thiopental and Intervertebral-Disc-Displacement

The aim of this study was to investigate the influence of the premedication and the influence of the two barbiturates methohexital and thiopental on magnetically evoked compound muscle action potentials (magnet MEP) in humans.. 40 Patients (ASA-PS I-II) undergoing lumbar nucleotomy were included in this study after obtaining written informed consent. The study was approved by the local ethical committee. All patients were premedicated with 0.5 mg atropine, 25 mg promethazine and 50 mg pethidine. For induction of anaesthesia patients randomly received methohexital or thiopental by continuous infusion with increasing infusion rates every 15 seconds up to a minimal anaesthesia level in 15 minutes. Transcranial magnetic stimulation was delivered by the magstim 200 magnetic stimulator. Magnetic MEPs were recorded from the surface of the short abductor pollices muscle. MEP-examination was performed preoperatively, after premedication and every two minutes during the induction of anaesthesia. Every other two minutes the patients level of consciousness were assessed and documented. Statistical calculations were performed with the U-test.. No statistical differences were found for the mean induction time in the two groups. No statistical difference in amplitude and latency could be observed between the preoperative values and the values measured after premedication. During anaesthesia induction the amplitude decreased in both groups. In 25 of the 40 cases, the MEP disappeared completely before the patients fell asleep. The thiopental group showed a significantly lower incidence of MEP preservation (20%) compared to methohexital (50%).. Premedication with atropine, promethazine and pethidine has no influence on magnetic MEP. Methohexital allows the highest incidence of successful MEP recordings with sufficient anaesthesia. A success rate of only 50% even in cases without motorpathway affection makes the application of magnetic MEP an unreliable tool for intraoperative monitoring.

Topics: Adjuvants, Anesthesia; Adult; Aged; Anesthesia, Intravenous; Arousal; Atropine; Cerebral Cortex; Diskectomy; Electroencephalography; Electromagnetic Fields; Evoked Potentials, Motor; Female; Humans; Hypnotics and Sedatives; Injections, Intramuscular; Intervertebral Disc Displacement; Lumbar Vertebrae; Male; Meperidine; Methohexital; Middle Aged; Monitoring, Intraoperative; Preanesthetic Medication; Promethazine; Reaction Time; Thiopental

To observe whether the gas exchange is sufficient for the requirement of body when the patient was prone in position and pressed in the course of massage under intravenous anesthesia with sodium pentothal (SP) for the treatment of lumbar intervertebral disc prolapse.. The oxygen would not be given to the patients whose heart and lung functions were good during the course of anesthesia and massage, respiratory function and blood gas analysis were studied on 20 patients selected randomly.. Tidal volume was smaller and respiratory rate was faster than normal respiration. Saturation pulse oxygen was still normal in all patients. There were no significant changes in blood gas analysis before spinal injection and after massage (P > 0.05).. The pressing could attain the action of artificial respiration. The respiration pattern was similar to high frequency positive pressure ventilation. The action of vibration and diffusion had normal respiratory effect.

Topics: Adult; Anesthesia, Intravenous; Anesthetics, Intravenous; Female; Humans; Intervertebral Disc Displacement; Lumbar Vertebrae; Male; Massage; Middle Aged; Respiration, Artificial; Thiopental

The influence of four intravenous anesthetic agents on motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation (magnetic MEP) was examined in 77 subjects. The patients were anesthetized by a continuous intravenous infusion of one of the following anesthetic agents: propofol, etomidate, methohexital, or thiopental. Comparable anesthetic effects among the four agents were achieved by computing an infusion scheme for each drug. Infusion rates were increased slowly in a step-wise manner in order to reach minimal anesthetic blood concentrations within 15 minutes. During anesthesia induction, magnetic MEPs were recorded every 2 minutes from the abductor pollicis brevis muscle. The patient's level of consciousness was assessed and documented in the alternating minutes. A dose-related reduction of the MEP amplitudes was seen in all drug groups, while the latencies remained constant. Reduction of the amplitude was occasionally so prominent that the MEP was completely abolished before adequate anesthesia was achieved. MEPs were obtainable at the end of anesthesia induction in 14% of the propofol group (n = 22), 57% of the etomidate group (n = 21), 53% of the methohexital group (n = 19), and 20% of the thiopental group (n = 15). Propofol and thiopental showed significantly stronger suppression of MEP, when compared to etomidate (both P < 0.01) and to methohexital (P = 0.01 and 0.05, respectively). Etomidate was the least detrimental anesthetic agent for intraoperative monitoring of magnetic MEP. Nonetheless, the low incidence of 57% of preserved MEP in subjects without motor deficits indicated the inadequacy of this technique for intraoperative monitoring. More effective transcranial stimulation techniques are required for successful intraoperative MEP monitoring.

Topics: Adult; Aged; Anesthesia, Intravenous; Dose-Response Relationship, Drug; Electroencephalography; Electromagnetic Fields; Etomidate; Evoked Potentials; Female; Humans; Infusion Pumps; Intervertebral Disc Displacement; Male; Methohexital; Middle Aged; Monitoring, Intraoperative; Motor Cortex; Motor Endplate; Muscles; Propofol; Reaction Time; Thiopental

After injection of etomidate during surgery for herniation of an intervertebral disk an anaphylactoid reaction occurred. Generalized erythema, severe urticaria, and rise in heart rate and blood pressure drop were observed. After treatment with an antihistaminic and a corticosteroid the phenomenons completely disappeared within 45 minutes.

Topics: Alcuronium; Anaphylaxis; Anesthesia, Inhalation; Drug Interactions; Etomidate; Fentanyl; Halothane; Humans; Imidazoles; Injections, Intravenous; Intervertebral Disc Displacement; Male; Middle Aged; Nitrous Oxide; Thiopental