Abstract
Objective:
To compare the effects of dopamine and dopexamine on gastric mucosal oxygenation during mechanical ventilation without and with positive end-expiratory airway pressure (PEEP) and after compensation of the PEEP-induced hemodynamic suppression.
Design:
Randomized controlled animal study.
Setting:
University research department of experimental anesthesiology.
Subjects:
Ten anesthetized dogs with chronically implanted ultrasound flow probes around the pulmonary artery for continuous measurement of cardiac output.
Interventions:
On different days, the dogs randomly received dopamine (2.5 and 5.0 mug(.)kg(-1.)min(-1), n = 10), dopexamine (0.5 and 1.0 mug(.)kg(-1.)min(-1)) without (n = 8) or with pretreatment with a selective beta(2)-adrenoceptor antagonist (ICI 118,551, n = 7), or saline (control, n = 7). To simulate common clinical situations, these interventions were performed during different ventilation modes: during mechanical ventilation without and with high levels of PEEP, and after compensation of the PEEP-induced systemic hemodynamic suppression by titrated volume resuscitation with hydroxyethyl starch.
Measurements and Main Results:
We continuously measured microvascular hemoglobin saturation (muHbo(2)) by light-guide spectrophotometry in the gastric mucosa. Dopexamine, but not dopamine, significantly increased gastric mucosal muHbo(2) by about 20%, regardless of the dose and the ventilation mode, Both catecholamines dose-dependently increased cardiac output and oxygen delivery by up to 75% without effects on systemic oxygen saturation. The effects of dopexamine on muHbo(2) as well as on cardiac output and oxygen delivery were prevented by selective beta(2)-adrenoceptor-blockade.
Conclusions:
Dopexamine but not dopamine improved gastric mucosal oxygenation in dogs. This effect was independent of the dosage and the ventilation mode. Thus, dopexamine may reverse a decrease in splanchnic oxygenation induced by ventilation with PEEP. The dopexamine-induced increase in gastric mucosal oxygenation was mediated by beta(2)-adrenoceptors, which explains the superior effects of dopexamine to dopamine on muHbo(2). The regional effects of both catecholamines were not mirrored by systemic hemodynamics.
Original language | English |
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Pages (from-to) | 881-887 |
Number of pages | 7 |
Journal | Critical Care Medicine |
Volume | 30 |
Issue number | 4 |
DOIs | |
Publication status | Published - Apr-2002 |
Externally published | Yes |
Event | 12th Annual Congress of the European-Society-of-Intensive-Care-Medicine - BERLIN, Berlin, Germany Duration: 3-Oct-1999 → 6-Oct-1999 |
Keywords
- catecholamines
- dopamine
- dopexamine
- gastric mucosal oxygenation
- monitoring
- spectrophotometry
- mechanical ventilation
- positive end-expiratory airway pressure
- mechanism of action
- animal study
- END-EXPIRATORY PRESSURE
- MULTIPLE ORGAN FAILURE
- MESENTERIC BLOOD-FLOW
- LIGHTGUIDE SPECTROPHOTOMETER EMPHO
- CARDIOPULMONARY BYPASS
- PORCINE MODEL
- TISSUE OXYGENATION
- CARDIAC-OUTPUT
- CRITICALLY ILL
- SEPTIC SHOCK