Perfusion
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Randomized Controlled Trial Comparative Study Clinical Trial
A comparison of albumin, polygeline and crystalloid priming solutions for cardiopulmonary bypass in patients having coronary artery bypass graft surgery.
This study was designed to assess the effect of different prime solution compositions on a patient's fluid balance, transfusion requirements, renal function and haemodynamic stability over the first 24 hours postbypass. Ninety-three patients presenting for first-time coronary artery bypass graft (CABG) surgery were randomly allocated to receive one of three prime solutions for the CPB pump: albumin (4.6%) + Plasmalyte (Group A, n = 32), polygeline (Hemaccel) + Plasmalyte (Group P, n = 29), or crystalloid (Plasmalyte) alone (Group C, n = 32). Patients, anaesthetists, surgeons and intensive care unit (ICU) staff were all blinded as to the solution type. ⋯ Our results show that, in this patient population, there is no advantage in using a colloid-based prime solution over a purely crystalloid solution from a haemotologic or haemodynamic point of view for the first 24 hours after CPB. There appears to be an increase in extracellular fluid (ECF) retention in Group C, but this caused no related problems in the study period. On the other hand, diuretics (frusemide) needed to be given significantly less often in these patients to offset oliguria.
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Randomized Controlled Trial Clinical Trial
The combination of mannitol and albumin in the priming solution reduces positive intraoperative fluid balance during cardiopulmonary bypass.
During cardiopulmonary bypass (CPB) an adequate reservoir volume is maintained by the addition of crystalloid, colloid or packed cells to the reservoir. This volume contributes to the overall perioperative positive fluid balance. ⋯ There was a large and highly significant reduction in volume of fluid added to the reservoir during CPB (2137 +/- 1499 ml versus 144 +/- 230 ml), the fluid balance during bypass, including prime volume (3236 +/- 650 ml versus 5876 +/- 1465 ml), and perioperative fluid balance (4470 +/- 936 ml versus 7023 +/- 1760 ml) in the group receiving both mannitol and albumin in the pump prime compared with the group receiving only lactated Ringer's solution. There were no differences between the groups with respect to both measured indices of oxygenation measured on return to ICU (alveolar-arterial oxygen tension difference (DA-aO2) or arterial oxygen tension to inspired oxygen fraction ratio (PaO2/FiO2), or time from ICU admission to extubation.
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The relationship between oxygen delivery (DO2) and uptake (VO2) has been studied during moderately hypothermic cardiopulmonary bypass (CPB) in 15 patients undergoing myocardial revascularization. As soon as nasopharyngeal temperature was lowered to 32 degrees C, blood flow was decreased from 2.4 to 2.0 l/min/m2. Arterial and mixed venous blood gas analyses were performed five and eight minutes later and DO2 and VO2 were calculated; VO2 stabilized in five minutes after changing blood flow and neither DO2 nor VO2 values changed three minutes later (DO2: 217 +/- 19 versus 215 +/- 17 ml/min/m2; VO2: 63 +/- 12 versus 66 +/- 14 ml/min/m2). ⋯ Consequently, lower VO2 values suggest inadequate oxygen supply to tissues. Critical DO2 at 32 degrees C is lower than 283 ml/min/m2 in 97.5% of patients. Finally, arterial vasoconstriction does not seem to play a significant role in tissue hypoperfusion.
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Randomized Controlled Trial Clinical Trial
The haemostatic effectiveness of autologous platelet rich plasma sequestered after heparin administration and institution of cardiopulmonary bypass.
Preoperative harvesting and postoperative reinfusion of autologous platelet rich plasma (PRP) has been reported to decrease blood loss as well as the requirement for homologous blood transfusion following cardiopulmonary bypass (CPB). We have developed a technique of intraoperative PRP sequestration which occurs during the initial period of CPB after the patient's circulation is supported and heparin has been given (PRP+). This process does not require any additional hardware, personnel or expense and it is performed without difficulty or complication. ⋯ Furthermore, more homologous haemostatic components (platelets/fresh frozen plasma) were required in the control group. We have demonstrated that collection of autologous PRP+ after administration of heparin does not interfere with its haemostatic effectiveness compared with PRPc prepared before the initiation of bypass. Moreover, this can be performed universally in haemodynamically unstable patients without any additional costs.