Cardiopulmonary effects of an infusion of remifentanil or morphine in horses anesthetized with isoflurane and dexmedetomidine

Is there a place for dexmedetomidine in equine anaesthesia and analgesia? A systematic review (2005–2017)

“…A blinded, randomized, cross‐over study with three treatments, a saline and the two dexmedetomidine CRIs, would have been more appropriate. Under general anaesthesia, the limited cardiopulmonary effects of dexmedetomidine CRIs ranging from 1 to 1.75 μg kg −1 hr −1 were confirmed in both experimental (Benmansour et al., ) and clinical studies (Marcilla et al., ). Whereas the low dose was used in combination with different opioid infusions (Benmansour et al., ), the use of the higher rate was justified by its theoretically higher sedative, analgesic and inhalant sparing effects (Marcilla et al., ).…”

“…In another clinical, blinded, randomized study involving 20 adults, healthy, client-owned horses, the same protocol, 3.5 μg/ kg sedation dose followed by a CRI at 1.75 μg kg −1 hr −1 , seemed to be more adequate than a morphine-based technique (0.15 mg/kg added to the dexmedetomidine sedation dose, followed by a mor- A 1.5 μg kg −1 hr −1 CRI, without loading dose and after sedation with xylazine and anaesthetic maintenance with sevoflurane and remifentanil, was successfully used in a 10-year-old horse for a radical mandibulectomy which lasted for 13 hr (Benmansour & Duke-Novakovski, 2013). In a 60-min experimental, nonblinded, randomized, cross-over, study involving six adults, healthy, isoflurane-anaesthetized horses, no significant differences in cardiopulmonary effects and recovery qualities were detected between a dexmedetomidine CRI alone (loading dose 0.25 μg/kg followed by a CRI of 1 μg kg −1 hr −1 ) and combined with morphine (0.15 mg/kg plus a 0.1 mg kg −1 hr −1 infusion) or remifentanil, CRI at 6 μg kg −1 hr −1 (Benmansour et al, 2014).…”

“…A 1.5 μg kg −1 hr −1 CRI, without loading dose and after sedation with xylazine and anaesthetic maintenance with sevoflurane and remifentanil, was successfully used in a 10‐year‐old horse for a radical mandibulectomy which lasted for 13 hr (Benmansour & Duke‐Novakovski, ). In a 60‐min experimental, nonblinded, randomized, cross‐over, study involving six adults, healthy, isoflurane‐anaesthetized horses, no significant differences in cardiopulmonary effects and recovery qualities were detected between a dexmedetomidine CRI alone (loading dose 0.25 μg/kg followed by a CRI of 1 μg kg −1 hr −1 ) and combined with morphine (0.15 mg/kg plus a 0.1 mg kg −1 hr −1 infusion) or remifentanil, CRI at 6 μg kg −1 hr −1 (Benmansour et al., ). No excitement or colic was seen in the recovery.…”

Cardiopulmonary Effects and Recovery Quality of Remifentanil–Isoflurane Anesthesia in Horses

“…During the postanesthetic period, no clinically detectable recovery problems or gastrointestinal problems were identified. The conclusion was dexmedetomidine alone or in combination with remifentanil or morphine infusions was infused for 60 minutes without adverse effects in the six healthy isoflurane-anesthetized horses [12].…”

“…The assumption is that remifentanil and fentanyl have similar potency in horses [11,12]. The peak analgesic effect is produced 1-3 minutes after the administration of the drug, which is faster than that produced by fentanyl.…”