Matt R. Read

Paravertebral block for forelimb anesthesia in the dog - an anatomic study.

OBJECTIVE To determine the anatomic landmarks for performing paravertebral forelimb block in the dog. STUDY DESIGN Technique description. ANIMALS Nine canine cadavers. METHODS Each intervertebral foramen between the C5 and T2 vertebrae was targeted. With the dog in lateral recumbency, a 20 SWG 3″ spinal needle was placed at a 45 degree angle from a vertical transverse plane (with the dog standing this plane would be perpendicular to the ground) 2-3 cm lateral to the median plane for the three cranial intervertebral foramina and at a 90 degree angle with the same transverse plane 2-3 cm lateral to the median plane for the T1-T2 intervertebral foramina. RESULTS Three out of nine (33%) of the cadavers had successful staining of all four desired nerves and the remaining six (66%) cadavers had successful staining of three of the four nerves. The C6-C7 spinal nerve was successfully stained in all nine cadavers. The other three nerves were each successfully stained in seven out of nine (78%) cadavers. CONCLUSIONS AND CLINICAL RELEVANCE The landmarks allow reliable placement of a solution at the nerves comprising the brachial plexus, allowing anesthesia of the entire forelimb in the dog.

Effects of acepromazine, hydromorphone, or an acepromazine-hydromorphone combination on the degree of sedation in clinically normal dogs

OBJECTIVE To determine the effects of IM administration of acepromazine, hydromorphone, or the acepromazine-hydromorphone combination on degree of sedation in clinically normal dogs and to compare 2 sedation scoring techniques. DESIGN Prospective, randomized, blinded, controlled trial. Animals-46 random-source dogs. PROCEDURES Dogs were assigned to receive IM administrations of acepromazine (0.05 mg/kg [0.023 mg/lb]; [DOSAGE ERROR CORRECTED] n = 12), hydromorphone (0.1 mg/kg [0.045 mg/lb]; 11), acepromazine-hydromorphone (0.5 mg/kg and 0.1 mg/kg, respectively; 12), or saline (0.9% NaCI) solution (0.05 mL/kg [0.023 mL/lb]; 11). Sedation scores were determined at 0 (time of administration), 15, 30, 45, and 60 minutes by use of a subjective scoring system (SSS) and a simple numeric rating scale (NRS). RESULTS Acepromazine caused significantly greater sedation than did saline solution at 15, 30, 45, and 60 minutes. Acepromazine-hydromorphone caused significantly greater sedation than did saline solution at 15, 30, 45, and 60 minutes and than did hydromorphone alone at 30 minutes. Hydromorphone alone did not cause significantly greater sedation than did saline solution. All treatments, including saline solution, caused significantly greater sedation at 45 and 60 minutes, compared with sedation at time 0. There was a significant correlation (r(2) = 0.72) between scores obtained with the SSS and NRS, but the NRS was less sensitive for detecting clinically important sedation. CONCLUSIONS AND CLINICAL RELEVANCE Administration of acepromazine or acepromazine-hydromorphone caused sedation in clinically normal dogs, whereas administration of hydromorphone alone did not. The NRS was a less-reliable measure of sedation.