The precision of IBPB by use of the dual guidance technique may reduce the rate of Horner's syndrome. The higher water concentration in the prevertebral spaces of younger patients may create better conditions for the diffusion of ropivacaine, which may result in a statistically significant higher HS rate.

Background: Interscalene brachial plexus block is an effective regional anesthesia technique for shoulder surgeries. The superiority of the popular ultrasound-guided blocks over peripheral nerve stimulator-confirmed blocks remains unclear. In this study the efficacy of these different block techniques was compared. Methods: This prospective, randomized, clinical study included 109 patients (ASA grades I-III) who receive 20 mL 0.5% ropivacaine with ultrasound-guided blocks (U group), peripheral nerve stimulator-confirmed blocks (N group), or ultrasound-guided and peripheral nerve stimulator-confirmed blocks (dual guidance; NU group) for elective shoulder arthroscopy. Block onset time, duration, and effectiveness on the Lovett rating scale were assessed. Results: There was no statistically significant intergroup difference in duration of block performance, irrespective of the technique (P = 0.232). Onset time of complete warmth sensation loss (P < 0.001) and muscle strength abolition (P < 0.001) was significantly longer and mean Lovett rating scale score distribution was significantly higher in the N group than in the other groups (P < 0.001). These findings show a statistically significant correlation between the performance of the used block technique and the necessity of conversion to general anesthesia because of insufficient block in the N group (58.54%) than in the U (24.44%) and NU (19.57%) groups. Conclusions: Peripheral nerve stimulator-confirmed needle placement is not necessary to ensure effectiveness of ultrasound-guided blocks, which is expressed as a lack of necessity of conversion to general anesthesia. Nevertheless, the dual guidance technique is recommended to reduce the risk of complications and might be considered the regional anesthesia of choice for shoulder surgery.

Background: Shoulder arthroscopic procedures impose a challenge to anaesthesiologists in terms of postoperative analgesia. Proper pain management after arthroscopic procedures improves patient satisfaction and facilitates early rehabilitation. Methods: We performed a randomized, prospective clinical study to assess the influence of anthropometric parameters and IBPB technique on the quality of postoperative analgesia. A total of 106 randomly selected patients of ASA I-III status scheduled for elective shoulder arthroscopy. Reasons for exclusion were neurological deficit in the upper arm, allergies to amide-type local anesthetics, coagulopathy, and pregnancy.The patients received 20 mL of 0.5% ropivacaine for an ultrasound-guided interscalene brachial plexus block (IBPB) (group U), peripheral nerve stimulation (PNS)-confirmed IBPB (group N), or ultrasound-guided, PNS-confirmed IBPB (dual guidance; group NU). Results: We observed that the three groups did not differ in mean time of sensory and motor block terminations. In individual cases in each group, sensory block lasted up to 890-990 minutes, providing satisfactory long lasting postoperative analgesia in patients receiving IBPB. We observed a negative correlation between body mass index and termination of motor block (P = 0.037, Pearson's correlation coefficient) and a positive correlation between age and termination of sensory block (P = 0.0314, Pearson's correlation coefficient) in group U compared to the other two groups. We found a positive correlation between male gender and termination of motor block (P = 0.0487, Pearson's correlation coefficient) in group N compared to the other two groups. Conclusion: In our study, patients received satisfactory analgesia in the postoperative period regardless of technique used, age, gender, or potentially uncommon anthropometry.

In our study, patients received satisfactory analgesia in the post-operational period no matter what technique was used regardless of their age, gender or potentially uncommon anthropometry.