Introduction
The use of peripheral nerve blocks (PNBs) for orthopedic surgery has seen significant growth in recent years due to its advantages such as intraoperative and post-operative analgesia and increased safety when combined with ultrasound-guided regional anesthesia (UGRA) or neurostimulation1.
Only 13.3% of patients undergoing joint arthroplasty (shoulder, hip, or knee) receive a PNBs. UGRA was used in only 10% of shoulder cases, 3% of hip cases, and 5% of knee cases. However, the use of ultrasound in regional anesthesia (RA) for these three procedures has increased over time from 0% to 21%, 0.2-4.7%, and 0.3-9.5%, respectively2.
In orthopedic surgery, RA is a valuable tool due to the prolonged analgesia it provides, which can be extended using catheters. Although catheters may carry the risk of puncture site infections, unintended pinching or bending can usually be easily resolved3.
A prospective randomized study in shoulder surgery compared three approaches for brachial plexus block (supraclavicular, infraclavicular, and axillary) guided by ultrasound using 40 mL of 1% lidocaine. The study found Horner’s syndrome as the only complication in 8% of patients in the supraclavicular technique group, while no complications were reported in the other groups4.
Reported serious complications include pneumothorax, temporary hemidiaphragmatic paresis with dyspnea and elevated hemidiaphragm, accidental vascular puncture, local anesthetic toxicity, and prolonged neurological deficit due to nerve damage4.
Techniques for the upper extremity
INTERSCALENE BLOCK (IEB)
An IEB and supraclavicular block (SCB) are alternative techniques for obtaining adequate analgesia and anesthesia during shoulder surgery. Both procedures have been compared in several meta-analyses, which have shown their effectiveness and low incidence of complications5,6.
IEB can be efficiently performed using ultrasound or a neurostimulator, but it is important to note that the target structures being blocked are closer to the lung, spine, and spinal cord, despite being farther from the lung apex7. The safety of the use of UGRA in IEB has been studied and has shown good results, including perioperative analgesia5. However, close clinical monitoring and patient surveillance is still recommended due to a higher incidence of ipsilateral hemidiaphragmatic paresis associated with the technique7.
SCB
SCB is a commonly used and effective procedure in shoulder surgery due to its ability to provide good transoperative and post-operative analgesia and anesthesia, as well as its low incidence of complications, such as dysphonia7. When compared to IEB, SCB provides equally effective postoperative analgesia, but with a lower incidence of phrenic nerve block (PHDI) compared to IEB. The use of ultrasound during SCB also results in a low incidence of pneumothorax6.
Techniques for the lower extremity
ADDUCTOR CANAL BLOCK (ACB)
The saphenous nerve, which supplies cutaneous sensation to the peripatellar region and the medial aspect of the limb below the knee, separates from the femoral nerve in the proximal third of the thigh8. Therefore, the ACB significantly reduces pain during arthroscopic meniscectomy9. ACB is also useful and effective in total knee arthroplasty, which is often performed in elderly patients with a high prevalence of comorbidities and therefore a higher risk of intraoperative and post-operative events associated with general anesthesia.
To perform ACB, the medial thigh of the limb to be blocked must be cleaned, and then the ultrasound transducer must be placed horizontally in the middle third of the anteromedial thigh. The apex of the femoral triangle is traced to locate the adductor hiatus, which contains the femoral artery and vein, the saphenous nerve, the vastus medialis nerve, two fascicular branches of the femoral nerve, and the articular contribution of the obturator nerve10. The needle should be inserted flat and be visible in its entirety. Once the tip is in the canal, the local anesthetic is administered with or without adjuvants after aspiration to avoid intravascular infusion.
ACB has several advantages, including the ability to be performed preoperatively and to be combined with other techniques, such as spinal block, shorter surgical time, and shorter ischemia time10. In addition, ACB offers better analgesia for knee procedures as the block includes the saphenous nerve, vastus medialis nerve, and potentially the articular contribution of the obturator nerve to the knee11,12. One way to perform ACB is to place the patient in the supine position with slight external rotation of the pelvic limb to be blocked. The ultrasound is placed in the anteromedial section of the thigh, starting in the middle third. The superficial femoral artery is located, and then the flow is directed to identify the vastus medialis, adductor longus, and adductor magnus.
FEMORAL NERVE BLOCK (FNB)
FNB turns out to be another alternative to CAB which, as already mentioned, is advantageous in patients with risk factors for transoperative events associated with general anesthesia.
One of the most widely used techniques for BNF using a neurostimulator begins with placing the patient in the supine position, locating the femoral artery below the inguinal ligament, inserting the lateral needle into the femoral artery through the iliopsoas muscle, confirming the correct site with the neurostimulator and the local anesthetic is administered13.
When BNF is associated with intra-articular infiltration, it results in high intraoperative analgesia, anesthesia, and opioid savings13. In another study, analgesia in patients with spinal block was compared using the verbal numerical scale between continuous BNF with catheter versus epidural block (BPD) with catheter where it was found that in the first 6 h the BPD was superior in pain control, but at 24 h the pain control was the same while the prevalence of side effects was significantly lower in the BNF group14.
Methods
Study selection and quality assessment
We searched MEDLINE from 1990 to November 2020 for trials and reports of prospective observational studies of patients undergoing ultrasound-guided brachial plexus nerve block (BNP) for elective orthopedic surgery, and reporting the rate of complications associated with the regional anesthetic technique. The search was conducted in English and Spanish, using medical search terms such as “UGRA,” “elective orthopedic surgery,” “complication,” “morbidity,” “mortality,” and “safety.” The reports were independently reviewed by two researchers, Mario Sánchez and Ulises Sánchez.
The selected studies met the following criteria: (1) they were prospective, (2) they used UGRA, (3) the surgery was an elective orthopedic procedure, and (4) the total rate of complications related to RA was reported. Studies with insufficient information or that did not report the total rate of complications were excluded, as were retrospective studies and case reports. The quality of the accepted reports was assessed using four a priori criteria for quality: (1) blinding, (2) consecutive patient recruitment, (3) individual (versus composite) accepted standards, and (4) non-selective use of accepted standards. Each criterion was awarded one point, with a maximum possible score of 4.
Data extraction
The type of BNP for elective orthopedic surgery, UGRA, and rate of complications associated with RA were collected. The type of elective orthopedic procedure, ultrasound-guided regional anesthetic technique, and the report of any complications directly attributed to the anesthetic technique or death were also extracted. Complications were analyzed based on the regional anesthetic technique used.
PNBs in the thoracic limb
A total of 22 articles on BNP in thoracic limb surgery were identified that met the criteria mentioned above. These articles were grouped by type of surgery, resulting in: 6 articles about BNP in unspecified thoracic limb surgery, 8 articles about BNP in shoulder surgery (including 2 about exclusive rotator cuff surgery), 1 article about BNP in elbow surgery, 3 articles on BNP in distal thoracic limb surgery, 2 articles on BNP in forearm surgery, and 2 articles on BNP in hand surgery.
Unspecified thoracic limb surgery
The risk of pneumothorax in periclavicular BNP (supraclavicular and infraclavicular) without the use of ultrasound has been reported to be up to 6.1%, while with the use of ultrasound, it can be reduced to 0.06%15. The use of ultrasound also results in a higher quality of the block compared to the traditional technique using anatomical references16. Adjuvants, such as dexamethasone at a recommended dose of 4 mg, can be used to prolong the duration of BNP in the thoracic limb17. The use of ultrasound for BNP is also less uncomfortable than the use of neurostimulation, as seen in the case of the axillary nerve18.
Adding adjuvant blocks (distal median, radial, and ulnar nerve blocks) when performing a BNP has been proposed to accelerate the onset of anesthetic effects compared to BNP alone19. When performing an infraclavicular block, a retroclavicular approach is recommended for better visibility of the needle to administer the drugs20.
Shoulder surgery
The incidence of hemidiaphragmatic paresis during continuous EIB can be reduced by positioning the tip of the extrafascial catheter without affecting the quality of the block21. The duration of analgesia for shoulder surgery is similar for both EIB and BSC22. The use of ultrasound results in a faster onset of anesthesia compared to the use of neurostimulation for EIB23. The incidence of phrenic nerve paresis is not affected by the EIB approach24. The extrafascial administration of drugs during EIB is associated with a lower incidence of phrenic nerve paresis25. No relationship has been found between the volume administered, between 20 and 10 mL, and phrenic nerve paresis in EIB26, although there seems to be a relationship when the comparison is made between 10 mL and 5 mL27. Continuous EIB has been shown to have fewer side effects but also lower analgesic efficacy compared to fluoroscopy-guided continuous cervical epidural block28.
Elbow surgery
Both EIB and BSC for shoulder surgery are equally effective, although BSC results in a higher incidence of thoracic limb paresthesia29.
Distal thoracic limb surgery
There is no difference in terms of the duration of sensory block, post-operative analgesic effect, or duration of motor block in the shoulder when comparing axillary nerve block to distal PNBs30. The quality and efficacy of BSC is higher when using ultrasound instead of a neurostimulator31. A greater sensory block is achieved using a single injection in EIB compared to the double injection technique for the axillary nerve (posteromedial to the axillary artery and into the musculocutaneous nerve)32.
Forearm surgery
Sensory blockade in BSC can be prolonged without increasing complications by adding dexamethasone 8mg as a pharmacological adjuvant33. Hematoma block for pre-operative, transoperative, and post-operative analgesia management in distal radius fractures is just as effective as using midazolam and intravenous fentanyl34.
Hand surgery
Using ultrasound during continuous infraclavicular block of the brachial plexus results in greater block success and better block prediction35. The minimum concentration of bupivacaine (using a 5 mL volume) needed to achieve successful axillary brachial plexus block is 0.241%36.
Pelvic limb
A total of 15 articles were identified for BNP of the pelvic limb using the previously mentioned criteria. Four clinical trials were found for hip surgery37–40, two clinical trials for knee surgery14,41, one clinical trial for hip surgery, ankle42, two clinical trials for foot surgery43,44, and six clinical trials where the type of orthopedic surgery was not defined, but focused on the distal tibial region, foot, or ankle45–50.
Hip surgery
The following anesthetic techniques were found: ultrasound-guided regional (FNB,38,39) 3-in-1 block, lumbar plexus block, psoas compartment block38, and fascia iliac compartment block37,38,40.
The most effective regional technique for hip surgery is considered to be the lumbar plexus block38,51, but it is difficult to perform and may result in residual motor block38,51. Hence, the FNB (BNP) is considered the easiest, safest, and most effective38,39. When performed with distal pressure and a large volume of local anesthetic, the FNB is called a 3-in-1 block38. It results in better lateral and medial distribution and better analgesic results since femoral, lateral cutaneous, and possibly obturator nerve blocks occur38.
The fascia iliac compartment block is another new, successful, and safe technique, especially in older adults with hip fracture37,40. In addition, local infiltration with local anesthetic, ketorolac, and adrenaline, carried out by the surgeon, seems to be a simple and good alternative38.
RA has proven benefits in this type of surgery, such as less pain intensity and greater mobilization at 24 h, fewer hospital stays, less incidence of post-operative delirium, and lower opioid consumption and its adverse effects (nausea, vomiting, or pruritus)37–39. The only reported associated complication was paresthesia in the pelvic limbs (50% incidence), but 77% complete sensory recovery was observed at 24 h37–39. No significant secondary adverse effects were found for the fascia iliaca block40.
Knee surgery
For total knee arthroplasty, ultrasound-guided femoral block (BNP) was used with a success rate of 90-95%14. The reported complications were paresthesia (3%) and urinary retention (10%), both of which resolved early14.
For arthroscopic knee medial meniscus repair, saphenous nerve block in the adductor canal (BNP) resulted in a lower incidence of postoperative pain at rest, in recovery, and at 24 h, as well as lower opioid consumption41. No significant adverse effects were found41.
Ankle surgery
The BNP used for ankle surgery was the proximal popliteal sciatic nerve and saphenous nerve block. Benefits included superior safety compared to other anesthetic techniques and better post-operative pain control. No associated complications were found42.
Foot surgery
Regional ultrasound techniques used for foot surgery included BNP of the ankle (superficial and deep peroneal, posterior tibial, and saphenous nerves)43 and blockade of the popliteal sciatic nerve both proximal and distal to its bifurcation44. The benefits of RA include reduced use and adverse events of opioids, improved postoperative pain control, higher patient satisfaction, earlier mobilization, and shorter hospital stays. No complications were found associated with the block43,45. It is important to note that better results were found for distal sciatic nerve block (tibial and common peroneal nerve) in obese patients compared to the proximal approach44.
For unspecified pelvic limb (distal tibial, ankle, and foot)
The sciatic nerve BNP in the popliteal fossa is a commonly used block for below-knee surgery with no significant adverse effects45–50. The reported success rate for subparaneural or subfascial infiltration (at the beginning of the bifurcation) was 60-100%, and it showed a shorter latency, a 0% failure rate, and an increase in the duration of sensory blockade of the tibial nerve when compared with unintentional extraneural or intraneural infiltration45. Another article found that single subepineural infiltration into the sciatic nerve bifurcation provides a higher success rate, shorter time to perform the technique, and lower latency49. However, another study found similar results for both approaches47. In addition, better results were found when the ultrasound approach was performed in the long axis and “in-plane”48. It is recommended to evaluate the benefit of adding perineural dexamethasone to the sciatic, as additional benefits in the quality of surgical recovery have not been demonstrated50.
The BNP for thoracic or pelvic limb surgery requires a clear understanding of anatomy, as well as some skill in using the USG and knowledge of it. The disadvantages of performing these procedures are the lack of material and USG equipment, the lack of mastery of the technique, and some complications depending on the block. Despite these, we obtain better control of analgesia, timely rehabilitation, reduced consumption of opioids and NSAIDs.
Conclusions
The use of BNP was not widely adopted for some time, particularly in the private sector in Mexico, due to factors such as the time required to perform the block, its success rate, and potential complications. However, advances in technology, including the development of new USG and neurostimulators and the availability of clinical trials, meta-analyses, and guidelines, have made BNP a highly efficient and low-complication technique. As anesthesiologists, our goal is to provide the best possible pain management for our patients, and BNP has proven to be a viable option for many patients with comorbidities. In addition, BNP reduces the need for systemic administration of drugs, which can cause side effects and complications.
Conflicts of interest
The authors declare that they have no conflicts of interest.
Funding
The authors declare that they have not received funding for this study.
Ethical disclosures
Protection of human and animal subjects. The authors declare that no experiments were performed on humans or animals for this study.
Confidentiality of data. The authors declare that no patient data appear in this article.
Right to privacy and informed consent. The authors declare that no patient data appear in this article.
