Assessment of microcirculatory alteration by a vascular occlusion test using near-infrared spectroscopy in pediatric cardiac surgery: effect of cardiopulmonary bypass.

OBJECTIVES: Cardiopulmonary bypass cause microcirculatory alterations. Near infrared spectroscopic measurement of tissue oxygen saturation and vascular occlusion test are novel technologies for assessing the microcirculatory function of peripheral tissue specifically in patients undergoing cardiac surgery with cardiopulmonary bypass.Our study aimed to evaluate dynamic microcirculatory function using the vascular occlusion testing during cardiac surgery in pediatric patients. METHODS: 120 pediatric patients were scheduled. Children had continuous regional oxygen saturation monitoring using near infrared spectroscopy and vascular occlusion test. Vascular occlusion test was performed five times; before induction (T1), after induction (T2), then during cardiopulmonary bypass with full flow (T3), after the termination of CPB (T4) and after sternum closure (T5). RESULTS: Basal value was the lowest at T3 and this value was significantly different among measurements (p < 0,01).Values for maximum and minimum tissue oxygen saturation were the lowest at T3 (83,4 and 52,9%).The occlusion slope varied significantly among measurements (p < 0,01).Reperfusion slopes were significantly different among measurements (p < 0,01) with a further progressive decrease in reperfusion slope with duration of cardiopulmonary bypass. CONCLUSION: Microcirculatory function can assessed using VOT with forearm Near-infrared spectroscopy derived variables during cardiopulmonary bypass in pediatric cardiac surgery. Noninvasive assessment of microcirculatory perfusion during cardiopulmonary bypass can further help evaluate and improve circulatory support techniques. TRIAL REGISTRATION: The research Project was registered at ClinicalTrials.gov (NCT06191913).

Assessment of renal function and prevalence of acute kidney injury following coronary artery bypass graft surgery and associated risk factors: A retrospective cohort study at a tertiary care hospital in Islamabad, Pakistan.

Acute kidney injury (AKI) is a sudden decline in renal function after cardiac surgery. It is characterized by a significant reduction in glomerular filtration rate, alterations in serum creatinine (S.Cr) levels, and urine output. This study aimed to retrospectively analyze a cohort of 704 patients selected using stringent inclusion and exclusion criteria. AKI was defined by an increase of 0.3 mg/dL in S.Cr levels compared to baseline. Data were collected from the hospital and analyzed using SPSS 16.0. Data analysis revealed that 22% (n = 155) of the patients developed AKI on the second post-operative day, accompanied by a substantial increase in S.Cr levels (from 1.064 ±â€…0.2504 to 1.255 ±â€…0.2673, P < .000). Age and cardiopulmonary bypass duration were identified as risk factors along with ejection fraction and days of hospital stay, contributing to the development of AKI. Early renal replacement therapy can be planned when the diagnosis of AKI is established early after surgery.

Incidence of Acute Neurological Events in Neonates and Infants Undergoing Cardiac Surgery Using a High-Hematocrit/ High-Flow Bypass Strategy.

Background: The incidence of new acute neurological injury occurring in neonates and infants during cardiac surgery utilizing cardiopulmonary bypass is reportedly 3% to 5%. In 2013, we adopted a high flow rate, and high hematocrit bypass strategy, and sought to assess the incidence of early neurological injuries associated with this strategy. Methods: Neonates and infants undergoing cardiopulmonary bypass between January 2013 and December 2019 (n = 714) comprise the study. Adverse neurological events (ANEs) were defined as any abnormality of pupils, delayed awakening, seizures, focal neurological deficits, concerns prompting neurological consultation, or any abnormality on neurological imaging in the postoperative period. Our bypass strategy included a high flow rate (150-200 mL/kg/min), without reduction of flow rates during cooling and maintaining a target hematocrit on bypass > 32% with a terminal hematocrit of > 42%. Results: Median weight at the time of the procedure was 4.6 kg (IQR 3.6-6.1 kg) with the smallest patient weighing 1.36 kg. There were 46 premature patients (6.4%). There were 149 patients (20.9%) patients who underwent deep hypothermic circulatory arrest with a median time of 26 min (IQR 21-41 min). Hospital mortality was 3.5% (24/714, 95% CI: 2.28-5.13). The incidence of neurological events as defined above was 0.84% (6/714, 95% CI: 0.31-1.82). Neurological imaging identified ischemic injury in 4 patients and intraventricular hemorrhage in 2. Conclusions: High flow/high hematocrit bypass strategy was associated with a low incidence of ANE in this vulnerable population.

Epidemiology of severe bleeding in children following cardiac surgery involving cardiopulmonary bypass: use of Bleeding Assessment Scale for critically Ill Children (BASIC).

OBJECTIVES: To describe the epidemiology of severe bleeding in the immediate post-operative period in children who undergo cardiopulmonary bypass surgery using the Bleeding Assessment Scale for critically Ill Children (BASIC). STUDY DESIGN: Retrospective cohort study in a paediatric ICU from 2015 to 2020. RESULTS: 356 children were enrolled; 59% were male with median (IQR) age 2.1 (0.5-8) years. Fifty-seven patients (16%) had severe bleeding in the first 24 hours post-operatively. Severe bleeding was observed more frequently in younger and smaller children with longer bypass and cross-clamp times (p-values <0.001), in addition to higher surgical complexity (p = 0.048). Those with severe bleeding received significantly more red blood cells, platelets, plasma, and cryoprecipitate in the paediatric ICU following surgery (all p-values <0.001). No laboratory values obtained on paediatric ICU admission were able to predict severe post-operative bleeding. Those with severe bleeding had significantly less paediatric ICU-free days (p = 0.010) and mechanical ventilation-free days (p = 0.013) as compared to those without severe bleeding. CONCLUSIONS: Applying the BASIC definition to our cohort, severe bleeding occurred in 16% of children in the first day following cardiopulmonary bypass. Severe bleeding was associated with worse clinical outcomes. Standard laboratory assays do not predict bleeding warranting further study of available laboratory tests.

Assessment of fluid balance after neonatal cardiac surgery: a description of intake/output vs. weight-based methods.

BACKGROUND: Fluid overload associates with poor outcomes after neonatal cardiac surgery, but consensus does not exist for the most clinically relevant method of measuring fluid balance (FB). While weight change-based FB (FB-W) is standard in neonatal intensive care units, weighing infants after cardiac surgery may be challenging. We aimed to identify characteristics associated with obtaining weights and to understand how intake/output-based FB (FB-IO) and FB-W compare in the early postoperative period in this population. METHODS: Observational retrospective study of 2235 neonates undergoing cardiac surgery from 22 hospitals comprising the NEonatal and Pediatric Heart and Renal Outcomes Network (NEPHRON) database. RESULTS: Forty-five percent (n = 998) of patients were weighed on postoperative day (POD) 2, varying from 2 to 98% among centers. Odds of being weighed were lower for STAT categories 4 and 5 (OR 0.72; 95% CI 0.53-0.98), cardiopulmonary bypass (0.59; 0.42-0.83), delayed sternal closure (0.27; 0.19-0.38), prophylactic peritoneal dialysis use (0.58; 0.34-0.99), and mechanical ventilation on POD 2 (0.23; 0.16-0.33). Correlation between FB-IO and FB-W was weak for every POD 1-6 and within the entire cohort (correlation coefficient 0.15; 95% CI 0.12-0.17). FB-W measured higher than paired FB-IO (mean bias 12.5%; 95% CI 11.6-13.4%) with wide 95% limits of agreement (- 15.4-40.4%). CONCLUSIONS: Weighing neonates early after cardiac surgery is uncommon, with significant practice variation among centers. Patients with increased severity of illness are less likely to be weighed. FB-W and FB-IO have weak correlation, and further study is needed to determine which cumulative FB metric most associates with adverse outcomes. A higher resolution version of the Graphical abstract is available as Supplementary information.

Predicting the risk of acute kidney injury after cardiopulmonary bypass: development and assessment of a new predictive nomogram.

BACKGROUND: Acute kidney injury (AKI) is a common and severe complication of cardiac surgery with cardiopulmonary bypass (CPB). This study aimed to establish a model to predict the probability of postoperative AKI in patients undergoing cardiac surgery with CPB. METHODS: We conducted a retrospective, multicenter study to analyze 1082 patients undergoing cardiac surgery under CPB. The least absolute shrinkage and selection operator regression model was used to optimize feature selection for the AKI model. Multivariable logistic regression analysis was applied to build a prediction model incorporating the feature selected in the previously mentioned model. Finally, we used multiple methods to evaluate the accuracy and clinical applicability of the model. RESULTS: Age, gender, hypertension, CPB duration, intraoperative 5% bicarbonate solution and red blood cell transfusion, urine volume were identified as important factors. Then, these risk factors were created into nomogram to predict the incidence of AKI after cardiac surgery under CPB. CONCLUSION: We developed a nomogram to predict the incidence of AKI after cardiac surgery. This model can be used as a reference tool for evaluating early medical intervention to prevent postoperative AKI.

Proton magnetic resonance spectroscopy assessment of neonatal brain metabolism during cardiopulmonary bypass surgery.

Here, we report on the development and performance of a robust 3-T single-voxel proton magnetic resonance spectroscopy (1 H MRS) experimental protocol and data analysis pipeline for quantifying brain metabolism during cardiopulmonary bypass (CPB) surgery in a neonatal porcine model, with the overall goal of elucidating primary mechanisms of brain injury associated with these procedures. The specific aims were to assess which metabolic processes can be reliably interrogated by 1 H MRS on a 3-T clinical scanner and to provide an initial assessment of brain metabolism during deep hypothermia cardiac arrest (DHCA) surgery and recovery. Fourteen neonatal pigs underwent CPB surgery while placed in a 3-T MRI scanner for 18, 28, and 37°C DHCA studies under hyperglycemic, euglycemic, and hypoglycemic conditions. Total imaging times, including baseline measurements, circulatory arrest (CA), and recovery averaged 3 h/animal, during which 30-40 single-voxel 1 H MRS spectra (sLASER pulse sequence, TR/TE = 2000/30 ms, 64 or 128 averages) were acquired from a 2.2-cc right midbrain voxel. 1 H MRS at 3 T was able to reliably quantify (1) anaerobic metabolism via depletion of brain glucose and the associated build-up of lactate during CA, (2) phosphocreatine (PCr) to creatine (Cr) conversion during CA and subsequent recovery upon reperfusion, (3) a robust increase in the glutamine-to-glutamate (Gln/Glu) ratio during the post-CA recovery period, and (4) a broadening of the water peak during CA. In vivo 1 H MRS at 3 T can reliably quantify subtle metabolic brain changes previously deemed challenging to interrogate, including brain glucose concentrations even under hypoglycemic conditions, ATP usage via the conversion of PCr to Cr, and differential changes in Glu and Gln. Observed metabolic changes during CPB surgery of a neonatal porcine model provide new insights into possible mechanisms for prevention of neuronal injury.

A Pharmacokinetic and Plasmin-Generation Pharmacodynamic Assessment of a Tranexamic Acid Regimen Designed for Cardiac Surgery With Cardiopulmonary Bypass.

OBJECTIVES: To examine the pharmacokinetics (PK) and pharmacodynamics of a tranexamic (TXA) regimen designed for cardiac surgery with cardiopulmonary bypass (CPB). DESIGN: A pilot study quantifying TXA concentrations, fibrinolysis markers, and a plasmin- generation (PG) assay. For comparison, PG assay was performed on pooled normal plasma (PNP) with varying TXA concentrations. SETTING: A single-center, tertiary, academic medical center. PARTICIPANTS: Twenty patients undergoing cardiac surgery with CPB for valve surgery and/or coronary artery bypass grafting. INTERVENTION: TXA 100 mg/h infusion for 5 hours starting before incision; 1 g TXA in CPB prime and 1 g TXA at CPB end prior to heparin reversal. MEASUREMENTS AND MAIN RESULTS: The PK fit a 2-compartment disposition model. TXA concentrations were above 15 mg/L in all patients during CPB through 2 hours post-TXA infusion. During and after CPB, the TXA regimen decreased the median peak PG by 60% (95% confidence interval [CI], 56%-62%). Lowest median peak PG occurred 15 minutes postprotamine. Peak median D-dimer level of 1.24 (0.95-1.71; 95% CI) mg/L occurred at 15 minutes postprotamine and baseline-adjusted ΔD dimer correlated with increased CPB time (p = 0.004) and lower TXA level (p = 0.001). The median 24-hour chest tube output was 447 (330-664; 95% CI) mL. PG assay on PNP revealed a plateau inhibition at 5 mM TXA (786 mg/L). CONCLUSIONS: This regimen, with total perioperative dose of 2.5 grams, provided TXA concentrations above 15 mg/L for all patients from CPB initiation through 2 hours post-TXA. PG was significantly inhibited (p < 0.0001) during and after CPB, with maximum inhibition measured at 15 minutes after protamine administration.

The assessment of patients undergoing cardiac surgery for Covid-19: Complications occurring during cardiopulmonary bypass.

The outbreak of the novel coronavirus pandemic (COVID-19) has resulted in dramatic changes to the conduct of surgery both from a patient management perspective and in protecting healthcare providers. The current study reports on the status of COVID-19 infections in patients presenting for cardiac surgery with cardiopulmonary bypass (CPB) on circuit complications. A tracking process for monitoring the presence of COVID-19 in adult cardiac surgery patients was integrated into a case documentation system across United States hospitals where out-sourced perfusion services were provided. Assessment included infection status, testing technique employed, surgery status and CPB complications. Records from 5612 adult patients who underwent cardiac surgery between November 1, 2020 and January 18, 2021 from 176 hospitals were reviewed. A sub-cohort of coronary artery bypass graft patients (3283) was compared using a mixed effect binary logistic regression analysis. 4297 patients had negative test results (76.6%) while 49 (0.9%) tested positive for COVID-19, and unknown or no results were reported in 693 (12.4%) and 573 (10.2%) respectively. Coagulation complications were reported at 0.2% in the negative test results group versus 4.1% in the positive test result group (p < 0.001). Oxygenator gas exchange complications were 0.2% in the negative test results group versus 2.0% in the positive test results group (p = 0.088). Coronary artery bypass graft patients with a positive test had significantly higher risk for any CPB complication (p = 0.003) [OR 10.38, CI 2.18-49.53] then negative test patients [OR 0.01, CI 0.00-0.20]. The present study has shown that patients undergoing cardiac surgery with CPB who test positive for COVID-19 have higher CPB complication rate than those who test negative.

Quick Assessment of the Lower Limit of Autoregulation by Use of Transcranial Doppler Ultrasound During Cardiac Surgery.

INTRODUCTION: Assessment of the individual safest minimal mean arterial pressure (MAP) during cardiac surgery remains empirical. The objective of this study was to evaluate the lower limit of autoregulation (LLA) within a short period (15 min). METHODS: After developing autoregulation software (OptiMAP) incorporated into transcranial Doppler ultrasound (Waki-Atys®, Lyon, France), we monitored the mean blood flow velocity (MV) and MAP. Thirty successive values of MV and MAP were automatically analysed to calculate the correlation (Mx) between the two parameters. We compared two methods of Mx sampling during a period of 15 min: Mx10s = long averaging windows (one MAP/MV pair recorded every 10 s), and Mx2s = short averaging windows (one MAP/MV pair recorded every 2 s). The LLA value calculated from the whole recording (Mx10s) was used as the reference. Autoregulation was considered impaired at an Mx value >0.35. RESULTS: Five patients were included in the study. The surgery lasted for 138 ± 32 min and cardiopulmonary bypass lasted for 72 ± 33 min. MAP and MV were recorded for 117 ± 24 min. MAP varied from 33 ± 10 to 92 ± 10 mmHg. LLA calculated from the whole recording (Mx10s) was similar to LLA calculated from the 15-min recording (Mx2s): 70 ± 2.5 versus 73 ± 3.5 mmHg. MAP remained below LLA during 48 ± 12% of the recording. During the 15-min recording, Mx10s was not able to calculate the LLA value. CONCLUSION: In cases of haemodynamic instability, decreasing the Mx sampling window seems to accurately detect LLA.

Predicting the Risk of Acute Kidney Injury in Patients After Percutaneous Coronary Intervention (PCI) or Cardiopulmonary Bypass (CPB) Surgery: Development and Assessment of a Nomogram Prediction Model.

BACKGROUND We sought to create a model that incorporated ultrasound examinations to predict the risk of acute kidney injury (AKI) after percutaneous coronary intervention (PCI) or cardiopulmonary bypass (CPB) surgery. MATERIAL AND METHODS A total of 292 patients with AKI after PCI or CPB surgery were enrolled for the study. Afterwards, treatment-related information, including data pertaining to ultrasound examination, was collected. A random forest model and multivariate logistic regression analysis were then used to establish a predictive model for the risk of AKI. Finally, the predictive quality and clinical utility of the model were assessed using calibration plots, receiver-operating characteristic curve, C-index, and decision curve analysis. RESULTS Predictive factors were screened and the model was established with a C-index of 0.955 in the overall sample set. Additionally, an area under the curve of 0.967 was obtained in the training group. Moreover, decision curve analysis also revealed that the prediction model had good clinical applicability. CONCLUSIONS The prediction model was efficient in predicting the risk of AKI by incorporating ultrasound examinations and a number of factors. Such included operation methods, age, congestive heart failure, body mass index, heart rate, white blood cell count, platelet count, hemoglobin, uric acid, and peak intensity (kidney cortex as well as kidney medulla).

Assessment of postoperative risk factors for EEG abnormalities in routine clinical management after paediatric cardiopulmonary bypass.

OBJECTIVES: The postoperative risk factors for electroencephalogram(EEG) abnormalities after paediatric cardiopulmonary bypass (CPB) remain to be identified. We investigated the characteristics of EEG abnormalities and risk factors in routine clinical management post-CPB. METHODS: EEG and cerebral oxygen saturation (ScO2) were monitored in 96 patients (aged 3 days, 37 months, median 5 months) for 72 h post-CPB. Clinical measurements included 4-hourly arterial and central venous pressure, arterial blood gases, doses of inotropic and vasoactive drugs, daily C-reactive protein (CRP) and NT-proB-type Natriuretic Peptide (NT-proBNP). Demographics, STAT categories and outcomes (duration of mechanical ventilation,CICU stay) were recorded. Un. RESULTS: Seizures occurred in 20 patients (20.8%) beginning at 0-48 hand lasting 10 min-31 h; background abnormalities occurred in 67 (69.8%) beginning at 0-8 h and lasting 4-48 h. Patients with EEG abnormalities had worse outcomes. In univariable regression, seizures positively correlated with STAT categories, CPB time, temperature, blood pressure, central venous pressure, NT-proBNP, CRP, lactate and epinephrine, negatively with ScO2 and PaCO2 (P < 0.001 for lactate and epinephrine, P < 0.1 for the remaining). The degree of background abnormalities positively correlated with STAT categories, CPB time, operative time, central venous pressure, milrinone, negatively with blood pressure (P = 0.0003-0.087); it negatively correlated with lower dose of epinephrine (P < 0.001) and positively with higher dose (P = 0.03l). In multivariable regression, seizures positively correlated with epinephrine, lactate and temperature; the background abnormality correlations remain significant except for milrinone and operative time (P < 0.001 for epinephrine, P < 0.05 for the remaining). CONCLUSIONS: Numerous perioperative risk factors are associated with EEG abnormalities post-CPB. The most significant and consistent risk factor is epinephrine.

Risk factors and outcomes of prolonged cardiopulmonary bypass time in surgery for adult congenital heart disease: a single-center study from a low-middle-income country.

BACKGROUND: Prolonged cardiopulmonary bypass time (prolonged CPBT; PCPBT) during operations for adult congenital heart disease (ACHD) may lead to worse postoperative outcomes, which could add a significant burden to hospitals in developing countries. This study aimed to identify risk factors and outcomes of PCPBT in patients undergoing operations for ACHD. METHODS: This retrospective study included all adult patients (≥18 years) who underwent cardiac surgery with cardiopulmonary bypass for their congenital heart defect from 2011-2016 at a tertiary-care private hospital in Pakistan. Prolonged CPBT was defined as CPBT>120 minutes (65th percentile). RESULTS: This study included 166 patients (53.6% males) with a mean age of 32.05±12.11 years. Comorbid disease was present in 59.0% of patients. Most patients underwent atrial septal defect repair (42.2%). A total of 58 (34.9%) of patients had a PCPBT. Postoperative complications occurred in 38.6% of patients. Multivariable analysis adjusted for age, gender and RACHS-1 Categories showed that mild preoperative left ventricular (LV) dysfunction was associated with PCPBT (OR=3.137 [95% CI: 1.003-9.818]), while obesity was found to be protective (0.346 [0.130-0.923]). PCPBT was also associated with a longer duration of ventilation (1.298 [1.005-1.676]), longer cardiac ICU stay (1.204 [1.061-1.367]) and longer hospital stay (1.120 [1.005-1.247]). CONCLUSIONS: While mild preoperative LV dysfunction was associated with PCPBT, obesity was found to be protective. Postoperatively, PCPBT was associated with longer duration of ventilation, cardiac ICU stay, and hospital stay. Operations with shorter CPBT may help minimize the occurrence and impact of these postoperative adverse outcomes especially in resource-constrained developing countries.

Risk assessment of acute kidney injury following cardiopulmonary bypass.

BACKGROUND: Acute kidney injury (AKI) is a frequent and serious complication of cardiac surgery, associated with a high incidence of morbidity and mortality. Although the RIFLE criteria serve as a prominent tool to identify patients at high risk of AKI, an optimized diagnosis model in clinical practice is desired. METHODS: Based on the SOP-criteria, 365 patients (10%) developed AKI following surgery and were subjected to RRT. In contrast, the incidence of AKI, defined according to the RIFLE criteria, was only 7% (n = 251 patients). Prominent risk factors identified by SOP were patients' sex, valve and combined valve and bypass surgery, deep hypothermia, use of intra-aortic balloon pump (IABP) and previous coronary interventions. Ischemia, reperfusion, blood loss and surgery time also served as significant risk factors for patient evaluated by SOP. RESULTS: Risk assessment by RIFLE differed in as much as most patients with normothermia and those receiving only cardiovascular bypass developed AKI. However, patients' sex and valve surgery did not serve as a risk factor. CONCLUSION: Evaluation of patients by the RIFLE versus SOP criteria yielded different results with more AKI patients detected by SOP. Based on the present data, it is concluded that patients may not prone to AKI when surgery and ischemia time will be kept short, when blood loss is mitigated to a minimum and when surgery is performed under non-hypothermic conditions.

Assessment of Energy and Protein Requirements in Relation to Nitrogen Kinetics, Nutrition, and Clinical Outcomes in Infants Receiving Early Enteral Nutrition Following Cardiopulmonary Bypass.

BACKGROUND: Nutrition therapies in children with congenital heart disease (CHD) after cardiopulmonary bypass (CPB) is crucial, but energy and protein requirements remain undefined. We assessed energy and protein requirements, with nitrogen kinetics and clinical outcomes, in infants with complex CHD following CPB. METHODS: Infants were randomized to control (1.3 g/kg/d), moderate protein (MP, 2.5 g/kg/d), or high protein (HP, 4 g/kg/d) groups. Resting energy expenditure (REE) was measured 6 hours post-CPB and then at 24-hour intervals, using indirect calorimetry to formulate energy intakes. Enteral formula feeding was initiated 6 hours post-CPB and continued for 5 days. Nitrogen balance (NB); urea nitrogen waste and nitrogen retention; serum prealbumin level; and hepatic, renal, and cardiac function were measured daily. Mid-upper arm circumference and triceps skinfold were measured preoperatively and 5 days after CPB. Adverse outcomes (bacterial infection, reintubation, and cardiac intensive care unit (CICU) stay > 8 days) were recorded. RESULTS: REE was not different across the 3 groups (P = .37). It declined from 62 ± 6 to 57 ± 7 kcal/kg/d over 5 days post-CPB (P = .02). NB and nitrogen retention became positive by day 3 in the HP group but remained negative in the other 2 groups (P = .045-.003), despite higher urea nitrogen waste in the HP group (P < .0001). The HP group had a greater increase in serum prealbumin level and anthropometric measures (P = .009-.03). Other measures were not significantly different across the 3 groups. CONCLUSIONS: In infants with complex CHD in the first 5 days post-CPB, protein and energy intakes of ≈4 g/kg/d and 60 kcal/kg/d, respectively, led to improved nutrition outcomes without increased adverse events.

Assessment of the right ventricle in donation after circulatory death hearts.

In donation after circulatory death heart transplantation, the donor heart is exposed to circulatory load. The right ventricle, due to its structure, has high compliance for volume load but is particularly vulnerable to increased pressure load. This study used a porcine model to conduct a functional assessment of the hemodynamics of the heart, with a focus on the right ventricle. Six pigs weighing 24.6 ± 1.4 kg were used. Circulatory death was induced by asphyxiation after median sternotomy. After 30 minutes in the state of global warm ischemia, the ascending aorta was clamped, followed by a 20-minute reperfusion of the heart with a 20°C blood cardioplegia solution. Systemic circulation was established by cardiopulmonary bypass after aortic cross-clamping. After initial reperfusion, the blood cardioplegia solution was replaced with blood. The blood was then rewarmed while the heart was still in a non-working state. Cardiac function was assessed twice in situ, first by the thermodilution method, and then, by the pressure-volume measurement both at preischemia and at three hours after initiation of reperfusion. The recovery rate of cardiac output was 75%. End-systolic elastance (P = .02) and pulmonary arterial elastance significantly increased (P = .03), but the ratio of arterial elastance to end-systolic elastance was preserved (P = .91) in the right ventricle. Despite a decrease in cardiac output after reperfusion from warm ischemia, the right ventricle had a potential to respond the elevated afterload. It is important that donations after circulatory death heart transplantation should be performed with attention to avoiding right ventricular distension.

Multimodal Cardiopulmonary Bypass Skills Assessment Within a High-Fidelity Simulation Environment.

BACKGROUND: A high-fidelity simulator that uses a perfused porcine heart, cannulae, and tubing has been demonstrated to be a useful training adjunct. We hypothesized that multimodal assessment of cardiopulmonary bypass (CPB) skills within this high-fidelity simulated environment could discern expert from trainee performance. METHODS: Three traditional fellows (postgraduate year 6-8) and 3 attending surgeons each performed 3 aortic cannulations. The third sequence included venous cannulation, commencement of CPB, and placement of a cardioplegia catheter and aortic cross-clamp. Performance across 20 cognitive and 21 technical domains was evaluated. Surgeon and assistant hand movements and economy of motion were assessed by electromagnetic motion sensors worn under sterile gloves. RESULTS: Analysis showed a significant difference in cognitive (6.7 ± 2.3 vs 4.6 ± 2.7, P = .03) but not technical (6.2 ± 2.5 vs 5.8 ± 2.2, P = .7) scores favoring the experts. In addition, experts showed higher efficiency by spending 64 ± 14 seconds to construct a nonpledgeted aortic purse-string suture and secure it with a Rummel, while trainees spent 82 ± 30 seconds to complete this task (P = .03). Motion analysis revealed similar path lengths between experts and trainees for cannulation and CPB but significantly shorter path lengths for experts in cross-clamp (47.5 ± 15.5 m vs 91.9 ± 20.3 m, P = .04). CONCLUSIONS: Multimodal assessment using cognitive, technical, and motion analysis of basic CPB tasks using a high-fidelity simulation environment is a valid system to measure performance and discriminate experts from trainees. This construct may allow for development of "competence thresholds" with important implications for training and certification in cardiothoracic surgery.

Effect of comorbid neuropsychiatric disorders on children and adolescents undergoing surgery for moderate and severe congenital heart disease.

BACKGROUND: Children and adolescents with congenital heart disease (CHD) are at an increased risk of neuropsychiatric disorders (NPDs). The purpose of this study is to determine how a comorbid NPD affects hospital outcomes and costs for CHD patients undergoing cardiac surgery. METHODS: Retrospective review of the 2000-2012 Healthcare Cost and Utilization Project Kids' Inpatient Databases for admissions 10 to 21 years old with an ICD-9 code for moderate or severe CHD and a procedure code for cardiopulmonary bypass as a marker for cardiac surgery; admissions with syndromes that could be associated with NPD were excluded. Demographics, hospital outcomes, and charges were compared between admissions with and without NPD ICD-9 codes using analysis of variance, independent samples Kruskal-Wallis, and χ2 , as appropriate. RESULTS: There were 4768 admissions with CHD and cardiac surgery: 4285 (90%) with no NPD, 93 (2%) with cognitive deficits, 390 (8%) with mood/behavior deficits. Patients with NPD had a longer length of stay and higher mean charges (P < .001 for both). Patients with mood/behavior deficits were older and patients with cognitive deficits were more likely female (P < .001 for both). CONCLUSIONS: Children and adolescents with moderate or severe CHD and NPD who undergo cardiac surgery incur longer hospital stays and higher charges. Recognizing and addressing the underlying NPDs may be important to improve postoperative progression for children and adolescents with CHD hospitalized for cardiac surgery.

Renal Near-Infrared Spectroscopy for Assessment of Renal Oxygenation in Adults Undergoing Cardiac Surgery: A Method Validation Study.

OBJECTIVE: To investigate the correlation between invasively measured renal venous oxygen saturation (SrvO2) and tissue oxygenation (rSO2) measured with near-infrared spectroscopy (NIRS) in adult patients undergoing cardiac surgery. DESIGN: Prospective observational study. SETTING: Single cardiac surgery center at a university hospital. PARTICIPANTS: Thirteen adult patients with skin- to- kidney distance ≤4 cm undergoing open cardiac surgery with cardiopulmonary bypass (CPB). INTERVENTIONS: All patients received renal vein catheters for invasive measurement of SrvO2, and NIRS electrodes for assessment of renal rSO2 were placed over the kidney using ultrasound guidance. Measurements were made before CPB, during CPB at 3 different flow rates (2.4, 2.7, and 3.0 L/min/m2), and after CPB. MEASUREMENTS AND MAIN RESULTS: Repeated- measures correlation analyses and Bland-Altman plots were used to study the correlation and agreement between rSO2 and SrvO2. For all measurement points, renal rSO2 correlated with SrvO2 (rrm = 0.61, p < 0.001), and the mean difference (bias) between rSO2 and SrvO2 was -2.71 ± 7.22 (p = 0.002), with an error of 17.6%. When measurements during CPB and before and after CPB were studied separately, rSO2 and SrvO2 were correlated (rrm = 0.51, p < 0.007 and rrm = 0.73, p < 0.001, respectively). During CPB, renal rSO2 predicted SrvO2 with a bias of -3.41 ± 7.76 (p = 0.009) and an error of 18.8%. Before and after CPB, the mean difference was -1.93 ± 6.60 (p = 0.092), with an error of 16.2%. CONCLUSIONS: Renal rSO2 is correlated to and predicts SrvO2 with a small bias and acceptable agreement. Further studies are needed before renal NIRS can be used as a surrogate marker of renal oxygenation in clinical practice.