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The Hemochron Rx/Dx uses an ACT and a heparin response tube to calculate the heparin dose to identify heparin sensitive/resistant patients. We evaluated the Rx/Dx system in 37 patients to determine if the ACT after the predicted heparin loading dose was adequate to initiate CPB. The mean heparin dose calculated by the Rx/Dx was 31,700 IU +/- 8,700 IU (370 IU/kg) with a mean post ACT of 463 +/- 124 sec. Our standard heparin dose (400 IU/kg) would have given an additional 2,800 IU over the Rx/Dx. Four patients (6.5%) were predicted to be heparin sensitive and all four achieved an ACT over 450 sec. Twenty-one patients (56.8%) were predicted to be resistant and yet failed to raise the ACT over 450 sec in 17 (81.0%). Twelve patients (32.4%) were predicted to have a normal heparin response, and four (33.3%) did not achieve an ACT over 450 sec. In all, 21 patients (56.8%) did not achieve an ACT greater than 450 sec. Each institution should evaluate their heparin loading dose and the resultant ACT. In this study, we found the number of times the Rx/Dx system did not raise the ACT over 450 sec too great to justify the additional expense.

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BACKGROUND: The objective of this study was to determine the significant differences in preoperative and operative characteristics, and postoperative outcomes in patients having coronary artery bypass grafting (CABG) who are smokers and in those who are not smokers. METHODS: Data were collected prospectively in all (2916) patients having their first CABG. The patients were cared for in a regional medical center by private physicians. No operations were denied because of smoking status. Smokers differed from nonsmokers in several characteristics. RESULTS: Analysis of morbidity and mortality showed no instance in which smokers fared worse than nonsmokers. Stepwise logistic regression analysis showed that smoking was not predictive of mortality. Smoking was not predictive of morbidity except that it was predictive of less probability of need for intra-aortic balloon pump (7.5% in nonsmokers and 4.7% in smokers). We then created groups of smokers and nonsmokers that were individually matched for age and sex. Analysis of the matched groups of smokers and nonsmokers showed that there was no significant difference in the incidence or magnitude of preoperative and operative factors except that recent myocardial infarction was more common in smokers. Nonsmokers had greater weight, body mass index (obesity), and ejection fraction. There was no difference in smokers and nonsmokers in mortality or morbidity at the 99% confidence level. CONCLUSION: We conclude that there is no need to delay CABG for the patients who are smokers.

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The mechanisms and pathophysiology of perioperative neurologic injury are reviewed. The principle mechanisms of the ischemic injury are gaseous and particulate emboli and hypoperfusion caused by cerebrovascular occlusive disease. The contribution of the cardiopulmonary bypass circuit to the development of ischemic injury is discussed. The important role of the surgeon in preventing particulate and gaseous microemboli and macroemboli is described and techniques for avoiding hypoperfusion in the presence of occlusive cerebrovascular disease are presented. Patients at greatest risk of perioperative neurologic injury are elderly patients with atherosclerotic aorta, cerebrovascular disease, and previous neurologic abnormalities. The pump oxygenator may be the cause of neurologic injury by generation of emboli, hypoperfusion, and perfusion accidents. The principles of perfusion safety are presented. Massive air embolization may occur from the heart-lung machine or from the heart. Methods of preventing massive air embolus including techniques of bypass and air removal from the heart are discussed. The management of massive air embolus is thoroughly described. The detection of cerebrovascular disease is discussed and the management of the patient with cerebrovascular disease described. Atherosclerosis of the ascending aorta is a major risk factor for perioperative neurologic injury. Methods of detection and management are thoroughly described. Prevention of embolization from intracardiac debris and clot is described.

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BACKGROUND: Women have been found to have greater mortality from coronary artery bypass grafting than men. Uncertainty exists regarding the causes of the differences in outcomes between men and women after coronary artery bypass grafting. METHODS: From a database of 2,569 patients having coronary bypass grafting we have determined factors that contribute to poorer outcomes in women compared with men. RESULTS: Women were found to have greater mortality, postoperative bleeding, and postoperative pulmonary failure than men (p < 0.05). There was no significant difference between men and women in postoperative renal failure, postoperative infection, postoperative stroke, or intraaortic balloon pump (p = not significant). Patient factors other than sex accounted for all the significant predictors (stepwise logistic regression) of mortality, postoperative bleeding, postoperative renal failure, postoperative pulmonary failure, postoperative stroke, need for intraaortic balloon pump, and postoperative infection (p < 0.05). Poorer outcomes in women are associated with greater need for transfusion during operation. Diabetes is predictive of renal failure and stroke. CONCLUSIONS: Mortality and morbidity is less in men despite their higher preoperative creatinine level, greater incidence of reoperation, lower ejection fraction, and more common atherosclerosis of the ascending aorta.

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We compared the preoperative status, operative factors, and postoperative outcomes among patients having mitral valve operations with three atrial incisions. The incisions were right lateral (n = 66), superior septal (n = 46), and transseptal (n = 37). Differences in patient and operative factors among the groups were not predictors of adverse postoperative outcomes with multiple regression analysis. Postoperative pulmonary failure was less common in the superior septal group. Patients in the superior septal group more commonly required permanent pacemakers than those in the right lateral group. In patients with sinus rhythm before operation, sinus rhythm had returned before hospital discharge more commonly in those in the right lateral group (35 of 44, 80%) than in those in the superior septal group (18 of 28, 46%) or in the transseptal group (9 of 13, 69%). With multiple regression analysis the type of atrial incision was not a predictor of postoperative pulmonary failure or need for permanent pacemaker. Right lateral and transseptal atrial incisions were predictors of retention of sinus rhythm after operation. We conclude that the results of superior septal incision are comparable with those of other incisions except for a slightly greater risk of loss of sinus rhythm. One must weigh the technical advantages of the superior septal incision against the risk of loss of sinus rhythm.

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For surgical bleeding problems, the cell saver has been used to return shed blood; however, overuse can lead to a deficit in coagulation factors. Its usefulness has gained widespread use in many surgical settings. The hemoconcentrator can aid in raising the hematocrit level while reducing blood utilization where large blood volume and/or large amounts of irrigation are returned to the perfusion circuit. The hemoconcentrator returns red blood cells without removing coagulation factors, unlike the cell saver. In order to determine which method of returning residual blood from the cardiopulmonary bypass circuit is more desirable, blood samples were drawn both pre and post transfusion from 15 cell saver patients, and 14 hemoconcentrator patients. Twelve hour blood loss was recorded in 40 patients within each group. The fibrinogen, platelet count, total protein, albumin and white blood cell count were similar between the two groups, as was the blood loss. The only significant differences found were the post red blood cell count, post hemoglobin, and the delta hematocrit, all being higher in autotransfusion group. In conclusion, returning blood through the hemoconcentrator in the average adult perfusion circuit was not able to significantly raise certain coagulation parameters, nor reduce postoperative bleeding.

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We compared the preoperative, operative, and postoperative characteristics of patients who required balloon pumps after coronary artery bypass graft procedures to determine the relative risks of femoral and aortic insertion. The balloon pump was inserted into the ascending aorta when femoral insertion was not possible because of occlusive disease or small femoral arteries. Femoral insertion was performed in 81 patients and aortic insertion in 42 patients. Patients with aortic insertion were more likely to be small and female (p < 0.05) and were more likely to have carotid bruits and a history of strokes or transient ischemic attacks (p < 0.05). Death was more common in the patients with aortic insertion (18/42, 42.9%) than in those with femoral insertion (19/81, 23.4%) (p < 0.05), as calculated with single regression analysis. Route of insertion was not a predictor of operative death, according to multiple regression analysis. Leg complications were more common in patients with femoral artery insertion (23/81, 28.4%) than in those with aortic insertion (0/42, 0.0%) (p < 0.05). No sternal complications occurred in either group. New neurologic abnormalities were not significantly different between the patients with aortic and femoral insertion. Aortic insertion is a safe alternative to femoral insertion of intraaortic balloon pumps and is associated with fewer leg complications in small or diseased iliac and femoral arteries. The greater mortality rate with aortic insertion is related to greater comorbidity rate in these patients.

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Achieving sterilization of the postpneumonectomy space and bronchial healing may be difficult when active granulomatous infection of the pleural space and lung parenchyma is present at the time of operation. Three patients with chronic bronchopleural fistula, fungal empyema, and fungal cavities of the remaining ipsilateral lobe were managed with one-stage completion pneumonectomy and modified eight-rib thoracoplasty. Two patients had infection with Aspergillus fumigatis and 1 patient had Coccidioides immitis. Two patients had received mediastinal radiation after prior upper lobectomy for carcinoma of the lung. Two patients were having massive hemoptysis at the time of pneumonectomy. Eight-rib thoracoplasty with suturing of the intercostal muscles to the bronchial stump was performed on all patients. In 2 patients a mass closure of hilar vessels and bronchus was used because of inability to individually close the vessels and bronchus due to ligneous scarring of the hilum. Antibiotic and antifungal irrigations into the operative area were used postoperatively. Chest tubes were left in place 6 to 8 weeks. All wounds healed primarily. Patients were alive without recurrent local infection or tumor at follow-up 3 to 13 years postoperatively.

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Bacterial infection (Salmonella enteritidis) of left ventricular true and false aneurysm in a 62-year-old man was followed by septic saddle embolus. The septic saddle embolus was removed and the aneurysm was later resected with coronary bypass grafting. The patient is alive with satisfactory function over 5 years postoperatively.

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New information on cardiopulmonary bypass continues to be produced by investigators from many disciplines. Investigations are related to problems and complications resulting from use of the heart-lung machine. The relationship of perfusion and pressure during bypass in brain, kidney, and other organs is the subject of several reports. The studies confirm that low flow and pressure are safe with hemodilution and hypothermia. Investigations related to the pH stat and alpha stat blood gas schemes are sometimes inconclusive, but significant observations favor the use of the alpha stat blood gas scheme. The complications of choreoathetosis in pediatric patients appears to be related to low levels of hypothermia. Studies continue to show the many adverse effects of cardiopulmonary bypass on platelets, leukocytes, and the complement system. The minimum acceptable activated clotting time during cardiopulmonary bypass may be less than 400 seconds. Other authors address the complications of protamine infusion and heparin-induced thrombocytopenia.

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We have performed coronary bypass grafting in 25 patients 80 years of age or more. The patients' preoperative conditions were characterized by recent myocardial infarction (16/25, or 64%), obesity (15/25, or 60%), hypertension (14/25, or 56%), and left ventricular dysfunction (21/25, or 84%). There were no deaths in the hospital or within 30 days of operation (0/25, or 0%). Postoperative complications occurred in five cases (20%). Complications were leg incision infection (2/25, or 8%), urinary tract infection (1/25, or 4%), stroke (1/25, or 4%), and transient neurologic deficit (1/25, or 4%). There were no instances of reoperation for bleeding, perioperative myocardial infarction, renal failure, pulmonary failure, intraaortic balloon pump use, or sternotomy infection in these patients. Eleven patients (44%) were hospitalized for fewer than 10 days after operation, and all but two (23/25, or 92%) were discharged within 20 days after operation. All patients were followed up, and survival and New York Heart Association functional class were determined. Cumulative survival rate was 94% at 1 year and 88% at 5 years. The cumulative percent survival rate with class I or II function was 92% at 1 year and 80% at 5 years. No patient had recurrent angina.

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Previous studies have related preoperative status and severity of disease to the outcome of coronary artery bypass surgery. Although increased perfusion and clamp times increase the risk of cardiac surgical procedures, the importance of these factors in relation to the patient's preoperative condition and the severity of disease has not previously been determined. In this study of 1078 patients, we examined the correlation between the patient's preoperative condition, the severity of coronary disease, and duration of perfusion and clamp time, and the type of oxygenator used with the mortality and morbidity associated with coronary artery bypass grafting. One-way analysis of variance and multiple correlation analysis showed that perfusion time, clamp time and nonclamp perfusion time correlated with mortality, perioperative infarction, the use of intra-aortic balloon pump, stroke, renal failure, pulmonary failure, infection, and leg wound complications (p less than 0.05). Perfusion time, clamp time and nonclamp perfusion time did not correlate with postoperative bleeding or sternal wound complications. Nonclamp perfusion time correlated more strongly than any other factor with mortality, perioperative infarction, the use of intra-aortic balloon pump, renal failure, pulmonary failure and infection (p less than 0.05). Clamp time correlated more than any other factor with the development of leg-wound complications (p less than 0.05). The use of a bubble rather than a membrane oxygenator was significantly related to mortality, stroke, infection and leg wound complications by one-way analysis of variance (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

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Much of the research related to cardiopulmonary bypass in recent years has been directed toward defining the changes in plasma and blood cells during bypass. In this review, recent information is reexamined for six areas of current interest. These areas are complement activation, immune response, anaphylactic reactions, coagulation, and cerebral dysfunction. Complement may be activated by either the classical or alternate pathway during cardiopulmonary bypass and protamine administration. Membrane oxygenators appear to diminish the degree of complement activation. Complement is a major factor in the whole body inflammatory response; which often accompanies cardiopulmonary bypass. A product of complement activation, C5a- desArg, causes activation and aggregation of granulocytes. Other products of complement activation lead to lysis of blood cells including granulocytes and red cells. Bubble oxygenators appear to have a distinct disadvantage compared to membrane oxygenators regarding infection. Airborne microorganisms are more likely to be entrained into circulating blood with bubble oxygenators than with membrane oxygenators. Bubble oxygenators cause a greater decrease in leukocyte number and function than membrane oxygenators. Anaphylactic reactions have been associated with use of antibiotics, blood products, protamine, and volume expanders during cardiopulmonary bypass. Protamine reactions may be on an immunological basis or due to direct toxicity of the drug. Free radicals including superoxide, hydrogen peroxide, and the hydroxyl radical may be generated during cardiopulmonary bypass and reperfusion. Free radical scavengers including; vitamin E, coenzyme Q, vitamin C, mannitol, and glutathione have been studied. The avoidance of blood transfusion because of risk of transmitted infection including AIDS has become a major goal in cardiac surgery. Factors that correlate with increased transfusion requirement include low hematocrit, female gender, increased age, small body size, low ejection fraction, reoperation, and emergency operation. Heparin resistance due to antithrombin III deficiency is being recognized more commonly. Antithrombin III deficiency may be corrected with fresh frozen plasma. Patients with heparin induced thrombocytopenia may be difficult to manage. Several management protocols are suggested. The most straightforward appears to be the use of aspirin preoperatively and platelet transfusions postoperatively. The incidence of cerebral dysfunction after cardiopulmonary bypass depends on the sensitivity of the test or indicator used. Perioperative stroke is associated with intrinsic cerebrovascular disease and atherosclerosis of the ascending aorta. Retinal angiograms during cardiopulmonary bypass show that microemboli are very common. Cerebroplegia has been shown to extend the period of safe circulatory arrest in animals. Much of the new knowledge concerning cardiopulmonary bypass is the result of close collaboration between cardiac surgeons and nonsurgical scientists.

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