Chemical immobilization of wildlife often includes
opioids or cyclohexamines. These substances are problematic as a result of their required storage, handling, and record-keeping protocols. A potentially useful alternative sedation protocol includes a combination of
butorphanol,
azaperone, and
medetomidine (BAM: 0.43 mg/kg
butorphanol, 0.36 mg/kg
azaperone, 0.14 mg/kg
medetomidine). One risk of wildlife immobilization with any
drug combination is
hypoxemia. This may be of particular importance when using an alpha 2 agonist such as
medetomidine because of its powerful vasoconstrictive effect. In this prospective study, the BAM combination was evaluated for chemical immobilization of white-tailed deer. Additionally, selected physiologic parameters associated with BAM immobilization, including oxygen saturation via pulse oximetry and arterial blood gas measurement, with and without nasal insufflation of
oxygen at a relatively low flow of 3 L/min, were evaluated. The BAM combination resulted in a predictable onset of sedation, with a mean induction time to lateral recumbency of 9.8 +/- 3.6 min. All deer recovered smoothly within a range of 5-20 min after reversal with intramuscular administration of
naltrexone, atipamazole, and
tolazoline (
NAT). Clinically relevant decreases in arterial partial pressure of
oxygen (PaO2) and oxygen saturation (SpO2) were observed in animals not receiving supplemental
oxygen, while both parameters significantly improved for
oxygen-supplemented deer. Pulse oximetry with this protocol was an unreliable
indicator of oxygen saturation. In this study, altitude, recumbency,
hypoventilation,
butorphanol- and
medetomidine-specific effects, as well as the potential for alpha 2 agonist-induced pulmonary changes all may have contributed to the development of
hypoxemia. Overall, capture of white-tailed deer with the BAM/
NAT protocol resulted in excellent chemical immobilization and reversal. Because the BAM combination caused significant
hypoxemia that is unreliably detected by pulse oximetry but that may be resolved with nasal
oxygen insufflation, routine use of
oxygen supplementation is recommended.