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Background: Clinical temperature management remains challenging. Choosing the right sensor location to determine the core body temperature is a particular matter of academic and clinical debate. This study aimed to investigate the relationship of measured temperatures at different sites during surgery in deep hypothermic patients., Methods: In this prospective single-centre study, we studied 24 patients undergoing cardiothoracic surgery: 12 in normothermia, 3 in mild, and 9 in deep hypothermia. Temperature recordings of a non-invasive heat flux sensor at the forehead were compared with the arterial outlet temperature of a heart-lung machine, with the temperature on a conventional vesical bladder thermistor and, for patients undergoing deep hypothermia, with oesophageal temperature., Results: Using a linear model for sensor comparison, the arterial outlet sensor showed a difference among the other sensor positions between -0.54 and -1.12°C. The 95% confidence interval ranged between 7.06 and 8.82°C for the upper limit and -8.14 and -10.62°C for the lower limit. Because of the hysteretic shape, the curves were divided into phases and fitted into a non-linear model according to time and placement of the sensors. During cooling and warming phases, a quadratic relationship could be observed among arterial, oesophageal, vesical, and cranial temperature recordings, with coefficients of determination ranging between 0.95 and 0.98 (standard errors of the estimate 0.69-1.12°C)., Conclusion: We suggest that measured surrogate temperatures as indices of the cerebral temperature (e.g. vesical bladder temperature) should be interpreted with respect to the temporal and spatial dispersion during cooling and rewarming phases.

Background: After left ventricular assist device (LVAD) implantation, right ventricular (RV) failure is a major cause of post-operative morbidity and mortality. Recently, in patients with similar hemodynamic challenge, but less severe RV impairment, who were undergoing surgery for mitral valve repair, concomitant tricuspid valve repair improved post-operative RV re-remodeling in patients with severely dilated tricuspid annuli without tricuspid regurgitation (TR)., Methods: Pre-operative transesophageal echocardiography and clinical data were prospectively collected from 122 patients without severe TR, who were selected for LVAD implantation. Patients were assigned to one of two groups according to pre-operative tricuspid annulus diameter <43 mm or >43 mm. Groups were compared for parameters that may impact survival after LVAD implantation. Kaplan-Meier survival curves were evaluated for the impact of tricuspid annulus size and right-to-left ventricular diameter ratio (R/L ratio) on 36-month survival. Multivariate analysis was used to identify the pre-operative parameters that independently affected survival., Results: Patients with tricuspid annulus >43 mm presented with higher R/L ratio (0.73 ± 0.21 vs 0.56 ± 0.13; p < 0.00001) and higher proBNP plasma concentration (12,872 ± 13,084 vs 8,988 ± 13,018 pg/ml; p = 0.018). Both R/L ratio >0.72 and tricuspid annulus >43 mm adversely affected survival (p = 0.003 and 0.007, respectively). In the multivariate analysis only tricuspid annulus diameter >43 mm (hazard ratio 2.16, CI 1.21 to 3.84, p = 0.009) and age (hazard ratio 1.03, CI 1.00 to 1.06, p = 0.04) were independent predictors of survival after LVAD., Conclusions: Tricuspid dilation, even without severe regurgitation, adversely affects survival after LVAD implantation. Further studies are required to determine whether concomitant tricuspid valve repair may improve survival in these patients., (Copyright © 2012 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

Small infants undergoing cardiac surgery are at high risk for regional malperfusion during cardiopulmonary bypass. We report a 13-day-old neonate who underwent reconstruction of the aortic arch and closure of atrial and ventricular septum defects. Near-infrared spectroscopy probes were placed on the forehead and the calf to monitor tissue oxygenation and hemoglobin concentrations. During rewarming, after deep hypothermic circulatory arrest, the patient's calf hemoglobin concentration immediately increased but oxygenation remained low. Repositioning of the venous cannula resolved this suspected venous congestion. Simultaneous monitoring of tissue oxygenation and hemoglobin concentration allows differentiation of arterial obstruction from venous congestion., (Copyright © 2011 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Left ventricular assist device (LVAD) implantation is an accepted therapy for patients with end-stage heart failure. Post-operative right ventricular failure (RVF) still remains a major cause of morbidity and mortality in these patients. This study sought to identify echocardiography parameters to select patients with high risk of RVF after LVAD implantation., Methods: Prospectively collected pre-operative transesophageal echocardiography (TEE) and clinical data were evaluated in patients pre-selected for isolated LVAD or biventricular assist device (BiVAD) implantation. According to prevalence of RVF during the first post-operative 48 hours, patients were divided into those who developed RVF (isolated LVAD with RVF) and those who did not (isolated LVAD without RVF). Echocardiographic parameters for RV geometry, RV function, LV geometry, and the RV-to-LV end-diastolic diameter ratio (R/L ratio) were evaluated. For identification of the optimal cutoff of R/L ratio, receiver operating characteristics curves were constructed., Results: An isolated LVAD was implanted in 115 patients and BiVAD in 22 patients. RVF developed in 15 patients (13%) after isolated LVAD implantation. The R/L ratio was markedly increased in the isolated LVAD with RVF and BiVAD groups compared with the isolated LVAD without RVF group. According to the receiving operating curve, the cutoff for the R/L ratio to predict RVF was 0.72. The odds ratio that RVF will develop is 11.4 in patients with an R/L ratio >0.72 (p = 0.0001)., Conclusions: Increased R/L ratio successfully identifies patients with high risk of RVF after isolated LVAD implantation. Beyond standard measurements of RV function, the consideration of R/L ratio may be useful to improve risk stratification in patients before isolated LVAD implantation., (Copyright © 2011 International Society for Heart and Lung Transplantation. Published by Elsevier Inc. All rights reserved.)

A patient with myocardial failure after repair of an acute type A aortic dissection had acute heparin-induced thrombocytopenia develop during extracorporeal membrane oxygenation. Heparin was discontinued and the anticoagulant was switched to the direct thrombin inhibitor bivalirudin given with a bolus of 0.5 mg/kg followed by a continuous infusion of 0.5 mg/kg/h. Using this protocol, activated clotting time values ranged from 200 to 220 seconds. After prolonged extracorporeal membrane oxygenation support and recovery of left ventricular function, a right ventricular assist device was implanted during extracorporeal membrane oxygenation support with bivalirudin anticoagulation. For this procedure an additional bolus of 0.25 mg/kg bivalirudin was given, and the infusion rate increased to 1 mg/kg/h to achieve activated clotting time values of 300 to 350 seconds. Surgery was successfully performed with moderate intraoperative and postoperative blood loss and transfusion requirements.

Background: Cardiac surgical patients are at an approximate 1% to 2% risk of experiencing heparin-induced thrombocytopenia (HIT), a severe immune-mediated disease that is associated with thromboembolic events. We assessed the occurrence of this disease and its influence on clinical outcome in patients after implantation of a ventricular assist device (VAD)., Methods: This retrospective analysis assessed data from our adult patient VAD program between the years 2000 and 2005. Patients were divided into three groups: those without confirmed HIT ((non)HIT), those in whom the diagnosis of HIT was made before VAD implantation (HIT(pre)), and those who experienced HIT after VAD implantation (HIT(post)). End points assessed were procedural success, as defined by discharge from hospital or transplantation or recovery of the failing heart, as opposed to death before procedural success was achieved., Results: The data of 358 consecutive patients were analyzed. There were 330 (non)HIT patients (91.6%), 15 HIT(pre) patients (4.5%), and 13 HIT(post) patients (3.9%). Procedural success was observed in 50% of (non)HIT patients, 67% of HIT(pre) patients, and 31% of HIT(post) patients., Conclusions: Heparin-induced thrombocytopenia is a frequent complication in VAD patients and is associated with detrimental outcome when occurring after implantation. Preoperative diagnosis of HIT and the implementation of alternative anticoagulation procedures appears to be associated with better results. Early detection of HIT antibodies before or shortly after VAD implantation and immediate implementation of an alternative anticoagulation regimen may be a strategy to improve outcome.

In a patient with end stage ischemic heart failure scheduled for implantation of an axial flow pump small arteriolar flow pattern was recorded using a novel intravital microscope. Preoperative arteriolar blood flow velocity was highly pulsatile, ranging from about 7 to 16 mm per second in a 12.8 microm diameter arteriole. After implantation of the pump, this pulsatility was abrogated and arteriolar blood flow velocity changed instantaneously with changes in pump speed (eg, 2 mm/s at 5,000 rpm vs 3.5 mm/s at 8,000 rpm in an 8.9 microm diameter arteriole). This lack of flow velocity oscillations may have profound long-term effects on shear stress regulated arteriolar remodeling.

Background: Previous studies suggest that auditory evoked potentials (AEP) may be used to monitor anaesthetic depth. However, during surgery and anaesthesia, the quality of AEP recordings may be reduced by artefacts. This can affect the interpretation of the data and complicate the use of the method. We assessed differences in expert ratings of the signal quality of perioperatively recorded AEPs., Methods: Signal quality of 180 randomly selected AEP, recorded perioperatively during a European multicentre study, was rated independently by five experts as 'invalid' (0), 'poor' (1), or 'good' (2). Average (n=5) quality rating was calculated for each signal. Differences between quality ratings of the five experts were calculated for each AEP: inter-rater variability (IRV) was calculated as the difference between the worst and best classification of a signal., Results: Average signal quality of 57% of the AEPs was rated as 'invalid', 39% as 'poor', and only 4% as 'good'. IRV was 0 in only 6%, 1 in 62%, and 2 in 32% of the AEP, that is in 32% one expert said signal quality was good, whereas a different expert thought the identical signal was invalid., Conclusions: There is poor agreement between experts regarding the signal quality of perioperatively recorded AEPs and, as a consequence, results obtained by one expert may not easily be reproduced by a different expert. This limits the use of visual AEP analysis to indicate anaesthetic depth and may affect the comparability of AEP studies, where waveforms were analysed by different experts. An objective automated method for AEP analysis could solve this problem.

Background: The present pilot study was conducted to evaluate the effect of isolated short-term lung perfusion during cardiopulmonary bypass (CPB) on inflammatory response and oxygenation., Methods: A total of 24 patients undergoing elective cardiac surgery with routine CPB were prospectively assigned to three groups. Group I (n = 7), control subjects receiving neither lung perfusion nor ultrafiltration; group II (n = 9), patients undergoing lung perfusion; and group III (n = 8), patients undergoing lung perfusion plus ultrafiltration. Lung perfusion consisted of single-shot hypothermic pulmonary artery perfusion with oxygenated blood. Proteins indicative of leukocyte activation and lung injury were measured in plasma and bronchoalveolar lavage fluid (BALF). The alveolar-arterial oxygen gradient (A-aDO2) and the oxygenation index (PO2/FiO2) were also determined., Results: Oxygenation values were best preserved in group III, followed by group II. After CPB, elastase-alpha1-proteinase inhibitor complex had increased in plasma in all groups; in BALF it increased in groups I and II, but not in group III. Alpha2-macroglobulin increased significantly in BALF in group I but not in groups II and III., Conclusions: These preliminary results provide some evidence that single-shot hypothermic lung perfusion with oxygenated blood at the beginning of CPB may have a protective effect on the lungs, especially when combined with ultrafiltration.

A 42-year-old man with situs inversus was referred to our institution because of end-stage ischemic cardiomyopathy. Cardiac arrest occurred after admission, and the patient underwent cardiopulmonary resuscitation. An extracorporeal left ventricular assist device (Berlin Heart) was implanted as a bridge to transplantation. This is one of the first reports of left ventricular assist device implantation in a patient with situs inversus and ischemic cardiomyopathy.

Background: The Cox-maze procedure combined with an operation for organic heart disease is highly successful in the elimination of chronic atrial fibrillation. However, it prolongs significantly the aortic cross-clamp and operating time. In this study, a simplified left atrial maze procedure, which is a short procedure performed using a surgical radiofrequency ablation probe, is added to elective open heart procedures in patients with atrial fibrillation., Methods: Forty-eight adults with atrial fibrillation (duration, 6 months to 36 years) underwent elective open heart operations (isolated valve procedures or coronary artery bypass grafting, n = 27 patients; combined procedures, n = 21 patients) combined with intraoperative radiofrequency ablation of the left atrium. The postoperative follow-up period ranged from 1 to 11 months (mean, 4 months). Possible predictors for persistent postoperative atrial fibrillation were determined among 40 variables by univariate and multivariate analyses., Results: Intraoperative radiofrequency ablation prolonged the aortic cross-clamp time for 6 to 14 minutes (mean, 11 minutes). Freedom from atrial fibrillation was 100% intraoperatively, 25% at 1 week after operation (12 of 48 patients), 59% at 1 month postoperatively (16 of 27 patients), 64% at 3 months postoperatively (16 of 25 patients), and 92% at 6 months postoperatively (12 of 13 patients). The only predictor of postoperative atrial fibrillation was the presence of coronary artery disease (odds ratio, 7.5; 80% confidence interval, 2.24-25.13)., Conclusions: Intraoperative radiofrequency ablation of the left atrium combined with an operation for organic heart disease effectively eliminates atrial fibrillation without significant prolongation of the aortic cross-clamp and operative time. The presence of coronary artery disease decreases the success rate during the first 6 postoperative months.

In a patient with heparin-induced thrombocytopenia II and impaired renal function, anticoagulation during cardiopulmonary bypass was successfully performed by the use of unfractionated heparin and the platelet glycoprotein IIb/IIIa inhibitor tirofiban. Postoperative antithrombotic therapy with recombinant hirudin was immediately initiated. This regimen for anticoagulation for cardiopulmonary bypass in patients with heparin-induced thrombocytopenia II appears to be particularly appropriate for patients with impaired renal function or for hospitals without special experience with other alternative anticoagulation strategies.

Background: The MicroMed DeBakey left ventricular assist device (LVAD) is a chamber and valveless axial flow blood pump. We investigated parameters of the coagulation system in patients after implantation of the axial flow LVAD and patients following implantation of a pulsatile Novacor LVAD., Methods: Six consecutive patients of both groups were investigated over a period of 6 weeks after implantation. beta-Thromboglobulin, platelet factor 4, factor XIIa, thrombin/antithrombin complexes, plasmin/alpha2-antiplasmin complexes, and D-Dimer levels were measured., Results: With the exception of the plasmin/alpha2-antiplasmin levels in the Novacor group, all parameters were elevated in both groups. The levels of beta-thromboglobulin, platelet factor 4, factor XIIa, and plasmin/alpha2-antiplasmin were significantly increased in the axial flow LVAD group., Conclusions: The axial flow LVAD strongly influences the systems of contact activation and fibrinolysis. The elevation of platelet proteins appears to follow platelet damage. Although no thromboembolic events were observed in both groups, elevation of thrombin/antithrombin complexes provides convincing evidence of an increased activation of the coagulation system and the concomitant risk for the development of thromboembolism.

Study Objectives: To assess the cross-reactivity of danaparoid sodium in patients undergoing cardiovascular surgery., Design: Prospective investigation., Setting: A major European heart center and university hospital., Patients: 81 patients who underwent cardiovascular surgery during the period between January 1998 and April 1999 and were diagnosed with heparin-induced thrombocytopenia (HIT) II., Interventions: Testing was performed in patients who revealed a decrease in the platelet count >30% or a platelet count <100,000/microL during heparin therapy. Testing for HIT was performed by the use of the heparin-induced platelet-aggregation assay. Patients were evaluated as positive if an agglutination occurred in two of four of the 0.2 IU/mL heparin chambers. Patients were judged to be cross-reactive with danaparoid sodium when an agglutination occurred in two of four chambers that contained 0.2 IU/mL Orgaran., Measurements and Main Results: 281 patients (5.4% of the patients who underwent surgery during the period of the investigation) were tested for HIT II. Of these, 81 (1.5% of the total) gave a positive heparin-induced platelet-aggregation assay and 23 (28%) revealed a cross-reactivity with danaparoid sodium., Conclusion: Cross-reactivity with heparin-induced platelet antibodies occurred in 28% of the patients who tested positive for heparin-platelet antibodies. In these patients, Orgaran would not have been a safe option. In patients with HIT II undergoing cardiac surgery, cross-reactivity with danaparoid sodium must be excluded before initiation of therapy with Orgaran, otherwise, or in cases of cross-reactivity, other options such as r-hirudin are preferred.

We report a patient with traumatic aortic rupture and preoperatively unrecognized complete disruption of the bronchus for the left lower lobe. Preoperative state was complicated by inadequate oxygenation due to total atelectasis of the unventilated collapsed left lower lobe with consequent significant shunting of the unoxygenated blood. The patient had no massive pneumothorax because the intact peribronchial tissue and pleura covered the injured place, preventing important air leakage. The suspicion of possible concomitant tracheobronchial injury and early diagnostic bronchoscopy are important in patients with aortic rupture after blunt chest trauma.

Background: Recombinant hirudin is an alternative anticoagulant for cardiopulmonary bypass in patients with heparin-induced thrombocytopenia type II. Although there is no neutralizing agent for recombinant hirudin, its fast renal elimination enables quick cessation of bleeding after cardiopulmonary bypass. The aim of the study was to compare anticoagulant effects of recombinant hirudin in regards to renal function in patients with heparin-induced thrombocytopenia type II., Methods: Twenty-one patients (mean age, 65 years, and range, 35 to 82 years) underwent different complex cardiovascular procedures using recombinant hirudin as the anticoagulant for cardiopulmonary bypass. Postoperative blood loss, transfusion requirements, and hemostatic variables were compared between patients with a creatinine level lower than 1.5 mg/dL (group 1, normal renal function; n = 17 patients) and those with a creatinine level greater than 1.5 mg/dL (group 2, impaired renal function; n = 4 patients)., Results: The patients in group 1 showed no increased tendency toward postoperative bleeding. In contrast, all 4 patients in group 2 required reexploration for increased postoperative bleeding. They had higher activated partial thromboplastin times and transfusion requirements postoperatively., Conclusions: If recombinant hirudin is used as the anticoagulant for cardiopulmonary bypass in patients with heparin-induced thrombocytopenia type II and impaired renal function, the risk of postoperative bleeding is increased.

Background: The medos-HIA ventricular support system was designed as an artificial heart assist device for intractable heart failure to act as a bridge for transplantation or recovery. The aim of this study is to report on the first clinical application of the system and to evaluate the thrombotic risk with the use of the biomarker prothrombin fragment F1 + 2 and scanning electron microscopy of the blood contacting surface., Methods and Results: This device worked without any failure for 462 hours, and a sufficient output of 5.2 to 6 L was observed. No activation of the procoagulatory system occurred during pumping until the occurrence of the septicemia. Preseptic F1 + 2 levels were normal, at about 1 nmol/L. The blood contacting surfaces of the pump and the polyurethane valves were examined by means of scanning electron microscopy, and the surfaces were found to have smooth fibrin layers with no thrombogenic deposits. This fibrin layer is considered to prevent thrombotic adhesions, thereby minimizing the risk of thromboembolic complications. Post mortem examinations after pneumonia with septic shock showed no thrombus formation in this support system and around the inserted cannulas., Conclusions: The low risk for thromboembolic complications, no measurable activation of the coagulation system, and the excellent surface characteristics encourage further use of this inexpensive working device.

We have compared the Doppler against the thermodilution technique for measurement of cardiac output in six patients during aortic surgery. The correlation coefficient between the two methods was between 0.76 and 0.84 during the different periods of the operation. Using the integral nomogram instead of direct calibration, the Doppler system underestimated cardiac output in atherosclerotic patients. However, the Doppler method did register accurately significant changes in cardiac output.