Minimum end-tidal sevoflurane concentration necessary to prevent movement during a constant rate infusion of morphine, or morphine plus dexmedetomidine in ponies.
Vet Anaesth Analg
; 41(2): 212-9, 2014 Mar.
Article
en En
| MEDLINE
| ID: mdl-24119016
OBJECTIVE: To compare the effects of a constant rate infusion (CRI) of dexmedetomidine and morphine to those of morphine alone on the minimum end-tidal sevoflurane concentration necessary to prevent movement (MACNM ) in ponies. STUDY DESIGN: Prospective, randomized, crossover, 'blinded', experimental study. ANIMALS: Five healthy adult gelding ponies were anaesthetized twice with a 3-week washout period. METHODS: After induction of anaesthesia with sevoflurane in oxygen (via nasotracheal tube), the ponies were positioned on a surgical table (T0), and anaesthesia was maintained with sevoflurane (Fe'SEVO 2.5%) in 55% oxygen. Monitoring included pulse oximetry, electrocardiography and measurement of anaesthetic gases, arterial blood pressure and body temperature. The ponies were mechanically ventilated and randomly allocated to receive IV treatment M [morphine 0.15 mg kg⻹ (T10-T15) followed by a CRI (0.1 mg kg⻹ hour⻹)] or treatment DM [dexmedetomidine 3.5 µg kg⻹ plus morphine 0.15 mg kg⻹ (T10-T15) followed by a CRI of dexmedetomidine 1.75 µg kg⻹ hour⻹ and morphine 0.1 mg kg⻹ hour⻹]. At T60, a stepwise MACNM determination was initiated using constant current electrical stimuli at the skin of the lateral pastern region. Triplicate MACNM estimations were obtained and then averaged in each pony. Wilcoxon signed-rank test was used to detect differences in MAC between treatments (α = 0.05). RESULTS: Sevoflurane-morphine MACNM values (median (range) and mean ± SD) were 2.56 (2.01-4.07) and 2.79 ± 0.73%. The addition of a continuous infusion of dexmedetomidine significantly reduced sevoflurane MACNM values to 0.89 (0.62-1.05) and 0.89 ± 0.22% (mean MACNM reduction 67 ± 11%). CONCLUSION AND CLINICAL RELEVANCE: Co-administration of dexmedetomidine and morphine CRIs significantly reduced the MACNM of sevoflurane compared with a CRI of morphine alone at the reported doses.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Dexmedetomidina
/
Caballos
/
Éteres Metílicos
/
Morfina
Límite:
Animals
Idioma:
En
Revista:
Vet Anaesth Analg
Asunto de la revista:
ANESTESIOLOGIA
/
MEDICINA VETERINARIA
Año:
2014
Tipo del documento:
Article
País de afiliación:
Bélgica
Pais de publicación:
Estados Unidos