Robert W Arnold1, Russell E Biggs2, Brion J Beerle2. 1. Alaska Children's EYE & Strabismus, Anchorage, Alaska. Electronic address: eyedoc@alaska.net. 2. Chugach Anesthesia, Anchorage, Alaska.
Abstract
BACKGROUND: We reported that premedication with nasal dexmedetomidine was associated with a more intense oculocardiac reflex (OCR). In this study we performed an intrasubject, intravenous comparison to test our hypothesis that this alpha-adrenergic agonist potentiates the trigemino-vagal reflex. METHODS: OCR (greatest change heart rate/baseline heart rate) was prospectively monitored with 10-second, square-wave 200 g tension on the inferior rectus or other muscles during strabismus surgery. Between the first and second muscle, intravenous dexmedetomidine 0.5 μg/kg was delivered. RESULTS: All patients had no anticholinergic agents. A total 842 historic control patients (median age, 5.5 years) with no dexmedetomidine between muscles experienced the first OCR of 75% ± 24% (SD) and the second OCR of 77% ± 22%. The 33 study patients (median age, 5.6 years) experienced the first OCR 84% ± 16% and dexmedetomidine second OCR of 66% ± 25% for a bradycardia augmentation of 18% ± 19% (P < 0.01 [Mann-Whitney]). CONCLUSIONS: Similar to the effect of fentanyl, intravenous fast-push dexmedetomidine augmented the bradycardia associated with extraocular muscle traction.
BACKGROUND: We reported that premedication with nasal dexmedetomidine was associated with a more intense oculocardiac reflex (OCR). In this study we performed an intrasubject, intravenous comparison to test our hypothesis that this alpha-adrenergic agonist potentiates the trigemino-vagal reflex. METHODS: OCR (greatest change heart rate/baseline heart rate) was prospectively monitored with 10-second, square-wave 200 g tension on the inferior rectus or other muscles during strabismus surgery. Between the first and second muscle, intravenous dexmedetomidine 0.5 μg/kg was delivered. RESULTS: All patients had no anticholinergic agents. A total 842 historic control patients (median age, 5.5 years) with no dexmedetomidine between muscles experienced the first OCR of 75% ± 24% (SD) and the second OCR of 77% ± 22%. The 33 study patients (median age, 5.6 years) experienced the first OCR 84% ± 16% and dexmedetomidine second OCR of 66% ± 25% for a bradycardia augmentation of 18% ± 19% (P < 0.01 [Mann-Whitney]). CONCLUSIONS: Similar to the effect of fentanyl, intravenous fast-push dexmedetomidine augmented the bradycardia associated with extraocular muscle traction.
Authors: Emily M David; Cholawat Pacharinsak; Katechan Jampachaisri; Lisa Hagan; James O Marx Journal: J Am Assoc Lab Anim Sci Date: 2022-08-08 Impact factor: 1.706
Authors: August C Schumacher; Michelle L Ball; Andrew W Arnold; Robin L Grendahl; R Kevin Winkle; Robert W Arnold Journal: Clin Ophthalmol Date: 2020-12-04