[Spinal anesthesia with bupivacaine. Comparative study of 2 hyperbaric and isobaric solutions]. / Rachianesthésie à la bupivacaïne. Etude comparative de deux solutions hyperbare et isobare.

This study compared two isobaric and hyperbaric solutions of 0.4% bupivacaine used for carrying out spinal anaesthesia in 264 patients more than 70 years old undergoing comparable surgical procedures. With the hyperbaric solution, the mean time of onset of analgesia was shorter: 8.4 +/- 4 min (11.5 +/- 5.1 min with the isobaric solution), the level of analgesia higher by two dermatomes and the mean duration of analgesia longer: 147.3 +/- 24.8 min (121.1 +/- 24.8 min with the isobaric solution). Blood pressure fell more often with the hyperbaric solution. The motor block, assessed by the inability to move the legs and abdominal wall paralysis, was more complete with the hyperbaric solution. Lastly, there were less failures: 3.4% with hyperbaric solution and 12.1% with isobaric solution.

[Unsynchronized ventilation of each lung with a selective and expiratory pressure in treatment of unilateral swallowing pneumopathy (author's transl)]. / Ventilation à poumons séparés avec pression positive résiduelle sélective. Utilisation au cours du traitement d'une pneumopathie de déglutition unilatérale.

A case of unilateral lung disease, treated by independent unsynchronized ventilation of each lung, with a selective end expiratory pressure is reported. The better effects of this method seem to be the improvement of respiratory mechanics and gas exchange and the decrease of the intrapulmonary shunt.

Cerebral blood flow and metabolism during etomidate anaesthesia in man.

The effects of etomidate on regional cerebral blood flow (rc.b.f.) and cerebral metabolic rate for oxygen (CMRo2) were studied in seven patients undergoing diagnostic carotid angiography. Following determination of baseline rc.b.f. while awake, the patients were anaesthetized with a single dose of etomidate 15 mg. Thereafter, an infusion of etomidate (2 or 3 mg min-1) was administered. Etomidate decreased both rc.b.f.10 (mean decrease 34%) and CMRo2 (mean decrease 45%). It was concluded that etomidate is a potent cerebral metabolic depressant. Furthermore, the cerebrovascular reactivity to carbon dioxide was maintained under etomidate anaesthesia.

Effects of a diazepam-fentanyl mixture on cerebral blood flow and oxygen consumption in man.

The effects of a mixture of diazepam and fentanyl on cerebral blood flow (c.b.f.) and cerebral metabolism of oxygen (CMRo2) were studied in eight normal subjects and 13 patients with organic brain disease. The coupling of flow and metabolism and the carbon dioxide responsiveness of the c.b.f. were studied also. In the normal subjects the injection of the mixture resulted in a significant decrease in c.b.f. (34%), and a similar decrease in CMRo2 (34.5%). The vasoreactivity of the brain to carbon dioxide was maintained. C.b.f. decreased in all patients with intracranial pathology.

[Pneumoencephalotomography under diaz-analgesia and narco-analgesia]. / Encéphalotomographie gazeuse sous diazanalgésie et narco-analgésie.

The authors reported 92 observations of anesthesia for gaseous encephalotomography interest the adult. The contrast produce is air. 49 under diazanalgesia and myoresolution. Diazepam, +Fentanyl, pancuronium bromide N2O to 60 p. 100. 25 under diazanalgesia and myoresolution. Diazepam, +Fentanyl, succinylcholine, N2O to 60 p. 100. 18 under narco-analgesia and myoresolution. +Fentyl, pancuronium bromide N2O to 60 p. 100. The conditions of the study are described in the first part. The results and their analysis permit the appreciation of: - the patient confort, the quality of the examination; -the respect of the hemodynamics for this examination, reputed to be "difficult"; -the immediatly noticeable diminution of side effects; -the absence of side effects; -the justification and interesting of the control ventilation; -the quality of waking up. In the conclusion the authors underline the interest of their different techniques and the possibility of using them in operations in sitting position in neurosurgery, and all important chirurgical intervention.

Cerebral blood flow in migraine and cluster headache. Compartmental analysis and reactivity to anaesthetic depression.

CBF was studied in 15 cases of vascular headache by the 135Xe intra-arterial injection method. The mean CBF was found to be increased during the headache phase of the migraine attacks in half the cases, mainly due to an increase in the rapid component (CBFg). After the attack there could be an increase or a decrease of the slow component (CBFw). Reactivity to anaesthetic depression was studied in 8 migraine cases and on the whole it was found not to be much altered in most cases. Finally, no modifications of CBF were found in any of 3 cases of cluster headache who were studied during attacks of severe pain.

Cerebral ischemia with CT.

One hundred fifty-eight patients with cerebral ischemia, and divided into four clinical groups were studied with CT. The results were correlated with those of angiography, scintigraphy and regional cerebral blood flow measurement. CT evolution was closely correlated with clinical and anatomical evolution. Changes in cerebral parenchyma density, in relation to the ischemic lesion, are the result of two phenomena: first, edema showing a fairly stable peak of intensity in the 2nd week and disappearing totally before the 20th day; and second, necrosis, variable in extent from patient to patient at the onset with subsequent evolution towards cavitation and thus a density similar to that of cerebro-spinal fluid.

[Effects of high doses of morphinomimetics (fentanyl and fentathienyl) on the cerebral circulation in normal subjects]. / Effets des fortes doses de morphinomimétiques (fentanyl et fentathiényl) sur la circulation cérébrale du sujet normal.

The effects of large doses of morphinomimetics on the cerebral circulation were studied in 12 normal subjects (fentanyl 16 microgram/kg in 6 patients and fentathienyl 1.9 microgram/kg in 6 others). Mean hemispheric flow (corrected to a pCO2 of 40) changed from 50.8 +/- 4.4 ml/100 g/min in the conscious state to 50.3 +/- 25.1 under the influence of fentanyl, and flow in the grey matter from 78.8 +/- 10 to 84.3 +/- 65 ml/100 g/min. Mean flow changed from 49 +/- 3.1 ml/100 g/min in the conscious state to 55.5 +/- 10 under the influence of fentathienyl, flow in the grey matter increasing from 75 +/- 9 to 81.8 +/- 14.4. Whilst there was no variation in mean flow rates under the influence of morphinomimetics, individual behaviour was very variable, in particular in the case of fentanyl, the changes produced by fentathienyl being much more homogeneous. There was no obvious modification in the distribution of regional flow by these morphinomimetics. Individual variations in flow correlated perfectly with individual variations in cerebral oxygen consumption. Vascular reactivity to CO2 was increased b morphinomimetics. In one subject, fentanyl produced a very marked increase in cerebral blood flow (+ 104 p. 100) for which no explanation could be found.

[Cerebral blood flow and metabolism under "diazanalgesia" (author's transl)]. / Débit et métabolisme cérébral sous diazanalgésie.

"Diazanalgesia" employs the combination diazepam + fentanyl. Its effects were studied on regional cerebral blood flow and oxygen metabolism in 8 normal subjects, who were examined angiographically. During diazanalgesia, cortical blood flow falls by 56 p. 100. The mean hemispheric flow calculated over 10 min falls by 34 p. 100. Cerebral O2 consumption (VcO2) falls by 34 p. 100. However, large individual variations are found which suggests that the fall in blood flow is not due solely to the decrease in O2 metabolism. The decreases in flow are not proportional to the amount fentanyl, and there is no direct relation between falls in VcO2 and amount of fentanyl. Cerebral vaso-reactivity to CO2 persists but is reduced under diazanalgesia compared with the waking state.

[Changes in regional blood flow of the brain during althesin anaesthesia (author's transl)]. / Modification du débit sanguin régional du cerveau au cours de l'anesthésie par l'alfatésine.

The effect of Althesin on local blood flow in the brain was studied using intra-carotid Xenon 133 in 18 subjects: 6 apparently normal, 6 with diffuse cerebro-vascular pathology, and 6 cases of ischaemic cerebral accidents identified by scintigraphy, tomodensitometry and angiography. Blood flow decreased under Althesin in the first 2 groups, although to a lesser extent in the second group, with a concomitant decrease in oxygen metabolism. In the third group a "paradoxical" increase in blood flow was observed in infarcts, and a decrease proportional to the rest of the brain in limited ischaemia which had subsequently regressed. The "Althesin test" proposed by Rasmussen (1975) thus reveals the existence of a disconnection between blood flow and metabolism within cerebral infarcts, and provides a possible means of differentiating the latter from reversible ischaemias.