Dopexamine but not dopamine increases gastric mucosal oxygenation during mechanical ventilation in dogs

TWL Scheeren*, LA Schwarte, SA Loer, O Picker, A Fournell

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

28 Citations (Scopus)

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 languageEnglish
Pages (from-to)881-887
Number of pages7
JournalCritical Care Medicine
Volume30
Issue number4
DOIs
Publication statusPublished - Apr-2002
Externally publishedYes
Event12th Annual Congress of the European-Society-of-Intensive-Care-Medicine - BERLIN, Berlin, Germany
Duration: 3-Oct-19996-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

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