Transfusion Requirements in Cardiac Surgery III (TRICS III): Study Design of a Randomized Controlled Trial.

OBJECTIVES: To determine if a restrictive transfusion threshold is noninferior to a higher threshold as measured by a composite outcome of mortality and serious morbidity. DESIGN: Transfusion Requirements in Cardiac Surgery (TRICS) III was a multicenter, international, open-label randomized controlled trial of two commonly used transfusion strategies in patients having cardiac surgery using a noninferiority trial design (ClinicalTrials.gov number, NCT02042898). SETTING: Eligible patients were randomized prior to surgery in a 1:1 ratio. PARTICIPANTS: Potential participants were 18 years or older undergoing planned cardiac surgery using cardiopulmonary bypass (CPB) with a preoperative European System for Cardiac Operative Risk Evaluation (EuroSCORE I) of 6 or more. INTERVENTIONS: Five thousand patients; those allocated to a restrictive transfusion group received a red blood cell (RBC) transfusion if the hemoglobin concentration (Hb) was less than 7.5 g/dL intraoperatively and/or postoperatively. Patients allocated to a liberal transfusion strategy received RBC transfusion if the Hb was less than 9.5 g/dL intraoperatively or postoperatively in the intensive care unit or less than 8.5 g/dL on the ward. MEASUREMENTS AND MAIN RESULTS: The primary outcome was a composite of all-cause mortality, myocardial infarction, stroke, or new onset renal dysfunction requiring dialysis at hospital discharge or day 28, whichever comes first. The primary outcome was analyzed as a per-protocol analysis. The trial monitored adherence closely as adherence to the transfusion triggers is important in ensuring that measured outcomes reflect the transfusion strategy. CONCLUSION: By randomizing prior to surgery, the TRICS III trial captured the most acute reduction in hemoglobin during cardiopulmonary bypass.

Does a Platelet Transfusion Independently Affect Bleeding and Adverse Outcomes in Cardiac Surgery?

BACKGROUND: Conflicting results have been reported concerning the effect of platelet transfusion on several outcomes. The aim of this study was to assess the independent effect of a single early intraoperative platelet transfusion on bleeding and adverse outcomes in cardiac surgery patients. METHODS: For this observational study, 23,860 cardiac surgery patients were analyzed. Patients who received one early (shortly after cardiopulmonary bypass while still in the operating room) platelet transfusion, and no other transfusions, were defined as the intervention group. By matching the intervention group 1:3 to patients who received no early transfusion with most comparable propensity scores, the reference group was identified. RESULTS: The intervention group comprised 169 patients and the reference group 507. No difference between the groups was observed concerning reinterventions, thromboembolic complications, infections, organ failure, and mortality. However, patients in the intervention group experienced less blood loss and required vasoactive medication 139 of 169 (82%) versus 370 of 507 (74%; odds ratio, 1.65; 95% CI, 1.05 to 2.58), prolonged mechanical ventilation 92 of 169 (54%) versus 226 of 507 (45%; odds ratio, 1.47; 94% CI, 1.03 to 2.11), prolonged intensive care 95 of 169 (56%) versus 240 of 507 (46%; odds ratio, 1.49; 95% CI, 1.04 to 2.12), erythrocytes 75 of 169 (44%) versus 145 of 507 (34%; odds ratio, 1.55; 95% CI, 1.08 to 2.23), plasma 29 of 169 (17%) versus 23 of 507 (7.3%; odds ratio, 2.63; 95% CI, 1.50-4.63), and platelets 72 of 169 (43%) versus 25 of 507 (4.3%; odds ratio, 16.4; 95% CI, 9.3-28.9) more often compared to the reference group. CONCLUSIONS: In this retrospective analysis, cardiac surgery patients receiving platelet transfusion in the operating room experienced less blood loss and more often required vasoactive medication, prolonged ventilation, prolonged intensive care, and blood products postoperatively. However, early platelet transfusion was not associated with reinterventions, thromboembolic complications, infections, organ failure, or mortality.

Trait anxiety mediates the effect of stress exposure on post-traumatic stress disorder and depression risk in cardiac surgery patients.

BACKGROUND: Post-traumatic stress disorder (PTSD) and depression are common after cardiac surgery. Lifetime stress exposure and personality traits may influence the development of these psychiatric conditions. METHODS: Self-reported rates of PTSD and depression and potential determinants (i.e., trait anxiety and stress exposure) were established 1.5 to 4 years after cardiac surgery. Data was available for 1125 out of 1244 (90.4%) participants. Multivariable linear regressions were conducted to investigate mediating and/or moderating effects of trait anxiety on the relationship between stress exposure, and PTSD and depression. Pre-planned subgroup analyses were performed for both sexes. RESULTS: PTSD and depression symptoms were present in 10.2% and 13.1% of the participants, respectively. Trait anxiety was a full mediator of the association between stress exposure and depression in both the total cohort and female and male subgroups. Moreover, trait anxiety partially mediated the relationship between stress exposure and PTSD in the full cohort and the male subgroup, whereas trait anxiety fully mediated this relationship in female patients. Trait anxiety did not play a moderating role in the total patient sample, nor after stratification on gender. LIMITATIONS: The unequal distribution of male (78%) and female patients (22%) might limit the generalizability of our findings. Furthermore, risk factors were investigated retrospectively and with variable follow-up time. CONCLUSIONS: In cardiac surgery patients, trait anxiety was found to be an important mediator of postoperative PTSD and depression. Prospective research is necessary to verify whether these factors are reliable screening measures of individuals' vulnerability for psychopathology development after cardiac surgery.

Effectiveness of pericardial lavage with or without tranexamic acid in cardiac surgery patients receiving intravenous tranexamic acid: a randomized controlled trial.

OBJECTIVES: Pericardial lavage with saline, with or without tranexamic acid (TA), is still not evidence-based within current clinical practice as a part of a blood conservation strategy in cardiac surgery patients receiving intravenous TA administration. The objective was to determine whether intravenous TA combined with pericardial lavage with saline, with or without TA, reduces blood loss by 25% after cardiac surgery measured in the first 12 h postoperatively. METHODS: In this single-centre, randomized controlled, multiple-armed, parallel study, individual patients were randomly assigned to receive either topical administration of 2 g TA diluted in 200 ml of saline (TA group), 200 ml of saline (placebo group) or no topical administration at all (control group). Eligible participants were all adults aged 18 or older and scheduled for elective cardiac surgery on cardiopulmonary bypass. All patients received 2 g TA intravenously before sternal incision and 2 g TA after cardiopulmonary bypass. The main outcome measure was the 12-h postoperative blood loss. RESULTS: In total, 739 individuals were analysed according to intention-to-treat analyses (TA group, n = 245 patients; placebo group, n = 249 patients; control group, n = 245 patients). There was no difference in the median 12-h postoperative blood loss between the three groups [TA group, 290 (IQR 190-430) ml; placebo group, 290 (IQR 210-440) ml; control group, 300 (IQR 190-450) ml, P= 0.759]. CONCLUSIONS: Pericardial lavage, with or without TA, does not result in a statistically significant difference in the 12-h postoperative blood loss in cardiac surgery patients receiving intravenous TA administration. Pericardial lavage with saline, with or without TA, should not be a part of a blood conservation strategy.

Intraoperative Anemia and Single Red Blood Cell Transfusion During Cardiac Surgery: An Assessment of Postoperative Outcome Including Patients Refusing Blood Transfusion.

OBJECTIVES: Increasing evidence suggests benefits from restrictive red blood cell transfusion (RBC) thresholds in major surgery and critically ill patients. However, these benefits are not obvious in cardiac surgery patients with intraoperative anemia. The authors examined the association between uncorrected hemoglobin (Hb) levels and selected postoperative outcomes as well as the effects of RBCs. DESIGN: Cohort study with prospectively collected data from a cardiac surgery registry. SETTING: A major cardiac surgical hospital within the Netherlands, which is also a referral center for Jehovah's Witnesses. PARTICIPANTS: Patients (23,860) undergoing cardiac surgery between 1997 and 2013. INTERVENTIONS: Comparisons were done in patients with intraoperative nadir Hb<8 g/dL and/or an Hb decrease ≥ 50%. Comparison (A) between Jehovah's Witnesses (Witnesses) and matched non-Jehovah's Witnesses (non-Witnesses) transfused with 1 unit of RBC, and comparison (B) between patients given 1 unit of RBC intraoperatively versus matched non-transfused patients. MEASUREMENTS AND MAIN RESULTS: Postoperative outcomes were myocardial infarction, renal replacement therapy, stroke, and death. With propensity matching, the authors optimized exchangeability of the compared groups. Adverse outcomes increased with a decreasing Hb both among Witnesses and among non-Witnesses. The incidence of postoperative complications did not differ between Witnesses and matched non-Witnesses who received RBC (adjusted odds ratio 1.44, 95% confidence interval 0.63-3.29). Similarly, postoperative complications did not differ between patients who received a red cell transfusion and matched patients who did not (adjusted odds ratio 0.94, confidence interval 0.72-1.23). CONCLUSION: Intraoperative anemia is associated with adverse outcomes after cardiac surgery, and a single RBC transfusion does not seem to influence these outcomes.

The Effect of Dexamethasone on Symptoms of Posttraumatic Stress Disorder and Depression After Cardiac Surgery and Intensive Care Admission: Longitudinal Follow-Up of a Randomized Controlled Trial.

OBJECTIVE: Cardiac surgery and postoperative admission to the ICU may lead to posttraumatic stress disorder and depression. Perioperatively administered corticosteroids potentially alter the risk of development of these psychiatric conditions, by affecting the hypothalamic-pituitary-adrenal axis. However, findings of previous studies are inconsistent. We aimed to assess the effect of a single dose of dexamethasone compared with placebo on symptoms of posttraumatic stress disorder and depression and health-related quality of life after cardiac surgery and ICU admission. DESIGN: Follow-up study of a randomized clinical trial. SETTING: Five Dutch heart centers. PATIENTS: Cardiac surgery patients (n = 1,244) who participated in the Dexamethasone for Cardiac Surgery trial. INTERVENTIONS: A single intraoperative IV dose of dexamethasone or placebo was administered in a randomized, double-blind way. MEASUREMENTS AND MAIN RESULTS: Symptoms of posttraumatic stress disorder, depression, and health-related quality of life were assessed with validated questionnaires 1.5 years after randomization. Data were available for 1,125 patients (90.4%); of which 561 patients received dexamethasone and 564 patients received placebo. Overall, the prevalence of psychopathology was not influenced by dexamethasone. Posttraumatic stress disorder and depression were present in, respectively, 52 patients (9.3%) and 69 patients (12.3%) who received dexamethasone and in 66 patients (11.7%) and 78 patients (13.8%) who received placebo (posttraumatic stress disorder: odds ratio, 0.82; 95% CI, 0.55-1.20; p = 0.30; depression: odds ratio, 0.92; 95% CI, 0.64-1.31; p = 0.63). Subgroup analysis revealed a lower prevalence of posttraumatic stress disorder (odds ratio, 0.23; 95% CI, 0.07-0.72; p < 0.01) and depression (odds ratio, 0.29; 95% CI, 0.11-0.77; p < 0.01) in female patients after dexamethasone administration. Health-related quality of life did not differ between groups and was not associated with psychopathology. CONCLUSIONS: Overall, our findings suggest that exogenous administration of the glucocorticoid receptor agonist dexamethasone-compared with placebo-during cardiac surgery does not positively or negatively affect the prevalence of posttraumatic stress disorder and depression. However, in female patients, beneficial effects on the occurrence of posttraumatic stress disorder and depression may be present.

Intraoperative High-Dose Dexamethasone in Cardiac Surgery and the Risk of Rethoracotomy.

BACKGROUND: Cardiac surgery with the use of cardiopulmonary bypass is associated with a systemic inflammatory response. Intraoperative corticosteroids are administered to attenuate this inflammatory response. The recent Dexamethasone for Cardiac Surgery (DECS) trial could not demonstrate a beneficial effect of dexamethasone on major adverse events in cardiac surgical patients. Previous studies suggest that corticosteroids may affect postoperative coagulation and blood loss, and therefore could influence the risk of surgical reinterventions. We investigated the effects of prophylactic intraoperative dexamethasone treatment on the rate of rethoracotomy after cardiac surgery. METHODS: We performed a post-hoc additional data collection and analysis in the DECS trial. A total of 4,494 adult patients undergoing cardiac surgery with cardiopulmonary bypass were randomly assigned to intravenous dexamethasone (1.0 mg/kg) or placebo. The primary endpoint for the present study was the incidence of any rethoracotomy within the first 30 postoperative days. Secondary endpoints included the reason for rethoracotomy and the incidence of perioperative transfusion of blood products. RESULTS: In the dexamethasone group, 217 patients (9.7%) underwent a rethoracotomy, and in the placebo group, 165 patients did (7.3%; relative risk 1.32, 95% confidence interval: 1.09 to 1.61, p = 0.005). The most common reason for rethoracotomy was tamponade in both groups: 3.9% versus 2.1%, respectively (relative risk 1.84, 95% confidence interval: 1.30 to 2.61, p < 0.001). CONCLUSIONS: Intraoperative high-dose dexamethasone administration in cardiac surgery was associated with an increased rethoracotomy risk.

Intraoperative High-Dose Dexamethasone and Severe AKI after Cardiac Surgery.

Administration of prophylactic glucocorticoids has been suggested as a strategy to reduce postoperative AKI and other adverse events after cardiac surgery requiring cardiopulmonary bypass. In this post hoc analysis of a large placebo-controlled randomized trial of dexamethasone in 4465 adult patients undergoing cardiac surgery, we examined severe AKI, defined as use of RRT, as a primary outcome. Secondary outcomes were doubling of serum creatinine level or AKI-RRT, as well as AKI-RRT or in-hospital mortality (RRT/death). The primary outcome occurred in ten patients (0.4%) in the dexamethasone group and in 23 patients (1.0%) in the placebo group (relative risk, 0.44; 95% confidence interval, 0.19 to 0.96). In stratified analyses, the strongest signal for potential benefit of dexamethasone was in patients with an eGFR<15 ml/min per 1.73 m(2). In conclusion, compared with placebo, intraoperative dexamethasone appeared to reduce the incidence of severe AKI after cardiac surgery in those with advanced CKD.

Defining indications for selective chest radiography in the first 24 hours after cardiac surgery.

OBJECTIVE: In the intensive-care unit (ICU), chest radiographs (CXRs) are frequently obtained routinely for postoperative cardiac surgery patients, despite the fact that the efficacy of routine CXRs is known to be low. We investigated the efficacy and safety of CXRs performed after cardiac surgery for specified indications only. METHODS: In this observational cohort study, we prospectively included all patients who underwent conventional major cardiac surgery by median sternotomy in the year 2012. On-demand CXRs could be obtained during the first postoperative period for specified indications only. A routine control CXR was performed on the morning of the first postoperative day for all patients who had not undergone a CXR before that time. The diagnostic and therapeutic efficacy values were calculated for all CXRs. Differences were tested using Fisher's exact test or χ(2) analysis. RESULTS: A total of 1102 consecutive cardiac surgery patients were included in this study. The diagnostic efficacy of CXRs for major abnormalities was higher for the postoperative on-demand CXRs (n = 301; 27%) than for the routine CXRs taken the morning after surgery (n = 801; 73%) (6.6% vs 2.7%, P = .004). The therapeutic efficacy was higher for the on-demand CXRs, whereas the need for intervention after the next-morning, routine CXRs was limited to 5 patients (4.0% vs 0.6%, P < .001). None of these patients experienced a major adverse event. CONCLUSIONS: Defining clear indications for selective CXRs after cardiac surgery is effective and seems to be safe. This approach may significantly reduce the total number of CXRs performed, and will increase their efficacy.

The value of routine chest radiographs after minimally invasive cardiac surgery: an observational cohort study.

BACKGROUND: Chest radiographs (CXRs) are obtained frequently in postoperative cardiac surgery patients. The diagnostic and therapeutic efficacy of routine CXRs is known to be low and the discussion regarding the safety of abandoning these CXRs after cardiac surgery is still ongoing. We investigated the value of routine CXRs directly after minimally invasive cardiac surgery. METHODS: We prospectively included all patients who underwent minimally invasive cardiac surgery by port access, ministernotomy or bilateral video-assisted thoracoscopy (VATS) in the year 2012. A direct postoperative CXR was performed on all patients at ICU arrival. All CXR findings were noted, including whether they led to an intervention or not. The results were compared to the postoperative CXR results in patients who underwent conventional cardiac surgery by full median sternotomy over the same period. MAIN RESULTS: A total of 249 consecutive patients were included. Most of these patients underwent valve surgery, rhythm surgery or a combination of both. The diagnostic efficacy for minor findings was highest in the port access and bilateral VATS groups (56% and 63% versus 28% and 45%) (p < 0.005). The diagnostic efficacy for major findings was also higher in these groups (8.9% and 11% versus 4.3% and 3.8%) (p = 0.010). The need for an intervention was most common after minimally invasive surgery by port access, although this difference was not statistically significant (p = 0.056). CONCLUSIONS: The diagnostic efficacy of routine CXRs performed after minimally invasive cardiac surgery by port access or bilateral VATS is higher than the efficacy of CXRs performed after conventional cardiac surgery. A routine CXR after these procedures should still be considered.

Association of perioperative troponin and atrial fibrillation after coronary artery bypass grafting.

OBJECTIVES: Prediction of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) may lead to preventive or early treatment and improved outcome. We investigated the association of serial perioperative cardiac troponin T (cTNT) measurements with postoperative AF in patients undergoing CABG. METHODS: In a retrospective analysis of prospectively collected data, 3148 patients undergoing elective CABG were evaluated. cTNT values were routinely determined before the start of surgery (cTNT0), at arrival on the intensive care unit (cTNT1) and 8-12 h later (cTNT2). Measurement of cTNT was continued until the peak value was reached. The development of AF during hospital stay was scored. The association between cTNT (cTNT0, cTNT1, cTNT2 and cTNTmax in first 48 h) and AF was calculated in univariable and multivariable analysis. RESULTS: AF occurred in 1080 (34%) patients. cTNT0, cTNT2 and cTNTmax were significantly and positively associated with postoperative AF (P < 0.001) in a univariable analysis, whereas a trend was seen for cTNT1 (P = 0.051). Advanced age, inotropic support and postoperative infection were independently associated with postoperative AF after logistic regression analysis, but cTNT was not. Categorizing patients by inotropic support into categories of inotropic support duration (none, <48 h, >48 h), the mean cTNT values were significantly higher among patients with AF in each category (all P < 0.001). Perioperative cTNT was significantly higher in patients with postoperative complications, longer hospital stay and reduced in-hospital survival. CONCLUSIONS: Perioperative cTNT is univariably associated with postoperative AF after CABG, but not independently. Further, no clinically useful cut-off point for preventive or early treatment could be identified. Both perioperative cTNT and postoperative AF are associated with negative outcome and prolonged hospital stay.

Intraoperative high-dose dexamethasone for cardiac surgery: a randomized controlled trial.

CONTEXT: Prophylactic corticosteroids are often administered during cardiac surgery to attenuate the inflammatory response to cardiopulmonary bypass and surgical trauma; however, evidence that routine corticosteroid use can prevent major adverse events is lacking. OBJECTIVE: To quantify the effect of intraoperative high-dose dexamethasone on the incidence of major adverse events in patients undergoing cardiac surgery. DESIGN, SETTING, AND PARTICIPANTS: A multicenter, randomized, double-blind, placebo-controlled trial of 4494 patients aged 18 years or older undergoing cardiac surgery with cardiopulmonary bypass at 8 cardiac surgical centers in The Netherlands enrolled between April 13, 2006, and November 23, 2011. INTERVENTION: Patients were randomly assigned to receive a single intraoperative dose of 1 mg/kg dexamethasone (n = 2239) or placebo (n = 2255). MAIN OUTCOME MEASURES: A composite of death, myocardial infarction, stroke, renal failure, or respiratory failure, within 30 days of randomization. RESULTS: Of the 4494 patients who underwent randomization, 4482 (99.7%) could be evaluated for the primary outcome. A total of 157 patients (7.0%) in the dexamethasone group and 191 patients (8.5%) in the placebo group reached the primary study end point (relative risk, 0.83; 95% CI, 0.67-1.01; absolute risk reduction, -1.5%; 95% CI, -3.0% to 0.1%; P = .07). Dexamethasone was associated with reductions in postoperative infection, duration of postoperative mechanical ventilation, and lengths of intensive care unit and hospital stays. In contrast, dexamethasone was associated with higher postoperative glucose levels. CONCLUSION: In our trial of adults undergoing cardiac surgery, the use of intraoperative dexamethasone did not reduce the 30-day incidence of major adverse events compared with placebo. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00293592.

The clinical value of routine chest radiographs in the first 24 hours after cardiac surgery.

BACKGROUND: Chest radiographs (CXRs) are obtained frequently in the intensive care unit (ICU). Whether these CXRs should be performed routinely or on clinical indication only is often debated. The aim of our study was to investigate the incidence and clinical significance of abnormalities found on routine postoperative CXRs in cardiac surgery patients and whether a restricted use of CXRs would influence the number of significant findings. METHODS: We prospectively included all consecutive patients who underwent cardiac surgery during a 2-month period. Two or three CXRs were performed in the first 24 hours of ICU stay. After ICU admission and after drain removal, a clinical assessment was performed before a CXR was obtained. All CXR abnormalities were noted and it was also noted whether they led to an intervention. For the admission CXR and the drain removal CXR, a comparison was made between CXRs clinically indicated by the physician and those not clinically indicated. RESULTS: Two hundred fourteen patients were included. The majority of patients underwent coronary arterial bypass grafting (60%), heart valve surgery (21%), or a combination of these (14%). In total, 534 CXRs were performed (2.5 per patient). Abnormalities were found on 179 CXRs (33.5%) and 13 CXR results led to an intervention (2.4%). The association between clinically indicated CXRs and the presence of CXR abnormalities was poor. For 32 (10%) of the 321 admission and drain removal CXRs, clinical indications were stated by the physician beforehand. If these CXRs would not have been performed routinely, 68 abnormalities would have been missed, of which 5 led to an intervention. CONCLUSIONS: Partial elimination of routine CXRs in the first 24 hours after cardiac surgery seems possible for the majority of patients, but it is limited by the insensitivity of clinical assessment in predicting clinically important abnormalities detectable by CXRs.

Persistent cortical blindness after a thoracic epidural test dose of bupivacaine.

Thoracic epidural anesthesia is considered as an essential component of the perioperative care for patients undergoing lung resection. Although neurologic adverse events have been associated with this technique, permanent injury is rare. These events primarily involve the peripheral nervous system; for example, nerve root injury. We present a case of persistent cortical blindness after a test dose of bupivacaine was administered into an uneventfully placed thoracic epidural catheter.

Ventilator-associated pneumonia in patients undergoing major heart surgery: an incidence study in Europe.

INTRODUCTION: Patients undergoing major heart surgery (MHS) represent a special subpopulation at risk for nosocomial infections. Postoperative infection is the main non-cardiac complication after MHS and has been clearly related to increased morbidity, use of hospital resources and mortality. Our aim was to determine the incidence, aetiology, risk factors and outcome of ventilator-associated pneumonia (VAP) in patients who have undergone MHS in Europe. METHODS: Our study was a prospective study of patients undergoing MHS in Europe who developed suspicion of VAP. During a one-month period, participating units submitted a protocol of all patients admitted to their units who had undergone MHS. RESULTS: Overall, 25 hospitals in eight different European countries participated in the study. The number of patients intervened for MHS was 986. Fifteen patients were excluded because of protocol violations. One or more nosocomial infections were detected in 43 (4.4%) patients. VAP was the most frequent nosocomial infection (2.1%; 13.9 episodes per 1000 days of mechanical ventilation). The microorganisms responsible for VAP in this study were: Enterobacteriaceae (45%), Pseudomonas aeruginosa (20%), methicillin-resistant Staphylococcus aureus (10%) and a range of other microorganisms. We identified the following significant independent risk factors for VAP: ascending aorta surgery (odds ratio (OR) = 6.22; 95% confidence interval (CI) = 1.69 to 22.89), number of blood units transfused (OR = 1.08 per unit transfused; 95% CI = 1.04 to 1.13) and need for re-intervention (OR = 6.65; 95% CI = 2.10 to 21.01). The median length of stay in the intensive care unit was significantly longer (P < 0.001) in patients with VAP than in patients without VAP (23 days versus 2 days). Death was significantly more frequent (P < 0.001) in patients with VAP (35% versus 2.3%). CONCLUSIONS: Patients undergoing aortic surgery and those with complicated post-intervention courses, requiring multiple transfusions or re-intervention, constitute a high-risk group probably requiring more active preventive measures.

Bayesian networks for multivariate data analysis and prognostic modelling in cardiac surgery.

Prognostic models are tools to predict the outcome of disease and disease treatment. These models are traditionally built with supervised machine learning techniques, and consider prognosis as a static, one-shot activity. This paper presents a new type of prognostic model that builds on the Bayesian network methodology that implements a dynamic, process-oriented view on prognosis. In contrast to traditional prognostic models, prognostic Bayesian networks explicate the scenarios that lead to disease outcomes, and can be used to update predictions when new information becomes available. A recursive data analysis strategy for inducing prognostic Bayesian networks from medical data is presented, and applied to data from the field of cardiac surgery. The resulting model outperformed a model that was constructed with off-the-shelf Bayesian network learning software, and had similar performance as class probability trees.

Prognostic Bayesian networks II: an application in the domain of cardiac surgery.

A prognostic Bayesian network (PBN) is new type of prognostic model that implements a dynamic, process-oriented view on prognosis. In a companion article, the rationale of the PBN is described, and a dedicated learning procedure is presented. This article presents an application here of in the domain of cardiac surgery. A PBN is induced from clinical data of cardiac surgical patients using the proposed learning procedure; hospital mortality is used as outcome variable. The predictive performance of the PBN is evaluated on an independent test set, and results were compared to the performance of a network that was induced using a standard algorithm where candidate networks are selected using the minimal description length principle. The PBN is embedded in the prognostic system ProCarSur; a prototype of this system is presented. This application shows PBNs as a useful prognostic tool in medical processes. In addition, the article shows the added value of the PBN learning procedure.

Psychotic symptoms in patients undergoing coronary artery bypass grafting and heart valve operation.

OBJECTIVE: Delirium on internal medicine and surgical wards of the general hospital is associated with several predisposing and precipitating factors as well as adverse outcomes. Whether psychosis, the symptom of delirium that may be recognized most promptly, is similarly associated with these factors and outcomes is largely unknown. METHODS: Eight thousand one hundred and thirty-nine consecutive patients undergoing coronary artery bypass grafting and/or heart valve operation were screened for preoperative predisposing factors and postoperative psychotic symptoms between January 1999 and July 2004. Data on per- and postoperative precipitating factors were collected in 4942 patients enrolled between January 2001 and July 2004. Data were examined using logistic regression to estimate odds ratios. RESULTS: The rate of severe psychotic symptoms was 2.1% (n=168). Higher age, renal failure, dyspnoea, heart failure, and left ventricle hypertrophy were independent preoperative predisposing factors. Peroperative hypothermia (<33 degrees C), hypoxemia, low hematocrit, renal failure, increased sodium, infection and stroke were independent precipitating factors. Psychotic symptoms were independently associated with a prolonged length of stay on the intensive care unit (odds ratio 7.8; 95% confidence interval 5.6-11), multi-organ failure or shock (3.2; 95% CI: 2.2-4.9), cardiopulmonary resuscitation (3.6; 95% CI: 2.1-6.2), and in-hospital death after surgery (2.1; 95% CI: 1.1-4.1). CONCLUSIONS: Psychotic symptoms are independently associated with several chronic and peroperative problems (including mild hypothermia during surgery), closely resembling those for delirium (with and without psychotic symptoms). Psychotic symptoms are also independently associated with adverse outcomes. Prompt diagnostic and therapeutic intervention aimed at the underlying problem may improve outcomes.

A phase III, double-blind, placebo-controlled, multicenter study on the efficacy of recombinant human antithrombin in heparin-resistant patients scheduled to undergo cardiac surgery necessitating cardiopulmonary bypass.

BACKGROUND: The study evaluated the efficacy of recombinant human antithrombin (rhAT) for restoring heparin responsiveness in heparin resistant patients undergoing cardiac surgery. METHODS: This was a multicenter, randomized, double-blind, placebo-controlled study in heparin-resistant patients undergoing cardiac surgery with cardiopulmonary bypass. Heparin resistance was diagnosed when the activated clotting time was less than 480 s after 400 U/kg heparin. Fifty-four heparin-resistant patients were randomized. One cohort received 75 U/kg rhAT, and the other received normal saline. If the activated clotting time remained less than 480 s, this was considered treatment failure, and 2 units fresh frozen plasma was transfused. Patients were monitored for adverse events. RESULTS: Only 19% of patients in the rhAT group received fresh frozen plasma, compared with 81% of patients in the placebo group (P < 0.001). During their hospitalization, 48% of patients in the rhAT group received fresh frozen plasma, compared with 85% of patients in the placebo group (P = 0.009). Patients in the placebo group required higher heparin doses (P < 0.005) for anticoagulation. There was no increase in serious adverse events associated with rhAT. There was increased blood loss 12 h postoperatively (P = 0.05) with a trend toward increased 24-h bleeding in the rhAT group (P = 0.06). There was no difference between the groups in blood and platelet transfusions. CONCLUSION: Treatment with 75 U/kg rhAT is effective in restoring heparin responsiveness and promoting therapeutic anticoagulation in the majority of heparin-resistant patients. Treating heparin-resistant patients with rhAT may decrease the requirement for heparin and fresh frozen plasma.