冠状动脉旁路移植手术围术期血清肌钙蛋白T水平的变化

目的 探讨肌钙旧白Ｔ作为心肌损伤生化樗物的价值。方法 连续选择冠状动脉旁路移植手术（ＣＡＢＧ）患者２２例，分别于麻醉前、体外循环（ＣＰＢ）前、ＣＰＢ结束后即刻和ＣＰＢ后２４小时，抽取静脉血４ｍｌ，用于肌酸激酶（ＣＫ）、肌酸激酶－ＭＢ（ＣＫ－ＭＢ）和心肌肌钙蛋白Ｔ（ｃＴｎＴ）的测定。结果 ＣＰＢ前ＣＫ、ＣＫ－ＭＢ和ｃＴｎＴ的中位数皆在正常范围内，ＣＰＢ后即刻和２４均显著性增高，ＣＫ以术后２４小时最为     

右美托咪定对心肺转流下冠状动脉旁路移植术后心脏同步化运动的影响

目的 探讨右美托咪定对心肺转流(CPB)下行冠状动脉旁路移植术(CABG)患者心脏同步化运动的影响.方法 择期CPB下行CABG患者24例,年龄43～75岁,体表面积1.53～2.00m2,ASAⅡ或Ⅲ级,心功能Ⅱ或Ⅲ级.采用随机数字表法分为两组:右美托咪定组(D组)和对照组(C组),每组12例.两组术中麻醉维持均采用全凭静脉麻醉,D组于主动脉开放后经微量注射泵静注右美托咪定负荷剂量0.5μg/kg(10 min内注射完),然后以0.5 μg·kg-1·h-1维持给药至术毕,C组静注等量生理盐水.分别于开胸前(T1)和CPB停机后30 min(T2)、60 min(T3)记录血流动力学指标:HR、MAP、CVP、心脏指数(CI),左右心室收缩功能指标:左室射血分数(LVEF)、右室射血分数(RVEF)和心脏同步性参数:PR间期、QRS时限、室间机械延迟(IVMD).结果 与T1时比较,T2、T3时两组HR明显增快、CI明显升高(P＜0.01);与C组比较,D组T2、T3时PR间期明显延长(P＜0.05).两组间QRS时限及IVMD差异无统计学意义.结论 CPB下冠状动脉旁路移植术患者,右美托咪定负荷剂量0.5μg/kg后以0.5μg· kg-1·h-1维持能够延长PR间期,影响房室间同步化运动,但对左右心室间电机械同步化运动无明显影响.     

Perturbations in laboratory values after coronary artery bypass graft surgery with cardiopulmonary bypass

OBJECTIVE: The purpose of this study was to describe the sequential changes in commonly obtained laboratory values after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). METHODS: The authors examined laboratory data from 375 patients who underwent uncomplicated CABG with CPB in a multicenter clinical trial of a medication for postoperative pain. Data were obtained preoperatively, at the time of postoperative extubation, and at 4 subsequent intervals ending 14 days after extubation. Data obtained before study drug administration are reported for all patients; thereafter, only data from placebo patients without perioperative complications (n=123) are reported. RESULTS: Mean postoperative coagulation values remained within their reference ranges at the time of extubation. However, platelet counts increased to a peak value well above the reference range by the end of the study. Postoperative white blood cell counts rose above the reference range, mainly because of increased neutrophils. Serum chemistries were also altered; most patients showed a persistent postoperative hyperglycemia. Creatine kinase levels rose to nearly 4 times the upper limit of the reference range in the early postoperative period. Lactate dehydrogenase, serum aspartate aminotransferase, and alanine aminotransferase levels also increased above the reference range. Total protein and albumin values were below the reference range throughout the postoperative period. CONCLUSIONS: Laboratory values for hematology, blood coagulation, and serum chemistry change substantially after uncomplicated CABG with CPB. Recognition of these changes will facilitate the conduct of clinical research and may prevent inappropriate treatment based on abnormal laboratory findings that have no clinical significance.     

Risk stratification with cardiac troponin I in patients undergoing elective coronary artery bypass surgery.

OBJECTIVE: Cardiac troponin I (cTnI) is a highly sensitive and specific marker for postoperative prediction of patients outcome after coronary artery bypass surgery (CABG). Whether preoperatively elevated cTnI levels similarly predict the outcome in patients scheduled for elective CABG is currently unknown. METHODS: Therefore, a possible correlation between preoperative cTnI levels and perioperative major adverse events and in-hospital mortality after CABG was investigated. CTnI was measured within 24h before surgery in 1405 out of 3124 consecutive elective CABG patients. Out of these patients, 1178 had a preoperative cTnI level below 0.1ng/ml (group 1), 163 patients had a cTnI level between 0.11 and 1.5ng/ml (group 2), and 64 patients had a cTnI level above 1.5ng/ml (group 3). CTnI levels, electrocardiograms, clinical data, adverse events and in-hospital mortality were recorded prospectively. Patients with ST-elevation myocardial infarction less than 7 days before surgery were excluded from the study. RESULTS: Perioperative myocardial infarction (PMI) occurred in 69/1178 patients (5.9%) in group 1, 14/163 patients (8.6%; odds ratio (OR) 1.5, 95% confidence interval (CI): 0.8-2.8) in group 2, and 11/64 patients (17.2%; OR 3.3, CI: 1.6-7.0) in group 3 (overall: P<0.001, Cochran-Armitage trend test). Low cardiac output syndrome (LCOS) occurred in 19/1178 patients (1.6%), 9/163 (5.5%; OR 3.6, CI: 1.5-8.5), and 7/64 patients (10.9%; OR 7.5, CI: 2.7-19.8) (overall: P<0.001, group 1 vs. group 2: P<0.002), respectively. In-hospital mortality was 1.7% in group 1 and 3.1% in group 2, but 6.3% (OR 3.9, CI: 1.1-12.5) in group 3 (overall: P<0.01, group 1 vs. group 2: P=NS). Intensive care and hospital stay were significantly longer in group 3 compared to groups 1 and 2. Univariate and multivariate logistic regression analysis confirmed the statistically significant relationship between cTnI and PMI, LCOS and in-hospital mortality, respectively (P<0.001). CONCLUSIONS: Risk stratification by measurement of cTnI levels within 24h before elective CABG clearly identifies a subgroup of patients with increased risk for postoperative adverse outcome and in-hospital mortality.     

Minor cardiac troponin T release in patients undergoing coronary artery bypass graft surgery on a beating heart

OBJECTIVES: To determine whether and to what extent coronary artery bypass graft (CABG) surgery without extracorporeal circulation is associated with cardiac troponin T (TnT) release. DESIGN: Prospective study. SETTING: A single university hospital. PARTICIPANTS: Twenty-three patients scheduled for minimally invasive CABG surgery. Sixteen patients received one coronary anastomosis, and seven received two. INTERVENTIONS: TnT and creatine kinase-MB (CK-MB) levels were determined immediately before induction of anesthesia (baseline) and at 0, 12, and 24 hours after surgery. Hemodynamic measurements were made, and 5-lead electrocardiograms with continuous automated ST-segment trends were analyzed. MEASUREMENTS AND MAIN RESULTS: All patients had a good cardiac outcome. Median cumulative coronary artery occlusion time was 27 minutes (range, 10 to 49 minutes). TnT levels were undetectable in 91.3% of patients at baseline when a detection limit of 0.01 ng/mL was employed. TnT and CK-MB showed significant elevations at 12 and 24 hours versus baseline. Postoperatively, TnT was detectable in 91.3% of patients, and 17.4% suffered minor myocardial damage, as evidenced by an abnormal increase in TnT greater than 0.2 ng/mL, excluding those exhibiting myocardial infarction. ST segment changes developed in seven patients, persisting for 13.0 minutes (range, 9.5 to 15.8 minutes) and disappearing immediately after coronary artery clamp release. There were no significant correlations between cumulative coronary occlusion time and peak TnT or CK-MB levels. CONCLUSIONS: TnT was detected after surgery in most patients, and significant TnT levels indicative of myocardial injury (>0.2 ng/mL) were detected in only 17% of patients, probably as a result of brief periods of coronary artery occlusion.     

Predictive value of perioperative cardiac troponin I for adverse outcome in coronary artery bypass surgery.

OBJECTIVES: Cardiac Troponin I (cTnI) is a well-known marker for myocardial damage in patients undergoing aorto-coronary bypass grafting (CABG) peaking 6-8 h after aortic declamping. The aim of this study was to evaluate cTnI release in the course of CABG procedures early, i.e. after the cessation of cardiopulmonary bypass (CPB) in order to recognize unstable cardiac function leading to hemodynamic deterioration and resulting in an adverse outcome (AO). AO is defined as the onset of myocardial infarction and/or death peri/postoperatively. METHODS: Five-hundred and forty consecutive patients who underwent CABG were evaluated for cTnI release immediately prior to the induction of anesthesia (IND) and after termination of CPB (END). Standard CPB with ante/retrograde cold blood cardioplegia was used. Patients with any of the following criteria were excluded: (1), CABG within 7 days of myocardial infarction; (2), emergency operation for both unstable angina and for coronary occlusion at angioplasty; (3), CABG with concomitant surgical cardiac procedures; (4), preoperative renal dysfunction requiring hemodialysis; (5), redos. Troponin I was measured with the Stratus CS fluorometric enzyme immunoassay analyzer (Dade-Behring) running on site in the operation room (OR), so values of cTnI could be obtained within 15 min. RESULTS: There were six deaths (1.1%) in the entire series, Q-wave myocardial infarction occurred in 19 patients (3.5%), AO was experienced by 21 patients (3.9%). The mean preoperative cTnI level was 0.04+/-0.17 ng/l (mean+/-standard deviation) for the entire group. The END cTnI level for the AO-group was 0.91+/-0.5 ng/l; for all other patients, this was 0.37+/-0.3 ng/l (P<0.001). Changes in intraoperative cTnI levels relative to time course showed a marked increase for the AO-group (0.0038+/-0.0035 ng/l*min) as compared with non-AO patients (0.0019+/-0.0015 ng/l*min; P=0.028). The receiver operating characteristic curve indicates a cTnI level at CPB-end of higher than 0.495 ng/l with an area under the curve of 0.83 as the optimal cut-off point for predicting AO with a sensitivity and specificity of 76.2%. Stepwise logistic regression analysis revealed END cTnI level (odds ratio, 17.24; P<0.001), CPB time (odds ratio, 1.03; P=0.001), female sex (odds ratio, 3.8; P=0.011) as significant independent predictors for AO. Age of over 70 years (P=0.8), Cleveland Clinic risk score (P=0.65), diabetes (P=0.26), elevated preoperative creatinine level (P=0.77), severe left ventricular dysfunction (P=0.51), the number of grafts performed (P=0.15), and change of intraoperative cTnI level relative to time course (P=0.94) did not reach statistical significance. CONCLUSIONS: cTnI release as determined at the end of CABG procedures represents a strong predictor of an AO after surgery. Analyzing blood samples for cTnI with an automated device on site in the OR provides for immediate results, so specific diagnostic and therapeutic interventions can be performed before hemodynamics deteriorate.     

Cardiac marker responses to coronary artery bypass graft surgery with cardiopulmonary bypass and aortic cross-clamping

OBJECTIVE: To study several markers of myocardial injury in relation to aortic cross-clamping and cardiopulmonary bypass (CPB) after coronary artery bypass graft (CABG) surgery. DESIGN: Prospective observational study. SETTING: University hospital. PARTICIPANTS: Thirty adult patients who underwent elective CABG surgery with aortic cross-clamping and CPB. MEASUREMENTS AND MAIN RESULTS: Serum levels of interleukin-6 (IL-6), interleukin-8 (IL-8), troponin-T (TnT), myosin light chain I (MLCI), and MB isoenzyme of creatine kinase (CK-MB), as markers of myocardial injury, were measured after induction of anesthesia for baseline values, then again at the end of surgery and on postoperative days 1, 3, and 5. IL-6, IL-8, and CK-MB levels were significantly elevated in the early postoperative stage. TnT significantly increased from the end of surgery to postoperative day 5. MLCI increased also but later than TnT. Aortic cross-clamping time correlated positively with peak TnT (r = 0.51, p < 0.05), TnT level on postoperative day 1 (r = 0.69, p < 0.01), and MLCI level on postoperative day 5 (r = 0.45, p < 0.05). CPB time was correlated only with peak TnT (r = 0.47, p < 0.05). CONCLUSIONS: The increase in TnT level is strongly related to aortic cross-clamping.     

Strict thermoregulation attenuates myocardial injury during coronary artery bypass graft surgery as reflected by reduced levels of cardiac-specific troponin I

We assessed the cardioprotective effects of perioperative maintenance of normothermia by determining the perioperative profile of troponin I, a highly cardiac-specific protein important in risk stratification of patients with acute ischemic events. Candidates for their primary coronary artery bypass grafting (CABG) were randomized into a new thermoregulation system group, Allon( thermoregulation (AT; n = 30), and a routine thermal care (RTC; n = 30) group. Anesthetic and operative techniques were similar in both groups. Intraoperative warming was applied before and after cardiopulmonary bypass (CPB) and up to 4 h after surgery. Perioperative temperature and hemodynamic data were recorded. Blood samples for creatine kinase (CK) and its isoform, MB (CK-MB), and for cardiac-specific troponin I (cTnI) were obtained at predetermined intervals throughout the entire operation. Core and skin temperatures were higher in the AT group at all time points. The systemic vascular resistance was lower and the cardiac index higher in the AT group at all intra- and postoperative time points. Increases in CK, CK-MB, and cTnI levels indicated intraoperative ischemic insult in all patients. The respective CK levels for the AT and RTC groups were 53.3 +/- 22.7 IU/L and 47.9 +/- 17.86 IU/L at the time of anesthesia and 64.7 +/- 45.6 IU/L and 47.8 +/- 19.4 IU/L 30 min after the onset of surgery, demonstrating thereafter a steep increase before the discontinuation of CPB. CK-MB mass concentrations in both groups behaved almost identically. Pre-CPB cTnI levels at anesthesia induction were 0.3 +/- 0 ng/mL in both groups, followed by a distinctive profile observed after separation from CPB: 28.1 +/- 11.4 ng/mL, 26.05 +/- 9.20 ng/mL, and 22.3 +/- 8.9 ng/mL at discontinuation from CPB, chest closure, and 2 h after surgery, respectively, in the RTC group, versus 0.6 +/- 4.6 ng/mL, 6.6 +/- 5.5 ng/mL, and 7.9 +/- 4.76 ng/mL at these three time points, respectively, in the AT group (P < 0.01 between groups at the specified time points). Contrary to conventional thinking about the benefits of hypothermia, maintenance of normothermia throughout the non-CPB phases during CABG was demonstrated to be important in attenuating myocardial ischemic injury. Insofar as troponin I was more sensitive than other tested markers, it may provide important data on possible protection from myocardial insult and on other cardioprotective measures.     

Early extubation does not increase complication rates after coronary artery bypass graft surgery with cardiopulmonary bypass

Background: With the evolution of anesthesia and surgical procedures, fast track extubation has gained an increased interest, mainly based on the possibility of reducing health costs seemingly without compromising patient care. Aim: To compare two groups of patients submitted to a non-fast track extubation and a fast track extubation protocol after coronary artery bypass graft surgery with cardiopulmonary bypass, regarding their times of ventilation and intubation and their complication rates in the postoperative period. Methods: During the year of 1998, 323 sequential patients scheduled for isolated coronary artery bypass graft surgery with cardiopulmonary bypass were enrolled in the study. Fifty-nine patients were excluded due to preoperative use of emergent mechanical and/or inotropic hemodynamic support, low body mass index (≤18–20 kg/m²), reoperations for acute surgical complications, off-pump coronary artery bypass graft surgery, severe respiratory disease, recent myocardial infarction (≤7 days) and absence of relevant data. Previous myocardial infarction (≥7 days), prophylactic intraaortic balloon pump and use of postoperative vasoactive drugs were not exclusion criteria. We compared 76 patients sequentially submitted to anesthesia by one of the authors with a fast track extubation protocol and 188 patients sequentially submitted to anesthesia by others in the same period and using a conventional anesthetic protocol. Results: Demographic data, previous medical and cardiac history, preoperative medication and operative data were all similar between the two groups. The mean ventilation and intubation times were significantly shorter in the fast track extubation group than in the non-fast track extubation patients (30 min vs. 7 h and 50 min vs. 8 h, respectively). Forty-two percent of patients in the fast track extubation group were extubated on arrival at the intensive care unit. Morbidity and mortality were similar in both groups. Conclusions: The study shows that a very fast track extubation protocol may be safely implemented in patients submitted to coronary artery bypass graft surgery with cardiopulmonary bypass.     

七氟醚后处理对体外循环下冠状动脉旁路移植术病人心肌缺血再灌注损伤的影响

目的 探讨七氟醚后处理对体外循环(CPB)下冠状动脉旁路移植术病人心肌缺血再灌注损伤的影响.方法 择期行冠状动脉旁路移植术病人40例,性别不限,年龄55～64岁,BMI＜30 kg/m2,NYHA心功能分级Ⅰ～Ⅲ级,随机分为2组(n=20):对照组(C组)和七氟醚后处理组(S组).S组于主动脉开放即刻通过体外循环机吸入2%七氟醚,持续15 min,C组不给予任何处理.分别于麻醉诱导后、CPB转流前、停机后10 min、术毕、术后6和24 h时,记录MAP、HR、CVP、平均肺动脉压、肺动脉楔压、CO和S(v)O2,计算CI、SVI、体循环血管阻力指数和肺循环血管阻力指数.分别于主动脉阻断前、复灌6 h和术后24 h时,中心静脉取血样,测定血浆肌酸激酶(CK)、肌酸激酶同工酶(CK-MB)和乳酸脱氢酶(LDH)的活性以及肌钙蛋白I(TnI)浓度.分别于主动脉阻断前和CPB停机时,取右心耳心肌组织,观察心肌细胞超微结构,并对心肌细胞损伤程度进行评分.结果 两组间各时点血液动力学和心功能指标比较差异无统计学意义(P＞0.05).与C组比较,S组复灌6 h时血浆CK-MB和LDH活性降低,术后24 h时血浆CK活性和TnI浓度降低,CPB停机后心肌细胞损伤程度评分降低(P＜0.05).结论 七氟醚后处理可减轻CPB下冠状动脉旁路移植术病人心肌缺血再灌注损伤.     

Neutrophil CD11b upregulation during cardiopulmonary bypass is associated with postoperative renal injury

BACKGROUND: Renal injury remains a persistent complication of cardiopulmonary bypass (CPB) that, when sufficient to require dialysis, increases mortality eight-fold. The high prevalence of renal failure in sepsis and adult respiratory distress syndrome has been linked to the systemic inflammatory response associated with those disorders. We hypothesized that components of the inflammatory response to CPB may similarly contribute to post-CPB acute renal injury. METHODS: Markers of leukocyte and platelet activation peri-CPB were measured in 75 patients undergoing cardiac operation with CPB and were correlated with acute renal injury, defined as an increase (> or = 50%) in peak serum creatinine post-CPB. RESULTS: Eleven patients sustained post-CPB acute renal injury. This subset of patients demonstrated significantly greater increases in neutrophil CD11b density (p = 0.01), as well as higher total neutrophil counts (p = 0.045), compared with patients with preserved renal function. Hemodynamic instability sufficient to require postoperative hemodynamic support also predicted an increased risk of acute renal injury. However, neutrophil CD11b upregulation did not correlate with this or any other clinical variables associated with renal risk, suggesting that this marker of the neutrophil inflammatory response may independently predict renal injury. By contrast other inflammatory markers, neutrophil myeloperoxidase levels, monocyte CD11b, base line C-reactive protein, and platelet CD62P expression did not differ between the two patient groups. CONCLUSIONS: Upregulation of the neutrophil adhesion receptor CD11b and high circulating neutrophil numbers are associated with acute renal injury after CPB, suggesting a contribution by activated neutrophils to the pathophysiology of this complication.     

Increased risk associated with combined carotid endarterectomy and coronary artery bypass graft surgery: a propensity-matched comparison with isolated coronary artery bypass graft surgery

OBJECTIVE: Risk associated with combined carotid endarterectomy and coronary artery bypass graft surgery (CEA/CABG) is controversial. The present study objective was to compare morbidity and mortality outcomes in well-matched patients who underwent combined CEA/CABG surgery with patients undergoing isolated CABG surgery with and without a history of a prior CEA. DESIGN: This investigation was designed as a retrospective case-controlled study using data from the Cardiothoracic Anesthesia Patient Registry in a single tertiary institution. The patient population consisted of 1,698 isolated CABG surgery patients with carotid artery stenosis >40%, 708 patients who underwent an isolated CABG surgery but had a history of a prior CEA, and 272 combined CEA/CABG surgery patients who underwent surgery from January 4, 1993, through June 30, 2003. Propensity modeling techniques were used to calculate a propensity score for each patient. Greedy matching resulted in 272 propensity-matched pairs of combined CEA/CABG and isolated CABG patients (primary analysis) and 241 propensity-matched pairs of combined CEA/CABG surgery and isolated CABG surgery with previous CEA patients (secondary analysis). A Fisher exact, chi-square, Wilcoxon rank sum, and Student t test were applied appropriately to compare the propensity-matched pairs. RESULTS: The distribution of covariates among the propensity-matched combined CEA/CABG and isolated CABG groups were similar. Among the propensity-matched pairs in the primary analysis, overall morbidity and mortality were higher in the combined CEA/CABG group compared with the CABG group alone (overall morbidity 15% v 8.8%, p = 0.025, and mortality 5.2% v 1.1%, p = 0.007, respectively). Median intensive care unit (ICU) length of stay was longer (47 v 31 hours, p = 0.004) and hospital length of stay was longer (12 v 9 days, p < 0.001) for the combined CEA/CABG surgery compared with isolated CABG surgery, respectively. Postoperative cardiac, neurologic, serious infection, and renal morbid events were similar between the 2 groups. In the secondary analysis, the rates of mortality, overall morbidity, and neurologic morbidity were similar between the groups, whereas the median ICU and hospital length of stay were significantly longer in the combined CEA/CABG group (47.6 v 39.8 hours, p = 0.025, and 12.0 v 9.0 days, p < 0.001, respectively). CONCLUSIONS: Increased mortality and overall morbidity outcomes were found in the combined CEA/CABG group when compared with well-matched isolated CABG patients, but similar when compared with well-matched isolated CABG patients with a history of previous CEA. Patients undergoing combined CEA/CABG procedures had significantly longer ICU and hospital lengths of stay compared with patients undergoing isolated CABG procedures.     

Assessment of myocardial injury by troponin T in off-pump coronary artery grafting and conventional coronary artery graft surgery

Purpose : The present study was undertaken to assess the degree of myocardial injury, using troponin T (TnT), in off‐pump coronary artery surgery (OPCAB) and in a comparable patient group undergoing conventional coronary artery graft surgery (CABG). Methods : Twenty‐seven OPCAB and 27 CABG patients were investigated. Blood samples for TnT were taken at intubation and at 12, 24 and 72 h. Nine patients (five OPCAB, four CABG) underwent 2 h sampling for 12 h for the assessment of the TnT release profile. All patients had an electrocardiogram performed preoperatively and on the mornings of days 1 and 5 postoperatively. Results : The OPCAB group had significantly greater Canadian Heart Classification 3 patients (P = 0.003); however, other demographic data were similar between the two groups. All patients had normal TnT at initial sampling. The mean number of grafts in each group was 1.8 ± 0.6 for OPCAB and 1.9 ± 0.3 for CABG (P = NS). There were two new Q wave myocardial infarctions in the CABG group and none in the OPCAB group. These cases were excluded from biochemical analyses. Troponin T release was significantly less in the OPCAB group at 12 and 24 h (P < 0.001 and P = 0.03, respectively). Peak TnT release occurred at 6–8 h in both groups. Troponin T release was significantly lower in the OPCAB group at 2, 4, 6, 8, 10 and 12 h (P = 0.01, P = 0.03, P = 0.02, P = 0.02, P = 0.03 and P = 0.04, respectively). Postoperatively, the OPCAB group required less blood transfusion (P = 0.02). Conclusions : The OPCAB group demonstrated a significantly reduced TnT release profile compared with the CABG group.