Showing papers by "Peter Feindt published in 2009"

Predictors and outcome of ICU readmission after cardiac surgery.

Abstract: Objective Readmission to the intensive care unit (ICU) after cardiac surgery is associated with higher costs and may be correlated with an increased mortality. We wanted to evaluate predictors of ICU readmission and to analyze the outcome of those patients. Methods 3523 patients who underwent CABG and/or valve surgery between 2004 and 2007 were reviewed retrospectively. The reasons for readmission and the postoperative course were analyzed. Furthermore, perioperative risk factors for readmission were determined by multivariate regression analysis. Results Of the 3374 patients discharged from the ICU, 5.9 % (198) of patients required a second stay in the intensive care (group r). The readmission rate was 4.8 % following CABG and 8.9 % following valve +/- CABG ( P 24 h, reexploration for bleeding and low cardiac output state were independent predictors for readmission. Conclusions Patients after valve/combined surgery are more likely to require readmission to the ICU. Respiratory complications were the most common reasons for readmission. To reduce the readmission rate, it is necessary to treat cardio-respiratory problems early, particularly in patients showing predictive risk factors.

Intraaortic balloon pumping in patients with right ventricular insufficiency after cardiac surgery: parameters to predict failure of IABP Support.

Abstract: BACKGROUND The indications for intra-aortic balloon pump (IABP) in the case of a failing right ventricle after operations with extracorporeal circulation (ECC) are still discussed controversially. We investigated the benefit of IABP in patients with a predominantly right ventricular dysfunction after ECC. Additionally, we wanted to identify early and easily available prognostic markers for outcome in all patients receiving IABP support. PATIENTS AND METHODS Between 1/2004 and 1/2008, 4550 patients underwent cardiac surgical procedures with ECC, 223 of whom (4.9 %) had an IABP inserted intra- or postoperatively (group 1). 79 of these patients were treated intraoperatively with IABP for early postoperative low cardiac output syndrome (LCOS) characterized by predominantly right ventricular failure (RV group). Clinical data and hemodynamic variables were recorded perioperatively. Multiple potential markers of mortality and postoperative complications were analyzed statistically, especially with regard to their predictive ability. RESULTS 68 % of all IABP patients were successfully weaned from IABP support and 63 % survived to hospital discharge. In the RV group, cardiac index (CI) and mean arterial pressure (MAP) increased (CI 1.8 +/- 0.2 to 2.8 +/- 0.2, MAP 53 +/- 10 to 73 +/- 8, P 17 mmHg or a mixed venous saturation (SVO (2)) < 65 % had poor outcomes. CONCLUSIONS In patients with IABP support for postcardiotomy cardiogenic shock, elevated serum lactate, elevated base deficit, hypotension, oliguria and large vasopressor doses are all predictors of mortality. In these patients, the use of another mechanical assist device should be considered in good time. Our study additionally shows that LCOS caused by predominantly right ventricular failure - particularly after CABG - may be an additional indication for IABP.

The Impact of Pre- and Postoperative Renal Dysfunction on Outcome of Patients Undergoing Coronary Artery Bypass Grafting (CABG)*

Abstract: OBJECTIVE Acute changes in renal function after elective coronary bypass surgery represent a challenging clinical problem. In this study, we evaluated perioperative risk factors for the development of postoperative renal dysfunction (PRD), and the impact of such an event on the perioperative course. Additionally, we investigated the influence of preoperatively mildly increased serum creatinine on perioperative mortality and morbidity. METHODS We retrospectively analyzed data of 2511 patients undergoing isolated CABG between 2004 and 2007 with a preoperative serum creatinine < or = 2.2 mg/dL. There were 592 patients with a preoperative serum creatinine of between 1.4 and 2.2 mg/dl (mild renal dysfunction group) and 1919 patients with a serum creatinine < 1.4 mg/dl. Perioperative risk factors for PRD were analyzed by multivariate regression analysis. RESULTS Global in-hospital mortality was 3.1 %.The incidence of PRD was 6.2 %. Mortality for patients who had PRD was 7.8 vs. 2.9 % for patients who did not ( P < 0.05). PRD increased the length of hospital stay by 3.7 days (12.2 vs. 15.9; P < 0.05). Multivariate logistic regression identified the following variables as independent predictors of PRD: age, angina class III/IV, diabetes mellitus, prolonged cardiopulmonary bypass time, and preoperative serum creatinine. With regard to preoperative renal function, we found that operative mortality was higher in the mild renal dysfunction group (5.7 % vs. 2.5 %; P < 0.05). New dialysis/hemofiltration (5.1 % vs. 1.2 %; P < 0.05) and postoperative stroke (5.1 % vs. 1.6 %; P < 0.05) were also more common in these patients. CONCLUSIONS Mild renal dysfunction preoperatively is an important predictor of outcome after CABG. In these patients, PRD dramatically increases mortality, morbidity and length of hospital stay.

Cardiac valve replacement in patients with end-stage renal failure: impact of prosthesis type on the early postoperative course.

Abstract: BACKGROUND It is still unclear whether biological or mechanical valves should be preferred in patients on chronic dialysis therapy. PATIENTS AND METHODS We retrospectively analyzed data from 104 patients (66.5 +/- 8.6 years) with end-stage renal failure (RF) who underwent aortic or mitral valve replacement between 2002 and 4/2008. Mechanical valves were implanted in 44 (42 %) patients and bioprostheses in 60 (58 %). The two groups were comparable with regard to preoperative data, age and incidence of additional CABG procedures. We studied in-hospital morbidity and mortality, major postoperative complications and length of ICU and hospital stay. Additionally, parameters predicting a poor outcome were analyzed with multivariate regression analysis. RESULTS The overall hospital mortality was 12.5 % and did not differ between the two groups (mechanical: 13.6 %, biological: 11.7 %, n. s.). In the postoperative course, duration of ventilation and ICU stay were similar, whereas hospital stay was significantly longer for patients with mechanical prostheses (19.5 +/- 5.4 vs. 15.6 +/- 4.1 days, P < 0.05). Mechanical valve patients had a significantly higher rate of postoperative cerebrovascular incidents (18.2 vs. 8.3 %, P < 0.05) and bleeding complications (15.9 vs. 11.7 %, P < 0.05). Reoperation, obesity, left ventricular ejection fraction < 30 % and previous neurological complications were independent predictors of hospital mortality. CONCLUSIONS Our results demonstrate that in patients with end-stage RF, the use of mechanical valves is associated with a significant risk of complications. Because of the poor overall survival of patients on dialysis, bioprosthesis degeneration will not be a limiting factor. Therefore, preference should be given to biological valves in these patients.

The use of autologous platelet gel (APG) for high-risk patients in cardiac surgery — is it beneficial?:

Abstract: Background: Wound healing in cardiac surgery has become a major problem due to the impaired risk profile of many patients. The aim of this study was to prove the influence of autologous platelet ge...

Impact of mitral valve repair in patients with mitral regurgitation undergoing coronary artery bypass grafting

Abstract: BACKGROUND The benefit of concomitant mitral valve correction (replacement or reconstruction, MVR) and coronary artery bypass grafting (CABG) in patients with coronary artery disease and mitral regurgitation (MR) remains unclear. PATIENTS AND METHODS 298 consecutive patients underwent CABG alone (n=196) or CABG+ MVR (n=102) between January 2003 and April 2008. Clinical data were collected and MR graded according to preoperative echocardiographic studies. Four severity grades of MR were determined and patients assigned accordingly. Echocardiographic follow-up was performed postoperatively to assess heart and valve function. Multivariate logistic regression analysis was performed for perioperative morbidity and mortality. RESULTS Patients were comparable within the groups regarding age, gender, NYHA-class, ejection fraction and number of graft vessels. Perioperative mortality (10.8% vs. 5.1%, P < 0.05) and degree of MR were higher among CABG+MVR patients. Among patients with moderate to severe or severe MR, postoperative echocardiography showed an improvement of mitral regurgitation in 95% of CABG+MVR and in 64% of CABG only patients. In patients with mild or moderate MR, improvement rates of both groups were similar (74% and 69%, respectively). Postoperatively, ejection fraction increased in both groups (CABG+MVR: 31.3 +/- 8.5 to 36.4 +/- 11.2; CABG only: 29.9 +/- 6.1 to 33.3 +/- 8.1, P > 0.05). Significant predictors for peri-operative mortality were renal insufficiency, older age and NYHA class III/IV. CONCLUSIONS For reduction of ischaemic MR, CABG+MVR is preferable in patients with moderate to severe or severe MR. Combined CABG+MVR procedures cannot be recommended for patients with a particular risk profile because of disproportionately high peri-operative mortality.

Aortic blood flow characteristics of different extracorporeal circulation techniques during cardiac surgery - a computational fluid dynamics study

Abstract: Extracorporeal circulation is a standard technique in cardiac surgery. Nevertheless, many different variations have been developed. Using computational fluid dynamics the impact of a particular perfusion technique can be simulated preoperatively. The aim of our study was to examine changes of the blood flow characteristics when perfusing the aorta with different techniques. At first we created a numerical model of a human aorta and its outlets. Then we performed simulations of antegrade pulsatile and non-pulsatile blood flow and simulated antegrade and retrograde perfusion via extracorporeal circulation canulas. At perfusion originating from canulas the flow became turbulent and its speed regionally increased up to 3,54 m/s. Otherwise perfusing retrogradely only marginal blood flow remained in the ascending aorta. Canula stream caused up to ten-fold higher local wall shear stress values, especially in the vessel roots next to the canulas and in the proximate aortic wall. Under these conditions mobilization of arteriosclerotic plaques has to be considered. Our study shows that antegrade and retrograde perfusion via canulas change important blood flow characteristics as flow speed, turbulent stream and wall shear stress.

Intermediate coronary revascularization using the Deltastream blood pump: results from an experimental study.

Abstract: BackgroundMyocardial revascularization using a complete heart-lung machine may involve many problems, as do complete off-pump attempts. Thus, it was the aim of this study to evaluate the effects of...