Comparison of time to loss of consciousness and maintenance of anesthesia following intraosseous and intravenous administration of propofol in rabbits.

OBJECTIVE

To compare time to loss of consciousness (LOC) and effective maintenance of anesthesia following intraosseous (IO) and IV administration of propofol in rabbits.

DESIGN

Evaluation study.

ANIMALS

24 New Zealand White rabbits.

PROCEDURES

Rabbits were selected to receive IO (n = 6) or IV (6) bolus administration of 1% propofol (12.5 mg/kg [5.67 mg/lb]) only or an identical bolus of propofol IO (6) or IV (6) followed by a constant rate infusion (CRI; 1 mg/kg/min [0.45 mg/lb/min]) by the same route for 30 minutes. Physiologic variables were monitored at predetermined time points; time to LOC and durations of anesthesia and recovery were recorded.

RESULTS

Following IO and IV bolus administration, mean time to LOC was 11.50 and 7.83 seconds, respectively; changes in heart rate, respiratory rate, oxygen saturation (as measured by pulse oximetry), and mean arterial blood pressure values were evident, but findings did not differ between groups. For the IO- and IV-CRI groups, propofol-associated changes in heart rate, oxygen saturation, and mean arterial blood pressure values were similar, and although mean arterial blood pressure decreased significantly from baseline, values remained > 60 mm Hg; respiratory rate decreased significantly during CRI in both groups, but remained higher in the IO-CRI group. Anesthesia and recovery time did not differ between the IO- and IV-CRI groups.

CONCLUSIONS AND CLINICAL RELEVANCE

In all evaluated aspects of anesthesia, IO administration of propofol was as effective as IV administration in rabbits. Results suggested that total IO anesthesia can be performed in rabbits with limited vascular access.