Perfusion
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Randomized Controlled Trial Comparative Study
Comparison of two infusion rates of antithrombin concentrate in cardiopulmonary bypass surgery.
Antithrombin concentrate (AT) is used to treat heparin resistance (HR) in cardiac surgery. It is usually given slowly due to the fear of anaphylaxis. This may delay cardiac catheterisation and the start of cardiopulmonary bypass (CPB). HR is often defined as the failure to reach or maintain a target activated clotting time (ACT) despite a standard dose of heparin. It is not generally possible to predict which patients will display HR, although there are known risk factors. Routine early administration of AT before heparinisation is probably not cost-effective. Infusing AT relatively quickly after demonstrating HR may be more cost-effective, while not delaying surgery. The aim of this study is to investigate the safety and side effects of a faster infusion of AT. ⋯ AT can be infused at a rate of 250 IU/min. This is faster than the current recommendation of 100 IU/min. This rate of infusion allows restricting AT infusion to those patients who display HR, without delaying surgery. Optimal anticoagulant therapy for CPB probably includes point-of-care measurement of ACT and plasma AT and small, but rapid, infusions of AT in heparin-resistant patients.
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Randomized Controlled Trial Comparative Study
Comparison of the effect of 6% hydroxyethyl starch and gelatine on cardiac and stroke volume index: a randomized, controlled trial after cardiac surgery.
The objective of this study was to find out the effect of various doses of hydroxyethyl starch (HES), gelatine or Ringer's acetate on cardiac and stroke volume index after cardiac surgery. ⋯ Mean (SD) cardiac and stroke volume indices were greater in the HES group [2.8 L·min(-1)·m(-2) (0.7), 34.1 (6.7) ml·m( -2)] than in the gelatine group [2.2 L·min(-1)·m( -2) (0.6), 25.8 (7.2) ml·m(-2)] after completion of 7 mL·kg(-1) of study solution. At this stage, the effect of gelatine did not differ from Ringer's acetate. After completion of 14 mL·kg(-1) and 21 mL·kg(-1) of colloids, similar cardiac and stroke volume indices were observed and the haemodynamic response was better in both colloid groups than in the Ringer's acetate group. No differences between groups were detected on the first postoperative morning. In the early postoperative phase after cardiac surgery, the effect of a single dose of HES solution on the haemodynamics was superior to the effect of gelatine or Ringer's acetate. However, after repeated administration of the study solutions, the haemodynamics in the two colloid groups appeared to be similar, but superior to the Ringer's acetate group.
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Randomized Controlled Trial
Effect of increased pump flow on hepatic blood flow and systemic inflammatory response following on-pump coronary artery bypass grafting.
Reduced organ perfusion during cardiopulmonary bypass (CPB) is responsible for morbidity associated with cardiac surgery. Non-pulsatile flow and hypothermia during CPB have been shown to cause reduced perfusion. During CPB, cardiac output is directly proportional to the pump flow rate. Therefore, we hypothesised that increasing pump flow during hypothermic CPB would improve organ perfusion and reduce the inflammatory response in the post-operative period. ⋯ Higher pump flows during hypothermic CPB increase hepatic blood flow. There was a trend towards attenuation of post-operative inflammatory response; however, larger studies will be needed to confirm these findings.
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Randomized Controlled Trial
Clinical relevance of ventilation during cardiopulmonary bypass in the prevention of postoperative lung dysfunction.
The current clinical study is the continuity of previous experimental findings in which ventilation during cardiopulmonary bypass (CPB) prevented reperfusion injury of the pulmonary arterial tree as demonstrated by preservation of vasorelaxation to acetylcholine (ACh) in swine. The aim of this prospective randomized study is to determine: 1) if ventilation during CPB prevents the selective endothelium-mediated lung dysfunction in humans and, 2) the clinical relevance of ventilation during CPB. Forty patients scheduled for primary coronary artery bypass grafting (CABG) were randomized into two groups: Group 1: Usual care (defined as no ventilation during CPB) and Group 2: CPB with low tidal volume ventilation (3 ml.kg(-1)) without positive end expiratory pressure (PEEP). ⋯ The ventilated group appears to obtain a greater vasorelaxation to ACh, as shown by the more pronounced change in PVRI when compared to the non-ventilated group. However, the difference in PVRI between the two groups was not statistically significant after weaning (p= 0.32) and 1hr after CPB (p= 0.28). Contrary to our hypothesis and due to larger than expected variability in the data, the hemodynamic and clinical changes seen were not statistically significant.
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Randomized Controlled Trial
Effect of subzero-balanced ultrafiltration on postoperative outcome of patients after cardiopulmonary bypass.
To evaluate the effect of a new ultrafiltration technique - subzero-balanced ultrafiltration technique - on early postoperative outcomes of adult patients undergoing cardiac operations with cardiopulmonary bypass. ⋯ Subzero-balanced ultrafiltration during cardiopulmonary bypass can effectively decrease the patients' hospital morbidity and the volume of blood transfusion: it also may promote early postoperative recovery of patients. Routine application of subzero-balanced ultrafiltration during adult cardiac operations should not be necessary, but the technique should be compared to other techniques, e.g. MUF, in further studies.