Martin Goenen

Effects of conventional physiotherapy, continuous positive airway pressure and non‐invasive ventilatory support with bilevel positive airway pressure after coronary artery bypass grafting

Background: Coronary artery bypass graft (CABG) surgery with the use of mammary arteries is associated with severe alteration of lung function parameters. The purpose of the present study was to compare the effect on lung function tests of conventional physiotherapy using incentive spirometry (IS) with non‐invasive ventilation on continuous positive airway pressure (CPAP) and with non‐invasive ventilation on bilevel positive airway pressure (BiPAP or NIV‐2P).

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)

Cardiac troponin I as an early marker of myocardial damage after coronary bypass surgery

STUDY OBJECTIVE To evaluate the performance of cardiac specific markers, cardiac troponin I (cTnI) and CK-MB by mass assay (CK-MB mass), for the early diagnosis of myocardial ischemia and/or infarction after coronary bypass surgery. METHODS Prospective clinical, electrocardiograpic and biologic follow-up of 117 patients undergoing isolated coronary surgery with the use of intermittent anterograde normothermic blood cardioplegia. Blood samples for biochemical analysis were drawn before surgery (T0) and at 2 (T1), 6 (T2), 10 (T3) and 20 h (T4) after aortic cross-clamp release. Without knowledge of the biochemical data, patients were classified according to the electrocardiographic evolution into two groups: group 1, uneventful recovery and group 2, evidence of ischemia/infarction based on continuous ST-T segment monitoring and 12-lead ECG. RESULTS No patients had abnormal markers at T0. At T1, although both markers were elevated, no difference was noted between the two groups. At T2, 6 h after surgery, cTnI and CK-MB mass levels were significantly higher in group 2 than in group 1 (median = 17 microg/l, Interquartile Range (IR): 14.7-27.3 vs. 3.1 microg/l, IR 1.9-5.3 for cTnI and median 42.5 microg/l, IR: 27.1-95.7 vs. 13.6 microg/l, IR: 9.5-18.5 for CK-MB mass). A receiver operating characteristic (ROC) curve analysis shows that a cTnI value of 13.1 microg/ml has 100% specificity and 90% sensitivity to separate both groups, whereas a value of 33.2 microg/ml for CK-MB mass has a specificity of 100% and a sensitivity of 73%. At T3 and T4, the same difference was noted between the groups. cTnI values in all six patients with a Q-wave infarction were > or = 20 ng/ml, whereas only one of five patients with prolonged ischemia had cTnI level > 20 ng/ml. CONCLUSION As soon as 6 h postoperatively, cTnI and CK-MB by mass assay were able to separate those patients with an uneventful recovery from those with significant ischemia. This is particularly useful in frequent cases when the ECG is difficult to interpret.

Analysis of the accuracy of continuous thermodilution cardiac output .measurement Comparison with intermittent thermodilution and Fick cardiac output measurement

ObjectiveTo evaluate the accuracy of cardiac output measurement obtained by a new continuous thermodilution cardiac output (CCO) pulmonary artery catheter compared to intermittent thermodilution (TCO) and the direct Fick method.DesignProspective open trial.SettingUniversity hospital, intensive care unit.Patients23 patients (15 surgical, 8 non-surgical) were monitored with the Intellicath pulmonary catheter. Cardiac output was evaluated by the three methods every 4 to 6 h as long as the pulmonary artery catheter was necessary (8–96h).ResultsThe correlation coefficient between CCO and TCO was 0.92, no systematic bias was observed, and the relative error increased from 13.9% for a cardiac output of 1 l/min to 23.7% for an output of 10 l/min. When comparing CCO and Fick, the correlation coefficient was 0.89, no bias was detected, and the relative error increased from 20.4% for outputs of 2 l/min to 27.2% for outputs of 10 l/min.ConclusionsCCO provides clinically acceptable measurements. At high cardiac outputs, the difference with other methods increases and the results must be cautiously interpreted.

Effects of normothermia versus hypothermia on extravascular lung water and serum cytokines during cardiopulmonary bypass : A randomized, controlled trial

ObjectiveTo evaluate the influence of perfusion temperature on the systemic effects of cardiopulmonary bypass (CPB), including extravascular lung water index (EVLWI), and serum cytokines. DesignProspective, randomized, controlled study. SettingCardiothoracic intensive care unit of a university hospital. PatientsPatients undergoing elective coronary artery bypass grafting. InterventionsTwenty-one patients undergoing elective coronary artery bypass grafting were randomly assigned to receive either normothermic bypass (36°C, n = 8) with intermittent antegrade warm blood cardioplegia (IAWBC), or hypothermic (32°C, n = 13) CPB with cold crystalloid cardioplegia. Measurements and Main Results Mean arterial pressure, heart rate, cardiac output, systemic vascular resistance, mean pulmonary arterial pressure, and pulmonary vascular resistance were determined at baseline, i.e., after induction of anesthesia but before sternal opening (T−1), at arrival in the intensive care unit (T0), and 4 hrs (T4), 8 hrs (T8), and 24 hrs (T24) after surgery. EVLWI, intrathoracic blood volume index (ITBVI), and EVLW/ITBV ratio were obtained by using thermal dye dilution utilizing an arterial thermistor-tipped fiberoptic catheter and were recorded at T−1, T0, T4, T8, and T24. Serial blood samples for cytokine measurements were obtained at each hemodynamic measurement time point. Before, during, and after CPB, there were no differences in the conventional hemodynamic measurements between the groups. There were no changes in EVLWI up to T8 in either group. Furthermore, no change in the ratio EVLW/ITBW was observed between the groups at any time, further indicating the absence of a change in pulmonary permeability. Plasma levels of interleukin-6, tumor necrosis factor-&agr;, and interleukin-10 increased during and after CPB, independently of the perfusion temperature. ConclusionNormothermic CPB is not associated with additional inflammatory and related systemic adverse effects regarding cytokine production and EVLWI as compared with mild hypothermia. The potential temperature-dependent release of cytokines and subsequent inflammation has not been observed and normothermic CPB may be seen as a safe technique regarding this issue.

Randomized trial of intermittent antegrade warm blood versus cold crystalloid cardioplegia

BACKGROUND We performed a prospective randomized trial to compare intermittent antegrade warm blood cardioplegia with intermittent antegrade and retrograde cold crystalloid cardioplegia. METHODS Two hundred consecutive patients scheduled for isolated coronary bypass surgical procedures were randomized into two groups: Group 1 (n = 92) received cold crystalloid cardioplegia with moderate systemic hypothermia, group 2 (n = 108) received intermittent antegrade warm blood cardioplegia with systemic normothermia. Preoperative, intraoperative, and postoperative data were prospectively collected. RESULTS For the same median number of distal anastomoses, cardiopulmonary bypass duration and total ischemic arrest duration (57.3 +/- 20.5 versus 75 +/- 22.1 minutes, p < 0.001) were shorter in group 2 than in group 1. Apart from a higher right atrial pressure in the cold cardioplegia group, no hemodynamic difference was observed. Aspartate aminotransferase, creatine kinase-MB fraction, and cardiac troponin I levels were significantly lower in group 2 than in group 1. Outcome variables were not significantly different. CONCLUSIONS Intermittent antegrade warm blood cardioplegia results in less myocardial cell damage than cold crystalloid cardioplegia, as assessed by the release of cardiac-specific markers. This beneficial effect has only marginal clinical consequences. Normothermic bypass has no deleterious effect on end-organ function.

Treatment of Severe Verapamil Poisoning With Combined Amrinone-isoproterenol Therapy

Abstract Verapamil is a slow channel calcium entry blocker that exerts its pharmacologic effects by blocking calcium influx in arterial smooth muscle as well in conductible and contractile myocardial cells; it depresses sinus node function and the atrioventricular conduction system and causes arterial vasodilation. Overdose of verapamil has been reported 1,2 and usually responds to standard treatment, including calcium, catecholamines and ventricular pacing. We report a case of severe verapamil poisoning that did not respond to this therapy, but to a combination of amrinone and isoproterenol. Our therapeutic conception was based on experimental data that show that amrinone or milrinone, an amrinone-like compound, reversed the negative effects of verapamil on sinus node and atrioventricular conduction and its negative inotropic action. 3,4

Haemostasis disorders in open heart surgery with extracorporeal circulation. Importance of the platelet function and the heparin neutralization.

Abstract. The main haemostasis changes observed in a screening study performed in 40 patients who underwent an open heart surgery with extracorporeal circulation (ECC) are: a significant drop in platelet count from the onset of the ECC to the third postoperative day, a decrease of platelet retention and aggregation during ECC with an 8‐day persistently increased heparin‐neutralizing activity in plasma but not in serum, a moderate decrease of plasma factors I, II, VII‐X, X and XIII and a more important drop in factor V which disappears 24 h after ECC, a transitory increase of fibrinolysis during ECC and the lack of FDP elevation in the serum. These disorders require a very good neutralization of the heparin used during ECC. The ratio protamine/heparin can be established by a titration clotting time test. Protamine chloride seems to be more efficacious and to act more quickly than protamine sulfate for the neutralization. An overload in protamine can enhance the hemostatic, biological and clinical disorders. The preventive administration of platelet concentrate immediately after the heparin neutralization contributes to reduce the bleeding disorders related to the quantitative and qualitative platelet defects.

Hemodynamic effects and safety of sotalol in the prevention of supraventricular arrhythmias after coronary artery bypass surgery

Sotalol is a beta-adrenergic blocking drug with the additional property of lengthening the cardiac action potential. These electrophysiologic properties render the drug attractive for use in the prevention of postoperative supraventricular arrhythmias (SVA), and previous studies have suggested that it was indeed effective. The hemodynamic response to sotalol and its safety early after coronary artery bypass graft (CABG) surgery were therefore studied. Forty-two patients undergoing CABG were randomly assigned either to receive sotalol to prevent postoperative SVA (25 patients) or to serve as controls (17 patients). Sotalol was started 6 hours after surgery if patients had a cardiac index > 2.8 L/min/m2 with a pulmonary capillary wedge pressure < 15 mmHg, and if they had no contraindications to the use of beta-blockers. The drug was given as a loading infusion of 1 mg/kg over 2 hours, followed by a maintenance infusion of 0.15 mg/kg/h for 24 hours. Three hours later, patients received the first oral dose of 80 mg to be repeated every 8 or 12 hours. Adverse effects necessitating discontinuation of the drug (bradycardia < 50 beats/min, systolic blood pressure < 90 mmHg, or cardiac index < 2.2 L/min/m2) occurred in six patients (24%) and were mainly related to the loading infusion. The hemodynamic data for patients who completed the study were characterized by a significant fall of the cardiac index caused by a lower heart rate without significant change of the stroke volume index. The incidence of supraventricular arrhythmias was not significantly different in the two groups (3/19 in the sotalol group, 5/17 in the control group).(ABSTRACT TRUNCATED AT 250 WORDS)

Haemostasis Disorders in Open Heart Surgery with Extracorporeal Circulation

The main haemostasis changes observed in a screening study performed in 40 patients who underwent an open heart surgery with extracorporeal circulation (ECC) are : a significant drop in platelet count from the onset of the ECC to the third postoperative day, a decrease of platelet retention and aggregation during ECC with an 8-day persistently increased heparin-neutralizing activity in plasma but not in serum, a moderate decrease of plasma factors I, 11, VII-X, X and XI11 and a more important drop in factor V which disappears 24 h after ECC, a transitory increase of fibrinolysis during ECC and the lack of FDP elevation in the serum. These disorders require a very good neutralization of the heparin used during ECC. The ratio protamine/heparin can be established by a titration clotting time test. Protamine chloride seems to be more efficacious and to act more quickly than protamine sulfate for the neutralization. An overload in protamine can enhance the hemostatic, biological and clinical disorders. The preventive administration of platelet concentrate immediately after the heparin neutralization contributes to reduce the bleeding disorders related to the quantitative and qualitative platelet defects.