Pharmacokinetics of the local anesthetic ropivacaine after transversus abdominis plane block in healthy volunteers.

PURPOSE: The transversus abdominis plane (TAP) block is a regional anesthetic technique used for pain control following abdominal surgical procedures. While a minimum of systemic side effects is usually expected after local anesthesia, it is unknown to which extent systemic absorption and redistribution to the abdominal wall contributes to the effects of anesthetics. The aim of this study was to determine concentration-time profiles of ropivacaine after the injection of 150 mg of ropivacaine into the lateral abdominal wall in various compartments. METHODS: The microdialysis technique was used to measure ropivacaine in plasma as well as at abdominal wall sites cranial from the injection site (below the 12th rip) and caudal from the injection site (cranial from the iliac crest) and in the skeletal muscle tissue of the contra lateral thigh of eight healthy volunteers. RESULTS: The mean exposure to ropivacaine measured as the area under the concentration-time curve was significantly higher at the two abdominal sites (240.9 ± 409.1  and 86.18 ± 133.50 µg h/mL, respectively) than in plasma (5.1 ± 1.0 µg h/mL) or in peripheral tissue (1.1 ± 1.2 µg h/mL). While the high mean concentrations of ropivacaine measured at the abdominal wall sites support the topical concept of the TAP block, the observed variability was striking. CONCLUSIONS: While the systemic pharmacokinetics was comparable between subjects, the local distribution of ropivacaine was highly variable after TAP block.

Frequency-dependent effects of amitriptyline and maprotiline on conduction in the guinea pig His-Purkinje-system in vivo.

In the Cardiac Arrhythmia Suppression Trial antiarrhythmic drug therapy with slow kinetic sodium channel blockers (class Ic antiarrhythmic drugs) was associated with excess mortality, presumably due to drug induced proarrhythmia. It has been suggested that the degree of rate-dependent conduction slowing produced by agents that have sodium channel blocking properties may be related to the proarrhythmic propensity of these agents. In the present study, rate-dependent conduction slowing by the antidepressants amitriptyline and maprotiline was investigated in anesthetized guinea pigs. After electrical ablation of the sinus node the left atrium was stimulated at cycle lengths between 200 ms and 500 ms. His bundle electrograms were registered by means of an epicardial electrode. Drugs were administered by i.v. infusion of 0.2 mg kg-1 min-1 for 30 min followed by 0.1 mg kg-1 min-1 for up to 30 min. Both drugs produced substantial rate-dependent conduction slowing within the His-Purkinje-system. The relationship between pacing rate and conduction slowing was well fitted by linear regression. The steepness of the regression line was significantly greater for amitriptyline than for maprotiline (slope factors: 9.10 x 10(-4) +/- 7.85 x 10(-5), n = 6, vs. 6.29 x 10(-4) +/- 2.97 x 10(-5), n = 6, P < 0.001), indicating that conduction slowing by amitriptyline exhibits a greater degree of rate-dependence than conduction slowing by maprotiline.(ABSTRACT TRUNCATED AT 250 WORDS)

[Tables for the diagnosis of zygosity in twins relative to hemogenetic polymorphisms]. / Tabellen zur Eiigkeitsdiagnose bei Zwillingen anhand hämogenetischer Polymorphismen.

In order to determine the zygosity relative probabilities in favour of dizygotic twin pairs for 30 hemogenetic systems are given. The basic formulas for the probability calculations are described.

[Ulcerative colitis or amebic colitis--a case report]. / Colitis ulcerosa oder Amöbenkolitis--ein kasuistischer Bericht.

The large intestine reacts relatively monomorphically to different stimuli. From this differential-diagnostic problems may result. The history of a patient is described which could be pursued retrospectively and prospectively over 14 years and during the course of which the correction of the diagnosis ulcerous colitis into chronic relapsing amoebic colitis was necessary. As a conclusion is emphasized that in every symptomatology of colitis primarily bacterial and parasitologic examinations of the faeces should be brought about and it must be also thought of spontaneous amoebic infections in our country.