Analysis of spontaneous activity patterns of human thalamic ventrolateral neurons and their modifications due to functional brain changes.

In the human thalamic ventralis lateralis nucleus the spontaneous activity of 235 single units during 38 stereotactic operations in locally anaesthetized parkinsonian patients was analysed. Two basic cell types (A and B) were shown to exist in this nucleus: (i) with unitary irregular (2-40/s) discharges characterized by a tendency to spike grouping in the range of 4-6 Hz and 10-30 Hz (A-type, 74%), (ii) with bursting discharges firing in short trains (5-30 ms) characterized by an unstable rhythmic 3-6 Hz pattern similar to a low-threshold Ca2+ intrinsic burst structure of discharges (B-type, 26%). The functional brain changes after a motor tests performance were accompanied by the appearance of two different transient modifications of activity of A-cells pattern into rhythmic burst discharges: (i) in the range of 3-6 Hz, similar to the bursts found for B-cells and recorded mainly in the anterior ventrolateral region in rigid patients, (ii) in the range of 5 +/- 1 Hz, characterized by other interspike interval and recorded in the posterior ventrolateral region in patients with tremor. Modifications during short-term anaesthesia resulted in 10-15 Hz burst discharges that were associated with gradual disappearance of A-cells activity. In contrast to what happens for A-cells, the activity of bursting B-units was characterized by an invariant intrinsic structure of discharges irrespective of the functional brain changes or the forms of parkinsonian pathology. The nature of A- and B-units as well as the mechanisms of transient modifications of their spontaneous activity patterns due to the functional brain changes are discussed.

[Anesthesia with propanidid in a liposomal preparation. An experimental study in swine]. / Anästhesie mit Propanidid in liposomaler Zubereitung. Eine experimentelle Studie am Schwein.

BACKGROUND: Propanidid was widely used as a short-acting i.v. anaesthetic until it was withdrawn due to severe haemodynamic side effects. It was presumed that anaphylactoid reactions with massive histamine release were caused by the solvent cremophor rather than by propanidid itself. A new liposomal preparation of propanidid was examined in this animal study and compared with propanidid in cremophor solution and with propofol. METHODS: Eighteen pigs were randomly assigned to one of the following groups: Group 1 (n = 6): Propanidid in liposomal preparation (PropaLip; Braun Melsungen, Germany). Anaesthesia was induced with 60 mg/kg, followed by continuous infusion of 400 mg/kg.h. Group 2 (n = 6): Propanidid in cremophor solution (PropaCrem; Sombrevin, Gedeon Richter, Budapest) 15 mg/kg, 100 mg/kg.h. Group 3 (n = 6): Propofol (Disoprivan, Zeneca, Plankstadt, Germany) 5 mg/kg, 20 mg/kg.h. After induction and tracheal intubation, the animals were ventilated with 50% oxygen in air. Basic monitoring included noninvasive blood pressure measurements, electrocardiographic monitoring, and capnography. In a short surgical procedure, arterial and pulmonary artery catheters were placed via the right carotid artery and right internal jugular vein, respectively. As soon as the animals responded to a pain stimulus a second anaesthetic induction was performed, followed by a 60-min continuous infusion of the agent studied with invasive haemodynamic monitoring including arterial and pulmonary arterial pressures and cardiac output. Blood samples were taken for the measurement of serum levels of adrenaline, noradrenaline, cortisol, aldosterone, adrenocorticotropic hormone, and histamine. RESULTS: Intubation conditions and quality of anaesthesia were best in propofol animals, followed by PropaCrem animals. In spite of the large dose of 410 mg/kg.h, resulting in a volume load of as much as 16.4 ml/kg.h, the PropaLip animals showed evidence of poor anaesthetic quality. In group 1 we recorded the highest increases in heart rate (91 vs. 115/min), cardiac output (5.4 vs. 7.7 l/min), plasma catecholamine levels, and histamine concentrations (124-268 ng/ml). CONCLUSIONS: In our animal study, propanidid in liposomal preparation failed to show promise as a new anaesthetic agent. Our results are discussed in view of a drug targeting the cells of the reticuloendothelial system, especially the liver, where liposomes are eliminated from the blood. This may result in the transport of propanidid to one of its major places of inactivation.

[Transcranial Doppler sonographic study of the effect of electroconvulsive therapy on the circulation in the median cerebral artery]. / Az electroconvulsiv kezelés transcranialis Doppler sonographiás módszerrel megfigyelt hatása az arteria cerebri media keringésére.

The authors monitored the circulation of middle cerebral artery in subdominant hemisphere using the transcranial Doppler sonographic method during electroconvulsive treatment. They intravenously administered the patient 500 mg propanididum to put him/her to sleep and 150 mg of suxamethonium for muscle relaxation. The phasis of narcosis and awakening were continuously recorded under the treatment. After the administration of propanididum a sudden brief rise in flow velocity was measured with transient bradycardia followed by tachycardia. After the muscle relaxation the peak flow velocity diminished long lasting and the mean flow velocity fell from 60 cm per second to 30 cm per second average. At the beginning of the electroconvulsive treatment the velocity suddenly rose. The flow velocity increased significantly during the clonic phase of convulsive jerks with the pulsatility indices falling rapidly. Very low pulsatility indices lasted for long period of time during and following clonic convulsions.

[Intravenous anesthesia for cesarean section. Comparison of propanidid and methohexital]. / Anesthésie intraveineuse pour césarienne. Comparaison du propanidide et du métohexital.

Propanidid and methohexital were compared retrospectively to assess the possible neonatal depression following general anesthesia for caesarean section: both have rapid onset and short duration of action and their transplacental passages are similar. Anesthesia was induced with equivalent doses of the two agents in 90 women (45 in each group). For each anesthetic agent, three subgroups were defined according to the indications, depending on emergency criteria and fetal state. There was no significant statistical difference (Student test) regarding clinical and biochemical criteria except for the fetal arterial pH which was more acidic in the propanidid group. In both groups, Apgar scores, arterial and venous pH were significantly more altered when caesarean section was performed for acute fetal depression.

[Comparison of propofol and propanidid administered at a constant rate]. / Comparaison du propofol au propanidide administrés à débit constant.

So as to compare the anaesthesia obtained using propofol with that obtained using propanidid, 40 ASA I patients, aged between 18 and 50 years, who were to undergo elective orthopaedic or plastic surgery lasting more than 60 min, were randomly divided into two equal groups, one receiving propofol (PF) and the other propanidid (PD). All the patients received 0.5 mg atropine, 100 mg pethidine and 7.5 mg droperidol (10 mg if weight greater than 60 kg) intramuscularly 45 min before induction. Patients in group PF were then given 2 mg.kg-1 propofol over 1 min and 0.9 microgram.kg-1 fentanyl over 3 min, followed by a constant rate infusion of 5 mg.kg-1.h-1 propofol and 3 micrograms.kg-1.h-1 fentanyl. For PD patients, the doses of fentanyl were identical; they were given 10.6 mg.kg-1 propanidid over 3 min for induction, and 37 mg.kg-1.h-1 for maintenance. All the patients were intubated and ventilated mechanically. The usual anaesthetic parameters were monitored at induction, during surgery, and during recovery. Consciousness was lost more quickly with propofol (p less than 0.05), but the corneal reflex returned more rapidly in group PD (p less than 0.02). The time required for a full return to normal consciousness was identical in both groups. The fall, during induction, and the increase, during recovery, of Pasys were greater in group PD (p less than 0.05 and less than 0.001 respectively). Padia and heart rate were lower in group PF after the 30th min (p less than 0.05 and less than 0.01 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

[Intravenous monoanesthesia and antianesthetics in emergency surgery]. / Vnutrivennyi mononarkoz i antinarkotiki v ékstrennoi khirurgii.

Profiles of using the intravenous mononarcosis (sodium hydroxybutyrate, viadryl , ketamin , sombrevin, seduxen) in urgent surgery and traumatology are analyzed. Choice of certain narcotics is motivated for patients with blood loss and shock, intoxication, insufficiency of kidneys, adrenals and liver, cardio-vascular and respiratory disorders. The problem of antinarcotics is considered with reference to the efficiency of specific (bemegride, gutimine , amtizol , cytochrome "C") and nonspecific ( osmodiuretics , infusion media containing thawing water) antinarcotics . A preliminary assessment of the efficiency of different drugs of antinarcotic action is given.

[Potentiation of ultra-short term anesthesia (Epontol) with diazepine and psychotropic drugs]. / Potenziamento della narcosi ultrabreve (Epontol) con diazepine o psicofarmaci.

Statistics showing the good results obtained with the prolonged use of propanidid in association with Diazepine and a special type of psychodrug (Trazodone) in a large number of short and long anaesthesias suggest some remarks about the possibility of using this "ultrabrief" narcotic in a wide variety of operations that might otherwise require other anaesthetic behaviour.