Acute Kidney Injury With a Miniaturized Extracorporeal Circuit for Neonatal Cardiopulmonary Bypass.

OBJECTIVES: The objectives of this study were to evaluate the incidence and to identify risk factors for acute kidney injury (AKI) in neonates undergoing cardiopulmonary bypass (CPB) with a miniaturized bloodless primed extracorporeal circuit. DESIGN: A retrospective cohort study. SETTING: A single-center, tertiary academic hospital. PARTICIPANTS: Data of 462 patients were analyzed. INTERVENTIONS: With a retrospective analysis of neonates undergoing CPB with bloodless priming between May 2007 and August 2019, the incidence of AKI was determined according to the neonatal Kidney Disease: Improving Global Outcomes classification. Multivariate logistic regression analyses were performed to determine risk factors for AKI. MEASUREMENTS AND MAIN RESULTS: The incidence of AKI was 41.1% (190 of 462); 30.3% (n = 140) had mild stage 1, 6.5% (n = 30) reached stage 2, and 4.3% (n = 20) reached stage 3. Multivariate logistic regression showed that degree of hypothermia (p = 0.05), duration of CPB (p = 0.03), and lower baseline serum creatinine (p < 0.001) were associated independently with AKI. In the authors' patient population, patients without transfusion of donor-derived erythrocytes had a lower incidence of AKI (p = 0.003). AKI stages 2 and 3 were associated with longer duration of mechanical ventilation (p = 0.008) and increased length of stay in the intensive care unit (p = 0.03). CONCLUSIONS: With a miniaturized CPB circuit and bloodless priming, the AKI incidence was well within the range consistent with previously reported studies from other institutions.

Coagulation Profile of Neonates Undergoing Arterial Switch Surgery With Crystalloid Priming of the Cardiopulmonary Bypass Circuit.

OBJECTIVES: The aim was to evaluate changes in the coagulation profile of cyanotic neonates, to analyze the effects of cardiopulmonary bypass (CPB) with crystalloid priming on their coagulation status, and to determine factors predicting a requirement for hemostasis-derived transfusion. DESIGN: Retrospective cohort. SETTING: Single-center, tertiary academic hospital. PARTICIPANTS: In total, 100 consecutive neonates who underwent arterial switch surgery between December 2014 and June 2020. INTERVENTIONS: Rotational thromboelastometry (ROTEM) and coagulation parameters before surgery and before termination of CPB were evaluated. Transfusion of platelets, fresh frozen plasma, and fibrinogen, defined as hemostasis-derived transfusion (HD transfusion), were determined. Patients with and without HD transfusion were compared to identify predictors. MEASUREMENTS AND MAIN RESULTS: After CPB, fibrinogen was reduced by 24.5% (interquartile range [IQR] 8.9-32.1) to 201 mg/dL (IQR 172-249), resulting in a reduction of FIBTEM A10 by 20% (1.8-33.3) to 8 mm (6-11). The platelet count decreased by a median of 47.2% (25.6-61.3) to 162 × 103/µL (119-215). However, the median fibrinogen concentration and platelet count remained within normal range. Neonates with abnormal ROTEM results were more likely to receive HD transfusions. The HD transfusions were more likely with lower preoperative FIBTEM maximum clot firmness values (p = 0.031), lower hemoglobin concentrations at termination of CPB (p = 0.02), and longer CPB duration (p = 0.017). Perioperative hemostasis without any HD transfusion was achieved in 64 neonates. CONCLUSIONS: Guidance from ROTEM analyses facilitates hemostasis management after neonatal CPB. Circuit miniaturization with transfusion-free CPB is associated with acceptable changes in ROTEM in most patients, and allows sufficient hemostasis without any HD transfusions in most patients.

Asanguineous Cardiopulmonary Bypass in Infants: Impact on Postoperative Mortality and Morbidity.

BACKGROUND: We routinely start cardiopulmonary bypass (CPB) for pediatric congenital heart surgery without homologous blood, due to circuit miniaturization, and blood-saving measures. Blood transfusion is applied if hemoglobin concentration falls under 8 g/dL, or it is postponed to after coming off bypass or after operation. How this strategy impacts on postoperative mortality and morbidity, in infants weighing ≤ 7 kg? METHODS: Six-hundred fifteen open-heart procedures performed from January 2014 to June 2018 were selected. One-hundred sixty-three patients (26.5%) were transfused on CPB (group 1), while 452 (73.5%) patients were not transfused on CPB (group 2). Operative risk and complexity were similar in both groups. Postoperative mortality and morbidity were compared. Multiple logistic regression was used to detect factors independently associated with outcome. RESULTS: Observed mortality in nontransfused group (0.7% = 3/452) was significantly lower than expected (4.2% = 19/452): p = 0.0007, and much lower than in transfused group (6.7% = 11/163): p < 0.0001. CPB transfusion (p = 0.001) was independently associated with mortality, either acting as the sole factor or in combination with the Society of Thoracic Surgeons morbidity score (p = 0.013). Patients not transfused during CPB required less frequently vasoactive inotropic drugs (p = 0.011) and duration of their mechanical ventilation was shorter (93 ± 134 hours) than for transfused patients (142 ± 170 hours): p = 0.0003. CPB transfusion was an independent determinant factor for morbidity (p = 0.05), together with body weight (p < 0.0001), vasoactive inotropic score (p < 0.0001), CPB duration (p = 0.001), and postoperative transfusion (p = 0.009). CONCLUSION: The strategy of transfusion-free CPB course, feasible in most patients ≤ 7kg, was associated with improved outcome. Asanguineous priming of CPB circuit should become standard, even in neonates and infants.

Cardiopulmonary Bypass Strategy to Facilitate Transfusion-Free Congenital Heart Surgery in Neonates and Infants.

Priming the cardiopulmonary bypass (CPB) circuit without the addition of homologous blood constitutes the basis of blood-saving strategies in open-heart surgery. For low-weight patients, in particular neonates and infants, this implies avoidance of excessive hemodilution during extracorporeal circulation. The circuit has to be miniaturized and tubing must be cut as short as possible to reduce the priming volume to prevent unacceptable hemodilution with initiating CPB. During perfusion, measures should be taken to prevent blood loss from the primary circuit to avoid replacement by additional volume. Favorable factors such as mild hypothermia/normothermia and high heparin concentrations during extracorporeal circulation promote earlier hemostasis after coming off bypass.Lower mortality score, first chest entry, higher hemoglobin concentration before going on bypass, and shorter CPB duration support transfusion-free CPB procedure. Reduced postoperative morbidity and mortality were observed when CPB was performed without blood transfusion. In our experience, this can be achieved in at least 70% of CPBs, even in low-weight patients.Bloodless CPB circuit priming should become a widespread reality, even in neonates and young infants, in any open-heart procedure.

Bloodless priming of the cardiopulmonary bypass circuit: determinants of successful transfusion-free operation in neonates and infants with a maximum body weight of 7 kg.

We currently perform open-heart procedures using bloodless priming of cardiopulmonary bypass circuits regardless of a patient's body weight. This study presents results of this blood-saving approach in neonates and infants with a body weight of up to 7 kg. It tests with multivariate analysis factors that affect perioperative transfusion. A total of 498 open-heart procedures were carried out in the period 2014-2016 and were analysed. Priming volume ranged from 73 ml for patients weighing up to 2.5 kg to 110 ml for those weighing over 5 kg. Transfusion threshold during cardiopulmonary bypass was 8 g/dl of haemoglobin concentration. Transfusion factors were first analysed individually. Variables with a p-value lower than 0.2 underwent logistic regression. Extracorporeal circulation was conducted without transfusion of blood in 335 procedures - that is, 67% of cases. Transfusion-free operation was achieved in 136 patients (27%) and was more frequently observed after arterial switch operation and ventricular septal defect repair (12/18=66.7%). It was never observed after Norwood procedure (0/33=0%). Lower mortality score (p=0.001), anaesthesia provided by a certain physician (p=0.006), first chest entry (p=0.013), and higher haemoglobin concentration before going on bypass (p=0.013) supported transfusion-free operation. Early postoperative mortality was 4.4% (22/498). It was lower than expected (6.4%: 32/498). In conclusion, by adjusting the circuit, cardiopulmonary bypass could be conducted without donor blood in majority of patients, regardless of body weight. Transfusion-free open-heart surgery in neonates and infants requires team cooperation. It was more often achieved in procedures with lower mortality score.

Asanguineous priming of miniaturized paediatric cardiopulmonary bypass circuits for congenital heart surgery: independent predictors associated with transfusion requirements and effects on postoperative morbidity.

OBJECTIVES: In paediatric cardiac surgery, body weight-adjusted miniaturized cardiopulmonary bypass (CPB) circuits within a comprehensive blood-sparing approach can reduce transfusion requirements. Haemodilution resulting from mixing the patient's blood with a CPB crystalloid solution may be reduced to the extent that asanguineous priming becomes possible. Therefore, we adopted asanguineous priming in our clinical routine. Our goal was to report the effects of asanguineous priming on transfusion requirements, clinical features associated with transfusion and effects on in-hospital morbidity. METHODS: Data of all paediatric patients with body weights up to 15 kg treated within a 2-year period between May 2013 and May 2015 were retrospectively analysed. The incidence of transfusions was analysed and periprocedural haemoglobin concentrations were evaluated. Predictors associated with transfusion requirements, duration of ventilation or length of stay in the intensive care unit were evaluated by multivariable analyses. RESULTS: Data from 579 patients with body weights up to 15 kg were analysed. The ability to avoid transfusion depended on body weight: in patients <3 kg, the rate (95% confidence interval) of transfusion during CPB was 0.53 (0.37-0.69), and in patients >8 kg, the rate was 0.14 (0.10-0.19). The respective rates of transfusions throughout the hospital stay were 1.00 (0.90-1.00) and 0.67 (0.60-0.73). Body weight, preoperative haemoglobin concentration, duration of CPB and palliative surgery were independently associated with transfusion during CPB. Transfusion, particularly transfusion during CPB, was independently associated with longer mechanical ventilation time (hazard ratio 3.52, confidence interval 2.66-4.65) and length of stay in the intensive care unit (hazard ratio 2.52, confidence interval 1.91-3.32). CONCLUSIONS: Asanguineous priming is feasible using miniaturized CPB circuits. It may help to avoid blood transfusions in patients on CPB and reduce transfusion requirements and transfusion-related morbidity.

Additional veno-venous gas exchange as a problem-solving strategy for an oxygenator not transferring oxygen in paediatric cardiopulmonary bypass.

OBJECTIVES: Oxygenator failure during cardiopulmonary bypass constitutes a life-threatening event, especially when perfusion is conducted under normothermia. An alternative solution to emergency oxygenator changeover is described. METHODS: A supplementary oxygenator is added in the venous line without interrupting perfusion. De-airing is achieved through the cardiotomy reservoir. Oxygen supply is adapted to ensure physiologic partial oxygen pressure. RESULTS: On 5 occasions in the past 4 years, Capiox Baby FX 05 oxygenator (n = 4) and Capiox FX15 (n = 1) failed to exchange blood gases after bypass run ranging from 290 min to 563 min. Hypoxia ensued with partial oxygen pressure values of 49-79 mmHg with a fraction of inspired oxygen of 1. An additional veno-venous Terumo Capiox FX 05 oxygenator immediately improved oxygenation with resulting partial oxygen pressure increasing to at least 291 mmHg. CONCLUSIONS: An additional veno-venous oxygenator effectively corrects failing oxygenator during cardiopulmonary bypass. The method does not require circulation arrest. It does not carry the risk of air embolism. It can be carried out without any help from a second perfusionist or member of operation team.

Accuracy of predicted haemoglobin concentration on cardiopulmonary bypass in paediatric cardiac surgery: effect of different formulae for estimating patient blood volume.

INTRODUCTION: When applying a blood-conserving approach in paediatric cardiac surgery with the aim of reducing the transfusion of homologous blood products, the decision to use blood or blood-free priming of the cardiopulmonary bypass (CPB) circuit is often based on the predicted haemoglobin concentration (Hb) as derived from the pre-CPB Hb, the prime volume and the estimated blood volume. We assessed the accuracy of this approach and whether it may be improved by using more sophisticated methods of estimating the blood volume. PATIENTS AND METHODS: Data from 522 paediatric cardiac surgery patients treated with CPB with blood-free priming in a 2-year period from May 2013 to May 2015 were collected. Inclusion criteria were body weight <15 kg and available Hb data immediately prior to and after the onset of CPB. The Hb on CPB was predicted according to Fick's principle from the pre-CPB Hb, the prime volume and the patient blood volume. Linear regression analyses and Bland-Altman plots were used to assess the accuracy of the Hb prediction. Different methods to estimate the blood volume were assessed and compared. RESULTS: The initial Hb on CPB correlated well with the predicted Hb (R2=0.87, p<0.001). A Bland-Altman plot revealed little bias at 0.07 g/dL and an area of agreement from -1.35 to 1.48 g/dL. More sophisticated methods of estimating blood volume from lean body mass did not improve the Hb prediction, but rather increased bias. CONCLUSION: Hb prediction is reasonably accurate, with the best result obtained with the simplest method of estimating the blood volume at 80 mL/kg body weight. When deciding for or against blood-free priming, caution is necessary when the predicted Hb lies in a range of ± 2 g/dL around the transfusion trigger.

Complex Cardiac Surgery on Patients with a Body Weight of Less Than 5 kg without Donor Blood Transfusion.

Performing safe cardiac surgery in neonates or infants whose parents are Jehovah's Witnesses is only possible in a coordinated team approach. An unconditional prerequisite is a cardiopulmonary bypass (CPB) circuit with a very low priming volume to minimize hemodilution. In the past decade, we have developed a functional blood-sparing approach at our institution. The extracorporeal circuit was miniaturized. This had to be recently adapted, faced with a challenge associated with the switch to high-volume crystalloid cardioplegia. A filtration circuit was added. Here, we report an open heart surgery on three consecutive children of Jehovah's Witness parents with a body weight of 2.7, 4.5, and 4.8 kg, respectively. Procedures consisted of one arterial switch operation and two repairs of complete atrioventricular septal defects. Our static priming volume of less than 90 mL resulted in a nadir hematocrit during CPB of 27.7% (Hb 8.9 g/dL) in a patient which happened to have the lowest body weight of 2.7 kg. The two other patients had their lowest hematocrit at 31.4% (Hb 10.2 g/dL). The three children could be treated without any kind of transfusion of blood which had left the circulation or its extensions, in accordance with the parents' wishes, and enjoy favorable outcomes without transfusion of blood products during their entire hospital stay.

Routine Application of Bloodless Priming in Neonatal Cardiopulmonary Bypass: A 3-Year Experience.

A restrictive transfusion strategy led us to routinely try to conduct donor-blood free open-heart surgery even in neonates. The cardio-pulmonary bypass (CPB) circuit was minimized by priming volumina at 73 ml for the smallest patients with body weight up to 2.5 kg and 85-95 ml for those with body weight of more than 2.5 kg, and by positioning the console as close as possible to operation table. Measures were applied to save blood during the procedure. Transfusion threshold of 8 g/dl hemoglobin was retained. Effort was made to avoid transfusion while on CPB or to postpone transfusion towards CPB end. From 2013 to 2015, 149 consecutive neonates underwent 150 open-heart procedures without blood in priming volume. Weight was lower than 2.5 kg in five instances. The most frequent operations were arterial switch operation (n = 54) and Norwood procedure (n = 17). Transfusion-free operation was achieved in 44 procedures. The great majority (42/44 = 95%) involved biventricular repair and included 50% (27/54) of arterial switch operations. 106 patients were transfused: 63 mostly towards CPB end, and 43 after coming off bypass. Transfusion-free procedures were associated with postoperative lower lactate concentration (p = 0.0013) and shorter duration of mechanical ventilation (p = 0.0009). Seven patients were discharged from hospital without getting any transfusion of blood or blood products. In conclusion, routine application of bloodless priming in neonatal cardiopulmonary bypass is safe and beneficial. It results into a good number (29%= 44/150) of transfusion-free operations. Postponing transfusion towards CPB end favors an overall restrictive transfusion strategy for all patients.

Red blood cell storage duration is associated with various clinical outcomes in pediatric cardiac surgery.

BACKGROUND: Recommendations on the use of fresh red blood cells (RBCs) in pediatric patients undergoing cardiac surgery are based on limited information. Furthermore, the RBC storage time cut-off of fresh units remains unknown. METHODS: Data from 139 pediatric patients who underwent cardiac surgery and received RBCs from a single unit within 14 days of storage were analyzed. To identify the optimal cut-off storage time of RBCs for transfusion, multiple multivariate analyses aimed at different outcome parameters were performed. RESULTS: 26 patients received RBC units stored for ≤3 days, while 126 patients received RBCs that were stored for 4-14 days. The latter group required more RBC transfusions and fresh frozen plasma (FFP) than the former group (19 vs. 25 ml/kg, p = 0.003 and 73% vs. 35%, p = 0.0006, respectively). In addition, the odds for the administration of FFP increased with the transfusion of RBCs stored for more than 4 days. The optimal cut-off for post-operative morbidity was observed with a storage time of ≤6 days for length of ventilation (p = 0.02) and peak of C-reactive protein (CRP; p = 0.008). CONCLUSIONS: The obtained results indicate that the hazard of blood transfusion increased with increasing storage time of RBCs. The results of this study suggest that transfusion of fresh RBCs with a storage time of ≤2 or 4 days (concerning transfusion requirements) or ≤6 days (concerning postoperative morbidity) may be beneficial in pediatric patients undergoing cardiac surgery. However, further prospective randomized studies are required in order to draw any final conclusions.

Blood transfusion determines postoperative morbidity in pediatric cardiac surgery applying a comprehensive blood-sparing approach.

OBJECTIVE: Recently we suggested a comprehensive blood-sparing approach in pediatric cardiac surgery that resulted in no transfusion in 71 infants (25%), postoperative transfusion only in 68 (24%), and intraoperative transfusion in 149 (52%). We analyzed the effects of transfusion on postoperative morbidity and mortality in the same cohort of patients. METHODS: The effect of transfusion on the length of mechanical ventilation and intensive care unit stay was assessed using Kaplan-Meier curves. To assess whether transfusion independently determined the length of mechanical ventilation and length of intensive care unit stay, a multivariate model was applied. Additionally, in the subgroup of transfused infants, the effect of the applied volume of packed red blood cells was assessed. RESULTS: The median length of mechanical ventilation was 11 hours (interquartile range, 9-18 hours), 33 hours (interquartile range, 18-80 hours), and 93 hours (interquartile range, 34-161 hours) in the no transfusion, postoperative transfusion only, and intraoperative transfusion groups, respectively (P < .00001). The corresponding median lengths of intensive care unit stay were 1 day (interquartile range, 1-2 days), 3.5 days (interquartile range, 2-5 days), and 8 days (interquartile range, 3-9 days; P < .00001). The multivariate hazard ratio for early extubation was 0.24 (95% confidence interval, 0.16-0.35) and 0.37 (95% confidence interval, 0.25-0.55) for the intraoperative transfusion and postoperative transfusion only groups, respectively (P < .00001). In addition, the cardiopulmonary time, body weight, need for reoperation, and hemoglobin during cardiopulmonary bypass affected the length of mechanical ventilation. Similar results were obtained for the length of intensive care unit stay. In the subgroup of transfused infants, the volume of packed red blood cells also independently affected both the length of mechanical ventilation and the length of intensive care unit stay. CONCLUSIONS: The incidence and volume of blood transfusion markedly affects postoperative morbidity in pediatric cardiac surgery. These results, although obtained by retrospective analysis, might stimulate attending physicians to establish stringent blood-sparing approaches in their institutions.

Effects of a comprehensive blood-sparing approach using body weight-adjusted miniaturized cardiopulmonary bypass circuits on transfusion requirements in pediatric cardiac surgery.

OBJECTIVES: Transfusion-free pediatric cardiac surgery remains a challenge, mainly owing to the mismatch between the cardiopulmonary bypass (CPB) priming volume and the infants' blood volume. Within a comprehensive blood-sparing approach, we developed body weight-adjusted miniaturized CPB circuits with priming volumes of 95, 110, and 200 mL for, respectively, infants weighing less than 3 kg, 3 to 5 kg and 5 to 16 kg. We analyzed the effects of this approach on transfusion requirements and risk factors predisposing for blood transfusion. METHODS: A total of 288 children with body weights between 1.7 and 15.9 kg were included and divided into 3 groups: No transfusion, postoperative transfusion only, and intraoperative and postoperative transfusion. Groups were compared by analysis of variance or analysis of variance on ranks. Risk factors predisposing for transfusion were identified by multivariate logistic regression. RESULTS: Of the infants, 24.7% required no transfusion, 23.6% received postoperative transfusion only and 51.7% received intraoperative and postoperative transfusion. Groups differed by age, body weight, and size and by duration of surgery, CPB, and aortic crossclamp (P<.00001). Body weight (P<.00001), CPB duration (P<.00001), and persisting cyanosis (P=.03) were predictors of intraoperative and postoperative transfusion, whereas body weight (P=.00095), reoperations (P=.0051), and cyanotic heart defects (P=.035) were associated with postoperative transfusion only. CONCLUSIONS: Our blood-sparing approach allows for transfusion-free surgery in a substantial number of infants. The strongest predictors of transfusion requirement, body weight and complexity of surgery as reflected by CPB duration, are not amenable to further improvements. Better preservation of the coagulatory system might allow for reduction of postoperative transfusion requirements.

Transfusion-free complex cardiac surgery: with use of deep hypothermic circulatory arrest in a preterm 2.96-kg Jehovah's witness neonate.

In neonates, the major obstacle to transfusion-free complex cardiac surgery is the severe hemodilution that can result from the mismatch between the priming volume of the circuit and the patients' blood volume. Herein, we report the case of a 13-day-old, 2.96-kg preterm neonate who had a hypoplastic aortic arch and atrial and ventricular septal defects. At the insistence of her Jehovah's Witness parents, we performed corrective surgery without transfusing homologous blood products--using deep hypothermic circulatory arrest in the process. A specially designed cardiopulmonary bypass circuit with a priming volume of only 95 mL was the key component of an interdisciplinary effort to avoid transfusion while maintaining the patient's safety. To our knowledge, this is the 1st report of the use of deep hypothermic circulatory arrest in blood-transfusion-free surgery to correct congenital heart defects in a small Jehovah's Witness neonate.

Minimizing intraoperative hemodilution by use of a very low priming volume cardiopulmonary bypass in neonates with transposition of the great arteries.

OBJECTIVE: Owing to the mismatch between cardiopulomary bypass priming volume and infants' blood volume, pediatric cardiac surgery is often associated with transfusion of homologous blood, which may increase the risk of perioperative complications. Here we report the impact of a very low volume (95-110 mL) cardiopulmonary bypass circuit during arterial switch operations in neonates with transposition of the great arteries on blood requirements, tissue oxygenation, and patient outcome. METHODS: Twenty-three consecutively treated neonates aged 2 to 17 days were treated with the blood-sparing approach. Asanguineous priming was used in all cases and packed red blood cells were added when hemoglobin concentration decreased below 7 g/dL. Cerebral and lower body tissue oxygenation was monitored by near-infrared spectroscopy. Intraoperative and postoperative transfusion, duration of ventilation and intensive care unit stay, wound infection, and 30-day mortality were assessed for patient outcome. RESULTS: Intraoperative blood transfusion was necessary in 6 of 23 neonates. An additional 11 neonates received postoperative blood transfusions on the intensive care unit, leaving 6 infants who received no blood at all. Preoperative hemoglobin concentration was the only predictor for intraoperative transfusion requirement (11.6 ± 0.9 and 13.3 ± 0.4 g/dL in infants with and without intraoperative transfusion, respectively). Despite marked differences in hemoglobin concentrations between infants with and without transfusion, regional tissue oxygenation increased in both groups during cardiopulmonary bypass and returned to baseline at the end of surgery. In-hospital patient outcome was similar in both groups. CONCLUSIONS: Transfusion-free complex cardiac surgery can be achieved even in neonates without jeopardizing tissue oxygenation or patient safety.

How near-infrared spectroscopy differentiates between lower body ischemia due to arterial occlusion versus venous outflow obstruction.

Small infants undergoing cardiac surgery are at high risk for regional malperfusion during cardiopulmonary bypass. We report a 13-day-old neonate who underwent reconstruction of the aortic arch and closure of atrial and ventricular septum defects. Near-infrared spectroscopy probes were placed on the forehead and the calf to monitor tissue oxygenation and hemoglobin concentrations. During rewarming, after deep hypothermic circulatory arrest, the patient's calf hemoglobin concentration immediately increased but oxygenation remained low. Repositioning of the venous cannula resolved this suspected venous congestion. Simultaneous monitoring of tissue oxygenation and hemoglobin concentration allows differentiation of arterial obstruction from venous congestion.

Rescue extracorporeal membrane oxygenation in children with refractory cardiac arrest.

We describe our experience with extracorporeal cardiopulmonary resuscitation (CPR) using extracorporeal membrane oxygenation (ECMO) in children with refractory cardiac arrest, and determine predictors for mortality. ECMO support was instituted on 42 children, median age 0.7 years (1 day-17.8 years), median weight 7.05 (range 2.7-80) kg who suffered refractory cardiac arrest (1992-2008). Patients were postcardiotomy (n=27), or had uncorrected congenital heart diseases (n=3), cardiomyopathy (n=3), myocarditis (n=2), respiratory failure (n=3), or had trauma (n=4). Cannulation site was the chest in all except for three neonates who were cannulated through the neck vessels and two children who had femoral cannulation. ECMO was successfully discontinued in 17 patients. Primary cause of mortality was neurological injury. Pre-ECMO CPR duration for survivors against those who died was a mean of 35±1.3 min vs. a mean of 46±4.2 min. Age, weight, sex, anatomic diagnosis, etiology (surgical vs. medical) were not significant predictors of poor outcome. Prolonged CPR and high-dose inotropes are significant predictors of mortality. Rescue ECMO support in children with refractory cardiac arrest can achieve acceptable survival and neurological outcomes.

Cerebral expression of neuroglobin and cytoglobin after deep hypothermic circulatory arrest in neonatal piglets.

INTRODUCTION: Deep hypothermic circulatory arrest (DHCA) is used in corrective cardiac surgery for complex congenital heart disease. Endogenous protective mechanisms may be responsible for the prevention of brain damage after hypothermic ischemia. Neuroglobin and cytoglobin are expressed in brain cells and appear to modulate hypoxic-ischemic brain injury. However, their neuroprotective potency is still not understood. Thus the aim of this study was to detect the influence exerted by DHCA on their expression. METHODS: The effects of DHCA were analyzed in a neonatal piglet model with cardiopulmonary bypass, DHCA of 60 and 120 min and subsequent reperfusion of 6h. Complete histological analysis and changes in the mRNA expression of neuroglobin and cytoglobin were measured in the brain. RESULTS: In comparison to animals without DHCA, neuroglobin expression was stable after 60 min DHCA and neuronal cell necrosis in the cortex was mild (< 10 %). Neuroglobin expression was significantly reduced after 120 min DHCA, which was accompanied by substantial neuronal cell necrosis (> 50 %). Cytoglobin expression did not differ significantly between animals with neuronal necrosis vs. sham. CONCLUSION: Constitutive expression levels of neuroglobin may explain the mild neuronal injury after 60 min DHCA. Significant neuronal cell death correlates with reduced neuroglobin expression and might reflect a limited capacity to compensate for ischemic injury. Both respiratory cell proteins may constitute attractive targets for therapeutic modulation of gene regulation, but further studies are necessary.