Cardiorespiratory effects of venous lipid micro embolization in an experimental model of mediastinal shed blood reinfusion

<p>Abstract</p> <p>Background</p> <p>Retransfusion of the patient's own blood during surgery is used to reduce the need for allogenic blood transfusion. It has however been found that this blood contains lipid particles, which form emboli in different organs if the blood is retransfused on the arterial side. In this study, we tested whether retransfusion of blood containing lipid micro-particles on the venous side in a porcine model will give hemodynamic effects.</p> <p>Methods</p> <p>Seven adult pigs were used. A shed blood surrogate containing 400 ml diluted blood and 5 ml radioactive triolein was produced to generate a lipid embolic load. The shed blood surrogate was rapidly (<2 minutes) retransfused from a transfusion bag to the right atrium under general anesthesia. The animals' arterial, pulmonary, right and left atrial pressure were monitored, together with cardiac output and deadspace. At the end of the experiment, an increase in cardiac output and pulmonary pressure was pharmacologically induced to try to flush out lipid particles from the lungs.</p> <p>Results</p> <p>A more than 30-fold increase in pulmonary vascular resistance was observed, with subsequent increase in pulmonary artery pressure, and decrease in cardiac output and arterial pressure. This response was transient, but was followed by a smaller, persistent increase in pulmonary vascular resistance. Only a small portion of the infused triolein passed the lungs, and only a small fraction could be recirculated by increasing cardiac output and pulmonary pressure.</p> <p>Conclusion</p> <p>Infusion of blood containing lipid micro-emboli on the venous side leads to acute, severe hemodynamic responses that can be life threatening. Lipid particles will be trapped in the lungs, leading to persistent effects on the pulmonary vascular resistance.</p

Coronary artery surgery: cardiotomy suction or cell salvage?

Coronary artery bypass grafting (CABG) today results in what may be regarded as acceptable levels of blood loss with many institutions avoiding allogeneic red cell transfusion in over 60% of their patients. The majority of cardiac surgeons employ cardiotomy suction to preserve autologous blood during on-pump coronary artery bypass surgery; however the use of cardiotomy suction is associated with a more pronounced systemic inflammatory response and a resulting coagulopathy as well as exacerbating the microembolic load. This leads to a tendency to increased blood loss, transfusion requirement and organ dysfunction. Conversely, the avoidance of cardiotomy suction in coronary artery bypass surgery is not associated with an increased transfusion requirement. There is therefore no indication for the routine use of cardiotomy suction in on-pump coronary artery surgery

Laser evaporation as a source of small free-radicals

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Use of heparin-bonded circuits in cardiopulmonary bypass improves clinical outcome

OBJECTIVE: The use of heparin-coated surfaces in cardiopulmonary bypass has been shown to decrease the inflammatory response imposed by the contact between blood and artificial surfaces. One would expect this reaction to improve clinical outcome. However, this has been difficult to verify. This investigation is based on an aggregation of two randomized studies from our institution and highlights possible effects of heparin coating on a number of clinically oriented parameters. DESIGN: Departmental analysis of patients subjected to coronary artery bypass surgery using heparin-coated circuits. Cardiopulmonary bypass was employed using either the Carmeda or Duraflo heparin coatings compared with a control. The systemic heparin dose was reduced in the heparin-coated groups (ACT &gt; 250 s) vs control group patients (ACT &gt; 480 s). The effects of heparin coating related to clinical outcome were studied. RESULTS: The use of heparin-coated circuits reduced the mean length of stay in hospital from 7.8 +/- 2.5 to 7.3 +/- 1.8 days (p = 0.040) and postoperative ventilation time from 9.7 +/- 9.2 to 8.2 +/- 8.5 h (p = 0.018), blood loss 8 h post surgery from 676 +/- 385 to 540 +/- 245 ml (p = 0.001), individual perioperative change of haemoglobin loss (p = 0.001), leukocyte count (p = 0.000) and creatinine elevation (p = 0.000), proportion of patients exposed to allogenous blood transfusions 39.2 vs 23.9% (p = 0.001), postoperative coagulation disturbances 4.4 vs 0.4% (p = 0.006), postoperative deviations from the normal postoperative course 47.2 vs 36.7% (p = 0.035), neurological deviations 9.4 vs 3.9% (p = 0.021) and atrial fibrillation 26.4 vs 18.0% (p = 0.041). No effects were found with respect to perioperative platelet count, postoperative fever reaction and 5-year survival. CONCLUSION: Based on several indicators, the use of heparin coating in cardiopulmonary bypass is associated with improved clinical results.</p

Neurological and general outcome in low-risk coronary artery bypass patients using heparin coated circuits

Objective: The clinical significance of heparin coating in cardiopulmonary bypass has previously been investigated. However, few studies have addressed the possible influence on brain function and memory disturbances. Methods: Three hundred low-risk patients exposed to coronary bypass surgery were randomised into three groups according to type of heparin coating: Carmeda Bioactive Surface, Baxter Duraflo II and a control group. Outcome was determined from a number of clinically oriented parameters, including a detailed registry of postoperative deviations from the normal postoperative course. Brain damage was assessed through S100 release and memory tests, including a questionnaire follow-up. Results: Clinical outcome was similar for all groups. Blood loss (Duraflo only), transfusion requirements and postoperative creatinine elevation were reduced in the heparin-coated groups. A lower incidence of atrial fibrillation was noted in the Duraflo group. Heparin coating did not uniformly attenuate the release of S100 or the degree of memory impairment. Conclusions: Cardiopulmonary bypass (CPB) with heparin coating and a reduced dose of heparin seems to be safe. Clinical outcome and neurological injury seem not to be associated with type of heparin coating used for CPB. However, blood loss and transfusion requirements may be reduced.</p