Hyperprocalcitonemia in patients with perioperative myocardial infarction after cardiac surgery

OBJECTIVE: To describe and compare procalcitonin (PCT) concentrations after cardiac surgery in uncomplicated patients and in patients with perioperative myocardial infarction (PMI). DESIGN: Retrospective comparative study. SETTING: One university hospital. PATIENTS: Fifty-eight adult patients undergoing cardiac surgery. INTERVENTION: None. MEASUREMENTS AND MAIN RESULTS: In a first step, plasma PCT and C-reactive protein concentrations were measured preoperatively and until 72 hrs postoperatively in ten consecutive patients who underwent uncomplicated cardiac surgery. PCT concentrations increased progressively from the end of cardiopulmonary bypass (0.09 +/- 0.09 ng/mL), peaked at 24 hrs postoperatively (1.14 +/- 1.24 ng/mL), and began to decrease at 48 hrs. C-reactive protein appeared to peak at 48 hrs (from 5.8 +/- 11.7 mg/L preoperatively to 265.1 +/- 103.5 mg/L on the second postoperative day). In a second step, PCT concentrations were measured at day one in 23 patients (PMI group) who presented high postoperative plasma cardiac troponin I concentrations and were compared with PCT concentrations observed in 25 matched uncomplicated patients. All patients were free from infection. PCT in the PMI group was significantly higher than in the control group (27.1 +/- 63.2 vs. 2.0 +/- 2.4 ng/mL, respectively; p =.0053). CONCLUSION: Because high plasma concentrations of PCT were found in patients with PMI after cardiac surgery, it may be suggested that, in the early postoperative period, elevated plasma PCT concentrations should be interpreted with caution regarding infection diagnosis.     

诱导室颤间断阻断主动脉后的心肌酶与超微结构变化

目的：常规心肌保护采用主动脉阻断灌注晶体、冷血、温血停跳液,本文研究诱导室颤主动脉间断阻断技术在冠状动脉搭桥术中的心肌保护作用。方法：选取18例诱导室颤主动脉间断阻断冠脉搭桥术患者为观察组（室颤组）,同期10例心脏冷停跳换瓣病人为对照组。测定体外循环前、体外循环后30min、60min、90min、术后第1天及第2天血清心肌酶谱和肌钙蛋白水平,并取左室心肌标本作扫描电镜观察。结果：体外循环前室颤组心肌酶谱和肌钙蛋白水平高于对照组,术后两组均升高而且与主动脉阻断时间和体外循环时间呈正比。术后第1天心肌酶谱和肌钙蛋白水平达最高峰,对照组明显高于室颤组。术后第2天室颤组心肌酶谱和肌钙蛋白水平下降接近体外前水平,但对照组仍不能降至体外循环的前水平,而且为室颤组的两倍。心肌电镜扫描发现室颤组体外循环90min后心肌细胞轻度受损,而对照组心肌缺血60min后就有中度心肌细胞破坏。结论：诱导室颤间断阻断主动脉技术对于冠状动脉搭桥术是一种安全有效的心肌保护方法。     

Exhaled nitric oxide level decreases after cardiopulmonary bypass in adult patients

OBJECTIVE: To measure exhaled nitric oxide (NO) and compare it with lung function after cardiopulmonary bypass (CPB) in adult patients. Pulmonary dysfunction is sometimes observed after CPB. Impaired production of NO may account for this dysfunction. DESIGN: Prospective, single-center, observational study. SETTING: University hospital operating room, intensive care unit. PATIENTS: Sixteen adult patients undergoing cardiac surgery with CPB. INTERVENTIONS: None except cardiac surgery with CPB. MEASUREMENTS AND MAIN RESULTS: Exhaled NO was measured continuously by the chemiluminescence method and was expressed as the peak and mean NO concentrations, and the NO output (VNO). These parameters were calculated by averaging four sequential tidal NO values. The data were obtained serially from before CPB to 16 hrs after CPB. Lung function was evaluated by monitoring lung compliance, pulmonary artery pressure, and alveolar-arterial oxygen difference (P(A-a)O2). The cardiac index did not change except for a significant increase at 16 hrs compared with 6 hrs after CPB. Peak NO, mean NO, and VNO decreased from 15.4 +/- 2.0 ppb (before CPB) to 8.2 +/- 0.8 ppb (6 hrs after CPB), from 5.7 +/- 0.7 ppb to 2.8 +/- 0.6 ppb, and from 29.2 +/- 3.1 nL/min to 15.7 +/- 2.2 nL/min, respectively. These changes were associated with the increases in pulmonary artery pressure and alveolar-arterial oxygen difference, and the decrease in lung compliance. VNO recovered to the level measured before CPB 16 hrs after CPB, which was consistent with the physiologic recovery in pulmonary hypertension, lung compliance, and gas exchange. CONCLUSION: Measurement of exhaled NO as VNO, which was associated with lung dysfunction, may be an indicator of lung injury in adult patients after cardiopulmonary bypass.     

Effect of dexamethasone on postoperative cardiac troponin T production in pediatric cardiac surgery

Objective Pediatric cardiac surgery is associated with a temporary rise in cardiac troponin T (cTnT) during the postoperative period. We examined whether dexamethasone given before cardiopulmonary bypass has myocardial protective effects as assessed by the postoperative production of cTnT.Design and setting Prospective randomized interventional study in the pediatric intensive care unit in a university hospital.Interventions Patients were randomly allocated to act as controls or receive a single dose of dexamethasone (1 mg/kg) during induction of anesthesia.Measurements and results cTnT was measured four times postoperatively: immediately after admission to the pediatric intensive care unit (PICU) and 8, 15, and 24 h thereafter. The two groups had similar mean cTnT concentrations on PICU admission: those receiving dexamethasone 1.85 ng/ml (1.55–2.15) and those not receiving it 2 ng/ml (95% confidence interval 1.56–2.51). Concentrations of cTnT 8 h after admission to the PICU differed significantly after 8 h: 1.99 ng/ml (1.53–2.45) in those receiving dexamethasone and 3.08 ng/ml (2.46–3.69) in those not receiving it. After subgroup statistical analysis differences between the two groups remained significant only at 8 h, not those after 15 or 24 h.Conclusions The use of dexamethasone (1 mg/kg) before cardiopulmonary bypass is associated with a brief but significant reduction in postoperative cTnT production. The clinical significance of this effect is unclear.     

Changes in biochemical and biophysical surfactant properties with cardiopulmonary bypass in children

OBJECTIVE: The aim of the present study was to characterize pulmonary surfactant properties in children undergoing cardiovascular surgery with cardiopulmonary bypass. DESIGN: Prospective clinical trial. SETTING: University hospital pediatric intensive care unit. PATIENTS: Fifty pediatric patients with congenital cardiac defects undergoing cardiovascular surgery with (n = 35) and without (n = 15) cardiopulmonary bypass procedure. INTERVENTIONS: Tracheal aspirates were collected by saline lavage during routine suctioning before (baseline) and after cardiopulmonary bypass, as well as 4, 8, and 24 hrs after admission to the pediatric intensive care unit. MEASUREMENTS AND MAIN RESULTS: Total protein and phospholipid concentrations were assessed in native tracheal aspirates, in large surfactant aggregates, and in small surfactant aggregates. Phospholipid profiles and phosphatidylcholine fatty acids; surfactant apoproteins SP-A, SP-B, and SP-C (enzyme-linked immunosorbent assay); and surface activity (Pulsating Bubble Surfactometer) were all analyzed in large surfactant aggregates. With cardiopulmonary bypass, an initial increase in total protein content was followed by an increase in phospholipid concentration in tracheal aspirates. Large surfactant aggregates decreased 4 hrs after cardiopulmonary bypass (4 hrs, 22.6 +/- 5.6%; mean +/- SEM; p<.01 compared with baseline, 55.4 +/- 9.2%) but recovered within 24 hrs. The phospholipid-protein ratio of large surfactant aggregates 24 hrs after cardiopulmonary bypass (1.2 +/- 0.2; p<.01) was significantly decreased compared with baseline (2.9 +/- 0.6). The relative amount of phosphatidylglycerol content in the large surfactant aggregates-fraction dropped linearly over time but other phospholipids remained mainly unchanged. Phosphatidylcholine fatty acid profiles remained unaffected by cardiopulmonary bypass. The relative content of SP-B and SP-C in large surfactant aggregates increased approximately three-fold compared with baseline. Altogether, our findings with recovered large surfactant aggregate/small surfactant aggregate ratios and increased phospholipid in tracheal aspirates after 24 hrs represent an approximately ten-fold increase in large surfactant aggregate-associated SP-B and SP-C compared with baseline. Only minor changes were detected in biophysical properties of large surfactant aggregates throughout the observation period. CONCLUSIONS: Cardiopulmonary bypass procedure in children induces profound changes in the surfactant system involving both phospholipid and protein components; biophysical function may have been maintained by compensatory increase in SP-B and SP-C.     

Sex-based differences in serum cardiac troponin I,a specific marker for myocardial injury,after cardiac surgery

BACKGROUND: Prevalence and causes of sex-based differences in morbidity and mortality secondary to cardiovascular disease remain controversial. Cardiac troponin I (cTnI) is a sensitive and specific marker for myocardial injury. Serial cTnI measurements have been used to identify perioperative myocardial cell injury. OBJECTIVE: To determine whether sex influences the extent of myocardial injury during cardiac surgery, we measured perioperative cTnI in male and female patients. DESIGN: A total of 17 male and 17 female patients were prospectively studied in an age- and case-matched manner. Arterial cTnI were obtained preinduction, 30 mins after the application of the aortic cross-clamp, at arrival to the intensive care unit, and on postoperative day 1. SETTING: Tertiary cardiac surgery center at a major teaching hospital. RESULTS: There was no difference between men and women in body mass index (kg/m2), duration of cardiopulmonary bypass, and aortic cross-clamp times. Preoperative cTnI measurements were similar in men (0.24 +/- 0.15 ng/mL) and women (0.25 +/- 0.13 ng/mL, mean +/- sem). The maximum serum cTnI occurred on postoperative day 1 in all patients, and it was 3-fold higher in men (18.5 +/- 5.7 ng/mL) compared with women (6.4 +/- 1.0 ng/mL). CONCLUSIONS: Men had markedly higher serum cTnI compared with women, although they were case matched with respect to age and cardiac risk factors. Our results may suggest there may be sex-related differences in the myocardial response to ischemia and reperfusion injury or intrinsic differences between the male and female myocardium.     

Plasma brain natriuretic peptide and cardiac troponin I concentrations after adult cardiac surgery: association with postoperative cardiac dysfunction and 1-year mortality

OBJECTIVE: The purpose of the present study was to evaluate the prognostic implications of perioperative B-type natriuretic peptide (BNP) and cardiac troponin I concentrations in patients undergoing cardiopulmonary bypass for cardiac surgery. DESIGN: Prospective observational study. SETTING: Biochemistry laboratory and surgical care unit in a university hospital. PATIENTS: A total of 92 consecutive patients undergoing elective coronary artery (43 patients) or valve surgery (49 patients). INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: BNP and cardiac troponin I concentrations were measured before surgery (day 0), and at day 1 after surgery. Postoperative cardiac dysfunction was defined as low cardiac output or hemodynamic instability requiring inotropic support for >24 hrs or congestive heart failure until day 5. One-year survival was also evaluated. Univariate and multivariate analyses were performed. An important BNP secretion was systematically observed after cardiac surgery. Independent predictors of cardiac dysfunction were preoperative New York Health Association class and BNP and cardiac troponin I concentrations measured at day 1. Patients with an elevation of both markers have a 12-fold increased risk of postoperative heart failure. The use of both markers in combination predicted better postoperative heart failure than each one separately. Age, low preoperative left ventricular ejection fraction, and elevated BNP at day 1 (>352 pg/mL) were associated with an increased mortality rate at 1 yr. In multivariate analysis, only left ventricular ejection fraction was significantly associated with 1-yr survival. CONCLUSIONS: Postoperative plasma BNP and cardiac troponin I levels are independent predictors of postoperative cardiac dysfunction after cardiac surgery. Simultaneous measurement of BNP and cardiac troponin I improve the risk assessment of postoperative cardiac dysfunction. However, the association between BNP levels and 1-yr outcome was no longer significant after adjustment on left ventricular ejection fraction.     

Low systemic vascular resistance state in patients undergoing cardiopulmonary bypass.

OBJECTIVE: To determine the prevalence, hemodynamic characteristics, and risk factors for the low systemic vascular resistance (SVR) state in patients who have undergone cardiopulmonary bypass. DESIGN: Prospective cohort study. SETTING: The intensive care unit of a tertiary care hospital. PATIENTS: Seventy-nine consecutive patients who underwent coronary artery bypass graft, mitral valve, or aortic valve procedures. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Low SVR was defined as an indexed systemic vascular resistance (SVRi) of <1800 dyne x sec/cm5 x m2 at two consecutive times postoperatively. SVRi, cardiac index, mean arterial pressure, temperature, and central venous pressure were recorded before bypass and at 0, 1, 2, 4, 8, and 16 hrs after bypass. We recorded age, gender, urgency of operation, use of angiotensin-converting enzyme inhibitors and calcium channel blockers, ejection fraction, pump time, cross-clamp time, use of antifibrinolytics, type of oxygenator, amrinone use, postoperative biochemical and hematologic values, medication use, fluid balance, intensive care unit admission duration, and hospital admission duration. We assessed the role of diabetes mellitus, current smoking, and systemic hypertension. The incidence of the low-SVR state was 35 of 79 patients during a 3-month period (44%). At 8 hrs postoperatively, the SVRi in low-SVR and non-low-SVR patients was 1594+/-50 (SEM) and 2103+/-56 (SEM) dyne x sec/cm5 x m2, respectively (p < .001). In low-SVR patients, there was an initial and sustained increase in cardiac index and central venous pressure that preceded the decrease in mean arterial pressure. The decrease in mean arterial pressure was maximal at 8 hrs postoperatively. Patients with low SVR were more likely to have longer cross-clamp times, to be male, and to have lower postoperative platelet counts (p < .05 for all). Low-SVR patients were less likely to require dobutamine in the first 4 hrs postoperatively. CONCLUSIONS: Low SVR, a probable manifestation of systemic inflammatory response syndrome, is common in patients after cardiopulmonary bypass. These patients may respond better to a vasopressor to restore vascular tone than to volume loading to further increase cardiac index.     

Penetration of vancomycin in uninfected sternal bone.

Concentrations of vancomycin in sternal bones of 10 patients undergoing cardiac surgery were studied at steady state, 48 h after starting intravenous prophylaxis. A sample of sternal bone was taken before (group I) or after (group II) cardiopulmonary bypass. The mean vancomycin concentrations in sternal bones were not significantly different between the groups and were 9.3 +/- 3.0 micrograms/g. The concentrations of vancomycin in sternal bones were always above the MICs for staphylococci, streptococci, and enterococci.     

Leukocyte filtration in the early reperfusion phase on cardiopulmonary bypass reduces myocardial injury

Improved myocardial protection and cardiopulmonary bypass (CPB) have limited, but not abolished, intraoperative myocardial damage due to surgical reperfusion injury after release of the aortic crossclamp. In this double-blind, randomized study, we evaluated whether short-term leukocyte filtration during reperfusion may further reduce myocardial damage. Thirty-eight patients with coronary artery disease were randomly assigned to CPB with (group I; n = 19) or without leukocyte filtration (group II; n = 19). There was no difference in bypass time or crossclamp time between the groups. No patient in group I required catecholamines, whereas three patients in group II were supported with adrenaline or dobutamine on the first and second postoperative day. In addition, troponin T plasma levels were lower in group I (p < 0.05), whereas other markers for tissue injury (CK, CK-MB, LDH, S-GOT and S100B) did not differ. In conclusion, leukocyte filtration during reperfusion may further improve CPB by reducing myocardial damage.     

Myocardial inflammatory activation in children with congenital heart disease

OBJECTIVE: In several cardiac-related diseases, there is a strong association between systemic endotoxemia, myocardial cytokine production, and cardiac failure. Because pre- and postoperative endotoxemia recently was reported in children with congenital heart disease, we sought direct evidence of myocardial inflammatory activation in a cohort of children undergoing congenital heart surgery on cardiopulmonary bypass. Inflammatory activation was prospectively defined as the presence of nuclear factor-kappaB nuclear translocation in myocardial tissue samples. DESIGN: Prospective observational study. SETTING: Tertiary care pediatric intensive care unit. PATIENTS: Fifteen children with congenital heart disease undergoing operative repair on cardiopulmonary bypass. INTERVENTIONS: All patients underwent operative repair of congenital heart disease on cardiopulmonary bypass and had plasma samples obtained for endotoxin and tumor necrosis factor-alpha, both pre- and postoperatively. Myocardial tissue samples were obtained intraoperatively, both before and during cardiopulmonary bypass. MEASUREMENTS AND MAIN RESULTS: Elevated plasma endotoxin concentrations were documented in all 15 patients during the study period. In 12 patients, plasma endotoxin was elevated before cardiopulmonary bypass. The median preoperative tumor necrosis factor-alpha concentration was 16.4 pg/mL, which is higher than concentrations reported in adults with New York Heart Association class III congestive heart failure. Examination of myocardial tissue samples revealed nuclear factor-kappaB nuclear translocation (predominantly p50/p65 heterodimers) in nine of 15 patients (60%). Four of these nine patients had nuclear factor-kappaB nuclear translocation before initiation of cardiopulmonary bypass, with p50/p50 homodimers present in two of the four. CONCLUSIONS: These data provide the first evidence of nuclear factor-kappaB activation in children with congenital heart disease and the first evidence of myocardial nuclear factor-kappaB translocation in human hearts before explant for transplantation. Furthermore, these data suggest that, similar to adults with advanced congestive heart failure, the myocardial inflammatory cascade may contribute to the pathophysiology of congenital heart disease in infants and children.     

Interleukin-10 and its role in clinical immunoparalysis following pediatric cardiac surgery

OBJECTIVE: A systemic insult is associated with subsequent hyporesponsiveness to endotoxin (as measured by ex vivo tumor necrosis factor [TNF]-alpha production) and an increased risk of late nosocomial infection in some patients. When combined with low monocyte surface major histocompatibility complex class II expression, this state of altered host defense is now commonly referred to as immunoparalysis. This study was undertaken to delineate the relationship between observed levels of the anti-inflammatory cytokine interleukin-10, common genetic polymorphisms that influence these levels, and the occurrence and severity of endotoxin hyporesponsiveness in children following elective cardiac surgery requiring cardiopulmonary bypass. DESIGN: A prospective observational clinical study. SETTING: A tertiary pediatric cardiac center. PATIENTS: Thirty-six infants and children <2 yrs of age undergoing elective cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We investigated the production of TNF-alpha, interleukin-6, interleukin-8, interleukin-1 receptor antagonist, and interleukin-10 in whole blood in response to lipopolysaccharide (Neisseria meningitides 10 ng/mL) in samples drawn before, during, and up to 48 hrs after surgery. Patients were genotyped for the -1082, -819, and -592 interleukin-10 promoter polymorphisms. Whole blood cytokine response to lipopolysaccharide was reduced postoperatively to 100 pg/mL) over the first 48 hrs were more likely to have an uncomplicated short stay (odds ratio 4.7, 95% confidence interval 1-22). CONCLUSIONS: Immediately following cardiac surgery, many children become relatively refractory to lipopolysaccharide stimulation. This immunoparalysis appears to be related in part to high circulating levels of interleukin-10 and places these patients at increased risk of postoperative complications. Interleukin-10 genotype may be a risk factor for immunoparalysis.     

Effects of ulinastatin treatment on the cardiopulmonary bypass-induced hemodynamic instability and pulmonary dysfunction

OBJECTIVE: To examine the association between decreased release of proinflammatory cytokines in response to urinary trypsin inhibitor pretreatment and decreased myocardial and lung injury after cardiopulmonary bypass. DESIGN: A prospective, randomized, double-blind study. SETTING: University hospital. SUBJECTS: Thirty patients on cardiopulmonary bypass undergoing coronary artery bypass grafting. INTERVENTIONS: Patients received 5000 units/kg intravenous urinary trypsin inhibitor (n = 15) or 0.9% saline (control, n = 15) immediately before aortic cannulation for cardiopulmonary bypass. MEASUREMENT AND MAIN RESULTS: Neutrophil elastase, tumor necrosis factor-alpha, interleukin-6, and interleukin-8 were measured after intubation (T1), immediately before aortic cannulation (T2), after separation from cardiopulmonary bypass (T3), at the end of surgery (T4), and on postoperative days 1 (T5), 3 (T6), and 5 (T7). Simultaneous hematocrit values were obtained at all sample times. Isoenzyme of creatine kinase with muscle and brain subunits, troponin-T, and myosin light chain I were also measured. Various hemodynamic and pulmonary data were obtained perioperatively. Levels of neutrophil elastase and cytokines were corrected for hemodilution. Interleukin-6 and interleukin-8 levels were lower at T3 and T4 in the urinary trypsin inhibitor group than in the control group. Stroke volume index was significantly decreased in the control group at T3, and statistical difference was found between groups at T3 (p < .01). Respiratory index and intrapulmonary shunt were significantly higher in the control group than in the urinary trypsin inhibitor group at T3. Changes in respiratory index and intrapulmonary shunt correlated with interleukin-8 levels at T3 (r = .52, p < 00001; r = .37, p < 0001, respectively) and T4 (r = .44, p < .001; r = .24, p < .05, respectively). Neutrophil elastase levels and cardiac marker responses to coronary artery bypass grafting surgery were similar in both groups. CONCLUSIONS: Prepump administration of urinary trypsin inhibitor attenuates the elevation of interleukin-6 and interleukin-8 release immediately after cardiopulmonary bypass.     

Evaluation of the effect of one large dose of erythropoietin against cardiac and cerebral ischemic injury occurring during cardiac surgery with cardiopulmonary bypass: a randomized double-blind placebo-controlled pilot study

Cardiac surgery and cardiopulmonary bypass (CPB) induce ischemia–reperfusion and subsequent cellular injury with inflammatory reaction. Clinical and experimental studies suggest that recombinant human erythropoietin (EPO) independently of its erythropoietic effect may be used as a cytoprotective agent against ischemic injury. We tested the hypothesis that one large dose of EPO administered shortly before CPB prevents the elevation of cardiac and cerebral ischemic blood markers as well as the systemic inflammatory response induced by cardiac surgery with CBP through this randomized double‐blind placebo‐controlled pilot trial. Fifty patients scheduled for coronary artery bypass graft (CABG) surgery with CPB were randomly allocated to EPO or control groups. EPO (800 IU/kg intravenously) or placebo (saline) was administered before CPB. The primary end point was to study the effect of EPO administration on several blood markers of myocardial and cerebral ischemia in relation to CABG with CPB. In both groups, surgery increased plasma concentrations of cardiac (troponin T, NT‐proBNP, and creatine kinase MB) and cerebral (S100β protein) markers ischemic as well as the pro‐inflammatory marker interleukin‐6. Compared with the placebo, EPO administration before CPB did not prevent an increase of all these markers following CPB. In conclusion, one large dose of EPO, given shortly before CPB, did not protect against cardiac and cerebral ischemia and inflammatory response occurring during CABG surgery with CPB. Although the long‐term clinical implications remain unknown, the findings do not support use of EPO at this dose as a cytoprotective agent in patients undergoing cardiac surgery.     

Synergy of isoflurane preconditioning and propofol postconditioning reduces myocardial reperfusion injury in patients

Either isoflurane preconditioning or high-dose propofol treatment has been shown to attenuate myocardial IRI (ischaemia/reperfusion injury) in patients undergoing CABG (coronary artery bypass graft) surgery. It is unknown whether isoflurane and propofol may synergistically attenuate myocardial injury in patients. The present study investigated the efficacy of IsoPC (isoflurane preconditioning), propofol treatment (postconditioning) and their synergy in attenuating postischaemic myocardial injury in patients undergoing CABG surgery using CPB (cardiopulmonary bypass). Patients (n = 120) selected for CABG surgery were randomly assigned to one of four groups (n = 30 each). After induction, anaesthesia was maintained either with fentanyl and midazolam (control; group C); with propofol at 100 μg x kg(-1) of body weight x min(-1) before and during CPB followed by propofol at 60 μg x kg(-1) of body weight x min(-1) for 15 min after aortic declamping (group P); with isoflurane 1-1.5% end tidal throughout the surgery (group I) or with isoflurane 1-1.5% end tidal before CPB and switching to propofol at 100 μg x kg(-1) of body weight x min(-1) during CPB followed by propofol at 60 μg x kg(-1) of body weight x min(-1) for 15 min after aortic declamping (group IP, i.e. IsoPC plus propofol postconditioning). A joint isoflurane and propofol anaesthesia regimen synergistically reduced plasma levels of cTnI (cardiac troponin I) and CK-MB (creatine kinase MB) and f-FABP (heart-type fatty acid-binding protein) (all P < 0.05 compared with control, group P or group I) and facilitated postoperative myocardial functional recovery. During reperfusion, myocardial tissue eNOS (endothelial NO synthase) protein expression in group IP was significantly higher, whereas nitrotyrosine protein expression was lower than those in the control group. In conclusion, a joint isoflurane preconditioning and propofol anaesthesia regimen synergistically attenuated myocardial reperfusion injury in patients.     

Effects of atorvastatin on systemic inflammatory response after coronary bypass surgery

OBJECTIVES: Systemic inflammatory response occurs frequently after coronary artery bypass surgery, and it is strongly correlated with the risk of postoperative morbidity and mortality. Recent studies demonstrate that treatment with statin is associated with a significant and marked decrease in inflammation-associated variables such as the C-reactive protein, cytokines, and adhesion molecules. Therefore, we investigated the effects of preoperative atorvastatin treatment on systemic inflammatory response and perioperative morbidity after cardiopulmonary bypass. DESIGN: Double-blinded, placebo-controlled, randomized study. SETTING: University hospital. PATIENTS: Forty patients were randomized to treatment with atorvastatin (20 mg/day, group A, n=20) or placebo (group B, n=20) 3 wks before surgery. INTERVENTIONS: Three-week treatment by atorvastatin 20 mg/day. MEASUREMENT AND MAIN RESULTS: Postoperative serum levels of both interleukin-6 and interleukin-8 increased significantly over baseline, but the peak levels observed 4 hrs postoperatively were significantly lower in the atorvastatin group. In the same fashion, CD11b expression on neutrophils was significantly lower in the statin group at 4 and 24 hrs postoperatively. Finally, neutrophil-endothelial adhesion was significantly reduced in the statin patients compared with controls. The operation time, blood loss, need for inotropic support, intubation time, and length of intensive care unit or hospital stay did not differ significantly between the two groups. The systemic inflammatory response syndrome score on postoperative days 1 and 2 was comparable in both groups. CONCLUSIONS: Pretreatment with atorvastatin significantly reduces cytokine release and neutrophil adhesion to the venous endothelium in patients undergoing coronary artery bypass grafting with cardiopulmonary bypass.     

紫外线照射充氧自体血心脏停搏液对犬体外循环手术时心肌线粒体的影响

目的 研究紫外线照射充氧自体血（UBIO）心脏停搏液对犬体外循环（CPB）心内直视手术时心肌线粒体的影响。 方法 选取20只雄性杂交犬,按随机数字表法将其分为对照组和UBIO心脏停搏液组（UBIO组）,每组10只。建立犬CPB心内直视手术模型,CPB中对照组使用普通含血心脏停搏液,实验组采用UBIO心脏停搏液。在阻断升主动脉前和开放升主动脉后,分别从冠状静脉窦取血,检测血清心肌肌钙蛋白I(cTnI)和肌酸激酶同工酶(CK-MB)水平。在打开和关闭右心房时,分别取右心房组织标本,采用化学比色法检测组织匀浆线粒体超氧化物歧化酶（SOD）活性、谷胱甘肽过氧化物酶（GSH-Px）活性及丙二醛（MDA）含量,同时测定心肌线粒体膨胀度。 结果 阻断升主动脉前,2组犬cTnI、CK-MB含量之间比较,差异无统计学意义（P>0.05）。在开放升主动脉后,对照组cTnI、CK-MB含量高于UBIO组,差异有统计学意义（P<0.05)。打开右心房时,2组犬心肌组织匀浆SOD活性、GSH-Px活性和MDA含量之间比较,差异无统计学意义（P>0.05）。关闭右心房时,2组犬心肌组织匀浆SOD活性、GSH-Px活性低于打开右心房时的SOD活性、GSH-Px活性（P<0.05）。2组犬关闭右心房时的MDA含量均高于组内打开右心房时的MDA含量（P<0.05)。关闭右心房时,UBIO组心肌组织匀浆SOD活性［（34.1±5.1）KNU/g］、GSH-Px活性［（44.2±7.4）kat/g］高于对照组SOD活性［（20.5±4.3）KNU/g］、GSH-Px活性［（32.7±6.3）kat/g］,MDA含量［（6.9±1.2）mol/L］低于对照组［（9.5±1.9）mol/L］（P<0.05)。UBIO组线粒体膨胀度改变较小。 结论 CPB心内直视手术时存在心肌线粒体清除氧自由基能力下降及线粒体本身脂质过氧化反应,UBIO心脏停搏液可以保持线粒体清除氧自由基的能力,并减轻线粒体本身的受攻击程度,较好地维持线粒体结构与功能,减轻心肌损伤。     

Cardiac troponin T for prediction of short- and long-term morbidity and mortality after elective open heart surgery

BACKGROUND: Increased cardiac troponins in blood are observed after virtually every open heart surgery, indicating perioperative myocardial cell injury. We sought to determine the optimum time point for blood sampling and the respective cutoff value of cardiac troponin T (cTnT) for risk assessment in patients undergoing cardiac surgery. METHODS: In a series of 204 patients undergoing scheduled open heart surgery, mainly for coronary artery bypass grafting (n = 132) or valve repair (n = 27), cTnT concentrations were measured before and 4 and 8 h after cross-clamping and then daily for 7 days. Individual risk was assessed by use of the Cleveland Clinic Foundation Risk score and intraoperative risk indicators such as duration of cardiopulmonary bypass, cross-clamping, and perioperative release of cardiac markers. Patients were followed for 28 months. RESULTS: Cardiac mortality, all-cause mortality rates, and rates of nonfatal acute myocardial infarction (AMI) at 28 months were 6.9%, 8.8%, and 6.8%, respectively. cTnT was higher in patients with Q-wave AMI or postoperative heart failure requiring inotropic support, and in nonsurvivors. The ROC curve revealed a cTnT > or = 0.46 microg/L at 48 h as the optimum discriminator for long-term cardiac mortality. Stepwise logistic regression identified higher Cleveland Clinic Risk Score [odds ratio (OR) = 2.6 per point], cross-clamp time >65 min (OR = 6.6), and cTnT (OR = 4.9) as significant and independent predictors of long-term cardiac mortality. CONCLUSIONS: A single postoperative cTnT measurement can be used to estimate myocardial cell injury that impacts long-term survival after open heart surgery. It adds independently to established risk indicators.     

Stress doses of hydrocortisone reduce severe systemic inflammatory response syndrome and improve early outcome in a risk group of patients after cardiac surgery

OBJECTIVE: Severe systemic inflammation with a vasodilatory syndrome occurs in about one third of all patients after cardiac surgery with cardiopulmonary bypass. Hydrocortisone has been used successfully to reverse vasodilation in septic patients. We evaluated if stress doses of hydrocortisone attenuate severe systemic inflammatory response syndrome in a predefined risk group of patients after cardiac surgery with cardiopulmonary bypass. DESIGN: Randomized, nonblinded, controlled trial. SETTING: Anesthesiologic intensive care unit for cardiac surgical patients of an university hospital. PATIENTS: After a risk analysis, we enrolled 91 patients into a prospective randomized trial. Patients were included according to the evaluated criteria (preoperative ejection fraction, duration of cardiopulmonary bypass, type of surgery). INTERVENTIONS: The treatment group received stress doses of hydrocortisone perioperatively: 100 mg before induction of anesthesia, then 10 mg/hr for 24 hrs, 5 mg/hr for 24 hrs, 3 x 20 mg/day, and 3 x 10 mg/day. MEASUREMENTS AND MAIN RESULTS: We measured various laboratory (e.g., lactate) and clinical variables (e.g., duration of ventilation and length of stay in the intensive care unit), characterizing the patients' outcome. The two study groups did not differ regarding age, preoperative medication, duration of the cardiopulmonary bypass, and type of surgery. The patients in the treatment group had significantly lower concentrations of IL-6 and lactate, higher antithrombin III concentration, lower need for circulatory and ventilatory support and for transfusions, lower Therapeutic Intervention Scoring System values, and shorter length of stay in the intensive care unit and in the hospital. The mortality rate did not differ significantly between the groups. CONCLUSIONS: Although we acknowledge the limitations of a nonblinded interventional trial, stress doses of hydrocortisone seem to attenuate systemic inflammation in a predefined risk group of patients after cardiac surgery with cardiopulmonary bypass and improve early outcome.