Modulus of Elasticity of Two Ceramic Materials and Stress-Inducing Mechanical Deformation following Fabrication Techniques and Adhesive Cementation Procedures of a Dental Ceramic.

STATEMENT OF PROBLEM: Fabrication technique, precementation, and cementation operative procedures can induce significant modification of the stressing patterns throughout the thickness of some classes of dental ceramic materials. OBJECTIVES: To estimate, by means of the deflection test, residual stress in restorative dental ceramic following fabrication technique, precementation, and resin cement coating procedures and to relate it to the elastic property of the ceramic material tested. MATERIALS AND METHODS: From IPS e.max® Press, lithium disilicate heat-pressed glass-ceramic (elastic modulus of 95 ± 5 GPa) disc-shaped specimens (n = 10) were made according to the manufacturer's instructions. One surface of the specimens was polished to provide accurate baseline profilometric measurements (reference surface). Deflection measurements were performed after polishing and annealing alumina air-particle abrasion of the unpolished surface followed by resin cement coating of the alumina air-particle abraded surface. The specimens were reprofiled at 24, 48, and 168 hrs after coating. The Friedman test followed by Dunn's multiple comparison test was employed to identify significant differences (p < 0.05). To compare the difference in mean of maximum mechanical deflection, after cement coating at 0 hr, between two different ceramic materials (IPS e.max Press and Vitadur Alpha (result from another study)), Student's t-test for unpaired data was performed. RESULTS: Baseline profilometric measurements identified a convex form on the polished surface of the ceramic discs with a mean of maximum mechanical deflection of 4.45 ± 0.87 µm. A significant reduction in convexity of the polished specimens was characterized after alumina air-particle abrasion of the unpolished surface. The mean deflection significantly increased after resin cement coating and did not change over the time investigated. CONCLUSIONS: The precementation treatment, namely, alumina air-particle abrasion and cementation procedure of IPS e.max® Press glass-ceramic disc-shaped specimens generates stress that induced mechanical deformation. However, a dental ceramic material with higher elastic modulus (stiffer) would minimize stress-inducing mechanical deformation.

Prevalence of multidrug-resistant organisms in migrant children admitted to an Italian cardiac surgery department, 2015-2016.

Screening on hospital admission to identify multidrug-resistant organism (MDRO) colonization is a frequently discussed topic. We report the results of microbiological screening in 141 Italian and 354 migrant children candidates for cardiac surgery conducted in 2015-2016. In all, 25% of Italian children and more than 65.4% of African and Romanian children carried at least one MDRO (meticillin-resistant Staphylococcus aureus; extended-spectrum ß-lactamase enzymes; carbapenemase producers; and vancomycin-resistant enterococci). Based on our findings, we propose that non-geographically limited approaches are needed to improve infection prevention and control.

Early or late fresh frozen plasma administration in newborns and small infants undergoing cardiac surgery: the APPEAR randomized trial.

BACKGROUND: In newborns and small infants undergoing cardiac surgery with cardiopulmonary bypass (CPB) and blood priming, it is unclear whether there is reduced blood loss if fresh frozen plasma (FFP) is added to the CPB priming volume. This single-centre, randomized trial tested the hypothesis that the administration of FFP after CPB (late FFP group) is superior to FFP priming (early FFP group) in terms of postoperative bleeding and overall red blood cell (RBC) transfusion. METHODS: Seventy-three infants weighing <10 kg were randomly allocated to receive FFP to supplement RBCs in the CPB priming solution ( n =36) or immediately after CPB ( n =37). The primary endpoint was a difference in postoperative blood loss; secondary endpoints included the amount of RBCs and FFP transfused through the first 48 postoperative hours. RESULTS: All patients were included in the analysis. Patients in the late FFP arm had greater postoperative mean blood loss than patients in the early FFP arm [33.1 ( sd 20.6) vs 24.1 (12.9) ml kg -1 ; P =0.028], but no differences in transfusions were found. The subgroup of cyanotic heart disease patients had comparable results, but with greater use of RBCs in the late FFP group. CONCLUSIONS: In infants undergoing cardiac surgery, FFP in the priming solution appears slightly superior to late administration in terms of postoperative bleeding. CLINICAL TRIAL REGISTRATION: www.ClinicalTrials.gov , NCT02738190.

Microcirculatory changes in children undergoing cardiac surgery: a prospective observational study.

BACKGROUND: The effects of cardiac surgery on the microcirculation of children are unknown. The aim of this study was to assess the microcirculatory changes in children undergoing surgery for correction of congenital heart disease. METHODS: We used a videomicroscope (Sidestream Dark Field, SDF) in a convenience sample of 24 children

Desmopressin after cardiac surgery in bleeding patients. A multicenter randomized trial.

BACKGROUND: Previous studies showed that desmopressin decreases post-operative blood loss in patients undergoing cardiac surgery. These studies were small and never studied the effect of desmopressin in patients with active bleeding. Objective of the study was to determine whether desmopressin reduces red blood cells transfusion requirements in patients with active bleeding after cardiac surgery who had been pre-treated with tranexamic acid. METHODS: This multicenter, randomized, double-blind, placebo-controlled, parallel-group study randomized elective patients with bleeding after cardiac surgery despite pre-treatment with tranexamic acid, to receive placebo (saline solution) or a single administration of desmopressin (0.3 µg/kg in saline solution). The primary endpoint was the number of patients requiring red blood cells transfusion after randomization and during hospital stay. Secondary end points were: blood loss from chest tubes during the first 24 h after study drug administration, hours of mechanical ventilation, intensive care unit stay, and in-hospital mortality. RESULTS: The study was interrupted after inclusion of 67% of the planned patients for futility. The number of patients requiring red blood cells transfusion after randomization was 37/68 (54%) in desmopressin group and 33/67 (49%) in placebo group (P = 0.34) with no difference in blood loss: 575 (interquartile 422-770) ml in desmopressin group and 590 (476-1013) ml in placebo group (P = 0.42), mechanical ventilation, intensive care unit stay or mortality. CONCLUSIONS: This multicenter randomized trial demonstrated that, in patients pre-treated with tranexamic acid, desmopressin should not be expected to improve treatment of patients who experience bleeding after cardiac surgery.

A prospective pilot study of platelet function and its relationship with postoperative bleeding in pediatric cardiac surgery.

BACKGROUND: Postoperative bleeding is a major problem in pediatric cardiac surgery with cardiopulmonary bypass (CPB). It recognizes a multifactorial cause, inclusive of coagulation factors consumption, hyperfibrinolysis, incomplete heparin reversal, and platelet consumption. Limited information on platelet function is available. This pilot study investigates platelet function changes in pediatric cardiac operations and their relationship with postoperative bleeding. METHODS: A cohort of 22 patients aged four years or less were prospectively analyzed. Besides the usual coagulation tests, they were studied for platelet function at four points in time: preoperative, arrival in the intensive care unit, first and second postoperative day. Platelet function was measured with multiple electrode aggregometry TRAP-test. RESULTS: After the cardiac operation there was a non-significant decrease in platelet function, with 36% of the patients demonstrating increased aggregability. Platelet count demonstrated a significant (P=0.001) decrease related to the CPB duration. The International Normalized Ratio (INR) was significantly (P=0.001) increased after the operation. Postoperative bleeding was associated with the degree of thrombocytopenia (P=0.014), the increase in INR (P=0.001), and the prolongation of the activated partial thromboplastin time (P=0.002). CONCLUSION: In this pilot study, platelet function in pediatric patients undergoing cardiac surgery demonstrates a variable pattern and no association with postoperative bleeding. Confounding factors like age and cyanosis should be addressed with larger patient populations.

Transient and residual stresses in a pressable glass-ceramic before and after resin-cement coating determined using profilometry.

OBJECTIVE: The effect of heat-pressing and subsequent pre-cementation (acid-etching) and resin-cementation operative techniques on the development of transient and residual stresses in different thicknesses of a lithium disilicate glass-ceramic were characterised using profilometry prior to biaxial flexure strength (BFS) determination. METHODS: 60 IPS e.max Press discs were pressed and divested under controlled conditions. The discs were polished on one surface to thicknesses of 0.61±0.05, 0.84±0.08, and 1.06±0.07 mm (Groups A-C, respectively). The mean of the maximum deflection (acid-etching and resin-coating was determined using high resolution profilometery prior to BFS testing. Paired sample t-tests were performed (p<0.05) on the 20 individual samples in each group (Groups A-C) for each comparison. Differences between the baseline quantification and resin-cement coating deflection values and BFS values for Groups A-C were determined using a one-way ANOVA with post hoc Tukey tests (p<0.05). RESULTS: Baseline quantification for Groups A-C identified no significant differences between the group means of the maximum deflection values (p=0.341). Following HF acid-etching, a significant increase in deflection for all groups (p<0.001) was identified compared with the baseline quantification. Additionally, resin-cement coating significantly increased deflection for Group A (p<0.001), Group B (p<0.001) and Group C (p=0.001) specimens for the individual groups. The increased deflection from baseline quantification to resin-cement coating was significantly different (p<0.001) for the three specimen thicknesses, although the BFS values were not. SIGNIFICANCE: The lower reported baseline quantification range of the mean of the maximum deflection for the IPS e.max(®) Press specimens was predominantly the result of specimen polishing regime inducing a tensile stress state across the surface defect integral which accounted for the observed surface convexity. Acid-etching and resin-cementation had a significant impact on the development and magnitude of the transient and residual stresses in the lithium disilicate glass-ceramic investigated.

Transient and residual stresses induced during the sintering of two dentin ceramics.

OBJECTIVES: To characterize the stress induced deformation of bi-axial flexure strength (BFS) test specimens during processing to provide an insight into sintering effects and associated BFS determination. METHODS: 40 Vitadur-Alpha and 80 IPS e.max Ceram disc-shaped specimens were condensed and a sintered on a silicon nitride refractory tray under controlled firing and cooling parameters. The mean of the maximum deflection (µm) and Ra values (µm) were determined using a high resolution profilometer and were related to the orientation of the measured surface within the furnace. BFS testing of the subsequent groups (n = 20) was performed and the data related to the measured deformation of the sintered specimens. A two-way analysis of variance (ANOVA) where factors were identified as surface state and firing orientation with post hoc Tukey's tests was complemented by pair-wise comparisons with a Student's t-test for each measurement (P < 0.05). RESULTS: The mean of the maximum deflection values and the mean BFS for Vitadur Alpha discs were not significantly influenced by firing orientation (P = 0.248 and P = 0.284, respectively). However, the Ra values were significantly different (P < 0.001). The two-way ANOVA revealed a significant impact on the mean of the maximum deflection measurements for surface state (P < 0.001) and firing orientation (P < 0.001) during sintering (P < 0.001). The mean Ra values were not significantly influenced. The BFS of sintered IPS e.max Ceram discs was sensitive to firing orientation (P < 0.001). SIGNIFICANCE: Conventional glass theory explains that residual thermal stress gradients induced during sintering can cause test specimen deformation which can alter the expected BFS data. The study demonstrates that variability such as firing orientation during sintering which is very rarely reported in the literature can have a significant impact on the reported BFS data and can confound its interpretation.

The deformation and strength of a dental ceramic following resin-cement coating.

OBJECTIVES: The hypothesis tested was that processing, pre-cementation and cementation techniques can modify the profilometrically measured deformation of a ceramic. METHODS: Three-point flexural moduli of a resin-cement were characterised following light irradiation at 430 and 180 mW cm⁻². Thirty IPS e.max Ceram discs were prepared and a reference surface produced by polishing. Discs were annealed, alumina particle air abraded and resin-coated. Profilometric evaluation was performed following each pre-cementation or cementation operative technique using a contact diamond stylus profilometer. Bi-axial flexure strength of the resin-coated discs, light irradiated at 430 and 180 mW cm⁻² (Groups A and B), and the un-coated discs (Group C) was determined. Data were analysed by a one-way analysis of variance with post hoc Tukey tests (P<0.05), or repeat measure analyses when appropriate. RESULTS: Annealing (at 510°C for 40 min) resulted in a significant reduction (P<0.001) in the characterised mean deflection, as did alumina particle air-abrasion (P<0.001). Resin-cement coating significantly increased the mean deflection for Groups A and B (P<0.001) specimens against the uncoated state. Furthermore no significant impact of increasing time or irradiation intensity on the mean deflection was identified. The mean bi-axial flexure strength was significantly increased (P<0.001) after resin-coating (Groups A and B) when compared with Group C specimens although no difference between Groups A and B specimens (P=0.291) was identified. CONCLUSION: The results of the profilometric technique in combination with the strength supported a strengthening mechanism sensitive to shrinkage stress generation associated with the polymerisation of resin-cements.

Deformation of a dental ceramic following adhesive cementation.

Stress-induced changes imparted in a 'dentin-bonded-crown' material during sintering, annealing, pre-cementation surface modification, and resin coating have been visualized by profilometry. The hypothesis tested was that operative techniques modify the stressing pattern throughout the material thickness. We polished the upper surfaces of 10 ceramic discs to remove surface imperfections before using a contact profilometer (40-nm resolution) to measure the 'flatness'. Discs were re-profiled after annealing and after alumina particle air-abrasion and resin-coating of the 'fit' surface. Polished surfaces were convex, with a mean deflection of 8.4 + or - 1.5 microm. Mean deflection was significantly reduced (P = 0.029) following alumina particle air-abrasion and increased (P < 0.001) on resin-coating. Polishing induced a tensile stress state, resulting in surface convexity. Alumina particle air-abrasion reduced the relative tensile stress state of the contralateral polished surface. Resin-polymerization generated compression within the resin-ceramic 'hybrid layer' and tension in the polished surface and is likely to contribute to the strengthening of ceramics by resin-based cements.

Hypothermic cardiopulmonary bypass as a determinant of late thrombocytopenia following cardiac operations in pediatric patients.

BACKGROUND: Thrombocytopenia after cardiac operations is a common event in both adult and pediatric patients. Late thrombocytopenia (LTCP) is a less common event that is still without a well-recognized cause. This study explores the role of heparin-induced thrombocytopenia (HIT) and other factors (complexity of the operation, temperature management, and drug use) in determining LTCP. METHODS: We conducted an observational study of 63 consecutive patients aged <36 months operated with or without cardiopulmonary bypass (CPB). LTCP was defined as a platelet count <100,000 cells/microl or <50% of the pre-operative count at any point in time between post-operative days 5 and 10. A diagnostic test for heparin-platelet factor 4 (PF4) antibodies was performed in patients with LTCP. Other pre- and post-operative factors were investigated for their association with LTCP. RESULTS: LTCP occurred in 15 (24%) patients. No patient had positive heparin-PF4 antibodies. The lowest temperature on CPB was an independent predictor of LTCP, with a cut-off value at 29 degrees C (sensitivity 80%, specificity 70%). Other factors associated with LTCP were prolonged post-operative use of unfractionated heparin and milrinone. LTCP was associated with increased post-operative morbidity. CONCLUSION: LTCP was related to a combination of factors (operation severity, degree of hypothermia during CPB, prolonged use of unfractionated heparin, and milrinone). The individual contribution of each factor seems difficult to establish. However, the degree of hypothermia during CPB and drug-associated effects were identified. HIT could be excluded in all cases.

Living without aprotinin: the results of a 5-year blood saving program in cardiac surgery.

BACKGROUND: After 20 years of regular use in cardiac surgery patients, aprotinin has recently been withdrawn from the market due to many concerns about its safety. For a number of reasons aprotinin has not been available in Italy since 1998. The present study presents an aprotinin-free treatment protocol applied at our institution during the last 5 years, and aims to verify the results of this protocol in terms of allogeneic blood product transfusions, postoperative blood loss and surgical re-exploration rate. METHODS: Retrospective study on 7988 consecutive patients who underwent cardiac surgery during the years 2003-2007. All the patients received specific hemostasis/coagulation management based on (a) routine use of tranexamic acid, (b) heparin dose-response monitoring, thromboelastography, platelet (PLT) function analysis in a select population of patients, and (c) use of fresh frozen plasma (FFP), PLTs, and desmopressin according to the hemostasis/coagulation profile. Data retrieved from the institutional database were quantity of packed red cells (PRCs), FFP, PLT transfusion rate, blood loss in the first 12 postoperative hours, and surgical re-exploration rate. RESULTS: PRCs were transfused in 40.4% of patients (with higher rates for selected high-risk subpopulations), FFP in 12.9% and PLTs in 2.6%. Surgical re-exploration rate was 3.7%. With respect to historical controls, a significant reduction of PRCs and FFP transfusions was obtained using closed circuits, point of care coagulation tests, and combination of the two. CONCLUSION: This aprotinin-free blood saving program is an effective strategy for allogeneic blood products transfusion containment.

Is there a downgrading in the alert about the hepatitis B virus infection in Italy?

BACKGROUND AND AIM: There is suspicion of a decrease in warning regarding the hepatitis B virus as a health problem both by the infected individuals and their doctors. The aim of this study was to investigate whether the clinical/virology investigation of chronic hepatitis B virus infected individuals is at present accurate. METHODS: The chronic hepatitis B virus surface antigen carriers consecutively attending 13 different hospital divisions in Calabria from July to December 2005 were evaluated to investigate the available information on the grade of their liver disease, their virologic profile and the hepatitis B virus status of their family members. RESULTS: Four-hundred-thirty hepatitis B virus surface antigen positive individuals were enrolled, 417 of whom were Calabrians. Most of them had a diagnosis of chronic liver disease, but a liver biopsy had been performed only in 13.5% of the cases, whereas more than 1/3 of them had not been tested for hepatitis Delta virus co-infection. The majority of these individuals were unaware of the hepatitis B virus status of their family members. Moreover, anti-hepatitis B virus vaccination procedures were not performed in most of the hepatitis B virus surface antigen carrier families. CONCLUSIONS: This study revealed that fundamental clinical, virological, and epidemiological aspects of chronic hepatitis B virus infection are not investigated in many hepatitis B virus surface antigen carriers, suggesting that the general knowledge as regards hepatitis B virus is mostly inadequate.

Reduced systemic heparin dose with phosphorylcholine coated closed circuit in coronary operations.

In this prospective cohort study we addressed the clinical impact of a reduced anticoagulation protocol on the hospital outcome of patients undergoing coronary revascularization with cardiopulmonary bypass. 364 consecutive low to moderate risk patients scheduled for elective isolated coronary operations were admitted to the study. 184 patients (Control Group) received conventional open circuits and full systemic anticoagulation (target activated clotting time 480 seconds); 180 patients (Intraoperative ECMO group) received closed, phosphorylcholine coated circuits and a reduced systemic heparin dose (target activated clotting time 320 seconds). Patients of the Intraoperative ECMO group had less requirement for allogeneic blood products (odds ratio 0.55, 95% confidence interval 0.34-0.92, p = 0.02), a significant containment of blood loss (374 +/- 278 mL vs. 463 +/- 321 mL in Control group, p = 0.005) a lower postoperative peak serum creatinine levels (1.19 +/- 0.48 mg/dL vs. 1.41 +/- 0.94 mg/dL in Control group, p = 0.048), and a significant lower rate of severe morbidity (odds ratio 0.27, 95% confidence interval 0.09-0.81, p = 0.02). A reduction of systemic anticoagulation is feasible with a non-heparin-bonded, closed biocompatible circuit, and results in a significant improvement of the outcome of low to moderate risk coronary patients.

Closed, phosphorylcholine-coated circuit and reduction of systemic heparinization for cardiopulmonary bypass: the intraoperative ECMO concept.

Cardiopulmonary bypass with heparin-bonded circuits reduces systemic heparinization which is associated to a better clinical outcome in cardiac operations. In the present study, a novel biocompatible treatment, based on a phosphorylcholine coating without heparin, has been used to reduce systemic heparinization during cardiopulmonary bypass. Sixty patients underwent coronary revascularization with a fully phosphorylcholine-coated circuit. The circuit was entirely closed; suctions from the field were separated during the cardiopulmonary bypass time. A low systemic heparinization protocol based on half the loading dose of heparin (150 IU/kg) and a target activated clotting time of 320 seconds was applied. No thrombus formation inside the extracorporeal circulation circuit occurred; in-hospital mortality was absent. One patient (1.6%) had a postoperative myocardial infarction and 2 (3.3%) were surgically revised due to bleeding. Homologous blood transfusion rate was 11.6%, postoperative bleeding was 310 +/- 136 ml. If compared to patients treated with heparin-coated circuits and low systemic heparinization, these patients have better platelet count preservation and lower postoperative bleeding. The low thrombogenicity of phosphorylcholine-treated surfaces, despite the absence of surface-immobilized heparin, allows a safe reduction of systemic heparinization in the setting of an ECMO-like intraoperative cardiopulmonary - bypass. This intraoperative ECMO approach offers promising results in terms of clinical outcome after coronary revascularization operations.

Risk factors for fatal myocardial infarction after coronary bypass graft surgery.

BACKGROUND AND OBJECTIVE: The incidence and clinical impact of perioperative myocardial infarction during coronary artery bypass graft surgery vary greatly depending upon the diagnostic criteria applied. Fatal perioperative myocardial infarction has a less arguable diagnosis and clinical impact. The aim of this paper is to find out the risk factors for fatal myocardial infarction after coronary surgery. METHODS: Data from 1561 consecutive patients, who underwent coronary revascularization during a 10-month period, have been retrospectively analysed. After an univariate analysis for pre- and intraoperative risk factors, a multivariate model (logistic regression analysis) was settled. RESULTS: Preoperative use of subcutaneous/intravenous heparin, a heparin sensitivity index < 1.3 and need for a thromboendarterectomy of the left anterior descending coronary artery are independent risk factors for fatal myocardial infarction. The relative risk for fatal myocardial infarction was about 2 in the case of preoperative heparin use or heparin sensitivity index < 1.3 and 5.5 in the case of thromboendarterectomy of the left anterior descending coronary artery. CONCLUSIONS: In patients undergoing coronary artery bypass surgery, preoperative anticoagulation management with heparin may represent a risk factor for fatal myocardial infarction. Patterns of heparin resistance, whether or not due to heparin pretreatment, seem to be closely related to fatal myocardial infarction.

Trillium biopassive surface: a new biocompatible treatment for extracorporeal circulation circuits.

139 patients undergoing cardiac surgery were included in a prospective, randomized trial. Patients were randomly allocated to receive cardiopulmonary bypass (CPB) with Trillium Biopassive Surface (TBS Group) coated oxygenators or conventional circuits (control group). 112 patients were studied with respect to postoperative biochemical profile; a subgroup of 27 patients was studied with respect to perioperative complement (C3a) activation. Patients in the TBS group demonstrated a significantly lower white blood cell count at the end of the operation (p=0.036) and a significantly higher platelet count the day after the operation (p=0.023) when compared to the control group. C3a was significantly higher (p=0.02) in the TBS group after 30 minutes of CPB, but the C3a increase after protamine administration was significantly less pronounced in the TBS group vs. the control group. Further studies involving platelet and leukocyte activation are required to better elucidate the action of this new coating in the setting of routine CPB.

Predictors for heparin resistance in patients undergoing coronary artery bypass grafting.

Heparin resistance (HR) is a common event in cardiac operations. At present, no clear recognition of the risk factors for HR has been reached. The aim of this study was to determine a predictive model for HR, based on the preoperative patient's profile. Two hundred consecutive patients scheduled for elective coronary artery bypass operations were enrolled in a prospective trial. Demographics, type of preoperative anticoagulation therapy and preoperative coagulation profile were collected and statistically analysed with respect to the evidence of a HR. Heparin resistance was defined as at least one activated clotting time < 400 s after heparinization and/or the need for purified antithrombin III (AT-III) administration. With a multivariate analysis we could identify five predictors for HR: AT-III < or = 60%; preoperative subcutaneous heparin therapy; intravenous heparin therapy; platelet count > or = 300000 cells/mm3; age > or = 65 years. We conclude that HR is a predictable event. In the presence of all the risk factors, the likelihood of HR is 99%; in the absence of all of them, it is 10%. Predicting HR allows us to apply many possible therapeutic strategies.

Gabexate mesilate and antithrombin III for intraoperative anticoagulation in heparin pretreated patients.

Thirty patients scheduled for elective myocardial revascularization and having undergone preoperative heparin treatment have been admitted to this prospective, randomized study. The aim of the study was to test two different strategies for preserving circulating antithrombin III (AT-III) during cardiopulmonary bypass. Patients in the control group (group C, n = 10) were treated with a standard heparinization (300 IU/kg). Patients in group A (n = 10) received the same management plus two doses of purified antithrombin III (1000 IU each). Patients in group GA received 200 IU/kg heparin and a continuous infusion of heparin (100 IU/kg/h) and gabexate mesilate (2 mg/kg/h) plus the same dose of antithrombin III as group A. Both group A and group GA demonstrated a preservation of circulating AT-III when compared to group C; this effect was more pronounced in group GA. The total heparin dosage was less in group GA than in groups A and C. Purified AT-III administration is recommended in heparin pretreated patients; the addition of gabexate mesilate to this protocol decreases the heparin requirement and increases the AT-III preservation.

Diabetes and complications after cardiac surgery: comparison with a non-diabetic population.

Diabetes is a well-recognized independent risk factor for mortality due to coronary artery disease. When diabetic patients need cardiac surgery, either coronary-aortic by-pass (CABP) or valve operations (VO), the presence of diabetes represents an additional risk factor for these major surgical procedures. Because of controversial data on mortality rates and post-operative complications in diabetic patients, probably due to not exactly comparable groups of patients, this retrospective study aimed to compare two homogeneous populations, which were different only for the presence or absence of diabetes. We studied 700 patients undergoing cardiac surgery: 350 with and 350 without diabetes, mean age 62 +/- 9 years (67% males); 441 underwent CABP and 259 VO. Apart from the diabetes, the two groups were strictly matched for age, body mass index, concomitant pathologies and smoking habits, except for previous neurological injuries (more frequent in diabetic patients), and for a slightly lower ejection fraction in the diabetic group. Intra- and post-operative complications or events were evaluated carefully: death, number staying in post-operative intensive care unit (ICU), renal, hepatic and respiratory complications, necessity for reoperation and hemotransfusions. Anesthesia and surgical procedures (including extra-corporeal circulation techniques) remained substantially unchanged over the period of recruitment of patients (1996-1998) and applied equally to both groups of patients. All diabetic patients were treated with insulin by using standard procedures in order to optimize metabolic control. Diabetic patients in our study, did not show higher rates of mortality in comparison with non-diabetic patients, but had more total neurological complications, more renal complications, a higher re-opening rate, more prolonged ICU stay, and they needed more blood transfusions. Diabetes remains an independent risk factor for these events even in a multivariate logistic regression model analysis. In the subgroup of diabetic patients who underwent CABP a higher rate of renal dysfunction, re-opening, need for hemotransfusions and prolonged ICU stay were confirmed. In the subgroup of diabetic patients undergoing VO we found a higher rate of renal dysfunction, reopening, prolonged ICU stay and major lung complications. In conclusion, diabetes does not seem to increase the mortality rates of cardiac surgery, but diabetic patients undergoing CABP have, on the basis of the relative risk evaluation, a 5-fold risk for renal complications, a 3.5-fold risk for neurological dysfunction, a double risk of being hemotransfused, reoperated or being kept 3 or more days in the ICU in comparison with non-diabetic patients. Moreover, diabetic patients undergoing VO have a 5-fold risk of being affected by major lung complications.