The effect of low dose rocuronium on globe position, muscle relaxation and ventilation in dogs: a clinical study.
OBJECTIVE
The purpose of this study was to evaluate globe position, muscle relaxation and changes in ventilatory parameters after intravenous administration of 0.1 mg/kg rocuronium.


METHODS
Prospective clinical study.


METHODS
Sixteen dogs of different breeds, with a body weight of 22.1 +/- 13 kg and age of 5.6 +/- 2.8 years (mean +/- SD), were anesthetized for a short ophthalmic examination requiring central position of the globe.


METHODS
All dogs were premedicated with 0.005 mg/kg medetomidine and 0.1 mg/kg methadone IV. Anesthesia was induced with propofol to effect and maintained with 10 mg/kg/h propofol by continuous rate infusion. Following endotracheal intubation all dogs breathed 100% oxygen via an anesthetic circle system. Neuromuscular function was assessed with an acceleromyograph (TOF-Guard, Organon Teknika NV, Turnhout, Belgium) and by stimulation of the nervus peroneus superficialis. The ventilation parameters were measured using spirometry and capnography. After baseline measurements 0.1 mg/kg rocuronium was administered IV. Minute volume (MV), tidal volume (Vt), respiratory rate (RR), end expiratory carbon dioxide concentration (PE'CO(2)) and maximal depression of the response of the first twitch (T1) of train-of-four (TOF) stimulation and train-of-four ratio (TOFR) was measured. The change in the position of the globe was recorded.


RESULTS
T1 decreased to 61 +/- 18% and the TOF ratio to 45 +/- 21% of baseline values. Both parameters returned to baseline after 9 min. There was no significant reduction in MV, TV and RR and no increase in PE'CO(2). The globe rotated to a central position of 45 +/- 7.7 s after administration of rocuronium and remained there for 23 +/- 10.8 min in all dogs.


CONCLUSIONS
Rocuronium administered intravenously at a dose of 0.1 mg/kg to dogs causes a central position of the globe but minimal impairment of ventilation parameters.
Auer
Ulrike
U
Clinic of Anesthesiology and Perioperative Intensive Care, University of Veterinary Medicine, Vienna, Austria. ulrike.auer@vu-wien.ac.at
Mosing
Martina
M
Moens
Yves P S
YP
D000732:Androstanols / Q000494:pharmacology*; D000758:Anesthesia / Q000379:methods / Q000662:veterinary*; D000818:Animals; D002245:Carbon Dioxide / Q000032:analysis; D004285:Dogs / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005260:Female; D007262:Infusions, Intravenous / Q000662:veterinary; D008297:Male; D009126:Muscle Relaxation / Q000187:drug effects*; D003473:Neuromuscular Nondepolarizing Agents / Q000494:pharmacology*; D013508:Ophthalmologic Surgical Procedures / Q000662:veterinary; D012119:Respiration / Q000187:drug effects*; D000077123:Rocuronium; D013990:Tidal Volume
D000732:Androstanols; D003473:Neuromuscular Nondepolarizing Agents; D002245:Carbon Dioxide; D000077123:Rocuronium