ULTRASONOGRAPHIC GUIDANCE IMPROVES SENSORY BLOCK AND ONSET TIME OF 3-IN-ONE BLOCKS

The use of ultrasound reduces the onset time improves the quality of s ensory block, and minimizes the risks associated with the supraclavicu lar approach for brachial plexus and stellate ganglion blockade. The p resent study was designed to evaluate whether ultrasound also facilita tes the approach for 3-in-1 blocks. Forty patients (ASA physical statu s II or III) undergoing hip surgery after trauma were randomly assigne d to two groups. In the ultrasound (US) group, 20 mt bupivacaine 0.5% was administered under US guidance, whereas in the control group, the same amount and concentration of local anesthetic was administered wit h the assistance of a nerve stimulator (NS). After US-or NS-based iden tification of the femoral nerve, the local anesthetic solution was adm inistered, and the distribution of the local anesthetic solution was v isualized and recorded on videotape in the US group. The quality and t he onset of the sensory block was assessed by using the pinprick test in the central sensory reg-ron of each of the three nerves and compare d with the same stimulation on the contralateral leg every 10 min for 60 min. The rating was performed using a scale from 100% (uncompromise d sensibility) to 0% (no sensory sensation). Heart rate, noninvasive b lood pressure, and oxygen saturation were measured at short intervals for 60 min. The onset of sensory blockade was significantly shorter in Group US compared with Group NS (US 16 +/- 14 min, NS 27 +/- 16 min, P < 0.05). The quality of the sensory block after injection of the loc al anesthetic was also significantly better in Group US compared with Group NS (US 15% +/- 10% of initial value, NS 27% +/- 14% of initial v alue, P < 0.05). A good analgesic effect was achieved in 95% of the pa tients in the US group and in 85% of the patients in the NS group. In the US group, visualization of the cannula tip, the femoral nerve, the major vessels, and the local anesthetic spread was possible in 85% of patients. Incidental arterial puncture (n = 3) was observed only in t he NS group. We conclude that an US-guided approach for 3-in-1 block r educes the onset time, improves the quality of the sensory block and m inimizes the risks associated with this regional anesthetic technique. Implications: The onset time and the quality of a regional anesthetic technique for the lower extremity is improved by ultrasonographic ner ve identification compared with older techniques.