Feilong Hei

Venoarterial Extracorporeal Membrane Oxygenation in Adult Patients: Predictors of Mortality.

Background: Extracorporeal membrane oxygenation is a cardiopulmonary supportive therapy. In this study, we reviewed our experience with extracorporeal membrane oxygenation support and tried to identify measurable values which might predict in-hospital mortality. Methods: From January 2004 through December 2008, 50 of 21,298 adult patients received venoarterial extracorporeal membrane oxygenation. We retrospectively analyzed clinical records of these 50 consecutive patients. Details of demographics, preoperative measurements, clinical characteristics at the time of extracorporeal membrane oxygenation implantation, extracorporeal membrane oxygenation-related complications and in-hospital mortality were collected. Logistic regression analyses were performed to investigate predictors of mortality. A p-value ≤ 0.05 was accepted as significant. Results: Thirty-eight patients were weaned from extracorporeal membrane oxygenation and 33 patients survived to discharge. The overall survival rate was 66%. In a multiple logistic regression analysis, blood lactate level before initiation of extracorporeal membrane oxygenation was a risk factor associated with in-hospital mortality (OR 1.27 95% CI 1.042-1.542). To evaluate the utility of the lactate in predicting mortality, a conventional receiver operating characteristic curve was produced. Sensitivity and specificity were optimal at a cut-off point of 12.6mmol/L, with an area under the curve of 0.752. The positive and negative predictive values were 73.3% and 83.9%, respectively. Conclusions: Extracorporeal membrane oxygenation is a justifiable alternative treatment for postoperative refractory cardiac and pulmonary dysfunction which could rescue more than sixty percent of otherwise fatal patients. Patients with pre-extracorporeal membrane oxygenation lactate levels above 12.6mmol/L are at higher risks for in-hospital death. Evidence-based therapy for this group of high risk patients is needed.BACKGROUND Extracorporeal membrane oxygenation is a cardiopulmonary supportive therapy. In this study, we reviewed our experience with extracorporeal membrane oxygenation support and tried to identify measurable values which might predict in-hospital mortality. METHODS From January 2004 through December 2008, 50 of 21,298 adult patients received venoarterial extracorporeal membrane oxygenation. We retrospectively analyzed clinical records of these 50 consecutive patients. Details of demographics, preoperative measurements, clinical characteristics at the time of extracorporeal membrane oxygenation implantation, extracorporeal membrane oxygenation-related complications and in-hospital mortality were collected. Logistic regression analyses were performed to investigate predictors of mortality. A p-value < or = 0.05 was accepted as significant. RESULTS Thirty-eight patients were weaned from extracorporeal membrane oxygenation and 33 patients survived to discharge. The overall survival rate was 66%. In a multiple logistic regression analysis, blood lactate level before initiation of extracorporeal membrane oxygenation was a risk factor associated with in-hospital mortality (OR 1.27 95% CI 1.042-1.542). To evaluate the utility of the lactate in predicting mortality, a conventional receiver operating characteristic curve was produced. Sensitivity and specificity were optimal at a cut-off point of 12.6 mmol/L, with an area under the curve of 0.752. The positive and negative predictive values were 73.3% and 83.9%, respectively. CONCLUSIONS Extracorporeal membrane oxygenation is a justifiable alternative treatment for postoperative refractory cardiac and pulmonary dysfunction which could rescue more than sixty percent of otherwise fatal patients. Patients with pre-extracorporeal membrane oxygenation lactate levels above 12.6 mmol/L are at higher risks for in-hospital death. Evidence-based therapy for this group of high risk patients is needed.

Predictors of Acute Renal Failure During Extracorporeal Membrane Oxygenation in Pediatric Patients After Cardiac Surgery

Acute renal failure (ARF) is associated with increased mortality in pediatric extracorporeal membrane oxygenation (ECMO). The aim of this study was to identify predictors of ARF during ECMO in pediatric patients after cardiac surgery. A retrospective study analyzed 42 children (≤15 years) after cardiac surgery requiring venous-arterial ECMO between December 2008 and December 2014 at Fuwai Hospital. ARF was defined as ≥300% rise in serum creatinine (SCr) concentration from baseline or application of dialysis. Multivariate logistic regression was performed to identify the predictors of ARF during ECMO. A total of 42 children (age, interquartile range [IQR], 13.0 [7.2-29.8] months; weight, IQR, 8.5 [6.7-11.0] kg) after cardiac surgery requiring ECMO were included in this study. The total survival rate was 52.4%, and the incidence of ARF was 40.5%. As the result of univariate analysis, ECMO duration, cardiopulmonary resuscitation, maximum free hemoglobin (FHB) during ECMO, lactate level, and mean blood pressure before initiation of ECMO were entered in multiple logistic regression analysis. In multiple logistic regression analysis, FHB during ECMO (OR 1.136, 95% CI 1.023-1.261) and lactate level before initiation of ECMO (OR 1.602, 95% CI 1.025-2.502) were risk factors for ARF during ECMO after pediatric cardiac surgery. There was a linear correlation between maximum SCr and maximum FHB (Pearsons r = 0.535, P = 0.001). Maximum SCr during ECMO has also a linear correlation with lactate level before initiation of ECMO (Pearsons r = 0.342, P = 0.044). Increased FHB during ECMO and high lactate level before initiation of ECMO were risk factors for ARF during ECMO in pediatric patients after cardiac surgery.

The Protective Effect of St. Thomas Cardioplegia Enriched With Zacopride on the Isolated Rat Heart

The activation of the heart inward rectifier potassium channel (I(K1) ) can reduce the injury of myocardial cells by shortening the action potential duration and reducing intracellular calcium overload. Zacopride is a selective I(K1) agonist and suppresses triggered arrhythmias in rat hearts. This investigation studied the effects of St. Thomas (ST) cardioplegia enriched with Zacopride on the isolated rat heart model. Sprague-Dawley rat hearts were harvested and perfused for 20 minutes with 37°C Krebs-Henseleit (KH) buffer followed by 15 minute perfusion with 4°C calcium-free KH buffer in the Control group (Con, n = 8), ST cardioplegia in the ST group (ST, n = 8) and ST cardioplegia with Zacopride in the STZ group (STZ, n = 8). After 45 minutes of arresting, all hearts were reperfused with 37°C KH buffer for 60 minutes. Hearts in the STZ group arrested faster than the Con and ST groups (9.25 ± 2.38 s vs. 72.25 ± 8.1 s, 12.75 ± 2.87 s). The recovery of the left ventricular developed pressure, ± dP/dtmax, heart rate, and coronary flow in the STZ group is significantly better than the other two groups during reperfusion. Compared with the Con and ST groups, the STZ group showed significant decreases in the maximum carciac troponin I level (P < 0.05) and the infarct size (P < 0.05). The superoxide dismutase level in the STZ group increased during the first 20 minutes of reperfusion (P < 0.05). ST cardioplegia enriched with Zacopride has beneficial effects against ischemia-reperfusion injury in this isolated rat heart model.

Acidic buffer or plus cyclosporine A post-conditioning protects isolated rat hearts against ischemia-reperfusion injury.

BACKGROUND It is well documented that transient acidosis during reperfusion is protective. The aim of this study was to evaluate the cardioprotection of acidic buffer or plus cyclosporine A in isolated rat hearts after cardioplegic arrest. METHODS Langendorff-perfused Sprague-Dawley rat hearts were perfused for 20 min with Krebs-Henseleit (K-H) buffer followed by 30 min of crystalloid cardioplegia and 60 min of reperfusion. Control hearts were perfused with Krebs-Henseleit buffer. Acidic buffer post-conditioning hearts were perfused with acidic K-H buffer (pH 6.8) for the first 3 min of reperfusion. Acidic buffer plus cyclosporine A hearts were perfused with K-H acidic buffer (pH 6.8) containing cyclosporine A (0.2 μmol/L) for the first 3 min of reperfusion. RESULTS Compared with the control group, acidic buffer or plus cyclosporine A post-conditioning significantly improved myocardial performance, decreased cytochrome C release into the cytosol, increased Bcl-2 expression and decreased Bax expression, decreased sensitivity of mPTP-opening to [Ca2+] and the rate of apoptosis after reperfusion. CONCLUSION These findings suggested that acidic buffer or plus cyclosporine A post-conditioning prevented apoptosis-related mitochondrial permeabilization and provided the myocardial protection after cardioplegic arrest.Background: It is well documented that transient acidosis during reperfusion is protective. The aim of this study was to evaluate the cardioprotection of acidic buffer or plus cyclosporine A in isolated rat hearts after cardioplegic arrest. Methods: Langendorff-perfused Sprague–Dawley rat hearts were perfused for 20 min with Krebs–Henseleit (K-H) buffer followed by 30 min of crystalloid cardioplegia and 60 min of reperfusion. Control hearts were perfused with Krebs–Henseleit buffer. Acidic buffer post-conditioning hearts were perfused with acidic K-H buffer (pH 6.8) for the first 3 min of reperfusion. Acidic buffer plus cyclosporine A hearts were perfused with K-H acidic buffer (pH 6.8) containing cyclosporine A (0.2 μmol/L) for the first 3 min of reperfusion. Results: Compared with the control group, acidic buffer or plus cyclosporine A post-conditioning significantly improved myocardial performance, decreased cytochrome C release into the cytosol, increased Bcl-2 expression and decreased Bax expression, decreased sensitivity of mPTP-opening to [Ca2+] and the rate of apoptosis after reperfusion. Conclusion: These findings suggested that acidic buffer or plus cyclosporine A post-conditioning prevented apoptosisrelated mitochondrial permeabilization and provided the myocardial protection after cardioplegic arrest.

Differentiation of Urine-Derived Human Induced Pluripotent Stem Cells to Alveolar Type II Epithelial Cells

Human alveolar type II (AT II) epithelial cells are valuable for the cellular therapy of lung disease. Human induced pluripotent stem cells (iPSCs) have the ability to generate AT II cells that can be used in modeling and treatment of lung disease caused by dysfunction of AT II cells. In this study, we present a simple, effective, and noninvasive way of obtaining human iPSCs from exfoliated renal epithelial cells, which exist in urine. Alkaline phosphatase (AP) staining, immunofluorescence staining, karyotyping, and teratoma experiments have proved that these iPSCs are pluripotent. Urinary iPSCs (UiPSCs) can differentiate into AT II cells with our four-step induction protocol. These cells have phenotypic properties similar to mature human AT II cells, such as outstretched and epithelium-like morphology and the specific expression markers of AT II cells (surfactant proteins A, B, and C). This study indicates that AT II cells can be generated from UiPSCs and these cells may be useful for the study of human lung development and regenerative medicine.

Plasma Free Hemoglobin Is a Predictor of Acute Renal Failure During Adult Venous-Arterial Extracorporeal Membrane Oxygenation Support

OBJECTIVE Hemolysis is a common and severe complication during extracorporeal membrane oxygenation (ECMO). Increased plasma free hemoglobin (PFHb) is related to renal injury. The aim of this study was to investigate whether increased PFHb during adult venous-arterial ECMO was associated with acute renal failure (ARF). DESIGN A retrospective, observational, single-center study. SETTING Fuwai Hospital in Beijing, China. PARTICIPANTS The study comprised 84 venous-arterial ECMO patients. INTERVENTIONS None. MEASUREMENTS AND MAIN RESULTS A total of 84 consecutive adult patients (≥18 years) with cardiac diseases requiring venous-arterial ECMO support were studied retrospectively. Demographics of patients, clinical and ECMO characteristics, and PFHb level were collected within the first 3 days after ECMO. ARF was defined as a≥300% rise in serum creatinine from baseline or application of dialysis. Repeated measurement analysis of variance revealed that the main effect for the non-ARF group and ARF group in PFHb (p = 0.002) was significant. A significant main effect for time points (p<0.001) and time×group interaction (p = 0.014) in PFHb was obtained. In a multiple logistic regression model, peak PFHb during ECMO (odds ratio 1.052, 95% confidence interval 1.016-1.089, p = 0.005) was a risk factor for ARF during ECMO and patients who underwent heart transplantation (odds ratio 0.240, 95% confidence interval 0.060-0.964, p = 0.044) experienced less ARF. There was a linear correlation between peak serum creatinine and peak PFHb (Spearmans r = 0.223, p = 0.042). CONCLUSIONS Increased PFHb is a predictor of ARF among adult patients on venous-arterial ECMO support.

Pharmacological postconditioning protects isolated rat hearts against ischemia-reperfusion injury: the role of mitochondrial permeability transition pore.

Postconditioning has been verified to provide cardioprotection and is associated with the state of mitochondrial permeability transition pore. However, there are a few limitations with clinical use of classic postconditioning; therefore, the purpose of this investigation was to study whether inhibition of mitochondrial permeability transition pore opening with cyclosporine A also provided cardioprotection. Langendorff-perfused Sprague–Dawley rat hearts were perfused for 20 minutes with Krebs–Henseleit buffer followed by 30 minutes of crystalloid cardioplegia and 60 minutes of reperfusion. Control hearts (Con group) were reperfused with Krebs– Henseleit buffer. Postconditioning hearts (Ipo group) were with six cycles of 10 seconds reocclusion separated by 10 seconds perfusion before reperfusion. Cyclosporine A postconditioning hearts (CsA group) were reperfused with Krebs–Henseleit buffer containing 0.8 &mgr;mol/L cyclosporine A at first 5 minutes of reperfusion. Compared with Con group, myocardial performance was better preserved in CsA group. Mitochondrial outer membrane integrity was preserved, with less cytosolic diffusion of cytochrome C (p < 0.05) and less frequency of terminal deoxynucleotidyl transferase–mediated deoxyuridine triphosphate (dUTP) nick end labeling–positive myocytes in Ipo and CsA group (p < 0.05). Postconditioning prevented apoptosis-related mitochondrial permeabilization and dysfunction after cardioplegic arrest. Cyclosporine A postconditioning had a better effect than classic postconditioning in myocardial performance.

Retrospective analysis of 99 patients with the application of extracorporeal membrane oxygenation in Fuwai Hospital.

The purpose of this study was to retrospectively summarize and analyze the data of 99 cases with the application of consecutive extracorporeal membrane oxygenation (ECMO) from December 2004 to August 2008 in Fuwai Hospital. The intersurface of the ECMO equipment system was completely heparin coated. All patients received venoarterial ECMO, and the activated clotting time was maintained between 120 and 180 seconds. The heparin dose was 5–20 U · kg−1 · h−1. Mean blood flow was 40–220 ml · kg−1 · min−1 during ECMO assisted period. The shortest ECMO time was 12 hours, and the longest was 504 hours (mean time, 119.45 ± 80.20 hours). Sixty patients (60.6%) weaned from ECMO successfully; 54 of them (84%) were discharged, and six died of postoperative complications. Thirty-nine patients could not wean from ECMO. Total discharge rate was 54.5%. ECMO is an effective mechanical assistant therapy for cardiac and pulmonary failure after cardiac surgery. Earlier use of ECMO for heart lung failure patients and avoidance of irreversible damage to the main organs are still the key points in the success of ECMO.

Effect of different albumin concentrations in extracorporeal circuit prime on perioperative fluid status in young children.

This study examined the effects of different dosages of albumin priming for extracorporeal circuit (ECC) on perioperative fluid status and fluid management in young children. A total of 151 consecutive pediatric patients (2–36 months old) scheduled for open heart surgery, were divided into two groups randomly, to receive either a 3% albumin solution (L group, n = 68) or a 5% albumin (H group, n = 83). Perioperative fluid intake, urine output, blood loss, diuretic dosage, the use of allogeneic blood products, ultrafiltration, and daily balance were recorded for 24 hrs in intensive care unit (ICU). Serial hematocrits, colloid osmotic pressure (COP) were measured. Outcomes and complications were documented. There were no significant differences in demographics, types of surgical procedures, baseline data such as hemoglobin, COP, and serum albumin. Patients in H group had significantly higher COPs, less urine output and more diuretic usage during operation and postoperatively (p < 0.05); at 6 hrs postoperatively, there were no differences between two groups. No statistically significant differences were found between the two groups in blood loss and the amount of allogenic blood products infused, length of mechanical ventilation, ICU or hospital stay, complications, or mortality. Higher concentration of albumin prime in ECC showed decreased positive fluid balances, but produced less urine output and required more diuretic usage postoperatively. Thus, no significant clinical benefit resulted from the increased dosage.

Cardiopulmonary bypass techniques and clinical outcomes in Beijing Fuwai Hospital: a brief clinical review.

The purpose of this study is to briefly summarize cardiopulmonary bypass (CPB) techniques and clinical outcomes in Beijing Fuwai Hospital. This article introduces routine CPB techniques in Fuwai Hospital, including CPB instruments, circuit setup, priming, conventional CPB management, myocardial protection, deep hypothermic circulatory arrest, ultrafiltration, autologous cell saver blood transfusion, and extracorporeal membrane oxygenation (ECMO). Clinical outcomes and further improvements of CPB management are also discussed. In 2008, 7,607 cases of cardiac surgery were performed in Fuwai Hospital, including congenital heart disease (48.33%), coronary artery disease (23.30%), rheumatic heart disease (19.45%), blood vessel disease (5.90%), reoperative surgery (1.70%), and other diseases (1.33%). The use of off-pump coronary artery bypass grafting (CABG) in isolated CABG was >50%. Thirty-eight cases of heart transplantation were also included. Total operative mortality in 2008 was 1.2%. Average postoperative stay was 9.5 days. CPB time was <120 minutes in >70% of the patients, and aortic cross-clamping time was <60 minutes in >50% of the cases. The self-recovery rate in the blood cardioplegia group (69.50%) was lower than the crystalloid cardioplegia group (97.40%). Thirty-five patients underwent cardiac surgery, and one patient from the cardiac internal medicine wards required ECMO support. Twenty-seven patients (75%, mean support time: 123.6 ± 54.1 hours) were weaned off ECMO successfully and discharged without severe complications. In conclusion, clinical CPB protocol used in Beijing Fuwai Hospital is a safe, simple, and conventional CPB management system that is suitable for practical clinical application in China. Further optimization is still needed to improve perfusion quality.