[Coronary surgery at the Heart Center in Oslo 1989-98]. / Koronarkirurgi ved Hjertesenteret i Oslo 1989-98.

BACKGROUND: Coronary artery bypass grafting was performed in 5,658 consecutive patients during the period 1989-1998. Due to changes over time, both in patients' risk profile and surgical strategies, a review was undertaken to study trends and results after coronary artery bypass surgery. MATERIAL AND METHODS: Our database includes more than 160 variables per patient, covering preoperative risk factors, catheterization data, operative and postoperative results. These data form the basis for analysis over time. RESULTS: Median age increased for both genders, from 58 years to 64 years for males and 62.5 years to 69 years for females. The female proportion increased from 12.8% to 19.8%. A high operative risk profile was registered in 23.7% in 1989 compared to 61.8% in 1998. Heparin-coated extracorporeal equipment and blood cardioplegia were gradually introduced in routine practice. Despite higher age and operative risk profile the morbidity and hospital mortality (0.41% overall) remained nearly unchanged. INTERPRETATION: Due to continuous improvement of technical equipment and treatment strategies, coronary artery bypass surgery represents a safe option for both high and low risk patients.

Autotransfusion in coronary artery bypass grafting: disparity in laboratory tests and clinical performance.

OBJECTIVE: Autotransfusion during and after cardiac surgery is widely performed, but its effects on coagulation, fibrinolysis, and inflammatory response have not been known in detail. METHODS: Hemostatic and inflammatory markers were extensively studied in 40 coronary artery bypass patients undergoing a consistent intraoperative and postoperative autotransfusion protocol. An identical autotransfusion protocol was applied to 4916 consecutive coronary patients and the overall clinical results were evaluated in this large patient population. RESULTS: The autologous blood pooled before bypass remained nearly inactivated after storage. A slight elevation of thrombin-antithrombin complex and prothrombin fragment 1.2, as well as plasmin/alpha(2)-antiplasmin complex was found in the content of the extracorporeal circuit after surgery, indicating thrombin formation and fibrinolytic activity. Also some increase of beta-thromboglobulin was present. In the mediastinal shed blood, complete coagulation, as evidenced by the absence of fibrinogen, had taken place and all parameters described above were extremely elevated. However, no thrombin activity was detected. As for the inflammatory response, moderately increased levels of complement activation products, terminal complement complex, and interleukin-6 traced in the extracorporeal circuit reached very high levels in mediastinal shed blood. Autotransfusion of the residual extracorporeal circuit blood and the mediastinal drainage was followed by elevation of most of these markers in circulating plasma. On the other hand, no correlating harmful effects were recorded in the study patients or in the consecutive 4916 patients. Coagulation disturbances were rare and allogeneic transfusions were required in fewer than 4% of all patients. CONCLUSIONS: The hemostatic and immunologic systems were moderately activated in the autologous blood remaining in the extracorporeal circuit, whereas the mediastinal shed blood was highly activated in all aspects. However, autotransfusion had no correlating clinical side-effects and the subsequent exposure to allogeneic blood products was minimal.

[Cost savings with autotransfusion in connection with coronary surgery]. / Kostnadsbesparelse ved autotransfusjon i forbindelse med koronarkirurgi.

The main purpose of this study was to estimate the costs and savings related to a consistent autotransfusion programme. More than 8,000,000 ml of autologous blood or blood-containing fluid were collected from 3,637 consecutive patients undergoing coronary artery bypass and returned to the patients during and after the operation. Economic analyses revealed a price of NOK 13 million (approximately 2 million USD) for this amount of autologous blood, or NOK 3,500 (600 USD) per patient. In the present series the need for bank blood or blood products was modest, since 69 patients (1.9%) received packed red cells, with or without plasma, 76 patients (2.1%) were given plasma transfusions only, and 11 patients (0.3%) received platelets. Thus, 95.7% of the patients were not exposed to any homologous blood products during the stay in hospital. Absence of morbidity related to the low homologous blood transfusion rate was assumed to save costs substantially, although this saving was difficult to calculate in terms of currency. Post-operative complications were few, and the total in-hospital mortality rate was 0.4%.

Consistent non-pharmacologic blood conservation in primary and reoperative coronary artery bypass grafting.

Because much interest has been focused on blood conservation using different drugs and complicated blood cell processing devices, we analyzed our results with the use of a non-pharmacologic, simple and inexpensive program for blood salvage in 2326 patients undergoing myocardial revascularization. The material was divided into two groups: patients undergoing a primary coronary bypass operation (Group P, n = 2298) and a smaller subset of patients undergoing repeat coronary bypass operation (Group R, n = 28). At least one internal mammary artery was grafted in 99% of the patients, with supplemental saphenous vein grafts. Intraoperatively, autologous heparinized blood was removed before bypass and retransfused at the conclusion of extracorporeal circulation. The volume remaining in the extracorporeal circuit was returned without cell processing or hemofiltration. Autotransfusion of the shed mediastinal blood was continued hourly up to 18 h after surgery in all patients. The mean postoperative mediastinal drainage in group R was 543 +/- 218 ml, compared to 703 +/- 340 ml in Group P (P = 0.01). In Group R, 1 patient (3.6%) received packed red cells and no patients were given other homologous blood products, compared to 33 patients (1.4%) given red cells and 35 patients (1.5%) given plasma transfusion in Group P (NS). Thus, in total, 2257 patients (97.0%) were not exposed to any homologous blood products during hospitalization. Total hemoglobin loss was significantly higher in Group R, resulting in a mean hemoglobin concentration at discharge of 109 +/- 13 g/l, compared to 121 +/- 14 g/l in Group P (P = 0.0002).(ABSTRACT TRUNCATED AT 250 WORDS)

Tranexamic acid (Cyklokapron) is not necessary to reduce blood loss after coronary artery bypass operations.

The contribution of fibrinolysis to postoperative bleeding after cardiopulmonary bypass led to routine use of tranexamic acid, a potent antifibrinolytic drug, for a period of time. Two hundred patients undergoing elective coronary artery bypass operations were studied, one group of 100 patients given tranexamic acid (40 mg/kg) (group I) after bypass and one subsequent group of 100 patients (group II) serving as a control group. All patients were treated by the same team, and the groups were comparable in all major clinical parameters. The mean mediastinal drainage in group I was 565 +/- 239 ml versus 656 +/- 257 ml in group II. Univariate and multivariate analysis revealed statistical significance (p = 0.02) when corrected for body surface area. However, applying a consistent blood conservation protocol, including removal of autologous blood before bypass for retransfusion after bypass, returning of all oxygenator and tubing contents to the patients, and autotransfusion of the mediastinal shed blood up to 18 hours postoperatively, resulted in nearly identical hemoglobin concentration at discharge (119 +/- 14 gm/L in group I and 121 +/- 14 gm/L in group II). The prevalence of postoperative myocardial infarction included five patients in group I compared with one patient in group II. Although not statistically significant (p = 0.2), the difference is of concern. Tranexamic acid has a beneficial effect on reducing postoperative bleeding after coronary artery bypass operations. The routine use of the drug is not recommended, however, because its effect is a weak one, and it may be of potential hazard by precipitating thrombosis and eventual myocardial infarction.

Autotransfusion after open heart surgery: characteristics of shed mediastinal blood and its influence on the plasma proteases in circulating blood.

Fourteen patients undergoing open-heart surgery received intermittent or continuous postoperative autotransfusion of shed mediastinal blood (minimum 400 ml during 6 h after surgery) collected in the cardiotomy reservoir. Hematologic variables and changes in the coagulation, fibrinolytic and plasma kallikrein-kinin systems were investigated in the reservoir blood at the beginning and after 6 h of autotransfusion, and in patient blood during and after surgery and before and after autotransfusion. Autotransfusion volume ranged from 400 to 1200 ml per patient (median 482 ml). The reservoir blood had a median haemoglobin level of 93 and 74 g/l, a platelet count of 71 and 119 x 10(9)/l, and plasma haemoglobin level of 3110 and 4100 mg/l before and after 6 h of autotransfusion, respectively. Further examination of the reservoir blood showed that it had undergone extensive coagulation and fibrinolysis as well as a moderate activation of the kallikrein-kinin system. Despite these extensive alterations in the reservoir blood, no major change could be found in the circulating blood after autotransfusion, except for a moderate increase in plasma haemoglobin from 180 mg/l to 430 mg/l. The clinical safety and simplicity of this technique were confirmed for autotransfusion of shed mediastinal blood up to 1200 ml.

Elective coronary artery bypass surgery without homologous blood transfusion. Early results with an inexpensive blood conservation program.

Restriction of donor blood transfusions in cardiac surgery should reduce risks of infective contamination and antigenicity. We report a systemic, simple and inexpensive blood conservation program used for 121 consecutive patients who underwent elective coronary artery bypass surgery without need for homologous blood transfusion. The left internal mammary artery was grafted in all cases, in addition to saphenous vein grafts. Autologous, heparinized blood was removed intraoperatively, pre-bypass, and returned to the patient at conclusion of the extracorporeal circulation. The volume remaining in the oxygenator and the tubing set was returned without cell processing or hemofiltration. Using the hard-shell cardiotomy reservoir from the heart-lung machine, autotransfusion of the shed mediastinal blood was continued hourly up to 18 hours after surgery. The mean postoperative mediastinal bleeding was 551 +/- 206 ml, of which 505 +/- 218 ml was autotransfused. No re-exploration for bleeding was required and no homologous red-cell transfusions were given. Five patients each received 1-2 units of fresh frozen plasma because of prolonged bleeding time. Morbidity was low and mortality nil. At discharge the mean hemoglobin was 12.0 +/- 1.4 g/dl and the hematocrit 36.0 +/- 4.2%.

[Heart surgery without blood transfusion]. / Hjertekirurgi uten blodtransfusjon.

Blood conservation in open heart surgery has become mandatory in order to reduce the risk of viral contamination, and because of limited resources. We have performed 100 consecutive coronary artery bypass operations (13 women/87 men, aged 33-73 years, mean 58 years) without using homologous blood. A strict blood conservation programme was applied, with removal of autologous blood prebypass for retransfusion at the end of surgery, retransfusion of the heart-lung machine content to the patient, and autotransfusion of shed mediastinal blood in the postoperative period. All patients survived the operation and were extubated 1.6 hours (0-6) postoperatively. No patients needed resternotomy for bleeding, and no homologous blood was given. Five patients received 1-2 units of fresh frozen plasma because of coagulopathy. Mean hemoglobin was 12.0 g/100 ml and mean hematocrit was 36% at discharge from hospital. Elective coronary artery bypass surgery can be performed with little or no transfusions of homologous blood.

Coronary artery bypass surgery with minimal use of homologous blood. Effects of a simple and inexpensive blood conservation programme.

Restriction of donor blood transfusions in cardiac surgery should decrease the risk of infective contamination and antigenicity. Following a simple, systematic and inexpensive blood conservation program, we report on 250 consecutive patients undergoing elective coronary artery bypass surgery, 247 (98.6%) of whom did not need homologous blood transfusions. At least one internal mammary artery was grafted in all but one patient, in combination with saphenous vein grafts. Intraoperatively, autologous heparinized blood was removed before bypass and retransfused at the conclusion of extracorporeal circulation. The remaining volume of the oxygenator and tubing set was retransfused without any cell processing or hemofiltration. Using the hard-shell cardiotomy reservoir from the heart lung machine, autotransfusion of the shed mediastinal blood was continued hourly up to 18 h after surgery. The mean postoperative mediastinal bleeding was 622 +/- 287 ml, of which 589 +/- 296 ml was autotransfused. Five patients (2.0%) needed re-exploration for bleeding, and three of these received 1-4 units of homologous blood. No other patients needed red cell transfusions. Seven patients were given a mean of 2.6 units of fresh frozen plasma because of coagulopathy. Thus, altogether 240 patients (96%) were not exposed to any homologous blood products during their hospital stay. Morbidity was low. At discharge, the mean hemoglobin concentration was 12.0 +/- 1.4 g/dl and the mean hematocrit 36.0 +/- 4.2%. There were no deaths.