Cardiovascular effects of two adenosine constant rate infusions in anaesthetized dogs.
Joerger FBDepartment of Clinical Diagnostics and Services, Division of Anaesthesiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland. Electronic address: fjoerger@vetclinics.uzh.ch.
Dennler MDepartment of Clinical Diagnostics and Services, Clinic of Diagnostic Imaging, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Meira CDepartment of Clinical Diagnostics and Services, Division of Anaesthesiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Mosing MDepartment of Clinical Diagnostics and Services, Division of Anaesthesiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland; College of Veterinary Medicine, School of Veterinary and Life Sciences, Murdoch University, Perth, Australia.
Richter HDepartment of Clinical Diagnostics and Services, Clinic of Diagnostic Imaging, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
Ringer SKDepartment of Clinical Diagnostics and Services, Division of Anaesthesiology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland.
English
OBJECTIVE Adenosine induces vasodilatation. The aim of this study was to investigate cardiovascular effects of two adenosine constant rate infusion (CRI) doses in dogs.
STUDY DESIGN Experimental, longitudinal repeated measure design.
ANIMALS Ten healthy purpose-bred Beagle dogs.
METHODS Each dog was sedated with butorphanol. Anaesthesia was induced with propofol intravenously and maintained with sevoflurane (inspired oxygen fraction = 47-55%). Controlled mechanical ventilation was used to maintain normocapnia. Two doses of adenosine were administered as CRIs to each dog: 140 μg kg-1 minute-1 (A140) followed by 280 μg kg-1 minute-1 (A280). Pulse rate, invasive arterial pressure and stroke volume (by magnetic resonance phase contrast angiography) were measured at baseline, 3 minutes after starting adenosine and 3 and 10 minutes after discontinuing adenosine. Cardiac output, cardiac index and approximated systemic vascular resistances (approximate SVR) were calculated. Additionally, arterial blood gases, co-oximetry, electrolytes, glucose and lactate were measured and oxygen content and delivery calculated. One-way repeated measures analysis of variance (p < 0.05) was used for data analysis.
RESULTS A140 and A280 resulted in a significant decrease in arterial blood pressure [systolic (p = 0.008), mean (p = 0.003), and diastolic arterial pressure (p = 0.004)] and approximate SVR (p = 0.008) compared with baseline. No significant changes were detected for the other variables. All values returned to baseline within 3 minutes after adenosine discontinuation.
CONCLUSIONS AND CLINICAL RELEVANCE Adenosine CRI decreases arterial pressure by vasodilatation in healthy dogs. No additional effects were observed with the higher dose. The effects in compromised dogs remain to be investigated.