The incidence of post-anesthetic lameness in 655 horses undergoing 733 anesthetic episodes over a 3 year period was 6.4%. Nineteen factors previously reported or proposed to play a role in the development of post-anesthetic lameness were evaluated statistically. Only hypotension and the duration of the anesthetic period were significant factors.

Objective: The purpose of this study was to determine the effect of timing of analysis, collection tube type and repeated opening of sample tubes on venous PCO2, pH, HCO3, and base excess (BE) results. Design: Prospective experimental study, paired sample analysis. Setting: Veterinary Medical Teaching Hospital. Animals: Twenty dogs. Interventions: Jugular venous blood samples. Measurements and main results: PCO2, pH, HCO3, and BE were determined immediately following collection (control) and at selected times up to 30 minutes after placement in either screw top or vacuum heparin collection tubes. A different set of screw top and vacuum heparin collection tubes were sampled repeatedly over time for up to 15 minutes. In the screw top delayed analysis group, only pH changed significantly at one time point. PCO2 decreased significantly in all other groups and resulted in a significant reciprocal pH change in the vacuum tubes with either delayed single analysis or repeated sampling. HCO3 and BE declined significantly in multi‐sampled vacuum tubes and HCO3 also decreased significantly in multi‐sampled screw top tubes. Conclusions: Analysis of acid–base status is optimally performed on freshly drawn blood. However, when it is anticipated there will be a delay in analysis of samples kept at room temperature, the use of 2.0 mL plastic screw top heparin anticoagulant tubes may result in fewer pre‐analytical errors than 3.5 mL glass vacuum tubes.

The cardiorespiratory effects of four opioid-tranquilizer combinations were evaluated in six dogs. The four combinations were administered to each dog in a randomized order. Buprenorphine (BUP; 0.01 mg/kg IV) or oxymorphone (OXY; 0.1 mg/kg IV) was followed in 10.4 +/- 1.3 minutes by midazolam (MID; 0.3 mg/kg IV) or acepromazine (ACE; 0.05 mg/kg IV). Nalbuphine (0.16 mg/kg IV) was administered 94.1 +/- 2.3 minutes after the tranquilizer was given. Heart rate (HR) and mean arterial blood pressure (MAP) decreased significantly (P < .05) after each combination. MAP was significantly lower with combinations using ACE. Most dogs panted after opioid administration; this was associated with increased minute volume (VM) and decreased tidal volume (VT). After administration of the tranquilizer, mean breathing rate and VM index (VMI) were significantly lower with ACE combinations. There were no significant changes in pH and blood gas variables after BUP-ACE. The other three combinations were associated with significant (P < .05) decreases in pH and increases in PaCO2. Mean PaO2 decreased significantly (P < .05) with OXY combinations but not BUP combinations. Dysrhythmias (atrial or ventricular escape complexes) were seen with each combination. HR increased significantly (P < .05) after nalbuphine in dogs receiving OXY, but not BUP. Dogs receiving OXY became more alert after nalbuphine on six of 12 occasions, whereas dogs receiving BUP became less alert on six of 12 occasions. OXY-ACE provided the most chemical restraint/sedation and BUP-MID provided the least.