Regional-Anaesthesie
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Regional-Anaesthesie · Aug 1990
[Maternal and neonatal plasma concentrations of bupivacaine during peridural anesthesia for cesarean section].
Many anesthesiologists prefer epidural anesthesia for cesarean section because of the potential risks of general anesthesia such as Mendelson's syndrome. For this indication, the local anesthetic of first choice is the long-acting substance bupivacaine. The aim of the following study was to determine maternal and neonatal plasma concentrations of bupivacaine 0.5% following epidural anesthesia for cesarean section in order to give critical statements about the systemic toxicity of the local anesthetic. ⋯ Using bupivacaine 0.5% for epidural anesthesia for cesarean section, we found maternal and neonatal plasma concentrations of the local anesthetic far below the accepted threshold level for producing systemic toxic reactions. In contrast to others, we obtained good analgesia and sufficient motor blockade accompanied by low plasma levels. In our opinion, there is no need to use 0.75% bupivacaine, especially since peak plasma concentrations of more than 2 micrograms/ml occur shortly after its epidural administration.
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Regional-Anaesthesie · Jul 1990
Comparative Study[Axillary blockade of the brachial plexus using 60 ml prilocaine 0.5% vs. 40 ml prilocaine 1%. A clinical study of 144 patients carried out by the determination of the prilocaine concentration in the central venous blood and by the measurement of the subfascial pressure in the plexus following the injection].
We estimated in this study the efficacy of axillary plexus blockade with 60 ml prilocaine 0.5% (300 mg). Following electrostimulation of the median, radial or ulnar nerve (depending on the area of the hand to be operated on), we injected prilocaine in two groups of patients (large volume group, 60 ml prilocaine 0.5% in 20 s; n = 114 patients; normal volume group, 40 ml prilocaine 1% in 20 s; n = 30 patients). Anesthesia of the median and ulnar nerves was virtually complete in all patients, but anesthesia of the radial and musculocutaneous nerves was complete in only 67% (radial) and 75% (musculocutaneous) in the group with normal injection volume. ⋯ Estimation of the prilocaine concentration in the central venous blood 120 min after injection did not reveal different plasma concentrations in the two groups. The plasma concentrations were far below toxic levels. Only the time of plasma peak was earlier in the group with the larger volume, which was attributed to the larger area of diffusion of the vascular system in the plexus space.(ABSTRACT TRUNCATED AT 250 WORDS)
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Regional-Anaesthesie · Jul 1990
[An accidental motor blockade of the femoral nerve following a blockade of the lateral femoral cutaneous nerve].
One hundred fifty successful blockades of the lateral cutaneous nerve of the thigh according to the technique of Eriksson with 7-10 ml prilocaine 1% or bupivacaine 0.25% for meralgia paresthetica resulted unexpectedly in 4 cases of complete and 5 cases of partial motor block of the femoral nerve. The fully reversible paralysis or paresis of parts of the lower limb following blockade of the lateral cutaneous nerve of the thigh is explained as a partial 3-in-1 block.
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Regional-Anaesthesie · Jul 1990
[Intravenous regional anesthesia of the foot using prilocaine. Clinical aspects, pharmacokinetic and pharmacodynamic studies].
Intravenous regional anesthesia (IVRA) of the foot is a rarely used but alternative method to other regional techniques and general anesthesia, especially when operating on the distal portion of the lower limb. The present report describes our method and experience with this type of anesthesia in approximately 500 patients, including pharmacokinetic and -dynamic aspects. MATERIALS AND METHODS. ⋯ In order to avoid systemic toxic reactions, the use of prilocaine is recommended. Prolocaine plasma concentrations and methemoglobin formation were both far below toxic levels. Failure of IVRA was probably caused by premature outflow of the local anesthetic solution, as shown by the course of prilocaine plasma concentrations and methemoglobinemia.
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Regional-Anaesthesie · May 1990
Comparative Study Clinical Trial Controlled Clinical Trial[Ropivacaine in epidural anesthesia. Dose-response relationship and a comparison with bupivacaine].
Ropivacaine is a new long-acting local anesthetic with a pharmacodynamic profile resembling that of bupivacaine; in addition, ropivacaine has been shown to be less cardiotoxic than bupivacaine in dogs and pigs. To test the dose-response relationship of ropivacaine 0.75% (epinephrine 1:200,000) given epidurally, 47 patients were divided into three groups; the first group received 15 ml (n = 16), the second 20 ml (n = 15), and the third group, 25 ml (n = 16) ropivacaine. Further, to compare bupivacaine 0.75%, bupivacaine 0.5% and ropivacaine 0.75% for epidural anesthesia, 15 ml bupivacaine 0.75% (n = 15) or bupivacaine 0.5% (n = 15) or ropivacaine 0.75% (n = 16) was given epidurally, all with epinephrine added to the solution (1:200,000). ⋯ A total of 77 patients with ASA I or II were enrolled in a non-randomized open-label study. All patients were scheduled for varicose vein stripping. Male and female patients aged 18-70 and weighing 50-100 kg were included in the study. Patients were all placed in a sitting position and the epidural space was identified by the "loss of resistance" technique using a midline approach at the L 3/4 interspace; a test dose of 3 ml local anesthetic was then given, followed by injection of the remainder of the local anesthetic at the rate of 10 ml/min 1 min later. Following injection patients were immediately positioned supine. Upward and downward spread of analgesia were determined bilaterally by the pin-prick method, motor blockade was assessed by use of the Bromage scale following each determination of analgesia. Heart rate and blood pressure were obtained immediately before blockade and every 5 min until 3 h after the injection. RESULTS. The different volumes of ropivacaine 0.75% (15, 20, and 25 ml) brought about adequate analgesia in the sacral and lumbar regions in all patients. In the thoracic region T 6, T 5 and T 4 were reached. The time of onset of analgesia (segment L-1 in all three groups) was 6.4 +/- 2.9 min, 7.7 +/- 2.3 min, and 5.6 +/- 2.9 min for the 15-, 20- and 25-ml groups, respectively. The highest thoracic dermatome was reached after 20 +/- 6 min, 26 +/- 11 min, and 18 +/- 5 min. The duration of sensory anesthesia at the T 10 dermatomal level was 250 +/- 68, 249 +/- 77, and 278 +/- 51 min. Two-segment regression time was 160 +/- 67 min for bupivacaine 0.75%, 140 +/- 60 min for bupivacaine 0.5%, and 124 +/- 29 min for ropivacaine 0.75%. The total duration of sensory block was 303 +/- 58, 290 +/- 70, and 343 +/- 55 min for 15-, 20- and 25-ml groups, respectively. The degree of motor block achieved was 1.6, 1.8, and 2.0 (Bromage), respectively. Sensory anesthesia was considered adequate for surgery in all patients, and no signs of systemic toxicity were observed in any of the patients. The comparison of bupivacaine 0.75%, bupivacaine 0.5% and ropivacaine 0.75% revealed the same latency period of analgesia for bupivacaine 0.75% and ropivacaine 0.75%. This was shorter than for bupivacaine 0.5% (bupivacaine 0.75%: 6.4 +/- 2.1, bupivacaine 0.5%: 7.8 +/- 4...