Intraoperative physiologic variables and outcome in cardiac surgery: Part I. In-hospital mortality.

BACKGROUND: Risk stratification schemes have been developed to predict outcome of coronary artery bypass grafting (CABG) procedures, which are predominately based upon unalterable preoperative patient characteristics. The purpose of this study was to determine if minimum intraoperative hematocrit, maximum glucose concentration, mean arterial pressure on cardiopulmonary bypass, or duration of bypass influence risk-adjusted in-hospital mortality after CABG. METHODS: Outcome data from 2,862 CABG patients were merged with intraoperative physiologic data. A preoperative mortality risk index was calculated for each patient. Variables found significant (p<0.05) by univariate logistic regression were tested in a multiple variable model to determine risk-adjusted association with mortality. RESULTS: Overall mortality rate was 1.85%. The preoperative risk index was significantly associated with mortality (p = 0.0001). No significant association was present between mortality and intraoperative variables. Preexisting hypertension was an independent predictor of mortality after controlling for risk index and bypass duration. CONCLUSIONS: Preexisting hypertension proved to be an independent predictor of mortality in our patient population. This study found no evidence to support the hypothesis that mean arterial pressure less than 50 mm Hg, lower hematocrit, or elevated glucose while on bypass increases in-hospital mortality.

Intraoperative physiologic variables and outcome in cardiac surgery: Part II. Neurologic outcome.

BACKGROUND: The impact of alterable physiologic variables on neurologic outcome after coronary artery bypass grafting procedures is unknown. The purpose of this study was to determine whether minimum intraoperative hematocrit, maximum glucose concentration, or mean arterial pressure during cardiopulmonary bypass influences risk-adjusted neurologic outcome after coronary artery bypass grafting. METHODS: Outcome data from 2,862 patients undergoing coronary artery bypass grafting were merged with intraoperative physiologic data. A preoperative stroke risk index was calculated for each patient. Variables found significant by univariate logistic regression were tested in a multivariable model to determine association with outcome. RESULTS: The incidence of stroke or coma in the study population was 1.3%. After controlling for stroke risk and bypass time, only an index of low mean arterial pressure during bypass retained a significant inverse association with outcome (p = 0.0304). CONCLUSIONS: This study found no evidence that glucose concentration or minimum hematocrit are associated with major adverse neurologic outcome. The association between lower pressure during bypass and decreased incidence of stroke or coma persisted in all risk groups. This points to mechanisms other than hypoperfusion as the primary cause of neurologic injury associated with cardiac surgery.

Patient- and procedure-specific risk factors for postoperative complications in peripheral vascular surgery.

BACKGROUND: Interest in measuring the quality of surgical care has grown over the past decades. As complications after vascular surgery may be used as a quality indicator of care, analysis of these adverse events remains essential. OBJECTIVE: The goal of this study was to identify patient and procedure specific risk factors of postoperative complications following infrainguinal vascular surgery and to describe the incidence, cause and consequence of all complications in this group. PATIENTS AND METHODS: This study included all 296 patients undergoing infrainguinal arterial bypass surgery at our institution over a 5-year period. All complications occurring during these patients' admission were registered in a prospective standardised complication registration and analysed. RESULTS: Seventy-three of 296 (25%) procedures in 247 patients were followed by 129 complications. The mean patient age was 70 years. Factors associated with a significantly higher complication risk were diabetes, critical ischaemia with rest pain or gangrene, a cardiac medical history, acute surgery and a former cerebrovascular accident (CVA). Independent risk factors in multivariate analysis were a former CVA and acute surgery. Postoperative haemorrhage (n = 19), early occlusion of the graft (n = 15) and surgical site infection (n = 10) were the most frequently registered surgery-related complications. The most common consequence of a complication was blood transfusion or treatment with additional medication (33%). In 16% of all complications, a reoperation was necessary. Twelve patients died during admission (mortality 5%). CONCLUSION: A former CVA and acute surgery were independent risk factors of postoperative complications. Identifying the cause and consequence of each complication is essential in a complication registration. When using complications as an indicator of quality of care in this population, an adjustment should be made for patient comorbidity and surgical indication.

Contemporary series of morbidity and mortality after lower limb amputation.

OBJECTIVES: This study was performed in order to assess morbidity and mortality associated with major lower extremity amputation according to an extensive complication registration system used in our hospital. METHODS: All consecutive patients who underwent lower limb major extremity amputation were included from January 1996 until December 2002. Complications were prospectively registered according to our standard complication registration system. RESULTS: In 97 patients 122 amputations were performed including 45 above (AKA) and 77 below (BKA) knee amputations. The conversion rate from below to above knee amputation was 14%. In 65 patients 107 complications occurred (67%). The incidence of wound infection was 10% in the BKA group and 2% in the AKA group. The most frequently reported complications were pressure sores (8%) or originating from the urinary tract (13%). The hospital mortality for BKA was 9% and for AKA 18%. Long-term survival was 62% at 1 year, 50% at 2 years and 29% at 5 years. CONCLUSIONS: An extensive registration system provides us with a detailed insight into the incidence, consequence and cause of complications. Major lower extremity amputations are still associated with considerable morbidity and mortality.

Recording and classification of complications in a surgical practice.

OBJECTIVE: To document the incidence and outcome of complications in the department of surgery. DESIGN: Retrospective study. SETTING: District hospital, The Netherlands. SUBJECTS: 7455 patients operated on between 1 January 1993 and 31 December 1995. MAIN OUTCOME MEASURES: Documentation and outcome of complications (defined as "every unwanted development in the illness of the patient or in the treatment of the patient's illness that occurs in the clinic"). RESULTS: 1078 complications were recorded after 8130 operations (13%), 337 (33%) of which had no long term effects. 175/1078 (16%) required reoperation, and in 134 of these (77%) an error in management or surgical technique was responsible for the complication. 6 patients were irreversibly harmed and of the 141 patients who died, 11 had evidence of some sort of error. CONCLUSIONS: Audit of complications is necessary to improve practice in a surgical department, and weekly morbidity and mortality meetings are a good opportunity for learning about them.

Evaluation of a new transcardiac conductance method for continuous on-line measurement of left ventricular volume.

OBJECTIVE: To evaluate a new, less invasive, conductance method to measure continuous on-line left ventricular volume. End-systolic and end-diastolic volumes obtained with this transcardiac conductance method were compared with simultaneous measurements using the conventional intracardiac conductance catheter. DESIGN: Controlled animal study. SETTING: Research laboratory in a university hospital. SUBJECTS: Six sheep. INTERVENTIONS: Anesthetized sheep were instrumented and inotropic condition was varied by beta-receptor stimulation (5 microg/kg/min of dobutamine) and beta-receptor blockade (1 mg/kg of propranolol). In each condition (control, dobutamine, repeat control, propranolol), ventricular volume was varied over a wide range by gradual preload reduction using a vena caval balloon catheter. MEASUREMENTS AND MAIN RESULTS: We compared the two methods by performing linear regression analysis on simultaneous end-systolic and end-diastolic volumes obtained during gradual caval occlusions. We statistically analyzed the intercepts, slopes, and correlation coefficients of the regression equations relating the transcardiac and conductance catheter measurements to determine the effects of interanimal variability, inotropic condition, and cardiac phase on the relationship between the two methods. The results show an excellent linear correlation between the two methods (mean intercept, -1.82+/-1.24 mL; mean slope, 0.787+/-0.024 and r2 = .94). Both slope and intercept of the relationship between the two methods show a significant interanimal and cardiac phase related variability but no significant dependence on inotropic condition. CONCLUSIONS: The significant interanimal variability indicates that the new method requires individual calibration in each subject. However, the small variability of the regression coefficients with changes in condition indicates that after initial calibration, end-systolic and end-diastolic volume can be followed accurately even in the presence of large changes in volume and inotropic state. This new method may facilitate quantitative continuous assessment of cardiac function in clinical practice, for example, in the intensive care unit.

Survival of proximal third gastric carcinoma.

BACKGROUND AND OBJECTIVES: Proximal third gastric carcinoma is a distinct clinical entity compared with tumors located in other parts of the stomach with a rapid increasing incidence and a poor prognosis. This study was done to evaluate therapy for, and survival of, patients with gastric cardia carcinoma. METHODS: Clinical features and prognosis of 49 patients with proximal third gastric carcinoma between 1985 and 1995 (mean age 69.7 years) were evaluated. RESULTS: In 20 of the 49 patients, laparotomy was excluded because of widespread disease and/or poor clinical condition at presentation. Palliative therapy consisted of gastric tube implantation (n = 4), dilation (n = 3), or radiotherapy (n = 4). In 9 patients, no specific palliative therapy was indicated. Twenty-nine patients underwent laparotomy (59%). In 13 patients, a total gastrectomy with esophagojejunostomy was performed, and in 7 patients a partial gastrectomy was performed. In 9 cases, the tumor was irresectable. In 8 of these 9 patients, a Celestin tube was implanted. Median survival in all patients was 7 months and the expected probability of survival after 50 months was zero. The median survival of patients who underwent a resection was significantly better than in those in whom no resection was performed (23 vs. 4 months, P = 0.047). CONCLUSIONS: We conclude that long-term survival of patients with proximal third gastric carcinoma is poor. However, long-term survival may be best warranted when patients present at an early stage and resection can be performed.

Transesophageal echocardiography in quantification of emboli during femoral nailing: reamed versus unreamed techniques.

We quantified the embolic load to the lungs created with two different techniques of femoral nailing. Eleven patients with 12 traumatic femur fractures were randomized to reamed (7 fractures) and unreamed (5 fractures) groups. Intramedullary nailing was with the AO/ASIF* universal reamed or unreamed nail. Transesophageal echocardiography (TEE) was used to evaluate the quantity and quality of emboli generated by nailing. Data were analyzed using software that digitized the TEE images and quantified the area of embolic particles in each frame. The duration of each level of embolic phenomena (zero, moderate, severe) was used to determine total embolic load with various steps (fracture manipulation, proximal portal opening, reaming, and nail passage). Manual grading of emboli correlated highly with software quantification. Our data confirm the presence and similarity of emboli generation with both methods of intramedullary nailing. Unreamed nails do not protect the patient from pulmonary embolization of marrow contents.