Comparison of the efficiency of anatomical and ultrasound-guided method for the Th₄-Th₇ intercostal nerve block in dogs.

摘要

The aim of this study was the assessment of the usefulness of the ultrasound-guided method during injections into the Th₄-Th₇ intercostal nerve area in dogs, as well as comparison of the liquid deposition precision obtained using anatomical and ultrasound-guided methods. The study has been performed on fresh cadavers of 20 dogs. A mixture of black ink and iodinated contrast medium was injected. The procedure was performed by anatomical method at the right side and ultrasound-guided at the left side. Subsequently, thoracic radiograph in dorsal recumbency and post-mortem examination were performed. A spread of the contrast media mixture was assessed on radiographs and during post-mortem examinations. Eighty injections were done in 20 dogs with the use of each method. The assessment method of the accurate placement of the contrast medium mixture in the area of the intercostal nerve, based on X-ray examination, was consistent with necropsy findings. Probability of the precise liquid placement was two times greater in case of ultrasound-guided method than in case of anatomical one. These differences were statistically significant. Ultrasound viewing improved considerably the precision of injection of the contrast medium mixture in the area of intercostal nerves. This technique is simple and easy to master and it increases effectiveness and safety of performed procedures. The comparison of both methods on cadavers enables a choice of an appropriate anaesthesia technique in living animals.