Acute kidney injury (AKI) is a common and serious clinical syndrome after cardiac surgery with the high morbidity and mortality.As the markers of AKI,Serum creatinine and urine output is not sensitive for early detection.Due to the lack of early biomakers for AKI,early effective treatment has been delayed.Identification of novel biomarkers for AKI has progressed to the clinical phase.Novel biomakers include neutrophil gelatinase-associated lipocalin,kidney injury molecule-1,Cystatin C,IL-18,and so on.In this article the author will review the current progress of these clinical and experimental novel AKI biomarkers.

Objective To analyze the risk factors leading to prolonged mechanical ventilation following valve replacement surgery with the purpose of improving the management of these patients.Methods The risk factors of prolonged mechanical ventilation at preoperative,operative and postoperative clinical data of 307 patients who underwent valve replacement surgery were retrospectively analyzed.Binary Logistic regression model was used to assess the factors.Results The time of mechanical ventilation after valve replacement surgery was (15 ± 35) h,and 31.6％ (97/307) of these patients underwent prolonged mechanical ventilation (＞ 8 h).Age ≥ 65 years (P =0.003),smoker (P =0.024),left ventricular ejection fraction (LVEF) preoperative (P =0.002),duration of operation (P =0.000),aortic block time (P =0.046),cardiopulmonary bypass time (P =0.030),number of replaced valve (P =0.001),volume of postoperative chest drainage (P =0.000) and postoperative complications (P =0.010) were risk factors of prolonged mechanical ventilation.Logistic regression analysis showed that LVEF (P =0.026),duration of operation(P =0.037),aortic block time (P =0.001),cardiopulmonary bypass time (P =0.013),number of replaced valve (P =0.017),volume of postoperative chest drainage (P =0.020) and postoperative complications (P =0.014) had extremely affection.Conclusions Greater importance should be attached to healthcare education,early treatment to avoid multivalvular involvement,preoperative heart function regulation,lower duration of operation especially aortic block time and cardiopulmonary bypass time,lower postoperative chest drainage and better preservation of organs during operation to decrease the rate of prolonged mechanical ventilation and optimize the clinical quality.

Objective To compare the different characteristics of adaptive support ventilation (ASV) and synchronized intermittent mandatory ventilation-pressure support ventilation (SIMV-PSV) mode in weaning patients after general anesthesia.Methods One hundred and twenty-eight patients received general anesthesia,ending in odd and even numbers by hospital number divided into ASV group (single number,62 cases) and SIMV-PSV group (double number,66 cases).The propofol dosage,duration of mechanical ventilation,duration of intubation,ventilator alarms,ventilator settings manipulations and each stage of the blood gas analysis,hemodynamic,respiratory mechanics were recorded.Results One hundred and twenty-eight patients completed the extubation.The propofol dosage,duration of mechanical ventilation,duration of intubation in ASV group were significantly shorter than those in SIMV-PSV group [(1.13 ± 0.33)mg/kg vs.(1.28 ±0.49) mg/kg,(169.8±36.5) min vs.(201.9 ±37.3) min,(197.2 ±38.9) min vs.(239.5 ± 42.3) min,P ＜ 0.05].There was no statistically significant difference in various stages of heart rate,mean arterial pressure,central venous pressure,pH,arterial carbon dioxide partial pressure,oxygenation index between two groups (P ＞0.05).In the first and second stages,tidal volume in ASV group was significantly higher than that in SIMV-PSV group [(543.6 ± 72.3) ml vs.(489.5 ± 68.7) ml,(513.9 ± 65.7)ml vs.(462.8 ± 61.7) ml,P＜ 0.05],respiratory rate in ASV group was significantly lower than that in SIMV-PSV group [(13.2 ± 3.6) times/min vs.(17.2 ±4.1) times/min,(15.1 ± 3.1) times/min vs.(16.8 ± 3.7)times/min,P ＜ 0.05].In the first stage,the mean airway pressure and peak airway pressure in ASV group were significantly lower than those in SIMV-PSV group [(8.2 ± 1.7) cm H2O (1 cm H2O =0.098 kPa) vs.(12.3 ± 3.1) cm H2O,(16.2 ± 2.9) cm H2O vs.(21.2 ± 4.3) cm H2O,P ＜ 0.05].The pulmonary dynamic compliance in ASV group was better than that in SIMV-PSV group [(64.8 ± 12.3) ml/cm H2O vs.(52.6 ±13.5) ml/cm H2O,P ＜ 0.05].The ventilator alarms,ventilator settings manipulations in ASV group were significantly shorter than those in SIMV-PSV group [(2.3 ± 1.6) times vs.(5.1 ± 1.9) times,(0.8 ± 0.5) times vs.(1.6 ± 0.8) times,P ＜ 0.05].Conclusion ASV weaning mode is safe and effective,which could accelerate the extubation and simplify the manipulation.

Objective To evaluate the hypothesis that neutrophil gelatinase-associated lipocalin(NGAL) ,kidney injury molecule-1(KIM-1)and Interleukin-18(IL-18) are early biomarker for acute kidney injury (AKI) in patients after coronary artery bypass graft surgery(CABG) .Methods 80 patients were recruited during September 2011 to May 2012 .The patients were divided into two groups according to the AKI criteria ,patients developed postoperative AKI in AKI group ;others did not postoperative developed AKI in non-AKI group .Before and 2 ,4 ,6 ,8 ,12 ,24 h after the CABG surgery ,the urine and serum sample were collected ,serum creatinine ,the urine and serum IL-18、NGAL、KIM-1 value were test by ELISA method .Results 13 of 80 cases(16 .25% )developed postoperative AKI according to the AKI criteria ,diagnosis with serum creatinine was only 12-48 h after cardiac surgery .Concen-trations of NGAL 、IL-18 in urine and serum at 2 h after CABG surgery ,concentrations of KIM-1 in urine and serum at 6 h were the powerful independent predictors of AKI by logistic regression analysis and ROC curve .Conclusion IL-18 in urine and serum at 2 h after CABG surgery were the powerful independent predictors of AKI ,and concentrations of KIM-1 in urine and serum at 6 h were the powerful independent predictors of AKI .Serous NGAL and IL-18 is better than urinary NGAL and IL-18 in diagnosis of AKI . Urinary KIM-1 was better than serous KIM-1 in diagnosis of AKI at 6 h .

Objective To investigate the correlation of possible risk factors with acute renal injury (AKI) after coronary artery bypass surgery (CABG) and explore if the incidence of AKI could be lower by off-pump CABG for kidney protection.Methods Two hundred and nine patients who underwent coronary artery bypass surgery in Nanjing First Hospital from September 2010 to November 2013 were recruited.The patients were divided into AKI group (fifty-five cases) and non-AKI group (one hundred and fifty-four cases) according to the AKI criteria and compared the possible risk factors between two the groups by univariate analysis and multivariate analysis.Results The index of female gender,body mass index,age,hypertension,basic serum creatinine,ejection fraction,the number of coronary atherosclerosis,cardiopulmonary bypass,IABP for circulatory support,postoperative low cardiac output,lactate in AKI group were higher than that in non-AKI group by univariate analysis (P ＜ 0.05).And basic serum creatinine,ejection fraction,cardiopulmonary bypass,postoperative low cardiac output showed a significantly statistical difference between two group by multivariate analysis.Conclusions Cardiopulmonary bypass,basic serum creatinine,ejection fraction,postoperative low cardiac output were independent risk factors.Off-pump CABG could benefit for kidney protection.

Objective To investigate the effects of dexmedetomidine on the inflammatory response during the aortic dissection perioperative period.Methods 53 patients with the type A aortic dissection who needed surgical treatment were randomly divided into the study group and the control group.Patients in the study group (group A) received dexmedetomidine (0.2-0.7 μg · kg-1 · h-1) while patients in the control group (group B) received morphine 0.2-0.6 mg/h to ease pain after they were admitted and continued to 48 h after the operation.The serum levels of TNF-α,MMPs,NE,NT-proBNP and CRP were measured in the patients at the time enrolled taking none of the two drugs(T0),before the operation(T1),immediately after the operation (T2) and 12 h (T3),24 h (T4),48 h (T5),72 h (T6) after the operation.MODS score and the length of stay in ICU were observed about the two groups of patients.Difference between the two groups was determined by the Student' s t-test.Single factor analysis of variance was used within the group.P ＜ 0.05 was considered statistically significant.Results Compared with the patients in group B,the MMPs levels in group A at 24、48 and 72 h after the operation were significantly lower.The patients in group A had lower levels of NT-proBNP and NE both at 48 h and 72 h after the operation.Lower levels of TNF-α and CRP were also found at 24 h and 48 h in this group.The MODS score at the fifth 、tenth and 15th day after the surgery were both significantly lower than that of the first day in patients of group A.Conclusion Dexmedetomidine can inhibit the inflammatory response during the aortic dissection perioperative period and can reduce the acute injury of organs caused by the excessive systemic inflammatory response.

Objective To test the hypothesis that interleukin-18 (IL-18) in the urine and serum sample are early biomarker for acute kidney injury (AKI) in patients after coronary artery bypass graft surgery (CABG).Methods Eighty patients who underwent CABG were recruited.The patients were divided into AKI group and non-AKI group according to the AKI criteria.The urine and serum sample were collected at pre-operation and 2 h,4 h,6 h,8 h,12 h,24 h after the CABG.The urine and serum IL-18 value were test by ELISA method.Receiver-operating characteristic cue(ORC) and the area under the cure(AUC) asses the sensitivity and specificity of IL-18 for AKI.Results Thirteen of eighty cases(16.25％) developed postoperative AKI according to the AKI criteria.Diagnosis with creatinine was only 24-48 hours after CABG.The serum and urinary concentrations of IL-18 at mostly each time point after CABG in AKI patients were significantly higher than those in non-AKI patients(P ＜ 0.01).Urinary and serous concentrations of IL-18 peaked at 4 h after CABG in AKI patients.ROC curve showed AUC in urinary and serous concentrations of IL-18 at 2 h ＞ 0.8 ; Concentrations of IL-18 in urine and serum at 2 h were the powerful independent predictors of AKI by logistic regression analysis.Conclusion IL-18 in urine and serum after CABG surgery were the powerful independent predictors of AKI.

Objective To examine the association of urinary neutrophil gelatinase-associated lipocalin(NGAL) and interleukin 18(IL-18) with acute kidney injury (AKI) in patients after cardiac surgery. Methods Thirty-three patients undergone cardiac surgery were divided into AKI group and non-AKI group according to the AKI criteria. The Scr, urinary NGAL and IL-18 were measured at different time points. Results Nine of 33 patients (27.27%)developed postoperative AKI, and Scr concentration in AKI group reached its peak within 12-48 hours after cardiac surgery. Urinary concentrations of NGAL and IL-18 at 2 h and 4 h after cardiac surgery were significantly higher than those before operation in AKI patients (P<0.01). The urinary concentrations of NGAL at each time point and that of IL-18 at 2 h and 4 h after cardiac surgery in AKI patients were significantly higher than those in non-AKI patients. After correction by urinary creatinine, the differences of NGAL/Ucr and IL-18/Ucr ratios were still significant (P< 0.01). For concentrations of urinary NGAL, IL-18 and ratios of NGAL/Ucr, IL-18/Ucr at 2 h after surgery, sensitivities and specificities were good with cutoff values at 250 μg/L, 250 μg/mmol and 1800 ng/L, 1800 ng/mmol, respectively. Urinary concentration of NGAL at 2 h after cardiac surgery was positively correlated with Scr at 12 h postoperation in AKI group (r=0.638, P<0.05).Conclusions The incidence of AKI in patients after cardiac surgery is quite high. Urinary concentrations of NGAL, IL-18 and ratios of NGAL/Ucr, IL-18/Ucr at 2 h after cardiac surgery are the early diagnostic markers for AKI, among which urinary NGAL/Ucr is the most sensitive one.

Objective To investigate the effects and mechanisms of carbon monoxide-releasing molecule-2 (CORM-2) on LPS induced barrier injure of Caco-2 cells.Methods The model of Caco-2 monolayer cells damage induced by LPS was established by using 50 &mu;g/ml LPS for 24 hours.After preconditioning with different concentrations (10 &mu;mol/L,50 &mu;mol/L,and 100 &mu; mol/L) of CORM-2 for 1 hour,the cultured well-grown Caco-2 monolayer cells were stimulated with 50 &mu; g/ml lipopolysaccharides (LPS) for 24 hour.The 100 &mu;mol/L CORM-2 was put into 37℃ and 5％ CO2 incubator for 18 hours until the CO has been fully released,and it became an inactive CORM-2(iCORM-2).The cultured Caco-2 monolayer cells were divided into six groups:the control group,the LPS group,the LC1(10 &mu;mol /L CORM-2 preconditioning) group,the LC2(50 &mu;mol/L CORM-2 preconditioning) group,the LC3(100 &mu;mol/L CORM-2 preconditioning) group,and the LC4 (iCORM-2 preconditioning) group.The apoptosis rates of different groups of Caco-2 monolayer cells were detected using flow cytometry.Cytokines (TNF-α,IL-1β and HMGB-1) levels of different groups were detected using ELISA kits.The levels of tight junction proteins (occludin ZO-1,claudin-1 and claudin-4) of every group were detected using Western blotting with specific antibodies.The structural changes of tight junction proteins were visualized by immunofluorescence technique.Results Compared with control group,cell apoptosis rate and release of inflammatory cytokines such as TNF-α,IL-1β and HMGB-1 in LPS group were significantly higher,and the levels of tight junction proteins were apparently decreased (P＜0.05) in LPS group.Compared with LPS group,cell apoptosis rate and release of inflammatory cytokines such as TNF-α,IL-1β and HMGB-1 decreased,and the levels of tight junction proteins were attenuated obviously,P＜0.05,in CORM-2 preconditioning groups.And the higher the concentration of CORM-2,the more obvious the protective effects.Conclusions This study demonstrates that CORM-2,as one of exogenous CO-releasing molecules,has the capacity to protect the barrier damage of LPS-stimulated Caco-2 monolayer cells in a concentration dependent manner.The higher the concentration of CORM-2 was,the stronger the protective effects were.The protective effects of CORM-2 include reducing Caco-2 monolayer cells apoptosis rate,inhibiting inflammatory cytokines production and release,and restoring distribution and levels of tight junction proteins.

Objective The effect of left atrial (LA) dimension on the occurrence of atrial fibrillation (AF) has been examined in some small studies.Less is known about the relationship of LA dimension,hemodynamic with AF during echocardiographic evaluation,especially,the flow dynamics in LA poorly described.The objective of this study was to investigate the relationship between LA dimension and the occurrence of AE Methods Two hundred and forty-five consecutive patients with heart disease scheduled to undergo open heart surgery were prospectively enrolled in the study.Patients were divided into 2 groups according to atrial fibrillation:AF group (n=148,99 men and 49 women,with a mean age 59.3+8.4 years),and no-AF group (n= 97,60 men and 37 womem).Echocardiography was performed before surgery.All measurements were performed following the American Society of Echocardiography recommendations.Results There were more patients with congestive heart failure in AF group than in no-AF group (45.9% vs 39.1%,P ＜0.05).The mean LA volume was 49.2±12.2 ml/m2 in AF group and 33.1±10.8 ml/m2 in no-AF group.There were also significant differences between two groups in left atrial end systolic dimension (LAESD) (50±13mm vs 27±14mm),left atrial end diastolic dimension (LAEDD) (79±17mm vs 53±13mm),PA pressure ( 41.3+11.6 mmHg vs 37.5±10.4 mmHg),and ratio of mitral E velocity and septal mitral annulus motion velocity (E/E') .The percentage of abnormal diastolic function grades (DGF) was also higher in AF than in no-AF group (89.9% versus 59.8% );.Conclusion Atrial fibrillation is associated more frequently with an increased LA dimension and more severe atrial hemodynamics disorder.(J Geriatr Cardiol 2008;5:11-4)