Balanced anesthesia and ventilation strategies for an alpaca (Lama pacos) with an increased anesthetic-risk.

We report the use of a balanced anesthetic technique in a three-year-old, female Huacaya alpaca with an increased anesthetic risk that underwent an extensive dental surgery. Anesthesia was provided with an infusion of midazolam, fentanyl, S-ketamine and low concentrations of isoflurane in oxygen. The mandibular alveolar nerve was desensitized with a lidocaine-bupivacaine combination. The alpaca showed signs of hypoxemia fifteen minutes after anesthesia induction and arterial blood gases confirmed severe venous admixture. Application of positive end expiratory pressure (PEEP) of 6-9 cm H2O improved the arterial oxygenation. Other cardiopulmonary variables remained within the normal range. At the end of surgery, sarmazenil was administered to antagonize the effects of midazolam and emergence from anesthesia was smooth and uneventful. Flunixine meglumine and a transdermal delivery system for fentanyl were administered for post-operative analgesia. This method of balanced anesthesia allowed for an adequate anesthetic plane and a safe recovery, however, special ventilation strategies (PEEP) had to be applied.