Search PubMed⌕ Search

Biomedical subjects

E Viel

Publications and source records attributed to E Viel.

At least 55 records · Page 3Linked to original sources
PubMed1991

[Non-analgesic effects of opioids].

The aim of the regional administration of opioids is to provide an efficient and prolonged analgesia. Then, opiates can be useful for postoperative analgesia and for the treatment of chronic pain of malignant origin. Analgesia is correlated with several adverse effects of which the most frequent are nausea and itching and the most severe is respiratory depression. Beside the adverse effects, other properties of opiates could be responsible of favourable effects which can be taken in advantage in specific indications. In the postoperative period, epidurally administered opioid can attenuate the neuroendocrine and metabolic responses to surgery and pain. This effect is responsible of a reduction of the resistance to insulin and of a better nutritional balance, especially after major abdominal surgical procedures. Opioids also act by a reduction of the motor functions of the bowel, which perhaps could reduce the incidence of anastomotic breakdowns. Finally, other effects have been reported, as anecdotes, such as the treatment of spasm after bilateral replantation of the ureters, neurologic bladder dysfunctions and enuresis. Spinal administration of opioids has also been used as a treatment of premature ejaculation.

Analgesics, Opioid↗
PubMed1991

[Opioids by the perimedullary route: mechanisms of opioid analgesia].

The identification of multiple opioid receptors and opioid peptides in the 1970 was the starting point of an increasing knowledge on opioid physiology and pharmacology. The mechanisms of action of spinally supraspinal levels. At the spinal level, opioids act by a modulation of specific supraspinal effect is the consequence of the migration of opioids, other in the bloodstream or in the cerebrospinal fluid, towards the encephalon. This action involve complex systems of inhibitory control on spinal structures. Opioids act on specific receptors which have a broad distribution in the central nervous system. the classification of opioid receptors is based on the activity of specific ligands: mu (morphine), kappa (ketocyclazocine), sigma (SKF 10047), delta (leu-enkephalin) and epsilon (beta-endorphin). Evidence for the existence of different isoreceptors for each type has been given by experimental studies. At the receptor level, opioid agonists act, hypothetically via the system of adenylcylase, more certainly via a modulation of membrane tonic channels. Thus, opioids modify sodium, calcium and potassium currents, and modify the successives phases of the membrane action potential. The result is an hyperpolarization which is responsible of an inhibition of the release of various neurotransmitters such as P substance.

Analgesia, Epidural↗
PubMed1991

[The use of opioids by the regional route in obstetrics].

Epidural and spinal administration of opioids in obstetrics can be used during labour and for cesarean section. Although these routes of administration are of limited use when opiates are employed as sole agents, the association with local anesthetics may improve the characteristics of analgesia. The administration of a local anesthetic-opiate mixture allows a reduction of the total amount of local anesthetics, thus reducing the incidence of maternal hypotension and the percentage of instrumental extraction. In the particular setting of cesarean section, opioids could shorten the onset and improve the quality of the duration of analgesia. Opioids may also be used for postoperative analgesia after cesarean section. Since they could be responsible for an opioid-related respiratory depression in the mother and the neonate, a strict supervision is absolutely necessary following this particular mode of administration of opiates. If human and technical means of supervision failed to bring into operation, it would be better not to use opioids by the spinal route in such a context.

Analgesia, Epidural↗
PubMed1990

[Use of morphinomimetics in regional anesthesia].

Pain relief is one of medicine's most important challenges and the first aim of anaesthesia. The most common technique of postoperative analgesia remains intramuscular or subcutaneous opiates. There has been a better understanding of the mechanisms of action of opiates over the last decade, and new techniques and methods of administration have been developed especially their regional application. In 1979, two reports acted as catalysts to promote further studies. Wang et al. reported on the efficacy of intrathecal morphine to relieve unbearable malignant pain in 8 patients whereas Behar et al reported on the efficacy of morphine by epidural route. More recently, several studies pointed out the usefulness of the peripheral perineural route for opiates. However, this remains controversial, as some discrepancies persist in the results. The classification of opiate receptors and their relationship to opiate analgesia, as well as the mechanisms of action of regionally administered opiates are analyzed. The dual pre- and postsynaptic actions of spinal opiates are then considered. The parts played by the different neurotransmitters and pathways are set out. The evidence for opiate receptors at peripheral nerve sites and the different hypotheses suggested to explain the effect of opiates given by the perineural route are discussed. The pharmacokinetics and pharmacodynamics of opiates given by the subarachnoid and epidural routes are considered, in particular with respect to the comparative pharmacology of the commonly used opiates. The adverse effects of spinal opiates are reviewed, with their potential risks, and their clinical and therapeutic implications. Opiates and local anaesthetics given by the spinal route are compared. The clinical applications of intrathecal and epidural opiates are discussed, especially in the fields of postoperative analgesia, treatment of chest trauma, and cancer pain. Lastly, the few controlled studies concerning the use of opiates in peripheral nerve blocks, especially brachial plexus blocks, and the prospects of this new technique of giving opiates regionally are discussed.

Analgesics, Opioid↗
PubMed1990

[Treatment of acute hepatic encephalopathy with flumazenil].

In animal studies as well as in a few cases in humans, the benzodiazepine antagonist flumazenil has been shown to reverse hepatic encephalopathy. The authors treated 3 patients with acute hepatic encephalopathy stage III or IV complicating cirrhosis. Two patients had an immediate recovery, maintained with a continuous infusion of flumazenil. In the third patient the clinical status dit not improve but the hepatic encephalopathy coexisted with major abnormalities in blood gases and electrolytes abnormalities, which could participate to the neurologic failure.

Acute Disease↗
PubMed1989

Is epidural anaesthesia using bupivacaine safe in patients with atrio-ventricular conduction defects?

Bupivacaine is known to interact with the conductive system of the heart, also when used in epidural anaesthesia. Ten patients, undergoing bupivacaine epidural anaesthesia for lower limb or pelvic surgery, who presented a history of cardiac conduction disturbances, were studied. The ECG was continuously monitored and a right ventricular bipolar electrode was used to monitor the following parameters: heart rate, QRS duration, QT, Atria-His and His-Ventricle intervals. No significant change was noticed, even in patients with a high grade conduction defect. The mean plasma level of bupivacaine was 0.33 +/- 0.23 micrograms/ml. Based on this experience, it seems that lumbar epidural anaesthesia with bupivacaine can be safely used in patients with asymptomatic AV conduction abnormalities.

Anesthesia, Epidural↗
PubMed1983

Hepatic resection with an Nd:YAG laser in pig.

Eleven hepatic resections were performed by means of a divergent Nd:YAG laser. The beam was transmitted through a fiberoptic delivery system without any handpiece. The shortest resection time and most limited ischemic damage (4 mm) were obtained with 80-W power shoots and a low divergent beam (4 degrees 2 for full angle). The hemostatic effects of the Nd:YAG controlled bleeding from veins of up to 4.5 mm in diameter, and parenchymatic oozing from the cut edge minimized blood loss. Histological examination revealed the importance of cellular deterioration in the ischemic layer, while electron microscopy showed selective destruction of cell organelles and protein denaturation. Marked elevation of hepatic serum enzymes suggests a high degree of cellular damage. Postoperative examinations confirmed an uncomplicated healing process. Finally, the use of a flexible fiberoptic enables easy surgical manipulation.

Animals↗
PubMedDate not supplied

[Technics of locoregional anesthesia of the lower limb].

Regional anesthesia represents a selective method for surgery of the lower limbs because of its simplicity and its handiness. The various techniques of regional anesthesia are analysed with their risks and benefits. Epidural and spinal anesthesia represent safe and simple methods. Moreover, epidural anesthesia enables postoperative analgesia by means of a continuous infusion of local anesthetics or the injection of narcotics. Nervous blocks of the lower limbs represents also safe techniques especially for elderly patients and for day-case surgery. Intravenous regional anesthesia does not represent an usefull technique because of the possible toxicity due to a great volume of local anesthetic drugs.

Anesthesia, Conduction↗
PubMedDate not supplied

[Dopplerography of the venous return of the foot in the healthy subject. Preliminary to a study of ambulation].

The direction of venous return was monitored continuously by the Doppler method at 4 MHz, in order to study the effects of posture and certain kinesitherapeutic maneuvers on venous return in the foot of young, healthy and trained adults (kinesitherapy monitors, yoga assistants). It was noted that: the acceleration of venous return in the foot was expiratory in the recumbent position and inspiratory in the standing position; dorsiflexion (leg on foot or toes on heel) caused a more pronounced spurt phenomenon than plantar flexion; massage repeated at high frequency is less beneficial for venous return than slower massage, which allows better adaptation of venous compliance.

Blood Flow Velocity↗
PubMedDate not supplied

[Application of the Doppler examination to the study of changes in the venous circulation of muscles during exercise].

The authors use Doppler examination to study the functional hyperaemia of healthy muscle during muscle contraction. In the leg, isometric contraction of the gastrocnemii produces: 1) a flush effect, rapid but transient (1 to 2 sec.); 2) next a speed intermediate between that at peak and that at rest; 3) finally, a post-contractile hyperaemia. In the case of isotonic contractions, the same type of tracing is oberved more clearly for dorsal flexion of the foot (dorsiflexion) than for plantar flexion (extesion), and this occurs whether the mode of movement is active or passive. In the normal untrained subject, fatigue due to repetition of movement occurs very quickly, whatever the conditions, and results in a diminution of the venous flush. But in the trained subject, this effect does not appear, or not till much later.

Adolescent↗