Transcript REMIFENTANIL INTRAOPERATIVE ANALGESIA. A COMPARATIVE STUDY WITH FENTANYL IN DOGS

REMIFENTANIL INTRAOPERATIVE
ANALGESIA. A COMPARATIVE STUDY
WITH FENTANYL IN DOGS
Rubio M, Redondo JI, Carrillo JMª, Sopena JJ, Soler G*
Facultad de Ciencias Experimentales y de la Salud.Universidad Cardenal Herrera -CEU.Valencia
* Hospital Veterinario Marina Alta. Denia.Alicante
OBJECTIVES
The aim of this study was to evaluate the intraoperative analgesia of remifentanil in
dogs, comparing with fentanyl and a placebo solution as well as the study of the
haemodynamic and respiratory responses, and the patient recovery after two hours of
anesthesia.
MATERIAL Y METODO
1. Anesthetic protocol
Seven beagles dogs ASA I were anesthetized three times. All of them were
anesthetized with the following anesthetic protocol: medetomidine (10 g/kg IV),
propofol (3 mg/kg IV), sevoflurane and atracurium (150 g/kg IV), every 30
minutes. At the end of the procedure we reverted the effects of atracurium with a
combination of atropine (0.01 mg/kg) and neostigmine (5 g/kg) intravenous.
2. Analgesic protocol
Three different analgesic protocols were used and they were classified in
these groups:
• RMF: (remifentanil: 0,5 g/kg IV induction doses + 0,25 g/kg/min
maintenance doses).
• FEN: (fentanyl: 2 g/kg IV induction doses + 0,1 g/kg/min IV maintenance
doses).
• PCB (glucosade fluid infussion).
3. Postanesthetic protocol
The following postanesthetic analgesic protocol was used in all groups:
morphine (0,2 mg/kg IM) and meloxicam (0,2 mg/kg IV) 20 minutes before the end
of the procedure
4. Painful evaluation
During the procedure, several cardiovascular and respiratory variables were
studied every 5 minutes. Pain response was evaluated pinching with a forceps in
the back paws for 1 minute. It was found that the animals were painful when the
arterial pressure and heart rate increased by 10% in relation to the last measure.
Times and quality of the recuperation were also evaluated comparing all groups.
RESULTADOS
The results of the study showed that the RMF and FEN groups presented a
significantly lower EtSev than PCB group, with a decrease of 28.57% and 29,73%
respectively. RMF showed the highest values in arterial pressures and PVC and
intermediate values in heart rate and compliance. In this group, EtCO2 was lower
than in the others. The lowest values in heart rate and arterial pressures were
found in FEN group, while the highest heart rate and intermediate values in arterial
pressures were observed in PCB`s group.
The only value that was similar in the three groups was SpO2, because of the
animals were inhalating 100% O2.
The recuperation period was good and peaceful in all the animals, but recovery
times were significantly lower in RMF dogs.
CONCLUSIONES
Tanto el remifentanilo (Ultiva), como el fentanilo (Fentanest), son dos
fármacos útiles para proporcionar analgesia intraoperatoria en el perro.
Tanto el remifentanilo (Ultiva) como el fentanilo (Fentanest) producen un descenso
significativo del 28,57% y 29,73% respectivamente de la concentración mínima de
sevoflurano necesario para mantener un plano anestésico adecuado que aboliera la
respuesta del paciente a los estímulos dolorosos.
El remifentanilo (Ultiva) administrado en perfusión continua proporciona una mayor
estabilidad hemodinámica y cardiovascular que el fentanilo (Fentanest) administrado
de la misma forma.
Tras una anestesia de 120 minutos, la recuperación postoperatoria es suave, tranquila
y sin complicaciones en el 100% animales, mostrando el Grupo RMF tiempos de
recuperación significativamente inferiores a los grupos FEN y PCB.
El protocolo de meloxicam (Metacam)- morfina (cloruro mórfico) a las dosis
descritas proporciona una buena cobertura analgésica en el tratamiento del dolor
postoperatorio.
Dada la depresión respiratoria producida tanto por el remifentanilo (Ultiva), como por
el fentanilo (Fentanest) es muy recomendable emplear ventilación mecánica para
asegurar la correcta oxigenación y la normocapnia en los pacientes.