craniofacial reconstruction has historically resulted in extensive blood loss necessitating transfusion. This single-center quality improvement initiative evaluates the impact of perioperative practice changes on the allogeneic transfusion rate for children 24 months and younger of age undergoing craniofacial reconstruction. METHODS: At project initiation, an appointed core group of anesthesiologists provided all intraoperative anesthetic care for patients undergoing craniofacial reconstruction. Standardized anesthetic guidelines established consistency between providers. Using the Plan-do-check-act methodology, practice changes had been implemented and studied over a 5-year period. Improvement initiatives included developing a temperature-management protocol, using a postoperative transfusion protocol, administering intraoperative tranexamic acid, and a preincisional injection of 0.25% lidocaine with epinephrine. For each year of the project, we acquired data for intraoperative and postoperative allogeneic transfusion rates. RESULTS: A cohort of 119 pediatric patients, ages 4-24 months, underwent anterior or posterior vault reconstruction for craniosynostosis at a tertiary children's hospital between March 2013 and November 2018. Intraoperative and postoperative transfusion of allogeneic blood products in this cohort decreased from 100% preintervention to 22.7% postintervention. CONCLUSIONS: Interdepartmental collaboration and practice modifications using sequential Plan-do-check-act cycles resulted in a bundle of care that leads to a sustainable decrease in the rate of intraoperative and postoperative allogeneic blood transfusions in patients less than 24 months of age undergoing craniosynostosis repair. This bundle decreases the risk of transfusion-related morbidity for these patients. Other institutions looking to achieve similar outcomes can implement this project.

Clinical evaluation of the Terumo Capiox FX05 hollow fiber oxygenator with integrated arterial line filter.

Perfusion techniques and equipment in pediatric open heart surgery have continued to focus on decreasing prime volumes and lowering surface areas of the cardiopulmonary bypass circuit. While this has improved drastically over the last 20 years, greater demand is being placed on the perfusionist to reduce the deleterious effects of bypass without compromising safety or efficiency. Specifically, manufacturers of disposable perfusion equipment have focused on providing pediatric perfusionists with oxygenators that provide the smallest prime and surface area possible while attempting to maximize performance. Recently,Terumo Cardiovascular has introduced the Capiox FX05, a neonatal hollow fiber oxygenator that includes an integrated arterial line filter. The FX05 provides a blood flow range of 0.1-1.5 L/min and a low priming volume of 43 mL. Additionally, it is coated with X Coating, a biocompatible, hydrophilic polymer surface coating that reduces platelet adhesion and protein denaturation. The purpose of this study was to test the FX05 for gas transfer, blood path resistance, and blood handling characteristics in a standardized clinical setting. Heat exchange coefficients were also calculated during the cooling and warming period. Other data analyzed includes bypass circuit prime volumes and initial patient hematocrit along with the total operative homologous blood donor exposures. In summary, the FX05 offers good gas exchange capabilities and a low pressure drop during normal cardiopulmonary bypass parameters along with the safety of an integrated arterial line filter. Furthermore, the FX05 with integrated filter allows a reduction in overall bypass prime volume and surface area while promoting the reduction of homologous blood transfusions, optimizing hemostasis.

Evaluation of biocompatible cardiopulmonary bypass circuit use during pediatric open heart surgery.

The contact of blood with nonbiological surfaces during cardiopulmonary bypass (CPB) induces a whole body inflammatory response and increases postoperative morbidity directly related to bleeding complications and end organ dysfunction. Methods to reduce these effects have included modification of extracorporeal circuits through biocompatible coating of disposables and the application of various pharmacological agents. Biocompatible coated surfaces are designed to mimic physiologic surfaces. This study was designed to ascertain the effects of using coated circuits during pediatric CPB. After Institutional Review Board approval and parent/guardian consent, patients undergoing CPB, weighing less than 15 kg, with target CPB temperatures more than 28 degrees C, were enrolled into the Coated Circuit Group using an entirely biocompatible CPB circuit with poly(2-methoxyethylacrylate) (PMEA) and a biocompatible coated oxygenator (n = 16). Those patients were retrospectively matched to control patients having the same congenital repair with respect to patient size, surgeon, anesthesiologist, bypass time, cross-clamp time, bypass temperature, and noncoated bypass disposables; (n = 16). CPB data collected included on-bypass platelet count, hematocrit (HCT), and CPB blood product use. Postprotamine data collected in the operating room included blood product use, time from initial protamine administration to chest closure, platelet count, prothrombin time (PT), activated partial thromboplastin time (aPTT), and international normalized ratio (INR). Postoperative intensive care unit (ICU) data included blood product use, HCT, chest tube output, platelet count, PT, aPTT, INR, blood gases, lactate, and ventilator settings at 1, 2, 4, 6, 12, and 24 hours. Other data collected included intubation time, length of time to chest tube removal, and length of ICU stay. Statistical significance (p < .05) was seen in units of platelets transfused postprotamine, ventilator peak inflation pressure (PIP) on admission to the ICU, postoperative day 0 packed red blood cells (PRBC) and fresh frozen plasma (FFP) transfused, and lactate at 1, 2, 4, 6, and 12 hours postoperative. Several parameters approached statistical significance, including PRBC transfused postprotamine, time from protamine administration to chest closure, postoperative day 0 platelets transfused, and ICU stay. The data suggest that PMEA biocompatible CPB circuits can be used safely during pediatric heart surgery, resulting in a decrease in postoperative blood product use, improved postoperative lung function, and a reduction in the time spent in the ICU.

The significance of baseline cerebral oxygen saturation in children undergoing congenital heart surgery.

OBJECTIVES: Despite recent significant improvement in outcome, children undergoing surgery for correction of congenital heart defects have a persistent and troublesome mortality rate and incidence of neurologic complications. Recent data suggest that some congenital heart defects are associated with abnormal brain development and with low cerebral blood flow. We hypothesized that some children with congenital heart disease have an abnormally low baseline (preoperative) cerebral oxygen saturation (ScO2). METHODS: ScO2 was continuously recorded intraoperatively in 143 infants and children (age <18 years) undergoing repair of congenital heart defects on cardiopulmonary bypass. Baseline saturation was obtained prior to induction of anesthesia. Preoperative and postoperative saturations were correlated with the patient's physiology (cyanotic vs. acyanotic, presence of ventricular- or arterial-level left-to-right shunts) and outcome. RESULTS: Patient age ranged from 2 days to 17 years (median 8 months). Mean baseline ScO2 was 64%. Preoperative ScO2 was lower in infants with left to right shunt physiology (P < .01), but not in cyanotic infants without left-to-right shunts. Perioperative death was associated with baseline saturation less than 50%. CONCLUSIONS: Baseline ScO2 is lower in patients with left-to-right shunt physiology. Postoperative saturation is lower in patients with left-to-right shunt physiology and in cyanotic patients. Low baseline ScO2 predicts perioperative mortality in children with congenital heart disease. Measurement of ScO2 preoperatively will provide additional information for parent counseling, and preoperative optimization of ScO2 may improve outcome.

Extended support with the Terumo Baby-RX oxygenator.

The Terumo Baby-RX, a new-generation low prime oxygenator, recently has entered the perfusion market in North America. This oxygenator is designed exclusively for neonates and infants and has the smallest priming volume of any clinically available oxygenator. The BABY-RX also is treated with X Coating, Terumo's biocompatible, hydrophilic polymer surface coating that reduces platelet adhesion and protein denaturation. The oxygenator has a blood flow range of 0.1 to 1500 mL/min and operates with a minimum reservoir volume of 15 mL. A 3.2-kg patient, status post-Stage 1 Norwood, Palliation was placed on cardiopulmonary support after thrombus formation within the modified Blalock-Taussig shunt during a general surgery procedure. The extended support circuit incorporated the Baby-RX oxygenator for 17.5 hours. The oxygenator performed well over this time period at flows of 600-800 mL/min, sweep rates of 100-300 mL/min, FiO2 of 30-40%, and ACTs of 140-200 seconds. There were no indices of oxygenator failure noted within the time frame of support. After placement of a new systemic to pulmonary shunt, the patient was removed from support and the oxygenator drained of residual blood. No evidence of fiber damage or clot formation was noted. The patient had a successful support run without complications related to cardiopulmonary support.

Conversion from extracorporeal membrane oxygenation to total cardiopulmonary bypass: a simplified method.

Pediatric patients who have preoperative hemodynamic instability or postoperative cardiac decompensation may frequently require the use of extracorporeal membrane oxygenation (ECMO) for stabilization of cardiac and respiratory function. While ECMO can be a therapeutic treatment for the congenital pediatric patient, it does not allow the additional functions of a complete cardiopulmonary bypass (CPB) circuit should subsequent surgical revision in the operating room be required. This paper will discuss our approach to converting the ECMO circuit to total cardiopulmonary bypass allowing the use of cardioplegia, cardiotomy suction, and modified ultrafiltration. This technique allows the conversion to CPB without ceasing support to the critically ill patient or exposing them to additional blood products or surface area in the priming of a new extracorporeal circuit. In addition, this circuit design allows for the resumption of ECMO support utilizing the same circuit if the patient necessitates it.

A technique for performing antegrade selective cerebral perfusion without interruption of forward flow or cannula relocation for pediatric aortic arch reconstruction.

New technology and advances in extracorporeal bypass circuitry and surgical techniques have drastically improved outcomes in infants with congenital heart defects. Hypothermia with circulatory arrest has fallen out of favor in many institutions over the last decade in part from data implicating even short circulatory arrest times to long-term neurologic sequelae. Implementing continuous cerebral perfusion techniques for aortic arch reconstruction is desirable in ameliorating neurologic complications because long-term survival of complex defects can be more routinely achieved. Many centers have implemented alternative means of alleviating cerebral ischemic periods by incorporating selective antegrade or retrograde cerebral perfusion techniques. The incidence of post-operative neurologic events is low when alternative cerebral perfusion techniques are used. Many techniques used to perform continuous cerebral perfusion involve brief periods of circulatory arrest, usually for perfusion cannula repositioning. Herein we describe a technique for performing continuous antegrade cerebral perfusion without a need to interrupt forward flow.

Cerebral oxygen saturation does not normalize until after stage 2 single ventricle palliation.

BACKGROUND: In an effort to optimize neurologic outcome, cerebral oxygen saturation (SCO2) is often measured intraoperatively and postoperatively. We hypothesized that SCO2 would be related to stage of palliation in children with single ventricle congenital heart disease. METHODS: Cerebral oxygen saturation was continuously recorded intraoperatively in 34 infants and children undergoing palliative surgery on cardiopulmonary bypass for single ventricle congenital heart defects and in a control group of 12 neonates with ductus-dependent circulation undergoing complete repair. Saturations were correlated with the patient's stage and outcome. RESULTS: Baseline SCO2 was 61% in single ventricle neonates (group P1, n = 10), 55% in neonates undergoing repair (group R), 42% in infants undergoing stage 2 palliation (group P2, n = 6), and 70% in children undergoing Fontan (group P3, n = 14). Baseline was lowest (41%) in infants undergoing interstage operations (group I, n = 4). After bypass, there was a significant improvement in SCO2 to 53% in group P2 infants (p = 0.04); there were no significant changes in the other groups. By the end of the operation, there was a significant decrease in SCO2 to 48% in group P1 (p = 0.001), with other groups unchanged from baseline. There were five perioperative deaths. Cerebral oxygen saturation at the conclusion of surgery was lower in children who died (38% versus 61%, p = 0.01). CONCLUSIONS: In children with single ventricle physiology, SCO2 decreases after initial palliation, remains low before second-stage palliation, but is normal before and after the Fontan. This has implications for perioperative mortality, neurologic injury, and potentially for interim mortality. Low postoperative SCO2 predicts perioperative mortality.