Comparison of the effects of albumin 5%, hydroxyethyl starch 130/0.4 6%, and Ringer's lactate on blood loss and coagulation after cardiac surgery.

BACKGROUND: Infusion of 5% human albumin (HA) and 6% hydroxyethyl starch 130/0.4 (HES) during cardiac surgery expand circulating volume to a greater extent than crystalloids and would be suitable for a restrictive fluid therapy regimen. However, HA and HES may affect blood coagulation and could contribute to increased transfusion requirements. METHODS: We randomly assigned 240 patients undergoing elective cardiac surgery to receive up to 50 ml kg(-1) day(-1) of either HA, HES, or Ringer's lactate (RL) as the main infusion fluid perioperatively. Study solutions were supplied in identical bottles dressed in opaque covers. The primary outcome was chest tube drainage over 24 h. Blood transfusions, thromboelastometry variables, perioperative fluid balance, renal function, mortality, intensive care unit, and hospital stay were also assessed. RESULTS: The median cumulative blood loss was not different between the groups (HA: 835, HES: 700, and RL: 670 ml). However, 35% of RL patients required blood products, compared with 62% (HA) and 64% (HES group; P=0.0003). Significantly, more study solution had to be administered in the RL group compared with the colloid groups. Total perioperative fluid balance was least positive in the HA group [6.2 (2.5) litre] compared with the HES [7.4 (3.0) litre] and RL [8.3 (2.8) litre] groups (P<0.0001). Both colloids affected clot formation and clot strength and caused slight increases in serum creatinine. CONCLUSIONS: Despite equal blood loss from chest drains, both colloids interfered with blood coagulation and produced greater haemodilution, which was associated with more transfusion of blood products compared with crystalloid use only.

Ventricular thrombus and subarachnoid bleeding during support with ventricular assist devices.

We report the case of a 23-year-old man with acute aortic valve insufficiency caused by endocarditis, who after emergency aortic valve replacement developed biventricular heart failure. The heart failure was treated with temporary assist devices. Subarachnoid bleeding and thrombus obstruction of the left ventricular outflow tract was detected. The postoperative course is presented with special emphasis on management of subarachnoid bleeding and the simultaneous use of anticoagulation necessary for ventricular assist devices.

Jugular venous bulb oxygen saturation depends on blood pressure during cardiopulmonary bypass.

BACKGROUND: Central nervous system dysfunction after cardiopulmonary bypass is frequent and can be caused by inadequate cerebral perfusion and oxygenation. METHODS: To test the effectiveness of cerebral autoregulation during cardiopulmonary bypass, we induced changes in the cerebral perfusion pressure by administering phenylephrine during moderate (29 degrees C) hypothermia. Using the Fick principle, we calculated relative changes in cerebral blood flow from changes in the jugular venous bulb oxygen saturation. RESULTS: Increasing the cerebral perfusion pressure (from 47 +/- 8.2 to 93 +/- 16 mm Hg) induced increases in the jugular venous bulb oxygen saturation by 4.9% and a calculated increase in the cerebral blood flow by 19.9%, strongly suggesting impaired cerebral autoregulation. CONCLUSIONS: Because cerebral autoregulation is impaired during cardiopulmonary bypass, phenylephrine is effective in increasing the cerebral blood flow and may contribute to the prevention of postoperative neurologic dysfunction, especially in patients who have a low jugular venous bulb oxygen saturation.

Target vessel revascularization without cardiopulmonary bypass in elderly high-risk patients.

BACKGROUND: Coronary artery bypass grafting in patients over 75 years is associated with high operative risk. Target vessel revascularization without cardiopulmonary bypass is a promising option for highly selected, older patients. However, the outcome remains uncertain. METHODS: We investigated 44 patients over 75 years, matched for preoperative risk and left ventricular function, who underwent coronary artery bypass grafting either with or without cardiopulmonary bypass (CPB). We analyzed patients characteristics, Parsonnet score, EuroSCORE, short as well as midterm outcome and quality of life (freedom from recurrence of angina, anti-anginal therapy, sf36 test). RESULTS: Perioperative mortality was higher in the patient group operated with CPB (15.9) as compared to patients operated without CPB (4.5%, p = 0.0226). Patients operated with cardiopulmonary bypass received more grafts (3.1 +/- 0.1) than patients operated without cardiopulmonary bypass (1.6 +/- 0.1, p = 0.0001) and and were more likely to undergo complete revascularization (with CPB 100%, without CPB 63.6%, p = 0.0010). Perioperative complications were more frequent and midterm survival was worse in the patient group operated with CPB (log rank p = 0.0228). Quality of life was comparable in both groups. CONCLUSIONS: The concept of incomplete target vessel revascularization of the culprit lesion seems to be a promising option for selected high-risk patients, predominantly due to lower perioperative mortality.

[Requirements and expectations for optimal volume replacement]. / Forderungen und Erwartungen an einen optimalen Volumenersatz.

A volume replacement should compensate a reduction in the intravascular volume and counteract a hypovolemia so that hemodynamics and vital functions can be maintained. For this therapy, a physiologically-based solution comprising both osmotically and colloid osmotically active components should be administered. A consensus is proposed for this purpose which takes into consideration the following aspects: The optimum colloid, the questionable use of albumin, the physiological electrolyte pattern encompassing sodium, potassium, chloride and phosphate and their contributions to osmolality, an eventual addition of glucose, the physiological acid-base status with bicarbonate or alternately with metabolisable anions, and the importance of a clear declaration of all ingredients. The consensus distinguishes between compulsory requirements derived from evidence-based medicine and physiological data and the potential expectations of an optimal volume replacement, including well-grounded wishes and aspirations for the future.

Performance of proportional and continuous nitric oxide delivery systems during pressure- and volume-controlled ventilation.

We have evaluated the effect of delivering nitric oxide using a continuous flow system (CFS) or two commercially available proportional gas injection systems (PGIS), Nodomo (Dräger, Lübeck, Germany) and Pulmonox-Mini (Messer Griesheim Austria, Gumpoldskirchen, Austria) on measured and simulated concentrations of nitric oxide. Nitric oxide concentration was measured in a bench test at five sites in the inspiratory breathing system during volume- or pressure-controlled ventilation and mathematically simulated using a mixing chamber model. For a target concentration of 10 parts per million (ppm) at the "Y" piece, simulated nitric oxide concentrations were 1.9-139 ppm for CFS, 0.3-22 ppm for the Nodomo and 0.0-31 ppm for the Pulmonox-Mini near the nitric oxide administration site. However, peak concentrations decreased rapidly along the inspiratory system. Measured and simulated variations depended on the nitric oxide delivery system, site of measurement and tidal volume. Measured variations were four times smaller in the Nodomo than in the Pulmonox-Mini and CFS. As inappropriate mixing may occur even with PGIS, nitric oxide should probably not be administered near the "Y" piece.

Alterations in the number of circulating leucocytes, phenotype of monocyte and cytokine production in patients undergoing cardiothoracic surgery.

Changes in the differential blood cell count, monocyte phenotype and the cytokine plasma levels in a group of seven patients with cardiac surgery/cardiopulmonary bypass (CPB) and nine patients with thoracic surgery/without CPB, both receiving identical opioid-based anaesthetic technique, were assessed. A significant reduction in the number of circulating lymphocytes and monocytes was observed after anaesthesia and surgery. Interestingly, at the end of surgery as well as 1 day post-surgery a marked increase in the number of granulocytes was noted. General anaesthesia and surgery caused a significant reduction of HLA-DR and CD11c/CD18 molecules, starting immediately after induction of anaesthesia, and an increase of CD64 at day 1 after anaesthesia. The use of a CPB was followed by a significant reduction of CD32, CD16, CD54 and HLA-ABC antigens expression at the end of surgery. One day after surgery these parameters returned nearly to baseline values with the exception of CD54. A monocyte subpopulation, characterized by low CD14, high CD16 and HLA-DR expression (CD14+CD16+HLA-DR++) was found in both groups at each time point, and the percentage of this cell subset decreased from baseline to 24 h. The plasma concentrations of IL-6 and IL-10 increased considerably during CPB. No dynamic changes of IL-1 level due to surgery or CPB were found. We conclude that anaesthesia as well as the use of CPB induced profound alterations in the number of circulating leucocytes, and in the phenotype of monocyte and cytokine production.