Risto Pokela

Risk Features for Surgical-Site Infections in Coronary Artery Bypass Surgery

OBJECTIVE To identify preoperative and perioperative features that may lead to a risk of surgical-site infection (SSI) after coronary artery bypass surgery. DESIGN 884 patients who underwent coronary artery bypass grafting in 1992 and 1993 were studied. The associations between 23 preoperative and perioperative features and the presence of SSI at the donor site or in the chest area were evaluated by univariate analysis followed by multivariate logistic regression analysis. SETTING A university hospital. RESULTS 172 patients (19.5%) either had an SSI recorded before discharge or had received antibiotics prescribed for a suspected SSI during the 1-month surveillance period after discharge. Multivariate logistic regression analysis showed an extreme body mass index (BMI; P=.015), female gender (P=.023), and chronic obstructive pulmonary disease (COPD; P=.030) to be independent risk features for SSI. The donor site was infected in 136 patients (15.4%), an event for which female gender (P=.003) was the only independent risk feature. Forty-seven patients (5.3%) had an SSI of the chest area, with diabetes (P=.003) and extreme BMI (P=.010) as independent risk features. CONCLUSION Extreme BMI, female gender, and COPD are highly significant independent predictors of the development of SSI. Female gender is a risk feature specifically for SSI at the donor site, whereas diabetes and extreme BMI predict it in the chest area.

Magnesium substitution in elective coronary artery surgery: A double-blind clinical study

Magnesium may be beneficial in the control of ventricular ectopy and supraventricular tachyarrhythmias after coronary artery bypass graft (CABG) surgery, but it is not known whether a high-dose magnesium regimen is superior to a regimen keeping the patient normomagnesemic. A prospective randomized and double-blind clinical comparison was performed in 81 elective CABG patients in order to assess the effects of two different magnesium infusion regimens on electrolyte balance and postoperative arrhythmias. Forty-one patients (high-dose group, H) received 4.2 +/- 0.7 g (mean +/- SD), of magnesium sulfate before cardiopulmonary bypass, followed by an infusion of 11.9 +/- 2.8 g of magnesium chloride until the first postoperative (PO) morning, and a further 5.5 +/- 1.0 g until the second PO morning. Forty patients (low-dose group, L) received magnesium sulfate only after bypass to a total of 2.9 +/- 0.5 g at the first, and 1.4 +/- 0.1 g at the second PO morning. A blood cardioplegia technique was used in both groups, including bolus doses of magnesium chloride to a total of 2.4 +/- 0.6 g and 2.3 +/- 0.6 g to H and L patients, respectively. Continuous Holter tape-recording was used for 12 to 15 hours preoperatively, and for 48 hours postoperatively. Serum magnesium peaked in H patients on the first PO morning at 1.60 +/- 0.25 mmol/L, whereafter it declined to the normal level on the third PO morning. Patients in the L group were normomagnesemic, except after the start of bypass.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of vancomycin and cefuroxime for infection prophylaxis in coronary artery bypass surgery.

OBJECTIVE To investigate clinically significant differences between vancomycin and cefuroxime for perioperative infection prophylaxis in coronary artery bypass surgery. DESIGN A total of 884 patients were randomized prospectively to receive either cefuroxime (444) or vancomycin (440) and were assessed for infectious complications during hospitalization and 1 month postoperatively. SETTING A university hospital. RESULTS The overall immediate surgical-site infection rate was 3.2% in the cefuroxime group and 3.5% in the vancomycin group (difference, -0.3; 95% confidence interval, -2.6-2.1). CONCLUSIONS The data suggest that vancomycin has no clinically significant advantages over cephalosporin in terms of antimicrobial prophylaxis. We suggest that cefuroxime (or first-generation cephalosporins, which were not studied here) is a good choice for infection prophylaxis in connection with coronary artery bypass surgery in institutions without methicillin-resistant Staphylococcus aureus problems. In addition to the increasing vancomycin-resistant enterococci problem, the easier administration and usually lower price of cefuroxime make it preferable to vancomycin.

Preoperative C-reactive protein and outcome after coronary artery bypass surgery

BACKGROUND C-reactive protein (CRP) is a predictor of early and late outcome after coronary angioplasty, but there is scant data on its impact on the outcome after coronary artery bypass grafting (CABG). METHODS The predictive value of preoperative CRP was evaluated in a series of 764 patients who underwent on-pump CABG. RESULTS During the in-hospital stay, 13 patients (1.7%) died, 45 (4.5%) developed low cardiac output syndrome, and 28 (3.7%) suffered minor or major cerebrovascular complications. Patients with a preoperative serum concentration of CRP>/=1.0 mg/dL had a higher risk of overall postoperative death (5.3% vs 1.1%, p = 0.001), cardiac death (4.4% vs 0.8%, p = 0.002), low cardiac output syndrome (8.8% vs 3.7%, p = 0.01), and any cerebrovascular complication (4.4% vs 3.5%, p = 0.66). Preoperative serum concentration of CRP>/=1.0 mg/dL was significantly more frequent among patients with history of myocardial infarction, diabetes, lower limb ischemia, low left ventricular ejection fraction, NYHA class IV, and in those undergoing urgent or emergency operation. At multivariate analysis, preoperative serum concentration of CRP >/= 1.0 mg/dL (p = 0.01, O.R.: 6.97) and left ventricular ejection fraction (p = 0.01, O.R.: 0.95) were independent predictors of postoperative death. Postoperative mortality rate was 0.3% among patients with preoperative CRP < 1.0 mg/dL and an ejection fraction >/=50%, whereas it was 21.4% among those with a preoperative CRP >/= 1.0 mg/dL and an ejection fraction less than 50% (p < 0.0001). CONCLUSIONS Preoperative serum concentration of CRP in patients undergoing on-pump coronary artery bypass surgery is an important determinant of postoperative outcome.

Is single-dose antibiotic prophylaxis sufficient for coronary artery bypass surgery? An analysis of peri-and postoperative serum cefuroxime and vancomycin levels

Preliminary findings have suggested that a single intravenous dose of antibiotic is effective for infection prophylaxis in cardiac surgery. However there are still insufficient data on this proposed regimen. We measured serum cefuroxime and vancomycin levels after three different dosage regimens, in patients undergoing coronary artery bypass grafting (CABG). Sixty patients were randomized into three cefuroxime and three vancomycin groups with 10 patients in each: a group given a one-day course, or an additional dose during cardiopulmonary bypass or a single dose. Serum levels of the antibiotics were measured at various times throughout the operative procedure and until 48 h after the start of prophylaxis. Each of the six dosage regimens maintained serum levels adequate for infection prophylaxis throughout the operative procedure. Serum levels remained above 2 mg/L for more than 8 h postoperatively, even in the single-dose cefuroxime group and above 4 mg/L for more than 24 h with all the vancomycin dosage regimens. Thus a single dose of cefuroxime (3 g or 1.5 g) or vancomycin (1.5 g) seems to achieve and maintain serum levels sufficient for infection prophylaxis several hours after CABG procedures.

Infection Prophylaxis in Pulmonary Surgery: A Randomized Prospective Study

A prospective randomized study to evaluate the efficacy of antibiotic prophylaxis against postoperative infections was carried out on 120 patients undergoing pulmonary operations. The patients were randomized into two groups of 60 patients each. One group received doxycycline (deoxytetracycline) prophylaxis for five days, and the other received cefuroxime (a second-generation cephalosporin) for one day. The groups were comparable with regard to age, sex, common risk factors, diagnosis, and operative procedures. A reduction in the infection rate was noted in the cefuroxime group (10/60) compared with the doxycycline group (19/60), but the difference was not statistically significant (p = 0.055). In major infections (empyema and pneumonia) there was no difference between the groups (4/60 in the cefuroxime group and 5/60 in the doxycycline group), but a significant (p less than 0.05) reduction was noted in minor infections (6/56 and 14/55, respectively) such as lower respiratory tract infections and prolonged fever. There were no wound infections in the two study groups. There were significantly (p less than 0.05) fewer postoperative fever reactions (axillary temperature greater than 37.5 degrees C) in the cefuroxime group (30/60) compared with the doxycycline group (44/60). Both antibiotics were effective in preventing wound infections, but cefuroxime may also be beneficial in preventing minor respiratory infections. The bactericidal effect of cefuroxime may explain this finding.

ABO blood group distribution and severity of coronary artery disease among patients undergoing coronary artery bypass surgery in Northern Finland

During the last few decades, several studies have showed a certain association between ABO blood groups, in particular non-O blood groups, and the risk of developing severe manifestations of atherosclerosis [1–6]. Some studies also showed an association between these blood groups and the development of lower limb venous thrombosis [7–9]. Indeed, increased levels of factor VIII [5,9–12], von Willebrand factor [6,10–12], fragment 1 + 2 of prothrombin [13], and lower APTT ratio [12] have been observed in subjects with non-O blood groups, thus the latter seem to have an increased prothrombotic tendency. Herein, we report a study on the distribution of ABO blood groups in a series of patients who underwent primary coronary artery bypass grafting (CABG) in order to evaluate whether ABO blood groups are associated with an increased risk of developing severe coronary artery disease and with poorer postoperative outcome.

A Retrospective Comparative Study of Aortic Valve Replacement with St. Jude Medical and Medtronic-Hall Prostheses: A 20-year Follow-up Study

Objective - To compare the long-term clinical outcome of patients who underwent aortic valve replacement with St. Jude Medical and Medtronic-Hall mechanical prostheses. Design - From June 1978 to June 1982, 43 Medtronic-Hall and 48 St. Jude Medical mechanical valves were implanted in 90 consecutive patients with aortic valve disease, and their clinical outcome was retrospectively assessed. Results - At 20 years in the St. Jude Medical group and in the Medtronic-Hall group the actuarial rates of overall survival were 50 and 49% ( p = NS), of cardiovascular survival 66 and 63% ( p = NS), of valve-related survival 95 and 91% ( p = NS), of freedom from major valve-related complications 83 and 45% ( p = 0.005), from major cerebrovascular events 93 and 71% ( p = 0.06), from valve thrombosis 97 and 89% ( p = NS), from aortic valve reoperation 93 and 88% ( p = NS), from major bleeding 96 and 82% ( p = 0.04), and from endocarditis 93 and 82% ( p = NS), respectively. The linearized rate of overall major aortic valve prosthesis-related complications was 3.47%/year in the Medtronic-Hall valve group and 1.53%/year in the St. Jude Medical valve group ( p = 0.003). Multivariate analysis showed that the type of prosthesis was predictive of freedom from valve-related complications ( p = 0.01; 2.849; C.I. 95%: 1.246-6.516). Conclusion - The aortic St. Jude Medical mechanical valve seems to be associated with a slightly lower rate of longterm valve-related morbidity than the aortic Medtronic-Hall mechanical valve. Because of the small patient population and the retrospective nature of the study, the choice between these two prostheses should not be made only on the basis of these findings. However, these results suggest a reappraisal for further comparative studies with such an extended follow-up.

Computed tomographic evaluation of retrosternal adhesions after pericardial substitution

BACKGROUND Reoperative median sternotomy can result in cardiac injury and serious bleeding, with the rate ranging from 2% to 6%. Closure of the native pericardium can maintain a preventing plane of cleavage. In patients in whom primary pericardial closure is not possible, several substitutes have been tried with variable results. We conducted a prospective study to evaluate the clinical feasibility of polytetrafluoroethylene and polyglycolic acid patches as pericardial substitutes, using computed tomography for imaging the postoperative state of the retrosternal space. METHODS The basic population comprised 540 patients who were scheduled for coronary artery bypass grafting, and 52 of them who met the research criteria were chosen for computed tomographic evaluation after 5 years after the primary operation. RESULTS As a substitute, polytetrafluoroethylene seemed to be less adhesive to the posterior surface of the sternum. Total adhesion scores were also statistically significant (p < 0.001) to the advantage of polytetrafluoroethylene over polyglycolic acid as a pericardial substitute. CONCLUSIONS Polytetrafluoroethylene membrane seems to be capable of minimizing retrosternal adhesion formation and thus it may protect the heart during subsequent reoperative sternotomy.

Ten-Year Survival after Resection for Lung Carcinoma: Effect of Blood Transfusion and Tumour Stage on Outcome

The objectives were to evaluate the prognosis in resected lung cancer and to observe if perioperative blood transfusion adversely affects the prognosis. Of 208 patients with resection for lung cancer in 1978-1980, all but five were smokers: 127 had squamous cell and 81 non-squamous cell carcinoma. Stage I disease was found in 143 patients. (69%), stage II in 18 (9%) and stage IIIa in 47 (23%). Five-year survival was 52% in stage I, 29% in stage II and 7% in stage IIIa tumour; the respective 10-year rates were 37, 19 and 3%. Patients given perioperative blood transfusion (n = 95) had poorer prognosis than the non-transfused patients. According to Cox multivariate analysis, however, the relative risk of death was only slightly increased by perioperative transfusion (p = 0.07). In patients with stage II or IIIa carcinoma at diagnosis, this relative risk was 2.17 and 4.99 times higher than in stage I (p = 0.004 and p = 0.0001). Long-term survival thus was related to extent of the disease at diagnosis rather than to numbers of blood transfusions.