PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “THIAMYLAL”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 91 records · Page 5Linked to original sources
PubMed1975

Effects of xylazine and acetylpromazine upon induced ventricular fibrillation in dogs anesthetized with thiamylal and halothane.

Ventricular arryhythmias including ventricular fibrillation were produced with epinephrine in dogs induced to an anesthetic state with thiamylal and maintained with halothane. In dogs given (premedicated) xylazine 20 minutes prior to anesthesia, ventricular arrhythmias, including ventricular fibrillation, were induced with much smaller doses of epinephrine than in nonpremedicated dogs. Dogs premedicated with acetylpromazine 20 minutes prior to anesthesia with thiamylal and halothane displayed protection from epinephrine-induced arrhythmias. Caution is advised from using xylazine in the presence of halothane if epinephrine is to be administered.

Anesthesia↗
PubMed1988

Pharmacokinetics of thiamylal in cats.

Pharmacokinetics of thiamylal were determined after 13.2 mg of thiamylal/kg of body weight was administered IV to 6 healthy cats. Blood samples were obtained for 12 hours. Disposition of thiamylal best conformed to 2 multicompartmental models, a 2-compartment (n = 1) and a 3-compartment (n = 5) open pharmacokinetic model. The pharmacokinetic values were calculated for the overall best-fitted model, a mixed 2- and 3-compartmental model. The first or rapid distribution half-life was 1.91 minutes and a second, or slower, distribution half-life was 26.51 minutes. The elimination half-life was 14.34 hours. The apparent volume of distribution was 3.61 +/- 1.8463 L/kg, whereas the apparent volume of the central compartment was 0.46 +/- 0.2034 L/kg, and the total clearance was 0.135 +/- 0.0616 L/kg/h.

Animals↗
PubMed1975

Arrhythmias in dogs associated with epinephrine and thiamylal anesthesia.

Sinus tachycardia bigeminy, ventricular rhythm, ventricular tachycardia, and ventricular fibrillation are produced by relatively small intravenous doses of epinephrine in nonanesthetized dogs and in dogs anesthetized with thiamylal sodium. Origin of the abnormal beat in coupled bigeminal rhythms generated from the bundle o of His or above. Increases in arterial blood pressure may predispose to arrhythmia formation during thiamylal anesthesia.

Anesthesia, Intravenous↗
PubMed1983

Arrhythmogenicity of dopamine, dobutamine, and epinephrine in thiamylal-halothane anesthetized dogs.

The arrhythmogenicity of epinephrine, dopamine, and dobutamine, administered by constant-rate infusion, was determined in vagotomized and nonvagotomized thiamylal-halothane anesthetized dogs. Electrocardiograms and atrioventricular bundle electrograms revealed the development of atrial, junctional, and ventricular arrhythmias. The 3 drugs produced atrial arrhythmias at dosages smaller than those required to produce ventricular arrhythmias. The mean dosages (microgram/kg-1/min-1) required to produce ventricular arrhythmias on duplicate trials in vagotomized dogs were for epinephrine, 0.6 +/- 0.2; dopamine, 22.8 +/- 14.8; and dobutamine, 11.6 +/- 5.2. The corresponding doses for nonvagotomized dogs were for epinephrine, 0.8 +/- 0.3; dopamine, 35.3 +/- 13.5; and dobutamine, 21.9 +/- 13.9. Most ventricular arrhythmias originated from a single focus in the left ventricle. Heart rate and blood pressure were significantly increased immediately before ventricular arrhythmia appeared. We conclude that epinephrine, dopamine, and dobutamine are capable of producing cardiac arrhythmias in vagotomized and nonvagotomized thiamylal-halothane anesthetized dogs and that bilateral vagotomy decreases the dosage of epinephrine, dopamine, and dobutamine required to produce cardiac arrhythmias.

Anesthesia, Inhalation↗
PubMed1993

Effect of hypercapnia on the arrhythmogenic dose of epinephrine in horses anesthetized with guaifenesin, thiamylal sodium, and halothane.

The effect of hypercapnia on the arrhythmogenic dose of epinephrine (ADE) was investigated in 14 horses. Anesthesia was induced with guaifenesin and thiamylal sodium and was maintained at an endtidal halothane concentration between 0.86 and 0.92%. Base-apex ECG, cardiac output, and facial artery blood pressure were measured and recorded. The ADE was determined at normocapnia (arterial partial pressure of carbon dioxide [PaCO2] = 35 to 45 mm of Hg), at hypercapnia (PaCO2 = 70 to 80 mm of Hg), and after return to normocapnia. Epinephrine was infused at arithmetically spaced increasing rates (initial rate = 0.25 micrograms/kg of body weight/min) for a maximum of 10 minutes. The ADE was defined as the lowest epinephrine infusion rate, to the nearest 0.25 micrograms/kg/min, at which 4 premature ventricular complexes occurred in a 15-second period. The ADE (mean +/- SD) during hypercapnia (1.04 +/- 0.23 micrograms/kg/min) was significantly (P < 0.05) less than the ADE at normocapnia (1.35 +/- 0.38 micrograms/kg/min), whereas the ADE after return to normocapnia (1.17 +/- 0.22 micrograms/kg/min) was not significantly different from those during normocapnia or hypercapnia. Baseline systolic and diastolic arterial pressures and cardiac output decreased after return to normocapnia. Significant differences were not found in arterial partial pressure of O2 (PaO2) or in base excess during the experiment. Two horses developed ventricular fibrillation and died during normocapnic determinations of ADE. Hypercapnia was associated with an increased risk of developing ventricular arrhythmias in horses anesthetized with guaifenesin, thiamylal sodium, and halothane.

Anesthesia↗
PubMed1985

Reduction of the slow inward current of isolated rat ventricular cells by thiamylal and halothane.

The barbiturates and halothane exert a negative inotropic effect on the myocardium. A reduction in the slow inward current, carried mainly by calcium ions, is an important factor for the underlying mechanism because the calcium current during the action potential provides the calcium ions for accompanying contraction, supplies Ca ions to the sarcoplasmic reticulum for subsequent contractions, and induces Ca release from the store site. It has been suggested that reduction in the slow inward current caused by anesthetics is indicated by depression of the slow action potential of the partially depolarized myocardium. In order to assess directly the effect of anesthetics on the slow inward current, we carried out voltage clamp experiments with single isolated rat ventricular cells obtained by an enzymatic dissociation method. Thiamylal (10(-4) mol . l-1) and halothane (1%) decreased the slow inward current to 60 +/- 5% (mean +/- s.d., n = 8) and to 65 +/- 10% (mean +/- s.d., n = 8) of the control value, respectively, without changing the configuration of the current-voltage curve. The results provide further evidence for anesthetic reduction of the slow inward current of the myocardium, and suggest that the negative inotropic effect is at least partly due to the reduction in that current.

Action Potentials↗
PubMed1995

Intravenous propofol vs thiamylal-isoflurane for caesarean section, comparative maternal and neonatal effects.

Several studies on propofol (Diprivan) for induction of anaesthesia during caesarean section have demonstrated its safety, however, it safety during maintenance of anaesthesia is not yet fully evaluated. The present study was undertaken to compare the maternal and neonatal effects of propofol or isoflurane in 74 term parturients undergoing primary or repeat caesarean section. Patients were randomly assigned to two groups, propofol group (n = 37) received propofol 1.5-2.5 mg.kg-1 for induction followed by a continuous infusion of propofol of 0.05-0.2 mg.kg-1.min-1. The isoflurane group (n = 37) received thiamylal 3-4mg.kg-1 for induction followed by isoflurane 0.25-0.75% for maintenance. All patients had rapid sequence induction using succinylcholine and endotracheal intubation, 50% N2O and O2 were used in all patients until delivery. After delivery N2O concentration was increased to 67% and intravenous butorphanol (Stadol) was given as needed. Patients in the propofol group had less hypertension after intubation (P < 0.05) and this was also of shorter duration compared to patients in the isoflurane group (5 min vs 10 min respectively). Maternal blood loss as well as intraoperative awareness and recovery time did not differ significantly between the two groups. Neonatal status as ascertained by Apgar scores, cord acid base status and the neurological and adaptive capacity scores (NACS) was equally good in both groups. It is concluded that propofol used for induction and maintenance of anaesthesia is a safe alternative to thiamylal/isoflurane for patients undergoing caesarean section and is associated with less hypertensive response during laryngoscopy and intubation.

Acid-Base Equilibrium↗
PubMed2005

[A survival case of tetanus complicated with disseminated intravascular coagulation syndrome in the elderly, rescued by mechanical ventilation and administration of thiamylal].

A 78-year-old Japanese female was admitted to our hospital because of headache. Trismus, opisthotonus and convulsion appeared in the early morning on the second hospital day. She was diagnosed as tetanus based on these symptoms and the history of trauma on her left hand 6 days ago. A piece of bamboo was extracted from her left hand. However, Clostridium tetani was not identified. Thiamylal and mechanical ventilation were initiated combined with Pancronium, Diazepam and tetanus immune globulin. Gabexate Mesilate was also added for disseminated intravascular coagulation syndrome probably associated with rhabdomyolysis. By these treatments, she was healed leaving only a disuse syndrome of her limbs.

Aged↗
PubMedDate not supplied

Determination of optically active thiopental, thiamylal, and their metabolites in human urine.

Methods involving solvent extraction and gas-liquid chromatography have been developed for quantitative determination of certain thiobarbiturates and their major metabolites in urine. The structures of the metabolites identified were confirmed by the use of gas chromatography/mass spectrometry and 13C-nuclear magnetic resonance spectroscopy. The present analytic methods were applied to the quantitative determination of (R)-(+)- and (S)-(-)-thiopental as well as (R)-(+)- and (S)-(-)-thiamylal and their major metabolites excreted in human urine. Minor metabolites were isolated and identified.

Chromatography, Gas↗
PubMed1988

Comparison of cardiopulmonary effects of isoflurane and halothane after atropine-guaifenesin-thiamylal anesthesia for rumenotomy in steers.

Cardiopulmonary effects were assessed in 12 yearling steers anesthetized with guaifenesin and thiamylal sodium, intubated, and allowed to breathe isoflurane or halothane in oxygen spontaneously. Light surgical anesthesia, determined using eye position as a clinical indication of anesthetic depth, was maintained during surgical placement of a rumen cannula. Heart rate and respiratory rate were measured while the steers were standing quietly (baseline). Atropine (0.06 mg/kg of body weight, IM) was given after baseline measurements were taken. Heart rate, respiratory rate, arterial blood pressures, pHa, PaCO2, PaO2, arterial [HCO3-], esophageal temperature, and end-tidal anesthetic concentration were measured every 15 minutes for 90 minutes after induction of anesthesia. Mean heart rate increased significantly (P less than 0.05) above baseline in the isoflurane group at 15 and 30 minutes. Mean respiratory rate increased significantly (P less than 0.05) above baseline in the halothane group at 45 minutes. At 45 minutes, mean respiratory rate was lower (P less than 0.05) in the isoflurane group, compared with that in the halothane group. Mean values for arterial blood pressures and arterial gases were similar for both agents at comparable times. Mean end-tidal isoflurane concentrations were less than mean end-tidal halothane concentrations at each comparable time during maintenance of similar anesthetic depth. Maintenance of anesthesia with isoflurane resulted in higher heart rates and lower respiratory rates, compared with maintenance of anesthesia with halothane in these steers.

Anesthesia, General↗
PubMed1985

Comparative pharmacokinetics and anesthetic effects of methohexital, pentobarbital, thiamylal, and thiopental in Greyhound dogs and non-Greyhound, mixed-breed dogs.

Pharmacokinetics and duration of anesthesia of methohexital, pentobarbital, thiamylal, and thiopental in Greyhound and non-Greyhound, mixed-breed dogs were compared. In all dogs evaluated, pentobarbital induced the longest duration of anesthesia and methohexital induced the shortest duration. Pharmacokinetics of pentobarbital and methohexital were similar in both groups of dogs. Thiobarbiturates induced longer anesthetic effects in Greyhound dogs than in mixed-breed dogs. Plasma thiobarbiturate concentrations remained above normal longer in Greyhound dogs than in mixed-breed dogs. Disposition of thiobarbiturates in Greyhound dogs was characterized by nonlinearity from 45 minutes to 8 hours after dosing.

Anesthesia, General↗
PubMed1983

Fatal interaction between thiamylal sodium and a proprietary antidiarrheal preparation in the dog.

A drug interaction involving thiamylal sodium and a proprietary antidiarrheal preparation caused fatal ventricular fibrillation in a dog. Trials involving 4 dogs were conducted to recreate the interaction, and 1 of the 4 dogs died after ventricular fibrillation developed. The nature of the interaction was hypothesized to be mediated through the anticholinergic drug diphemanil methylsulfate, producing an autonomic imbalance.

Anesthetics↗
PubMedDate not supplied

Unintentional epidural administration of thiamylal. Case report.

BACKGROUND AND OBJECTIVES: A 36-year-old woman was scheduled for surgery of bicornuate uterus under epidural anesthesia. METHODS: As a test dose, 3 mL 2.5% thiamylal was injected unintentionally through the epidural catheter instead of 1.5% lidocaine with 15 micrograms epinephrine. RESULTS: Immediately the patient complained of burning pain in the low back area. Administrations of 10 mL 2% lidocaine without epinephrine and 10 mL normal saline containing hydrocortisone 100 mg were performed through the epidural catheter. CONCLUSIONS: The patient recovered without permanent neurologic sequelae.

Accidents↗
PubMed1993

Effects of atropine on the arrhythmogenic dose of dobutamine in xylazine-thiamylal-halothane-anesthetized horses.

We investigated the influence of parasympathetic tone on the arrhythmogenic dose of dobutamine in horses premedicated with xylazine, anesthetized with guaifenesin and thiamylal, and maintained on halothane in oxygen. Six horses were used in 12 randomized trials. In each trial, after end-tidal halothane concentration was stabilized at 1.1% (1.25 times minimum alveolar concentration [MAC]) in oxygen, either saline solution (0.02 ml/kg of body weight) or atropine (0.04 mg/kg) was administered IV. Five minutes later, dobutamine infusion was started at dosage of 2.5 micrograms/kg/min, IV. The dobutamine infusion was continued for 10 minutes, or until 4 or more premature ventricular complexes occurred within 15 seconds, or sustained narrow-complex tachyarrhythmia clearly not sinus in nature occurred. If the criteria for termination were not met, dobutamine infusion was increased by 2.5 micrograms/kg/min, after the hemodynamic variables had returned to baseline. The horses were allowed to recover, and were rested for at least 1 week before the second trial. The arrhythmogenic dose of dobutamine was calculated by multiplying the infusion rate by the elapsed time into infusion when arrhythmia occurred. There was significant difference between the arrhythmogenic dose of dobutamine (ADD) in saline-treated horses (mean +/- SEM, ADD = 105.6 +/- 16.3 micrograms/kg) and atropinized horses (ADD = 36.2 +/- 8.7 micrograms/kg). There were no differences in the prearrhythmia or immediate postarrhythmia ventricular heart rate (HR) or systolic (SAP), diastolic (DAP), or mean (MAP) arterial pressures between treated and control groups. The change in hemodynamic variables from prearrhythmia to immediate postarrhythmia formation was not different between the 2 groups. (ABSTRACT TRUNCATED AT 250 WORDS)

Anesthesia, General↗
PubMed1977

Measurement of thiamylal and thiopental in plasma by electron capture and flame photometric gas-liquid chromatography.

We describe an isothermal gas-liquid chromatographic procedure developed for measuring thiamylal and thiopental in plasma. The unchanged drug is extracted into ethyl acetate from acidified plasma, together with an internal standard. The solvent is removed, the residue methylated, aliquots, diluted with benzene, are injected into a 183-cm gas-liquid chromatographic column containing 3% OV-17. Sensitivity of detection is in the nanogram to picogram range.

Chromatography, Gas↗
PubMed1977

Physiologic changes in the dog anesthetized with thiamylal and enflurane.

Enflurane anesthesia with thiamylal induction in the dog produced only slight, statistically insignificant, changes in the heart rate and the mean systemic blood pressure. A significant depression of the respiratory rate with an associated significant increase in the arterial partial pressure of CO2 was produced, accompanied by a decrease in the blood pH. Progressive drop of the body temperature occurred throughout anesthesia. Significant hematologic changes included a reduction in the packed cell volume and the erythrocyte and leukocyte counts. The only significant change in the blood chemistry was an increase in alkaline phosphatase at 24 and 48 hours after induction of anesthesia.

Alkaline Phosphatase↗