Philippe Baele

Amrinone in the management of low cardiac output after open heart surgery

Hemodynamic effects of amrinone were studied in 2 groups of patients after open heart surgery. Group I consisted of 10 patients with moderate heart failure. In the absence of inotropic agents, their mean cardiac index (CI) was 2.02 +/- 0.41 liters/min/m2 and mean pulmonary capillary wedge pressure (PCWP) 19 +/- 3 mm Hg. Amrinone was administered 24 hours postoperatively by bolus injection (2 mg/kg) and by 12-hour infusions (20 micrograms/kg/min). Hemodynamic data and plasma concentrations were obtained 10 and 20 minutes after the bolus injection and at 1, 4, 8 and 12 hours during infusion. Significant beneficial changes were noted in CI, PCWP, right atrial pressure, systemic vascular resistance and pulmonary vascular resistance. Group II consisted of 5 patients in severe cardiogenic shock (mean CI 1.97 +/- 0.3 liters/min/m2, mean PCWP 28 +/- 8 mm Hg) despite adrenergic agonists in all patients and intraaortic counterpulsation in 2. After these measures, amrinone was given intravenously for 36 to 72 hours as additional inotropic support. Significant improvement was observed in CI, PCWP, right atrial pressure, systemic vascular resistance and pulmonary vascular resistance. Four patients in this group were discharged; 1 patient died after 5 days in acute renal failure and coma grade IV. No serious adverse effects of amrinone were observed in any group II patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Fibrinogen concentration significantly decreases after on-pump versus off-pump coronary artery bypass surgery: a systematic point-of-care ROTEM analysis

OBJECTIVES Studies have emphasized the importance of normal fibrinogen concentrations in surgical patients. The primary hypothesis of this study was that fibrinogen levels significantly decrease in on-pump coronary artery bypass graft (CABG) surgery versus off-pump coronary artery bypass graft (OPCAB) surgery. The second objective was to show that ROTEM (TEM International, GmbH, Munich, Germany) rapidly detects these abnormalities compared with standard tests. DESIGN A prospective, nonrandomized study. SETTING A university hospital. PARTICIPANTS Forty-two and 62 patients in the CABG and OPCAB groups, respectively, undergoing first-time bypass surgery were included. INTERVENTIONS CABG versus OPCAB surgery. MEASUREMENTS AND MAIN RESULTS Routine coagulation tests and ROTEM values were measured before anesthesia (T0), after the first dose of heparin (T1), after protamine (T2), upon intensive care unit arrival (T3), and 4 hours postoperatively (T4). The outcome measures were followed until 4 hours postoperatively. Fibrinogen concentrations were significantly lower in the CABG versus the OPCAB group at T2 (170 ± 44 v 243 ± 73 mg/dL, p < 0.001) and T3 (179 ± 42 v 232 ± 68 mg/dL, p < 0.001). This was confirmed by significantly lower FIBTEM maximal clot firmness values at T2 (9 ± 4 v 14 ± 5 mm, p < 0.001) and T3 (9 ± 4 v 13 ± 6 mm, p < 0.001). In the CABG group, patients received significantly more transfusions of all blood products except fresh frozen plasma. CONCLUSIONS Fibrinogen concentration significantly decreases after cardiopulmonary bypass. ROTEM helps in its fast detection.

Anaphylactic shock in a beta-blocked child: usefulness of isoproterenol.

Like adults, children taking beta‐blockers are at risk for serious hemodynamic instability in case of anaphylaxis. We report a case of severe bradycardia associated with anaphylactic shock after aprotinin in a beta‐blocked child, which was resistant to intravenous epinephrine and vascular filling but was treated successfully with isoproterenol.

Concentration of transfusion resources on a few pathologies and a few patients: analysis of the comprehensive in-hospital patient database.

BACKGROUND: Blood is a sparse commodity. Transfusion needs increase while the number of donors decreases. These constraints incite Belgian authorities to pay more attention to transfusion financing. This implies pathologic knowledge of the epidemiology of in‐hospital transfusion and the consumption of blood products.

Le suivi par potentiels évoqués somesthésiques des patients adultes subissant un arrêt circulatoire sous hypothermie profonde.

The surgical repair of ascending aorta aneurysms can only be carried out under total circulatory arrest, and is consequently to be performed under deep hypothermia, in order to adequately decrease the metabolic requirements of the brain. However, the optimal temperature to be reached is poorly known. SEPs to median nerve stimulation were recorded in 21 operations performed in 20 patients undergoing profound hypothermia. The latencies of all SEP components increase to 21 degrees C. Waves N20 and P14 disappear at mean naso-pharyngeal temperatures of 20 degrees C and 17 degrees C, respectively, although a wide inter-individual variability was observed. We suggest to use the P14 disappearance as the criterion to perform the circulatory arrest: in fact, all surviving patients in whom this criterion was fulfilled recovered without any detectable neurological sequellae, while three patients in whom brain activities disappeared independently on body temperature presented with neurological sequellae. Moreover, particularly if patients presenting with ischemia-induced disappearance of Erbs point activities were excluded, we found a significant correlation between the duration of the circulatory arrest and the delay of N20 and P14 reappearance on rewarming. This confirms the importance of sufficient hypothermia, on the one hand; and on the other hand, our findings imply that, even if SEP monitoring considerably decreases the risk of neurological sequellae associated with these operations, the duration of the circulatory arrest should be reduced as far as possible.

Clinical use and bacteriological studies of catheter contamination sleeves

A system combining a valved introducer sheath and a plastic protective sleeve enabling repositioning of pulmonary artery catheters was tested in 73 cardiac surgical patients. It was used for a mean time of 70.3 h and allowed for improved hemodynamic monitoring. A 12 percent incidence of valve contamination was found and makes the safety of the device questionable.

An increase in endogenous erythropoietin concentrations has no cardioprotective effects in patients undergoing coronary artery bypass graft surgery

OBJECTIVE Preliminary data showed an increase in endogenous erythropoietin (EPO) concentrations after acute normovolemic hemodilution (ANH) in patients undergoing coronary artery bypass graft (CABG) surgery. Numerous studies have shown the organ protective properties of EPO. The aim of this study was to investigate the cardioprotective effects of these increased EPO concentrations that resulted from ANH during cardiac surgery. DESIGN A prospective, randomized, blind study. SETTING A university hospital. PARTICIPANTS A total of 93 patients undergoing isolated CABG surgery with or without cardiopulmonary bypass (CPB). INTERVENTIONS Subjects with CPB were randomized into the control (C) or ANH group. Those in the off-pump coronary artery bypass group underwent no treatment. In the ANH group, a precalculated amount of blood was withdrawn and replaced by colloids after the induction of anesthesia. MEASUREMENTS AND MAIN RESULTS Hemodynamic parameters were recorded intra- and postoperatively. Troponin concentrations were measured as a routine parameter postoperatively. Upon intensive care unit arrival, the EPO levels were higher in the ANH group than in the C group. There was no significant difference between the troponin values of the C and the ANH groups at 4 hours postoperatively. CONCLUSIONS In patients undergoing CABG surgery on CPB, an increase in endogenous EPO concentrations in the physiologic range has no cardioprotective effects.

Detection by NeuroSENSE(®) Cerebral Monitor of Two Major Neurologic Events During Cardiac Surgery

From the Departments of *Anesthesiology, †Cardiac Intensive Care Unit, ‡Neurology; and §Cardiac Surgery, Université Catholique de Louvain, Cliniques Universitaires Saint Luc, Brussels, Belgium. Address reprint requests to Mona Momeni, MD, PhD, Université Catholique de Louvain, Cliniques Universitaires Saint Luc, Department of Anesthesiology, Avenue Hippocrate 10/1821 1200, Brussels, Belgium. E-mail: mona.momeni@uclouvain.be

The Effects of Halothane, Enflurane, and Isoflurane on the Length—Tension Relation of the Isolated Ventricular Papillary Muscle of the Ferret

The effects of halothane, enflurane, and isoflurane on the length-tension relation were investigated in papillary muscles of the right ventricle of adult male ferrets at 30 degrees C. Isometric twitch contractions were obtained at lengths ranging from the shortest length yielding the greatest active force development under isometric conditions (Lmax) to 86% of Lmax, in two consecutive protocols: first in [Ca2+]o ranging from 0.45 to 2.25 mM, and then in [Ca2+]o 2.25 mM before, during, and after exposure to incremental concentrations of halothane (n = 9 muscles), enflurane (n = 9 muscles), and isoflurane (n = 9 muscles), each in steps of 0.25 MAC to total concentrations up to and including 1.5 MAC. Each of the three anesthetics caused a concentration-dependent decrease in developed force. The relative extent of the negative inotropic effect was not different at various muscle lengths. Because myofibrillar Ca2+ responsiveness (Ca2(+)-affinity of troponin C) decreases at shorter muscle lengths, the results suggest that an alteration in myofibrillar Ca2+ responsiveness by volatile anesthetics is minor relative to the anesthetic-induced decreased intracellular Ca2+ availability in ventricular myocardium.

Transcatheter aortic valve implantation (TAVI): short- and long-term outcomes with respect to the type of procedure and the anaesthetic management

Results and discussion: 44patients were classified into two groups according to 75% quartile of RT(85.5sec): ER (RT < 85.5 sec, n=33) and DR (RT> 85.5sec, n=11). The DR group had significantly smaller body surface area (p< 0.05) and lef t ventricular diameter (p< 0.05), and more complicated with intraventricular out flow obstruction, and lower SvO2 immediately before RP. The multivariate logistic regression model identified SvO2 as an independent predictor of the delayed recovery af ter RP (OR 0.767, CI 0.4830.928). During TAVI, maintaining systemic oxygen supply-demand balance during surgery may overcome the preoperative disadvantageous factors.