thiopental and Paralysis

Awareness under anesthesia can be a frightening experience for patients receiving electroconvulsive therapy (ECT).. We present a 19-year-old, 62-kg, bipolar woman who was prescribed right unilateral ECT for a treatment-refractory major depressive episode. Her premedication comprised thiopentone sodium (200 mg) and succinylcholine (30 mg). She received 3 treatments uneventfully. A day after the fourth treatment, she described her awareness of paralysis during the last procedure and refused further treatment despite the marked improvement that had resulted with ECT.. Electroconvulsive therapy is more usually administered with bilateral than with unilateral electrode placement. During ECT, awareness under anesthesia and recall of paralysis (resulting from inadequate doses of anesthesia and/or premature administration of the muscle relaxant) may be more common than is generally realized but may not be reported by patients because bilateral ECT tends to obliterate the memory of the ECT procedure. If this is true, unilateral nondominant ECT, which is relatively memory sparing, may increase the chance of recollection of paralysis when narcosis under anesthesia is incomplete. Careful clinical assessment and monitoring of the depth of anesthesia using the bispectral index can minimize this risk of awareness under anesthesia.

Topics: Adult; Anesthetics, Intravenous; Awareness; Dominance, Cerebral; Electroconvulsive Therapy; Female; Humans; Mental Recall; Paralysis; Risk Factors; Succinylcholine; Thiopental

To assess the dose-dependent effect of low concentrations of isoflurane on respiratory mechanics in normal subjects.. We studied 12 non-premedicated ASA I patients scheduled for lower abdominal or extremity surgery. After thiopental 5-7 mg*kg(-1) iv and succinylcholine 1 mg x kg(-1) iv, the trachea was intubated and an esophageal balloon was placed optimally by the occlusion test. After introduction of N(2)O and muscle paralysis with vecuronium, we studied 0, 0.6, 0.9 and 1.2% isoflurane. We recorded flow (F), airway opening and esophageal pressures. Signals were amplified, filtered, sampled at 100 Hz, and then fed in a 12-bit analogue-digital converter in a personal computer. Data were collected and analyzed using LABDAT and ANADAT software. Signals were acquired for 60-90 sec during mechanical ventilation (10 mL x kg(-1), 10 breaths x min(-1), I:E ratio 1:2). We estimated respiratory system (RS), lung (L) and chest wall (W) dynamic elastance (E) and resistance (R) by P(t) = EV(T)(t) + RF(t) + K, where t is time, V(T) tidal volume from integration of F, and K an estimation of end-expiratory pressure. ANOVA was used for comparing the basal state with the three concentrations.. E and R were statistically lower at 0.6, 0.9 and 1.2% compared to basal values for RS, L and W. Concentrations equal to or higher than 0.6% did not further change respiratory mechanics, except for E(L1.2) compared to E(L0.6,) 12.37 +/- 5.72 and 13.52 +/- 5.64 cm H(2)O.L(-1), respectively.. Isoflurane concentrations between 0.6-1.2% are not associated to a dose-dependent effect on respiratory mechanics.

Topics: Analysis of Variance; Anesthesia, General; Anesthetics, Inhalation; Anesthetics, Intravenous; Dose-Response Relationship, Drug; Humans; Isoflurane; Neuromuscular Depolarizing Agents; Paralysis; Respiratory Mechanics; Succinylcholine; Thiopental; Vecuronium Bromide

Topics: Connecticut; Conversion Disorder; History, 20th Century; Humans; Paralysis; Thiopental

Spinal cord ischemia and resultant paraplegia are devastating sequelae in up to 40% of patients undergoing repair of thoracoabdominal aneurysms. We investigated the effect of intrathecal tetracaine on the neurological sequelae of spinal cord ischemia and reperfusion with aortic occlusion. Cocaine-derived anesthetics (lidocaine and its analogues) have been shown to decrease neuronal cell metabolism and also have specific neuronal membrane stabilizing effects. New Zealand white rabbits were anesthetized and spinal cord ischemia was then induced by infrarenal aortic occlusion. Animals were divided into six treatment groups. Tetracaine (groups 2 and 4) or normal saline solution (group 5) was administered intrathecally before aortic cross-clamping. Groups 1 and 3 functioned as controls. Group 6 animals received intravenous thiopental. Rabbits were classified as either neurologically normal or injured (paralyzed or paretic). Among controls, 25 minutes of aortic occlusion produced varied neurological sequelae (group 1, 3/6 injured, 50%) whereas 30 minutes resulted in more consistent injury (group 3, 5/6 injured, 83%). All rabbits that received intrathecal saline solution were paralyzed (group 5, 4/4 injured, 100%). Animals treated with intrathecal tetracaine and aortic occlusion of 30 minutes (group 4) showed significantly better preservation of neurological function (6/7 normal, 86%) than controls and saline-treated animals (groups 3 and 5). All animals treated with intrathecal tetracaine and aortic occlusion for 25 minutes (group 2) showed no signs of injury (5/5 normal, 100%), but this was not significant versus controls (group 1). Intravenous thiopental (group 6, 5/5 injured, 100%) had no beneficial effect. Intrathecal tetracaine significantly and dramatically abrogated the neurological injury secondary to spinal cord ischemia and reperfusion after aortic occlusion at 30 minutes in the rabbit model.

Topics: Animals; Aorta; Constriction; Injections, Intravenous; Injections, Spinal; Ischemia; Paralysis; Rabbits; Reperfusion Injury; Spinal Cord; Tetracaine; Thiopental

Transmembrane potentials of the respiratory laryngeal motoneurons were recorded in decerebrate, vagotomized and paralyzed cats. Twenty inspiratory and thirteen postinspiratory neurons were identified. Periodic membrane potential (MP) fluctuations as well as patterns of postsynaptic potentials (PSPs) were characterized in each type of neurons by measuring the input resistance and injecting Cl- to reverse inhibitory PSPs. On the basis of PSP patterns, two subtypes of inspiratory neurons could be distinguished. Thiopental (2-3 mg/kg, i.v.) produced depolarization together with reduction of firing in most laryngeal neurons. Excitatory and inhibitory PSPs were both depressed and MP fluctuations became smaller in each phase of the respiratory cycle. Elevation of the firing threshold and separation of IS-SD spikes often occurred after thiopental. These results suggest that thiopental depresses the laryngeal motoneuron through inhibition of synaptic transmission and of spike generation.

Topics: Animals; Cats; Decerebrate State; Laryngeal Nerves; Membrane Potentials; Motor Neurons; Paralysis; Respiratory Center; Thiopental; Vagotomy; Vagus Nerve

Topics: Adolescent; Anesthesia, Intravenous; Female; Humans; Paralysis; Radial Nerve; Thiopental

Topics: Animals; Drug Interactions; Enzyme Induction; Female; Hexobarbital; Mice; Mice, Inbred C57BL; Mice, Inbred DBA; Mixed Function Oxygenases; Oxidoreductases; Ozone; Paralysis; Pentobarbital; Sleep; Thiopental; Zoxazolamine

The dose-response and plasma concentration-response relationships for pancuronium in man were studied during its intravenous administration to eight patients at a rate of 1.62 microgram/kg/min. The (log) dose-response relationships resulted in a sigmoid curve that was linear in its central range. At 20, 50 and 80 per cent paralysis the cumulative dosages (mean +/- SEM) were 0.04 (+/- 0.01), 0.06 (+/- 0.01), and 0.08 (+/- 0.02) mg/kg, respectively. Administration of pancuronium, 56 microgram/kg, to another 12 patients at a more rapid rate resulted in a maximum intensity of blockade of more than 50 per cent. The (log) plasma concentration-response curve was not parallel to the dose-response curve, with mean (+/- SEM) concentrations at 20, 50 and 80 per cent paralysis of 0.21 (+/- 0.04), 0.25 (+/- 0.04), and 0.30 (+/- 0.04) microgram/ml, respectively during the onset of paralysis. Following cessation of the infusion, plasma concentrations of pancuronium were usually lower for the same intensity of paralysis. Using data for the entire response range during recovery from paralysis, the mean effective plasma concentration of pancuronium for a 50 per cent response was 0.20 microgram/ml. Recovery from blockade to 95 per cent paralysis (5 per cent of control twitch height) was associated with a plasma concentration of 0.25 microgram/ml, a value in agreement with plasma concentrations obtained following a single bolus administration of pancuronium, 6 mg, to 30 patients. For 27 patients the rate of decline of paralysis from 80 to 20 per cent showed a highly statistically significant relationship to the apparent rate of decline in the plasma concentrations of pancuronium.

Topics: Adult; Aged; Dose-Response Relationship, Drug; Female; Humans; Injections, Intravenous; Kinetics; Male; Middle Aged; Pancuronium; Paralysis; Phenoperidine; Thiopental; Time Factors

The protective effect of thiopental on neurological lesions provoked by cerebral anoxie was studied in the monkey. Cerebral ischemia was induced by a cervical tourniquet applied for a period of 16 minutes. A control series of 10 animals received only the normal resuscitation. A series of 27 monkeys received either 90 mg/kg of thiopental at 5, 10, 15, 30 or 60 minutes following ischemia, or 120 mg/kg at the 30th or 60th minute. One third of the dose was administered within 5 minutes and the rest during the following 55 minutes. The results shows that the prevention, by thiopental, of the clinical and histological lesion secondary to cerebral anoxia is effective when this drug is administered before the 15th minute. With 90 mg/kg administered at the 30th or 60th minute the improvement was slight: with 120 mg/kg it was greater if the injection was given at the 60th rather than at the 30th minute. These results, along with the mechanisms which may explain the action of thiopental, are discussed.

Topics: Animals; Brain; Cerebrovascular Circulation; Dose-Response Relationship, Drug; Haplorhini; Hypoxia, Brain; Macaca mulatta; Neurologic Examination; Paralysis; Thiopental; Time Factors

Forty-seven patients undergoing elective/emergency surgery were investigated for the recovery pattern by numerically scoring the state of consciousness, skeletomuscular tone, respiration and blood pressure after the neuromuscular transmission at the level of thenar muscles returned to normalcy. Anaesthesia in them consisted of thiopentone induction and passive ventilation with nitrous oxide and oxygen mixtures (4 1/2:2 1/2 1) with consequent changes in PaCO-2 (22.0 to 90 mm Hg) after using 0.43 to 0.68 mg/kg d-tubocurarine or 2.3 to 3.8 mg/kg gallamine. In this series twelve patients were selected at random and biological assay of cerebrospinal fluid in them for curare/gallamine after 15 min anaesthesia and in the recovery phase was carried out on frog rectus muscle. All the patients recovered satisfactorily and did not present clinical signs of depression of central nervous system, even though all of them showed the presence of curare (ranging from 0.05 to 0.33 mug/ml) and gallamine (from 0.1 to 0.75 mug/ml) in the cerebrospinal fluid. This study therefore indicates that thiopentone, nitrous oxide and relaxant type of anaesthesia does not cause clinical syndrome of post-operative paralysis even when mild to moderate degree of hypocapnia is present and even when such a technique of anaesthesia is administered in poor-risk patients with associated changes in acid-base balance, electrolytes etc. Significant quantities of skeleto-muscular relaxant drug (used during the technique) when found in cerebrospinal fluid after the technique of anaesthesia need not induce post-operative paralysis in man.

Topics: Adult; Anesthesia, General; Blood Pressure; Carbon Dioxide; Consciousness; Female; Gallamine Triethiodide; Humans; Hypercapnia; Male; Muscle Relaxants, Central; Muscle Tonus; Neuromuscular Blocking Agents; Nitrous Oxide; Paralysis; Partial Pressure; Respiration; Respiration, Artificial; Thiopental; Tubocurarine

Topics: Adult; Anesthesia, General; Arm; Female; Halothane; Humans; Laparoscopy; Nitrous Oxide; Pancuronium; Paralysis; Postoperative Complications; Sterilization, Reproductive; Thiopental

Topics: Adult; Cognition; Consciousness; Female; Humans; Intubation, Intratracheal; Male; Middle Aged; Oxygen; Paralysis; Preanesthetic Medication; Succinylcholine; Thiopental

Topics: Anesthesia, General; Drug Synergism; Electric Stimulation; Electrophysiology; Female; Humans; Male; Muscles; Paralysis; Propanidid; Succinylcholine; Thiopental

Topics: Anesthesia; Anesthesia, Intravenous; Blood Pressure; Electrocardiography; Humans; Lung Compliance; Meperidine; Nitrogen; Paralysis; Posture; Pulmonary Diffusing Capacity; Respiration; Respiration, Artificial; Respiratory Function Tests; Scopolamine; Succinylcholine; Thiopental

Topics: Adult; Anesthesia, General; Humans; Lung; Lung Compliance; Meperidine; Paralysis; Posture; Respiration; Respiration, Artificial; Spirometry; Succinylcholine; Thiopental

Topics: Humans; Injections, Intradermal; Injections, Intravenous; Muscular Diseases; Necrosis; Nervous System Diseases; Paralysis; Skin Ulcer; Tendons; Thiopental

Topics: Adolescent; Adult; Anesthesia, Inhalation; Helium; Humans; Lung; Middle Aged; Muscle Contraction; Paralysis; Preanesthetic Medication; Respiration; Respiratory System; Spirometry; Succinylcholine; Thiopental; Ventilators, Mechanical

Topics: Dogs; Electrocardiography; Electroencephalography; Paralysis; Pharmacology; Procaine; Research; Respiration; Seizures; Succinylcholine; Thiopental; Toxicology

Topics: Analgesia; Anesthesia; Anesthesia and Analgesia; Barbiturates; Brachial Plexus; Gallamine Triethiodide; Humans; Muscle Relaxants, Central; Nitrous Oxide; Pain Management; Paralysis; Thiopental

Topics: Anesthesia; Anesthesiology; Barbital; Blood Pressure; Paralysis; Sodium; Spinal Cord; Thiopental