Best indications for local anaesthetics: bupivacaine.

Bupivacaine is a local anaesthetic of great potency and long duration but has also well known cardio-and CNS toxic side-effects. For many years it was nearby the only local anaesthetic with these characteristics, making it applicable to almost all kind of loco-regional anaesthetic techniques, and still nowadays, for economical reasons it is in many occasions the only alternative available. In this review, departing from analysis of the physical, chemical and pharmacological properties of this molecule and considering also its toxic potencies we wanted to analyze all clinical situations in which it is used. But above all we have reviewed the most recent international literature, which are actually the best indications for this drug, that in the last years with the appearance of first ropivacaine and then levobupivacaine, seemed to have lost its field of elective application. According to these analysis we concluded that this drug, though still remaining a good alternative in many fields of loco-regional anaesthesia (like peripheral blocks), as well as an efficient drug equal to the above mentioned ones in any sector like epidural analgesia in caesarean section, its best indication is subarachnoideal anaesthesia (combined and not) where it is the best available drug in hyperbaric solution without doubts. It might be interesting in the next future the comparison with hyperbaric solutions of levobupivacaine (not yet available).

Forefoot postoperative continuous pain control by nonelectronic device.

The authors present a system against postoperative pain in forefoot operations, which functions by continuous infusion of anesthetic in the malleolar internal space. The system (Single-Day Baxter Infusor) was utilized in 145 patients who had undergone forefoot surgery. The effectiveness of the method was evaluated by means of a numeric scale (0 to 5) reflecting pain level. The method was effective in controlling postoperative pain in 110 cases (score 0 to 1); 25 cases (score 2) reported pain in the dorsal hallux, in the deep peroneal area, whereas in 10 cases (score 4 to 5 on the scale), nonsteroidal anti-inflammatory drugs had to be administered.

[Monitoring of intracranial pressure]. / In tema di monitorizzazione della pressione intracranica (PIC).

A very small fiberoptic catheter initially developed as an intravascular pressure sensor was incorporated into a system to be used as an intracranial pressure (ICP) monitor. 13 patients with intracranial hypertension have been studied with this probe. The clinical experience confirmed the safety, accuracy and reliability of the device. The monitor has functioned very well, and there have been no complications except for two breakages of optic fiber as a result of nursing manoeuvres. This new device can be placed into the ventricular, subdural and epidural space. Camino System appears to offer advantages over other monitors presently in use.

Beta-lipotropin is the major component of the plasma opioid response to surgical stress in humans.

There is growing experimental evidence that beta-endorphin immunoreactivity is raised by surgical stress in patients undergoing general anesthesia. As the assay methods employed to date did not allow to fully discriminate between beta-endorphin and its immediate precursor, beta-lipotropin, we have investigated in the present study plasma levels of these two peptides by separating them by chromatography on plasma extracts prior to radioimmunoassay in eighteen surgical patients under general anesthesia and eight under spinal anesthesia. Beta-lipotropin, but not beta-endorphin, plasma levels were found to be significantly elevated during surgery in the general anesthesia group, while no change was found in either peptide concentration in the spinal one. Cortisol plasma levels also increased significantly 90 minutes after the beginning of surgery, when they were positively correlated to beta-lipotropin ones. Although the sampling time we adopted may have prevented us from detecting an early peak of beta-endorphin during the first 30 minutes of surgery, the major component of the pituitary opioid response to surgical stress appears to be related to beta-lipotropin. This is in agreement with results of experimental work on various kinds of stress in animals and humans and seems to rule out a role for plasma beta-endorphin in post-operative analgesia.

Opioid control of LH secretion in humans: menstrual cycle, menopause and aging reduce effect of naloxone but not of morphine.

A number of studies have been made on the role played by endogenous opioid peptides in the secretion of LH in humans. However no previous studies have compared the effects of the most potent pharmacological agonist and antagonist, morphine and naloxone, in the same subjects. The present study examined the acute effects of injections of morphine and naloxone on plasma LH levels in 30 healthy subjects (18 women and 12 men). Fertile women were subdivided into follicular (n = 6) and luteal (n = 6) phase groups; the remaining 6 were postmenopausal women. The 12 men were sub-divided in two groups of 6 subjects according to age (24-33 years, and over 60 years). There was a two day interval between injection studies in the same subjects. Morphine significantly decreased plasma LH levels in all groups examined (P less than 0.01). On the other hand, naloxone caused a significant increase in plasma LH levels in fertile women during the luteal phase of the cycle, but not during the follicular phase or in postmenopausal subjects, and in young but not in aged men (P less than 0.01). These results indicate that in humans there is a change in the activity of the opioids regulating LH secretion during the menstrual cycle, after menopause and in aged men and that these may be studied by the use of naloxone. The inability of naloxone under certain conditions to increase LH levels reflects the decreased activity of the endogenous system, while morphine, being active in all the subjects, seems to be less discriminative, at least in physiological conditions.