Effect of an investigational vaccine for preventing Staphylococcus aureus infections after cardiothoracic surgery: a randomized trial.

IMPORTANCE: Infections due to Staphylococcus aureus are serious complications of cardiothoracic surgery. A novel vaccine candidate (V710) containing the highly conserved S. aureus iron surface determinant B is immunogenic and generally well tolerated in volunteers. OBJECTIVE: To evaluate the efficacy and safety of preoperative vaccination in preventing serious postoperative S. aureus infection in patients undergoing cardiothoracic surgery. DESIGN, SETTING, AND PARTICIPANTS: Double-blind, randomized, event-driven trial conducted between December 2007 and August 2011 among 8031 patients aged 18 years or older who were scheduled for full median sternotomy within 14 to 60 days of vaccination at 165 sites in 26 countries. INTERVENTION: Participants were randomly assigned to receive a single 0.5-mL intramuscular injection of either V710 vaccine, 60 µg (n = 4015), or placebo (n = 4016). MAIN OUTCOME MEASURES: The primary efficacy end point was prevention of S. aureus bacteremia and/or deep sternal wound infection (including mediastinitis) through postoperative day 90. Secondary end points included all S. aureus surgical site and invasive infections through postoperative day 90. Three interim analyses with futility assessments were planned. RESULTS: The independent data monitoring committee recommended termination of the study after the second interim analysis because of safety concerns and low efficacy. At the end of the study, the V710 vaccine was not significantly more efficacious than placebo in preventing either the primary end points (22/3528 V710 vaccine recipients [2.6 per 100 person-years] vs 27/3517 placebo recipients [3.2 per 100 person-years]; relative risk, 0.81; 95% CI, 0.44-1.48; P = .58) or secondary end points despite eliciting robust antibody responses. Compared with placebo, the V710 vaccine was associated with more adverse experiences during the first 14 days after vaccination (1219/3958 vaccine recipients [30.8%; 95% CI, 29.4%-32.3%] and 866/3967 placebo recipients [21.8%; 95% CI, 20.6%-23.1%], including 797 [20.1%; 95% CI, 18.9%-21.4%] and 378 [9.5%; 95% CI, 8.6%-10.5%] with injection site reactions and 66 [1.7%; 95% CI, 1.3%-2.1%] and 51 [1.3%; 95% CI, 1.0%-1.7%] with serious adverse events, respectively) and a significantly higher rate of multiorgan failure during the entire study (31 vs 17 events; 0.9 [95% CI, 0.6-1.2] vs 0.5 [95% CI, 0.3-0.8] events per 100 person-years; P = .04). Although the overall incidence of vaccine-related serious adverse events (1 in each group) and the all-cause mortality rate (201/3958 vs 177/3967; 5.7 [95% CI, 4.9-6.5] vs 5.0 [95% CI, 4.3-5.7] deaths per 100 person-years; P = .20) were not statistically different between groups, the mortality rate in patients with staphylococcal infections was significantly higher among V710 vaccine than placebo recipients (15/73 vs 4/96; 23.0 [95% CI, 12.9-37.9] vs 4.2 [95% CI, 1.2-10.8] per 100 person-years; difference, 18.8 [95% CI, 8.0-34.1] per 100 person-years). CONCLUSIONS AND RELEVANCE: Among patients undergoing cardiothoracic surgery with median sternotomy, the use of a vaccine against S. aureus compared with placebo did not reduce the rate of serious postoperative S. aureus infections and was associated with increased mortality among patients who developed S. aureus infections. These findings do not support the use of the V710 vaccine for patients undergoing surgical interventions. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00518687.

Tremendous bleeding complication after vacuum-assisted sternal closure.

Vacuum-assisted closure (VAC) of complex infected wounds has recently gained popularity among various surgical specialties. The system is based on the application of negative pressure by controlled suction to the wound surface. The effectiveness of the VAC System on microcirculation and the promotion of granulation tissue proliferation are proved. No contraindications for the use in deep sternal wounds in cardiac surgery are described. In our case report we illustrate a scenario were a patient developed severe bleeding from the ascending aorta by penetration of wire fragments in the vessel. We conclude that all free particles in the sternum have to be removed completely before negative pressure is used.

Regional citrate versus systemic heparin for anticoagulation in critically ill patients on continuous venovenous haemofiltration: a prospective randomized multicentre trial.

BACKGROUND: Continuous venovenous haemofiltration (CVVH) in the intensive care setting requires anticoagulation to prevent clotting of the extracorporeal circuit. Several protocols avoiding heparin and using regional citrate anticoagulation have been developed to diminish bleeding risks. However, data from randomized trials comparing citrate anticoagulation with systemic heparinization are very limited. METHODS: One hundred and seventy-four patients on mechanical ventilation, requiring renal replacement therapy for acute renal failure, were included in this prospective randomized multicentre trial comparing regional citrate with systemic heparin. The study was performed at nine different intensive care units at university or academic teaching hospitals. The participants were randomized to either CVVH using regional citrate anticoagulation or CVVH using systemic anticoagulation with unfractionated heparin. The primary outcome was to compare treatment efficacy represented by the patients' acid base status on Day 3 and on each consecutive day. Several parameters of safety and efficacy were analysed as secondary outcomes. RESULTS: Comparison of standard bicarbonate from Day 3 to Day 11 revealed no difference between both treatment modalities. Use of citrate resulted in less systemic anticoagulation, a lower risk of bleeding and a longer haemofilter patency. Episodes of hypercalcaemia, hypocalcaemia and the need for additional bicarbonate infusions occurred more often under citrate. The patients' high mortality was not influenced by the mode of anticoagulation. CONCLUSIONS: Citrate may be used as a regional anticoagulant and the only buffering agent in CVVH with adequate treatment efficacy and safety. However, neither citrate nor heparin anticoagulation should be regarded as a therapeutic standard, since there is no advantage of one of these substances with regard to patient mortality.

The impact of intravenous aspirin administration on platelet aspirin resistance after on-pump coronary artery bypass surgery.

Aspirin resistance continues to be a major challenge in patients after coronary artery bypass grafting (CABG). We investigated the impact of intravenous aspirin on platelet function in this clinical setting. Forty-two patients received 100 mg of oral aspirin once daily, beginning on day 1 after the operation. Between day 6 and 8 post operation one oral dose was replaced by an intravenous dose of 300 mg. Platelet function analyzer (PFA-100) closure times (CT), turbidimetric platelet aggregation (TPA) and impedance platelet aggregation (IPA) induced by arachidonic acid (AA), collagen and ADP were measured prior to and 1 h and 24 h after intravenous aspirin. Results obtained prior to the intravenous aspirin were compared with respective values from 120 healthy individuals. Despite the postoperative oral aspirin that was given once daily, ADP-induced TPA (ADPTPA) and IPA values induced by AA, ADP or collagen were significantly greater in patients than in controls, while PFA-100 CT were significantly shorter. Intravenous aspirin induced a significant reduction of platelet aggregability as measured by collagen/epinephrine (CEPI) CT, TPA and IPA induced by AA and collagen 1 h and 24 h after administration. Intravenous aspirin was not found to influence collagen/ADP (CADP) CT and IPA induced by ADP. Concomitantly, the number of patients with laboratory aspirin resistance as measured by CEPI-CT and TPA but not by IPA induced by AA or collagen dropped significantly. Agreement in the detection of aspirin responders and non-responders among platelet function tests was poor. Our findings indicate that the intravenous aspirin appears to be a promising approach for reducing laboratory aspirin resistance during the postoperative phase of CABG.

Case report: fatal hepatic failure after aortic valve replacement and sevoflurane exposure.

PURPOSE: To report a case of lethal hepatotoxicity possibly caused by sevoflurane. CLINICAL FEATURES: A 76-yr-old woman with a history of four previous minor surgical procedures developed acute liver failure after general anesthesia with sevoflurane, sufentanil and propofol for aortic valve replacement. After an uneventful procedure the patient was extubated 4.5 hr after surgery. On the second postoperative day, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) increased. On the third postoperative day liver failure occurred, ALT peaked at 10504 UxL(-1) and AST at 15516 UxL(-1), and coagulopathy with an international normalized ratio of 4.6 developed. Liver transplantation was considered but rejected as a therapeutic option. The patient died three days after the operation in multiple organ failure triggered by hepatic failure. Other possible causes for liver failure were excluded. CONCLUSIONS: Sevoflurane hepatitis as a cause for liver failure may be implicated in this patient undergoing valve surgery. Unlike other halogenated anesthetic drugs, sevoflurane is not metabolized to hepatotoxic trifluoroacetyl proteins. However, compound A may react with proteins and may be transformed into antigenic material. We suggest that all halogenated anesthetics may be implicated with acute liver injury.

Evaluating a new method for maintaining body temperature during OPCAB and robotic procedures.

BACKGROUND: We evaluated the performance of a new temperature management system (Allon Thermowrap, MTRE, Israel) in maintaining normothermia during OPCAB (Off-Pump Coronary Artery Bypass) procedures and Zeus-robotic IMA (internal mammary artery) takedowns. MATERIAL/METHODS: One hundred patients were prospectively randomized to either a conventional temperature management method (thick blanket, warm intravenous fluids, operating room temperature 25 degrees C), or the new Allon Thermowrap system (pads with temperature-controlled water circulation placed on the patient's back, legs, and arms). The mean age, body surface area, total operating time, and OR air temperature were similar in both groups. RESULTS: The Allon Thermowrap system maintained a higher bladder and nasopharyngeal temperature (p<0.05). The SVR decreased (p<0.05) and the cardiac index increased (p<0.05) in patients with a body temperature>35.80 degrees C. Without reaching a significant level, the postoperative blood loss was lower in the Allon Thermowrap group. CONCLUSIONS: The Allon Thermowrap system significantly out-performed conventional techniques in achieving and maintaining normothermia during off-pump and robotic procedures.

Advanced sternal closure to prevent dehiscence in obese patients.

Sternal dehiscence is a frequent complication after cardiac surgical procedures. The objective was to evaluate a novel method for advanced sternal closure compared with standard techniques for preventing sternal dehiscence. Our investigation comprised 100 patients with a body mass index above 32. Patients were randomly assigned to receive either advanced sternal closure with three stainless steel double wires or standard techniques with stainless steel single wires. The incidence of sternal refixation was 6 of 50 patients in the standard techniques group and 1 of 50 in the advanced sternal closure group during a follow-up period of 6 months.

Relationship between factor XIII activity, fibrinogen, haemostasis screening tests and postoperative bleeding in cardiopulmonary bypass surgery.

We investigated the relationship between factor XIII, fibrinogen, blood coagulation screening tests and postoperative bleeding in 98 patients undergoing cardiopulmonary bypass (CPB) surgery. All patients received aprotinin. Blood samples were collected preoperatively (T1),after termination of CPB (T2),12 h (T3) and 24 h (T4) after surgery to determine FXIII activity, fibrinogen, platelet count, prothrombin time (PT), activated partial thromboplastin time (APTT) and D-dimers (DD). Laboratory results were correlated with the chest tube drainage 24 h after surgery and compared between patients with 24-hour chest tube drain volumes in the lower (Group 1) with those in the upper tertile (Group 3). Median FXIII and fibrinogen levels dropped by 33.9% and 34.2%, respectively, during CPB. No association between FXIII activity and the extent of postoperative bleeding was found. However, chest tube bleeding was significantly correlated with preoperative and postoperative fibrinogen. This was confirmed by comparing Groups 1 and 3. Group 3 patients had significantly lower fibrinogen levels than Group 1 at T1 - T4, although most fibrinogen values were within or above the reference range (medians, g/l: 3.5 vs. 4.0, p = 0.043 at T1; 2.3 vs. 2.7, p = 0.015 at T2; 2.9 vs. 3.3, p = 0.008 at T3; 4.2 vs. 5.2, p = 0.002 at T4). There was also a significant relationship of platelet count, PT and APTT, as measured after CPB (T2), with postoperative chest tube drainage. In conclusion, plasma FXIII activity does not influence postoperative bleeding in patients undergoing CPB surgery. There is however an inverse association between preoperative or postoperative plasma fibrinogen levels and postoperative bleeding. These findings indicate a modulation of postoperative bleeding by fibrinogen levels.

Cardioprotective anesthesia in patients undergoing coronary surgery: fact or fiction?

The use of volatile anesthetics in patients undergoing coronary artery bypass grafting resulted in a shorter length of stay (LOS) in the intensive care unit, shorter LOS in the hospital, and a decreased need for prolonged intensive care. Volatile anesthetics exert cardioprotective effects by anesthetic preconditioning in patients at risk of myocardial ischemia. Sarcolemmal and mitochondrial ATP-dependent potassium channels are the key for anesthetic preconditioning. However, no clinical study has shown that the perioperative use of volatile anesthetics in patients undergoing coronary surgery contributes to a reduced perioperative mortality. For the first time, the study from De Hert and colleagues clearly demonstrates that inhalational anesthesia results in a reduced perioperative cardiac morbidity. In the authors opinion, cardioprotection by activation of ATP-dependent potassium channels will become part of any cardiac revascularization procedure in the future.

Blood-air interface during cardiopulmonary bypass.

The aim of this study was to compare the systemic blood activation with open and closed perfusion management during cardiopulmonary bypass. In 30 patients undergoing coronary artery bypass grafting, we prospectively studied systemic blood activation, blood loss and the need for donor blood. In 15 patients we used an open venous reservoir consisting of a hard shell venous reservoir with an integrated cardiotomy filter. In another 15 patients we used a totally closed venous reservoir consisting of a collapsible venous reservoir, no coronary suction, modified vent and cell saver. Venous blood samples were collected pre, post and 24 hours postoperatively. Sex, age and perfusion times were identical in both groups. There were no statistically significant differences in concentrations of FXIIa and C3a, amount of blood loss and need for donor blood. Interleukin-6 and Elastase levels showed trends toward a lesser inflammatory reaction in closed venous reservoir patients. Modification of perfusion management with optimized air management does not seem to be an effective strategy in reducing the inflammatory response and influencing the coagulation system in this small cohort.

The prophylactic use of the beta-blocker esmolol in combination with phosphodiesterase III inhibitor enoximone in elderly cardiac surgery patients.

We assessed the influence of the prophylactic use of a combination of the IV beta-adrenergic blocker, esmolol, and the phosphodiesterase III inhibitor, enoximone, on postbypass hemodynamic status, inflammation, and endothelial and organ function in a prospective, randomized, placebo-controlled study in 42 patients aged >65 yr undergoing aortocoronary bypass grafting. In 21 patients, esmolol (aim: heart rate <70 bpm) plus enoximone (initial bolus of 0.5 mg/kg followed by a continuous infusion of 2.5 microg x kg(-1) x min(-1)) was started after induction of anesthesia and continued until the morning of the first postoperative day; another 21 patients received saline solution as placebo. Hemodynamics, splanchnic perfusion (gastric-arterial CO(2) gap), liver function (glutathione transferase-alpha plasma levels), renal function (creatinine clearance, urine concentrations of N-acetyl-beta-D-glucosaminidase), myocardial ischemia (creatine-kinase MB and troponin T plasma levels), inflammation (elastase, interleukin-6 and -8 plasma levels), and endothelial integrity (adhesion molecules plasma levels) were assessed at baseline, before and after cardiopulmonary bypass (CPB), and in the intensive care unit until the first postoperative day. Catecholamine requirements were significantly less in the treated than in the nontreated patients. Heart rate was significantly slower, cardiac index was higher, and gastric-arterial CO(2) gap was significantly lower in the treatment group. Troponin T, beta-N-acetyl-beta-D-glucosaminidase, glutathione transferase-alpha, and soluble adhesion molecules increased significantly in the untreated control, but remained almost normal in the esmolol+enoximone patients. Inflammatory responses (elastase/interleukins) were attenuated by esmolol+enoximone. We conclude that, in comparison to an untreated control, the prophylactic use of a combination of esmolol and enoximone in elderly patients undergoing cardiac surgery with cardiopulmonary bypass resulted in overall beneficial effects on postbypass hemodynamic status, organ function, inflammatory response, and endothelial integrity.

The influence of allogeneic red blood cell transfusion compared with 100% oxygen ventilation on systemic oxygen transport and skeletal muscle oxygen tension after cardiac surgery.

In this study we investigated the effects of allogeneic red blood cell (RBC) transfusion on tissue oxygenation compared with those of 100% oxygen ventilation by using systemic oxygen transport variables and skeletal muscle oxygen tension (PtiO2). Fifty-one volume-resuscitated, mechanically ventilated patients with a nadir hemoglobin concentration in the range from 7.5 to 8.5 g/dL after elective coronary artery bypass grafting were allocated randomly to receive 1 unit (transfusion 1; n = 17) or 2 units (transfusion 2; n = 17) of allogeneic RBCs and ventilation with 40% oxygen or pure oxygen ventilation (100% oxygen; n = 17) and no allogeneic blood for 3 hours. Invasive arterial and pulmonary artery pressures and calculations of oxygen delivery (oxygen delivery index) and consumption indices (oxygen consumption index) were documented at 30-min intervals. PtiO2 was measured continuously by using implantable polarographic microprobes. Systemic oxygen transport variables and PtiO2 were similar between groups at baseline. The oxygen delivery index increased significantly with transfusion of allogeneic RBCs and 100% oxygen ventilation, whereas the oxygen consumption index remained unchanged. Oxygen 100% ventilation increased PtiO2 significantly (from 24.0 +/- 5.1 mm Hg to 34.2 +/- 6.2 mm Hg), whereas no change was found after transfusion of allogeneic RBCs. Peak PtiO2 values were 25.2 +/- 5.2 mm Hg and 26.3 +/- 6.5 mm Hg in the transfusion 1 and 2 groups, respectively. Transfusion of stored allogeneic RBCs was effective only in improving systemic oxygen delivery index, whereas 100% oxygen ventilation improved systemic oxygen transport and PtiO2. This improved oxygenation status was most likely due to an increase in convective oxygen transport with a large driving gradient for diffusion of plasma-dissolved oxygen into the tissue.

Levosimendan in patients with cardiogenic shock undergoing surgical revascularization: a case series.

BACKGROUND: Levosimendan is a new calcium sensitizer, which enhances myocardial contractility while simultaneously having vasodilatory and cardioprotective effects. These properties could be advantageous in patients with myocardial ischemia requiring inotropic support. MATERIAL/METHODS: 10 patients with acute myocardial ischemia, cardiogenic shock, and/or cardiopulmonary resuscitation undergoing emergency surgical revascularization were treated with levosimendan (bolus 6 microg.kg(-1), continuous infusion 0.2 microg.kg(-1).min(-1)) in addition to catecholamines. RESULTS: All patients treated with levosimendan and catecholamines were weaned successfully from CPB on the 1st attempt. All patients needed additional norepinephrine because of vasodilation. In 4 patients, levosimendan was stopped in the early postoperative period. 2 patients died, 8 patients survived without any multiorgan failure. Only 2 patients needed an additional intra-aortic balloon pump. In the surviving patients, postoperative ventilation lasted for 8-72 hours. CONCLUSIONS: Levosimendan may have exerted positive inotropic and cardioprotective effects in these high risk patients with acute myocardial ischemia. However, these preliminary results supporting the use of levosimendan as an inoprotective drug need to be confirmed by a large randomized prospective trial.

Kidney-specific proteins in elderly patients undergoing cardiac surgery with cardiopulmonary bypass.

UNLABELLED: In cardiac surgery, acute renal failure (ARF) is more likely in elderly patients than in younger patients. We assessed whether kidney function is different between elderly and younger cardiac surgery patients by measuring kidney-specific proteins. Forty consecutive patients aged <60 yr and 40 patients aged >70 yr without preoperative kidney dysfunction undergoing elective cardiac surgery with cardiopulmonary bypass (CPB) were included. Creatinine clearance and fractional excretion of sodium, as well as urine concentrations of N-acetyl-beta-D-glucosaminidase, alpha-1-microglobulin, glutathione transferase-pi (GST-pi), and glutathione transferase-alpha (GST-alpha) were measured after induction of anesthesia, at the end of surgery, and at the first and second postoperative days (PODs) on the intensive care unit. Patients' ages were 54 +/- 4 and 77 +/- 3 yr, respectively. Preoperative creatinine concentrations were without significant differences between the two groups. Fractional excretion of sodium was significantly higher after bypass in the elderly than in the younger patients. Urine concentrations of all kidney-specific proteins increased after CPB in the elderly (e.g., GST-pi from 16.2 +/- 3.4 to 27.7 +/- 3.9 microg/L), whereas they remained almost unchanged in the younger patients. Concentrations of all kidney-specific proteins were significantly larger in the elderly than in the younger patients even at the second POD. Although none of our patients suffered ARF requiring dialysis, increased post-CPB urine concentrations of kidney-specific proteins in the elderly suggest discrete and transient alterations in kidney integrity in comparison with a younger patient population undergoing cardiac surgery. IMPLICATIONS: Measurement of kidney-specific proteins demonstrated that patients >70 yr (mean, 77 +/- 3 yr) undergoing cardiac surgery with cardiopulmonary bypass had moderate and transient alterations in kidney integrity compared with patients aged <60 yr (mean, 54 +/- 4 yr). These abnormalities were not detected with standard measures of kidney function (e.g., creatinine concentrations).

Intracardiac left ventricular support in beating heart, multi-vessel revascularization.

BACKGROUND: Less invasive operation procedures without support of extracorporeal circulation are becoming increasingly important. A basic requirement for good long-term results in such cases is, however, the complete revascularization of the affected coronary vessels. The unsatisfactorily high conversion rate from bypass operations originally planned as off-pump to conventional operations with heart-lung machines, because of the failure to reach the target vessels on the rear wall of the heart through hemodynamic instability led to investigation of the efficiency of a microaxial pump (Impella elect) placed in the left ventricle. METHODS: In a prospective project 15 of 38 consecutive patients selected for coronary revascularization with beating heart had a micro pump transaortically implanted in the left ventricle to support the heart during the operation with a flow rate of 2.5 to 3.9 l/min. RESULTS: With 8 of 23 patients operated on without pump support, the operation had to be converted to conventional methods with a heart-lung machine. Only one patient out of the left-ventricle-supported group had to be further operated on conventionally because of a deep intramyocardial positioned left anterior descending coronary artery (LAD) (p < 0.05). The investigated laboratory parameters, especially creatine kinase (CK), CK-MB isoenzyme, and clotting showed no significant difference. There tended to be a higher blood loss recorded with the pump-supported patients. CONCLUSION: In summary, it appeared that the application of a left ventricular coaxial pump with comparable results seemed to make possible complete revascularization in nearly all patients.

Robotic surgery using Zeus MicroWrist technology: the next generation.

BACKGROUND: The use of computer-animated surgical instruments for various cardiac operations has been shown to be feasible, but to date, the available information regarding the operative and technical details of these procedures is still inadequate. METHODS: We used the Zeus (Computer Motion Inc., Goleta, Calif, USA) telemanipulation system to perform the internal mammary artery (IMA) takedown in 56 patients, in 12 of whom we used the newest model with MicroWristTM (Computer Motion Inc., Goleta, Calif, USA) technology. Port orientation was based on thoracic anatomy, the decisive landmarks being the mammillary line and the axillary line. The distance between ports was at least 9 cm, and the patient's arm was positioned with the left shoulder raised and angulated by not more than 90 degrees. RESULTS: Mean setup time was 44 +/- 18 minutes for the first five patients and 16 +/- 7 minutes for the last five patients, with an overall average of 24 +/- 12 minutes. IMA harvest time at the beginning reached a mean of 95 +/- 23 minutes and decreased to 44 +/- 18 minutes in the last five cases. Average IMA takedown time was 58 +/- 17 minutes. The IMA was patent with a good flow in all 56 patients. CONCLUSIONS: The introduction of robotic technology into clinical routine has resulted in safe procedures with a short learning curve. However, basic training in the modality is a must in order to achieve technical excellence.

Is kidney function altered by the duration of cardiopulmonary bypass?

BACKGROUND: Cardiopulmonary bypass (CPB) is considered responsible for kidney damage. By using sensitive markers of kidney damage we assessed whether the length of CPB influences kidney function. METHODS: In a prospective study, 50 consecutive cardiac operation patients with CPB times of less than 70 minutes were compared with 50 consecutive patients showing CPB times of more than 90 minutes. Aside from creatinine clearance and fractional excretion of sodium, urine concentrations of N-acetyl-beta-D-glucosaminidase, alpha1-microglobulin, glutathione transferase-pi, and glutathione transferase-alpha were measured after induction of anesthesia at the end of the operation, and on the first and second postoperative days in the intensive care unit. RESULTS: CPB times were 58 +/- 12 minutes and 116 +/- 18 minutes, respectively. Hemodynamics, volume replacement, and use of catecholamines during cardiopulmonary bypass (CPB) were without significant differences between groups. Concentrations of all kidney-specific proteins increased significantly after CPB, showing the highest significant increases in the CPB more than 90 minutes group (eg, glutathione transferase-alpha CPB > 90 minutes from 3.0 +/- 1.0 to 12.9 +/- 2.9 microg/L; glutathione transferase-alpha CPB < 70 minutes from 2.4 +/- 0.5 to 5.5 +/- 1.2 microg/L). By the second postoperative day, urine concentrations of kidney-specific proteins had returned to almost baseline in the CPB less than 70 minutes patients, but remained slightly elevated in the other group. CONCLUSIONS: Patients with CPB times more than 90 minutes showed more pronounced kidney damage than patients with CPB times less than 70 minutes as assessed by sensitive kidney-specific proteins. Whether patients with preexisting renal dysfunction undergoing prolonged CPB times would profit from renal protection strategies needs to be elucidated.

Bispectral index-guided anesthesia in patients undergoing aortocoronary bypass grafting.

In this prospective, randomized study, we compared hemodynamics, oxygenation, possible intraoperative awareness, and costs in 62 patients undergoing first-time elective coronary artery bypass grafting at 2 different levels of anesthesia. Depth of anesthesia was assessed with bispectral index (BIS). All patients were anesthetized with sufentanil/midazolam. The dosage of sufentanil/midazolam was adjusted to achieve a BIS level of 45-55 in 32 patients (Group BIS 50), whereas in 30 patients a BIS level of 35-45 was intended (Group BIS 40). Data were obtained at six different time points before, during, and after surgery. All patients were asked about possible intraoperative awareness on the third postoperative day. There were no significant differences of any hemodynamic or oxygenation variables at any time between the two groups. BIS 40 patients received significantly (P < 0.05) more sufentanil (BIS 40, 888 +/- 211 microg; BIS 50, 514 +/- 99 microg) and midazolam (BIS 40, 22.4 +/- 5.6 mg; BIS 50, 16.6 +/- 3.7 mg) than BIS 50 patients. The reduction in anesthetic drugs used saved euro;13.78/US$12.54 per patient (P < 0.05) in Group BIS 50, but one BIS electrode caused additional costs of 19.95 Euros/18.15 US dollars. Time to extubation was not significantly prolonged in Group BIS 40 (BIS 40, 14.3 +/- 4.6 h; BIS 50, 11.8 +/- 3.8 h). There was no explicit memory during anesthesia in either group. BIS-guided reduction of anesthetic medication saved costs and did not increase the risk of intraoperative awareness. However, total costs were increased by monitoring BIS, because of the BIS electrodes.

Topical application of aprotinin in cardiac surgery.

The aim of our study was to compare a systemic and a local aprotinin application in patients during coronary artery bypass graft (CABG) surgery. The advantage of a topical aprotinin application is seen in the fact that this may not lead to systemic side effects. A prospective, randomized study comprising 97 patients was conducted. A dose of 5 x 10(6) KIU aprotinin was given systemically to 49 patients and four doses of 1.25 x 10(6) KIU aprotinin were applied topically to 48 patients by spraying the substance on the target area (A. mammaria interna region and pericardium). We determined markers for the inflammatory response, coagulation system, standard haematological markers and postoperative complications. Exclusion criteria were defined as surgical bleeding, redo operations, neurological, haematological, liver and kidney disorders. Sex, age, perfusion times, mortality, renal failure and strokes were identical in both groups. Biochemical markers and clinical outcome demonstrated no significant differences between the systemic and local applications. Interleukin 6 and elastase were tendentially higher (p = 0.1) in the local group, but with a high standard deviation in each patient. Our results suggest that there is no difference between the perioperative application of 5 x 10(6) KIU systemically given aprotinin and 1.25 x 10(6) KIU locally applied aprotinin.

Platelet function test HemoSTATUS 2: tool or toy for an optimized management of hemostasis?

BACKGROUND: Bleeding after open heart surgery is a common but unintended problem, which is unequivocally related to platelet function. The target of our study was to correlate platelet activation levels and postoperative blood loss as well as the predictive power of measurements focusing on postoperative hemostasis. MATERIALS AND METHODS: The prospective trial comprised 100 patients (mean age: 64.3 years, 68% male) undergoing cardiac surgery. Platelet activation was measured by the new and modified HemoSTATUS test. Blood samples were drawn pre-, intra- and postoperatively. Standard hemostasis tests, including activated clotting time (ACT), partial thromboplastin time (PTT), hemoglobin, platelet count, antithrombin III (AT III) and fibrinogen, were measured according to the clinical routine. Blood loss and consumed blood products were documented up to the 24th hour after the operation. RESULTS: Platelet activation showed a typical change, with lowest levels after the end of extracorporeal circulation and a restitution to preoperative levels after 24 h. Mean blood loss was 461 ml. Statistical analysis showed neither a correlation to the platelet activation measurements nor to low pre-, intra- or postoperative levels. CONCLUSION: The HemoSTATUS platelet function test is not suitable for a reliable monitoring of platelet pathophysiology and patient outcome after extracorporeal circulation. Furthermore, no correlation of preoperative platelet activation and blood loss could be shown.