Chentao Gu

Regional anesthesia is a popular method for surgical anesthesia in clavicular surgery. Selective blocking of the cervical 3, 4, and 5 nerve roots shows promise in clavicle surgery, with its fast onset, good anesthesia and less complications, necessitating evaluation of its impact on diaphragmatic function. The purpose of this study is to examine the safety of C3, 4, and 5 nerve root block for its application in clavicle surgery. We conducted a pragmatic, randomized trial to evaluate the effect of C3, 4, and 5 nerve root block as compared with interscalene with intermediate cervical plexus block in diaphragmatic motion. This study involved forty patients undergoing right clavicle surgery. Patients were assigned in a 1:1 ratio to either a C345 nerve root block (administered with 2, 3, and 5 ml of 0.5% ropivacaine) or an interscalene with intermediate cervical plexus block (ISB + ICPB, each receiving 10 ml of 0.5% ropivacaine). Diaphragmatic kinetics were quantitatively assessed using sonographic techniques. The primary outcome was the incidence of complete hemi-diaphragmatic paralysis, observed at 30 min post-blockade. Secondary outcomes included the rate of complete hemi-diaphragmatic paralysis at 15 min and the degree of diaphragmatic motion restoration at 2, 4, 6, and 8 h post-blockade, onset time of block, motor block score in upper extremity, and adverse events. Results showed that only one patient (5%) in the C345 group vs. fifteen (75%) in the ISB + ICPB group experienced complete hemi-diaphragmatic paralysis at 30 min during deep breathing (P = 0.001). No patients in the C345 group, compared to five (25%) in the ISB + ICPB group exhibited paradoxical movement at 30 min during voluntary sniffing (P = 0.0471). Additionally, the C345 group demonstrated significantly greater diaphragmatic motion and upper limb strength restoration at all measured intervals post-blockade. Moreover, faster onset time and less adverse events were observed in the C345 group vs. in the ISB + ICPB group. Benefit from low volume of local anesthetics, the C345 nerve root block not only significantly reduces the incidence of complete hemi-diaphragmatic paralysis but also facilitates better recovery from diaphragmatic paralysis compared to the ISB + ICPB. It can be inferred that C345 is a more beneficial anesthesia method for early recovery of clavicular patients. Trial registration number: ChiCTR2300078283 04/12/2023.

Background: Variable innervation of the clavicle is a major challenge in surgery of clavicle fractures with patients under regional anesthesia. An interscalene block (ISB) combined with an intermediate cervical plexus block (ICPB) provides analgesia in clavicle fracture surgery, but this combination does not completely block sensation in the midshaft or medial clavicle. Cervical nerve root block is an alternative to deep cervical plexus block and has recently been used as an analgesic method in the neck and shoulder. Whether it should be used as an alternative for midshaft and medial clavicle fractures is unknown. Questions/purposes: In this randomized controlled trial, we compared a C3, 4, and 5 nerve root block to ISB combined with ICPB in surgery of midshaft and medial clavicle fractures in terms of the (1) proportion of patients achieving a sensory block that is sufficient for surgery, (2) onset time and duration of the block, and (3) effectiveness of postoperative analgesia, as measured by pain scores and consumption of analgesics. Methods: Between November 2021 and December 2021, we treated 154 patients for clavicle fractures. A total of 122 were potentially eligible, 91 of whom agreed to participate in this study. Twenty-nine patients were excluded because the patients chose general anesthesia or declined to undergo surgery. Ultimately, 62 patients were randomly allocated into the C3, 4, and 5 group or ISB + ICPB group, with 31 patients in each group; there were no dropouts. All patients were analyzed in the group they were randomized to under intention-to-treat principles. The assessor and patients were blinded to randomization throughout the trial. The two groups did not differ in any important ways, including age, gender, BMI, American Society of Anesthesiologists classification, and type of clavicle fracture. The two groups received either an ultrasound-guided C3, 4, and 5 nerve root block with 2, 3, and 5 mL of 0.5% ropivacaine or ultrasound-guided ISB with ICPB with 20 mL of 0.5% ropivacaine. The primary outcome was the proportion of patients in each group with a successful nerveba block who did not receive general anesthesia; this was defined as nerve block success. Secondary outcomes included the onset time and duration of the sensory block, defined as the onset to the moment when the patients felt pain and sought rescue analgesia; pain assessment in terms of the numeric rating scale (NRS) score (range 0 to 10) for pain after nerve block before and during surgery; and the median amount of sufentanil consumed intraoperatively and postoperatively in the recovery room. The dosing of sufentanil was determined by the assessor when the NRS score was 1 to 3 points. If the NRS score was more than 3 points, general anesthesia was administered as a rescue method. Complications after the two inventions such as toxic reaction, dyspnea, hoarseness, pneumothorax, and Horner syndrome were also recorded in this study. Results: A higher proportion of patients in the C3, 4, and 5 group had a successful nerve block than in the ISB + ICPB group (97% [30 of 31] versus 68% [21 of 31], risk ratio 6 [95% CI 1.5 to 37]; p < 0.01). The median onset time was 2.5 minutes (range 2.0 to 3.0 minutes) in the C3, 4, and 5 group and 12 minutes (range 9 to 16 minutes) in the ISB + ICPB group (difference of medians 10 minutes; p < 0.001). The sensory block duration was 10 ± 2 hours in the C3, 4, and 5 group and 8 ± 2 hours in the ISB + ICPB group (mean difference 2 hours [95% CI 1 to 3 hours]; p < 0.001). The median sufentanil consumption was lower in the C3, 4, 5 group than in the ISB + ICPB (median 5 µg [range 0.0 to 5.0 µg] versus median 0 µg [range 0.0 to 0.0 µg]; difference of medians 5.0 µg; p < 0.001). There were no differences between the two groups regarding NRS scores after nerve blocks and NRS score for incision and periosteum separation, with the minimum clinically important difference set at a 2-point difference (of 10). There were no severe complications in this study. Conclusion: Based on our analysis of the data, a C3, 4, and 5 nerve root block was better than ISB combined with ICPB for surgery to treat medial shaft and medial clavicle fractures. When choosing the anesthesia method, however, the patient’s basic physiologic condition and possible complications should be considered. Level of Evidence: Level I, therapeutic study.