thiopental and Constriction--Pathologic

The authors studied the effects of thiopental on baseline airway tone in intact guinea pig tracheas using a preparation where the epithelial (inside) and serosal (outside) surfaces were isolated. Whole tracheas were excised, cannulated, and mounted in 50-ml tissue baths. The serosal and epithelial surfaces were perfused via separate circuits with Krebs-Henseleit solution. All data were expressed as a percent of constriction produced by 2 X 10(-6) M carbachol (a concentration that elicited a 90 + % of maximal constriction). Thiopental elicited a dose-dependent constriction in all 25 tracheas. Increases in tone were first seen at 10(-5) M (14.3 +/- 1.84%; mean +/- SEM) and reached a peak at 10(-3) M (29 +/- 3.16%; P less than .0001). Responses to thiopental were similar when the epithelium was removed, when thiopental was added to the inner perfusate, and when tracheas were pretreated with 10(-5) M pyrilamine. Constriction was entirely inhibited by pretreatment with indomethacin 10(-5) M. The authors conclude that thiopental, at concentrations in the clinical range, causes a reproducible dose-dependent constriction of guinea pig trachea. This effect is mediated by constrictor prostaglandins.

Topics: Animals; Constriction, Pathologic; Dose-Response Relationship, Drug; Guinea Pigs; In Vitro Techniques; Male; Thiopental; Trachea

The thiopentone sodium surge in plasma was investigated in 15 elderly surgical patients and 10 young adults during injection, over a period of 1 minute, of 4 mg of anaesthetic per kg of fat-free body weight (in 18 patients), and 5 mg per kg of fat-free body weight (7 patients). In keeping with prolonged circulation time in old age, thiopentone sodium reached the sampling site faster in the younger patients than it did in the older patients. In the majority of cases, thiopentone sodium concentrations in plasma reached a maximum of between 60 and 80 micrograms/ml. Mean thiopentone sodium concentrations in the older patients were 10% higher, but here values differed so widely that this result must be regarded as coincidental. It was, accordingly, impossible to establish any statistically verifiable differences between young and old patients by estimating the volume of thiopentone sodium distribution shortly after the end of injection. Plasma protein binding, 85% on average, with extremes ranging from 79% to 89% did not depend on thiopentone concentration or age. In the group of patients studied, it was not possible to confirm statistically that the plasma protein concentration influenced the rate of binding. Dosage according to fat-free body weight did not diminish inter-individual differences in plasma concentration-time profiles.

Topics: Adult; Age Factors; Aged; Anesthesia, General; Carotid Artery Diseases; Constriction, Pathologic; Dose-Response Relationship, Drug; Hearing Loss; Hearing Loss, Conductive; Humans; Protein Binding; Thiopental

We present an extremely rare case of an arteriovenous malformation (AVM) in the territory of the middle cerebral artery, the main trunk of which was occluded asymptomatically. Immediately after an uneventful excision of the entire AVM, massive brain swelling occurred unexpectedly and was treated successfully with high dose barbiturate therapy associated with other standard measures of controlling increased intracranial pressure. The underlying pathophysiological mechanisms leading to the massive intraoperative brain swelling in this case are discussed.

Topics: Adult; Brain Edema; Cerebral Angiography; Cerebral Arterial Diseases; Cerebral Hemorrhage; Cerebral Infarction; Constriction, Pathologic; Humans; Intracranial Arteriovenous Malformations; Intracranial Pressure; Male; Microsurgery; Postoperative Complications; Thiopental

The venous plasma concentration-time profiles of thiopentone were measured simultaneously over the first 30-40 min after induction of anaesthesia, in blood obtained from an arm vein and a vein in the foot, in nine healthy full-term women undergoing Caesarean section. Patients were tilted laterally to the left by from 8 to 18 degrees during the procedure. In all but two of the patients, the profiles from the arm and foot were virtually identical, suggesting that aortocaval compression was absent or insignificant. Therefore, the large intersubject variability in volume of distribution of thiopentone at Caesarean section is unlikely to be the result of aortocaval compression.

Topics: Adult; Aorta, Abdominal; Cesarean Section; Constriction, Pathologic; Female; Humans; Posture; Pregnancy; Thiopental; Vena Cava, Inferior

Topics: Aged; Analgesia; Anesthesia; Anesthesia and Analgesia; Anesthesiology; Constriction, Pathologic; Humans; Lidocaine; Pain Management; Pylorus; Thiopental