[Model establishment for emulsified isoflurane delivered selectively to the goat spinal cord and preliminary research on the immobility mechanism of isoflurane].

OBJECTIVE

To develop a new model of preferentially delivering isoflurane to the goat spinal cord, and to explore preliminarily volatile anesthetic action sites.

METHODS

Eighteen goats were randomly and equally divided into group artery and group vein. In group artery, emulsified isoflurane was infused into descending aorta for developing the model to deliver isoflurane to the goat spinal cord. In group vein, emulsified isoflurane was infused via the ear vein. After the end-tidal isoflurane concentration of 1 minimum alveolar concentration (MAC) was maintained for 20 min, the isoflurane partial pressures (P(iso)) in samples which were drawn from the femoral artery and the carotid artery were determined by a gas chromatography.

RESULTS

In group vein, there was no statistical difference among all the P(iso). In group artery, the P(iso) of the femoral arterial blood was almost same as that in group vein, but the P(iso) of the carotid arterial blood was near half of that in group vein [(6.07 +/- 3.60) mmHg vs (10.21 +/- 2.41) mmHg, P < 0.05].

CONCLUSION

This new model permits preferentially to deliver the isoflurane to the in situ goat spinal cord, and the results support the importance of the spinal cord in suppressing nociceptive reflex under isoflurane anesthesia.