RADIOLOGICAL APPEARANCE OF AIR INTRODUCED DURING EQUINE REGIONAL LIMBANESTHESIA

Twelve horses were injected intra-articularly into the metacarpophalan geal joint and extra-articularly in the region of the lateral palmar d igital nerve with 1 ml air and local anaesthetic to simulate gas accid entally introduced during regional anaesthesia, Half the horses underw ent limited exercise after which all horses were radiographed at 15 an d 45 min and then every 24 h until all evidence of gas had disappeared . Intra-articular gas appeared as gas capped radiolucencies (GCR) in t he proximal aspect of the joint. Extra-articular gas appeared as linea r radiolucencies (LR) which initially tended to migrate proximally. Th ere was no significant difference in gas resorption in exercised and n onexercised horses, All gas was resorbed within 96 h with most of the gas already gone at 48 h.