Regional-Anaesthesie最新文献

In a prospective clinical study the follow-up course of 630 lumbar single-shot and continuous epidural anesthetics in young patients (average age 24.5 years) with 20-25 ml prilocaine 2% (epinephrine concentration 1:200,000) and 0.1 mg fentanyl was examined critically. The patients were interviewed postoperatively about this method of anesthesia. In 89% of cases the patients had been found suitable for surgery without any additional medication; 9% of the patients needed 0.1-0.15 mg fentanyl and 2.5-5 mg midazolam i.v. Only in 10/630 cases was supplementary anesthesia needed. During anesthesia a drop in blood pressure by 30% or more of the original value was recorded in 1.4% of patients; 5 patients had obvious simultaneous bradycardia. Nausea and vomiting were observed in 2.5% of cases; in 6 patients the level of peridural anesthesia was as high as T4-5. Postoperatively, 19% of the patients complained of discomfort in the area of the lumbar vertebral column. It subsided significantly 2 days after surgery; in 5.6% of cases patients had micturition disorder needing treatment. In 93% of cases the patients considered the method of anesthesia quite acceptable; in the same circumstances 96.5% said they would prefer epidural block to general anesthesia. The main reasons for this were the possibility of observing the surgical operation (26.8%) and the likelihood of speedy recovery on the same day (24.3%). Epidural block is preferred to any form of general anesthesia according to the experience we have gained in these young patients without essential concomitant diseases and with exact consideration to the contraindications for all operations distal of segments T9 and T10.

Perioperative antiarrhythmic therapy with lidocaine (bolus dosage 100 mg followed by infusion of 200 mg/h) was performed in 24 patients; 12 of them simultaneously received an intravenous injection of 10 mg midazolam with the bolus of lidocaine (group I: with midazolam; group II: without midazolam). Central venous blood samples were collected over a period of 1 h (1, 3, 5, 10, 20, 30, and 60 min after the bolus) to evaluate unbound and total (protein-bound + unbound) plasma concentrations of lidocaine, thus calculating plasma protein binding. One minute after intravenous administration of lidocaine peak plasma concentrations occurred: in group I 5.38 +/- 1.99 micrograms/ml (mean +/- SD), in group II 5.25 +/- 1.90. Up to 60 min there was only a gradual decrease in plasma concentrations in both groups. There was no significant difference between the two groups (group I: mean free concentration 0.67-0.80 micrograms/ml; mean total concentration 4.84-5.38 micrograms/ml; mean plasma protein binding 83%-86%; group II: 0.69-0.89 micrograms/ml; 4.62-5.25 micrograms/ml; 82%-85%). We draw the conclusion that midazolam administration is safe in patients undergoing antiarrhythmic therapy or regional anesthesia with lidocaine.

In 1988, questionnaires were sent to 1225 departments of anesthesiology to evaluate the practice of postoperative epidural analgesia (EA) in the Federal Republic of Germany. The following problems were investigated. To what extent are anesthesiologists concerned with postoperative pain therapy? Does EA play a major role in this, in particular outside the intensive care setting? Who is allowed to administer epidural injections: anesthesiologists, other physicians or nurses? What kind of monitoring is used? What agents are used for epidural injections and what problems and complications have arisen? In all, 461 (38%) evaluable forms were returned. Most anesthesiologists said they were responsible for postoperative pain control. In 75.3% of the responding departments EA was used as a method of postoperative pain therapy, while in 24.7% the catheter was removed immediately after the operation, in most cases for fear of complications resulting from insufficient monitoring. In clinical practice, however, EA was the only major alternative to routine intermittent injections of opioids as needed. Some departments reported that they restricted postoperative EA to patients in the intensive care unit or in the recovery room because adequate monitoring was not feasible on the ordinary wards. EA was administered in 62.4% on ordinary wards. But in only 25.7% were trained nurses allowed to give epidural injections. Most responding departments (77%) preferred epidural use of opioids during intensive care, in most cases morphine or buprenorphine in combination with low-dose local anesthetics, and 66.7% also favored epidural opioids on ordinary wards.

A 72-year-old female patient was scheduled for abdominal surgery with epidural block in combination with general anesthesia. An 18 G epidural catheter was inserted through an 18 G Tuohy needle between T12 and L1 using the midline approach and the 'loss of resistance' technique. A test dose of 13 ml bupivacaine 0.25% showed no effect and a bolus of 12 ml bupivacaine 0.25% was added 8 min later. Bilateral analgesia between S5 and C4 developed over the following 17 min but was not accompanied by any cardiovascular or respiratory depression. The patient became sleepy and was finally intubated after the administration of thiopentone 175 mg and pancuronium 6 mg. There were no objections to surgery, so the hemicolectomy was continued as planned. Intraoperatively the systolic blood pressure dropped twice, to a minimum of 105 mm Hg, coinciding with eventration of the intestine, but this was reversed immediately on administration of a vasoconstrictor. Extubation of the patient was possible 90 min later on the termination of surgery, when the level of anesthesia had reached T2. A spinal X-ray with radiopaque dye showed a typical intrathecal distribution. Most remarkable in this case is the stability of the cardiovascular function which in our opinion is related to the 0.25% solution. Serious complications of an inadvertent dural puncture can be avoided or alleviated with this concentration if the epidural block is to be combined with general anesthesia.

In a prospective study, 184 patients were studied after orthopedic operations with regard to analgesic requirements, analgesic effectiveness, and appearance of postoperative complications. In four groups, 0.0375, 0.075, 0.1 or 0.15 mg morphine was given in combination with 0.5% hyperbaric bupivacaine for perioperative analgesia. The patients' ages ranged between 13 and 90 years (means = 62.97). One hundred sixteen patients did not need any analgesics in the first 24 h. The effect of the spinal opiate was found to be pleasant, especially by patients who received a total hip prosthesis: in this group the average duration of analgesia was more than 24 h in 77.9% and 14.5 h in 22.1% of patients. The need for additional postoperative analgesia was seen earliest in the patients who received a knee prosthesis of the sledge type (P less than 0.05). The overall consumption of the analgesic piritramid was clearly reduced and amounted to 7.7 mg on the day of operation, 8.4 mg on the 1st day, 6.0 mg on the 2nd day, and 3.6 mg on the 3rd day after surgery. The degree of postoperative analgesia was the same in all four groups (P greater than 0.05). Blood gas analyses, respiratory rate, blood pressure, heart rate, oxygen saturation, and laboratory parameters were also examined. The application of small doses of opiate close to the spinal cord produced a good and long-lasting reduction of pain with few opiate side effects. In the spinal anesthetics with larger doses of morphine, side effects were rare and hardly different from those accompanying spinal anesthesia without morphine addition. There were no serious complications noted during the opiate anesthesia.(ABSTRACT TRUNCATED AT 250 WORDS)

Up to now, mandibular nerve blocks have been carried out without knowing the exact blood concentrations resulting from the use of the local anesthetics. Due to the high vascularity a rapid increase in serum local anesthetic levels is to be expected. Due to analytical problems, the literature provides controversial statements about the pharmacokinetics of articaine which is generally used for this block. The given half-life periods following intramuscular application range from 39 min [8] to 31 h [6]. For this reason, mandibular nerve blocks with 2 ml 4% articaine with 1:200,000 epinephrine were carried out in 10 awake patients and 10 patients during intubation anesthesia. RESULTS. Blood samples from peripheral veins showed an average maximum concentration of 2.1 +/- 1.3 mg/l after 12.5 +/- 2.5 min. After 8 h the value had fallen below the minimum detection limit of 0.05 mg/l. In the present study, a half-life of approximately 20 min was determined for articaine after conduction anesthesia. This local anesthetic holds an exceptional position because as an amide-type local anesthetic it contains an additional ester group that is hydrolytically metabolized in the blood. The concentration of the resulting metabolite reaches a maximum value of 2.6 +/- 1.6 mg/l after 40 to 50 min. CONCLUSIONS. Compared to other amide-type local anesthetics, whose terminal plasma half-life varies between 1 and 3.6 h [5], the value of 20 min found for articaine is very low. This is in part due to its structure, as the ester group is rapidly metabolized by plasma esterases. Because of its rapid breakdown articaine is very suitable for use in oral surgery. The HPLC method represents an uncomplicated analytical technique for the determination of local anesthetics levels in blood and other body fluids.

From the psychological point of view, regional anesthesia is something special because the patient experiences his operation consciously. This means that the anesthetist is required not only to guarantee a safe anesthetic, but also to recognize the special needs of the patients, to enter into them adequately, and thus to support the patient's own strategies for coping with his situation. The question arises as to what extent the anesthetist's behavior meets the patient's psychological requirements. For this reason, the conversation between patient and anesthetist was monitored during 17 operations under regional anesthesia and investigated by means of a quantitative speech analysis. It was shown that the anesthetist clearly predominated in the course of the conversation: particularly during the time when the patient was preparing himself for the operation, it was the anesthetist who actively framed the communication by numerous questions and conversational activities while the patient responsively remains passive. The anesthetist spoke simply and clearly to the patient. Prime consideration was given to explaining the anesthetic procedure and the operation. There were not many attempts by the physician to also deal with the patient's psychic state. On the while, communication was concerned with the quick and easy performance of anesthesia. This was also demonstrated by the fact that conversation between the anesthetist and the patient was nearly absent during the operation.

This randomized study was designed to determine the effects of isovolemic hemodilution and lumbar epidural anesthesia on plasma concentrations of bupivacaine in patients scheduled for endoprosthetic hip surgery. PATIENTS, MATERIALS AND METHODS. The patients were randomly assigned to two groups. In a hemodilution group (n = 15), which included patients undergoing lumbar epidural anesthesia following isovolemic hemodilution (15 ml/kg body weight), withdrawn blood was substituted by colloidal solution (hydroxyethyl starch solution 6%, 450/0.7; ratio of replacement 1:1). Controls were 15 patients who were not subjected to isovolemic hemodilution; epidural anesthesia only was performed. Both groups had identical fluid pretreatment (1000 ml Ringer's solution) before injection of the epidural bupivacaine dose (mean 14 ml, 0.75%); central venous blood samples were drawn at short intervals over 180 min. Both, the total plasma concentrations and the free bupivacaine fractions were determined by HPLC and ultrafiltration. RESULTS. Peak bupivacaine plasma levels (mean 1.30 microgram/ml) were found 10 min after application of the analgesic dose in the control patients. In contrast, in hemodiluted patients mean maximum plasma levels of bupivacaine were measured between the 20th and 30th min, with peak levels of only 0.75 microgram/ml plasma. The unbound bupivacaine levels were not significantly different in both groups over the entire measuring period despite the differing total bupivacaine concentrations. Therefore, protein binding of bupivacaine was about 6% lower in the hemodilution group, especially during the period shortly after injection. DISCUSSION. We conclude that isovolemic hemodilution leads to lower plasma bupivacaine concentrations after epidural anesthesia, probably due to an increased volume of distribution. Protein binding of bupivacaine is reduced by hemodilution; the free, non-protein-bound concentrations of local anesthetic were not associated with any systemic side effects in this study.

A 78-year-old female patient undergoing a hip operation received a catheter for continuous lumbar plexus blockade. The catheter was positioned without complications but its removal had apparently proved to be difficult. The catheter entered the operative site and its tip was coagulated by the coagulation forceps. There were no subsequent complications.