Celiac plexus block in equine ileus : A pilot study

Celiac plexus block (CPB) is considered useful for the treatment of abdominal pain and for postoperative ileus. The aim of this study was to determinate feasibility and efficacy of the CPB in horses with ileus or postoperative ileus. Nine horses with decreased/absent small intestinal motility, confirmed by ultrasound ab- dominal examination, were enrolled. A numerical descriptive "motility scale" was used to identify motility degree: 0= absence of intestinal motility, 1= slight intestinal contraction, some less dilated loops, no ingesta movement. 2= contractions of at least 50% intestinal loops, 3= normal intestinal motility, 4= hypermotility. Under ultrasound guidance, a spinal needle (20 SWG x 120 mm) was inserted for all its length, between transverse processes of L1-L2 in dorso-ventral direction, parasaggital to the spinous processes, approxi- mately 8-10 cm abaxially. To verify the exact retroperitoneal position two drops of saline were positioned in the needle cone. If these were aspirated by the intra-abdominal negative pressure, the needle was slightly retracted and lidocaine 1% (40 ml) and ropivacaine 1% (10 ml) were injected on both sides. After 30-45 minutes, ultrasound examination was performed to evaluate the intestinal motility. For each horse, CPB was performed every 6 hours for 48h. HR, RR, gastric reflux, haematocrit, intestinal motility, appetite, defecation and bilateral flank sweating, were recorded before and after every CPB. Eight patients underwent surgery, 1 received only medical treatment. In 7/9 patients, ultrasound exami- nation demonstrated increases in intestinal motility, 2 patients reached a score of 3 within 48 hours. Mean "motility scale" score was respectively 0.5 ± 0.4 and 1.3 ± 0.6 before and after the block. In all horses after the CPB sweating of the flank was present bilaterally. The effectiveness of CPB is supposed to be due to the inhibition of vasoconstriction occurred in splanchnic organs as a consequence of sympathetic activation. To completely understand the mechanism trigged by the sympathetic block, an evaluation of intestinal my- oelectrical activity should be made. The correct positioning of the needle was always associated to flank sweating, increased intestinal motility, evaluated by ultrasound examination, progressive decrease of gastric reflux, increasing appetite and presence of feaces. This procedure can be used by veterinarians without great experience and also in situations that do not involve a hospital or ambulatory structure. Local anaesthetic combination takes advantage of the rapid onset (lidocaine), and prolonged duration (ropivacaine). Prelimi- nary results are promising, further studies will be performed.