N G Levein

Örebro University Hospital, Örebro, Örebro, Sweden

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Publications (4)13.1 Total impact

  • N G Levein, S E Thörn, M Wattwil
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    ABSTRACT: The effects of clonidine and dopamine, both alone and together, on gastric tone were studied using an electronic barostat. This enabled volume changes to be measured in an intragastric bag with a constant preset pressure. Nine healthy male volunteers were each studied on two occasions in a randomized order. During each study period, a continuous infusion of dopamine was given, starting with a dose of 2.5 microg kg(-1) min(-1), and then increasing at 15-min intervals to 5.0 and 7.5 microg kg(-1) min(-1). Clonidine 150 microg intravenously was given on one occasion during the infusion of dopamine (7.5 microgkg(-1) min(-1)) and on the other occasion 15 min before the dopamine infusion started. During dopamine infusion, the intragastric bag volume increased (gastric tone therefore decreasing) in a dose-related manner (total increase 290 +/- 114 mL). Clonidine given either during or before dopamine infusion did not influence the bag volume. When the dopamine infusion started 15 min after clonidine, the bag volume did not change until the infusion of dopamine reached 7.5 microg kg(-1) min(-1) (total increase 205 +/- 156 mL). Dopamine reduced gastric tone in a dose-related manner, and clonidine did not influence gastric tone per se. If clonidine is given before dopamine, the effects of dopamine are reduced.
    European Journal of Anaesthesiology 03/2002; 19(2):99-104. · 2.79 Impact Factor
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    ABSTRACT: Dopamine may have effects on gastrointestinal motility. The aim of this study was, therefore, to determine whether dopamine reduces gastric tone and whether the effects of dopamine can be blocked by a dopamine antagonist. Eight healthy male volunteers were studied on two occasions in a randomized order. A continuous infusion of incremental doses of dopamine (2.5, 5.0, 7.5 microg kg(-1) min(-1)) was given on both occasions. Ten milligrams of the dopamine-antagonist metoclopramid was given before the dopamine infusion on one occasion and during the dopamine infusion (7.5 microg kg(-1) min(-1)) on the other occasion. The gastric tone was measured by an electronic barostat, an instrument with an electronic control system that maintains a constant preset pressure within an air-filled, flaccid intragastric bag by means of momentary changes in the intragastric volume of air. Volume and pressure in the gastric bag were continuously recorded by the electronic barostat and sampled in a computer. Dopamine induced a dose-related increase in the intragastric bag volume. Metoclopramid given as a 10 mg i.v. bolus dose during the infusion of dopamine significantly decreased the intragastric bag volume, but 10 mg of metoclopramid i.v. before the dopamine infusion did not influence the bag volume per se. Dopamine decreases gastric tone in a dose-related manner and 10 mg of the dopamine-antagonist metoclopramid is not enough to fully reverse these effects.
    Acta Anaesthesiologica Scandinavica 09/1999; 43(7):722-5. · 2.36 Impact Factor
  • N G Levein, S E Thörn, M Wattwil
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    ABSTRACT: Dopamine decreases gastric tone and may therefore influence gastrointestinal motility. The aim of this investigation was to study the effects of a continuous infusion of dopamine on gastric emptying and orocaecal transit time. Nine healthy male volunteers were studied on two occasions in a randomized order. All volunteers received on separate days a continuous infusion of dopamine 5 micrograms kg-1 min-1 on one occasion and normal saline on the other occasion. Gastric emptying was measured by the paracetamol absorption test and orocaecal transit time by the hydrogen breath test. During the dopamine infusion the area under the paracetamol concentration curve was significantly smaller than during control conditions (P = 0.02). Orocaecal transit time was prolonged during the dopamine infusion (P = 0.02). Dopamine delays gastric emptying and prolongs orocaecal transit time.
    European Journal of Anaesthesiology 05/1999; 16(4):246-50. · 2.79 Impact Factor
  • S.-E. Thorn, N.-G. Levein, M. Wattwil
    Anesthesiology 01/1997; 87. · 5.16 Impact Factor