ABSTRACT: Fat embolization to the brain is a potential problem in cardiac surgery, assumed to originate from retransfused pericardial suction blood. Our aim was to measure the fat content in pericardial suction blood and to determine how it can be reduced by simple spontaneous density separation and surface absorption.
Pericardial suction blood was collected during routine coronary bypass procedures and analyzed for blood-suspended fat and plastic surface binding. A single-chamber bag (n = 10) was compared with a fat-reducing system having a stacked 2-chamber design (n = 10). The fat-reducing system was also tested experimentally (n = 12) with heat-extracted liquid wound fat (1.25%) mixed with mediastinal drain blood.
Pericardial suction blood contained 1.5 mL (0.63/2.19) of fat suspended in 418 mL (269/631) of blood (median and quartiles). Surface-bound fat accounted for 24% (12/35). Experimental analysis of the new system revealed an 83% (71/92) fat-reduction rate (P < .001). This rate was confirmed under clinical conditions, suggesting 80% reduction (72/86; P = .001). The fat-reducing system also gave a small but significant red blood cell concentrating effect (P = .001).
It was confirmed that pericardial suction blood contains fat, possibly having an embolic potential. The new system allowed fat to separate by density while pericardial suction blood was temporally retained and incubated. A significant portion of fat adheres to the plastic surface, which added to the reduction. The method appeared efficient. It is proposed that pericardial suction blood should be collected during surgery to evaluate the need for retransfusion and to allow fat reduction.
The Journal of thoracic and cardiovascular surgery 08/2007; 134(2):366-72. · 3.41 Impact Factor
Perfusion 10/2005; 20(5):243-8. · 0.92 Impact Factor
ABSTRACT: Pericardial suction blood (PSB) contains mediastinal liquid wound fat with an embolic potential to cause brain damage after cardiopulmonary bypass (CPB). The aims were to measure how fat separates spontaneously from blood by density and how temperature and fat surface adhesion affect the results under experimental conditions. Human liquid fat was heat-extracted from retrieved pericardial fat tissue of coronary artery bypass graft (CABG) patients (n = 10). Human fat or soya oil, 5% and 10%, respectively, were mixed with postoperatively shed mediastinal blood (n = 20). The mixture was loaded into a temperature-controlled (37 degrees C, 20 degrees C, 10 degrees C) vertical separation column. At 1, 2.5, 5 and 10 minutes, the blood was collected in five fractions, representing layers of density separation, followed by centrifugation. Human fat solidified at 8 degrees C. Soya oil remained liquid below 0 degrees C. Soya oil separated fast in water, but was slower in blood. At 10 minutes and 37 degrees C 73 +/- 6% of added soya oil was found in the top 20% fraction. Human fat at 37 degrees C behaved similarly to soya oil, with 58 +/- 2% separation at 10 minutes. However, at lower temperatures the density separation became less efficient (p < 0.001), whereas human fat more effectively adhered to the walls of the column, which added to the removal. In total, 66%-78% of the human fat was removed, depending on temperature. In conclusion, fat in PSB can be reduced by simple density separation and surface adhesion while it is temporarily retained from the CPB circuit.
Perfusion 03/2003; 18(1):39-45. · 0.92 Impact Factor
ABSTRACT: To investigate situations in cardiac surgery when transfusions are sometimes used for indications other than to compensate for surgical bleeding.
Cardiac surgery unit at a university teaching hospital.
Patients scheduled for coronary artery bypass graft surgery (n = 2,469).
A subgroup of patients with surgical bleeding of < or = 400 mL (n = 982) was selected to identify mechanisms leading to perioperative erythrocyte transfusion.
Bleeding of >400 mL triggered transfusion. At less than this bleeding volume, other indications were noted: unstable angina, use of blood cardioplegia, and bad surgical outcome, such as inotropic support. After exclusion of these predictors and anemic patients, the strongest predictors were female gender (p < 0.001), weight < or = 70 kg (p < 0.001), cardiopulmonary bypass (CPB) time > or = 90 minutes (p = 0.002), CPB cooling < or = 32 degrees C (p = 0.038), and advanced age (p < 0.001). Results from a more detailed study of medical records showed that within its normal concentration range, the operating room-transfused patients had lower hemoglobin levels. When followed postoperatively in the intensive care unit and ward, these patients continued to receive more transfusions (p < 0.05) even though their bleeding in the intensive care unit did not differ from the control subjects.
Some patients are transfused because of institutional bias of an anticipated need rather than for true surgical bleeding. A concern of hemodilution from standard CPB circuits suggests a possible advantage with low-priming volume for smaller adult female patients.
Journal of Cardiothoracic and Vascular Anesthesia 10/2002; 16(5):539-44. · 1.64 Impact Factor
ABSTRACT: Neurologic dysfunction after cardiopulmonary bypass might be due to arterial microembolization. Pericardial suction blood is a possible source of embolic material. Our aim was to determine the capillary-pore flow ability of pericardial suction blood.
Pericardial suction blood from patients undergoing coronary bypass was collected, and pericardial suction blood and venous blood were sampled at the end of cardiopulmonary bypass and before reinfusion of pericardial suction blood. Pericardial suction blood was (n = 10) or was not (n = 10) prefiltered through a 30-microm cardiotomy screen filter before capillary in vitro analysis. Additionally, in 8 patients the plasma viscosity was measured, and in 5 of these patients, pericardial suction blood capillary deposits were evaluated by using a microscopy-imprint method and fat staining. Capillary flow was tested through 5-microm pore membranes. Tested components were plasma, plasma-eliminated whole-blood resuspension, and leukocyte/plasma-eliminated erythrocyte resuspension. Initial filtration rate and clogging slope expressed the blood-to-capillary interaction.
The plasma-flow profile of pericardial suction blood was highly impaired, with a 47% reduction in initial filtration rate (P <.001) and a 142% steeper clogging slope flow deceleration (P <.01). This difference was not due to a change in pericardial suction blood viscosity, such as by free hemoglobin, which corresponded to 5.7% of the erythrocytes. There were no differences in resuspended whole blood or erythrocytes. The cardiotomy filter had no effect. Microscopy suggested the presence of capillary fat deposits in pericardial suction blood that were not seen with venous plasma (P <.05). The pericardial suction blood volume was 458 +/- 42 mL and contained 95.6 +/- 9.3 g/L hemoglobin.
The pericardial suction blood plasma capillary flow function was highly impaired by liquid fat. Pericardial suction blood hemoglobin appears worth recovering after fat removal, despite profound hemolysis.
Journal of Thoracic and Cardiovascular Surgery 08/2002; 124(2):377-86. · 3.41 Impact Factor