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V Piriou

Publications and source records attributed to V Piriou.

At least 37 records · Page 2Linked to original sources
PubMed2000

Prevention of isoflurane-induced preconditioning by 5-hydroxydecanoate and gadolinium: possible involvement of mitochondrial adenosine triphosphate-sensitive potassium and stretch-activated channels.

BACKGROUND: Both mitochondrial adenosine triphosphate-sensitive potassium (MKATP) channels (selectively blocked by 5-hydroxydecanoate) and stretch-activated channels (blocked by gadolinium) have been involved in the mechanism of ischemic preconditioning. Isoflurane can reproduce the protection afforded by ischemic preconditioning. We sought to determine whether isoflurane-induced preconditioning may involve MKATP and stretch-activated channels. METHODS: Anesthetized open-chest rabbits underwent 30 min of coronary occlusion followed by 3 h of reperfusion. Before this, rabbits were randomized into one of six groups and underwent a treatment period consisting of either no intervention for 40 min (control group; n = 9) or 15 min of isoflurane inhalation (1.1% end tidal) followed by a 15-min washout period (isoflurane group; n = 9). The two groups received an intravenous bolus dose of either 5-hydroxydecanoate (5 mg/kg) or gadolinium (40 micromol/kg) before coronary occlusion and reperfusion (5-hydroxydecanoate, n = 9; gadolinium, n = 7). Two additional groups received 5-hydroxydecanoate or gadolinium before isoflurane exposure (isoflurane-5-hydroxydecanoate, n = 10; isoflurane-gadolinium, n = 8). Area at risk and infarct size were assessed by blue dye injection and tetrazolium chloride staining. RESULTS: Area at risk was comparable among the six groups (29 +/- 7, 30 +/- 5, 27 +/- 6, 35 +/- 7, 31 +/- 7, and 27 +/- 4% of the left ventricle in the control, isoflurane, isoflurane-5-hydroxydecanoate, 5-hydroxydecanoate, isoflurane-gadolinium, and gadolinium groups, respectively). Infarct size averaged 60 +/- 20% (SD) in untreated controls versus 54 +/- 27 and 65 +/- 15% of the risk zone in 5-hydroxydecanoate- and gadolinium-treated controls (P = nonsignificant). In contrast, infarct size in the isoflurane group was significantly reduced to 26 +/- 11% of the risk zone (P < 0.05 vs.control). Both 5-hydroxydecanoate and gadolinium prevented this attenuation: infarct size averaged 68 +/- 23 and 56 +/- 21% of risk zone in the isoflurane-5-hydroxydecanoate and isoflurane-gadolinium groups, respectively (P = nonsignificant vs.control). CONCLUSION: 5-Hydroxydecanoate and gadolinium inhibited pharmacologic preconditioning by isoflurane. This result suggests that MKATP channels and mechanogated channels are probably involved in this protective mechanism.

Adenosine Triphosphate↗
PubMed2000

Usefulness of procalcitonin for diagnosis of infection in cardiac surgical patients.

OBJECTIVE: To determine the value of procalcitonin (PCT) as a marker of postoperative infection after cardiac surgery. DESIGN: A prospective single institution three phase study. SETTING: University cardiac surgical intensive care unit (31 beds). PATIENTS: Phase 1: To determine the normal perioperative kinetics of PCT, 20 consecutive patients undergoing elective cardiac surgery with cardiopulmonary bypass were included. Phase 2: To determine whether PCT may be useful for diagnosis of postoperative infection, 97 consecutive patients with suspected infection were included. Phase 3: To determine the ability of PCT to differentiate patients with septic shock from those with cardiogenic shock, 26 patients with postoperative circulatory failure were compared. MEASUREMENTS AND MAIN RESULTS: Phase 1: Serum samples were drawn for PCT determination after induction of anesthesia (baseline), at the end of surgery, and daily until postoperative day (POD) 8. Baseline serum PCT concentration was 0.17 +/- 0.08 ng/mL (mean +/- SD). Serum PCT increased after cardiac surgery with a peak on POD 1 (1.08 +/- 1.36). Serum PCT returned to normal range on POD 3 and remained stable thereafter. Phase 2: In patients with suspected infection, serum PCT was measured at the same time of C-reactive protein (CRP) and bacteriologic samples. Among the 97 included patients, 54 were infected with pneumonia (n = 17), bacteremia (n = 16), mediastinitis (n = 9), or septic shock (n = 12). In the 43 remaining patients, infection was excluded by microbiological examinations. In noninfected patients, serum PCT concentration was 0.41 +/- 0.36 ng/mL (range, 0.08-1.67 ng/mL). Serum PCT concentration was markedly higher in patients with septic shock (96.98 +/- 119.61 ng/mL). Moderate increase in serum PCT concentration occurred during pneumonia (4.85 +/-3.31 ng/mL) and bacteremia (3.57 +/- 2.98 ng/mL). Serum PCT concentration remained low during mediastinitis (0.80 +/- 0.58 ng/mL). Five patients with mediastinitis, two patients with bacteremia, and one patient with pneumonia had serum PCT concentrations of <1 ng/mL. These eight patients were administered antibiotics previously and serum PCT was measured during a therapeutic antibiotic window. For prediction of infection by PCT, the best cutoff value was 1 ng/mL, with sensitivity 85%, specificity 95%, positive predictive value 96%, and negative predictive value 84%. Serum CRP was high in all patients without intergroup difference. For prediction of infection by CRP, a value of 50 mg/L was sensitive (84%) but poorly specific (40%). Comparing the area under the receiver operating characteristic curves, PCT was better than CRP for diagnosis of postoperative sepsis (0.82 for PCT vs. 0.68 for CRP). Phase 3: Serum PCT concentration was significantly higher in patients with septic shock than in those with cardiogenic shock (96.98 +/- 119.61 ng/mL vs. 11.30 +/- 12.3 ng/mL). For discrimination between septic and cardiogenic shock, the best cutoff value was 10 ng/mL, with sensitivity of 100% and specificity of 62%. CONCLUSION: Cardiac surgery with cardiopulmonary bypass influences serum PCT concentration with a peak on POD 1. In the presence of fever, PCT is a reliable marker for diagnosis of infection after cardiac surgery, except in patients who previously received antibiotics. PCT was more relevant than CRP for diagnosis of postoperative infection. During a postoperative circulatory failure, a serum PCT concentration >10 ng/mL is highly indicative of a septic shock.

Adult↗
PubMed2000

[Inhaled nitric oxide: therapeutic applications in cardiac surgery].

The occurrence of right ventricular failure secondary to pulmonary arterial hypertension is a major postoperative complication of cardiac surgery in children and adults. The selective pulmonary vasodilation produced by inhaled nitric oxide (NO) constitutes a fundamental therapeutic advance in the management of this pathology. NO binds immediately with haemoglobin, resulting in its immediate inactivation. This results in perfect maintenance of systemic and coronary blood pressures. A first study performed in 1989 after mitral valve replacement for mitral stenosis with pulmonary hypertension and clinical trials after surgical correction for congenital heart disease and heart transplantation with pulmonary hypertension suggested the efficacy and safety of 20 to 40 ppm NO concentrations in these indications. Potential toxicity of NO (NO2 production by oxidation, methaemoglobin formation) leads to caution with its use. Monitoring of NO concentration and methaemoglobin production is recommended, especially in new-borns.

Administration, Inhalation↗
PubMed1999

[Severe digestive complications after heart surgery using extracorporeal circulation].

PURPOSE: To determine the incidence, circumstances of occurrence and evolution of gastrointestinal complications after cardiac surgery with extracorporeal circulation (ECC). METHODS: Retrospective chart study of gastrointestinal complications in 6.281 patients undergoing ECC between january 1994 and December 1997. RESULTS: Sixty patients developed 68 gastrointestinal complications (1%). Complications included: upper gastrointestinal bleeding (n = 23), intestinal ischemia (n = 19), cholecystitis (n = 7), pancreatitis (n = 6), and paralytic ileus (n = 16). The incidence of these complications was low after coronary artery (0.4%) or valvular surgery (0.8%) and high after cardiac transplantation (6%) and after surgery for acute aortic dissection (9%). Compared with a control population, patients with gastrointestinal complication had a higher Parsonnet score (29 +/- 15 vs 13 +/- 12 points; P = 0.002), were more frequently operated upon as an emergency (40/60, 66% vs 1120/6221, 18%; P = 0.01), underwent ECC of longer duration (114 +/- 66 vs 74 +/- 42 min; P = 0.01), and presented more frequently with low cardiac output after surgery (45/60, 75% vs 435/6221, 7%; P = 0.001). The mortality rate after gastrointestinal complications was 52%. The major factor associated with mortality was the occurrence of sepsis (OR = 38.7). Other factors were: renal failure (OR = 7.9), age > 75 yr (OR = 3.5), mechanical ventilation for more than seven days (OR = 2.7), associated cerebral damage (OR = 3.9). CONCLUSION: Gastrointestinal complications after ECC occur in high risk surgical patients. These complications are frequently associated with other complications leading to a high mortality rate.

Adult↗
PubMed1999

Influence of temperature on tracheal tube cuff pressure during cardiac surgery.

BACKGROUND: Lateral wall pressure may cause tracheal injury by affecting tracheal capillary blood flow. Damage to the trachea is less severe when lateral wall pressure exerted by the endotracheal tube cuff does not exceed the mean capillary perfusion pressure of the mucosa. The purpose of this study was to determine the effects of hypothermic and normothermic cardiopulmonary bypass (CPB) on tracheal tube cuff pressure dynamics. METHODS: Twenty-two patients were studied during normothermic CPB (pulmonary artery blood temperature in the CPB period between 36 and 35 degrees C), and 22 patients during hypothermic CPB (pulmonary artery temperature in the CPB period between 32 and 28 degrees C). A Mallinckrodt Medical Lo-Contour Murphy tracheal tube, with high-volume, low-pressure cuff was used without lubricant. Intracuff pressure (ITCP) was recorded at end-expiration before, during and after cardiopulmonary bypass. RESULTS: ITCP measurements were different between groups during CPB at aortic cross-clamping (13.9 +/- 0.8 mmHg in the normothermic group versus 11.3 +/- 0.4 mmHg in the hypothermic group, P < 0.05), and respectively during CPB after aortic declamping (15.3 +/- 0.8 mmHg and 12.6 +/- 0.8 mmHg, P < 0.05) and after CPB at the end of surgery (16.8 +/- 0.7 mmHg and 18.6 +/- 0.3 mmHg, P < 0.05). CONCLUSION: We conclude that the ITCP is higher in normothermic CPB than in hypothermic CPB; however, the clinical significance of this observation needs further investigation.

Aged↗
PubMed1999

Effects of propofol on haemodynamics and on regional blood flows in dogs submitted or not to a volaemic expansion.

This study was designed to examine the effect of volume loading on haemodynamic responses and regional cardiac function in dogs subjected to two infusion rates of propofol. Instrumentation was established to measure aortic and left ventricular pressures, cardiac output and myocardial segmental lengths. Measurements were taken during two successive infusion rates of propofol: 0.2 (P0.2) and 0.4 (P0.4) mg kg-1 min-1. One group (VL +) (n = 6) received volume loading (dextran 40, 10 mL kg-1 h-1), the other group (VL-) (n = 6) received only basal perfusion (Ringer solution, 2 mL kg-1.h-1). Regional blood flows were measured by radio-labelled microspheres. P0.4 induced a decrease in cardiac output and in dP/dtmax. End-diastolic length decreased with propofol without any difference between groups. Regional contractility was not modified by propofol or by volume loading. P0.4 decreased endocardial and epicardial blood flow in the VL-group only. Renal, small intestine and large intestine blood flows decreased in both groups with P0.4. P0.2 did not alter regional blood flows significantly. It was concluded that in this model, propofol infusion at 0.4 mg kg-1 min-1 induced splanchnic, renal and myocardial hypoperfusion in animals not submitted to a mild fluid loading. Fluid loading allowed myocardial perfusion to be maintained but could not prevent a marked decrease in splanchnic and renal perfusion.

Anesthetics, Intravenous↗
PubMed1999

Effects of dopexamine on blood flow in multiple splanchnic sites measured by laser Doppler velocimetry in rabbits undergoing cardiopulmonary bypass.

Decreased gut perfusion has been reported during cardiopulmonary bypass (CPB). Studies of treatments to avoid splanchnic ischaemia during CPB have given conflicting results. We studied 12 rabbits during mild hypothermic non-pulsatile CPB. Tissue blood flow in three different splanchnic areas (gastric, jejunum and ileum) was measured by laser Doppler velocimetry (LDV) before CPB (T0), after steady state (T1), after administration of dopexamine 2 micrograms kg-1 min-1 (T2) and 4 micrograms kg-1 min-1 (T3), and after return to baseline (T4). Splanchnic blood flow decreased during CPB. Dopexamine increased significantly jejunum LDV (100% at T1 to mean 271 (SD 210)% at T2) and ileum LDV (100% at T1 to 187 (112)% at T2). Gastric LDV was not altered by infusion of dopexamine during CPB. This could partly explain the conflicting results on the value of gastric tonometry as an index of splanchnic injury.

Adrenergic beta-Agonists↗
PubMed1999

Effect of cardiopulmonary bypass on serum procalcitonin and C-reactive protein concentrations.

We have measured serum procalcitonin (PCT) concentrations after cardiac surgery in 36 patients allocated to one of three groups: group 1, coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB) (n = 12); group 2, CABG without CPB (n = 12); and group 3, valvular surgery with CPB (n = 12). Serum PCT and C-reactive protein (CRP) concentrations were measured before operation, at the end of surgery and daily until postoperative day 8. Serum PCT concentrations increased, irrespective of the type of cardiac surgery, with maximum concentrations on day 1: mean 1.3 (SD 1.8), 1.1 (1.2) and 1.4 (1.2) ng ml-1 in groups 1, 2 and 3, respectively (ns). Serum PCT concentrations remained less than 5 ng ml-1 in all patients. Concentrations returned to normal by day 5 in all groups. To determine the effect of the systemic inflammatory response (SIRS) on serum PCT concentrations, patients were divided post hoc, without considering the type of cardiac surgery, into patients with SIRS (n = 19) and those without SIRS (n = 17). The increase in serum PCT was significantly greater in SIRS (peak PCT 1.79 (1.64) ng ml-1 vs 0.34 (0.32) ng ml-1 in patients without SIRS) (P = 0.005). Samples for PCT and CRP measurements were obtained from 10 other patients with postoperative complications (circulatory failure n = 7; active endocarditis n = 2; septic shock n = 1). In these patients, serum PCT concentrations ranged from 6.2 to 230 ng ml-1. Serum CRP concentrations increased in all patients, with no differences between groups. The postoperative increase in CRP lasted longer than that of PCT. We conclude that SIRS induced by cardiac surgery, with and without CPB, influenced serum PCT concentrations with a moderate and transient postoperative peak on the first day after operation. A postoperative serum PCT concentration of more than 5 ng ml-1 is highly suggestive of a postoperative complication.

Aged↗
PubMed1999

Comparison of two semicontinuous cardiac output pulmonary artery catheters after valvular surgery.

OBJECTIVE: To compare semicontinuous cardiac output (CCO) with bolus cardiac output (BCO), in the immediate postoperative period after valvular surgery, under hypothermic cardiopulmonary bypass with two CCO pulmonary artery catheters, based on the pulsed warm thermodilution technique, i.e., Opti-Q from Abbott or IntelliCath from Baxter-Edwards (Abbott and Baxter groups, respectively). DESIGN: Prospective study. SETTING: University hospital. PATIENTS: Forty-four adult patients scheduled for mitral and/or aortic valve surgery were randomized into two groups. Tricuspid or pulmonary valvulopathy diagnosed by echocardiography was excluded. INTERVENTIONS: Cardiac output was measured every 20 mins during the 3 postoperative hrs. BCO was the mean of three boluses (10 mL) of an ice-cold saline solution injected within 3 secs. CCO was the mean of two CCO values obtained in normal mode immediately before and after BCO measurements. MEASUREMENTS AND MAIN RESULTS: Two groups of 22 patients underwent 198 pairs of cardiac output measurements. The mean difference or bias was calculated as the difference between BCO and CCO, and precision was the SD of the mean bias. The limits of agreement were defined as bias +/- 2 SD. A two-sample Wilcoxon's test was used for comparison of bias and precision in sinus and non-sinus rhythm, and stable and unstable mean arterial pressure in each group and between the two pulmonary artery catheters. The coefficient of correlation was also calculated. Bias +/- precision was 0.066+/-0.526 L/min, r2 = .83, for the Abbott group, and 0.015+/-0.490 L/min, r2 = .85 (not significant), for the Baxter group. There was no significant difference within and between groups for bias and precision in sinus and non-sinus rhythm, nor in stable and unstable mean arterial pressure. CONCLUSIONS: This study, during the immediate postoperative period in valvular surgery under hypothermic cardiopulmonary bypass, showed a satisfactory correlation between CCO and BCO with the two systems.

Aged↗
PubMed1999

[Cellular energy metabolism: physiologic and pathologic aspects].

Cellular homeostasis requires permanent energy production and consumption. Adenosine triphosphate (ATP) is the major energy component for the cell. Its synthesis occurs mainly in mitochondria where the oxidative phosphorylations realise the coupling between oxygen consumption and phosphorylation of adenosine diphosphate. The anaerobic production of ATP plays an important role in the intermediary metabolism. The enzymatic complexes of the mitochondrial respiratory chain are energy transducers acting as proton pumps. In cardiomyocytes, the phosphocreatine circuit allows a substrate channelling between mitochondria and myofibrils. This metabolic compartmentation explains the difficulties of studying energetic metabolism in the beating heart and the lack of correlation between cardiac function and the usual energy parameters. Mitochondria are a potential site of action of anaesthetic agents. Lipophilic local anaesthetics impair cellular energy metabolism and mitochondrial ATP production. Such effects could be associated with toxic effects of these molecules. NMR or near-infrared spectroscopy are non invasive techniques for monitoring energetic metabolism in vivo. Clinical applications are developed for analysing brain, muscle or cardiac function in physiological and pathological conditions.

Adenosine Triphosphate↗
PubMed1998

Cardiovascular effects of concomitant administration of isoflurane and nicorandil in dogs.

Nicorandil, a new KATP channel opener, is used in clinical practice for anti-anginal therapy. It exhibits vasodilator properties as does the halogenated anaesthetic isoflurane. We have examined the cardiovascular effects of increasing concentrations of isoflurane after administration of nicorandil in 10 adult beagle dogs anaesthetized with thiopental and whose lungs were ventilated mechanically. During surgery, anaesthesia was maintained with 1.0-1.5% isoflurane. A left thoracotomy was performed and the heart suspended in a pericardial cradle. Monitoring included: ECG; aortic, left ventricular, arterial, central venous and pulmonary artery pressures; cardiac output; coronary flow; and segmental length in the apical region. After surgery, isoflurane anaesthesia was set at an end-tidal concentration of 1.05% (1 MAC) and measurements obtained; these were repeated with 1.4%, 1.75%, 2.1% and 1.05% isoflurane concentrations after appropriate stabilization periods. Nicorandil (100 micrograms kg-1 bolus, 25 micrograms kg-1 min-1 infusion) was begun and a second dose-response study of isoflurane was obtained as before. Blood samples were obtained for measurement of concentrations of nicorandil. Systolic ventricular function was assessed by systolic shortening (%SS) and preload recruitable stroke work (PRSW). Increasing isoflurane concentration produced decreases in heart rate, systolic pressure, cardiac output, %SS and PRSW. Nicorandil produced a slight decrease in systolic arterial pressure (10 and 15 mm Hg after 1.05% and 2.05% isoflurane) and a slight increase in heart rate (10 and 5 beat min-1 after 1.05% and 2.05% isoflurane). Preload, assessed by end-diastolic length, decreased. Coronary blood flow increased with infusion of nicorandil. Left ventricular function was not affected by infusion of nicorandil. We conclude that nicorandil has only minor vaso/venodilatory effects in the presence of isoflurane. Ventricular function was not altered by infusion of nicorandil.

Anesthetics, Inhalation↗
PubMed1998

A comparison of the effects of fentanyl and propofol on left ventricular contractility during myocardial stunning.

BACKGROUND: The intravenous anaesthetic propofol has been shown to possess free radical scavenging activity and calcium channel blocking effects in a number of in vitro models. We decided to compare the effects of propofol with those of fentanyl on myocardial contractility during and after ischaemia to determine whether propofol could protect the heart and improve recovery of ventricular contractile function in open-chested dogs. METHODS: Twenty adult beagles were acutely instrumented, under halothane anaesthesia, to measure ECG; aortic, left ventricular pressures; cardiac output; coronary flow; and segmental lengths in the regions perfused by the left anterior and left circumflex coronary arteries. After surgery and a stabilisation period halothane anaesthesia was terminated and fentanyl (100 microg x kg[-1] bolus followed by 2 microg x kg[-1] x min[-1] infusion; n=10) or propofol (5 mg x kg[-1] bolus followed by 0.3 mg x kg[-1] x min[-1] infusion; n=10) anaesthesia commenced. After a stabilisation period the LAD coronary artery was occluded for 10 min and then reperfused for 3 h. Measurements were taken throughout the protocol. RESULTS: We found no significant difference in recovery of contractile function between propofol and fentanyl as assessed by normalised preload recruitable work area (50+/-10 vs 47+/-16%), normalised systolic shortening (36+/-12 vs 48+/-14%) and peak left ventricular dP/dt (1665+/-276 vs 1846+/-151 mmHg x s[-1]) at the end of reperfusion. CONCLUSION: We conclude that at the concentration used in this study propofol shows no improvement in contractility during "stunning" when compared to fentanyl.

Anesthetics, Intravenous↗
PubMed1998

Myocardial effects of isoflurane in healthy infants and small children. Assessment by continuous oesophageal aortic blood flow echo-Doppler.

BACKGROUND: In paediatric healthy patients and in real peroperative conditions, the cardiovascular effects of isoflurane have been poorly described. METHODS: We have evaluated the myocardial effects of 1% end-expired concentration (EEC) of isoflurane in 25 healthy infants or small children undergoing superficial surgical therapy for small burns with a continuous aortic blood flow echo-Doppler device. Aortic blood flow (ABF) was measured with a small oesophageal probe specially designed for infants. The aortic flowmeter was connected with satellite devices to visualize the haemodynamic profile variations during the isoflurane inhalation period. RESULTS: Isoflurane significantly decreased ABF and increased pre-ejection period/left ventricular ejection time (PEP/LVET), when compared with control values previously recorded 5 min after induction with halothane-fentanyl and atracurium (respectively, 80 +/- 7%, mean +/- SD; P < 0.001 and 111 +/- 11%; P = 0.017, 5 min after EEC of isoflurane reached 1%, then respectively, 75 +/- 12%; P < 0.001 and 119 +/- 16%; P < 0.001, at the end of the isoflurane inhalation period). These variations reversed to a great extent when isoflurane was switched off (97 +/- 17% for ABF; P = 0.08 and 105 +/- 12% for PEP/LVET; P = 0.75). Among the usual parameters, 1% EEC of isoflurane caused no significant changes in heart rate, moderately decreased mean arterial pressure (successively, 88 +/- 12%; P = 0.045 and 87 +/- 19%; P = 0.049), but belatedly decreased end-tidal CO2 pressure (87 +/- 11% at the end of the inhalation period (P < 0.001) which persisted 5 min after isoflurane was turned off (90 +/- 11%; P < 0.001)). CONCLUSIONS: These findings suggest that isoflurane can transiently depress cardiac function in healthy infants.

Anesthetics, Inhalation↗
PubMed1997

Caval occlusion alters the shape of the ischemic and nonischemic pressure-length loop.

OBJECTIVES: The effects of changes in preload on paradoxical myocardial wall motion during ischemia have been previously studied. However, the studies have been performed using slow volume changes. It was decided to study the effects of fast changes in preload, which would occur during caval occlusion, on the regional pressure-length loops during ischemia. DESIGN: Retrospective trial. SETTING: Experimental animal laboratory in a university medical center. PARTICIPANTS: Ten anesthetized adult dogs. INTERVENTIONS: In an open chest preparation, regional ischemia was achieved by occluding the left anterior descending coronary artery for 10 minutes, with sudden caval occlusions being performed to assess the influence of preload on wall motion. MEASUREMENTS AND MAIN RESULTS: Left ventricular pressure and regional segmental lengths were measured. During caval occlusion, beat by beat, percent postsystolic shortening and percent systolic bulging in the ischemic region, percent isovolumetric shortening in the nonischemic region, and percent systolic shortening in both regions were calculated. Caval occlusion significantly decreased the end-diastolic pressure (12.62 +/- 1.02 to 3.39 +/- 0.59 mmHg) and length. In the ischemic area, although systolic shortening became more negative (-1.8 +/- 0.79% to -9.65 +/- 1.08%), postsystolic shortening (9.66 +/- 0.73% to 15.53 +/- 1.2%) and systolic bulging (4.6 +/- 0.49% to 12.67 +/- 1.04%) increased. In the nonischemic area, systolic shortening decreased slightly but significantly (18.01 +/- 3.24% to 14.93 +/- 3.64%) as isovolumetric shortening increased (2.77 +/- 0.68 to 7.37 +/- 1.29%). Caval occlusion increased the rightward shift and accentuated the distortion of the ischemic loop. The nonischemic loop displayed a leftward shift of the systolic isovolumetric component and a slight decrease in percent total length change. CONCLUSION: Caval occlusion modifies the shape of the pressure-length loop of the ischemic myocardium. This change in shape may interfere with the assessment of regional systolic indexes obtained by caval occlusion in ischemic hearts.

Animals↗
PubMed1997

Beneficial effect of concomitant administration of isoflurane and nicorandil.

In common with halogenated anaesthetics, nicorandil, a new KATP channel opener, has been shown to have cardioprotective and vasodilator effects. Recent studies have also suggested that the vasodilator and protective effects of halogenated anaesthetics are mediated partly via KATP channel opening. This study examined the effects of concurrent administration of nicorandil and isoflurane on haemodynamic state and ventricular function before, during and after 15 min of ischaemia. We studied left ventricular function in 40 anaesthetized rabbits using ultrasonomicrometry. Measurements were obtained before, during and after 15 min of regional ischaemia. Regional ventricular function was assessed in terms of systolic shortening (SS%) and preload recruitable work area (PRWA, the area beneath the regional stroke work vs end-diastolic length relationship) during reperfusion. Four groups were studied: group F (n = 10) received a bolus dose of fentanyl 100 micrograms kg-1 and then 400 micrograms kg-1 h-1 throughout; group 1 (n = 10) received 2.05% end-tidal concentration of isoflurane (1 MAC); group FN (n = 10) received fentanyl, a bolus does of nicorandil 100 micrograms kg-1 and then 25 micrograms kg-1 min-1, 15 min before occlusion; and group IN (n = 10) received isoflurane and nicorandil. Isoflurane decreased left ventricular systolic pressure and ventricular contractility (+dP/dtmax, slope of preload recruitable stroke work, and SS%). Nicorandil increased -dP/dtmax in group FN. Post-ischaemic regional left ventricular contractility in group I did not differ from that in group F, however, groups receiving nicorandil recovered to a greater extent. Group IN showed better recovery compared with all other groups when ventricular contractility was assessed by PRWA normalized to pre-occlusion values (mean 99.3 (SEM 10.5)% vs 73.4 (7.5)%, 50.2 (5.8)% and 52.4 (3.7)% at 120 min reperfusion in groups FN, I and F, respectively). Tissue ATP and lactate contents did not differ between groups. We conclude that concurrent administration of nicorandil and isoflurane enhanced post-ischaemic recovery compared with isoflurane anaesthesia or nicorandil and fentanyl administration.

Adenosine Triphosphate↗
PubMed1996

Severe systemic cholesterol embolization after open heart surgery.

Cholesterol crystal embolization (CCE) may be triggered by various factors: intra-arterial angiographic procedures, aortic or vascular surgery, anticoagulant or thrombolytic treatments, or both. There are few previous reports of patients undergoing coronary artery bypass grafting (CABG) experiencing and therefore displaying severe systemic CCE. We describe four patients presenting, shortly after CABG, cutaneous, renal, neurological and hepatic signs related to severe CCE confirmed by skin biopsy. All patients died 11-92 days after surgery. As systemic CCE reveals severe atheromatous disease and is associated with a poor prognosis, it is advisable to avoid CABG in patients who present symptoms of CCE before surgery.

Aged↗