Use of butorphanol and diprenorphine to counter respiratory impairment in the immobilised white rhinoceros (Ceratotherium simum)

Abstract

Opioid-induced immobilisation results in severe respiratory impairment in the white rhinoceros. It has therefore been attempted in the field to reverse this impairment with the use of opioid agonist-antagonists, such as nalorphine, nalbuphine, butorphanol and diprenorphine; however, the efficacy of some of these treatments has yet to be determined. The efficacy of butorphanol, either alone or in combination with diprenorphine both with and without oxygen insufflation, in alleviating opioid-induced respiratory impairment was evaluated. The study was performed in two parts: a boma trial and a field trial. Rhinoceroses were immobilised specifically for the study, according to a strict protocol to minimise confounding variables. A two-way analysis of variance was used to compare the physiological responses of the rhinoceroses to the different treatments and their effects over time. The intravenous administration of butorphanol (at 3.3 mg per mg etorphine) plus diprenorphine (at 0.4 mg per mg etorphine) did not offer any advantage over butorphanol (at 15 mg per mg etorphine) alone with regard to improving PaO2, PaCO2 and respiratory rates in etorphine-immobilised white rhinoceroses. Both butorphanol + diprenorphine + oxygen and butorphanol + oxygen, at the doses used, significantly improved the etorphine-induced hypoxaemia in both boma- and field-immobilised white rhinoceroses. Clinically acceptable oxygenation in field-immobilised white rhinoceroses can be achieved by using either treatment regimen, provided that it is combined with oxygen insufflation.

Odd haemoglobins in odd-toed ungulates: Impact of selected haemoglobin characteristics of the white rhinoceros (Ceratotherium simum) on the monitoring of the arterial oxygen saturation of haemoglobin

“…Acidosis, hypercapnia and a low arterial partial pressure of oxygen (PaO 2 ) are common in opioid-immobilised white rhinoceroses, indicating marked cardiorespiratory depression [1,4–6]. Our findings help to explain why despite the seemingly extremely low SaO 2 values reported in these animals, recovery is usually uneventful, without obvious clinical signs of long-term damage associated with such severe hypoxaemia.…”

“…Standard blood gas analysis and pulse oximetry indicate an alarmingly low oxygenation status under opioid immobilisation that is in conflict with uneventful recoveries [1,4–6]. Haymerle et al reported SaO 2 values as low as 39% and SpO 2 values as low as 42% in clinically healthy, opioid-immobilised animals generated by commercially available devices [7].…”

Midazolam Alters Acid-Base Status Less than Azaperone during the Capture and Transport of Southern White Rhinoceroses (Ceratotherium simum simum)

“…By the start of transport venous PCO 2 had decreased to normal values [ 33 ], which were maintained throughout the journey. Partial reversal of the etorphine by administering the opioid agonist-antagonists butorphanol and diprenorphine [ 24 ] and the change in body position, from lateral recumbency to standing, rapidly improved alveolar ventilation [ 13 ] and reduced hyper-metabolism [ 19 ]. These ventilatory changes likely had the greatest compensatory effects on the pH from TC to T0 but increases in HCO 3 − and BE at this time indicated that a blood intracellular chemical buffer response had also taken place [ 41 ].…”

“…Once the catheter was in place, butorphanol (butorphanol tartrate 50 mg/mL, Wildlife Pharmaceuticals) (5 mg per mg etorphine) was administered intravenously (IV) to partially antagonize the immobilizing effects of the etorphine and enable the rhinoceroses to walk into a transport crate [ 14 ]. Once in the crate, an IV bolus of diprenorphine (diprenorphine hydrochloride 12 mg/mL, Activon; Wildlife Pharmaceuticals) (3 mg per mg etorphine) was administered to further antagonize residual immobilizing, but not sedative, effects of the etorphine [ 24 ].…”

Do potent immobilising-opioids induce different physiological effects in impala and blesbok?

“…The small sample size is acknowledged as a limitation of this study. However, due to logistics, conservation status and ethical concerns, experiments in wildlife are often carried out with small numbers of 6 to 12 animals (Meyer et al 2018 ; Pfitzer et al 2019b ; Zeiler & Meyer 2017a ). Only healthy, adult animals which were adapted to captivity were part of this experiment.…”