Regional-Anaesthesie最新文献

In regional anesthesia, the localization of peripheral nerves and plexuses is possible by means of mechanical or electrical stimulation. Electrical stimulation for this purpose was first described in 1912 by the surgeon Georg Perthes (1869-1927) of Tübingen, who reported his own experiences. The original description and results of electrostimulation are transposed upon a modern point of view of regional anesthesia.

Direct stimulation of the obturator nerve by the electroresectoscope during transurethral resection of tumors in lateral bladder regions is possible under regional or general anaesthesia without muscle relaxation. The resulting obturator reflex may lead to perforation of the bladder. Two different regional techniques can be used to interrupt the obturator reflex arc: (1) separate block of the obturator nerve; or (2) the "3-in-1 block" (Winnie). In the present study elimination of the obturator reflex was carried out by "3-in-1 block" with diluted solutions of etidocaine in 55 cases. Venous plasma levels of etidocaine were measured in 9 patients after application of etidocaine 0.5% (unilateral 30 ml and bilateral 60 ml). Samples were taken 10, 20, 30, 40, 60, and 120 min after the "3-in-1 block". RESULTS. The "3-in-1 block" with diluted etidocaine produced excellent motor block of the obturator nerve. Clinical side effects did not occur. Plasma peak levels reached 2.2 micrograms/ml; the protein binding rate was 85%-95%. DISCUSSION. Elimination of the obturator reflex is the only specific motor nerve block in anesthesia. Diluted etidocaine solutions seem to be adequate: irrespective the technique used for eliminating the reflex, diluted etidocaine produces a good effect and permits a dosage reduction compared with other local anesthetics. It is possible to block the obturator nerve bilaterally by "3-in-1 block" or unilaterally by "3-in-1 block" in combination with epidural analgesia within the recommended dose limits.

There is a tendency to perform increasingly severe operations on patients of advanced age. Because geriatric patients are of greater risk when under anesthesia during operation, it is necessary to be aware of the possible anesthesia-related and operation-related complications. In a retrospective study the complication rate with regard to patients (age, multimorbidity), operation (e.g. number and duration of procedures) and anesthesia was analyzed. Of particular interest were the kind and degree of certain complications at a particular time. Directly following the induction of anesthesia and the second application of cement the complication rate depended on patient age and multimorbidity, but the intraoperative complication rate was closely related to the operation. Sensory spreading of spinal anesthesia was one of the anesthesiological factors leading to an increase in the complication rate. Cardiovascular complications occurred most frequently following the induction of spinal anesthesia (hypotension: 6.50%, tachycardias: 3.74%, bradycardias: 3.68%). The most serious circulatory complication--shock--however was primarily seen during surgery [1.80% (n = 59)]. Asystoles [0.27% (n = 9)] were only seen intraoperatively and after the second cement application. Pulmonary embolism [0.12% (n = 4)], respiratory arrest [0.09% (n = 3)] and exitus [0.64% (n = 21)] exclusively occurred following the second administration of cement. Geriatric patients are particularly at risk directly after induction of anesthesia and following application of the second cement. Thorough preoperative preparation (with regard to the cardiac and circulatory situation), spinal anesthesia of less than Th 6 and a rapid surgical procedure are necessary to reduce the morbidity and mortality.

There is uncertainty as to which preoperative examinations are necessary before performing regional anesthesia. Therefore an interdisciplinary consensus conference was established to obtain recommendations on some of the open questions related to this topic. Preoperative laboratory examinations are not necessary prior to peripheral nerve blocks near large vessels if these are easy to compress. In patients on anticoagulant therapy direct puncture of the vessel should be avoided. Prior to spinal or epidural anesthesia, no preoperative laboratory examinations are necessary if no anamnestic or clinical evidence of coagulation disorders exists. Otherwise the following examinations are useful: clotting time, prothrombin time, partial thromboplastin time (PTT), and thrombocyte count. Low-dose heparin prophylaxis is no contraindication to spinal or epidural anesthesia. However, in patients at increased risk of bleeding or with low body weight, PTT and thrombocyte count are necessary. Since at present no definite data exist as to the bleeding risk in patients treated with low-molecular-weight heparin prophylaxis, spinal/epidural anesthesia should be performed in controlled studies only under these conditions. This particular precaution seems to be necessary because low-molecular-weight heparin increases levels of plasminogen activators (t-PA) and therefore has fibrinolytic activity. If plasma expanders are administered perioperatively, the highest bleeding risk exists after dextran infusions. There is also an increased bleeding risk if nonsteroidal anti-inflammatory drugs, especially acetylsalicylic acid, are administered repeatedly within 5 days prior to spinal/epidural anesthesia. In these patients preoperative determination of the clotting time appears necessary.(ABSTRACT TRUNCATED AT 250 WORDS)

Regional anesthesia as a method of avoiding stress and preserving the immunological system has found a solid place in the armamentarium of anesthesia departments. Its applicability for anesthesia of higher segments is controversial. In order to test the reliability of this method, at 7 perioperative measuring points we studied respiratory and circulatory parameters of 17 patients undergoing breast surgery. Access to the peridural space was via C6/7 or C7/T1 by catheterization with the hanging-drop method. The respiratory and circulatory parameters were determined by direct measurement of arterial and pulmonary-arterial pressures and by arterial and mixed-venous blood samples. The main criterion was determination of the arterio-venous oxygen difference. It was shown that the cardiovascular and respiratory integrity of the organism remained unaffected. The most marked changes in relation to the starting point were seen at measuring point 5 (40 min after beginning anesthesia): heart rate -22.4% (p less than 0.05), mean arterial pressure -35.1% (p less than 0.05), mean pulmonary-arterial pressure + 18.1% (NS), mixed-venous oxygenation -5.5% (NS), arteriovenous oxygen difference +25.9% (NS) arterial pO2 -4.4% (NS) and pCO2 +7.9% (p less than 0.05). --In the hands of an anesthetist fully acquainted with conduction anesthesia, cervical peridural anesthesia for appropriate indications may be proposed as an alternative anesthesiological method.