Comparison of the effects of ketamine-dexmedetomidine and sevoflurane-sufentanil anesthesia on cardiac biomarkers after cardiac surgery: an observational study.

Inhalational anesthetics have demonstrated cardioprotective effects against myocardial ischemia-reperfusion injury. Clinical studies in cardiac surgery have supported these findings, although not with the consistency demonstrated in experimental studies. Recent investigations have questioned the advantages of inhalational over intravenous anesthetics with respect to cardiac protection. Ketamine has been shown to be comparable with sufentanil, and has even demonstrated anti-inflammatory properties. Dexmedetomidine has been established as a sedative/anesthetic drug with analgesic properties, and has also demonstrated myocardial protective effects. In this retrospective observational study, the influence of ketamine-dexmedetomidine-based anesthesia (KET-DEX group; n=17) on the release of cardiac biomarkers was compared with that of sevoflurane-sufentanil-based anesthesia (SEVO group; n=21) in patients undergoing elective coronary artery bypass grafting. Compared with the SEVO group, the KET-DEX group exhibited significantly reduced cardiac troponin I (2.22+/-1.73 vs. 3.63+/-2.37 microg/l; P=0.02) and myocardial fraction of creatine kinase (CK-MB) levels (12.4+/-10.4 vs. 20.3+/-11.2 microg/l; P=0.01) on the morning of the first postoperative day. Furthermore, cardiac troponin I release, evaluated as the area under the curve, was significantly reduced in the KET-DEX group (32.1+/-20.1 vs. 50.6+/-23.2; P=0.01). These results demonstrate the cardioprotective effects of ketamine-dexmedetomidine anesthesia compared with those of sevoflurane-sufentanil anesthesia.

The effect of medetomidine-ketamine anesthesia on hemodynamic parameters during hemorrhagic shock in minipigs.

Hemorrhagic shock (HS) represents an acute event with high mortality. The optimal combination of anesthetics that would prevent hemodynamic collapse and allow damage control surgery has not yet been determined. We tested the hypothesis that a combination of dissociative anesthetic ketamine with alpha2-agonist medetomidine (MK group, n=10) would provide superior hemodynamic control compared to propofol-remifentanil (PR group, n=10) during HS in minipigs. A modified Wiggers' model of HS with a target mean arterial pressure (MAP) of 40 mm Hg and 2 h duration was used. All minipigs survived. HS led to a ~50 % decrease in cardiac output in both groups (P<0.001 for baseline vs. HS 120 min) with no differences between groups. Total volume of removed blood was larger in the MK group (1321+/-133 ml vs. 1111+/-246 ml in the PR group, respectively; P<0.05). MAP was higher during the initial phases of HS in the MK group than in PR group (P<0.05 at HS 30-90 min). HR was lower in the MK group at the late phases of HS (P<0.05 at HS 60-120 min). In conclusion, medetomidine-ketamine provides a feasible and possibly a more favorable alternative to the propofol-remifentanil combination in our model of HS in minipigs.

[Methylene blue in the therapy of vasoplegic syndrome after cardiac surgery procedure]. / Metylenová modr v lécbe vazoplegického syndromu po kardiochirurgické operaci.

Vasoplegic syndrome after cardiac surgery with cardiopulmonary bypass is severe complication with high morbidity and mortality. Without appropriate therapy the syndrome advances to the shock state with subsequent multiorgan failure. Basic haemodynamic parameters of vasoplegic syndrome include low systemic vascular resistance with severe hypotension, tachycardia, and normal or increased cardiac output and low filling pressures. In therapy norepinephrine and vasopressin or its analogues are used. Methylene blue is other therapeutic option. The case of successful application of methylene blue for the treatment of vasoplegic syndrome is presented.

[Mechanical cardiac support--the first use in Czech Republic]. / Pouzití mechanické srdecní podpory--první zkusenosti v Ceské republice.

BACKGROUND: Implantation of mechanical assist device is widely accepted modality of treatment of patients with refractory heart failure. In the present study we evaluated our first one-year experiences with this method for bridging patients to cardiac transplantation. METHODS AND RESULTS: Between April 2003 and May 2004, the Thoratec VAD (Thoratec, Pleasanton, CA, USA) was implanted in 6 patients ( males; age 28-61 years) as a bridge-to-transplant procedure after having received maximum inotropic support and who were at imminent risk of death. In all patients was performed VAD as biventricular device (BiVAD). During a week after placement was observed recovery of organs function in all patients. Five patients survived to heart transplantation. One patient died 21 days after BiVAD placement due to massive bleeding to the respiratory tract. In post-transplantation period 1 patient died second day from acute graft failure and other patient died 34 days after from intracranial bleeding. Three patients has been discharged from the hospital and they are surviving more than I year. CONCLUSIONS: Analysis of our first experiences with the Thoratec BiVAD implantation as bridging to heart transplantation suggests that it is well suited method with respect to long- term prognosis of this group of patients.

[Far-reaching aspects of the life and work of Sir James Paget]. / Aspectos trascendentales de la vida y la obra de Sir James Paget.

Life, personality and medical heritage left by Sir James Paget are evoked in the centennial of his passing away through this paper.

Aspectos trascendentales de la vida y la obra de Sir James Paget. / Not Available

Life, personality and medical heritage left by Sir James Paget are evoked in the centennial of his passing away through this paper.

[Modern cardiac anesthesia]. / Soucasná kardioanestezie.

Contemporary cardioanaesthesia is based on the use of opioid effects, whereby their dosage is steadily decreased. This calls for supplementation of anaesthesia by further pharmacological preparations which ensure adequate anaesthesia. Despite great efforts, neither, substances available at present nor their combinations are sufficient to suppress surgical stress completely. The authors attempt therefore selective influencing of the sympathetic nerve. In this respect preparations which stimulate sympathetic alpha2 receptors seem promising. The general trend of contemporary cardioanaesthesia is an effort to reduce the time spent by patients in the intensive care unit to a minimum. The motivation are in the first place economic reasons.

[Considerations concerning the award of the first Nobel Prize in Physics to Wilhelm Conrad Röntgen]. / Consideraciones sobre el otorgamiento el primer premio nobel of Física a Guillermo Conrado Röntgen.

By the end of the 19th century, the quantity of scientists of great value was so big that selecting one for the top prize was not easy at all. Opinions were divided, giving rise to the personal controversy depicted in this article.

[Special features of anesthesia during surgery for acquired heart valve defects]. / Nekteré zvlástnosti vedení anestézie u nemocných operovaných pro získané chlopenní vady.

The authors describe some special features as regards anesthesia with large opioid doses in patients operated on account of acquired valvular disease. They emphasize in particular the importance of adequate knowledge of pathophysiological changes associated with the damage of different orifices and their interpretation in the anaesthesiological procedure which is the basis of its success. In the conclusion the authors describe basic haemodynamic changes in combined simultaneous affection of several valves.

[Magnetic resonance tomography (MRT) of the breast in problem patients]. / Magnetresonanztomographie (MRT) der Mamma bei Problempatientinnen.

Over the past few years MRI has become important in the evaluation of inconclusive mammograms. These studies were performed on high-field strength machines, which have the disadvantage of limited accessibility. We evaluated 185 investigations on 169 patients on a 0.5 Tesla MR machine using a dynamic sequence and gadolinium (Gd) DTPA. The results in 107 patients were correlated with the histological findings and MRI assessment proved correct in 44 of 47 benign lesions (93.6%) and 57 of 60 malignant lesions (95%). The 3 false positive results occurred in patients with mastitis, fibroadenoma and an ectatic vessel, respectively. Of the 3 false negative results 2 occurred in patients with microcarcinomas and were due to partial-volume artefacts, whilst the third was due to a technical error. These results compare with those reported in the literature using mainly high-field strength machines. Furthermore, unsuspected second tumours were diagnosed in the ipsilateral breast of 6 women and infiltration of the adjacent thoracic wall in 4 women, findings which had not been evident on mammography. Hence, our results indicate that a mild-field strength MR machine is a valuable tool not only for the non-invasive differentiation between benign and malignant lesions of the breast, but also for planning therapeutic strategy.

Cardioprotective action of sodium gamma-hydroxybutyrate against isoproterenol induced myocardial damage.

In this study, the effects of graded doses of isoproterenol (IP) on the heart were examined in untreated gerbils and in gerbils anaesthetized with gamma-hydroxybutyrate (GHB), an endogenous metabolite with energy sparing properties. We were interested in the cardioprotective potential of GHB. IP was administered intraperitoneally in doses of 0.1, 0.3. 2.5 and 10.0 mg/kg to different groups of gerbils. Half the gerbils in each treatment group received 500 mg/kg of GHB 30 min before IP, and 250 mg/kg at three subsequent 2-hour intervals. The remaining gerbils in each treatment group received saline at these time points. The animals were sacrificed after 8 hours. The accumulation of neutral fat droplets in the sarcoplasm was the most consistent effect of IP. The highest dose also produced some scattered myofibre death. The accumulation of fat in the cells could be estimated semi-quantitatively using a histochemical reaction for succinic dehydrogenase, and the volume of fat could be measured more accurately by electron microscopic morphometry. These measurements showed that IP produced a three to five-fold increase in sarcoplasmic fat volume. GHB either abolished or significantly reduced the accumulation of fat and it also completely prevented the myofibre death caused by the highest doses of IP. This cardioprotective effect of GHB was independent of its hypothermic action. Based on this experience, ultrastructural morphometry of sarcoplasmic fat appears to be a promising method for evaluating cardioprotective measures.

The protective effect of magnesium on acute catecholamine cardiotoxicity in the neonate.

Neonates undergoing heart surgery are exposed to high levels of circulating catecholamines. Our objective was to determine to what extent administration of magnesium counters epinephrine-induced cardiotoxicity. We assessed left ventricular function (pressure-volume data obtained by the conductance catheter/micromanometer technique) and ultrastructure in newborn pigs 3 to 5 days of age before and after administration of epinephrine alone (2 micrograms/kg/min, group A, n = 6) and simultaneously with magnesium sulfate (8 mmol/L, 5 ml/hr, group B, n = 6). Plasma levels of magnesium were maintained at 200% to 250% of control, and ionized calcium was maintained at normal levels. During administration of epinephrine, there was a significant increase in end-systolic elastance from 8.9 +/- 2 to 15 +/- 3 mm Hg/ml in group A and from 7.8 +/- 2 to 16 +/- 3 mm Hg/ml in group B (p < 0.05). This increase was accompanied by an increase in chamber stiffness index (p < 0.05) and shortening of the time constant of isovolumic relaxation (p < 0.05; group A, 19 +/- 3 to 13 +/- 3 msec; Group B, 20 +/- 2 to 15 +/- 2 msec). After epinephrine was discontinued, however, systolic and diastolic indexes returned to baseline levels in group B, whereas group A exhibited a significant reduction in end-systolic elastance (5 +/- 1 mm Hg/ml; p < 0.05) and an increase in chamber stiffness index (0.7 +/- 0.08 versus 0.4 +/- 0.1 ml-1; p < 0.05) and time constant (25 +/- 1 versus 19 +/- 3 msec). Left ventricular dysfunction in group A was associated with focal sarcolemmal rupture and mitochondrial swelling, whereas only minor reversible changes (microvesicular lipid accumulation) were seen in group B. We conclude that magnesium has a protective effect against epinephrine-induced cardiotoxicity because of its blocking action on calcium influx of ionized calcium and could be of therapeutic benefit in the perioperative period.

Effects of high plasma epinephrine and Ca2+ concentrations on neonatal myocardial function after ischemia.

Administration of catecholamines to newborn infants may potentiate reperfusion injury because of increased transsarcolemmal Ca2+ influx and the presence of less developed sarcoplasmic reticulum in the immature hearts. We investigated the effect of administration of epinephrine (1.5 micrograms/kg per minute for 120 minutes) before ischemia and modified serum ionized Ca2+ concentrations in the cardioplegic solution and perfusate on postischemic left ventricular systolic and diastolic function in 25 piglets (5 to 7 days old) undergoing 90 minutes of cold blood cardioplegic arrest. The piglets were divided into four groups; Ca2+ 1.2 mmol/L, group A (n = 6), Ca2+ 0.25 mmol/L, group B (n = 6), Ca2+ 1.2 mmol/L and epinephrine, group C (n = 6), Ca2+ 0.25 mmol/L and epinephrine, group D (n = 7). Left ventricular function was assessed by a conductance catheter in the left ventricle measuring end-systolic and end-diastolic pressure-volume relationships during transient vena caval occlusion. By analysis of covariance, only Ca2+ concentration was important in predicting ventricular function recovery after ischemia (p < 0.01). End-systolic elastance decreased in all groups after ischemia; the magnitude was significantly greater in the normal groups (51% versus 35%, p < 0.01). There was a significant increase in the chamber stiffness index after administration of epinephrine before ischemia (p < 0.05). Groups with low Ca2+ perfusate (B and D) had no change in chamber stiffness index after ischemia. In contrast, there was a significant increase in chamber stiffness in the normal Ca2+ groups with (C) or without (A) epinephrine after ischemia (p < 0.05). Adenosine triphosphate stores declined significantly in the normal Ca2+ groups--48% versus 18% in the low Ca2+ groups (p < 0.01). We conclude that low Ca2+ concentrations in the perfusate and cardioplegic solutions better preserve left ventricular function in the normal and in epinephrine-stressed neonatal heart after ischemia.

[Hemodynamic effects of enoximone in patients with low left ventricular ejection fraction in surgery for ischemic heart disease]. / Hemodynamické úcinky enoximonu u nemocných s nízkou ejekcní frakcí levé komory srdecní operovaných pro ischemickou chorobu srdecní.

Acute heart failure following cardiac surgery in extracorporeal circulation (EC) still poses a formidable problem requiring intensive pharmacological therapy and, often, also mechanical support. Preoperatively reduced left ventricular (LV) function raises the risk for the development of this complication. In their pilot study, the authors evaluated the haemodynamic effects of enoximone, a selective phosphodiesterase III inhibitor, administered at a dose of 1 mg/kg b.w. to 15 patients with a preoperative LV ejection fraction < or = 35% 15 minutes before weaning from EC after an elective myocardial revascularization procedure. All patients were weaned from EC at first attempt without any problems and left the operating theatre in good condition. Enoximone administration led, in the monitored period (45 minutes after administration), to statistically significant increases in cardiac index (+68%; p < 0.01), oxygen supply (+75%; p < 0.01) and oxygen saturation in mixed venous blood (+10%; p < 0.1) and statistically significant decreases in pulmonary and systemic vascular resistance indexes (-52% and -48%, respectively; p < 0.001) and in oxygen extraction (-31%; p < 0.001). These changes were associated with decreases in central venous, mean pulmonary artery, and pulmonary capillary wedge pressure (n.s.). No serious side effects were seen, and the authors conclude enoximone can be the drug of first choice in high-risk patients following heart surgery in EC and requiring inotropic support.

[Coronary surgery at the Institute of Clinical and Experimental Medicine]. / Koronární chirurgie v IKEM.

In 1971-1991 in the Institute of Clinical and Experimental Medicine 2386 operations on account of IHD were performed. 2154 aortocoronary bypasses, 6 Vineberg operations, 51 valvular prostheses and aortocoronary bypasses, 128 resections of left ventricular aneurysms and 47 closures of post-infarction perforations of the interventricular septum. The mortality from aortocoronary bypasses during the entire period was 6.9%. The authors discuss different periods, changes of the operative technique and contemporary views on surgical treatment of IHD.

[Anesthesia using high doses of fentanyl in cardiac surgery]. / Anestézie vysokými dávkami fentanylu v kardiochirurgii.

The authors describe their own experience with anaesthesia using large doses of fentanyl in patients operated on account of ischaemic heart disease and acquired valvular defects. Considerable stability of the circulation and careful monitoring of cardiorespiratory parameters along with aimed influencing of serious deviations is the basis of success of this procedure, which makes it possible to perform cardiosurgery in high risk patients. The authors try to improve the described method further by using some modern procedures.

Age-related response to epinephrine-induced myocardial stress. A functional and ultrastructural study.

Left ventricular systolic and diastolic function before, during, and after a 2-hour intravenous infusion of epinephrine at either 0.5 micrograms/kg/min or 2 micrograms/kg/min were assessed by pressure-volume data obtained by conductance catheter micromanometer technique and correlated with cardiac ultrastructure and plasma levels of epinephrine in neonatal (3-5 days old, n = 12) versus adult (3-4 months old, n = 11) pigs. Administration of epinephrine at 0.5 micrograms/kg/min resulted in an increase in end-systolic elastance (Ees) only in adults, whereas at 2.0 micrograms/kg/min Ees increased in both groups. After 2-hour administration of epinephrine at 2.0 micrograms/kg/min, Ees decreased significantly (p less than 0.05) from the preinfusion baseline value of 8.9 +/- 2 (mean +/- SD) to 5 +/- 1.7 mm Hg/ml, and a significant (p less than 0.05) increase in left ventricular volume elasticity (VdP/dV) from 0.4 +/- 0.02 to 1.4 +/- 0.2 mm Hg occurred in neonates versus no change from baseline in either Ees or VdP/dV in the adults. These changes in the neonates were associated with sarcolemmal rupture and mitochondrial Ca2+ granule deposition versus normal cardiac ultrastructure in the adults. We conclude that the neonatal myocardium is more susceptible to cardiotoxicity from circulating epinephrine.

Cardioprotective effects of sodium gamma-hydroxybutyrate (GHB) on brain induced myocardial injury.

Gamma-hydroxybutyrate (GHB) was evaluated as a protective agent in a gerbil model of non-lethal myocardial injury that follows brain ischaemia. The accumulation of fat droplets in myocardial fibers following brain infarction was measured by electron microscopic morphometry and expressed as a percentage of the area of the sarcoplasm. GHB treatment significantly reduced the area occupied by lipid droplets compared with that found in saline treated controls measured both 10 hours (p less than .005) and 24 hours (p less than 0.05) after unilateral carotid ligation. GHB did not affect the ischaemic swelling of the brain.