Mild hypothermia during cardiopulmonary bypass assisted CABG is associated with improved short- and long-term survival, a 18-year cohort study.

Data substantiating the optimal patient body temperature during cooling procedures in cardiac operations are currently unavailable. To explore the optimal temperature strategy, we examined the association between temperature management and survival among patients during cardiopulmonary bypass assisted coronary artery bypass grafting (CABG) procedures on 30-days and 5-year postoperative survival. Adult patients (n = 5,672, 23.6% female and mean (SD) age of 66 (10) years) operated between 1997 and 2015 were included, with continuous measured intraoperative nasopharyngeal temperatures. The association between mortality and patient characteristics, laboratory parameters, the lowest intraoperative plateau temperature and intraoperative cooling/rewarming rates were examined by multivariate Cox regression analysis. Machine learning-based cluster analysis was used to identify patient subgroups based on pre-cooling parameters and explore whether specific subgroups benefitted from a particular temperature management. Mild hypothermia (32-35°C) was independently associated with improved 30-days and 5-year survival compared to patients in other temperature categories regardless of operation year. 30 days and 5-year survival were 98% and 88% in the mild hypothermia group, whereas it amounted 93% and 80% in the severe hypothermia (<30°C). Normothermia (35-37°C) showed the lowest survival after 30 days and 5 years amounting 93% and 72%, respectively. Cluster analysis identified 8 distinct patient subgroups principally defined by gender, age, kidney function and weight. The full cohort and all patient subgroups displayed the highest survival at a temperature of 32°C. Given these associations, further prospective randomized controlled trials are needed to ascertain optimal patient temperatures during CPB.

Apoptosis during CABG surgery with the use of cardiopulmonary bypass is prominent in ventricular but not in atrial myocardium.

Objectives. We aimed to compare the rate of apoptosis after cardiopulmonary bypass (CPB) and cardioplegic arrest during coronary artery bypass grafting (CABG) surgery between atrial and ventricular tissue.Methods. During CABG surgery with CPB and cardioplegic arrest, sequential biopsies were taken from the right atrial appendage and left ventricular anterior wall before CPB and after aortic cross clamp release. Change in number of apoptotic cells and biochemical markers of myocardial ischaemia and renal dysfunction were assessed.Results. CPB was associated with a transient small, but significant increase in CK (1091+/-374%), CK-MB (128+/-38%), troponin-T (102+/-13%) and NT-proBNP (1308+/-372%) levels (all: p<0.05). A higher number of apoptotic cells as assessed by caspase-3 staining was found in the ventricular biopsies taken after aortic cross clamp release compared with the biopsies taken before CPB (5.3+/-0.6 vs. 14.0+/-1.5 cells/microscopic field, p<0.01). The number of apoptotic cells in the atrial appendage was not altered during CPB. Correlation between the duration of aortic cross clamp time and the change in caspase-3 positive cells in the left ventricular wall was of borderline significance (r of 0.58, p=0.08). Similar results were obtained from TUNEL staining for apoptosis.Conclusion. CABG surgery with CPB and cardioplegic arrest is associated with an elevated rate of apoptosis in ventricular but not in atrial myocardial tissue. Ventricular tissue may be more sensitive to detect changes than atrial tissue, and may be more useful to investigate the protective effects of therapeutic intervention. (Neth Heart J 2010;18:236-42.).

Pressure drop, shear stress, and activation of leukocytes during cardiopulmonary bypass: a comparison between hollow fiber and flat sheet membrane oxygenators.

The membrane oxygenator is known to be superior to the bubble oxygenator, but little information is available about the difference between the hollow fiber and flat sheet membrane oxygenators with regard to pressure drop, shear stress, and leukocyte activation. In this study, we compared these 2 types of membrane oxygenators in patients undergoing cardiopulmonary bypass (CPB) surgery with special focus on leukocyte activation and pressure drop across the oxygenators. Plasma concentration of elastase, a marker indicating leukocyte activation, increased to 593+/-68% in the flat sheet oxygenator group versus 197+/-42% in the hollow fiber oxygenator group (p<0.01) at the end of CPB compared to their respective baseline concentrations before CPB. Pressure drop across the oxygenator was significantly higher in the flat sheet group than in the hollow fiber group throughout the entire period of CPB (p<0.01). High pressure drop across the oxygenator as well as the calculated shear stress was positively correlated with the release of elastase at the end of CPB (r = 0.760, p<0.01, r = 0.692, p<0.01). However, this positive correlation existed in the flat sheet oxygenator but not in the hollow fiber oxygenator. Clinically, both membrane oxygenators have satisfactory performance in O2 and CO2 transfer. These results suggest that a higher pressure drop across the flat sheet oxygenator is associated with more pronounced activation of leukocytes in patients undergoing cardiopulmonary bypass.

[Partial left ventriculectomy (Batista procedure) for the treatment of terminal heart failure after rejection for heart transplantation]. / Partiële linker ventriculectomie (Batista-operatie) ter behandeling van eindstadium hartfalen na afwijzing voor harttransplantatie.

A woman aged 64 was severely handicapped by dyspnoea due to 'terminal heart failure' resulting from idiopathic dilated cardiomyopathy. The mitral valve was seriously insufficient; the coronary vessels were normal. The patient was not eligible for heart transplantation. Partial left ventriculectomy by Batista's method was performed and the mitral valve replaced by an artificial one. The left ventricular ejection fraction increased from 0.12 before the operation to 0.35 postoperatively and to 0.43 two years later. Patient was then capable of normal exercise (New York Heart Association (NYHA): class I-II). In the Netherlands partial left ventriculectomy is the last surgical option for patients rejected for heart transplantation.

The use of neuromuscular blocking agents in noncardiac surgery after dynamic cardiomyoplasty.

Dynamic cardiomyoplasty is a surgical treatment to improve cardiac performance in patients with end-stage heart failure by wrapping the latissimus dorsi muscle around the heart. The use of skeletal muscle raises concerns about the safety of neuromuscular blocking agents used during general anaesthesia in noncardiac surgery in patients after cardiomyoplasty. We describe the administration of rocuronium to a patient undergoing carotid endarterectomy 18 months after cardiomyoplasty. No clinically relevant effects on haemodynamics were observed. We conclude that the use of nondepolarising neuromuscular blocking agents for noncardiac surgery in patients after cardiomyoplasty does not compromise cardiac performance in a clinically relevant way, although the time between the cardiomyoplasty procedure and the use of nondepolarising neuromuscular blocking agents remains a concern.

Blood compatibility of two different types of membrane oxygenator during cardiopulmonary bypass in infants.

The contact of blood with the artificial extracorporeal circuit causes a systemic inflammatory response due to blood activation. In this study, we compared two different paediatric membrane oxygenators used for extracorporeal circulation: a hollow fibre membrane oxygenator (Dideco Masterflo D-701, n = 10), and a flat sheet silicone membrane oxygenator (Avecor Kolobow 800-2A, n = 10). Blood compatibility was indicated by measuring complement activation as well as leukocyte and platelet activation. In patients perfused with a flat sheet membrane oxygenator, concentrations of complement split products C3a were significantly increased 30 minutes after the start of bypass (p < 0.01), whereas only a mild increase of C3a was found in patients perfused with a hollow fibre membrane oxygenator. Leukocyte and platelet counts dropped uniformly in both groups after the start of bypass mainly due to hemodilution. Activation of leukocytes and platelets identified by both plasma beta-glucuronidase and beta-thromboglobulin was similar in both groups. Infants perfused with a flat sheet membrane oxygenator received significantly more donor blood than those perfused with a hollow fibre oxygenator (p < 0.05). These results indicate that when used during paediatric cardiopulmonary bypass, a flat sheet membrane oxygenator has a higher complement activity than a hollow fibre membrane oxygenator, which is probably due to the relatively larger blood-surface contacting area of the oxygenator.

Hemodynamic effects of dopexamine in patients following coronary artery bypass surgery.

Dopexamine is a new dopamine analogue, with combined agonist properties on dopamine receptors and the beta 2-adrenoceptor. The aim of this study was to evaluate the short-term hemodynamic effects of dopexamine at different dosage rates in postoperative coronary artery bypass (CABG) patients, especially with respect to the right ventricle, using a right ventricular ejection fraction pulmonary artery catheter. With a dose of 2 micrograms/kg/min of dopexamine, significant increases in heart rate (25%), cardiac index (33%), and right ventricular ejection fraction (20%) were observed. Pulmonary vascular resistance decreased with a dose over 1 microgram/kg/min (15%). Mean arterial blood pressure and pulmonary artery pressures were not affected. At 4 micrograms/kg/min, cardiac index was further increased. In conclusion, dopexamine could be beneficial to patients with a compromised right ventricle by lowering afterload and improving ventricular performance after CABG.

A combination of buprenorphine and naloxone compared with buprenorphine administered intramuscularly in postoperative patients.

Sixty patients suffering from moderate to severe pain following either orthopaedic or gynaecological surgery were treated with intramuscular buprenorphine (0.3 mg) or an intramuscular combination of buprenorphine (0.3 mg)/naloxone (0.2 mg) and the analgesic efficacy and safety of the two treatments was compared. The evaluation of efficacy showed that both treatments provided good analgesia which was apparent at the first assessment time (10 minutes) and continued for approximately 10 hours. Only seven patients suffered from unwanted side-effects with only drowsiness/sleepiness and nausea being reported by more than one patient. Over-all analysis of the results showed that there were no significant differences between the two treatments with regard to efficacy and safety.

Effect of speed of injection on induction of anaesthesia using propofol.

Sixty unpremedicated patients (30 male) were randomly allocated to three groups. They received an induction dose of propofol 2 mg kg-1 over 5, 20 or 60 s to a forearm vein. Anaesthesia was maintained with conventional inhalation anaesthetic agents. Anaesthesia was induced satisfactorily in all 20 of the patients in the 5-s group, in 19 of the patients in the 20-s group and in 18 of the patients in the 60-s group. The rate of injection had a significant influence on induction time. Mean induction time increased from 21.5 to 34.7 and 50.5 s, when injection time was increased from 5 to 20 to 60 s, respectively. Similar induction times were found in male and female patients. There was no significant difference between the groups, in depth of anaesthesia obtained--as assessed by the eyelash reflex. Mean arterial pressure decreased to the same extent in all three groups. Two minutes after induction, mean systolic arterial pressure was reduced by 15.1, 13.5 and 19.3 mm Hg in the 5-, 20- and 60-s groups, respectively, and mean diastolic arterial pressure by 10.3, 13.2 and 13.7 mm Hg. Heart rate changes were insignificant. Apnoea of more than 10 s duration was seen frequently in all three groups, but the results suggest that the incidence was not influenced by the rate of injection. Three patients experienced mild pain at the time of injection. No major adverse reactions occurred during or after anaesthesia.