[Peak blood levels of mepivacaine following intravenous regional anesthesia using various concentrations]. / Spitzenblutspiegel von Mepivacain nach intravenöser Regionalanaesthesie (I.V.R.A.) bei Verwendung unterschiedlicher Konzentrationen.

In a previous study we assumed, that with I.V.R.A. the peak blood levels after opening the tourniquet would be less when lowering the concentration and simultaneously increasing the volume of the anesthetic solution. For supporting this hypothesis, on 17 patients each the peak blood levels of mepivacaine after I.V.R.A. were determined. For this a 0.25% (gr. A) and 0.50% (gr. B) concentration of solution was given. The same absolute amount (3.75 mg/ml b.w.) of the anesthetic was used and the measured values are compared. The results show a median for the 0.25% solutions of XA = 4,046 ng/ml and for the 0.50% ones of XB = 6,894 ng/ml. The values differ for p less than 0.05 with the onesided mediantest. Our initial assumption is confirmed which consequently contributes to greater safety.

[Prospective comparative study of postspinal headaches in young patients (less than 51 years)]. / Prospektiv vergleichende Studie postspinaler Kopfschmerzen bei jungen Patienten (less than 51 Jahre).

1.009 patients (less than 51 years) were investigated for the frequency of postspinal headaches developing when using different types of needles (22 G and 25 G with Quincke-cut and 22 G Whitacre-needle). It was shown, as expected, that puncture with the smaller needles caused with 6% only about half as many headaches as did taps with the two bigger types of needles, which did not demonstrate any statistical difference between each other. After classifying the complaints as doubtful and definite postspinal headaches the rates of real headaches of the total series was about 5%. The highest frequency of complaints was reported by female patients in the 5th decade. An increase with lesser age was not noticed. Technical difficulties associated with spinal puncture were of almost no importance in influencing the rate of headaches. Definite bloody taps were associated with significantly higher complaint rates. The drugs used (mepivacaine and bupivacaine) did not appear to have any influence. An advantage of the more expensive Whitacre-needle is not seen except in patients with disturbances of coagulation factors.

[Clinical aspects of intravenous regional anaesthesia (I.V.R.A.) (author's transl)]. / Klinische Gesichtspunkte zur intravenösen Regionalanaesthesie (I.V.R.A.).

3 groups of patients undergoing upper extremity surgery were anaesthetized with I.V.R.A. They were prospectively investigated to determine their absolute need of drug and the failure rate. As anaesthetics 0.50%, 0.33% and 0.25% mepivacaine solutions were used. It was found that the reduction in concentration with a combined increase in volume leads to a higher success rate and a simultaneous reduction of the absolute amount of drug. It is recommended to use 1.0-1.5 ml/kg b.w. of the 0.25% solution. If there are scars, adhesions as well as marked swellings at the operative site, it is advised not to use I.V.R.A. because of the greater risk of failure. The low postanaesthetic tendency for swelling and the extension of the operative site to the distal third of the upper arm are additionally stressed. Clinically relevant side effects were not observed.