Elective Open Heart Surgery Research Articles

Effects of rabeprazole or famotidine during cardiac surgery on perioperative gastric and esophageal pH readings

Upper gastrointestinal bleeding, particularly from a stress-induced duodenal ulcer, is an extremely important perioperative complication in cardiovascular surgery. In the present study, 33 patients undergoing elective open heart surgery between July 2000 and February 2001 were allocated to either a famotidine (FAM) or rabeprazole (RPZ) group to examine the perioperative gastric and esophageal pH readings, in conjunction with an investigation into the effect of infection with Helicobacter pylori (HP). Postoperative upper gastrointestinal bleeding did not occur in either group, and the intraoperative and postoperative mean gastric pH readings, as well as the holding time pH>6, suggested sufficient acid suppression by either drug. Gastric acid secretion was less strongly suppressed in HP-negative patients in the FAM group, but was unaffected by HP infection status in the RPZ group. The FAM group and RPZ group revealed a sufficient effect of gastric acid suppression. It was indicated that FAM had an insufficient effect of gastric acid suppression for HP-negative patients.

Gender Analysis After Elective Open Heart Surgery: A Two-Year Comparative Study of Quality of Life

The aim of this prospective study, based on the iterative completion of the 36-item short form health survey questionnaire (SF36) after open heart surgery, was twofold: to evaluate the changes in quality of life (QOL) scores (over time and by gender, and also in comparison with scores from a normal population) and to identify possible gender differences in two-year cardiac functional status. From July 2000 to July 2002, 590 elective patients were included in this study. Baseline and follow-up QOL surveys were obtained for 439 patients (307 males and 132 females). The QOL scores were compared by gender, by analysis of variance, and by the Student t test. Factors influencing two-year cardiac functional status were determined by logistic regression. The comparison of baseline and follow-up scores showed a significant improvement (a sharp increase between baseline and year one, then stabilization) in all dimensions of the SF36, two years after surgery in all patients. However, QOL was significantly lower in women than in men in all but two dimensions; at baseline and during follow-up. When compared with the normal population, men and women over 75 had a similar QOL. The best independent predictive factor of two-year cardiac functional status in women was the physical component summary score and in men, the mental component summary score. The benefit of open heart surgery at two-year follow-up is equivalent in both genders in terms of QOL, although women had lower baseline QOL scores.

Prognostic value of plasma N-terminal pro-brain natriuretic peptide in children with congenital heart defects and open-heart surgery

To assess whether preoperative and postoperative plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) predict postoperative outcome of open-heart surgery in children. A prospective observational study was conducted with 40 children with congenital heart defects who were undergoing elective open-heart surgery. Plasma levels of NT-proBNP, troponin T, lactate, C-reactive protein, and total neutrophil cell counts were measured before, during, and 1 and 3 hours after the end of cardiopulmonary bypass grafting (CPB). Outcomes were assessed by means of the kind, dosage, and duration of inotropic drug use during the postoperative period, lactate concentrations, and the duration of mechanical ventilation. Preoperative levels of NT-proBNP were significantly increased irrespective of the type of congenital heart defect and the age of the patient. Preoperative NT-proBNP levels were higher in patients receiving prolonged postoperative inotropic drug therapy (r = 0.56, P = .0003). By means of multivariate analysis with the duration of inotropic therapy as the dependent variable, a significant impact of preoperative NT-proBNP levels, the presence of a cyanotic heart defect, the risk adjustment for congenital heart surgery score, duration of CPB time, and postoperative lactate levels were demonstrated (R squared = 76.8%, P <.0001). Preoperative NT-proBNP levels were associated with complicated postoperative outcome in children who underwent low-risk open-heart surgery. This marker may therefore be a useful tool in risk stratification of patients with congenital heart defects.

Effect of topical tranexamic acid in open heart surgery

Cardiopulmonary bypass is known to induce postoperative coagulopathy including fibrinolysis. We have evaluated the effect of the topical use of tranexamic acid in the pericardial cavity on postoperative bleeding following open heart surgery. One hundred patients, scheduled for elective open heart surgery, were included in this double-blind, prospective, randomized, controlled study. They were allocated to a treatment group (Group I), or placebo group (Group II). Patients with coagulopathies, renal failure, re-do surgery, or recent anti-platelet treatment were excluded. In Group I, tranexamic acid (2 g in 100 mL of saline solution) was poured into the pericardial cavity before sternal closure. Placebo patients received 100 mL of saline. Postoperative blood loss, need for transfusion of blood products and the rate of re-sternotomy for bleeding were documented. During the first postoperative 24 h, cumulative blood loss was significantly higher in Group II compared to Group I (1208 +/- 121 mL vs. 733 +/- 93 mL, respectively) (P < 0.001). More blood transfusions were administered to Group II patients (4.54 +/- 1.4 units) as compared to Group I patients (2.64 +/- 1.5 units) (P < 0.01). Topical application of tranexamic acid in patients undergoing primary open heart surgery led to a significant reduction of both postoperative mediastinal bleeding, and rate of re-exploration for haemostasis.

A decision aid for autologous pre-donation in cardiac surgery—a randomized trial

Objectives The objective of this randomized, controlled study was to determine the usefulness of a decision aid on pre-donation of autologous blood before elective open heart surgery. Methods The decision aid (DA) group received a tape and booklet which described the options for peri-operative transfusion in detail. The no decision aid (NDA) group received information usually given to patients about autologous donation. Results A total of 120 patients were randomized. The DA group rated themselves better prepared for decision making and showed significant improvements in knowledge ( p = 0.001) and realistic risk perceptions ( p = 0.001). In both groups there was an increase in the proportion of patients choosing allogeneic blood between baseline and follow-up ( p = 0.001). Patients in the DA group were significantly more satisfied with the amount of information they received, how they were treated and with the decision they made, than patients in the NDA group. Conclusion The decision aid is useful in preparing patients for decision making. Practice implications The next stage is to explore strategies to make it available to all appropriate patients.

The composition of normal pericardial fluid and its implications for diagnosing pericardial effusions

Background Pericardial fluid obtained at pericardiocentesis is often subjected to biochemical and hematological analysis, and interpreted using criteria borrowed from pleural effusions. However, the validity and diagnostic yield of this approach is uncertain. Moreover, there is little data regarding the normal composition of the physiological pericardial fluid, which could serve as a reference for pathological effusions. Methods Pericardial fluid from 30 patients undergoing elective open heart surgery was collected. Patients were excluded if they had known pericardial disease, had systemic disorders known to be associated with pericardial disease, or if the fluid samples were hemolytic. The biochemical and hematological parameters of the fluid were determined using standard laboratory techniques, and compared with the results obtained for concurrently drawn venous blood. Results The median age of the study population was 64.5 ± 10.6 years. Chemistry results of soluble molecules were consistent with the plasma ultrafiltrate nature of the fluid. However, fluid lactate dehydrogenase (LDH) level was unexpectedly high, averaging 2.4 times the serum level, and the mean protein level was 0.6 of the serum level. No correlation was found between comorbidities of patients and fluid characteristics. Fluids contained an average of 1430 leukocytes/μL, with a differential count that was predominated by lymphocytes (53.2 ± 14%) and monocytes (11.6 ± 6%). Conclusions The composition of the physiologic pericardial fluid is remarkable for high LDH and protein content, and for predominance of lymphocytes. Thus, the biochemical criteria useful for diagnosing pleural effusions are probably not applicable for differentiating transudative from exudative pericardial effusions, and lymphocytosis should be interpreted cautiously.

Cardiac troponin T for prediction of short- and long-term morbidity and mortality after elective open heart surgery.

Increased cardiac troponins in blood are observed after virtually every open heart surgery, indicating perioperative myocardial cell injury. We sought to determine the optimum time point for blood sampling and the respective cutoff value of cardiac troponin T (cTnT) for risk assessment in patients undergoing cardiac surgery. In a series of 204 patients undergoing scheduled open heart surgery, mainly for coronary artery bypass grafting (n = 132) or valve repair (n = 27), cTnT concentrations were measured before and 4 and 8 h after cross-clamping and then daily for 7 days. Individual risk was assessed by use of the Cleveland Clinic Foundation Risk score and intraoperative risk indicators such as duration of cardiopulmonary bypass, cross-clamping, and perioperative release of cardiac markers. Patients were followed for 28 months. Cardiac mortality, all-cause mortality rates, and rates of nonfatal acute myocardial infarction (AMI) at 28 months were 6.9%, 8.8%, and 6.8%, respectively. cTnT was higher in patients with Q-wave AMI or postoperative heart failure requiring inotropic support, and in nonsurvivors. The ROC curve revealed a cTnT > or = 0.46 microg/L at 48 h as the optimum discriminator for long-term cardiac mortality. Stepwise logistic regression identified higher Cleveland Clinic Risk Score [odds ratio (OR) = 2.6 per point], cross-clamp time >65 min (OR = 6.6), and cTnT (OR = 4.9) as significant and independent predictors of long-term cardiac mortality. A single postoperative cTnT measurement can be used to estimate myocardial cell injury that impacts long-term survival after open heart surgery. It adds independently to established risk indicators.

Aortic/Radial Arterial Pressure Difference during Weaning from Cardiopulmonary Bypass in Open Heart Surgery Patients Anesthetized with Propofol-Alfentanil

Background: Cardiovascular drugs are frequently used to assist myocardial function after discontinuation of cardiopulmonary bypass (CPB) in the open heart surgery (OHS) because of unstable hemodynamics. At this time we should always consider that the radial arterial pressure (RAP) may be lower than the aortic pressure (AP). In this study we evaluated the difference between AP and RAP in propofol-alfentanil anesthesia. Methods: 28 patients undergoing elective OHS were randomly allocated into a midazolam-fentanyl (MA) group (n = 14) or a propofol-alfentanil (PA) group (n = 14). Anesthesia in the MF group consisted of midazolam and fentanyl with intermittent bolus injection, and anesthesia in the PA group consisted of propofol and alfentanil with continuous in fusion. RAP and AP in the two groups were recorded for 5 minutes after CPB discontinuation. Results: No significant difference was founded between the two groups in age, weight, height, CPB time, aortic cross clamping (ACC) time, or temperature. There was a relatively high correlation between the difference of systolic AP-RAP and CPB time (r = 0.01), and ACC time (0.001). The systolic and mean blood pressure difference between the aorta and the radial artery in the MF group was significantly greater than in the PA group. Conclusions: This findings suggest that propofol-alfentanil anesthesia in OHS may be more helpful for hemodynamic management after CPB discontinuation than midazolam-fentanyl anesthesia.

Left atrial Maze procedure: a useful addition to other corrective operations

Background The left atrial maze procedure is performed to treat atrial fibrillation (AF), mainly in patients with mitral valve disease. In this study, we assessed the midterm results of this procedure and clinically analyzed predicting factors for postoperative persistent AF. Methods From June 1997 to May 2001, the left atrial maze procedure was performed on 31 patients (29 with mitral valve disease and 2 lone AF). For purposes of analysis, patients were divided postoperatively into those with persistent atrial fibrillation (AF) and those with sinus rhythm (SR), except 2 patients who required pacemaker implantation for sinus node dysfunction. Over a follow-up period of more than 12 months, patients were compared based on their preoperative and intraoperative variables. Results At discharge, the success rate was 89.7%. The midterm rates (total of 94.9 patient-years of follow-up) of sinus rhythm and freedom from AF were 72.4% and 79.3%, respectively. There were significant differences in duration of AF, voltage of f-wave at first precordial lead of electrocardiogram, and cardiothoracic ratio between the SR and AF groups. Conclusions Our midterm results suggest that the left atrial maze procedure is an effective alternative adjunct procedure for elective open heart surgery to treat AF, depending upon the patient’s clinical condition.

Universal solvent/detergent-treated fresh frozen plasma (Uniplas®)—rationale and clinical properties

Transfusions with incompatible blood products including plasma are a well-known problem. The present study was performed to test the effects of Uniplas®, universal plasma that can be transfused regardless of a patient's blood group, with respect to bleeding and hemostatic activity. The study comprised 84 adult patients scheduled for elective openheart surgery. A total of 55 patients received plasma transfusions, while 29 patients not requiring plasma served as controls. If plasma transfusion was indicated during operation or over the two following days, patients were randomised 2:1 to receive Uniplas® or Octaplas® of blood group AB. Relevant clinical observations were recorded and blood tests taken repeatedly. The transfused patient groups were comparable, and no significant differences were observed with respect to activated clotting time (ACT), activated partial thromboplastin time (APTT) or postoperative bleeding into chest drains. The median number of transfused units of Uniplas® was 3, with a range of 1–23, while the median for Octaplas® was 2 with a range of 1–11. These differences were not significant. Thus, Uniplas® has a similar effect as Octaplas® in the treatment of bleeding in patients undergoing openheart surgery. Uniplas® can therefore substitute for Octaplas® and eliminate the risk of ABO-incompatible transfusions.

Effects of long intubation period on respiratory functions following open heart surgery.

The objective of the present study was to compare pre- and postoperative pulmonary function tests in adult patients who had intubation periods greater and less than 24 hours following elective open heart surgery. Group 1 consisted of 91 patients (18 females and 73 males) gr, whose intubation periods were more than 24 hours (mean: 8.1+/-18.6 hours); and group 2 75 patients (13 females and 62 males) who had intubation periods less than 24 hours (mean: 13.25+/-3.60 hours). The pulmonary function test measurements were obtained from a vitalograph before and after the operation (just before being discharged from the hospital), All patients underwent cardiopulmonary physiotherapy and a rehabilitation programme during their hospital stay. The patients were similar in height and weight. The duration of hospitalization of the patients who had a prolonged intubation period was 17.26+/-9.7 days, while that of the control group was 10.64+/-2.04 days (P<0.0001). When the preoperative pulmonary function test values of each patient were compared with the expected values, the percent values of forced expiratory volume for one second, flow velocity of the mid-forced expiration and forced expiratory flow which were achieved by group 2 were significantly high compared to those of group 1 (P=0.014, P= 0.03 and P<0.0001, respectively). However, the percent values of forced vital capacity were similar. When the percent variations of the differences between the pre- and postoperative pulmonary function test values of the groups were compared, all values except the flow velocity of the mid-forced expiration, and forced vital capacity, were found to be significantly lower statistically in the group having a prolonged intubation period. As a result, it was determined that the patients whose preoperative pulmonary function test values were poor, had longer intubation periods and similarly, they continued to be worse after the operation. We believe that it is advantageous to apply more intensive pulmonary rehabilitation for prolonged periods to these patients in the postoperative period.

A comparison of rocuronium and pancuronium in adult patients scheduled for 'fast-track' elective open heart surgery involving hypothermic cardiopulmonary bypass

The non-depolarising muscle relaxant (NDMR) pancuronium continues to be used for fast-track cardiac anaesthesia despite its declining popularity elsewhere. Its duration of action can be unpredictable and prolonged, leading to an increased incidence of residual neuromuscular block [1]. We examined whether pancuronium remains an appropriate NDMR for 'fast-track' patients and include comparison with rocuronium, which has been suggested as an alternative agent.

A comparison of rocuronium and pancuronium in adult patients scheduled for 'fast-track' elective open heart surgery involving hypothermic cardiopulmonary bypass

The non-depolarising muscle relaxant (NDMR) pancuronium continues to be used for fast-track cardiac anaesthesia despite its declining popularity elsewhere. Its duration of action can be unpredictable and prolonged, leading to an increased incidence of residual neuromuscular block [1]. We examined whether pancuronium remains an appropriate NDMR for 'fast-track' patients and include comparison with rocuronium, which has been suggested as an alternative agent.

Comparison of Cardiac Output Measured by Impedance Cardiography and Thermodilution in Open Heart Surgery

Background: Impedance Cardiography is a noninvasive and simple method of cardiac output determination. The purpose of this study was to compare an impedance device with the thermodilution method during the intraoperative period in patients undergoing open heart surgery. Methods: The study was undertaken in 12 patients undergoing elective open heart surgery without a shunt. When abnormal impedance signals were obtained, the patients were not included in the analysis. Stroke volume was calculated according to the formula of Bernstein. Cardiac output was measured simultaneously by the impedance cardiograph and thermodilution method. We obtained 41-paired measurements during the surgical procedure. The method described by Bland and Altman and linear regression analysis were used for comparison. Results: The correlation coefficient between the two methods was r = 0.36 (P

FK506 does not affect cardiac contractility and adrenergic response in vitro

FK506 (tacrolimus) is a new immunosuppressant being used in cardiac allograft transplantation. While cyclosporine A has been shown to exert an acute negative inotropic effect on isolated heart muscle preparations, little is known of the inotropic influence of FK506. The Ca 2+ release channel of human skeletal muscle and cardiac muscle is associated with FK506 binding proteins (FKBP), FKBP12 and FKBP12.6, respectively. FKBPs can be dissociated by treatment with FK506. As a consequence of FK506 exposure, isolated skeletal muscle and cardiac muscle ryanodine receptors show altered gating characteristics. Therefore, we analyzed the direct inotropic effect of FK506 exposure to isolated, intact heart muscle preparations from the human and rabbits. Experiments were performed on isolated, electrically stimulated right atrial auricular muscle strips obtained from human myocardium during elective open heart surgery and on intact right ventricular trabeculae from rabbit hearts. The human preparations were exposed to concentrations of 8×10 −9, 8×10 −8 and 8×10 −6 M FK506 followed by a cumulative dose–response curve with isoprenaline as a non-selective β-adrenoceptor agonist. Our data suggest that FK506 does not exert any positive or negative inotropic effect in either human or rabbit myocardium.

Clinical Impact of Histidine-Ketoglutarate-Tryptophan (HTK) Cardioplegic Solution on the Perioperative Period in Open Heart Surgery Patients

Background Ischemia-reperfusion injury during open heart surgery related to unsuccessful myocardial protection may increase morbidity or mortality. We analyze the clinical outcome after cardiac surgery with a cardioplegic solution based on intracellular components added with histidine-ketoglutarate-tryptophan. Methods Thirty patients programmed for elective open heart surgery were randomized into two groups. In group I ( n = 15), myocardial protection was carried out with Bretschenider solution (HTK), and in group II ( n = 15) with conventional crystalloid cardioplegia. The incidence of arrhythmias, inotropic support requirement, and length-of-stay in the intensive care unit were evaluated. Results During reperfusion, there was no difference in incidence of arrhythmias; however, in the postoperative period group I had a lower incidence of arrhythmias ( p = 0.001). Inotropic support ( p = 0.003) and length-of-stay in the intensive care unit ( p = 0.037) were lower in group I. There were no deaths in either group. Conclusions It was concluded that myocardial protection with Bretschneider solution effectively decreases incidence of arrhythmias, inotropic support, and length-of-stay in the intensive care unit.

Reducing stress responses in the pre-bypass phase of open heart surgery in infants and young children: a comparison of different fentanyl doses

High-dose opioids are advocated for paediatric cardiac surgery to suppress stress responses but they can produce unwanted side effects. There are no data on the dose-dependent effects of opioids on the stress response on which to base rational opioid administration. We conducted a dose ranging study on 40 children less than 4 yr undergoing elective open heart surgery using one of five fentanyl doses: 2, 25, 50, 100 or 150 micrograms kg-1 before surgery. The standardized anaesthetic also included pancuronium and isoflurane. Blood samples were taken at induction, before incision, after sternotomy, immediately before, and at the end of cardiopulmonary bypass. Patients in the 2 micrograms kg-1 group had significant rises in prebypass glucose (P < 0.01), pre- and post-bypass cortisol (P < 0.01), and pre- and post-bypass norepinephrine (P < 0.01). No significant rise occurred in glucose, cortisol and catecholamines in any of the higher dosage groups. Patients in the 2 micrograms kg-1 group had significantly higher mean systolic blood pressure (P < 0.02) and heart rate (P < 0.04). A balanced anaesthetic containing fentanyl 25-50 micrograms kg-1 is sufficient to obtund haemodynamic and stress responses to the pre-bypass phase of surgery. Higher doses of fentanyl (100 and 150 micrograms kg-1) offer little advantage over 50 micrograms kg-1, and can necessitate intervention to prevent hypotension.

Patients with poor preoperative ejection fraction have a higher plasma response of adrenomedullin in response to open heart surgery.

Adrenomedullin (AM) is a potent vasodilator peptide. Plasma AM levels are increased in heart diseases and in sepsis. Heart surgery under cardiopulmonary bypass (CPB) induces a systemic inflammatory response. We measured plasma AM, cAMP (the second messenger of AM), C-reactive protein (CRP) and haemodynamic parameters in 29 patients undergoing elective open heart surgery, before, during and after anaesthesia and CPB as well as on the first morning after surgery. Basal AM levels were higher than normal and correlated with systolic pulmonary pressure and pulmonary capillary pressure, but not with other haemodynamic parameters. AM increased during CPB and remained elevated 24 h after the start of surgery. Plasma cAMP increased only at the end of CPB. CRP was increased only in the last sample. At the end of CPB and at the end of surgery AM levels were higher in patients with basal ejection fraction<40% compared with those with ejection fraction >60% [456+/-386 vs 252+/-343 (P<0.03) and 832+/-781 vs 391+/-356 pg/ml (P<0.05), respectively]. We conclude that AM, as inflammation-related cytokines, increases during and after CPB, that cAMP response is unrelated to AM and that AM response is higher in those patients with worse basal ejection fraction.

Time-course of impairment of respiratory mechanics after cardiac surgery and cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) is associated with abnormalities of lung function characterized by an increase in static elastance of the respiratory system. We examined the following: a) the effects of CPB on the total inspiratory volume-pressure (V-P) relationship of the respiratory system; b) the relative contribution of the chest wall and lung to the impairment of respiratory system mechanics; and c) the time-course of such impairment. Prospective, interventional study. Surgical and medical intensive care units in a teaching hospital. Eight adult patients scheduled for elective open heart surgery to correct valvular dysfunction. V-P curves (interrupter technique) of the respiratory system were partitioned between the chest wall and lung by measurements of esophageal pressure. Measurements were obtained before sternotomy (control), immediately after, 4 hrs after, and 7 hrs after separation from CPB. Control V-P relationships of the respiratory system and lung showed lower inflection points (Pflex) at pressure values of 5.9+/-2.3 and 4.3+/-2.5 cm H2O, respectively. Immediately after and 4 hrs after separation from CPB, both curves had sigmoid shapes because of lower Pflex and formation of upper inflection (UIP) points. The pressures corresponding to the Pflex increased significantly (p < .001) by 56%+/-3% and 78%+/-4%, whereas the UIP corresponded to a pressure value of 42.34+/-8.5 and 35.6+/-7.8 cm H2O in the respiratory system and lung, respectively. A linear V-P relationship of the chest wall was observed during the control condition and after separation from CPB. Four hours later, no further increases in the pressure values corresponding to Pflex were observed on the inspiratory V-P curves of the respiratory system and lung, whereas the UIP occurred at a pressure of 35.6+/-9.1 and 29.7+/-8.4 cm H2O, respectively. A UIP was present on the V-P curve of the chest wall at a volume of 0.77+/-0.02 L. Seven hours after separation from CPB, the inspiratory V-P curves of the respiratory system, chest wall, and lung returned to normal. Sternotomy and CPB produced immediate changes in lung mechanics. Chest wall mechanics were affected only 4 hrs after sternotomy. Seven hours after disconnection from CPB, all mechanics had returned to normal.

Are in-vitro platelet function tests useful in predicting blood loss following open heart surgery?

We investigated the suitability of two commercially available in-vitro bleeding tests (IVBT), the PFA-100 and the Hepcon HMS, to predict blood loss following operations with extracorporeal circulation (ECC) and compared them with conventional coagulation studies. In 40 patients subjected to elective open heart surgery with ECC a blood sample was taken before and after ECC to measure platelet count, prothrombin time, aPTT, D-dimers, fibrinogen, and PFA-100 and Hepcon HMS data. The postoperative blood loss was recorded hourly until removal of drains. A significant correlation was found between total blood loss (250-1750 ml) and the preoperative PFA-100 (r = 0.41, p = 0.022), the preoperative platelet count (r = -0.42, p = 0.007), the preoperative D-dimer concentration in the plasma (r = 0.41, p = 0.01), and duration of ECC (r = 0.35, p = 0.044). There was no significant correlation between blood loss and the Hepcon HMS system. Although a significant correlation was found between blood loss and the PFA-100 IVBT, the practical value of these tests in the clinical situation is limited due to a great variability in individual results.