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Objectives: Coronary artery bypass grafting carried out in patients in cardiogenic shock or receiving cardiopulmonary resuscitation is an infrequently performed procedure, disrupting the normal process with a dramatic early risk. These circumstances mandate an analysis of the benefit, including the early identification of the late survivors., Methods: A consecutive series of patients undergoing coronary artery bypass grafting while in cardiogenic shock (n = 167) or while receiving cardiopulmonary resuscitation (n = 92) from August 1979 until August 2001 were studied by using time-related and multivariate methodologies and a common-closing-date follow-up methodology. The events leading to the preoperative condition were either a recent catheterization, recent coronary artery bypass grafting, recent percutaneous transluminal coronary angioplasty, an infarction at home, an infarction in the hospital, or an infarction after a recent infarction., Results: The 1- and 10-year survival was 59% +/- 6% and 47% +/- 7%, respectively. A normal hazard of late death was observed beyond the protracted early hazard. Multivariate analysis of survival identified an increased risk in the presence of additional comorbidity, treated diabetes, a lower pH at entry into the operating theater, and the presence of triple-vessel disease. The discriminatory power for hospital mortality of the predictive variables was low (receiving operator characteristic range, 0.56-0.69). The 30-day freedom from hospital discharge alive was 33% +/- 7%. The 8-day freedom from stroke was 94% +/- 3%, and 8-day freedom from mechanical univentricular or biventricular support was 87% +/- 5%. The 10-year freedom from cardiosurgical reintervention was 90% +/- 6%., Conclusions: Coronary artery bypass grafting in cardiogenic shock or during cardiopulmonary resuscitation has an extremely high and protracted periprocedural risk but is balanced by a satisfactory late survival. An early prediction of the hospital survivors is difficult.

Objectives: To compare the efficacy and safety of 3 doses of remifentanil as part of a total intravenous anesthesia technique with low-dose propofol in patients undergoing coronary artery bypass graft (CABG) surgery., Design: Multicenter, multinational, double-blind, randomized, dose comparison study., Setting: Nine hospitals in 5 countries., Participants: One hundred forty-one patients undergoing first-time elective CABG surgery., Interventions: Patients were premedicated with a short-acting oral benzodiazepine up to 2 h before surgery and randomized to receive continuous infusions of remifentanil 1.0 microg/kg/min (n = 45), 1.5 microg/kg/min (n = 44), or 2.0 microg/kg/min (n = 43), in combination with propofol 3 mg/kg/h. Nine patients received remifentanil 1.0 microg/kg/min on an open-label basis. Three different induction sequences (IS) were used. In IS 1 (n = 31), induction was started with remifentanil infusion followed 5 minutes later by propofol 0.5 mg/kg bolus and infusion at 3 mg/kg/h. Further bolus doses of propofol (10 mg) were given if loss of consciousness (LOC) was not attained after 5 minutes; pancuronium, 0.04 to 0.1 mg/kg, was administered at LOC. In IS 2 (n = 68), a priming dose of pancuronium, 0.015 mg/kg, was administered just before starting remifentanil. In IS 3 (n = 42), bolus doses of propofol, 10 mg every 10 seconds, were given until LOC, followed by pancuronium, 0.04 to 0.1 mg/kg, and the remifentanil and propofol infusions were started., Measurements and Main Results: There were no significant differences among the remifentanil dose groups with regard to the primary outcome measure, responses to sternotomy/sternal spread/maximal sternal spread. Responses to these stimuli were recorded in 11%, 11%, and 14% of patients in the remifentanil 1.0, 1.5, and 2.0 microg/kg/min dose groups, respectively. Similarly, there were no significant differences in the responses to other surgical stimuli. There was a high incidence of muscle rigidity when remifentanil was used to induce anesthesia., Conclusions: All 3 remifentanil dose regimens provided profound suppression of responses to surgical stimuli in the majority of patients. There was no apparent advantage in starting the remifentanil infusion rate above 1.0 microg/kg/min. Remifentanil is not suitable for use as a sole induction agent., (Copyright 2003, Elsevier Science (USA). All rights reserved.)

This multi-centre, parallel group, randomized, double-blind study compared the efficacy and safety of high-dose remifentanil administered by continuous infusion with an intermittent bolus fentanyl regimen, when given in combination with propofol for general anaesthesia in 321 patients undergoing elective coronary artery bypass graft surgery. A significantly lower proportion of the patients who received remifentanil had responses to maximal sternal spread (the primary efficacy endpoint) compared with those who received fentanyl (11% vs 52%; P<0.001). More patients who received remifentanil responded to tracheal intubation compared with those who received fentanyl (24% vs 9%; P<0.001). However, fewer patients who received remifentanil responded to sternal skin incision (11% vs 36%; P<0.001) and sternotomy (14% vs 60%; P <0.001). Median time to extubation was longer in the subjects who received remifentanil than for those who received fentanyl (5.1 vs 4.2 h; P=0.006). There were no statistically significant differences between the two groups in the times for transfer from intensive care unit or hospital discharge but time to extubation was significantly longer in the remifentanil group. Overall, the incidence of adverse events was similar but greater in the remifentanil group with respect to shivering (P<0.049) and hypertension (P<0.001). Significantly more drug-related adverse events were reported in the remifentanil group (P=0.016). There were no drug-related adverse cardiac outcomes and no deaths from cardiac causes before hospital discharge in either treatment group.

The lipoprotein(a) (Lp(a)) time course during and after coronary artery bypass grafting was examined in 20 caucasoid patients, in relation to the time courses of serum cholesterol and serum triglycerides. Samples were taken at eight different time points. Baseline geometric means (SD) for Lp(a), cholesterol and triglycerides were 115 (336) mg/L, 5.73 (1.10) mmol/L and 1.73 (1.21) mmol/L, respectively. Up to 10 min after cardiopulmonary bypass (CPB) and after correction for haemodilution, no observable effect of CPB on serum concentrations of Lp(a) could be demonstrated, whereas serum concentrations of total cholesterol and triglycerides showed a progressive and significant decline. Ten minutes after stopping CPB geometric means for cholesterol and triglyceride were 3.90 (0.82) and 0.90 (0.58) mmol/L, respectively. At the third post-operative day geometric Lp(a) and cholesterol means decreased to 62(90) mg/L and 2.97 (0.84) mmol/L, respectively, while triglycerides went up. It is concluded that Lp(a) levels remain constant during CPB, but mimic total cholesterol changes in the post-CABG period.

The cardioprotective effects of carnitine were tested in patients undergoing multiple aortocoronary bypass grafting. Intermittent aortic cross-clamping at 28 degrees C was used. Mean total cross-clamping time was 30 +/- 11 min. Patients were randomized into three groups: a control group receiving placebo (group 1), a group pretreated with 3 g carnitine intravenously before cardiopulmonary bypass (CPB) (group 2), and a group pretreated with 6 g carnitine intravenously (group 3). The markers of myocardial ischemia included levels of adenosine triphosphate, its catabolites, and creatine phosphate in transmural left ventricular biopsy specimens taken at the beginning and end of CPB, as well as hemodynamic recovery during weaning from CPB and for the next 24 h. The intravenous infusion of carnitine (3 or 6 g) had no hemodynamic effect. At the end of CPB myocardial tissue levels of adenosine triphosphate and creatine phosphate did not differ significantly among the groups (P greater than 0.05). Recovery of cardiac function during weaning from CPB and for the following 24 h was similar in all three groups (P greater than 0.05). It is concluded that pretreatment with carnitine neither facilitates weaning from cardiopulmonary bypass in patients undergoing aortocoronary bypass surgery nor favorably affects hemodynamic function during the next 24 h.

Midazolam and propofol were compared in an open randomized study for postoperative sedation during 12 h of mechanical ventilation in 40 patients following coronary artery bypass grafting. After an intravenous loading dose of midazolam (50 micrograms.kg-1) or propofol (500 micrograms.kg-1), a titrated continuous infusion was administered of midazolam (mean dose 38.1 micrograms.kg-1.h-1 (SEM 2.6)) or propofol (mean dose 909 micrograms.kg-1.h-1 (SEM 100)) together with a narcotic analgesic infusion. During mechanical ventilation midazolam and propofol produced a similar quality of sedation, but recovery (midazolam 66 min (SEM 16); propofol 24 min (SEM 7)) and weaning from the ventilator (midazolam 243 min (SEM 44); propofol 154 min (SEM 33)) where faster with propofol. In the 2 groups administration of an intravenous loading dose caused a significant decrease in mean arterial pressure but hemodynamic tolerance during maintenance infusion was good.

The new water-soluble benzodiazepine midazolam was compared in a randomized study to diazepam for postoperative sedation in fifty patients following aortocoronary bypass surgery with a sufentanil-anesthesia. Midazolam and diazepam were administered intravenously in repeated doses in conjunction with an opioid infusion (piritramide) from the end of surgery during a twelve-hour study period, patients being artificially ventilated. Midazolam scored better than diazepam for quality of sedation and cardiovascular stability during the period of mechanical ventilation and for respiration during the weaning period and after extubation, although no difference was found in weaning time from artificial ventilation and time of extubation. Hemodynamic tolerance for both drugs was good. The administration of a loading dose of midazolam 5 mg caused a slight, transient decrease in mean arterial pressure. Midazolam appeared to be a more effective sedative agent than diazepam for short-term administration during mechanical ventilation. No evidence of cumulation and prolonged recovery was seen.

The cardioprotective effects of lidoflazine, a calcium entry blocker, were tested in patients undergoing multiple aorta-coronary bypass grafting (at least four grafts). Intermittent aortic cross-clamping at 25 degrees to 28 degrees C was used. Mean cross-clamp time was 11 minutes for one distal anastomosis. Patients were randomized into three groups: a control group (I), a group (II) pretreated with 0.5 mg . kg-1 lidoflazine intravenously before cardiopulmonary bypass (CPB), and a group (III) pretreated with 1 mg . kg-1 lidoflazine intravenously. The following markers of ischemia are used: (1) adenosine triphosphate (ATP), creatine phosphate (CP) and glycogen determined in transmural left ventricular biopsy specimens taken at the beginning and end of CPB; (2) ultrastructure in a similar pair of specimens; and (3) hemodynamic recovery 15 minutes after cessation of CPB. At the end of the intervention, ATP decreased to 73% in Group I but remained unchanged in Groups II (98%) and III (88%). CP decreased to 82% in Group I and remained unaltered in Groups II (100%) and III (110%). Glycogen decreased in Group I (to 44%) and in Group II (78%) but remained unchanged in Group II (138%). Ultrastructural study showed better preservation of the glycocalyx and sarcolemma in Group III than in Group I. Left ventricular stroke work index remained unaltered after CPB in Group III but decreased in Groups I and II to about 60% of its initial value. Thus lidoflazine pretreatment protects the myocardium in a dose-dependent manner against deterioration of myocardial function and structure.