Erector spinae plane block for intractable, nonsurgical abdominal pain: a scoping review

Article information

Clin Exp Emerg Med. 2024;.ceem.23.171

Publication date (electronic) : 2024 March 15

doi : https://doi.org/10.15441/ceem.23.171

Ashley Meyer¹, Campbell Belisle Haley², Eisa Razzak³, Amanda Dos Santos², Kyle Dornhofer², Edmund Hsu², Soheil Saadat², John Christian Fox², Megan Guy^,2

¹University of California, Irvine, School of Medicine, Irvine, CA, USA

²Department of Emergency Medicine, University of California, Irvine, Orange, CA, USA

³Stritch School of Medicine, Loyola University Chicago, Maywood, IL, USA

Correspondence to: Megan Guy Department of Emergency Medicine, University of California, Irvine, 3800 W Chapman Ave, Suite 3200 Orange, CA 92868, USA Email: guym@hs.uci.edu

Received 2023 December 3; Revised 2024 February 22; Accepted 2024 February 24.

Abstract

INTRODUCTION

Abdominal pain is a common presenting chief complaint in the emergency department (ED) and accounts for approximately 5% to 10% of annual ED visits [1]. The ongoing opioid epidemic and serious adverse events related to opioids create additional challenges for physicians when managing both acute and chronic abdominal pain. In recent years, regional anesthesia approaches such as celiac plexus nerve block have been used to manage visceral components of chronic, functional abdominal pain [2]. Erector spinae plane block (ESPB) is an ultrasound-guided nerve block that was introduced in 2016 and shows promise in treating visceral pain as well as somatic abdominal pain [3]. Using an ultrasound probe in the cephalocaudal orientation approximately 3 cm from midline, local anesthetic is injected into the erector spinae facial place which lies between the erector spinae muscles and the posterior surface of the transverse process. (Fig. 1) [4]. Analgesia is achieved with long-acting regional anesthetic injected into the erector spinae fascial plane, either as a bolus or a continuous infusion [5]. Nerve blocks including ESPB are favored due to their efficacy and limited adverse effects compared to pharmacologic agents [5]. The mainstream use of ultrasound to guide the procedure makes ESPB one of the safest peripheral nerve blocks. Despite the increasing popularity of ESPB, its role in the management of intractable, nonsurgical abdominal pain has not yet been fully characterized.

Fig. 1.

Insertion site and ultrasound view. (A) The transducer is oriented cephalocaudal and held over the transverse process. The needle insertion may be 1 to 2 cm from the probe. (B) Ultrasound view demonstrating the needle path contacting the posterior surface of the transverse process.

This scoping review aims to provide a better understanding of the safety and efficacy of ESPB in the management of patients experiencing intractable, nonsurgical abdominal pain. We chose to perform a scoping review due to limited prospective, randomized studies on this nerve block. This review includes all studies related to the use of ESPB for intractable, nonsurgical abdominal pain.

METHODS

PubMed and Scopus were queried to evaluate existing literature on ESPB for intractable, nonsurgical abdominal pain. We followed the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) checklist (Supplementary Material 1) [6].

Eligibility criteria

Articles of all study types published in English prior to July 1, 2023, were considered for inclusion. We included studies evaluating the use of ESPB to manage intractable, nonsurgical abdominal pain in adult patients and excluded studies pertaining to perioperative pain. These indications included but were not limited to pancreatitis, renal colic, herpetic pain, and functional abdominal pain. We defined “intractable” pain as pain that was refractory to at least one dose of oral or intravenous systemic pain medications.

We initially identified 30 published articles using the following search query: (TITLE-ABS-KEY ("erector spinae")) AND (TITLE-ABS-KEY ("plane block" or "nerve block")) AND (TITLE-ABS-KEY ("abdominal pain")).

Two reviewers (AM and CBH) independently screened a total of 30 titles and abstracts that met our predefined inclusion and exclusion criteria. Discrepancies between the reviewers were resolved by a third reviewer (SS). Following our initial screening, 35 articles underwent full-text review. We screened the references of all studies meeting our criteria to find additional studies. A total of 14 studies were ultimately included in this review (Fig. 2). Key aspects of each study are summarized in Table 1 [7–20].

Fig. 2.

Flowchart of search strategy for studies that used erector spinae plane block (ESPB) to treat nonsurgical abdominal pain.

Table 1.

Summary of published studies discussing the use of ESPB in intractable, nonsurgical abdominal pain

RESULTS

A total of 14 journal articles from eight countries between 2018–2023 were selected for scoping review based on their use of ESPB to treat intractable, nonsurgical abdominal pain (Table 1) [7–20]. There were 12 case-based studies, one systematic review, and one narrative review of ESPB for the treatment of intractable, nonsurgical abdominal pain. Of these 14 studies, eight took place in the ED, three involved patients evaluated by an inpatient pain service, two were from outpatient pain clinics, and one study combined multiple settings. There were 181 total described nerve blocks in the studies related to intractable, nonsurgical abdominal pain. No complications were reported in any of these studies.

Both single ESPBs and continuous nerve catheters were described in the included articles, with injections performed at the level T6–T11 thoracic spine levels. Medications used included single anesthetics as well as combinations of long-acting local anesthetics such as bupivacaine, ropivacaine, and levobupivacaine, while others used short-acting agents like lidocaine, corticosteroids, and normal saline for hydrodissection. Bupivicaine was the most frequently used local anesthetic and was often used in conjunction with lidocaine for immediate effect. Ropivacaine and lidocaine were also used alone to achieve analgesia. All studies using lidocaine injected it either as a mixture with a long-acting anesthetic or as a bolus before continuous infusion of a long-acting anesthetic [7–10].

There were 85 cases described in 14 articles that used ESPB for intractable, nonsurgical abdominal pain that was not a result of trauma or burns (Table 1) [7–20]. All the cases described using ESPB to treat abdominal pain refractory to at least one dose of oral or intravenous pain medications (our definition of “intractable” in this study). Six total cases described using ¬ESPB bilaterally to successfully treat refractory cancer-related pain due to colorectal cancer or cholangiocarcinoma [10–13]. Four studies described using ESPB for acute pancreatitis (10 total cases), while another study used ESPB for pain relief in a case of necrotizing pancreatitis [9,14–16]. To summarize, pain control was achieved in 11 pancreatitis cases using ESPB [9,14–17].

One case series of three patients described the successful use of ESPB followed by continuous infusion of 0.187% ropivacaine to treat functional abdominal pain in an outpatient pain clinic, with total resolution of pain at the 6-month follow-up reported for two patients [8]. Two case studies reported the use of ESPB to treat pain from postherpetic neuralgia, with one block performed at the tenth thoracic spine level for abdominal pain and another block used for cervicothoracic and shoulder pain [8,18]. Two prospective studies of ESPB for postherpetic neuralgia were also found: one observational study including 34 patients and one randomized controlled trial with 50 patients (26 randomized to the treatment group) [13]. One case series in the ED used ESPB for renal colic, with an improvement in pain score by an average of 8, using the average visual analog score; furthermore, additional pain medications were not required following these blocks for 8 to 11 hours [7]. A case report demonstrated the usefulness of ESPB in treating abdominal pain from mesenteric ischemia with improvement in pain from 2 out of 3 to 0 out of 3 [19].

This review identified multiple methods of achieving ESPB; injectable anesthetics were combined with corticosteroids in some instances while continuous regional anesthetic infusion was used in others. This resulted in a wide variation in the duration of analgesia. Continuous infusions led to decreased analgesic requirements that lasted throughout catheter placement and in some instances pain relief lasting up to 12 weeks [8,13]. However, continuous infusions were largely performed by inpatient or outpatient pain services [8,9,14,18,19]. In the ED studies (eight total), single blocks were used and demonstrated variable duration. Application of ESPB to treat the pain associated with renal colic resulted in no further oral or intravenous analgesic requirements for 8 to 11 hours [7,20]. A case report of ESPB for pancreatitis reported 24 hours of pain relief, while another described 19 hours of analgesia [15,16]. A case series of ESPB in patients with pancreatitis reported that the median time until the next oral or intravenous analgesic was required was 9 hours [10]. One study performed ESPB using ropivacaine and methylprednisolone for cancer-related pain and reported an improvement in pain score using the numerical rating scale for more than 2 weeks [12].

DISCUSSION

Review of the literature revealed that ESPB is effective for the treatment of intractable, nonsurgical abdominal pain. While this procedure has clear benefits, there are several concerns that need to be addressed prior to widespread use of ESPB in the ED setting. 

Unlike many other forms of pain relief, ESPB offers multidermatomal analgesia to the thoracic and abdominal walls anteriorly, posteriorly, and laterally [21]. This is achieved by the analgesic spreading along fascial planes throughout multiple vertebral levels, effectively anesthetizing a large area. ESPB provides a targeted approach to administering analgesia, effectively treating both somatic and visceral pain without the systemic side effects seen with oral or intravenous pain medications.

ESPB can serve as an opioid-sparing alternative to improve abdominal pain, including cancer-related pain [22]. Similarly, for chronic noncancer pain, evidence suggests that while opioids significantly improve pain, the magnitude of such improvement is small [23]. ESPB can be used to address this discrepancy. Moreover, while opioids may reduce pain, they may also have numerous adverse effects including nausea, vomiting, constipation, hyperalgesia, bradycardia, dizziness, syncope, delirium, and dependence [23,24]. Through our literature search, we identified numerous studies of patients on high doses of opioids who were able to reduce their opioid dosage after receiving ESPB.

ESPB and other regional nerve blocks also facilitate avoidance of nonopioid medication-related adverse effects. Common effects of nonsteroidal anti-inflammatory drugs include renal injury, gastritis/peptic ulcer disease, and gastrointestinal bleeding [25].  Additionally, muscle relaxants and neuropathic pain medications such as anticonvulsants and antidepressants can cause dizziness, drowsiness, and somnolence [26,27]. These systemic side effects are especially important to consider in the elderly who are most at risk for these adverse medication reactions. Using ESPB in the elderly for the treatment of abdominal pain could be an effective and safe alternative to systemic pain medications.

Finally, ESPB has been performed in multiple EDs in different countries, in addition to inpatient pain services and pain clinics. ESPB appears to be safe and effective when used by emergency physicians. With ubiquitous access to ultrasound machines and increasing emergency physician proficiency in ultrasound-guided procedures, there is significant potential for expanding the use of this regional nerve block in the ED.

While ESPB has broad utility, some adjustments to the ED workflow may be required for the block to be feasible. Nerve block kits that contain the equipment necessary for the procedure such as the local anesthetic, nerve block needle, syringe, extension tubing, sterile gel, ultrasound probe cover, and ChloraPrep will help facilitate the procedure for busy emergency physicians. The time to pain control may be delayed by the time it takes to obtain consent and prepare for the procedure; therefore, decreasing the time required to acquire the materials is important. Additionally, physicians without adequate point-of-care-ultrasound training may be hesitant to conduct regional nerve blocks; this could be mitigated by departmental training. It would be beneficial for emergency medicine residents and attendings to receive training on performing ESPB under ultrasound guidance to increase physician comfortability performing the block. Finally, many of the studies described continuous infusions via nerve catheters by pain specialists, which is not feasible in the emergency setting. Thus, while ESPB may be useful for short-term pain relief of up to 24 hours, additional pain management may be required after the anesthetic wears off, and appropriate follow-up is necessary.

Despite the various benefits of ESPB, there are several risks that require consideration. While this is rare under ultrasound guidance, it is possible to cause a pneumothorax while performing this nerve block, although there were no reported pneumothoraces in any of the reviewed studies. A pneumothorax may occur as the result of poor hand-eye coordination or miscalculation of the proper injection site if the provider loses visualization of the needle tip under ultrasound guidance [28]. Additionally, as with any injection, there is the risk of infection if sterility is broken, and a risk of bleeding if the provider penetrates a blood vessel or if the patient is prone to bleeding. Furthermore, while there are theoretical complications such as local anesthetic systemic toxicity and neurovascular injury, these are extremely rare and none of these complications were reported in the studies we reviewed.

While the effectiveness and safety of ESPB have been demonstrated, the time required to perform the procedure may decrease provider willingness, and the pain associated with receiving an injection may decrease patient willingness. Additionally, depending on the ED length of stay, a patient may require multiple nerve blocks once the anesthetic wears off, which can be time-consuming for both the physician and the patient. While the overall benefits of EPSB may outweigh these negative aspects, patient and provider preferences and treatment goals should be taken into consideration.

An important limitation of this scoping review is the lack of data and randomized controlled trials on ESPB. Over a 5-year period, 14 journal articles were found that met the inclusion criteria. As such, our findings suggest several potential uses of this nerve block but there is not a large body of evidence to support these uses. Prospective studies are needed to provide further evidence supporting the feasibility and safety of ESPB. Additionally, given that our criteria involved only articles published in English, there is the possibility that we missed supporting evidence from non-English articles; this limitation should be addressed in future studies. 

In summary, the current literature illustrates the potential benefits of ESPB in patients experiencing intractable, nonsurgical abdominal pain. Additional research will enhance our understanding of the advantages and limitations of ESPB. Based on the current literature, ESPB is a promising alternative to standard systemic pain medications for emergency physicians and can reduce the incidence of systemic side effects from pain medications, especially in at-risk populations such as the elderly. More studies are needed to unequivocally demonstrate that this regional nerve block is both feasible and cost-effective in the ED setting. To conclude, the current literature supports ESPB as a safe, effective analgesic approach for intractable, nonsurgical abdominal pain of multiple etiologies. However, our review highlights the need for prospective, randomized controlled trials of ESPB.

Supplementary Material

Article information Continued

Notes