thiopental and Coronary-Disease

Successful management of a patient with heart disease requires an understanding not only of the pharmacology of anesthesia but also of the pathophysiology of heart disease. Both of these factors as well as the choice and conduct of anesthesia by the anesthesiologist are thoroughly explored in this article.

Topics: Aged; Anesthesia, Conduction; Anesthesia, Inhalation; Anesthesia, Intravenous; Anesthetics; Benzodiazepines; Cardiovascular System; Child; Coronary Disease; Halothane; Heart Diseases; Heart Valve Diseases; Humans; Morphine; Nitrous Oxide; Succinylcholine; Surgical Procedures, Operative; Thiopental; Tubocurarine

The performance of the cardiovascular system depends on the interaction of the left ventricle and arterial system. An appropriate coupling of these two components is important to quantify the efficiency of myocardium, determined by Ea/Ees. The end-systolic elastance of the left ventricle (Ees) is an index of contractility which is independent of loading conditions, while the arterial end-systolic elastance (Ea) represents the properties of the arterial system. The aim of our study is to investigate the effects of a bolus of remifentanil (R) on myocardial efficiency.. In a period of 3 months we examined prospectively the effects of R in a group of 12 patients, ASA IV, 49-75 years old, submitted intraoperatively to cardiac anesthesia for revascularization of myocardium. After induction of anesthesia and before the beginning of surgery, a bolus of R (1 mg/kg/min) was administered and with the use of trans-esophageal echocardiography we determined both the left ventricle end-systolic volume and end-diastolic volume to assess, with different end-systolic arterial pressures, the ventricle elastance (Ees) and arterial elastance (Ea) before and after administration of R.. The present findings indicate that R decreases the ventricular elastance from 6.07 mmHg/ml/m2 to 4.8, with a less decrease of arterial elastance from 3.69 mmHg/ml/m2 to 3.07.. The results suggest that R preserves a good left ventricular-arterial coupling and mechanical efficiency, despite a little increase of coupling, probably because ventricular and arterial properties are so matched as to minimize the systolic work of the left ventricle.

Topics: Aged; Anesthetics, Intravenous; Aorta; Cardiovascular Agents; Combined Modality Therapy; Coronary Artery Bypass; Coronary Disease; Echocardiography, Transesophageal; Electric Impedance; Female; Heart Failure; Heart Rate; Hemorheology; Humans; Injections, Intravenous; Male; Middle Aged; Myocardial Contraction; Myocardial Infarction; Oxygen Consumption; Piperidines; Propofol; Prospective Studies; Remifentanil; Stroke Volume; Thiopental; Vascular Resistance; Vecuronium Bromide; Ventricular Function, Left

Postoperative delirium is a common sequel of cardiopulmonary bypass that is hard to diagnose correctly, difficult to predict and almost impossible to prevent and to treat. The aim of this study is to evaluate the frequency of postoperative cognitive disorders and cerebral hypoperfusion in patients receiving either high dose fentanyl or thiopentone anesthesia in cardiac surgery.. 50 unpremedicated patients, Class IIb-NYHA (25 patients in each group suffering from single critical LAD disease) undergoing elective coronary artery bypass grafting surgery were randomly allocated into two groups either to receive fentanyl 50 microg/kg with diazepam 0.1 mg/kg (Group 1) or thiopentone 7 mg/kg (Group 2) for the induction of anesthesia. Anesthesia was maintained with fentanyl 2 microg/kg/hr and diazepam 0.05 mg/kg/hr infusion in Group 1 throughout the procedure. In Group 2, it was maintained with enflurane 0.7-1.5% before and after cardiopulmonary bypass (CPB) and with thiopentone 3 mg/kg/hr infusion during CPB. Neuropsychiatric evaluation (STAI-T, min mental state examination-MMSE and Zung tests), EEG and SPECT rCBF (Single Photon Emission Computed Tomography Regional Cerebral Blood Flow) studies were performed preoperatively, early and late postoperatively. The patients that were diagnosed to have postoperative cerebral hypoperfusion also underwent computed tomography scanning postoperatively.. Eleven patients (9 from fentanyl and 2 from thiopentone group) were diagnosed to have cerebral hypoperfusion with respect to SPECT rCBF studies. Seven of these patients (5 from fentanyl and 2 from thiopentone) were diagnosed to be in a state of delirium clinically with MMSE tests.. High dose fentanyl anesthesia causes significant predisposition to postoperative cerebral hypoperfusion when compared with barbiturate anesthesia in cardiac surgery. Hypoperfusion as demonstrated by SPECT rCBF studies may play an important role in the pathophysiology of mental disorders, i.e., postoperative delirium.

Topics: Adult; Anesthetics, Intravenous; Cerebrovascular Circulation; Coronary Artery Bypass; Coronary Disease; Female; Fentanyl; Humans; Hypnotics and Sedatives; Male; Middle Aged; Postoperative Complications; Thiopental

Two intravenous induction techniques were compared with respect to changes in ejection fraction (EF) and central hemodynamics in 30 patients scheduled for coronary artery surgery. Left ventricular EF was measured with a collimated single crystal probe linked to a microcomputer, after injection of 200 MBq Tc 99 m HSA. Stroke volume index (SI) determined by thermodilution and EF were used to calculate left ventricular volume in end-systole and end-diastole. In 20 patients (Group I), anesthesia was induced with diazepam (94 micrograms x kg-1), thiopentone (3 mg x kg-1) and fentanyl (3 micrograms x kg-1). In 10 patients (Group II), fentanyl (30 micrograms x kg-1) was used for induction. In Group I, EF decreased from 0.43 to 0.26 at intubation, while systemic vascular resistance index (SVRI) showed an increase. Left ventricular volume decreased during induction of anesthesia except during intubation. In Group II, EF and left ventricular volume remained unchanged during the study period. SVRI showed no increase at intubation. No change in contractility was indicated from the relation between the end-systolic pressure and volume, in any of the groups.

Topics: Anesthesia, Inhalation; Anesthesia, Intravenous; Clinical Trials as Topic; Coronary Artery Bypass; Coronary Disease; Diazepam; Female; Fentanyl; Humans; Male; Middle Aged; Random Allocation; Stroke Volume; Thiopental

In patients undergoing cardiac surgery, the induction of anesthesia is not without risk because of specific cardiovascular effects of the anesthetic and the preoperative state of the patient. The hemodynamic effects of etomidate, midazolam, thiopental, and methohexital are well known: etomidate is an anesthetic that induces only minor cardiovascular changes; its influence on the endocrine system, however, has reduced its clinical indication. Barbiturates such as thiopental and methohexital produce negative inotropic effects in combination with an increase in heart rate and myocardial oxygen consumption; midazolam reduces pre- and afterload in patients with poor left ventricular function. Propofol, a new short-acting induction agent with good anesthetic properties, is said to diminish arterial pressure as well as myocardial oxygen consumption.. In a randomized study we investigated the hemodynamic effects of intravenous induction with propofol (2 mg/kg body wt.), thiopental (5 mg/kg), methohexital (1 mg/kg), etomidate (0.3 mg/kg), and midazolam (0.15 mg/kg) in 50 patients undergoing coronary artery bypass grafting. All patients were premedicated with flunitrazepam (0.03 mg/kg up to 2 mg) and morphine hydrochloride (0.2 mg/kg up to 15 mg) 100 min before the investigation. After 0.003 mg/kg fentanyl the patients received the induction agent in the above-mentioned dosage within 40 s followed by 0.1 mg/kg pancuronium bromide. Hemodynamic measurements were performed 1, 3, and 5 min after the end of the injection as well as 1 and 5 min after intubation.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Anesthesia, General; Anesthetics; Clinical Trials as Topic; Coronary Artery Bypass; Coronary Disease; Etomidate; Hemodynamics; Humans; Methohexital; Midazolam; Phenols; Propofol; Thiopental

The purpose of this study was to evaluate intravenous nitroglycerin given during induction of anesthesia as a means for prevention of myocardial ischemia and hemodynamic changes associated with induction, laryngoscopy, and intubation, in patients with stable angina scheduled for vascular operations of moderate duration. Forty-six patients were randomly assigned to receive either fentanyl, 3 micrograms/kg (group 1, n = 6), fentanyl, 8 micrograms/kg (group 2, n = 20), or fentanyl 3 micrograms/kg plus a continuous intravenous nitroglycerin infusion, 0.9 microgram X kg-1 X min-1 (group 3, n = 20), in addition to thiopental-pancuronium anesthetic induction, prior to laryngoscopy and intubation. The criteria for recognizing myocardial ischemia were the following: horizontal or downsloping ST segment depression equal to or greater than 1 mV, and/or ventricular arrhythmia, on CM5 recording. In group 1, myocardial ischemia occurred during laryngoscopy and intubation in four patients, and mean blood pressure (MBP), heart rate, and mean pulmonary wedge pressure (PCWP) increased significantly (P less than 0.05). Despite greater stability in MBP and heart rate in group 2, myocardial ischemia still occurred in four patients (not significantly different from group 1). Nitroglycerin added to low-dose fentanyl (group 3) produced significant reduction in myocardial ischemia (1/20) when compared with group 1 (P less than 0.01), and significantly greater stability in PCWP during laryngoscopy and intubation in comparison to groups 1 and 2. In patients with stable angina undergoing operations of short duration, the use of nitroglycerin infusion and low-dose fentanyl significantly decreases the incidence of myocardial ischemia associated with induction of anesthesia and tracheal intubation.

Topics: Aged; Anesthesia, Local; Blood Pressure; Coronary Disease; Electrocardiography; Female; Fentanyl; Heart Rate; Humans; Laryngoscopy; Male; Middle Aged; Morphine; Nitroglycerin; Pancuronium; Preanesthetic Medication; Pulmonary Wedge Pressure; Stroke Volume; Thiopental; Vascular Resistance

Twenty patients scheduled for elective coronary surgery received either propofol ('Diprivan') 1.5 mg/kg in emulsion or thiopentone 2 mg/kg for induction of anaesthesia. Vecuronium was used for neuromuscular blockade. Cardiovascular dynamics were recorded every minute until 6 min after intubation. Anaesthesia with propofol was accompanied by a reduction in arterial pressure, the decrease being severe in two patients. This was largely due to a decrease in systemic vascular resistance. Thiopentone anaesthesia resulted in a smaller decrease in arterial pressure, but a marked increase in arterial pressure followed endotracheal intubation. Although the absence of haemodynamic changes following intubation during propofol anaesthesia is advantageous to the ischaemic myocardium, this has to be balanced by the variable and sometimes severe reduction in arterial pressure that occurred on induction.

Topics: Anesthesia, Intravenous; Coronary Disease; Female; Hemodynamics; Humans; Male; Middle Aged; Phenols; Propofol; Thiopental

The haemodynamic responses to induction and tracheal intubation have been studied in patients with coronary artery disease randomly assigned to a labetalol pretreatment group (n = 14) or to a placebo group (n = 16). Twelve hour before operation, treated patients received a bolus dose of labetalol 0.5 mg kg-1 followed by a constant infusion of 0.1 mg kg-1 h-1 i.v. Anaesthesia was induced with thiopentone and phenoperidine, and intubation performed following the administration of suxamethonium. At intubation, the changes in heart rate (P less than 0.01), mean arterial pressure (P less than 0.05) and rate-pressure product (P less than 0.01) were significantly smaller in the labetalol group compared with the placebo group. Labetalol pretreatment appears satisfactory and may be useful in patients with coronary artery disease who have a normal left ventricular ejection fraction.

Topics: Anesthesia, General; Blood Pressure; Cardiac Output; Clinical Trials as Topic; Coronary Disease; Double-Blind Method; Ethanolamines; Female; Heart Rate; Hemodynamics; Humans; Intubation, Intratracheal; Labetalol; Male; Middle Aged; Pulmonary Wedge Pressure; Thiopental; Vascular Resistance

We investigated the cardiovascular effects of intravenous thiopentone (3.0 mg/kg), etomidate (0.3 mg/kg), althesin (0.07 ml/kg), ketamine (1.5 mg/kg), diazepam (0.15 mg/kg) and flunitrazepam (0.015 mg/kg) alone and after the addition of fentanyl (0.01 mg/kg) during induction of anaesthesia in 46 premedicated patients subjected to coronary artery bypass surgery. Thiopentone, etomidate or diazepam caused only small changes in the haemodynamic determinants of myocardial oxygen supply and demand (arterial pressure, heart rate, left and right ventricular filling pressure) in patients with coronary artery disease in whom global resting left ventricular function was normal. Althesin and flunitrazepam produced a significant fall in arterial pressure, cardiac index and stroke index; heart rate increased after the administration of althesin. Ketamine markedly elevated systemic and pulmonary pressure, heart rate, systemic and pulmonary vascular resistance, right and left ventricular filling pressure. The subsequent administration of fentanyl was associated with a further decrease in arterial pressure in the althesin and flunitrazepam group. The circulatory stimulating effects of ketamine were largely abolished by fentanyl. None of the induction procedures was associated with cardiovascular stimulation during laryngoscopy and tracheal intubation.

Topics: Alfaxalone Alfadolone Mixture; Anesthesia, Intravenous; Coronary Artery Bypass; Coronary Disease; Diazepam; Etomidate; Fentanyl; Flunitrazepam; Hemodynamics; Humans; Ketamine; Myocardium; Oxygen Consumption; Preanesthetic Medication; Thiopental

Maintenance of anaesthesia with volatile anaesthetic agents affects the perioperative course of patients undergoing off-pump coronary artery bypass (OPCAB) surgery. This facilitates adequate depth of anaesthesia, reduction in need of analgesic dosage, early extubation and transfer from Intensive Care Unit. We compared two volatile anaesthetic agents sevoflurane and isoflurane in terms of haemodynamic effects, amount of analgesic needed during surgery, quantity of agent needed for maintenance of anaesthesia and postoperative recovery in 40 patients undergoing OPCAB surgery. Anaesthesia was induced with fentanyl, midazolam and thiopentone, and vecuronium was used for muscle relaxation. An Octopus stabiliser was used and coronary anastomosis was performed using internal mammary artery and saphenous vein grafts. Routine monitoring was performed. The depth of anaesthesia was monitored using Bispectral index monitor. The inspired/expired concentration of anaesthetic agents to maintain the desired BIS and the amount of volatile anaesthetic agent needed was also noted. The amount of analgesic used intraoperatively was noted in both the groups. The 'time of awakening' defined as eye opening on verbal commands, and time of extubation were noted. There were no differences in haemodynamic parameters, depth of anaesthesia, and quantity of agent needed, but patients in isoflurane group required more intraoperative analgesics than sevoflurane group. Time of awakening (48+/-13 vs 114 +/- 21 mins; P < 0.001) and subsequent extubation (124 +/- 25 vs 177 +/- 36 mins, P<0.001) was earlier in sevoflurane group than isoflurane group. There was no evidence of perioperative myocardial infarction in both the groups. We conclude that sevoflurane and isoflurane can both be safely used in OPCAB surgery, but the awakening and extubation times are significantly less with sevoflurane.

Topics: Aged; Anesthesia Recovery Period; Anesthetics, Inhalation; Anesthetics, Intravenous; Blood Pressure; Cardiac Output; Coronary Artery Bypass, Off-Pump; Coronary Disease; Female; Fentanyl; Heart Rate; Humans; Internal Mammary-Coronary Artery Anastomosis; Isoflurane; Male; Methyl Ethers; Midazolam; Middle Aged; Respiration; Sevoflurane; Thiopental; Time Factors; Treatment Outcome

Topics: Adrenergic beta-Antagonists; Coronary Disease; Drug Overdose; Heart Arrest; Humans; Thiopental

This study evaluates the effects of 30 min increasing doses infusions of six intravenous anesthetic agents (thiopental, etomidate, propofol, fentanyl, sufentanil and alfentanil) on regional ventricular function in a normal and an acute ischemic heart segment in dogs. Part 1 discusses the methodology used in this experimental design with emphasis on the sensitivity and the limitations of the parameters used to assess ventricular performance and contractility. Part 2 reports the effects on regional and global ventricular function, which occur when one segment is made acutely ischemic. Part 3 reports and discusses the effects of increasing infusions of the three induction agents thiopental, etomidate and propofol on systemic and regional ventricular function. These agents induced a dose-dependent decrease in left ventricular end-systolic pressure. End-diastolic length also decreased in the normal and the acute ischemic segment for the three agents, indicating a decrease in left ventricular loading. This effect was most pronounced for propofol. At the doses tested, etomidate did not alter regional myocardial function significantly in any of the two segments. Thiopental, on the other hand was associated with a dose-dependent decrease in systolic shortening, that was significantly greater in the ischemic segment. This suggested that thiopental depresses myocardial function more in the acute ischemic heart than in the normal heart. Propofol decreased systolic shortening similarly in both segments. In part 4 the effects of the three narcotics fentanyl, sufentanil and alfentanil are reported. Fentanyl and sufentanil induced a dose-dependent decrease in heart rate. Left ventricular end-systolic pressure remained unchanged despite the increasing infusion rate. Fentanyl increased regional end-diastolic length and systolic shortening at the highest infusion rate. This phenomenon is not apparent for sufentanil, suggesting that different mechanisms are involved to compensate for the expected bradycardia-induced hypotension. Alfentanil did not alter systemic and regional hemodynamics significantly in this study design.

Topics: Alfentanil; Animals; Coronary Disease; Dogs; Etomidate; Female; Fentanyl; Hemodynamics; Infusions, Intravenous; Male; Propofol; Sufentanil; Thiopental; Ventricular Function

The effects of propofol and thiopentone on myocardial contractility and global ischaemia were evaluated using an isolated non-working perfused rat heart preparation. Contractility was assessed using a tension transducer linked to the cardiac apex, and the contractility was expressed as a ratio of the deflection size before and after infusion of the drug. Ischaemia-induced leakage of myocardial proteins and ions (potassium and magnesium) was assessed by comparing the concentrations in the effluent perfusate immediately before and after 60 min of isothermic ischaemia, in the presence of propofol, thiopentone or plain Krebs' buffer solution (control). Mean contractility ratios of 1.15 and 1.3 were obtained with control and propofol groups respectively (NS), but were reduced to 0.5 in the thiopentone group (P less than 0.001). The magnitude of the post-ischaemic leakage of proteins and potassium was similar in each group; however, the post-ischaemic leakage of magnesium was greater in the thiopentone group than in the propofol or control groups. These data suggest that, compared with thiopentone, propofol is not a potent negative inotrope, and that it may cause less disturbance of myocardial magnesium homeostasis during myocardial ischaemia.

Topics: Animals; Coronary Disease; Magnesium; Male; Myocardial Contraction; Myocardium; Perfusion; Potassium; Propofol; Proteins; Rats; Rats, Inbred Strains; Thiopental

The aim of the study was to assess the influence of general anaesthesia on electrocardiographic and arrhythmogenic responses to left anterior descending coronary artery occlusion.. Pigs weighing 18-20 kg were anaesthetised with alpha chloralose 100 mg.kg-1 (n = 9) or thiopentone 30 mg.kg-1 (n = 9) and the arrhythmogenic effects of coronary artery occlusion were examined by sequential electrocardiographic measurements every 5 min and arrhythmia analysis every minute over a 60 min period.. alpha Chloralose predisposed to lower ST segment elevation (analysis of variance for repeated measurements p less than 0.002), less marked epicardial conduction delay (p less than 0.01) with slower progression to monophasic potentials, and in contrast, to a greater number of episodes of ventricular premature beats (p less than 0.005), ventricular tachycardia (51 v 32 episodes), and ventricular fibrillation (6 v 2 pigs) than barbiturate anaesthesia.. alpha Chloralose and barbiturates exerted opposite electrocardiographic and arrhythmogenic effects in a porcine model of acute myocardial ischaemia. Due to its proarrhythmic effect chloralose should probably be used in studies dealing with spontaneous and induced ischaemic arrhythmias.

Topics: Anesthesia, General; Animals; Arrhythmias, Cardiac; Cardiac Complexes, Premature; Chloralose; Coronary Disease; Electrocardiography; Heart; Swine; Thiopental; Ventricular Fibrillation

The effects of 30-min infusions of thiopental (20, 30, 40, 50, 60, and 70 mg.kg-1.h-1), etomidate (2.4, 3.6, 7.2, 9.6, 12, and 14.4 mg.kg-1.h-1), and propofol (6, 9, 12, 15, 18, and 21 mg.kg-1.h-1) on regional hemodynamic variables in the normal and acute ischemic heart segment were studied in dogs using ultrasonic segment length gauges. The three agents were associated with a dose-dependent decrease in end-diastolic length, indicating a decrease in left ventricular filling. This effect was most pronounced for propofol. At the doses tested, etomidate did not significantly alter regional myocardial function. Thiopental, however, was associated with a dose-dependent decrease in systolic shortening, which was significantly greater in the ischemic segment. These findings confirm the hemodynamic stability seen with etomidate and show that thiopental depresses myocardial function more in the acute ischemic heart than in the normal heart. The decrease in systolic shortening associated with propofol was similar in the normal and in the acute ischemic heart segment.

Topics: Animals; Coronary Disease; Dogs; Etomidate; Female; Heart; Hemodynamics; Infusions, Intravenous; Male; Myocardial Contraction; Propofol; Thiopental

A comparison of haemodynamic stability with respect to arterial pressure, heart rate and cardiac output between six commonly used anaesthetic techniques: fentanyl (FE), halothane (HAL), morphine (MO), fentanyl/droperidol (NLA), and thiopentone (two dose levels: PE 3 and PE 6), all supplemented with nitrous oxide, was performed during induction of anaesthesia and sternotomy in 47 patients with good left ventricular function and maintained beta-blockers undergoing coronary bypass surgery. Interventions were kept to a minimum in order to characterize each anaesthesia group. Statistically, the material fell into two parts. The MO, PE 3 and PE 6 groups showed good stability under steady-state anaesthesia, but variable and often extensive hyperdynamic responses were seen to endotracheal intubation and surgical stimulation. The FE, HAL and NLA groups were characterized by a good stability during the induction-intubation phase but were unstable when combined with nitrous oxide in the absence of noxious stimuli.

Topics: Adrenergic beta-Antagonists; Anesthesia, General; Anesthetics; Coronary Artery Bypass; Coronary Disease; Droperidol; Female; Fentanyl; Halothane; Hemodynamics; Humans; Intubation, Intratracheal; Male; Middle Aged; Morphine; Nitrous Oxide; Preanesthetic Medication; Sternum; Thiopental

A comparison between five anaesthetic procedures, fentanyl (FE), morphine (MO), halothane (HAL), fentanyl/droperidol (NLA) and thiopenthone (two dose levels: PE 3 and PE 6), all supplemented with nitrous oxide, was performed with respect to the left ventricular function (LVF) during anaesthesia induction and sternotomy in 47 patients with good preoperative LVF and maintained beta-blockers. Peroperative LVF was characterized by left ventricular stroke volume (stroke index) and external pressure volume stroke work (left ventricular stroke work index) in relation to filling pressure (pulmonary capillary wedge pressure) and outflow resistance (systemic vascular resistance). The individual patient patterns in each group indicated normal LVF in the awake state. Anaesthesia induction was followed by a moderate depression of LVF in the HAL, MO, PE 3 and PE 6 groups at full dose of anaesthetic agent. After addition of nitrous oxide, there was also a decrease of preload in all groups, masking any additional depressions of LVF. The response to external stimuli, endotracheal intubation and sternotomy was that of mildly depressed LVF in the majority of the patients. The haemodynamic reactions in the FE and NLA groups were more varied. In all groups some patients (approximately 30%) showed signs of left ventricular failing in response to external stimuli. With the exception of the more variable haemodynamic reactions in the FE and NLA groups, the differences between the anaesthesia groups with respect to LVF depended mainly on extracardiac factors.

Topics: Anesthesia; Coronary Disease; Droperidol; Female; Fentanyl; Halothane; Heart Ventricles; Humans; Male; Middle Aged; Morphine; Nitrous Oxide; Pulmonary Circulation; Sternum; Stroke Volume; Thiopental

The effect of thiopental (100 mg X 1(-1] during total ischemia, low-flow ischemia, and severe hypoxia with maintained flow was investigated in the isolated perfused rat heart. During total ischemia the rate of decline of tissue creatine phosphate and adenosine triphosphate was no different in thiopental-treated and untreated hearts. The development of ultrastructural damage during total ischemia, the release of creatine kinase on reperfusion, and the exacerbation of ultrastructural damage after reperfusion were unaffected by thiopental. When thiopental was added to the perfusate during hypoxia and during low-flow ischemia at a normal pH(7.4), creatine kinase release during reoxygenation and during reperfusion was significantly less (P less than 0.005 and P less than 0.05, respectively) than in the untreated groups. After low-flow ischemia at a low pH (6.5), creatine kinase release was no different in thiopental-treated and untreated hearts. Thus, thiopental afforded protection of the myocardium in hypoxia and low-flow ischemia at pH 7.4 but not in total ischemia and low-flow ischemia at pH 6.5. The data are consistent with the hypothesis that during total ischemia and low-flow ischemia at pH 6.5, acidosis favors the entry of thiopental into the cell, causing inhibition of mitochondrial function and reduction of ATP production. During hypoxic perfusion and low-flow ischemia at pH 7.4, when the decrease in pH is less, the cardiodepressant effect of thiopental may offset any deleterious effect of the drug on intracellular organelles such as mitochondria.

Topics: Adenosine Triphosphate; Animals; Coronary Circulation; Coronary Disease; Creatine Kinase; Hydrogen-Ion Concentration; Hypoxia; In Vitro Techniques; Mitochondria, Heart; Myocardium; Perfusion; Phosphocreatine; Rats; Rats, Inbred Strains; Thiopental

Acute myocardial ischaemia was induced in five greyhounds by ligation of the anterior descending branch of the left main coronary artery. Changes in oxygen availability and consumption in the ischaemic area in response to thiopentone 10 mg kg-1 were compared with corresponding changes in non-ischaemic myocardium supplied by the circumflex artery. Despite a 40% reduction in arterial pressure, there were no significant changes in the oxygen availability/consumption ratio in either normal or ischaemic areas.

Topics: Acute Disease; Animals; Blood Pressure; Coronary Circulation; Coronary Disease; Dipyridamole; Dogs; Halothane; Heart Rate; Lidoflazine; Oxygen Consumption; Thiopental

Thiopentone was administered as induction agent for general anesthesia to eight patients with stable ischemic heart disease; 6 mg/kg of the drug induced decrease in arterial blood pressure (-27%), systematic vascular resistance (-20%), stroke volume index (-14%), mean pulmonary arteriolar occlusion pressure (-15%) and left ventricular stroke work index (-38%), while heart rate increased by 10% and cardiac output remained unchanged. Total body oxygen consumption decreased by 30%. Myocardial oxygen consumption decreased by 39% with unchanged or decreased myocardial oxygen extraction and myocardial lactate uptake decreased by 40%. Arterial and coronary sinus hypoxanthine levels were unchanged and no ST-T-segment changes or dysrhythmias were recorded. In the present experimental setting, the results indicate that thiopentone substantially decreased myocardial oxygen requirements. In spite of the marked reduction in coronary perfusion, myocardial oxygen demand was matched by supply, myocardial dysoxia was not induced and cardiodepression was clinically negligible. Rate pressure product was a poor indicator of changes in myocardial oxygen consumption after thiopentone administration.

Topics: Aged; Anesthesia, General; Coronary Circulation; Coronary Disease; Depression, Chemical; Female; Heart; Hemodynamics; Humans; Male; Middle Aged; Myocardium; Oxygen Consumption; Thiopental

Topics: Carotid Artery Diseases; Carotid Artery, Internal; Coronary Disease; Endarterectomy; Humans; Hypothermia, Induced; Male; Middle Aged; Myocardial Revascularization; Thiopental

Topics: Adult; Aged; Alfaxalone Alfadolone Mixture; Anesthesia, Inhalation; Anesthesia, Intravenous; Anesthetics; Coronary Disease; Coronary Vessels; Etomidate; Fentanyl; Hemodynamics; Humans; Imidazoles; Middle Aged; Thiopental

Topics: Anesthesia, General; Animals; Capillaries; Cardiac Catheterization; Chloralose; Coronary Circulation; Coronary Disease; Coronary Vessels; Dogs; Female; Femoral Vein; Heparin; Injections, Intravenous; Ligation; Male; Methods; Perfusion; Postoperative Complications; Serum Albumin, Radio-Iodinated; Sutures; Thiopental; Transplantation, Autologous; Ventricular Fibrillation

Topics: Anesthesia, General; Animals; Atropine; Coronary Disease; Dogs; Electrocardiography; Gallamine Triethiodide; Halothane; Ligation; Preanesthetic Medication; Succinylcholine; Thiopental; Tubocurarine

Topics: Adolescent; Adult; Age Factors; Aged; Anesthesia, General; Arrhythmias, Cardiac; Benperidol; Bradycardia; Coronary Disease; Cysts; Electrocardiography; Halothane; Humans; Jaw Fractures; Lidocaine; Male; Methohexital; Middle Aged; Propanidid; Propranolol; Surgery, Oral; Tachycardia; Thiopental; Tooth Extraction

Topics: Administration, Intravenous; Anesthesia; Anesthesia, Intravenous; Anesthesiology; Coronary Disease; Diet; Dietary Fats; Ergocalciferols; Hypercholesterolemia; Rats; Research; Stupor; Thiopental

Topics: Animals; Blood Circulation; Cats; Cerebral Cortex; Coronary Disease; Coronary Vessels; Electric Stimulation; Electrocardiography; Ethers; Ganglionic Blockers; Hexamethonium Compounds; Methods; Thiopental