Post-operative analgesia following thoracotomy in the dog: an evaluation of the effects of bupivacaine intercostal nerve block and nalbuphine on respiratory function.
Pain following thoracotomy reduces pulmonary ventilation in man and a similar effect is believed to occur in animals. The effects of two analgesic regimens on arterial blood gas parameters were studied in dogs following thoracotomy. Post-Operative analgesia was provided with intermittent nalbuphine, either alone or in combination with an intercostal nerve block using bupivacaine. Arterial blood gas analysis was carried out at 4, 8 and 16 h post-operatively, both before the administration of nalbuphine and again 30 min later. Animals which received nalbuphine alone had a significant rise in arterial oxygenation following administration of this analgesic. This effect was not observed at 4 and 8 h post-operatively in dogs which had an intercostal block with bupivacaine, but was seen at 16 h post-operatively when it could be anticipated that the effects of bupivacaine would have waned. These results suggest that intercostal block with bupivacaine can provide analgesia for over 8 h, and that the duration of action of nalbuphine in controlling post-operative pain in the dog is probably less than 4 h.
Flecknell
P A
PA
Comparative Biology Centre Medical School, Newcastle upon Tyne, UK.
Kirk
A J
AJ
Liles
J H
JH
Hayes
P H
PH
Dark
J H
JH
D000818:Animals; D001784:Blood Gas Analysis / Q000662:veterinary; D002045:Bupivacaine; D004285:Dogs; D007367:Intercostal Nerves; D009266:Nalbuphine; D009407:Nerve Block / Q000662:veterinary*; D010149:Postoperative Pain / Q000517:prevention & control*; D012119:Respiration / Q000187:drug effects*; D013908:Thoracotomy / Q000662:veterinary*
D009266:Nalbuphine; D002045:Bupivacaine