Butorphanol with oxygen insufflation corrects etorphine-induced hypoxaemia in chemically immobilized white rhinoceros (Ceratotherium simum)

Abstract

BackgroundOpioid-induced immobilization is associated with severe respiratory depression in the white rhinoceros. We evaluated the efficacy of butorphanol and oxygen insufflation in alleviating opioid-induced respiratory depression in eight boma-managed rhinoceros.ResultsChemical immobilization with etorphine, azaperone and hyaluronidase, as per standard procedure for the white rhinoceros, caused severe respiratory depression with hypoxaemia (PaO2 = 27 ± 7 mmHg [mean ± SD]), hypercapnia (PaCO2 = 82 ± 6 mmHg) and acidosis (pH =7.26 ± 0.02) in the control trial at 5 min. Compared to pre-intervention values, butorphanol administration (without oxygen) improved the PaO2 (60 ± 3 mmHg, F(3,21) =151.9, p <0.001), PaCO2 (67 ± 4 mmHg, F(3,21) =22.57, p <0.001) and pH (7.31 ± 0.06, F(3,21) =27.60, p <0.001), while oxygen insufflation alone exacerbated the hypercapnia (123 ± 20 mmHg, F(3,21) =50.13, p <0.001) and acidosis (7.12 ± 0.07, F(3,21) =110.6, p <0.001). Surprisingly, butorphanol combined with oxygen fully corrected the opioid-induced hypoxaemia (PaO2 = 155 ± 53 mmHg) and reduced the hypercapnia over the whole immobilization period (p <0.05, areas under the curves) compared to the control trial. However, this intervention (butorphanol + oxygen) did not have any effect on the arterial pH.ConclusionsOxygen insufflation combined with a single intravenous dose of butorphanol improved the immobilization quality of boma-managed white rhinoceros by correcting the opioid-induced hypoxaemia, but did not completely reverse all components of respiratory depression. The efficacy of this intervention in reducing respiratory depression in field-captured animals remains to be determined.

Nalbuphine and butorphanol reverse opioid-induced respiratory depression but increase arousal in etorphine-immobilized goats (Capra hircus)

“…; Haw et al. ). We therefore compared butorphanol with nalbuphine because results from studies in mice (Schmidt et al.…”

“…In wildlife immobilization, butorphanol is used to reverse etorphine-induced respiratory depression, especially in opioid-sensitive species, such as the white rhinoceros (Burroughs et al 2012). However, recent studies indicate that butorphanol is not an effective l-antagonist in rhinoceros as was previously thought (Miller et al 2013;Haw et al 2014). Evidence from human and rodent studies indicates that nalbuphine, which is not currently used in veterinary medicine, may be a better l-opioid antagonist than butorphanol (Pallasch & Gill 1985;Schmidt et al 1985;Zucker et al 1987).…”

“…However, in non-human primates, butorphanol has been characterized as a low-efficacy l-receptor agonist, rather than as a l-antagonist (Butelman et al 1995;Vivian et al 1999). Recent studies in white rhinoceros have also shown that the beneficial effects of butorphanol on respiratory parameters are related to a decrease in immobilization level more than they are to antagonism of l-opioid-induced hypoventilation (Miller et al 2013;Haw et al 2014). We therefore compared butorphanol with nalbuphine because results from studies in mice (Schmidt et al 1985) and humans (Bowdle et al 1987) indicated that nalbuphine may be a more potent l-antagonist than butorphanol.…”

“…; Haw et al. ). Evidence from human and rodent studies indicates that nalbuphine, which is not currently used in veterinary medicine, may be a better μ‐opioid antagonist than butorphanol (Pallasch & Gill ; Schmidt et al.…”

Ampakine CX1942 attenuates opioid-induced respiratory depression and corrects the hypoxaemic effects of etorphine in immobilized goats (Capra hircus)

“…We have thus demonstrated that CX1942 attenuates etorphine-induced respiratory depression in goats, and that it may be useful for improving the welfare of immobilized wild ungulates. Previous studies investigating the effects of etorphine on respiratory and cardiovascular systems have used goats as a model for wild ungulates because the use of a domesticated animal in a controlled setting limits the confounding effects of a capture-induced stress response, and allows for the better determination of a drug's pharmacodynamic effects (Heard et al 1990(Heard et al , 1996Buss & Meltzer 2001;Meyer et al 2015). However, the degree of sensitivity to opioid-induced respiratory depression varies amongst species (Burroughs et al 2012).…”