Digital Holographic Microscopy for Label-Free Detection of Leukocyte Alternations Associated with Perioperative Inflammation after Cardiac Surgery

In a prospective observational pilot study on patients undergoing elective cardiac surgery with cardiopulmonary bypass, we evaluated label-free quantitative phase imaging (QPI) with digital holographic microscopy (DHM) to describe perioperative inflammation by changes in biophysical cell properties of lymphocytes and monocytes. Blood samples from 25 patients were investigated prior to cardiac surgery and postoperatively at day 1, 3 and 6. Biophysical and morphological cell parameters accessible with DHM, such as cell volume, refractive index, dry mass, and cell shape related form factor, were acquired and compared to common flow cytometric blood cell markers of inflammation and selected routine laboratory parameters. In all examined patients, cardiac surgery induced an acute inflammatory response as indicated by changes in routine laboratory parameters and flow cytometric cell markers. DHM results were associated with routine laboratory and flow cytometric data and correlated with complications in the postoperative course. In a subgroup analysis, patients were classified according to the inflammation related C-reactive protein (CRP) level, treatment with epinephrine and the occurrence of postoperative complications. Patients with regular courses, without epinephrine treatment and with low CRP values showed a postoperative lymphocyte volume increase. In contrast, the group of patients with increased CRP levels indicated an even further enlarged lymphocyte volume, while for the groups of epinephrine treated patients and patients with complicative courses, no postoperative lymphocyte volume changes were detected. In summary, the study demonstrates the capability of DHM to describe biophysical cell parameters of perioperative lymphocytes and monocytes changes in cardiac surgery patients. The pattern of correlations between biophysical DHM data and laboratory parameters, flow cytometric cell markers, and the postoperative course exemplify DHM as a promising diagnostic tool for a characterization of inflammatory processes and course of disease.

Risk factors for postoperative delirium after cardiac surgical procedures with cardioplegic arrest

OBJECTIVES

The pathophysiology of delirium after cardiac surgery is complex. The present study aims to determine perioperative risk factors and construct a scoring system for postoperative delirium based on the type of surgery.

METHODS

Three hundred patients undergoing coronary artery bypass grafting (CABG; n = 150) or valve and/or aortic surgery ± CABG (n = 150) were retrospectively evaluated.

RESULTS

The incidence of delirium (32%) was similar in subgroups (28.7% and 33.33%, P = 0.384). Delirium patients were older [71.3 (standard deviation: 8.5) vs 66.6 (standard deviation: 9.5), P < 0.001; 70.0 (standard deviation: 9.6) vs 62.5 (standard deviation: 12.6), P < 0.001] and required more packed red blood cell units [2.1 (standard deviation: 2.1) vs 4.2 (standard deviation: 4.0), P < 0.001; 2.4 (standard deviation: 3.3) vs 5.4 (standard deviation: 5.9), P < 0.001] and fresh frozen plasma units [6.1 (standard deviation: 2.9) vs. 8.0 (standard deviation: 4.2), P < 0.001; 6.3 (standard deviation: 3.4) vs 10.8 (standard deviation: 7.2), P < 0.001] in CABG and valve/aortic subgroups, respectively. Delirium was associated with longer operation time [298.3 (standard deviation: 98.4) vs 250.6 (standard deviation: 67.8) min, P < 0.001], cardiopulmonary bypass (CPB) time [171.5 (standard deviation: 54.9) vs 140.98 (standard deviation: 45.8) min, P < 0.001] and cardiac arrest time [112 (standard deviation: 35.9) vs 91.9 (standard deviation: 28.6), P < 0.001] only in the valve/aortic group (versus non-delirium). Multivariate regression analysis identified an association between delirium and age [odds ratio: 1.056 (95% confidence interval: 1.002-1.113), P = 0.041], CPB time [odds ratio: 1.1014 (95% confidence interval: 1.004-1.025), P = 0.007], fresh frozen plasma transfusion [odds ratio: 1.127 (95% confidence interval: 1.006-1.262), P = 0.039] and atrial fibrillation [odds ratio: 4.801 (95% confidence interval: 1.844-12.502), P < 0.001] after valve/aortic surgery (area under the curve 0.835, P < 0.001) and between delirium and age [odds ratio: 1.089 (95% confidence interval: 1.023-1.160), P = 0.007] and ventilation time [odds ratio: 1.068 (95% confidence interval: 1.026-1.113), P = 0.001] after isolated CABG (area under the curve 0.798, P < 0.001). The cross-validation of the results by k-fold logistic regression revealed for the entire patient cohort an overall average accuracy of the prediction model of 0.764, with a false-positive rate of 0.052 and a false-negative rate of 0.18.

CONCLUSIONS

Age, CPB time, ventilation, transfusion and atrial fibrillation are differently associated with delirium depending on the operative characteristics. Optimization of intraoperative parameters and use of risk calculators may enable early institution of pharmacotherapy and improve overall outcome after cardiac surgery.

Prospective evaluation of novel biomarkers of acute kidney injury in dogs following cardiac surgery under cardiopulmonary bypass

OBJECTIVE

To assess the occurrence of acute kidney injury (AKI) in dogs undergoing cardiac surgery under cardiopulmonary bypass (CPB) and explore associations between traditional and novel serum and urinary biomarkers.

DESIGN

Prospective cohort study conducted between July 2018 and April 2019.

SETTING

University teaching hospital.

ANIMALS

Nineteen dogs undergoing cardiac surgery under CPB with preoperative serum creatinine <140 μmol/L (<1.6 mg/dl).

INTERVENTIONS

Blood and urine samples were obtained at 4 time points: preoperatively following general anesthesia induction, immediately postoperatively, and 2 and 4 days postoperatively (T₁ , T₂ , T₃ , and T₄ ). AKI was defined as an increase in serum creatinine ≥26.4 μmol/L (≥0.3 mg/dl) above baseline within 48 hours. Serum creatinine, C-reactive protein (CRP), symmetric dimethylarginine (SDMA), inosine, beta-aminoisobutyric acid (BAIB), urinary clusterin (uClus), and urinary cystatin B (uCysB) were measured. Data were log-transformed (log₁₀ ) when appropriate and assessed using linear mixed-effects models.

MEASUREMENTS AND MAIN RESULTS

AKI occurred in 3 of 19 dogs (15.8%, 95% confidence interval: 0.047-0.384). Inosine increased at T₂ (adjusted mean ± standard error: 53 ± 5.6) in all dogs, and then gradually decreased. Log₁₀ uCysB increased at T₂ (2.3 ± 0.1) in all dogs and remained high. Log₁₀ CRP and log₁₀ uClus increased significantly at T₃ (1.9 ± 0.1 and 3.6 ± 0.1, respectively) in all dogs and remained increased. There was a significant positive association between serum creatinine and SDMA (P < 0.001, estimate ± standard error: 0.06 ± 0.00), between log₁₀ CRP and log₁₀ uClus (P < 0.001, 0.35 ± 0.08), between SDMA and creatinine as well as between SDMA and BAIB (P < 0.001, 11.1 ± 0.83 and P < 0.001, 1.06 ± 0.22, respectively) for all dogs at all time points.

CONCLUSIONS

Inosine and uCysB concentrations changed in all dogs immediately following a surgery under CPB and may indicate tubular injury. Further studies are required to ascertain the usefulness of those biomarkers in early detection of AKI.

Central, peripheral ECMO or CPB? Comparsion between circulatory support methods used during lung transplantation

BACKGROUND

Chronic obstructive pulmonary disease, cystic fibrosis and usual interstitial pneumonia are three most common indications for lung transplantation (LuTx) in Poland. As a result of irreversible destruction of pulmonary parenchyma and extended respiratory insufficiency that appear afterwards, it is crucial to estimate the reserve of gas exchange in each lung before and during surgery. Altering conditions of gas exchange require adaptation in circulatory system as well. In some of the cases the use of extracorporeal life support appears to be necessary to undergo the transplantation successfully. Cardiopulmonary bypass (CPB) or extracorporeal membrane oxygenation (ECMO) used during operation allow to replace the function of heart and lung, but they are also related to complications in the form of acute kidney failure, bleeding, heart arrhythmias or thromboembolic complications.

METHODS

We reviewed 77 LuTx from 2009 to 2020 performed at the Department of Thoracic Surgery and Transplantation. 40/77 (51%) patients required intraoperative extracorporeal assistance: 8 required CBP and 32 required ECMO. In the ECMO group 14/32 (44%) patients had peripheral cannulation and 18/32 (56%) had central one. We have calculated the survival rates and reviewed postoperative complications after lung transplantations. Cumulative Kaplan-Meier survival curves were calculated. Differences between the groups were evaluated by the Chi- square analysis for discontinuous variables and t-test for continuous variables.

RESULTS

The use of intraoperative central extracorporeal membrane oxygenator was associated with increased survival rates comparing to patients without external support (30-days, 1-year, 3-years, 5-years rates: 78%, 66%, 66%, 66% vs 83%, 65%, 59%, 44% respectively). Furthermore, survival was enhanced comparing to peripheral ECMO or cardiopulmonary bypass as well (50%, 41%, 41%, 33%; 75%, 50%, 50%, 38% respectively). Acute kidney injury and thromboembolic complications occurred statistically more often in case of patients that underwent lung transplantation with support devices (p = 0.005, p = 0.02 respectively). Frequency of other complications was comparable among groups.

CONCLUSIONS

The use of central extracorporeal membrane oxygenation should be favorized over peripheral cannulation or cardiopulmonary bypass. CPB should be no longer used during LuTx. Trial registration Not applicable.

Current Application of NIRS and CPB Initiation Times in German Cardiac Surgery Centers: A Survey

Near-infrared spectroscopy (NIRS) has been widely used in cardiac surgery to monitor cerebral oxygen supply. The initiation and perioperative management of cardiopulmonary bypass (CPB) constitute critical events in modifying the normal physiology of adequate blood and oxygen supply to the brain. First, little is known about how frequent NIRS is really used. Second, there are varying practices on how to initiate CPB. We therefore conducted a survey in Germany to get an idea of NIRS usage in cardiac surgery for the duration of initiation of CPB protocols. A web-based e-mail survey using commercial SurveyMonkey^® (SurveyMonkey, San Mateo, CA) software was conducted in August 2017 including all German cardiac surgery centers. About 75% of the perfusion departments do not use NIRS as a standard monitoring device. It is usually reserved for clinical scenarios where cerebral perfusion might be impaired such as aortic arch surgery or carotid artery stenosis. Only one-third of the departments use a standardized duration of initiation of CPB despite a common belief of potential harm with fast initiation. The usual applied time to initiate CPB ranges from 30 to 120 seconds. Our survey revealed that the NIRS technology is only used in specific types of cardiac surgery to this date. In addition, there is a clear need for scientific studies on how to initiate CPB in the best way for the patient.

Transesophageal echocardiography probe induced recurrent VF in a child with severe RV dysfunction: Report of a rare case

The safety of transesophageal echocardiography (TEE) probes has been documented in pediatric patients (neonates, infants, and small children even < 2.5 kg). The overall safety profile of TEE probe is quite favorable with a reported incidence of complications of 1%-3%. However, insertion of the TEE probe can induce vagal and sympathetic reflexes such as hypertension or hypotension, nonsustained ventricular and supraventricular tachyarrhythmias, or bradyarrhythmias (third degree heart block), and even angina and myocardial infarction. We hereby document a repeated intraoperative ventricular fibrillation precipitated by TEE probe in a 2-year-old, 10 kg pediatric patient diagnosed with ostium secundum-atrial septal defect, supravalvular pulmonary stenosis, and severe right ventricular dysfunction. The international review board approval or waiver and clinical trial registrations are not applicable for this case report publication.

Vasoplegic syndrome after cardiovascular surgery: A review of pathophysiology and outcome-oriented therapeutic management

BACKGROUND

Vasoplegic syndrome (VPS) is defined as systemic hypotension due to profound vasodilatation and loss of systemic vascular resistance (SVR), despite normal or increased cardiac index, and characterized by inadequate response to standard doses of vasopressors, and increased morbidity and mortality. It occurs in 9%-44% of cardiac surgery patients after cardiopulmonary bypass (CPB). The underlying pathophysiology following CPB consists of resistance to vasopressors (inactivation of Ca²⁺ voltage gated channels) on the one hand and excessive activation of vasodilators (SIRS, iNOS, and low AVP) on the other. Use of angiotensin-converting enzyme inhibitor (ACE-I), calcium channel blockers, amiodarone, heparin, low cardiac reserve (EF < 35%), symptomatic congestive heart failure, and diabetes mellitus are the perioperative risk factors for VPS after cardiac surgery in adults. Till date, there is no consensus about the outcome-oriented therapeutic management of VPS. Vasopressors such as norepinephrine (NE; 0.025-0.2 µg/kg/min) and vasopressin (0.06 U/min or 6 U/h median dose) are the first choice for the treatment. The adjuvant therapy (hydrocortisone, calcium, vitamin C, and thiamine) and rescue therapy (methylene blue [MB] and hydroxocobalamin) are also considered when perfusion goals (meanarterial pressure [MAP] > 60-70 mmHg) are not achieved with nor-epinephrine and/or vasopressin.

AIMS

The aims of this systematic review are to collect all the clinically relevant data to describe the VPS, its potential risk factors, pathophysiology after CPB, and to assess the efficacy, safety, and outcome of the therapeutic management with catecholamine and non-catecholamine vasopressors employed for refractory vasoplegia after cardiac surgery. Also, to elucidate the current and practical approach for management of VPS after cardiac surgery.

MATERIAL AND METHODS

"PubMed," "Google," and "Medline" weresearched, and over 150 recent relevant articles including RCTs, clinical studies, meta-analysis, reviews, case reports, case series and Cochrane data were analyzed for this systematic review. The filter was applied specificallyusing key words like VPS after cardiac surgery, perioperative VPS following CPB, morbidity, and mortality in VPS after cardiac surgery, vasopressors for VPS that improve outcomes, VPS after valve surgery, VPS after CABG surgery, VPS following complex congenital cardiac anomalies corrective surgery, rescue therapy for VPS, adjuvant therapy for VPS, definition of VPS, outcome in VPS after cardiac surgery, etiopathology of VPS following CPB. This review did not require any ethical approval or consent from the patients.

RESULTS

Despite the recent advances in therapy, the mortality remains as high as 30%-50%. NE has been recommended the most frequent used vasopressor for VPS. It restores and maintain the MAP and provides the outcome benefits. Vasopressin rescue therapy is an alternative approach, if catecholamines and fluid infusions fail to improve hemodynamics. It effectively increases vascular tone and lowers CO, and significantly decreases the 30 days mortality. Hence, suggested a first-line vasopressor agent in postcardiac surgery VPS. Terlipressin (1.3μg/kg/h), a longer acting and more specific vasoconstrictor prevents the development of VPS after CPB in patients treated with ACE-I. MB significantly reduces morbidity and mortality of VPS. The Preoperative MB (1%, 2mg/kg/30min, 1h before surgery) administration in high risk (on ACE-I) patients for VPS undergoing CABG surgery, provides 100% protection against VPS, and early of MB significantly reduces operative mortality, and recommended as a rescue therapy for VPS. Hydroxocobalamin (5 g) has been recommended as a rescue agent in VPS refractory to multiple vasopressors. A combination of ascorbic acid (6 g), hydrocortisone (200 mg/day), and thiamine (400 mg/day) as an adjuvant therapy significantly reduces the vasopressors requirement, and provides mortality and morbidity benefits.

CONCLUSION

Currently, the VPS is frequently encountered (9%-40%) in cardiac surgical patients with predisposing patient-specific risk factors and combined with inflammatory response to CPB. Multidrug therapy (NE, MB, AVP, ATII, terlipressin, hydroxocobalamin) targeting multiple receptor systems is recommended in refractory VPS. A combination of high dosage of ascorbic acid, hydrocortisone and thiamine has been used successfully as adjunctive therapyto restore the MAP. We also advocate for the early use of multiagent vasopressors therapy and catecholamine sparing adjunctive agents to restore the systemic perfusion pressure with a goal of preventing the progressive refractory VPS.

Perioperative circulatory support for lung transplantation

OBJECTIVE

Extracorporeal membrane oxygenation (ECMO) has recently replaced cardiopulmonary bypass (CPB) as the preferred option for providing circulatory support during lung transplantation. This review aimed to summarize the previous data and to address the relative use of ECMO and CPB during lung transplantation.

METHODS

The database was searched in PubMed (Medline) using the following keywords: lung transplantation, extracorporeal membrane oxygenation, and cardiopulmonary bypass, for all relevant reports which were written in English and were published between 2000 and 2020.

REVIEW

Several reports have revealed that intraoperative use of ECMO is associated with lower blood product transfusion requirements, shorter ventilator support, and shorter length of hospital stay. During recent years, preoperative ECMO has also been used with favorable outcomes as a bridge to lung transplantation in critically ill patients.

CONCLUSIONS

The use of ECMO during lung transplantation seems to reduce postoperative complications and improve short-term outcomes, relative to CPB. However, additional data should be collected through large multicenter randomized controlled trials. Furthermore, preoperative ECMO as a bridge to lung transplantation appears to provide favorable outcomes, although additional data are also needed from experienced transplant centers.

Independent Predictors of Postoperative Stroke With Cardiopulmonary Bypass

OBJECTIVE

To assess predictive factors of postoperative stroke in cardiac surgery using cardiopulmonary bypass (CPB).

DESIGN

This study was a retrospective observational study.

SETTING

This study was conducted at a single institution (Liverpool Hospital, NSW, Australia).

PARTICIPANTS

All patients with CPB treated surgically at Liverpool Hospital, NSW, between January 2016 and December 2018 INTERVENTIONS: Patients underwent cardiac surgery with CPB.

MEASUREMENTS AND MAIN RESULTS

The primary outcome was cerebrovascular accident, or stroke. Univariate and multivariate analyses via Firth's logistic regression with regard to stroke were performed. The study comprised 1,092 patients over a three-year period. In this cohort, the stroke rate was 3.1%. Via univariate analysis of factors in relation to stroke post-CPB, recent or past stroke (odds ratio [OR] 5.43 v 2.32), diabetes mellitus (OR 1.92), dialysis dependence (OR 5.67), elective procedures (OR 0.34), aortic procedures (OR 4.02), bypass and cross-clamp times (OR 1.02 and 1.04), postoperative atrial fibrillation (OR 2.28), and hypoperfusion times all reached the significance level of p ≤ 0.1 to be included in the multivariate analysis. Multivariate analysis to find independent factors in relation to stroke yielded diabetes mellitus (OR 2.49; p = 0.025), dialysis dependence (OR 3.82; p = 0.03), aortic procedures (OR 3.93; p = 0.014), and elective procedures (OR 0.24; p = 0.026) as independently predictive or protective with regard to postoperative stroke.

CONCLUSIONS

Independent predictors of stroke in this single center cohort included dialysis dependence, diabetes, and aortic procedures. Elective procedures were shown to be an independent protective factor.

Manual Carotid Compression is a Viable Alternative for Reduction of Cerebral Microemboli

BACKGROUND

Stroke is a devastating complication of cardiovascular surgeries, and the risk is particularly high for those requiring cardiopulmonary bypass (CPB). Embolic particles generated during the unclamping of the aortic cross-clamp may enter the cerebral circulation, lodging in small vessels. External manual compression of the carotid arteries is a non-invasive technique that has been proposed for cerebral protection during CPB procedures but is not widely deployed.

METHODS

The aim of this study is to assess the potential for cerebral emboli reduction with carotid compression using an in vitro model. Experiments were performed with a glass aortic arch model in a mock cardiovascular circuit. Small fluorescent particles were released into the circulation with and without carotid compression, and the particles visualized in the aortic midplane. The number of particles in the aorta and arch branch vessels were counted from the images before, during and following the release of carotid compression for durations of 10, 15 and 20 s. A gamma variate function was fit to the data to describe the bolus dynamics.

RESULTS

Carotid compression for 10 s reduces the number of embolic articles entering the carotid arteries by over 75%. A compression duration of 15-20 s does not result in greater particle reduction than one of 10 s.

CONCLUSION

Brief compression of the common carotid arteries during cardiovascular interventions has the potential to dramatically reduce the number of cerebral emboli and should be investigated further.

First Sprayable Double-Stranded RNA-Based Biopesticide Product Targets Proteasome Subunit Beta Type-5 in Colorado Potato Beetle (Leptinotarsa decemlineata)

Colorado potato beetle (CPB, Leptinotarsa decemlineata) is a major pest of potato and other solanaceous vegetables in the Northern Hemisphere. The insect feeds on leaves and can completely defoliate crops. Because of the repeated use of single insecticide classes without rotating active ingredients, many chemicals are no longer effective in controlling CPB. Ledprona is a sprayable double-stranded RNA biopesticide with a new mode of action that triggers the RNA interference pathway. Laboratory assays with second instar larvae fed Ledprona showed a dose-response where 25×10^-6g/L of dsPSMB5 caused 90% mortality after 6days of initial exposure. We also showed that exposure to Ledprona for 6h caused larval mortality and decreased target messenger RNA (mRNA) expression. Decrease in PSMB5 protein levels was observed after 48h of larval exposure to Ledprona. Both PSMB5 mRNA and protein levels did not recover over time. Ledprona efficacy was demonstrated in a whole plant greenhouse trial and performed similarly to spinosad. Ledprona, currently pending registration at EPA, represents a new biopesticide class integrated pest management and insecticide resistance management programs directed against CPB.

Biomarkers as predictors of renal damage in neonates undergoing cardiac surgery

BACKGROUND

Acute Kidney Injury is a complication in children with heart disease undergoing cardiac surgery with cardiopulmonary bypass. The aim of this study is to describe the behavior of KIM-1 (Kidney Injury Molecule) and NGAL (Neutrophil Gelatinase Associated Lipocalin) as early predictors of renal damage, comparing them with serum creatinine and creatinine clearance, in neonates undergoing cardiac surgery.

METHODS

Twenty-one (21) neonates, under 4 kg, with complex congenital heart diseases, RACHS-1 > 3, without preoperative renal failure, were studied. Serum creatinine and creatinine clearance were measured preoperatively and at 24, 48, 72, 96 hours postoperatively. Urinary samples of KIM-1(pg/ml) and NGAL (ng/ml) were collected after induction of anesthesia at 24 and 48 hours post-operatively.

RESULTS

nRIFLE criteria were used to divide cohorts in "NO AKI" (12 patients) and "AKI" (nine patients). In the AKI group, serum creatinine increased significantly and creatinine clearance decreased significantly at 24, 48, and 72 hours compared with their respective baseline values. There was no difference in KIM-1 and NGAL values between patients who developed AKI and those who did not at any measured time.

CONCLUSIONS

The deterioration of renal function continues to be one of the most frequent complications in this population. In our study, biomarkers did not show any correlation with the appearance of AKI. It remains to be seen whether this behavior of the biomarkers is linked with the non-consistent release of these types of molecules in immature kidneys. It is likely that a larger panel of biomarkers together with other glomerular filtration rate assessment methods will provide more information about AKI diagnosis.

Survey of the Routine Practice Limits for Physiologic and Technical Parameters Managed by Clinical Perfusionists during Adult Cardiopulmonary Bypass

Cardiopulmonary bypass (CPB) is a highly technical clinical discipline with a recognized variability in practice. Professional standards and guidelines documents help direct clinical practice and reduce variability, but these guidelines are necessarily vague and fall short of providing specific objective recommendations of clinical practice metrics. If clinical practice metrics were known, they would be informative when writing departmental policy manuals, structuring quality improvement initiatives, describing product R&D specifications, and designing educational assessment rubrics. Therefore, to address this gap, we conducted a national survey of clinical practice with the purpose of producing a benchmark of the typical variability of specific technical parameters that are commonly managed during adult CPB procedures. A pool of expert clinical perfusionists collaborated to compile a data set of normal ranges for 41 individual physiologic and technical parameters (pressures, flows, saturation, times, solutions, and temperatures) that are commonly managed during adult CPB procedures. Results were collected using an online survey application. Respondent demographics and measures of central tendency with descriptive quartile statistics and confidence intervals for each parameter are presented. Of the 335 people who participated in the survey, 315 met the inclusion criteria. The geographic demographics of the respondents were representative of the American Board of Cardiovascular Perfusion's distribution of certified clinical perfusionists. Of the 41 parameters investigated, there were 13 hemodynamic parameters, 13 normal flow rates and technical circuit parameters, 10 blood gasses and hematocrit parameters, and five parameters of patient temperatures. The data presented here are informative and provide a consensus-based objective assessment of the standard practice for adult CPB as reported by practicing clinical perfusionists. Based on these survey data, we have identified the typical clinical limits for the 41 parameters that are managed during adult CPB. This information may be incorporated into guiding documents to support the work of clinicians, researchers, and educators.

Inhibitor of apoptosis is an effective target gene for RNAi-mediated control of Colorado potato beetle, Leptinotarsa decemlineata

The Colorado potato beetle (CPB; Leptinotarsa decemlineata) is one of the most notorious and difficult to control pests of potato and other solanaceous crops in North America. This insect has evolved a remarkable ability to detoxify both plant and synthetic toxins, allowing it to feed on solanaceous plants containing toxic alkaloids and to develop resistance to synthetic chemicals used for its control. RNA interference (RNAi) is a natural mechanism that evolved as an immune response to double-stranded RNA (dsRNA) viruses where dsRNA triggers silencing of target gene expression. RNAi is being developed as a method to control CPB. Here, we evaluated four CPB-specific genes to identify targets for RNAi-mediated control of this insect. Out of the four dsRNAs evaluated in CPB larvae and adults, dsIAP (dsRNA targeting inhibitor of apoptosis, iap gene) performed better than dsActin, dsHSP70, and dsDynamin in inducing larval mortality. However, in adults, the mortality induced by dsActin is significantly higher than the mortality induced by dsIAP, dsHSP70, and dsDynamin. Interestingly, a combination of dsIAP and dsActin performed better than either dsIAP or dsActin alone by inducing feeding inhibition in 24 hr and mortality in 48 hr in larvae. When the dsIAP and dsActin were expressed in the Escherichia coli HT115 strain and applied as a heat-killed bacterial spray on potato plants, it protected the plants from CPB damage. These studies show that the combination of dsIAP and dsActin shows promise as an insecticide to control CPB.

Younger age is associated with greater early neurocognitive decline postcardiopulmonary bypass

Objective

To examine the effect of aging on postoperative neurocognitive decline (NCD) in cardiac surgery patients.

Methods

Patients undergoing coronary artery bypass graft or open aortic valve replacement were administered the Repeatable Battery for the Assessment of Neuropsychological Status at preoperative, postoperative day (POD) 4, and 1 month. Blood samples were collected at preoperative, 6 hours postoperative, and POD 4. Plasma interleukin (IL)-6, tumor necrosis factor-α, and C-reactive protein (CRP) levels were quantified. Quality of life was measured with the 12-Item Short Form Health Survey. Data were analyzed using paired ratio and unpaired t tests with Welch's correction, and linear regression for cytokine levels.

Results

NCD occurred in 15 patients (N = 33, 45.5%). Dichotomized at age extremes (<60 years; ≥75 years), youngest patients had greater preoperative scores (P = .02) with lower scores by POD 4 (P = .03). There was no NCD in the oldest patients, and scores were not different between age groups on POD 4 (P = .08). Regression at 1 month showed NCD scores again declined by age (n = 15), with younger scores returning toward baseline (P = .008). Regression analyses showed decline by age at 6 hours postoperative and POD 4 in plasma CRP levels (P = .05 6 hours, P = .02 POD 4). Dichotomizing IL-6 levels by age (<70 years, ≥70 years) demonstrated that levels were greater in younger versus older patients at 6 hours postoperative (P = .03), but not on POD 4.

Conclusions

Younger patients tend to have better cognitive scores before surgery but scores at POD 4 are similar to those of older patients, with this trend disappearing at 1 month. IL-6 and CRP upregulation is greater in younger patients, suggesting that a robust perioperative inflammatory response may be associated with reduction in neurocognitive function, and this may be greater in younger versus older patients.

Autologous Patch Angioplasty of a Giant Right Coronary Artery Aneurysm and Coronary Stenosis in Kawasaki Disease

We describe our management of a 2-year-old patient with Kawasaki disease with a giant proximal right coronary artery (RCA) aneurysm and a >99% RCA ostial stenosis. After median sternotomy and cardioplegic arrest of the heart, we opened the aorta and cut into the RCA ostium past the stenosis and giant aneurysm. The RCA was reconstructed with an autologous pericardial patch. Cross-clamp and cardiopulmonary bypass times of 84 minutes and 114 minutes, respectively, were required. Our approach avoids mammary harvesting and grafting in such small patients while successfully treating ischemia and hopefully prevents further aneurysmal dilation over time.

Release of active peptidylarginine deiminase into the circulation during acute inflammation induced by coronary artery bypass surgery

Purpose: Peptidylarginine deiminase (PAD) catalyzes citrullination, a post-translational modification that can alter structure, function and antigenicity of proteins. Citrullination in the lungs due to smoking is believed to initiate an anti-citrulline immune response in rheumatoid arthritis. Citrullination in other inflamed organs has also been demonstrated, but it is not known whether smoking or inflammatory processes in general result in release of relevant amounts of PAD into the circulation with potential to cause citrullination of proteins at various anatomical sites. Coronary artery bypass grafting (CABG) using cardiopulmonary bypass (CPB) induces an acute systemic inflammation response. In the present study, we investigate whether smoking or acute systemic inflammation causes release of PAD into the circulation.

Patients and methods: This study included 36 patients with coronary heart disease (16 smokers and 20 non-smokers) undergoing CABG surgery with CPB. Circulating levels of PAD2 and PAD4, PAD activity, the neutrophil activation markers MPO, MMP-9 and lipocalin-2, the cytokines IL-6 and IL-10, and the chemokine CXCL8 were measured 2 hrs preoperatively and 2 hrs postoperatively.

Results: At baseline, serum PAD2 and PAD4 concentration did not differ between smokers and non-smokers. However, serum from non-smokers contained higher PAD activity than serum from smokers. Circulating PAD2 levels and PAD activity increased markedly in both groups after surgery, as did all neutrophil activation markers, cytokines and chemokine. PAD2 levels correlated with neutrophil activation markers, but not with cytokine and chemokine levels.

Conclusion: Blood levels of PAD2 did not differ significantly between smokers and non-smokers, but smokers had decreased PAD activity in the circulation. PAD2 levels and PAD activity increased in blood during inflammation induced by CABG with CPB. This suggests that acute inflammation, ischemia or reperfusion, or a combination of these, leads to systemic spreading of enzymatically active PAD, which may affect protein function and induce generation of citrullinated self-antigens.

Air removal capacity of two different minimal invasive ECC systems: an in vitro comparison

Minimally invasive extracorporeal circulation systems are developed to decrease the deleterious effects of cardiopulmonary bypass. For instance, prime volume and foreign surface area are decreased in these systems. However, because of the lack of a venous reservoir in minimized systems, air handling properties of these minimally invasive extracorporeal circulation systems may be decreased as compared to conventional cardiopulmonary bypass systems. The aim of this in vitro study is to compare the air handling properties of two complete minimized cardiopulmonary bypass systems of two manufacturers, of which one system is provided with the air purge control. In an in vitro study, two minimally invasive extracorporeal circulation systems, Inspire Min.I manufactured by Sorin Group Italia, Mirandola, Italy (LivaNova, London, United Kingdom) and minimized extracorporeal circulation manufactured by Maquet, Rastatt, Germany (Getinge, Germany), were challenged with two types of air challenges; a bolus air challenge and a gaseous microemboli challenge. The air removal characteristics of the venous bubble traps and of the complete minimally invasive extracorporeal circulation systems were assessed by measuring the gaseous microemboli volume and number downstream of the venous bubble traps in the arterial line with a bubble counter. No significant differences were observed in air reduction between the venous bubble traps of Getinge (venous bubble traps) and LivaNova (Inspire venous bubble traps 8 in conjunction with the air purge control). Similarly, no significant differences were observed in volume and number of gaseous microemboli in the arterial line of both complete minimally invasive extracorporeal circulation systems. However, the gaseous microemboli load of the Inspire Min.I system was marginally lower after both the bolus air and the gaseous microemboli challenges. Both minimally invasive extracorporeal circulation systems assessed in this study, the LivaNova Inspire Min.I and the Getinge minimized extracorporeal circulation, showed comparable air removal properties, after both bolus and gaseous microemboli air challenges. Besides, air purge control automatic air removal system provided with the LivaNova Inspire Min.I. system may enhance patient's safety with the use of a minimally invasive extracorporeal circulation system. We consider both systems equally safe for clinical use.

Flow Awareness as a New Safety Device for Cardiopulmonary Bypass

Safety devices such as bubble detectors and level detectors have been in use for more than 40 years and initially reduced the risks associated with gaseous emboli during cardiopulmonary bypass; however, the risks have not been eliminated. This research explored a new safety device designed to further reduce these risks: Flow Awareness Technology. This device visually alerts the perfusionist when the ratio of venous return does not equal the amount of arterial flow. To determine the efficacy of this device, 33 participants with no perfusion background were randomly assigned to Group A (flow awareness only), Group B (level detector only), or Group C (control). These participants were instructed to turn off the arterial pump when they noticed that the fluid in the venous reservoir had begun to drop or if their assigned safety device was triggered. The venous line was fully occluded at times unknown to the participants. These times coincided with before, during, or after times that the participants were expected to paper-chart known values. Each participant's amount of fluid lost (in milliliters) from the reservoir and reaction time (in seconds) to shut off the arterial roller pump were measured. Group A lost an average of 80.8 mL, Group B lost an average of 173.6 mL, and Group C lost an average of 140.3 mL. Average measured time for each group is as follows: Group A took 2.16 seconds, Group B took 4.31 seconds, and Group C took 4.09 seconds to shut off the arterial pump. Statistics support the hypothesis that Flow Awareness Technology significantly reduces the reaction time to an adverse event such as a sudden occlusion of the venous line, thus reducing the amount of fluid lost during such an event.

A 24-hour perioperative case study on argatroban use for left ventricle assist device insertion during cardiopulmonary bypass and veno-arterial extracorporeal membrane oxygenation

A 44-year-old male with ongoing chest pain and left ventricular ejection fraction <20% was transferred from a peripheral hospital with intra-aortic balloon pump placement following a non-ST-elevation myocardial infarction (STEMI). The patient underwent emergent multi-vessel coronary artery bypass grafting requiring veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) on post-operative day (POD)#9 secondary to cardiogenic shock with biventricular failure. Due to clot formation, an oxygenator change-out was necessary shortly after initiation. Following a positive heparin-induced thrombocytopenia (HIT) assay, a total circuit exchange was required to eliminate all heparin coating and argatroban was deemed the anticoagulant of choice due to acute kidney injury. On POD#24, the decision was made to implant a left ventricle assist device (LVAD) as a bridge to heart transplantation. There was difficulty achieving an activated clotting time (ACT) >400 s: multiple argatroban bolus doses were required, along with accelerated up-titration of infusion dosing. Despite maintaining an ACT >484 s, clot formation was observed in the cardiotomy reservoir prior to separation. Subsequently, the patient developed severe disseminated intravascular coagulopathy, with both intra-cardiac and intravascular thrombi, requiring massive transfusion and continuous cell saving due to severe hemorrhage post cardiopulmonary bypass (CPB). The patient received a total of 105 units of plasma, 74 units of packed red cells, 19 units of platelets, 13 bottles of 5% albumin, 6 units of cryoprecipitate and 2 doses of factor VIIa intraoperatively over the course of 24 hours. A total of 19.7 L of washed red blood cells were returned to the patient from the cell saver. With the LVAD in place, the patient developed transfusion-related acute lung injury and acute respiratory distress syndrome with right ventricular dysfunction requiring VA ECMO once again. On POD#30, ECMO was discontinued and the patient was discharged from the intensive care unit (ICU) on POD 66. After a very complex post-operative stay with numerous surgeries and extensive rehabilitation, the patient was discharged home with the LVAD on POD#112.

Potential Deleterious Interactions between Certain Chemical Compounds and a Thermoplastic Polyurethane Heat Exchanger Membrane Oxygenator

Extracorporeal membrane oxygenation (ECMO) has become a powerful tool in the race to reverse failure to rescue events. Rapid implementation set the stage for the advent of the 30-day wet-priming storage as a standard practice. A recent alert regarding methylene blue (MB) unidirectional leach from patient's circulation through the oxygenator thermoplastic polyurethane (TPU) heat-exchanger membrane into the heater-cooler unit (HCU) water bath led us to believe that despite reassurances, the reverse process might be possible. To that effect, we performed a pilot in vitro experiment. We tested three adult ECMO sets (Adult Quadrox iD Oxygenator, Getinge, Doral, FL) probing for the transfer of MB between the water bath of a Sarns Dual Heater Cooler (Terumo Corporation, Ann Arbor, MI) and the circuit stored wet-primed for 30 days. In each test, 1,500 mg of reconstituted MB (HiMedia, Mumbai, India) were added to the 7.5 L of water in the HCU, circulated for 6 hours on which the water lines were disconnected and the setup was stored for 30 days. The primed circuit was tested for MB transfer at days 0, 13, and 30 by means of optical density (OD) at 665 nm and 26.5°C. Transference of MB from the HCU water bath into the ECMO circuit could be detected as early as day 13 after setup, achieving significant values by day 30 (median OD .019 (.014-.021). Expected OD if no diffusion present: 0. The complete separation of water interfaces between the patient's circuit and the HCU water bath may prove to be more dogma than fact when certain chemical substances are used in conjunction with TPU membrane oxygenators. Whether the transfer of substances is due to chemical processes or molecular weight needs further evaluation. Meanwhile, the use of chemicals for the cleaning of the HCU should be mindful of potential noxious effects.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Blood Electrolytes and Metabolites-A Randomized Controlled Trial

Cardiac surgery with cardiopulmonary bypass (CPB) causes an acute lung ischemia-reperfusion injury, which can develop to pulmonary dysfunction postoperatively. This sub-study of the Pulmonary Protection Trial aimed to elucidate changes in arterial blood gas analyses, inflammatory protein interleukin-6, and metabolites of 90 chronic obstructive pulmonary disease patients following two lung protective regimens of pulmonary artery perfusion with either hypothermic histidine-tryptophan-ketoglutarate (HTK) solution or normothermic oxygenated blood during CPB, compared to the standard CPB with no pulmonary perfusion. Blood was collected at six time points before, during, and up to 20 h post-CPB. Blood gas analysis, enzyme-linked immunosorbent assay, and nuclear magnetic resonance spectroscopy were used, and multivariate and univariate statistical analyses were performed. All patients had decreased gas exchange, augmented inflammation, and metabolite alteration during and after CPB. While no difference was observed between patients receiving oxygenated blood and standard CPB, patients receiving HTK solution had an excess of metabolites involved in energy production and detoxification of reactive oxygen species. Also, patients receiving HTK suffered a transient isotonic hyponatremia that resolved within 20 h post-CPB. Additional studies are needed to further elucidate how to diminish lung ischemia-reperfusion injury during CPB, and thereby, reduce the risk of developing severe postoperative pulmonary dysfunction.

Lung Protection Strategies during Cardiopulmonary Bypass Affect the Composition of Bronchoalveolar Fluid and Lung Tissue in Cardiac Surgery Patients

Pulmonary dysfunction is among the most frequent complications to cardiac surgeries. Exposure of blood to the cardiopulmonary bypass (CPB) circuit with subsequent lung ischemia-reperfusion leads to the production of inflammatory mediators and increases in microvascular permeability. The study aimed to elucidate histological, cellular, and metabolite changes following two lung protective regimens during CPB with Histidine-Tryptophan-Ketoglutarate (HTK) enriched or warm oxygenated blood pulmonary perfusion compared to standard regimen with no pulmonary perfusion. A total of 90 patients undergoing CPB were randomized to receiving HTK, oxygenated blood or standard regimen. Of these, bronchoalveolar lavage fluid (BALF) and lung tissue biopsies were obtained before and after CPB from 47 and 25 patients, respectively. Histopathological scores, BALF cell counts and metabolite screening were assessed. Multivariate and univariate analyses were performed. Profound histological, cellular, and metabolic changes were identified in all patients after CPB. Histological and cellular changes were similar in the three groups; however, some metabolite profiles were different in the HTK patients. While all patients presented an increase in inflammatory cells, metabolic acidosis, protease activity and oxidative stress, HTK patients seemed to be protected against severe acidosis, excessive fatty acid oxidation, and inflammation during ischemia-reperfusion. Additional studies are needed to confirm these findings.