Safety and Efficiency of Percutaneous Dilatational Tracheostomy With Direct Bronchoscopic Guidance for Thoracic Transplant Recipients.

BACKGROUND: Percutaneous dilatational tracheostomy (PDT) is the standard airway access in critically ill patients who require prolonged mechanical ventilation. However, the literature lacks reports about the effectiveness and safety of this procedure in thoracic organ transplant recipients, who have increased risks of bleeding and infection. METHODS: We retrospectively reviewed the records of subjects who underwent thoracic organ transplantation at our institution between January 2004 and March 2011 followed by PDT (using the Ciaglia Blue Rhino technique with direct bronchoscopic guidance). RESULTS: From a total of 312 thoracic transplant recipients, we identified 93 (29.8%) subjects with PDT. Of these, 79 had undergone double lung transplant, 11 had undergone heart transplant, 2 had undergone combined heart-lung transplant, and 1 had undergone combined heart-kidney transplant. Mean age was 49.5 ± 11.2 y, and 58% of subjects were female. The mean time from intubation to PDT was 3.7 ± 3.4 d, and mean time from transplant to PDT was 12.6 ± 28.3 d. Thirty-two subjects (34.4%) underwent PDT after re-intubation. Thirty-nine subjects were receiving renal replacement therapy (41.9%), and 28 had a coagulopathy (30.1%). Moderate but not significant bleeding was observed in 3 subjects. There were no major complications during PDT procedures. Forty-five subjects (48.4%) could be weaned successfully from the ventilator and the tracheostoma could be removed. Forty-eight subjects (51.6%) died due to sepsis, multi-organ failure, or transplant failure. No procedure-related deaths were noted. There were no significant late complications. Among the 45 who survived their stay in the ICU, the functional and cosmetic outcomes of PDT were excellent. CONCLUSIONS: PDT can be safely performed on patients with acute respiratory failure after thoracic organ transplantation. Therefore, we recommend the use of this technique for prolonged airway management in these patients.

[S3-Guideline: Recommendations for intra-aortic balloon pumping in cardiac surgery]. / S3-Leitlinie "Einsatz der intraaortalen Ballongegenpulsation in der Herzchirurgie".

Although intra-aortic balloon pumping (IABP) is the most frequently used mechanical cardiac assist device in cardiothoracic surgery, there are only guidelines for substantive sections of aortic counterpulsation including prophylactic and postoperative use. In contrast, evidence-based recommendations are still lacking concerning intraoperative use, management, contraindication and other relevant issues. According to international surveys, important aspects of IABP usage show a wide variation in clinical practice. The results of a national questionnaire performed before initiation of this guideline confirmed these findings and demonstrated a clear need for the development of a consensus-based guideline. Therefore, the presented multidisciplinary S-3-guideline was developed under the direction of the German Society for Thoracic and Cardiovascular Surgery (Deutsche Gesellschaft für Thorax-, Herz- und Gefäßchirurgie, DGTHG) to make evidence-based recommendations for the usage of aortic counterpulsation after cardiothoracic surgery according to the requirements of the Association of the Scientific Medical Societies in Germany (AWMF) and the Medical Centre for Quality (Ärztliches Zentrum für Qualität - (ÄZQ)). Main topics discussed in this guideline involve IABP support in the prophylactic, preoperative, intraoperative and postoperative setting as well as the treatment of right heart failure, contraindications, anticoagulation, monitoring, weaning, and limitations of IABP therapy. The presented 15 key messages of the guideline were approved after two consensus meetings under moderation of the AWMF with participation of the German Society of Cardiology (DGK), German Society of Anaesthesiology and Intensive Care Medicine (DGAI), German Interdisciplinary Association for Intensive Care (DIVI) and the German Society for Cardiovascular Engineering (DGfK).

Prognostic significance of cardiac troponin I on admission for surgical treatment of acute pulmonary embolism: a single-centre experience over more than 10 years.

OBJECTIVES: Cardiac troponin I (cTnI) is a highly sensitive, specific marker for myocardial cell injury. We sought to determine whether cTnI on admission may help to identify patients with increased risk of open surgical embolectomy with acute pulmonary embolism (PE). METHODS: Forty-six consecutive patients with confirmed acute PE were enrolled in this prospective study. PE was confirmed by pulmonary angiography, computed tomography (CT) scan or echocardiography. Severity of PE was assessed by clinical data, and cTnI was measured within 12 h after admission. RESULTS: cTnI was elevated in 28 patients with acute PE. Preoperative right ventricular dysfunction [odds ratio (OR): 15.2; 95% confidence interval (CI): 2.02-144.8; P < 0.002], prolonged hypotension with cardiogenic shock (OR: 14.9; 95% CI: 2.2-131.1; P < 0.002) and preoperative need for resuscitation (OR: 6.0; 95% CI: 0.6-143.8; P = 0.12) were more prevalent in patients with elevated cTnI serum concentrations. cTnI-positive patients were also more likely to require inotropic support (OR: 10.0; 95% CI: 1.8-65.1; P < 0.005) and mechanical ventilation (OR: 13.5; 95% CI: 2.2-95.6; P < 0.005). Moreover, an elevated cTnI level on admission significantly correlated with both primary endpoints, in-hospital mortality (OR: 9.0; 95% CI: 1.0-215.2; P = 0.03) and major adverse clinical events (OR: 8.3; 95% CI: 1.5-62.5; P = 0.006). After multivariable risk adjustment, a positive cTnI value remained an independent predictor of in-hospital mortality (OR: 13.6; 95% CI: 3.22-145.8; P = 0.014) and major adverse clinical events (OR: 15.7; 95% CI: 4.15-133.7; P = 0.031). CONCLUSIONS: cTnI on admission may improve risk assessment of patients undergoing open surgical embolectomy due to acute PE.

Onset of heart failure determines the hepatic cell death pattern.

BACKGROUND AND RATIONALE: Acute and chronic heart failure (HF) may affect the liver, but the underlying mechanisms that lead to progressive liver damage are poorly understood. The hepatic cytokeratin-18 (CK18) epitopes M65 and M30 have been reported to distinguish between overall (necrotic) and apoptotic cell death, respectively. We aimed to evaluate the predominant hepatic cell death pattern in acute vs. chronic heart failure and examined if these assays predict the course of the disease. MAIN RESULTS: In a prospective study comprising 21 patients with acute HF (AHF) and 18 patients with chronic HF (CHF) serum levels of M65 and M30 were assessed. Compared with CHF, M65 levels were significantly increased in patients with AHF (CHF: 1,283 ± 591.6U/l vs. AHF: 20,912 ± 15,132U/l, p < 0.001). In addition, M30 levels were significantly increased in AHF (CHF: 642.2 ± 177.4U/l vs. AHF: 3,844 ± 5,293U/l, p < 0.05), but the M30/M65 ratio was significantly higher in CHF (CHF: 0.54 ± 0.15 vs. AHF: 0.20 ± 0.19, p < 0.001), indicating a greater contribution of apoptotic cell death in CHF. AHF patients with higher M30 values had a worse prognosis. CONCLUSIONS: The ratio of CK18 M30/M65 is a potential marker to discriminate AHF from CHF induced LF and M30 might be a prognostic marker for survival in AHF induced liver injury.

Refurbishment works in a hospital during normal operation.

BACKGROUND: Construction and renovation work in hospitals pose risks of fungal airborne infections for immunosuppressed patients. If possible, reconstruction work will be postponed to periods without patient treatment. However, in many situations urgent damage demands immediate refurbishment works before the transferring of patients to other wards or closure of wards is possible. Reported here are infection control related measures and implemented procedures after two incidents of water damage which occurred on a surgical ward and an intensive care unit at the University hospital of Essen. METHODS: Between January and April 2009 and between September and October 2009, respectively, concentration of air-borne particles and number of viable fungi were measured at two surgical wards and one ICU. Preventive Infection Control Measures included erection of protective walls and HEPA filtration of air from the renovation area. RESULTS: During the renovation work on the surgical ward concentrations of moulds and particles ≥5 µm were significantly higher on the left side of the renovation area than on the right side (p=0.036 and p<0.001). Concentrations of particles ≥1 µm and particles ≥5 µm on both sides of the renovation area were significantly increased when compared with the control ward on the same floor but not when compared with the control ward on the other floor. Particles of all size were significantly elevated on the ICU during the renovation work. Aspergillus fumigatus could neither be cultured of the air of cardiac surgery intensive care unit nor of the intermediate care unit (control ward). During renovation works there was no nosocomial mould infection of patients treated on the two wards. CONCLUSION: Provided that the renovation area is tightly insulated from the areas of patient care on a ward, closure does not seem to be necessary during renovation works because variation of airborne fungi is similar to that of outdoor or control air. However a multidisciplinary team should be established. This team should perform risk assessment and determine necessary protective measures before starting any construction, renovation or maintenance work in health care settings.

Comparison of thromboelastometry with procalcitonin, interleukin 6, and C-reactive protein as diagnostic tests for severe sepsis in critically ill adults.

INTRODUCTION: Established biomarkers for the diagnosis of sepsis are procalcitonin, interleukin 6, and C-reactive protein. Although sepsis evokes changes of coagulation and fibrinolysis, it is unknown whether thromboelastometry can detect these alterations. We investigated whether thromboelastometry variables are suitable as biomarkers for severe sepsis in critically ill adults. METHODS: In the observational cohort study, blood samples were obtained from patients on the day of diagnosis of severe sepsis (n = 56) and from postoperative patients (n = 52), and clotting time, clot formation time, maximum clot firmness, alpha angle, and lysis index were measured with thromboelastometry. In addition, procalcitonin, interleukin 6, and C-reactive protein levels were determined. For comparison of biomarkers, receiver operating characteristic (ROC) curves were used, and the optimal cut-offs and odds ratios were calculated. RESULTS: In comparison with postoperative controls, patients with sepsis showed an increase in lysis index (97% ± 0.3 versus 92 ± 0.5; P < 0.001; mean and SEM) and procalcitonin (2.5 ng/ml ± 0.5 versus 30.6 ± 8.7; P < 0.001). Clot-formation time, alpha angle, maximum clot firmness, as well as interleukin 6 and C-reactive protein concentrations were not different between groups; clotting time was slightly prolonged. ROC analysis demonstrated an area under the curve (AUC) of 0.901 (CI 0.838-0.964) for the lysis index, and 0.756 (CI 0.666-0.846) for procalcitonin. The calculated cut-off for the lysis index was > 96.5%, resulting in a sensitivity of 84.2%, and a specificity of 94.2%, with an odds ratio of 85.3 (CI 21.7-334.5). CONCLUSIONS: The thromboelastometry lysis index proved to be a more reliable biomarker of severe sepsis in critically ill adults than were procalcitonin, interleukin 6, and C-reactive protein. The results also demonstrate that early involvement of the hemostatic system is a common event in severe sepsis.

Perioperative thrombocytopenia in cardiac surgical patients - incidence of heparin-induced thrombocytopenia, morbidities and mortality.

OBJECTIVES: Heparin-induced thrombocytopenia (HIT) is a life-threatening complication of heparin therapy. At our institution, postoperative cardiac surgical patients are screened for HIT antibodies, when platelet counts persist to be less than 50% of the baseline level or less than 50000 nl(-1). In the present study, we compared the outcomes in HIT-antibody-positive and HIT-antibody-negative patients. METHODS: Patients who underwent a cardiac surgical procedure between 1999 and 2007 and in whom a clinical suspicion of HIT prompted a test for heparin-dependent platelet-activating antibodies, that is, the heparin-induced platelet activation (HIPA) test, were retrieved from the database. Patients were divided in group 1 (antibodies present) and group 2 (no antibodies present). RESULTS: In 153 of more than 10000 patients (1.5%), a HIPA test was performed, Of those, 21 patients tested positive (group 1) and 132 tested negative (group 2). Central venous and pulmonary thrombo-embolism was more frequent in group 1 (10% vs 2%, p=0.04). Intestinal, microvascular thrombo-embolism was more frequent in group 2 (15% as opposed to 0%, p=0.03). By multivariate analysis, only patient age (p=0.04, confidence interval (CI): 1.04 (1.00-1.08)), female sex (p=0.03 CI 3.45 (1.51-7.86)) and perioperative sepsis (p<0.001 CI 6.88 (2.96-16.02)) were associated with mortality. CONCLUSION: Patients in whom a low platelet count prompted testing for HIT antibodies, had a high mortality (59%), independent of whether heparin-dependent antibodies were present, indicating that a persistently lowered platelet count is a bad prognostic sign after cardiac surgery. Interestingly, the HIPA-positive patients had more central venous and pulmonary embolisms. Patient age, female sex and perioperative sepsis were risk factors for perioperative mortality.

Thrombophilia in cardiac surgery--patients with protein S deficiency.

BACKGROUND: Thrombophilic diathesis may cause severe problems in cardiac surgical patients. Among these, protein S deficiency is a coagulation disorder associated with recurrent thromboembolic events. We analyzed our experience with 7 patients with protein S deficiency who underwent cardiac surgery. METHODS: We retrospectively reviewed the clinical data, operative and postoperative courses, and the long-term results of 7 patients who were diagnosed to have protein S deficiency. Six of them were operated on using cardiopulmonary bypass, one was operated on with an off-pump procedure. RESULTS: Procedures performed were emergent pulmonary embolectomy (patient 1), aortic valve replacement and coronary artery bypass grafting (CABG, patient 2), re-CABG (patients 3 and 7), and CABG (patients 4, 5, and 6). In patients 1, 2, 3, and 7, the diagnosis was made perioperatively. Patients 4, 5, and 6 were treated with a modified regimen of warfarin or protamine. All of the latter 3 patients had an uneventful perioperative course without thromboembolic complication. At follow-up, all but 1 of the 7 patients were on continuous warfarin, and were well and without any further thromboembolic events. CONCLUSIONS: In patients with a past medical history of thromboembolic events or with a perioperative thromboembolic complication, elaborate laboratory investigation should lead to a definite diagnosis. For instance, patients with protein S deficiency undergoing cardiac surgery belong to a high-risk subgroup. Although rare, this and other coagulation disorders can be a critical issue in cardiac surgery. In such patients, we suggest perioperative warfarin therapy with a target international normalized ratio of 2.0 and incomplete protamine antagonism to minimize the risk of a perioperative thromboembolic event.

Administration of C1-esterase inhibitor during emergency coronary artery bypass surgery in acute ST-elevation myocardial infarction.

OBJECTIVE: Myocardial inflammatory response including complement activation was demonstrated as an important mechanism of ischemia-reperfusion injury and complement inhibition by C1-esterase inhibitor (C1-INH) has recently shown to have cardioprotective effects in experimental and clinical settings. METHODS: The effects of C1-INH on complement activation, myocardial cell injury, and clinical outcome were studied in patients undergoing emergency CABG due to acute ST-elevation myocardial infarction (STEMI) with (group 1, CABG+STEMI+C1-INH, n=28) and without (group 2, CABG+STEMI, n=29) bolus administration of C1-INH (40 IU kg(-1)) during reperfusion and 6 h postoperatively (20 IU kg(-1)) besides the same study protocol. C1-INH activity, C3c and C4 complement activation fragments, and cardiac troponin I (cTnI) were measured preoperatively and up to 48 h postoperatively and compared to another elective set of CABG patients without STEMI as controls (group 3, CABG-STEMI, n=10). Clinical data, adverse events, and patient outcome were recorded prospectively. RESULTS: Patient characteristics were not different between groups 1 and 2. No drug-related adverse events were observed. Constant plasma levels of C1-INH were found in group 1, but not in groups 2 and 3. Plasma levels of C3c and C4 complement fragments were reduced in all three groups after surgery throughout the observation time, but tended to be lower in groups 1 and 2 compared with group 3. Preoperative cTnI levels were elevated but not different between the groups 1 and 2. The area under curve (AUC), as well as the postoperative cTnI serum levels, was significantly lower (P<0.05) in group 1 with a treatment delay < or = 6 h between reperfusion and symptom onset compared to group 2 at 36 h (47.9+/-11.1 ng/ml vs 97.7+/-17.2 ng/ml; mean+/-SEM), and 48 h (33.5+/-5.8 ng/ml vs 86.5+/-19.2 ng/ml) after surgery, but remained unchanged between groups among patients with a treatment delay of more than 6-24 h. In-hospital adverse events and postoperative complications, ICU and hospital stay, as well as in-hospital mortality (14.3% vs 13.8%; P=NS) were not different between groups 1 and 2. CONCLUSIONS: C1-INH administration in emergency CABG with acute STEMI is safe and effective to inhibit complement activation and may reduce myocardial ischemia-reperfusion injury as measured by cTnI.

Prognostic value of preoperative cardiac troponin I in patients undergoing emergency coronary artery bypass surgery with non-ST-elevation or ST-elevation acute coronary syndromes.

BACKGROUND: Cardiac troponin I (cTnI) is a highly sensitive and specific biomarker which has been shown to predict patient outcome pre- and postoperatively following elective coronary artery bypass surgery (CABG). Whether preoperatively elevated cTnI levels similarly predict the outcome in patients undergoing emergency CABG with acute myocardial infarction (AMI) is currently unknown. METHODS AND RESULTS: A possible correlation between preoperative cTnI and in-hospital mortality and major adverse cardiac events (MACE) was investigated in 57 patients with ST-elevation AMI (STEMI) in group 1 and 197 with Non-ST-elevation AMI (NSTEMI) in group 2, who were operated within 24 hours after onset of symptoms. Primary study end point was all-cause in-hospital mortality. Secondary end points were low cardiac output syndrome (LCOS) and hospital course. CTnI levels on admission were higher in group 1 compared with group 2 (7.1+/-1.8 versus 1.4+/-1.8 ng/mL; P<0.001). Overall in-hospital mortality was higher in group 1 compared with group 2 (14.3 versus 4.1%; odds ratio [OR], 3.9, 95% confidence interval [CI], 1.3 to 12.3; P<0.01). LCOS occurred in 16/57 (28.1%), and 18/197 (9.1%) patients, respectively (OR, 3.9, 95% CI, 1.7 to 8.8; P<0.001). Postoperative ventilation time, intensive care, and hospital stay were significantly longer in group 1 versus group 2. Multivariate logistic regression analyses revealed preoperative cTnI as the strongest independent predictor for in-hospital mortality (P<0.001) and MACE (P<0.001) in all AMI patients, regardless whether ST-elevation was included as an additional risk factor or not. CONCLUSIONS: Preoperative cTnI measurement before emergency CABG appears as a powerful and independent determinant of in-hospital mortality and MACE in acute STEMI and NSTEMI.

Emergency re-revascularization with percutaneous coronary intervention, reoperation, or conservative treatment in patients with acute perioperative graft failure following coronary artery bypass surgery.

OBJECTIVE: Perioperative graft failure following coronary artery bypass grafting (CABG) results in acute myocardial ischemia/infarction (PMI), which may necessitate an acute secondary revascularization procedure to salvage myocardium, in order to preserve ventricular function and improve patient outcome. Whether acute percutaneous coronary (re)intervention (PCI), emergency reoperation, or conservative intensive care treatment should be applied, is currently unknown. METHODS: In order to identify the source of PMI and to pursue the appropriate re-revascularization strategy, coronary repeat angiography was emergently performed in 118 among 5427 consecutive isolated CABG patients with evidence of PMI. As a result, patients immediately underwent acute PCI (group 1), emergency reoperation (group 2), or were treated conservatively (group 3). Primary study endpoint was postoperative myocardial infarct size, as measured by peak cardiac troponin I (cTnI) serum levels. Secondary endpoints were perioperative left ventricular ejection fraction (LVEF%), assessed by transesophageal echocardiography, major adverse cardiac events, and short- and midterm mortality. RESULTS: Repeat coronary angiography revealed early perioperative bypass graft failure in 67 among 118 patients and 84 among 214 bypass grafts after CABG. The number and type of failing bypass grafts were comparable between groups 1 and 2, but significantly different to that of group 3 (P<0.007). Acute PCI was applied in 25 patients, redo-CABG in 15 patients, and conservative treatment in 27 patients. Procedural peak cTnI serum levels were significantly different between groups 1 and 2 (81+/-18 ng/ml vs 178+/-62 ng/ml; P<0.001). Global LVEF was reduced during the acute ischemic event when compared with preoperative values (P<0.01). Thereafter, LVEF improved during follow-up within each group (P<0.001), but did not differ between the three groups. In-hospital and 1-year mortality were 12.0% and 20.0% in group 1, 20.0% and 27% in group 2, and 14.8% and 18.5% in group 3, respectively (P=NS). CONCLUSIONS: Re-revascularization with emergency PCI may limit the extent of myocardial cellular damage compared with the surgical-based treatment strategy in patients with acute perioperative myocardial ischemia due to early graft failure following CABG.

Diagnostic discrimination between graft-related and non-graft-related perioperative myocardial infarction with cardiac troponin I after coronary artery bypass surgery.

AIMS: The rise of markers for myocardial injury indicates early graft-related or non-graft-related perioperative myocardial infarction (PMI) after coronary artery bypass grafting (CABG). A diagnostic discrimination between these two situations may enable adequate therapeutic measures, limiting myocardial damage, and improving outcome. METHODS AND RESULTS: In a prospective study, 94 among 3308 consecutive CABG patients underwent acute reangiography because of evidence of PMI. Of these 94 patients, 56 had graft-related PMI (group 1), 38 patients had non-graft-related PMI (group 2), and 95 patients without evidence of PMI and angiographically patent grafts served as control (group 3). Cardiac troponin I (cTnI), creatine kinase (CK), and its MB fraction were determined. CTnI, but not CK/CK-MB levels were significantly higher in group 1 than in groups 2 and 3 at 12 and 24 h after aortic unclamping (P<0.0001). Receiver operating characteristic and multivariable logistic regression analyses indicated cTnI as the best discriminator between PMI 'in general' and 'inherent' release of cTnI after CABG with a cut-off value of 10.5 ng/mL and between graft-related and non-graft-related PMI with a cut-off value of 35.5 ng/mL. CONCLUSION: Perioperative cTnI elevation after CABG separates among patients with graft-related, non-graft-related, and without PMI, however, not earlier than 12 h after surgery.

Antiphospholipid syndrome in cardiac surgery-an underestimated coagulation disorder?

OBJECTIVE: Antiphospholipid syndrome (APS) is a rare coagulation disorder associated with recurrent arterial and venous thrombotic events. We analysed our experience with five APS patients who underwent cardiac surgery. In three of them the diagnosis of APS had been established before surgery, two patients were diagnosed after surgery. METHODS: From March 1999 to March 2004 five patients with APS underwent cardiac surgery using cardiopulmonary bypass (CPB). We retrospectively reviewed their clinical data, operative and postoperative courses, and the long-term results. RESULTS: Procedures performed were heart and lung transplantation (patient 1), endoventriculoplasty and CABG (patient 2), biventricular resection of endoventricular fibrosis and thrombus (patient 3), mitral valve repair repair and coronary artery bypass grafting (CABG, patient 4), and mitral valve replacement with closure of a patent foramen ovale (patient 5). There were three perioperative deaths (patients 1, 2 and 3), two of three patients in whom the diagnosis was known before surgery, survived (patients 4 and 5). In these patients, only half the dose of protamin (patient 4) and no protamin at all (patient 5) was applied to reduce the probability of postoperative thromboembolic complications. At 1 year follow up, only patient 4 had survived, patient 5 had died of the complications of intestinal thromboembolism. CONCLUSIONS: Patients with APS undergoing cardiac surgery belong to a high risk subgroup. Thus, though rare, APS can be a critical issue in cardiac surgery. Some of the cardiac patients with unexplained perioperative thromboembolic complications, such as graft occlusion, may turn out to have an undiagnosed APS.

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.

Early detection of acute renal failure by serum cystatin C.

BACKGROUND: Acute renal failure (ARF) is associated with high mortality. Presently, no specific therapy for ARF exists. Therefore, early detection of ARF is critical to prevent its progression. However, serum creatinine, the standard marker to detect ARF, demonstrates major limitations. We prospectively evaluated whether serum cystatin C detected ARF earlier than serum creatinine. METHODS: In 85 patients at high risk to develop ARF, serum creatinine and cystatin C were determined daily. ARF was defined according to the Risk of renal dysfunction, Injury to the kidney, Failure of kidney function, Loss of kidney function, and ESRD (RIFLE) classification when creatinine increased by >/=50% (R-criteria), by >/=100% (I-criteria), or by >/=200% (F-criteria). In analogy, ARF was detected when cystatin C increased by >/=50%, by >/=100%, or by >/=200%. RESULTS: Forty-four patients developed ARF and 41 served as controls. In ARF by R-, I-, and F-criteria, the increase of cystatin C significantly preceded that of creatinine. Specifically, serum cystatin C increased already by >/=50% 1.5 +/- 0.6 days earlier compared to creatinine. Serum cystatin C demonstrated a high diagnostic value to detect ARF as indicated by area under the curve of the ROC analysis of 0.82 and 0.97 on the two days before the R-criteria was fulfilled by creatinine. Cystatin C detected ARF according to the R-criteria with a sensitivity of 55% and 82% on these days, respectively. Cystatin C also performed excellently, detecting ARF defined by the I- and F-criteria two days prior to creatinine, and moderately well predicting renal replacement therapy in the further course of ARF. Additionally, low T(3)- or T(3)/T(4) syndrome, glucocorticoid deficiency and excess did not affect cystatin C levels, adding to its usefulness in critically ill patients with ARF. CONCLUSION: Serum cystatin C is a useful detection marker of ARF, and may detect ARF one to two days earlier than creatinine.

Role of troponin I, myoglobin, and creatine kinase for the detection of early graft failure following coronary artery bypass grafting.

OBJECTIVE: The detection of early graft failure following coronary artery bypass grafting (CABG) enables immediate reintervention and may significantly limit myocardial damage, thus potentially improving outcome. To date, non-invasive indicators of early graft failure following coronary surgery are still of uncertain diagnostic value. METHODS: In a prospective study, patients following isolated CABG with a postoperative serum cardiac troponin I (cTnI) above 20 ng/ml or significant ECG-changes underwent acute repeat angiography. cTnI, myoglobin (Myo), and creatine kinase (CK) were measured preoperatively and at 1, 6, 12, and 24 h after aortic unclamping. Peak values of cTnI, Myo, CK and isoenzyme CK-MB were determined postoperatively. Receiver operating curves (ROC) for cTnI, Myo and CK/CK-MB were constructed at 6, 12, and 24 h after aortic unclamping to differentiate between patients with and without early graft failure. Based on these curves, the area under curve+/-standard deviation (AUC+/-SD), the sensitivity and specificity were calculated. RESULTS: Out of 2078 consecutive patients having undergone isolated CABG from January 2001 to April 2003, 55 fulfilled the inclusion criteria and underwent acute repeat angiography. Early graft failure was found in 35 patients (group 1), whereas 20 patients did not show graft failure (group 2). CTnI and Myo, but not CK and CK-MB levels were significantly increased in group 1 compared to group 2 at 12 and 24 h after aortic unclamping. ROC analysis of cTnI, Myo and CK/CK-MB indicated cTnI as the best discriminator between the groups with 21.5 ng/ml at 12 h (AUC, 0.82+/-0.06; sensitivity, 82%; specificity, 66%) and 33.4 ng/ml at 24 h (AUC, 0.95+/-0.03; sensitivity, 98%; specificity, 82%) and Myo with 887 microg/ml at 12 h (AUC, 0.72+/-0.07; sensitivity, 73%; specificity, 57%) after aortic unclamping. In contrast, CK/CK-MB as well as the appearance of ECG-changes could not separate between the groups. CONCLUSIONS: cTnI, but not Myo and CK served as a reliable marker for the identification of patients with early graft failure following CABG.

Prognostic value of tubular proteinuria and enzymuria in nonoliguric acute tubular necrosis.

BACKGROUND: Acute tubular necrosis (ATN) has high mortality, especially in patients who require renal replacement therapy (RRT). We prospectively studied the diagnostic accuracy of the urinary excretion of low-molecular-weight proteins and enzymes as predictors of a need for RRT in ATN. METHODS: In 73 consecutive patients with initially nonoliguric ATN, we measured urinary excretion of alpha(1)- and beta(2)-microglobulin, cystatin C, retinol-binding protein, alpha-glutathione S-transferase, gamma-glutamyltransferase, lactate dehydrogenase, and N-acetyl-beta-D-glucosaminidase early in the course of ATN. RESULTS: Twenty-six patients (36%) required RRT a median of 4 (interquartile range, 2-6) days after detection of proteinuria and enzymuria. Patients who required RRT had higher urinary cystatin C and alpha(1)-microglobulin [median (interquartile range), 1.7 (1.2-4.1) and 34.5 (26.6-45.1) g/mol of creatinine] than patients who did not require RRT [0.1 (0.02-0.5) and 8.0 (5.0-17.5) g/mol of creatinine]. Urinary excretion of cystatin C and alpha(1)-microglobulin had the highest diagnostic accuracies in identifying patients requiring RRT as indicated by the largest areas under the ROC curves: 0.92 (95% confidence interval, 0.86-0.96) and 0.86 (0.78-0.92), respectively. Sensitivity and specificity were 92% (95% confidence interval, 83-96%) and 83% (73-90%), respectively, for urinary cystatin C >1 g/mol of creatinine, and 88% (78-93%) and 81% (70-88%) for urinary alpha(1)-microglobulin >20 g/mol of creatinine. CONCLUSION: In nonoliguric ATN, increased urinary excretion of cystatin C and alpha(1)-microglobulin may predict an unfavorable outcome, as reflected by the requirement for RRT.

Perfusing and ventilating the patient's lungs during bypass ameliorates the increase in extravascular thermal volume after coronary bypass grafting.

BACKGROUND: To test the hypothesis that bilateral extracorporeal circulation (ECC) (Drew technique) ameliorates the increase in extravascular thermal volume (ETV) observed after conventional cardiopulmonary bypass (CPB) in patients undergoing coronary artery bypass grafting. METHODS: Thirty-four consecutive patients underwent either bilateral ECC (n = 24, additional cannulation of pulmonary artery and left atrium and lungs perfused and ventilated during bypass) or conventional CPB (n = 10, right atrial and aortic cannulation, lungs statically inflated to 4 mbar (0.41 cm H(2)O) with oxygen, 500 mL/min). Determinations of ETV (thermodye dilution technique) and intraoperative fluid balance were made before surgery, at the end of surgery, and 4 hours thereafter. In addition, interleukin (IL)-8, thromboxane B2 (TxB(2)), and endothelin (ET)-1 concentrations were measured in the right atrium and pulmonary vein at specified time points. RESULTS: Comparisons of ETV made at the start of surgery, after aortic declamping, and after termination of ECC, respectively, revealed an increase from 4.8 +/- 0.2 mL/kg (mean +/- SEM) to 6.7 +/- 0.4 mL/kg, and 6.3 +/- 0.3 mL/kg with conventional CPB but ETV remained unchanged at 5.2 +/- 0.3 mL/kg, 5.1 +/- 0.2 mL/kg, and 4.9 +/- 0.3 mL/kg with bilateral ECC. Priming volume (1,580 +/- 10 mL versus 2,213 +/- 77 mL, p < 0.001) and intraoperative fluid balance (+1,955 +/- 233 mL versus +2,654 +/- 210 mL, p < 0.05) were less with conventional CPB. Concentrations of IL-8, TxB(2), and ET-1 were not different between groups. CONCLUSIONS: Despite a significantly greater prime volume and a more positive intraoperative fluid balance, ETV did not change with bilateral ECC but increased with conventional CPB. Thus, using the patient's lungs as an oxygenator during bypass mitigates the increase in extravascular pulmonary fluid.