[Comparison of two methods of local anaesthesia for laparotomy in cattle]

To compare the feasibility and efficacy of two methods of local anaesthesia with procaine 2% for flank laparotomy in cattle. MATERIAL UND METHODS: A total of 100 cattle undergoing laparotomy were divided into two groups of 50: one group underwent a modified infiltration anaesthesia (MIA) technique consisting of an incisional line block combined with an inverted L-block, and the other group underwent proximal paravertebral anaesthesia (PPVA). Indications for laparotomy were displaced abomasum, caecal disorders, rumenotomy and exploratory laparotomy. The two methods were compared with regard to the reaction of the cows to the application of anaesthesia, the degree of difficulty and the amount of time and anaesthetic agent required. The reactions of the cattle to incision of the various layers of the abdominal wall, abdominal exploration and surgical closure of the abdomen were assessed.

Both techniques required a mean of 8 minutes to complete but the MIA method was considered more difficult than the PPVA (p=0.13). The PPVA required significantly (p<0.001) less procaine than the MIA (144 vs. 195ml). Comparison of the two techniques with respect to different types of pain reactions (no reaction, non-specific reaction, specific reaction) during cutting of the different layers of the abdominal wall revealed that PPVA provided significantly (p=0.01) better analgesia than the MIA. After PPVA, pain reactions to incision of the external oblique abdominal muscle were more severe, but reactions to abdominal exploration and to suturing the two oblique abdominal muscles were significantly (p<0.05) milder than after MIA.

Neither technique resulted in consistent and complete elimination of pain reactions in every patient, but overall PPVA had better results than the MIA. The analgesic effect of both techniques could be improved by repeated administration of procaine and mild tranquillization (Xylazine; 0.01mg/kg i.v.) before laparotomy. For PPVA, a combination of procaine and epinephrine should be used. It would be advantageous to have anaesthetic agents, e.g. lidocaine, that are more potent than procaine 2% for local analgesia in cattle.