Changes in plasma LDL and HDL composition in patients undergoing cardiac surgery.

Changes of lipoprotein composition have been mainly reported in conditions of sepsis. This study characterized compositional changes in LDL and HDL during the acute phase response following cardiac surgery with cardiopulmonary bypass. Twenty-one patients undergoing cardiac surgery were included in this study. Blood samples were drawn before operation and on day 2 post-surgery. In parallel to plasma lipids and antioxidant status, lipoproteins were analyzed for lipid, apolipoprotein (apo), hydroperoxide and alpha-tocopherol content. Beyond decreases in lipid concentrations and antioxidant defenses, cardiac surgery induced substantial modifications in plasma lipoproteins. ApoB decrease in LDL fraction (-46%; P < 0.0001) reflected a marked reduction in the circulating particle number. LDL cholesteryl ester content relative to apoB concentration remained unchanged post-surgery while triglyceride (+113%; P < 0.001), free cholesterol (+22%; P < 0.05) and phospholipid (+23%; P < 0.025) were raised relative to apoB indicating increased particle size. In HDL, an abrupt rise of apoSAA (P < 0.05) was observed together with a decrease of apoA1 (-22%; P < 0.005). Cholesteryl ester content in HDL fraction decreased in parallel to apoA1 concentration while triglycerides, free cholesterol and phospholipids increased relative to apoA1. In contrast to unchanged alpha-tocopherol content, hydroperoxide content was increased in LDL and HDL. By comparison to sepsis, cardiac surgery induces a comparable reduction in circulating LDL but a more limited decrease in HDL particles. Furthermore, in contrast, cardiac surgery induces an increase in polar and non-polar lipids, as well as of particle size in both LDL and HDL.

Haemodynamics during remifentanil induction by high plasma or effect-site target controlled infusion.

BACKGROUND: During total intravenous anaesthesia, the target controlled infusion concentration of remifentanil can be achieved either in limiting maximum plasma concentration (Cp) to the effect site target concentration which corresponds to a plasma TCI technique (pTCI) or as fast as possible to achieve the effect-site target without limiting Cp (eTCI). The aim of this study was to compare the haemodynamic effects of remifentanil pTCI and eTCI during induction of anaesthesia in ASA III patients undergoing cardiac surgery. METHODS: 28 ASA III patients, scheduled for cardiac surgery, were randomized in two groups: Group pTCI received remifentanil to achieve an effect-site target of 15 ng ml(-1) by limiting Cp to 15 ng ml(-1) and group eTCI received remifentanil to achieve an effect-site target of 15 ng ml(-1) without limiting remifentanil Cp. Before induction, all patients received 30 microg kg(-1) of midazolam intravenously and 2 ml kg(-1) of a gelatin solution. Heart rate, invasive arterial pressure and bispectral index were continuously measured. Differences from baseline values were compared between the two groups using a Mann-Whitney U test. Baseline population characteristics were compared using an analysis of variance. RESULTS: There were no significant differences in haemodynamic parameters between the two groups. In the group pTCI final effect-site concentration was reached in 7.3 +/- 1.4 minutes and in the group eTCI in 2.2 +/- 0.2 minutes (p < 0.05). CONCLUSION: In ASA III patients scheduled for elective cardiac surgery, remifentanil eTCI can be preferred to remifentanil pTCI for induction because of its shorter onset with the same haemodynamic stability.

Tocopherol in lipoproteins and blood cells after cardiac surgery.

Cardiac surgery was associated with a marked reduction in circulating LDL and HDL particles, which in turn largely affectd alpha-toc transport. alpha-toc was decreased in WBCs but not in PLTs and RBCs. An increased hydroperoxide content was observed in LDL and possibly in HDL after cardiac surgery.

[The anesthesiology-recovery department]. / Le Service d'Anesthésiologie Réanimation.

The Department of Anesthesiology and Reanimation is organised in units with clinical activities, which include the pre-operative care of patients, anesthesiological care and immediate post-operative supervision. Two post-operative treatment rooms also form part of the department. The main fields of research of the various units result from collaborations with other departments of Hôpital Erasme, in particular with regard to the development of advanced techniques or fit within the confines of the speciality.

Patent foramen ovale and implantable cardioverter defibrillator.

A case of patent foramen ovale opening was observed concomitantly to a defibrillation threshold determination in the setting of an internal cardioverter defibrillator implantation. The subsequent transient right-to-left shunt was confirmed by a peroperative transoesophageal echocontrast study. The underlying mechanism of this incident may be related to a transient reversal of the interatrial gradient, due to the pre-existence of pulmonary hypertension and tricuspid regurgitation, associated with ongoing mechanical ventilation and modifications of intracardiac pressures regimen secondary to the succeeding ventricular tachyarrhythmia and defibrillation. Paradoxical embolism can be an aetiology for neurologic injury during internal cardioverter defibrillator implantation.

Doppler-derived left ventricular rate of pressure rise and inotropic requirements during mitral valve surgery.

BACKGROUND: The estimation of left ventricular (LV) contractility is difficult in the presence of significant mitral regurgitation (MR). Prediction of LV performance after MR repair is even more problematic. The intraoperative Doppler-derived LV rate of pressure rise (LV delta P/delta t) analyzed before cardiopulmonary bypass (CPB) was presumed to be a useful predictive parameter for LV performance. Therefore, its relation to perioperative inotropic requirements (PIR) necessary for separation from CPB after surgical MR repair was investigated. METHODS: Twenty-eight patients scheduled for surgical MR repair fulfilled the selection criteria. Pre-CPB LV delta P/delta t, pre-CPB echocardiographic LV fractional area change (LV FAC), and pre-CPB thermodilution-derived cardiac index (CI) were recorded. After MR repair, separation from CPB was performed with regard to standardized guidelines. PIR during the first 60 minutes following separation were recorded. RESULTS: Pre-CPB LV delta P/delta t could be assessed in 22 patients. Pre-CPB LV delta P/delta t was 882 +/- 450 mmHg/sec, pre-CPB LV FAC was 49% +/- 9%, and pre-CPB CI was 2.0 +/- 0.2 L/kg/min. Pre-CPB LV delta P/delta t was significantly correlated with pre-CPB LV FAC (r = 0.56), and with pre-CPB CI (r = 0.72). Inotropic support was necessary in 16 patients (73%), and was best predicted by the pre-CPB LV delta P/delta t, by means of logistic regression (p = 0.026). CONCLUSIONS: Doppler-derived LV delta P/delta t was assessable in most patients with severe chronic MR, and was the best intraoperative predictive parameter of post-CPB inotropic requirements after surgical MR repair.

Hemodynamic benefit of optimizing atrioventricular delay after cardiopulmonary bypass.

BACKGROUND: Shortening of atrioventricular delay (AVD) by sequential cardiac pacing has been proposed to improve hemodynamics in patients with end-stage heart failure. In addition, optimization of prolonged AVD may be associated with a decrease of presystolic mitral insufficiency. The aim of this study was to explore the incidence of prolonged AVD during the early postcardiopulmonary bypass (CPB) period and to evaluate the hemodynamic benefit of its shortening by using sequential cardiac pacing. METHODS: Fifty consecutive patients scheduled for coronary artery bypass grafting were prospectively screened. AVD was measured immediately after separation from CPB. Patients presenting with AVD greater than or equal to 200 ms entered the study. Sequential cardiac pacing was introduced with programmed AVD starting at 80 ms and randomly increased by steps of 20 ms until resumption of native anterograde atrioventricular node conduction. Cardiac index (CI) was derived from transesophageal echocardiographic data during each step of this procedure. RESULTS: Nineteen patients were included. Median native AVD was 220 ms. Median optimal AVD was 140 ms. Mean native CI (CI-nat) was 2.59 +/- 0.42 L/min/m2. Mean optimal CI (CI-opt) was 3.12 +/- 0.45 L/min/m2. CI-opt/CI-nat was 1.20 +/- 0.07. CI-opt/CI-nat was significantly inversely correlated with preoperative left ventricular ejection fraction (r = -0.83). CONCLUSIONS: Prolonged AVD is a common occurrence after CPB. Its artificial shortening by sequential cardiac pacing is always associated with a significant increase of CI. The magnitude of this hemodynamic improvement is inversely correlated with preoperative left ventricular ejection fraction.

Persistent left superior vena cava: transoesophageal echocardiographic findings and surgical strategies.

Two cases of casual discovery of persistent left superior vena cava during cardiac surgery are reported. Diagnoses were suspected at the time of peroperative transoesophageal echocardiography in the first case, and of preoperative fluoroscopy during a Swan-Ganz catheter insertion procedure in the second case. For both patients, a peroperative echo contrast study permitted to confirm the anomaly before initialization of cardiopulmonary bypass. Embryology, echocardiographic findings and surgical management, including cardioplegia delivering and left upper venous system drainage, are reviewed.

Propofol-alfentanil versus fentanyl-midazolam in coronary artery surgery.

OBJECTIVE: To compare intraoperative hemodynamics profiles and recovery characteristics of propofol-alfentanil with fentanyl-midazolam anesthesia in elective coronary artery surgery. DESIGN: Prospective, randomized study. SETTING: University hospital. PARTICIPANTS: Fifty patients with impaired or good left ventricular function. INTERVENTIONS: In group 1, (n = 25) anesthesia was induced with an infusion of propofol, 3 to 4 mg/kg/h, alfentanil, 500 micrograms, and pancuronium 0.1 mg/kg, and maintained with propofol, 3 to 6 mg/kg/h (variable rate), and alfentanil infusions, 30 micrograms/kg/h (fixed rate). Additional boluses of alfentanil, 1 mg, were administered before noxious stimuli; group 2 (n = 25) received a loading dose of fentanyl, 25 micrograms/kg, midazolam, 1.5 to 3 mg, and pancuronium, 0.1 mg/kg for induction, followed by an infusion of fentanyl, 7 micrograms/kg/h, for maintenance. Additional boluses of midazolam (1.5 to 3 mg) and fentanyl (250 micrograms) were administered before noxious stimuli. MEASUREMENTS AND MAIN RESULTS. Cardiovascular parameters at eight intraoperative time points as well as time to extubation, morphine consumption, and pain scores were recorded. Induction of anesthesia was associated in both groups with a small but significant decrease in mean arterial pressure (1: 15 mmHg (15%); 2: 8 mmHg (8%) with significant decreases in cardiac index (1: 8%; 2: 8%) and left ventricular stroke work index (1: 24%; 2: 21%). Throughout surgery, hemodynamic profiles were comparable between groups except after intubation when the MAP was significantly lower in group 1 (75 +/- 12 mmHg) than in group 2 (89 +/- 17 mmHg). Group 1 required less inotropic support. Extubation was performed faster in group 1 (7.6 h) than in group 2 (18.0 h). Morphine requirements and pain scores were comparable between groups. CONCLUSIONS: Propofol-alfentanil anesthesia provides good intraoperative hemodynamics and allows early extubation after coronary artery surgery.