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.

A Randomized Pilot Trial Assessing the Role of Human Fibrinogen Concentrate in Decreasing Cryoprecipitate Use and Blood Loss in Infants Undergoing Cardiopulmonary Bypass.

The objective of this study was to determine whether treatment with human fibrinogen concentrate decreases the need for component blood therapy and blood loss in neonate and infant patients undergoing cardiopulmonary bypass. Pediatric patients (N = 30) undergoing elective cardiac surgery were randomized to receive human fibrinogen concentrate or placebo following cardiopulmonary bypass termination. The primary endpoint was the amount of cryoprecipitate administered. Secondary endpoints included estimated blood loss during the 24 h post-surgery; perioperative blood product transfusion; effects of fibrinogen infusion on global hemostasis, measured by laboratory testing and rotational thromboelastometry; and adverse events. No clinically significant differences were identified in baseline characteristics between groups. A significantly lower volume of cryoprecipitate was administered to the treatment group during the perioperative period [median (interquartile range) 0.0 (0.0-0.0) cc/kg vs 12.0 (8.2-14.3) cc/kg; P < 0.0001] versus placebo. No difference was observed between treatment groups in blood loss, laboratory coagulation tests, use of other blood components, or incidence of adverse events. FIBTEM amplitude of maximum clot firmness values was significantly higher among patients treated with human fibrinogen concentrate versus placebo (P ≤ 0.0001). No significant differences were observed in post-drug HEPTEM, INTEM, and EXTEM results. Human fibrinogen concentrate (70 mg/kg) administered after the termination of cardiopulmonary bypass reduced the need for transfusion with cryoprecipitate in a neonate and infant patient population.ClinicalTrials.gov identifier: NCT02822599.

Safety of Interhospital ECMO Transport by Low-Volume ECMO Transport Centers.

We present our 20 years of experience as a low-volume extracorporeal membrane oxygenation (ECMO) transport center from the Southeast United States. This is a retrospective chart review of all ECMO transported patients between 1998 and 2017. Of 26 patients who were ECMO transported, median age was 15.5 days, 14 patients (54%) were neonates, 18 (69%) patients had primary cardiac pathologies, and 16 (61.5%) patients had primary ECMO transport. Median distance traveled was 81 miles. All patients were on venoarterial ECMO. Complications occurred in three patients (11.5%). Survival to discharge was 69%. Neonatal and pediatric ECMO transport by a low-volume ECMO transport center is safe.

Interval changes in ROTEM values during cardiopulmonary bypass in pediatric cardiac surgery patients.

INTRODUCTION: Rotational thromboelastometry (ROTEM) has been shown to reduce the need for transfused blood products in adult and pediatric cardiac surgery patients. However, similar evidence in newborns, neonates, and young infants is lacking. We quantified ROTEM value changes in pediatric patients on cardiopulmonary bypass (CPB) before, during and after blood product transfusion. METHODS: Each surgery had at least four interventions: initiating CPB; platelet administration during rewarming phase; post-CPB and following protamine and human fibrinogen concentrate (HFC) administration; and further component therapy if bleeding persisted and ROTEM indicated a deficiency. ROTEM assays were performed prior to surgery commencement, on CPB prior to platelet administration and following 38 mL/kg platelets, and post-CPB after protamine and HFC administration. ROTEM assays were also performed in the post-CPB period after further blood component therapy administration. RESULTS: Data from 161 patients were analyzed. Regression models suggested significant changes in HEPTEM clotting time after all interventions. PLT administration during CPB improved HEPTEM α by 22.1° (p < 0.001) and FIBTEM maximum clot firmness (MCF) by 2.9 mm (p < 0.001). HFC administration after CPB termination significantly improved FIBTEM MCF by 2.6 mm (p < 0.001). HEPTEM MCF significantly increased after 3/4 interventions. HEPTEM α significantly decreased after two interventions and significantly increased after two interventions. Greatest perturbances in coagulation parameters occurred in patients ≤90 days of age. CONCLUSION: CPB induced profound perturbations in ROTEM values in pediatric cardiac surgery patients. ROTEM values improved following PLT and HFC administration. This study provides important clinical insights into ROTEM changes in pediatric patients after distinct interventions.

Correlation Between ROTEM FIBTEM Maximum Clot Firmness and Fibrinogen Levels in Pediatric Cardiac Surgery Patients.

This study evaluated whether rotational thromboelastometry (ROTEM; Tem International GmbH, Munich, Germany) FIBTEM maximum clot firmness (MCF) can be used to predict plasma fibrinogen level in pediatric patients undergoing cardiac surgery. Linear regression was conducted to predict plasma fibrinogen level using FIBTEM MCF (0.05 level of significance). Scatter plot with the regression line for the model fit was created. Fifty charts were retrospectively reviewed, and 87 independent measurements of FIBTEM MCF paired with plasma fibrinogen levels were identified for analysis. Linear regression analysis suggested a significant positive linear relationship ( P < .0001) between plasma fibrinogen levels and MCF. Both MCF intercept and slope were significantly correlated with fibrinogen level ( P < .0001). The estimated regression equation (predicted fibrinogen = 78.6 + 12.4 × MCF) indicates that a 1-mm increase in MCF raises plasma fibrinogen level by an average of 12.4 mg/dL. The statistically significant positive linear relationship observed between MCF and fibrinogen levels ( P < .001) suggests that MCF can be used as a surrogate for fibrinogen level. This relationship is of clinical relevance in the calculation of patient-specific dosing of fibrinogen supplementation in this setting.

Comparison of stored red blood cell washing techniques for priming extracorporeal circuits.

BACKGROUND: The aim of this study was to compare three different blood washing techniques and describe the differences for the composition of the washed red blood cells (RBC). METHODS: Stored RBCs less than 5 days old were washed using three different techniques. 1) Washing with normal saline with the COBE Model 2991 blood processor in the blood bank (BB-S). 2) Washing with normal saline with the Continuous AutoTransfusion System (C.A.T.S) in the operating room (OR-S). 3) Washing with Plasma-Lyte with the C.A.T.S in the operating room (OR-PL). Then, we compared the values for hemoglobin (Hb), hematocrit (Hct), blood volume, RBC volume, lactate, glucose, sodium and potassium of the three different groups. RESULTS: Forty-five units of RBCs were washed and analyzed (15 for each technique). The OR-S RBCs, when compared to the BB-S RBCs, had lower hemoglobin (g/dL) (22.8 vs 24.1, p=0.006), lower hematocrit (%) (67 vs 71, p=0.006), higher RBC volume (ml) (161 vs 130, p<0.001), higher glucose (mg/dL) (185 vs 46, p<0.001) and lower sodium (mmol/L) (153 vs 158, p<0.001). When compared to the OR-S RBCs, the OR-PL RBCs showed higher potassium (mmol/L) (5.3 vs 2, p<0.001) and lower sodium (mmol/L) (129 vs 153, p<0.001). CONCLUSION: RBCs washed with an autotransfusion device had a higher RBC volume and more physiological levels of glucose and sodium when compared with the blood processor in the blood bank. It can be an alternative option to use RBCs washed with an autotransfusion device for priming the extracorporeal circuits utilized in patients undergoing cardiac surgery.

Non-invasive cardiac output monitor validation study in pediatric cardiac surgery patients.

STUDY OBJECTIVE: To validate a non-invasive cardiac output monitor in pediatric cardiac surgery patients. DESIGN: Prospective trial. SETTING: Operating room. PATIENTS: 20 pediatric cardiac surgery patients ASA physical status 3 and 4. INTERVENTIONS: Aesculon noninvasive cardiac output monitor was used and compared to the cardiac output derived from the Fick equation. Oxygen consumption was measured and blood samples were taken from the arterial line and from the superior and inferior vena cava. MEASUREMENTS: Noninvasive cardiac output and cardiac index and Fick cardiac output and cardiac index. Oxygen consumption was measured by the TreyMed metabolic monitor. Blood samples were simultaneously drawn from the arterial line and from the superior and inferior vena cava purse string sites by the surgeon, prior to commencing cardiopulmonary bypass. Another data set was obtained right after termination of cardiopulmonary bypass. RESULTS: There was a direct, significant relationship between Fick CO/CI and NICOM CO/CI measurements. More dispersion is detected when the magnitude of the measure increases, i.e., for older and larger patients. CONCLUSIONS: There is a strong correlation between the cardiac output values derived from the Fick equation and the Aesculon non-invasive cardiac output monitor.

Risk Factors for Longer Hospital Stay Following the Fontan Operation.

OBJECTIVES: Children with functional single ventricle undergoing the Fontan operation consume considerable resources. The purpose of this study is to evaluate pre- and intraoperative risk factors for longer hospital stay and to describe the perioperative course at a single institution over a 15-year period. DESIGN: Retrospective cohort study. SETTING: A single pediatric cardiac ICU. PATIENTS: All consecutive patients undergoing a first-time Fontan operation from 2000 to 2014. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Prolonged length of stay was defined as hospital stay greater than 75 percentile at our institution after surgery. Of 218 patients who met inclusion criteria, median length of stay was 10 days (interquartile range, 8-14 d); prolonged length of stay was defined greater than or equal to 15 days. Independent pre- and intraoperative risk factors for prolonged length of stay included higher hemoglobin (odds ratio, 1.29; p = 0.003), higher mean pulmonary artery pressure (odds ratio, 1.14; p = 0.037), and lower aortic saturation (odds ratio, 0.92; p = 0.008) in the entire group. When patients with hepatic vein inclusion (following previous Kawashima) were excluded, higher hemoglobin (odds ratio, 1.24; p = 0.027), lower aortic saturation (odds ratio, 0.92; p = 0.017), and placement of a fenestration (odds ratio, 2.438; p = 0.021) were associated with prolonged length of stay. Fifty-eight patients (26.6%) had major complications defined by Pediatric Cardiac Critical Care Consortium. Placement of a fenestration (odds ratio, 2.297; p = 0.014) and longer aortic cross-clamp time (odds ratio, 1.015; p = 0.003) were independently associated with Pediatric Cardiac Critical Care Consortium major complications. CONCLUSIONS: In this series, 75% of patients had a postoperative length of stay less than or equal to 2 weeks. Preoperative factors suggesting worse hypoxemia/decreased pulmonary blood flow (higher hemoglobin and lower oxygen saturation) and increased pulmonary artery pressure were associated with prolonged length of stay. These findings may help risk stratify this complex patient population, provide more accurate family counseling, and provide preliminary data for changes in preoperative timing of the Fontan and/or changes to postoperative management strategies for those at high risk for increased ICU morbidity.

Comparison of point-of-care activated clotting time systems utilized in a single pediatric institution.

This study compares four different activated clotting time (ACT) point-of-care (POC) testing systems used at our institution for the management of patients undergoing heparin therapy. We evaluated these systems under identical conditions to determine their accuracy, reproducibility, ease of use, and cost. Two separate testing stations containing four ACT systems were used. The testing order was randomized for every sample and performed by two trained individuals. Samples of fresh heparinized whole blood were taken at regular intervals and distributed to each station. Each operator tested 50 samples, totaling 400 ACT tests. The ACT value was significantly affected by the type of machine used at both stations 1 and 2 (p < .001). Compared with all systems, the Medtronic ACT Plus Automated Coagulation Timer System (ACT Plus) resulted in the most consistent ACT values (median = 171, Interquartile Range (IQR): 169-175) and least variability (172.17 +/- 5.24). The Hemochron Signature Elite Whole Blood Microcoagulation System had the most variability (221.10 +/- 14.78) and yielded consistently higher ACT values (median = 220, IQR: 210-229.5) compared with other systems. The ACT values reported by the i-STAT Handheld and Test Cartridge Blood Analysis System (153.30 +/- 7.87) were consistently lower (median = 154, IQR: 147-161) in comparison to the ACT Plus and Medtronic HMS Plus Hemostasis Management System (180.60 +/- 7.60, median = 181, IQR: 175-186). There was no statistical difference in results between the two testing sites (p > .05) or the operators (p > .05). The significant finding of this study was the affect each system has on the ACT value. This investigation demonstrates the variability that exists among different ACT monitoring systems at our institution. The discrepant variation in ACT values that exists with the Hemochron system questions the reliability of its use in the management of patients undergoing heparin therapy.

The Fontan operation: the pursuit of associated lesions and cumulative trauma.

Our programmatic approach to the Fontan operation has evolved to include using an extracardiac conduit with aggressive presumptive treatment of associated lesions either in the catheterization laboratory or the operating room. Fenestration is used selectively based on hemodynamics, anatomy, and presence of associated lesions. We reviewed our experience to determine the effectiveness and outcome of this strategy and to assess the cumulative trauma to the patients. The records of 137 consecutive patients who underwent Fontan at Miami Children's Hospital from 1995 to 2008 were reviewed. At mean follow up of 5.76 years, freedom from death or transplantation is 94.2% (129/137). Median age at operation was 4.6 years. Longer length of stay correlated with older operative age (P = 0.0056). Pacemakers were implanted in 11.7% (16/137). Additional (not pre-Glenn or pre-Fontan) interventional catheterizations were performed in 51.8% (71/137). Additional operations were done in 10.2% (14/137). No patient has required replacement or revision of the extracardiac conduit. Our current approach to the Fontan operation provides acceptable midterm results. The pursuit of residual lesions results in a significant number of additional interventional catheterizations and operative procedures but might have an important influence on long-term survival after the Fontan procedure.

Rationale and use of perfusion variables in the 2010 update of the society of thoracic surgeons congenital heart surgery database.

Patients undergoing congenital heart surgery are at risk of morbidity and mortality. The reasons underlying this risk are complex. To identify opportunities to reduce adverse sequelae, the cardiovascular perfusion community was invited to amend existing perfusion-related fields as well as add new ones to the current version of the Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD). The International Consortium for Evidence-Based Perfusion (ICEBP) was invited by the STS-CHSD Task Force to identify and resolve ambiguities related to definitions among the 3 current perfusion-related fields as well as to propose new variables (and definitions) for inclusion in the 2010 update of the STS-CHSD. The ICEBP used teleconferences, wiki-based communication software, and e-mail to discuss current definitions and create new fields with definitions. The ICEBP created modified definitions to existing fields related to cardiovascular perfusion and also developed and defined new fields that focus on (1) techniques of circulatory arrest and cerebral perfusion, (2) strategies of myocardial protection, and (3) techniques to minimize hemodilution and allogeneic blood transfusions. Three fields in the STS-CHSD related to perfusion were redefined, and 23 new variables and definitions were selected for inclusion. Identifying and defining fields specific to the practice of perfusion are requisite for assessing and subsequently improving the care provided to patients undergoing congenital heart surgery. The article describes the methods and justification for adjudicating extant and new perfusion-related fields added to the 2010 update of the STS-CHSD.

Complications relating to perfusion and extracorporeal circulation associated with the treatment of patients with congenital cardiac disease: consensus definitions from the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease.

The International Consortium for Evidence-Based Perfusion (www.bestpracticeperfusion.org) is a collaborative partnership of societies of perfusionists, professional medical societies, and interested clinicians, whose aim is to promote the continuous improvement of the delivery of care and outcomes for patients undergoing extracorporeal circulation. Despite the many advances made throughout the history of cardiopulmonary bypass, significant variation in practice and potential for complication remains. To help address this issue, the International Consortium for Evidence-Based Perfusion has joined the Multi-Societal Database Committee for Pediatric and Congenital Heart Disease to develop a list of complications in congenital cardiac surgery related to extracorporeal circulation conducted via cardiopulmonary bypass, extracorporeal membrane oxygenation, or mechanical circulatory support devices, which include ventricular assist devices and intra-aortic balloon pumps. Understanding and defining the complications that may occur related to extracorporeal circulation in congenital patients is requisite for assessing and subsequently improving the care provided to the patients we serve. The aim of this manuscript is to identify and define the myriad of complications directly related to the extracorporeal circulation of congenital patients.

Rapid cardiopulmonary support in children with heart disease: a nine-year experience.

BACKGROUND: We developed a novel mechanical rapid cardiopulmonary support system (CPS) in 1996 to eliminate what we believed were shortcomings of conventional extracorporeal membrane oxygenation (ECMO) circuits when used in patients with congenital heart disease. We reviewed the use of this system over a nine year period to determine if we had been successful in improving results compared with ECMO and if outcomes have changed over this time. METHODS: All children supported with CPS (110 procedures) were reviewed. Noncardiac CPS cases (7) were excluded. The study population was divided into two time periods (1995 to 2000 and 2001 to 2004), which correlate with significant differences in intraoperative, postoperative, and CPS management. Patients were further analyzed by age (< or = 30 days or > 30 days), repair complexity (risk adjusted classification for congenital heart surgery [RACHS]-1 category 6 or categories 1 to 5), and length of support. RESULTS: Overall thirty day survival of cardiac CPS patients was 55% (57 of 103). Overall survival increased from 45% (23 of 51) during the first period to 65% (34 of 52) during the second period [p < or = 0.005]. Survival rates in neonates improved from 41% (11 of 27) to 56% (15 of 27) and RACHS-1 category 6 survival improved from 38% (5 of 13) to 69% (9 of 13), but neither change reached statistical significance. Intracranial hemorrhage occurred in 6.4% of all CPS patients. CONCLUSIONS: Cardiopulmonary support is an effective alternative to ECMO for pediatric cardiac support. Further, our experience suggests that patient survival may be improved by CPS compared with reported results for ECMO in cardiac patients.

Complex neonatal single ventricle palliation using antegrade cerebral perfusion.

BACKGROUND: The efficacy of antegrade cerebral perfusion (ACP) during complex neonatal single ventricle palliation requiring arch reconstruction is uncertain. We adapted the use of ACP in early 2001 in a programmatic effort to minimize the use of deep hypothermic circulatory arrest (DHCA). METHODS: We retrospectively analyzed data of 126 consecutive patients operated on between 1995 and 2004, including stage-one palliation of hypoplastic left heart syndrome, stage-one palliation for nonhypoplastic left heart syndrome, and Damus-Kaye-Stansel procedures. Patients were divided into two groups: those repaired with prolonged DHCA only (n = 67) and those with ACP (n = 59) and usually a shorter period of DHCA. Risk was further stratified into high risk (weight < or = 2.5 kg or other cardiac lesion) and usual risk for each group. RESULTS: Survival at 30 days in the usual-risk groups was 72.0% DHCA and 93.2% ACP (p < or = 0.025), and in the high-risk groups it was 61.5% DHCA and 80% ACP (not significant). One-year survival in the usual-risk groups was 57.4% DHCA and 84.1% ACP (p < or = 0.01), and in the high-risk groups it was 38.5% DHCA and 46.7% ACP (not significant). Overall survival to date is 52.2% DHCA and 71.2% ACP (p < or = 0.5). CONCLUSIONS: There is a statistically significant survival advantage for usual-risk patients with the use of ACP. Although there is a trend to improved survival in the high-risk groups, it does not reach statistical significance and long-term outcomes in these patients remains disappointing. We continue to use ACP and believe it contributes to an overall survival advantage in our institution.

Patterns of lactate values after congenital heart surgery and timing of cardiopulmonary support.

BACKGROUND: We sought to determine if postoperative serial lactate determinations follow predictable patterns that could be useful in directing management, especially the initiation of postoperative mechanical cardiopulmonary support (CPS). METHODS: Eight patients undergoing CPS in a 2-year period and 147 patients not requiring postoperative CPS in 6 months of that period were stratified into 6 categories based on short-term risk for mortality (1 being the lowest risk). Lactate values for the first 48 hours postoperatively were retrospectively analyzed. RESULTS: Survivors not requiring CPS in category 6 (n = 16) followed a distinct pattern different from those of categories 1 through 4 (n = 128). Review of postoperative CPS survivors (n = 4) indicated that CPS was initiated electively without cardiac arrest in all 4, and lactate values showed a downward trend within 12 hours of initiation in all cases (mean lactate, 10.12 +/- 1.88 mmol/L; range, 1.4 to 16 mmol/L; mean initiation time, 16.5 hours postoperatively). Three fourths of the CPS nonsurvivors suffered cardiac arrest before CPS and showed rising lactate values despite support (mean lactate, 11.95 +/- 1.37 mmol/L; range, 1.6 to 18.6 mmol/L; mean initiation time, 21.25 hours postoperatively). Indications for initiation of CPS in patients with elevated lactate values were reviewed. Two thirds of patients who died without CPS had preterminal cardiac arrest. CONCLUSIONS: We have defined the normal pattern of postoperative lactate values in our institution. These data suggest that an abnormal lactate pattern may be useful in determining the timing of CPS initiation in hemodynamically stable patients with high or rising lactate values, before cardiac arrest or end organ damage.

Interventional catheterization performed in the early postoperative period after congenital heart surgery in children.

OBJECTIVES: The purpose of this study was to examine the safety and efficacy of interventional catheterization performed early after congenital heart surgery. BACKGROUND: Transcatheter interventions performed in the early postoperative period are viewed as high risk. To date, there have been limited published data regarding these procedures. METHODS: All catheterizations performed within six weeks after congenital heart surgery between August 1995 and January 2001 were retrospectively reviewed. A cardiac anesthesiologist, cardiac intensivist, cardiac surgeon, and operating room team were available for all cases. Interventional procedures were performed based on clinical indications, regardless of the time elapsed from surgery. RESULTS: Sixty-two patients, median age four months (2 days to 11 years), weight 4.7 kg (2.3 to 45 kg), underwent 66 catheterizations on median postoperative day 9 (0 to 42 days). Thirty-five cases involved 50 interventional procedures. Nine patients required extracorporeal cardiopulmonary support. Success rates by procedure were: angioplasty, 100%; stent implantation, 87%; vascular/septal occlusion, 100%; and palliative pulmonary valvotomy, 75%. Complications included stent migration (one patient), cerebral vascular injury (one patient), and left pulmonary artery stenosis (one patient). Thirty procedures involved angioplasty or stent implantation, including 26 involving a recently created suture line. Suture disruption or trans-mural vascular tears were not observed. There was no procedural mortality. Thirty-day survival for patients undergoing intervention was 83%. CONCLUSIONS: Transcatheter interventions can be successfully performed in the early postoperative period. These procedures can have a positive impact on patient outcome; however, they should be performed only by a pediatric interventional cardiologist supported by a multi-disciplinary team.