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Abstract

266 CABG = coronary artery bypass grafting; CI = cardiac index; CPB = cardiopulmonary bypass; HR = heart rate; ICG = indocyanine green; ICU = intensive care unit; IMA = internal mammary artery; LCOS = low cardiac output syndrome; LVEF = left ventricular ejection fraction; MAP = mean arterial pressure; NO = nitric oxide; PDI = phosphodiesterase inhibitor; pHi = intramucosal pH; PVR = pulmonary vascular resistance; SVR = systemic vascular resistance; SVI = stroke volume index. Critical Care June 2005 Vol 9 No 3 Gillies et al. AbstractMany adult patients require temporary inotropic support after cardiac surgery. We reviewed the literature systematically to establish, present and classify the evidence regarding choice of inotropic drugs. The available evidence, while limited in quality and scope, supports the following observations; although all β-agonists can increase cardiac output, the best studied β-agonist and the one with the most favourable side-effect profile appears to be dobutamine. Dobutamine and phosphodiesterase inhibitors (PDIs) are efficacious inotropic drugs for management of the low cardiac output syndrome. Dobutamine is associated with a greater incidence of tachycardia and tachyarrhythmias, whereas PDIs often require the administration of vasoconstrictors. Other catecholamines have no clear advantages over dobutamine. PDIs increase the likelihood of successful weaning from cardiopulmonary bypass as compared with placebo. There is insufficient evidence that inotropic drugs should be selected for their effects on regional perfusion. PDIs also increase flow through arterial grafts, reduce mean pulmonary artery pressure and improve right heart performance in pulmonary hypertension. Insufficient data exist to allow selection of a specific inotropic agent in preference over another in adult cardiac surgery patients. Multicentre randomized controlled trials focusing on clinical rather than physiological outcomes are needed.

Liver function predicts survival in patients undergoing extracorporeal membrane oxygenation following cardiovascular surgery

“…The present study population was exposed to severe hemodynamic fluctuations due to low cardiac output on one hand [ 34 , 35 ] and ECMO support itself on the other [ 36 – 38 ]. ECMO therapy may affect liver perfusion due to changes in pump flow and the lack of pulsatility, rapid changes of vasopressors doses after ECMO initiation, and air or thrombus embolization [ 36 – 38 ].…”

Mild metabolic acidosis impairs the β-adrenergic response in isolated human failing myocardium

“…Because of cardiac ischemia, myocardial dysfunction induced by cardioplegia, reperfusion injury, the presence of nonrepaired preexisting cardiac disease, and the activation of coagulation cascades and inflammation, a pharmacologic support can be necessary [52]. It is not unusual for these patients to develop a systemic inflammatory response syndrome (SIRS) that may lead to sepsis [25-27].…”

Hyperkalemic cardioplegia for adult and pediatric surgery: end of an era?

“…The phenomenon was first described experimentally in 1975 by Heyndrickx and colleagues, who reported an abnormal, depressed ventricular function after regional ischemia in dogs despite normal return of coronary blood flow and ECG waveform (Heyndrickx et al, 1975). It is manifest as a decrease in cardiac output typically lasting 2–4 h post-operatively (Gillies et al, 2005), and can persist for longer periods without apparent signs of infarction or other serum injury markers (Troponins or CKMB) (Kloner and Jennings, 2001). Stunning occurs in about 10% of adults following cardiac surgery (Weisel, 1993; Vaage and Valen, 1993; Mangano, 1995; Spinale, 1999; Flack et al, 2000; Chang et al, 2002; Anselmi et al, 2004) and in 10–15% of pediatric patients (Parr et al, 1975; Booker, 1998; Ravishankar et al, 2003).…”