thiamylal and Hypertension

High concentration of isoflurane often induces not only tachycardia but also hypertension during induction of anesthesia and causes further hyperdynamic changes after tracheal intubation.. Forty patients, ASA physical status I, were randomly assigned to receive 4% or 2.5% isoflurane. Anesthesia was induced with thiamylal and vecuronium followed by mask ventilation with 0.5% isoflurane in oxygen. Isoflurane concentration was gradually increased to 4% or 2.5% in 2 min and the trachea was intubated after 3 min. Systolic blood pressure (SBP) and heart rate (HR) were recorded every minute from induction of anesthesia.. Mask ventilation with isoflurane induced a significant increase in HR in both groups, but the HR just before intubation was significantly lower in the 2.5% group than in the 4% group. SBP was significantly decreased in the 2.5% group, but a transient increase was seen in the 4% group. Tracheal intubation induced a marked increase in HR in both groups, but the HR was significantly lower in the 2.5% group than in the 4% group (115 +/- 14 and 130 +/- 18 beats x min(-1), respectively; P < 0.01). SBPs just after intubation were 166 +/- 24 and 154 +/- 20 mmHg in the 4% and 2.5% groups, respectively. The difference between the groups was not significant, but the patients in whom the SBP increased more than 180 mmHg were significantly fewer in the 2.5% group than in the 4% group (P < 0.05).. Reduction of the isoflurane concentration from 4% to 2.5% during induction of anesthesia made the circulation stable, and decreased the incidence of excessive tachycardia and hypertension after tracheal intubation.

Topics: Adult; Anesthesia, Inhalation; Blood Pressure; Female; Heart Rate; Hemodynamics; Humans; Hypertension; Intubation, Intratracheal; Isoflurane; Male; Middle Aged; Tachycardia; Thiamylal; Vecuronium Bromide

To compare the effects of propofol and thiamylal on the hyperdynamic circulatory response caused by a rapid increase in isoflurane concentration.. Prospective, randomized, double-blind study.. Operating rooms of a university hospital.. 30 ASA physical status I adult patients scheduled for elective surgery with general anesthesia.. Patients were anesthetized with either propofol 2 mg/kg (propofol group, n = 15) or thiamylal 4 mg/kg (thiamylal group, n = 15). Two minutes after anesthesia induction, the inspired isoflurane concentration was rapidly increased from 0.5% to 5% and maintained for 5 minutes.. Mean arterial pressure significantly increased after the increase in isoflurane concentration in the thiamylal group, but it did not change in the propofol group. The isoflurane-induced increase in rate-pressure product was significantly greater in the thiamylal group than in the propofol group.. Propofol induction of anesthesia more effectively attenuates the circulatory responses to a sudden increase in isoflurane concentration than does thiamylal.

Topics: Adult; Analysis of Variance; Anesthetics, Inhalation; Anesthetics, Intravenous; Dose-Response Relationship, Drug; Double-Blind Method; Female; Humans; Hypertension; Isoflurane; Male; Middle Aged; Propofol; Thiamylal; Time Factors; Treatment Outcome

We examined the circulatory changes after intravenous thiamylal with additional injection of thiamylal 1 minute before intubation and after propofol at the time of anesthetic induction and endotracheal intubation. Sixty ASA I or II patients were studied after the institutional and informed consents. We compared the following three groups. Group I (n = 20): Anesthesia was induced with thiamylal 5 mg.kg-1 and intubation with the aid of vecuronium 0.1 mg.kg-1. Group II (n = 20): Anesthesia was induced with thiamylal 3 mg.kg-1 and vecuronium 0.1 mg.kg-1. One minute before the intubation, the patients received additional thiamylal 4 mg.kg-1. Group III (n = 20): Anesthesia was induced with propofol 2.5 mg.kg-1 and intubation was performed with the aid of vecuronium 0.1 mg.kg-1. We examined the systolic, diastolic and mean blood pressures, heart rate, and rate pressure product (RPP) in the three groups. The examinations were performed before and after induction, soon after intubation, and every one minute after intubation for 5 minutes. After the endotracheal intubation, the systolic blood pressure and heart rate increased in Group I. But the systolic and diastolic pressures were significantly more stable in Group II and Group III. The change of the RPP was slight and most stable in Group II compared with the other two groups. We conclude that additional injection of thiamylal 4 mg.kg-1 following induction of anesthesia with thyamylal 3 mg.kg-1 1 minute before endotracheal intubation is an effective method for minimizing the increase in blood pressure and circulatory changes at the time of rapid induction of anesthesia and endotracheal intubation.

Topics: Adjuvants, Anesthesia; Adult; Aged; Anesthesia, General; Anesthetics, Intravenous; Female; Humans; Hypertension; Intubation, Intratracheal; Male; Middle Aged; Propofol; Thiamylal

Bolus administration of propofol for induction causes hypotension, especially in elderly hypertensive patient. Carefully titrated infusion of propofol minimizes adverse effects, such as hypotension, and permits a rapid recovery of its central effects. The objective of this study was to investigate the effect of a manually controlled infusion scheme of propofol and alfentanil mixture on hemodynamic stability during induction and endotracheal intubation for hypertensive patient. At the same time, the effectiveness of this scheme was compared with two other induction regimens (thiamylal or nifedipine plus thiamylal).. Sixty hypertensive patients undergoing orthopedic surgery were randomized into 3 groups (n = 20 per each group), None of the patients received premedication. Anesthesia was induced in group 1 (G1) with alfentanil 10 micrograms/kg. 30 s later, manual infusion of a mixture of propofol (10-12 mg/kg/h) and alfentanil (25 micrograms/kg/h) was performed for 2 min, followed by atracurium (5 mg) and propofol (1-1.5 mg/kg) as a bolus induction dose over 20 s, and then Suxamethonium (1.5 mg/kg) at 30-40 s later. Intubation was done while giving a continuous infusion of propofol and alfentanil. After intubation, the infusion rate was adjusted according to the blood pressure (BP) variation. Group 2 patients (G2) were induced with fentanyl (2 micrograms/kg), thiamylal (4-5 mg/kg), atracurium (5 mg) and succinylcholine (1.5 mg/kg). Induction of anesthesia in group 3 patients (G3) was the same as for G2, with additional sublingual nifedipine (1/2 capsule) 10 min prior to induction. Extra bolus dose of propofol (20 mg) or thiamylal (20 mg) was given at every 15 s if the systolic BP was still higher than 160 mmHg after induction by the above 3 regimens. The radial arterial pressure and electrocardiogram were continuously recorded for evaluation of hemodynamic changes.. Post-intubation peak mean arterial pressure (MAP) in G1 and G3 were below to awake baseline values, while MAP of G2 was significantly higher than over awake baseline level (p < 0.001). The lowest MAP of G3 at post-intubation period before surgical stimulation were significantly lower than those of G1 and G2 (p < 0.001). Peak tachycardiac response to intubation in G2 was significantly higher than G1 (p < 0.05). After intubation, the peak rate pressure product were significantly higher in G2 compared with that in G1 (p < 0.05) and G3 (p < 0.001).. The proposed manual infusion scheme of propofol and alfentanil mixture performed during induction and intubation attenuated the subsequent peak pressor response to incubation and reduced the hypotensive effect, in comparison to thiamylal or thiamylal plus nifedipine treatment, during post-intubation period. The same infusion scheme also attenuated the tachycardiac response to intubation.

Topics: Aged; Alfentanil; Anesthetics, Intravenous; Blood Pressure; Female; Heart Rate; Humans; Hypertension; Intubation, Intratracheal; Male; Middle Aged; Nifedipine; Propofol; Thiamylal

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.

Topics: Acid-Base Equilibrium; Adaptation, Physiological; Adult; Anesthesia, Inhalation; Anesthesia, Intravenous; Anesthesia, Obstetrical; Apgar Score; Cesarean Section; Female; Fetal Blood; Humans; Hypertension; Infant, Newborn; Intubation, Intratracheal; Isoflurane; Laryngoscopy; Pregnancy; Propofol; Thiamylal

Topics: Accidents, Traffic; Adolescent; Anesthesia; Aorta, Thoracic; Enflurane; Humans; Hypertension; Intracranial Pressure; Male; Nitroprusside; Splenectomy; Thiamylal

Topics: Anesthesia, General; Animals; Blood Pressure; Cardiovascular System; Catalepsy; Cats; Central Nervous System; Columbidae; Cyclohexanes; Dogs; Drug Synergism; Guinea Pigs; Haplorhini; Heart; Heart Rate; Humans; Hypertension; Mice; Motor Activity; Norepinephrine; Pentylenetetrazole; Phencyclidine; Phenethylamines; Rabbits; Rats; Seizures; Species Specificity; Tachycardia; Thiamylal