Fluid responsiveness and right ventricular function in cardiac surgical patients. A multicenter study.

INTRODUCTION: We investigated fluid responsiveness in a population of patients undergoing coronary artery revascularization, with respect to their right ventricular ejection fraction. MATERIALS AND METHODS: This was a multicenter trial involving 11 cardiac surgical Institutions and 65 patients undergoing elective coronary artery revascularization. Hemodynamic parameters were measured before and after volume expansion using a modified pulmonary artery catheter and transesophageal echocardiographic monitoring. Patients demonstrating an increase of stroke volume >20% after volume expansion were considered as responders. Volume expansion with 7 ml/kg of plasma expander was performed when required on a clinical basis. RESULTS: In the overall population, only the change in aortic blood velocity (cut-off 13%) was a predictor of fluid responsiveness. In patients with a reduced (<0.3) right ventricular ejection fraction only the value of mean pulmonary arterial pressure was predictive of fluid responsiveness (cut-off 18 mmHg). Patients with right ventricular ejection fraction ≥0.3 demonstrated three predictors: changes in aortic blood velocity (cut-off 15%), right ventricular end diastolic volume index (cut-off 80 ml/m(2)), and left ventricular end diastolic area index (cut-off 9 cm(2)/m(2)). CONCLUSIONS: When right ventricular systolic function is depressed, the right ventricle inability to fill the left chambers results in a lack of the left-sided responsiveness predictors. When the right ventricular systolic function is preserved, all the classical fluid responsiveness predictors are confirmed. Right ventricular function is therefore to be always considered when addressing the problem of fluid responsiveness.

Predictors of prolonged mechanical ventilation in a cohort of 3,269 CABG patients.

BACKGROUND: Prolonged mechanical ventilation after heart surgery is associated with increased patient morbidity and mortality (4.9% vs 22-38%). A prospective observational cohort study was carried out to assess the predictors of prolonged mechanical ventilation and its impact on hospital survival in a cardiac surgical patient cohort admitted to our 8 bed postoperative ICU from January 1997 through June 2004. METHODS: All of the patient perioperative and ICU variables were input into an electronic database. Patients were divided into: 1) an Early Extubation group, undergoing a successful extubation within 12 h and 2) a Delayed Extubation group, needing mechanical ventilation longer than 12 h. RESULTS: A total of 3,269 patients undergoing a coronary artery bypass graft operation were admitted. A multivariate Logistic Regression model allowed us to identify: 1) redo surgery (OR = 3.090, 95% CI = 1.655-5.780); 2) cardiopulmonary bypass time longer than 91' (OR = 1.390, 95% CI = 1.013-1.908); 3) intraoperative transfusions of more than 4 units of red blood cells (OR = 3.144, 95% CI = 2.331-4.255) or fresh frozen plasma (OR = 2.976, 95% CI = 1.984-4.830); and 4) left ventricular ejection fraction = or < 30% (OR = 2.444, 95% CI 1.291-3.205) as independent predictors of prolonged mechanical ventilation. The Early Extubation group showed a significantly higher cumulative survival 180 days after the ICU admission (Log-Rank = 16.617, p=0.000). CONCLUSION: This audit allowed us to assess a predictive model identifying a priori coronary artery bypass graft patients that are more likely to undergo prolonged mechanical ventilation.

Two consecutive cases of type A aortic dissection after delivery.

Aortic dissection occurs when blood penetrates the aortic intima and forms an expanding hematoma within the vessel wall, separating the intima and media to create a so-called false lumen. Aortic dissection has been estimated to cause one of every 10,000 hospital admissions. The survival rate of untreated patients with aortic dissections is dismal, with a 2-day mortality of up to 50%. The medical conditions predisposing a patient to aortic dissection are hypertension, advanced age, sex, Marfan syndrome and some forms of congenital heart disease. Pregnancy and delivery are not considered major risk factors for the disease. We report here two consecutive cases of type A aortic dissection (Stanford classification) in young puerperal patients after elective caesarean section.

Intra-aortic balloon counterpulsation: outcome in cardiac surgical patients.

OBJECTIVE: To identify the major determinants of survival and nonsurvival for patients in need of intra-aortic balloon pump (IABP) support after cardiac surgery and to define the role of ventilator-associated pneumonia. DESIGN: Retrospective study. SETTING: University and general hospital. PARTICIPANTS: A total of 105 consecutive patients undergoing cardiac surgery requiring IABP support and prolonged mechanical ventilation for >24 hours. INTERVENTION: All patients were assigned into 1 of 2 groups: survival (n = 69) and nonsurvival (n = 36). MEASUREMENTS AND MAIN RESULTS: Differences between the survival and nonsurvival groups were tested with the Student's t-test, chi-square test, and frequency analysis. The overall survival rate was 65.7%. Nonsurvivors (34.3%) had higher rates of acute myocardial infarction (27.7% v 4.3%; p < 0.002), Canadian Cardiovascular Society functional class III and IV (44.4% and 13.8%; p < 0.001), and depressed left ventricular ejection fraction (31.3 +/- 6.4% v 42.4 +/- 7.2%; p < 0.001). The nonsurvival group had longer duration of cardiopulmonary bypass (165 +/- 74.3 minutes v 135 +/- 36 minutes; p < 0.006) and aortic occlusion (81.8 +/- 9 minutes v 68.6 +/- 25.7 minutes; p < 0.004). In the nonsurvival group, 21 patients were not weaned from the IABP, and 15 patients were weaned from the IABP but died from renal failure (26.6%), multiorgan failure (13.3%), infection, and respiratory failure (66.6%). In the nonsurvival group, mechanical ventilation time was longer in patients weaned from the IABP. CONCLUSION: These data suggest that for patients not weaned from the IABP, the major determinants of death are low cardiac output (33.3%) and multiorgan failure (47.6%). Patients with a left ventricular ejection fraction of <30% have a poorer outcome. In patients weaned from the IABP, ventilator-associated pneumonia (66.6%) was the major cause of death.

Myocardial revascularization with multiple arterial grafts: comparison between the radial artery and the right internal thoracic artery.

BACKGROUND: Bilateral internal thoracic artery (ITA) harvesting is significantly underused, whereas the radial artery is being used with increasing frequency. We have retrospectively analyzed perioperative and short-term outcomes of patients receiving a radial artery versus those receiving a right ITA as a second arterial graft. METHODS: Between February 1999 and May 2000, 250 patients underwent coronary artery bypass grafting using the radial artery (156 patients) or the right ITA (94 patients) in combination with the left ITA and, when required, the saphenous vein. RESULTS: There was a higher prevalence of risk factors in the radial artery group. More coronary artery bypass graftings (p < 0.001) were performed with the radial artery. Operative mortality was not different (p = not significant). In the right ITA group there was more bleeding (p < 0.001) and a longer hospital stay (p < 0.001). Mean follow-up was 8.1 +/- 3.9 months. The probability of survival was similar (p = not significant). CONCLUSIONS: The radial artery can extend the benefits of multiple arterial grafting to those patients who are usually excluded from bilateral ITA harvesting because of multiple risk factors. Perioperative and short-term results are good.

Immediate and long-term results of coronary revascularization in patients undergoing chronic hemodialysis.

OBJECTIVE: To evaluate morbidity and long-term survival in end stage renal disease (ESRD) patients, undergoing coronary artery bypass graft surgery. METHODS: We identified 22 such patients who underwent bypass grafting between 1987 and 1997. Symptomatic status of angina was rated using the classification of the Canadian Cardiovascular Society (CCS) and the functional status, was assessed using the Karnofsky scoring system. The patients were hemodialyzed the day before surgery and 24-48 h after surgery. RESULTS: Two patients operated on for acute myocardial infarction died after 4 days. Follow-up was completed in the remaining 20 patients (the mean follow-up time was 25+/-15 months). The survival rates at 1, 2 and 3 years was 84.5%, 74% and 59%, respectively. The symptoms diminished and the functional status was significantly improved. CONCLUSION: We conclude that elective coronary artery bypass in dialysis patients can be performed with acceptable morbidity and mortality. We advocate early surgical treatment. However, long-term survival is limited and this requires further investigation.

Left ventricular volume reduction for end-stage heart disease.

Partial left ventriculectomy (PLV) was recently introduced for end-stage dilated cardiomyopathy to improve ventricular function. Since November 1996 we have performed PLV in 14 patients; preoperatively 4 patients had idiopathic dilated cardiomyopathy and 10 had ischemic dilated cardiomyopathy. 57.1% of patients were in New York Heart Association functional Class IV. The mitral valve was replaced in 11 patients. Postoperative echocardiography showed a reduction of left end-diastolic diameter (55.4 +/- 5.4 mm) and an increase in forward ejection (cardiac index from 2.19 +/- 0.571 min/m2 to 2.67 +/- 0.931/min/m2). The 30-day mortality was 28.6% and 20-month survival was 57.2%. Only one patient was not in NYHA functional class due to postoperative progressive mitral incompetence. Prognostic factors should be identified to avoid early failure. However, even if the mortality rate for PLV high, this operation is a valid choice for the treatment of end-stage dilated cardiomyopathy.

Improvement of cardiac function by allopurinol in patients undergoing cardiac surgery.

Allopurinol reduces formation of cytotoxic free radicals during myocardial ischemia/reperfusion in animals. To evaluate the effect of allopurinol on cardiac performance and metabolism after coronary bypass in humans, we divided 33 patients into two groups: 15 patients (controls) received no allopurinol and 18 patients received 200 mg allopurinol intravenously (i.v.) 1 h preoperatively. Hemodynamic measurements were made with a triple-lumen thermodilution pulmonary artery catheter before cardiopulmonary bypass (CPB), 30 min after completion of CPB and 6 h later in the intensive care unit (ICU). A catheter placed into the coronary sinus was used for blood sampling for measurement of lactate and creatine phosphokinase MB. Peripheral blood was obtained for measurement of xanthine oxidase activity (XO), uric acid, and thiol groups. A myocardial biopsy was taken for measurement of thiol group content and XO before CPB and after heparin neutralization with protamin (a few minutes after CPB). Treated patients had better recovery of cardiac output (CO) and left ventricular stroke work (LVSW) 30 min and 6 h after completion of CPB than did controls. Allopurinol significantly reduced plasma XO. Plasma concentrations of uric acid increased significantly in both groups 30 min after completion of CPB, but the increase in controls was greater (p < 0.02) than with allopurinol. Thiol group levels increased (p < 0.05) only in controls. Our results demonstrate improvement of cardiac function in coronary artery bypass surgery with allopurinol that is related to its metabolic effects consistent with protection against XO catalyzed free radical-mediated injury.

[Autologous blood transfusion in elective heart surgery: prospective study of 189 consecutive patients]. / L'autoemotrasfusione in cardiochirurgia elettiva: studio prospettico in 189 pazienti consecutivi.

Blood autotransfusion has entered a new phase in blood transfusion technique, since it represents an important alternative in eliminating the risks connected with blood transfusion: viral hepatitis, AIDS, blood transfusion reactions, and alloimmunization. Transfusion requirements during cardiac surgical procedures have steadily decreased; nowadays most adult patients require no transfusion during surgery. Patients (pts) receiving bank-blood may develop infectious diseases (hepatitis, AIDS, etc.). We have studied how to avoid the risk of infections with homologous blood transfusions. We present our experience of day-hospital pre-operative autologous blood collection. One-hundred-eighty-nine patients undergoing primary myocardial revascularization or valvular replacement were submitted to the drainage of 350 ml of blood three times every four days before surgery. The blood was centrifuged at once, to separate red cells from plasma. Surgeries were performed 21 days after the first drainage; iron therapy was recommended. After surgery pts received blood only if haematocrit was lower than 28%. The following data were recorded: no. of pts who received homologous blood; blood loss and homologous total blood volume used for each pt. Average blood loss was 1230 cc for ischemic pts and 701 cc for valvular pts. Non-A non B hepatitis occurred in 3/189 pts (1.5%). All of them had received homologous blood transfusions. Our data show clearly that autotransfused pts had a better post-operative period; less bank-blood and fewer transfusions have been used. No pt had collateral effects such as angina or hypotension from blood drawing. Our data show that severe cardiac diseases do not represent an absolute contraindication to heavy blood drainage.(ABSTRACT TRUNCATED AT 250 WORDS)

[Importance of pupillary and photomotor reflexes in cardiac resuscitation]. / Importanza dei riflessi pupillari durante la rianimazione cardiocircolatoria.

The Authors present twenty cases of cardiac arrest which underwent cardio-respiratory resuscitation. The study of pupillary diameter and photomotor reflex are of easy detection and may be of relevant prognostic value during the resuscitation itself.