Key Points for Curbing Cardiopulmonary Bypass Inflammation

Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention

Cardiopulmonary bypass (CPB) is a common technique in cardiac surgery but is associated with acute kidney injury (AKI), which carries considerable morbidity and mortality. In this review, we explore the range and definition of CPB-associated AKI and discuss the possible impact of different disease recognition methods on research outcomes. Furthermore, we introduce the specialized equipment and procedural intricacies associated with CPB surgeries. Based on recent research, we discuss the potential pathogenesis of AKI that may result from CPB, including compromised perfusion and oxygenation, inflammatory activation, oxidative stress, coagulopathy, hemolysis, and endothelial damage. Finally, we explore current interventions aimed at preventing and attenuating renal impairment related to CPB, and presenting these measures from three perspectives: (1) avoiding CPB to eliminate the fundamental impact on renal function; (2) optimizing CPB by adjusting equipment parameters, optimizing surgical procedures, or using improved materials to mitigate kidney damage; (3) employing pharmacological or interventional measures targeting pathogenic factors.

A modified low-priming cardiopulmonary bypass system in patients undergoing cardiac surgery with medium risk of transfusion: A randomized controlled trial

Objectives

The FUWAI-SAVE system is a modified low-priming cardiopulmonary bypass (CPB) system. The study aimed to explore whether the FUWAI-SAVE system can reduce the perioperative blood transfusion and its impact on other postoperative complications during cardiac surgery.

Metohds

This study was a single-center, single-blind, randomized controlled trial, registered at the Chinese Clinical Trial Registry (identifier: ChiCTR2100050488). Adult patients undergoing cardiac surgery with CPB and intermediate risk for transfusion risk stratification were randomly assigned to an intervention group (FUWAI-SAVE group) or a control group (conventional group). The primary endpoint of the study was the peri-CPB red blood cell transfusion (RBC) rate. The secondary endpoints included the transfusion rate of other blood products, the amount of blood products transfused, the incidence of major complications, in-hospital mortality, and others.

Results

360 patients were randomized from December 9, 2021, to January 30, 2023. The rate of the primary endpoint was significantly lower in the FUWAI-SAVE group compared to the control group [ OR (95%CI): 0.649 (0.424-0.994)]. Meanwhile, the amount of RBC transfusion during the peri-CPB period was significantly lower in the FUWAI-SAVE group compared to the control group, with a mean difference of -0.626 (-1.176 to -0.076) units. The occurrence rate of major complications did not differ significantly between the two groups.

Conclusions

Among adult patients undergoing cardiac surgery with CPB, the application of the FUWAI-SAVE system significantly reduced RBC transfusion rate and amount. The FUWAI-SAVE system can be considered an important component of comprehensive blood management strategies in cardiac surgery.

Biochemical Changes in Cardiopulmonary Bypass in Cardiac Surgery: New Insights

Patients undergoing coronary revascularization with extracorporeal circulation or cardiopulmonary bypass (CPB) may develop several biochemical changes in the microcirculation that lead to a systemic inflammatory response. Surgical incision, post-CPB reperfusion injury and blood contact with non-endothelial membranes can activate inflammatory signaling pathways that lead to the production and activation of inflammatory cells, with cytokine production and oxidative stress. This inflammatory storm can cause damage to vital organs, especially the heart, and thus lead to complications in the postoperative period. In addition to the organic pathophysiology during and after the period of exposure to extracorporeal circulation, this review addresses new perspectives for intraoperative treatment and management that may lead to a reduction in this inflammatory storm and thereby improve the prognosis and possibly reduce the mortality of these patients.

Turbulence in surgical suction heads as detected by MRI

BACKGROUND

Blood loss is common during surgical procedures, especially in open cardiac surgery. Allogenic blood transfusion is associated with increased morbidity and mortality. Blood conservation programs in cardiac surgery recommend re-transfusion of shed blood directly or after processing, as this decreases transfusion rates of allogenic blood. But aspiration of blood from the wound area is often associated with increased hemolysis, due to flow induced forces, mainly through development of turbulence.

METHODS

We evaluated magnetic resonance imaging (MRI) as a qualitative tool for detection of turbulence. MRI is sensitive to flow; this study uses velocity-compensated T1-weighted 3D MRI for turbulence detection in four geometrically different cardiotomy suction heads under comparable flow conditions (0-1250 mL/min).

RESULTS

Our standard control suction head Model A showed pronounced signs of turbulence at all flow rates measured, while turbulence was only detectable in our modified Models 1-3 at higher flow rates (Models 1 and 3) or not at all (Model 2).

CONCLUSIONS

The comparison of flow performance of surgical suction heads with different geometries via acceleration-sensitized 3D MRI revealed significant differences in turbulence development between our standard control Model A and the modified alternatives (Models 1-3). As flow conditions during measurement have been comparable, the specific geometry of the respective suction heads must have been the main factor responsible. The underlying mechanisms and causative factors can only be speculated about, but as other investigations have shown, hemolytic activity is positively associated with degree of turbulence. The turbulence data measured in this study correlate with data from other investigations about hemolysis induced by surgical suction heads. The experimental MRI technique used showed added value for further elucidating the underlying physical phenomena causing blood damage due to non-physiological flow.

Common Inflammatory Markers and Outcome After Pediatric Cardiac Surgery With High Thoracic Epidural Anesthesia: A Randomized Controlled Study

Background: High thoracic epidural analgesia (HTEA) plays a pivotal role in reducing stress and neuroendocrine response in cardiac surgeries. Aim: The primary objective is to assess the effect of HTEA, in pediatric cardiac surgery, on inflammatory markers (interleukin [IL]-6, IL-8, and tumor necrosis factor-α). The secondary objectives are to assess its effect on various organ systems, that is, pulmonary (PaO2, P/F ratio), renal (Creatinine clearance, somatic near infrared spectroscopy [NIRS], serum neutrophil gelatinase-associated lipocalin values), cardiac (cardiac index, serum Trop-I, and lactate levels), mechanical ventilation duration, and length of stay in hospital (LOS). Methods: The study included 188 pediatric patients, who underwent, on-pump cardiac surgery randomized into the Epidural Group (n = 92) and Non-Epidural Group (n = 96). After general anesthesia, a 23 G epidural catheter was placed at the T4-5 level with a Bupivacaine infusion while the Non-epidural Group received fentanyl infusion. Blood samples were collected at four-time points, T0(preop), T1(4 h), and on the first and second postoperative days (T2 and T3). Results: The inflammatory markers were reduced, while the outcomes variables of mechanical ventilation (MV) duration had lower values in the epidural group (19.5 h vs 47.3 h, P = .002). LOS was shorter (10.1 days vs 13.3 days, P = .016). pO2, PF ratio, and renal NIRS values were better in the Epidural Gp, while other parameters were comparable. Non-epidural Gp had more complications esp. Acute kidney injury requires RRT. Conclusion: HTEA use in pediatric, on-pump cardiac surgery offers a favorable profile in terms of reduction in the inflammatory markers and positive effect on the organ systems with lesser MV duration and the LOS.

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.

The effect of preoperative chest physiotherapy on oxygenation and lung function in cardiac surgery patients: a randomized controlled study

BACKGROUND

Postoperative pulmonary complications in patients who undergo open heart surgery are serious life-threatening conditions. Few studies have investigated the potentially beneficial effects of preoperative physiotherapy in patients undergoing cardiac surgery.

OBJECTIVES

Assess the effects of preoperative chest physiotherapy on oxygenation and lung function in patients undergoing open heart surgery.

DESIGN

Randomized, controlled.

SETTING

University hospital.

PATIENTS AND METHODS

Patients with planned open heart surgery were randomly allocated into an intervention group of patients who underwent a preoperative home chest physiotherapy program for one week in addition to the traditional postoperative program and a control group who underwent only the traditional postoperative program. Lung function was assessed daily from the day before surgery until the seventh postoperative day.

MAIN OUTCOME MEASURES

Differences in measures of respiratory function and oxygen saturation. Length of postoperative hospital stay was a secondary outcome.

SAMPLE SIZE

100 patients (46 in intervention group, 54 in control group).

RESULTS

Postoperative improvements in lung function and oxygen saturation in the intervention group were statistically significant compared with the control group. The intervention group also had a statistically significant shorter hospital stay (P<.01).

CONCLUSION

Preoperative chest physiotherapy is effective in improving respiratory function following open heart surgery.

LIMITATIONS

Relatively small number of patients.

CONFLICT OF INTEREST

None.

REGISTRATION

ClinicalTrials.gov (NCT04665024).

Preoperative Status of Gut Microbiota Predicts Postoperative Delirium in Patients With Gastric Cancer

INTRODUCTION

Post-operative delirium (POD) is a serious complication which occurs after surgery, especially in the elderly undergoing abdominal surgery. Increasing evidence has revealed an association between the gut microbiota and psychological disorders involving the "brain-gut" axis. However, the association between the pathogenesis of POD after abdominal surgery in aging and composition of the gut microbiota remains unclear.

METHODS

Forty patients (≥65 years old) who underwent abdominal surgery were included in the study. Twenty patients had POD, whereas 20 patients did not. POD was diagnosed and assessed using the confusion assessment method (CAM) during the postoperative period. Total DNA fractions were extracted from all fecal samples of patients. 16S rRNA sequencing was performed to determine the composition of the gut microbiota. The quality of the samples was determined by calculating the α- and β-diversities.

RESULTS

The α- and β-diversities indicated that the samples were eligible for detection and comparison. We observed multiple differentially abundant bacteria in patients with and without POD. Generally, Proteobacteria, Enterbacteriaceae, Escherichia shigella, Klebsiella, Ruminococcus, Roseburia, Blautia, Holdemanella, Anaerostipes, Burkholderiaceae, Peptococcus, Lactobacillus, and Dorea were abundant in the POD cohort, whereas Streptococcus equinus and Blautia hominis were abundant in the control cohort. The results of receiver operating characteristic (ROC) curve analysis showed that the area under the curve (AUC) of Escherichia shigella was 0.75. Phenotype prediction showed that the gut microbiota may influence POD by altering the tolerance to oxidative stress.

CONCLUSION

There were significant associations between the pathogenesis of POD and composition of the gut microbiota. Escherichia shigella are promising diagnostic bacterial species for predicting POD onset after abdominal surgery in elderly people.

CLINICAL TRIAL REGISTRATION

http://www.chictr.org.cn/index.aspx, Chinese Clinical Trial Registry ChiCTR200030131.

Risk factors for prolonged intensive care unit stays in patients after cardiac surgery with cardiopulmonary bypass: A retrospective observational study

Objectives

Patients after cardiac surgery with cardiopulmonary bypass (CPB) require a stay in the ICU postoperatively. This study aimed to investigate the incidence of prolonged length of stay (LOS) in the ICU after cardiac surgery with CPB and identify associated risk factors.

Methods

The current investigation was an observational, retrospective study that included 395 ICU patients who underwent cardiac surgery with CPB at a tertiary hospital in Guangzhou from June 2015 to June 2017. Data were obtained from the hospital database. Binary logistic regression modeling was used to analyze risk factors for prolonged ICU LOS.

Results

Of 395 patients, 137 (34.7%) had a prolonged ICU LOS (>72.0 h), and the median ICU LOS was 50.9 h. Several variables were found associated with prolonged ICU LOS: duration of CPB, prolonged mechanical ventilation and non-invasive assisted ventilation use, PaO₂/FiO₂ ratios within 6 h after surgery, type of surgery, red blood cell infusion during surgery, postoperative atrial arrhythmia, postoperative ventricular arrhythmia (all P < 0.05).

Conclusions

These findings are clinically relevant for identifying patients with an estimated prolonged ICU LOS, enabling clinicians to facilitate earlier intervention to reduce the risk and prevent resulting delayed recovery.

The Efficacy of Resin Hemoperfusion Cartridge on Inflammatory Responses during Adult Cardiopulmonary Bypass

AIM

This study aimed to evaluate the efficacy of the resin hemoperfusion device (HA380 hemoperfusion cartridge) on inflammatory responses during adult cardiopulmonary bypass (CPB).

METHODS

Sixty patients undergoing surgical valve replacement were randomized into the HP group (n = 30) with an HA380 hemoperfusion cartridge in the CPB circuit or the control group (n = 30) with the conventional CPB circuit. The results of routine blood tests, blood biochemical indexes, and inflammatory factors were analyzed at V0 (pre-CPB), V1 (CPB 30 min), V2 (ICU 0 h), V3 (ICU 6 h), and V4 (ICU 24 h).

RESULTS

The HP group had significantly lower levels of IL-6, IL-8, and IL-10. Significant estimation of group differences in the generalized estimating equation (GEE) models was also observed in IL-6 and IL-10. The HP group had significantly lower levels of creatinine (Cr), aminotransferase (AST), and total bilirubin (TBil) compared to the control group. The estimation of differences of Cr, AST, and TBil all reached statistical significance in GEE results. The HP group had significantly less vasopressor requirement and shorter mechanical ventilation time and ICU stay time as compared to the control group.

CONCLUSION

The HA380 hemoperfusion cartridge could effectively reduce the systemic inflammatory responses and improve postoperative recovery of patients during adult CPB.

Red blood cell exosome hemoglobin content increases after cardiopulmonary bypass and mediates acute kidney injury in an animal model

OBJECTIVE

Hemolysis, characterized by formation of free hemoglobin (Hb), occurs in patients undergoing cardiopulmonary bypass (CPB). However, there is no study of the dynamic changes in red blood cell (RBC)-derived exosomes (Exos) released during CPB, nor whether these particles mediate acute kidney injury (AKI).

METHODS

This study is a comprehensive time-course analysis, at baseline, 30 minutes, to 24 hours post-crossclamp release (XCR) to determine (1) Exos Hb content; (2) free Hb/heme, haptoglobin, hemopexin; and (3) urinary markers of AKI over the same time period. In addition, we developed a model system in Sprague-Dawley rats to test for AKI after intravenous injection of Exos Hb released during CPB.

RESULTS

In 30 patients undergoing CPB, there is a significant increase in plasma Hb-positive Exos but not microvesicles 30 minutes post-XCR versus other time points, with a simultaneous decrease in the haptoglobin/Hb ratio. These changes presage a significant increase in urine neutrophil gelatinase-associated lipocalin and kidney injury molecule-1 at 24 hours. Intravenous injection of plasma Exos (10^9-10 particles obtained 30 minutes post-XCR) into rats causes AKI at 72 hours, manifested by multifocal degeneration of proximal tubular epithelium. At 21 days, there is persistent tubular injury and interstitial fibrosis. Intravenous injection of Exos from 35-day-old stored RBCs into rats results in glomerular-tubular injury, increased kidney ferritin and hemoxygenase-1 expression, and significant elevation of kidney injury molecule-1 and proteinuria at 72 hours.

CONCLUSIONS

These combined studies raise the potential for RBC-derived Exos, released during CPB, to target the kidney and mediate AKI.

Association between postoperative changes in the gut microbiota and pseudopsia after cardiac surgery: prospective observational study

Background

Delirium after cardiac surgery affects mortality, but the mechanism remains unclear. Previous studies have reported gut microbiota are associated with brain activity. Systemic inflammation and antibiotics can damage the gut microbiota after cardiac surgery. We aimed to investigate changes in the gut microbiota and the association between the gut microbiota and delirium after cardiac surgery.

Methods

Twenty-one patients who underwent cardiac surgery were enrolled. Microbiota counts and fecal organic acid concentrations were measured in fecal samples harvested before surgery, just after surgery, and before discharge. To quantify the microbiota, we extracted total RNA fractions and examined gut microbiota composition using 16S and 23S rRNA-targeted quantitative-reverse Transcription-PCR. Postoperative delirium, insomnia, and pseudopsia were assessed for 1 week. Postoperative total bacterial counts changed significantly from 10.2 ± 0.2 log₁₀ cells/g of feces to 9.8 ± 0.5 in the first postoperative samples (p = 0.003) and 10.0 ± 0.4 in the samples before discharge (p = 0.039). Fecal pH was 6.9 ± 0.6 before surgery and 7.4 ± 0.7 in the first postoperative samples (p = 0.001). Postoperative Staphylococcus and Pseudomonas counts were significantly higher in patients with postoperative pseudopsia than in patients without pseudopsia (3.2 ± 1.3 vs. 5.4 ± 0.9; p = 0.012 and 1.7 ± 0.8 vs. 4.6 ± 2.7; p = 0.001).

Conclusions

Total bacterial counts were significantly lower after surgery and until discharge. Fecal pH was significantly higher than preoperative levels. Staphylococcus and Pseudomonas counts were significantly higher in patients with postoperative pseudopsia.

Pulmonary complications following cardiac surgery

Coronary heart disease is a common diseases of atherosclerosis. Despite the development of noninvasive therapies and the advancement of pharmacological methods and extensive drug regimens, coronary artery bypass grafting surgery is still the ultimate treatment option in many patients. Among the various complications following open heart surgery, one of the common difficulties is pulmonary complications associated with subsequent morbidity and mortality, which should be studied according to preoperative, perioperative, and postoperative factors. Preoperative factors include genetics, age, family history of pulmonary disease, smoking, coexisting disease, etc. Perioperative factors include surgical procedures like sternotomy incision, cardioplegia, and internal mammary artery harvesting; anaesthesia procedure effects like pulmonary collapse, maintenance drugs and morphine administration; and cardiopulmonary bypass pump by systemic inflammatory response syndromes. And finally, postoperative factors, especially mediastinitis and the role of nursing in the intensive care unit. Pulmonary complications after cardiac surgery include atelectasis, pleural effusions, pneumonia, pulmonary oedema, cardiogenic pulmonary oedema, acute respiratory distress syndrome, pulmonary embolism, phrenic nerve injury, pneumothorax, sternal wound infection, and mediastinitis, with different outbreaks in patients reported. Although the preoperative, perioperative, and postoperative factors play an important role in the occurrence of these complications, the preoperative factors, as factors that can be adjusted, should be considered more than the others and explained to the patient, and the preoperative patient’s assessment should be noted. Also, postoperative care with the goal of reducing infections and pulmonary complications should be addressed by the nursing team.

κ-opioid receptor agonists may alleviate intestinal damage in cardiopulmonary bypass rats by inhibiting the NF-κB/HIF-1α pathway

The aims of the present study were to investigate the protective effect of a κ-opioid receptor (KOR) agonist on intestinal barrier dysfunction in rats during cardiopulmonary bypass (CPB), as well as to examine the role of NF-κB and the transcription factor hypoxia-inducible factor-1α (HIF-1α) signaling pathway in the regulatory mechanism. A total of 50 rats were randomly divided into five groups, with 10 rats in each group: Sham surgery group (group Sham), CPB surgery group (group CPB), KOR agonist + CPB (group K), KOR agonist + specific KOR antagonist + CBP (group NK) and KOR agonist + NF-κB pathway specific inhibitor + CPB (group NF). Intestinal microcirculation was evaluated to determine intestinal barrier dysfunction in rats following CPB surgery. Hematoxylin and eosin (H&E) staining was used to observe intestinal tissue injury in the rats. ELISA was used to detect the inflammatory factors interleukin (IL)-1β, IL-6, IL10 and tumor necrosis factor-α, and the oxidative stress factors superoxidase dismutase, malondialdehyde and nitric oxide in serum. In addition, ELISA was used to investigate the serum levels of the intestinal damage markers D-lactic acid, diamine oxidase and intestinal fatty acid-binding protein. Western blotting was used to investigate the protein expression levels of tight junction proteins zonula occludens-1 and claudin-1. Furthermore, immunohistochemistry was used to examine intestinal injuries and western blotting was used to detect expression levels of NF-κB/HIF-1α signaling pathway-related proteins. H&E staining results suggested that the KOR agonist alleviated intestinal damage in the CPB model rats. This effect was reversed by the addition of a KOR antagonist. Further investigation of inflammatory and oxidative stress factors using ELISA revealed that the KOR agonist reduced the inflammatory and oxidative stress responses in the intestinal tissues of the CPB model rats. The ELISA results of intestinal damage markers and western blotting results of tight junction protein expression suggested that KOR agonist treatment may alleviate intestinal injury in CPB model rats. In addition, the western blotting and immunohistochemistry results suggested that KOR agonists may decrease the expression levels of NF-κB, p65 and HIF-1α in CPB. Collectively, the present results suggested that KOR agonists are able to ameliorate the intestinal barrier dysfunction in rats undergoing CPB by inhibiting the expression levels of NF-κB/HIF-1α signaling pathway-related proteins.

Evaluation of Inflammation Caused by Cardiopulmonary Bypass in a Small Animal Model

Extracorporeal circulation (ECC) methods are being increasingly used for mechanical support of respiratory and cardio-circulatory failure. Especially, cardiopulmonary bypass (CPB) during cardiovascular surgery, sustenance of the patient’s life by providing an appropriate blood flow and oxygen supply to principal organs. On the other hand, systemic inflammatory responses in patients undergoing cardiovascular surgery supported by CPB contribute significantly to CPB-associated mortality and morbidity. Our previous research showed that CPB causes a systemic inflammatory response and organ damage in a small animal CPB model. We have been studying the effects of hyperoxia and blood plasma substitute on CPB. In this review, we present a study focusing on the systemic inflammatory response during CPB, along with our findings.

Dexmedetomidine Exerts Brain-Protective Effects Under Cardiopulmonary Bypass Through Inhibiting the Janus Kinase 2/Signal Transducers and Activators of Transcription 3 Pathway

Brain injury is a major complication resulted from cardiopulmonary bypass (CPB). Dexmedetomidine (DEX) has potential brain-protective effects; however, the mechanism is unclear. The aim of this study is to investigate the effect of DEX on brain injury in CPB rats and its mechanism. The levels of interleukin-6 (IL-6), interleukin-10 (IL-10), S100β, and neuron-specific enolase (NSE) were measured by enzyme-linked immunosorbent assay. The hippocampus CA1 region in rats was observed by hematoxylin-eosin staining. Western blot and quantitative real-time polymerase chain reaction were performed to detect related proteins and mRNA expressions in the hippocampus tissues. We found that after CPB, the neuron cells in hippocampus CA1 region of rats were randomly arranged, and that the levels of IL-6, IL-10, S100β, NSE, Cleaved Caspase-3, and Bax were upregulated, while Bal-2 level was downregulated. However, after DEX treatment, the neuron cells arranged in an orderly manner, and the levels of IL-6, IL-10, S100β, NSE, Cleaved Caspase-3, and Bax were downregulated, but Bal-2 level was upregulated. DEX suppressed Janus kinase 2 (JAK2)/signal transducers and activators of transcription 3 (STAT3) pathway activated by CPB, ameliorated CPB-induced brain injury in rats by reducing inflammatory response, and inhibited neuronal apoptosis. The brain-protective effect of DEX may be related to the inhibition of the activation of JAK2/STAT3 pathway.

Current Evidence about Nutrition Support in Cardiac Surgery Patients-What Do We Know?

Nutrition support is increasingly recognized as a clinically relevant aspect of the intensive care treatment of cardiac surgery patients. However, evidence from adequate large-scale studies evaluating its clinical significance for patients&rsquo; mid- to long-term outcome remains sparse. Considering nutrition support as a key component in the perioperative treatment of these critically ill patients led us to review and discuss our understanding of the metabolic response to the inflammatory burst induced by cardiac surgery. In addition, we discuss how to identify patients who may benefit from nutrition therapy, when to start nutritional interventions, present evidence about the use of enteral and parenteral nutrition and the potential role of pharmaconutrition in cardiac surgery patients. Although the clinical setting of cardiac surgery provides advantages due to its scheduled insult and predictable inflammatory response, researchers and clinicians face lack of evidence and several limitations in the clinical routine, which are critically considered and discussed in this paper.

α7 nicotinic acetylcholine receptor agonist attenuates the cerebral injury in a rat model of cardiopulmonary bypass by activating the Akt/GSK3β pathway

α7 nicotinic acetylcholine receptor (α7nAchR) agonist treatment may provide a promising therapeutic effect for cerebral injuries. However, it is unclear whether the activation of α7nAchR agonist may reduce cerebral injuries induced by cardiopulmonary bypass (CPB). A total of 96 male Sprague‑Dawley rats were randomly divided into four groups (n=24/group): i) Sham operation group; ii) CPB group; iii) CPB + α7nAchR agonist group; and iv) CPB + α7nAchR agonist + α7nAchR antagonist group. Following treatment, 24 rats from each group were sacrificed and the serum and hippocampal tissues were collected. The serum expression levels of S100β, interleukin 6 and tumor necrosis factor α were evaluated by ELISA, hippocampal tissues were analyzed by histopathological examination using hematoxylin & eosin and terminal deoxynucleotidyl‑transferase‑mediated dUTP nick‑end labeling (TUNEL) staining and Caspase 3 expression in the hippocampal tissues was evaluated by immunohistochemistry. In addition, Caspase 3, Akt and glycogen synthase kinase 3β (GSK3β), as well as phosphorylated (p)‑Akt and (p)‑GSK3β were examined by western blot assay. The present study demonstrated that α7nAchR agonist treatment was able to alleviate pathological damage and inhibit hippocampal cell apoptosis and inflammatory response. α7nAchR agonist treatment also increased the expression levels of p‑Akt and p‑GSK3β, which indicated an upregulation in Akt/GSK3β signaling. These data suggested that α7nAchR agonist may provide a promising new therapeutic approach for cerebral injury caused by CPB.

Preoperative asymptomatic leukocytosis and postoperative outcome in cardiac surgery patients

BACKGROUND

Despite showing a prognostic value in general surgical patients, preoperative asymptomatic elevated white blood cell (WBC) count is not considered a risk factor for cardiac surgery. Whereas there is sporadic evidence of its value as a preoperative risk marker, it has not been looked at methodically as a specific index of outcome during cardiac surgery. Using a national database we sought to determine the relationship between preoperative WBC count and postoperative outcome in cardiac surgical patients.

METHODS

Cardiac surgeries were extracted from the 2007-2013 American College of Surgeons National Surgical Quality Improvement Program database. Leukocytosis was defined by a preoperative WBC count greater than 11,000 cells/μL. A univariate analysis compared the incidence of adverse outcomes for patients with and without leukocytosis. A multivariate logistic regression model was constructed in order to test whether leukocytosis was an independent predictor of morbidity and mortality.

RESULTS

Out of a total of 10,979 cardiac surgery patients 863 (7.8%) had preoperative leukocytosis. On univariate analysis, patients with leukocytosis experienced greater incidences of 30-day mortality, wound complications, and medical complications. Wound complications included surgical site infection as well as wound dehiscence. The medical complications included all other non-surgical causes of increased morbidity and infection leading to urinary tract infection, pneumonia, ventilator dependence, sepsis and septic shock. After stepwise model adjustment, leukocytosis was a strong predictor of medical complications (OR 1.22, 95% CI: 1.09-1.36, p = 0.002) with c-statistic of 0.667. However, after stepwise model adjustment leukocytosis was not a significant predictor of 30-day mortality and wound complications.

CONCLUSION

Preoperative leukocytosis is associated with adverse postoperative outcome after cardiac surgery and is an independent predictor of infection-related postoperative complications.

Differentiating between cold agglutinins and rouleaux: a case series of seven patients

We present a case series of seven patients with suspected cold agglutinin antibodies, discovered after initiation of bypass. Laboratory analysis of blood samples intraoperatively determined the cause of the aggregation to be rouleaux formation in three of the patients and cold agglutinins in the other four.