Possibilities of the ultrasound method in assessing the degree of swelling of perineural tissues at the level of the lower leg. Focus on regional anesthesia

Widespread introduction of ultrasound-guided regional anesthesia has increased the frequency of nerve blocks and the list of available nerves for blocking, particularly on the foot. In the area of the tibiocalcaneal joint, swellings of various etiologies are often found, including in patients with diabetes, who are characterized by high comorbidity. To date, the influence of edema on the effectiveness of local anesthetics is insufficiently studied. To evaluate the ultrasound criteria, we have analyzed and characterized the ultrasound pattern of 110 patients. When performing a nerve block in the area of the tibiocalcaneal joint, the time of the block onset and duration of sensory block in patients who underwent surgery for the diabetic foot depended reliably on the degree of ultrasound-diagnosed edema in the area of the block. The ultrasound method makes it possible to assess the degree of swelling in the area of blockade directly during conduction anesthesia. Further studies are needed to determine the root cause of this phenomenon, which may depend on the pH of the edema fluid or on dilution in the edema volume.