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Three Part Question

In [adult patients presenting to the emergency department with renal colic] does [Erector spine plane block]provide [effective analgesia]?

Clinical Scenario

A 33-year-old patient presents to the emergency department with right-sided flank pain and haematuria. The pain is described initially as 10/10 in severity. CT imaging demonstrates a 4mm non-obstructive stone in the right ureter. Despite intravenous ketorolac and morphine, the pain remains 9/10 in severity. The patient is otherwise well, and you wonder if an erector spinae plane block (ESPB) would be an effective alternative for analgesia.

Search Strategy

MEDLINE and EMBASE databases 1946 to September 2024 were searched with no date filters using the OVID interface and a broad keyword search strategy. The search strategy was as follows:

[renal colic.mp. or exp *Renal colic/ OR renal calculi.mp. or exp *Kidney Calculi/ OR ureteric colic.mp. or exp *Ureteral Calculi/ OR nephrolithiasis.mp. or exp *Nephrolithiasis/ OR urolithiasis.mp. or exp *Urinary Calculi/ or exp *Urolithiasis/ OR bladder stone.mp. or exp *Urinary Bladder Calculi/]
AND
[erector spinae plane block.mp. OR nerve block.mp. or exp *Nerve Block/ OR block.mp. OR regional block.mp.]

All papers identified as relevant from the OVID search were entered into Google Scholar's ‘Cited By’ function to screen for further relevant literature. The references of relevant papers were screened. Finally, a supplementary search using PubMed Medical Subject Headings (MeSH) terms was undertaken using the following formulae:

("Renal Colic"[Mesh]) AND ("nerve block"[Mesh])
("Renal Colic"[Mesh]) AND ("Analgesia"[Mesh])

Search Outcome

Our database search returned 464 results after limiting to human studies in the English language and removal of duplicate records by the OVID interface. Titles and abstracts were assessed independently by both authors. MK selected five papers for full text review and AB selected seven (unweighted kappa = 0.83, SE 0.12, 95% CI 0.60 to 1.00).

Both authors selected the same final four full texts to be included in this review. Two randomised controlled trials (RCTs) and two case series were included. The findings are summarised in Table

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Aydin ME et al 2021 Turkey	All renal colic presenting to ED n=40 Mean age: 38.88 ± 12.67 Male: 62.50% Intervention group (n=20) received ESPB with 30ml 0.25% bupivacaine Control group (n=20) received intravenous 50mg dexketoprofen trometamol	Prospective randomized clinical trial	Visual analogue scale (VAS) for pain (0-100mm) at baseline, 5, 15, 30, 45 and 60 minutes	In ESPB group VAS scores were significantly lower at all time points after intervention (P<0.001).	No blinding used. Limited evaluation of long-term analgesia in both intervention and control groups. Short assessment period of sixty minutes post-ESPB. Sample size may be insufficient for detection of adverse events associated with ESPB.
			Whether further analgesia (1mg/kg fentanyl was required post intervention. Given is VAS greater than or equal 40 after intervention	Control (NSAID) - Initial: 96.25 ± 6.15 - 30th minute: 36.05 ± 30.90 - 60th minute: 21.65 ± 22.17 Case (ESPB) - Initial: 98.60 ± 3.03 - 30th minute: 3.80 ± 8.78 - 60th minute: 1.50 ± 3.66
			Patient satisfaction (scale of 1-5).	Patient satisfaction higher in ESPB group (p<0.001). Further analgesia required less frequently in ESPB group (p<0.001).
Mehdi Torabi et al 2023 Iran	Refectory* renal colic presenting to ED. n=40 Mean age 36.48 Male 65% intervention group (n=20) received ESPB with 1% lidnocaine 4.5mg/kg at T8 level	Prospective randomized control trial	Numeric rating scale for pain (0-10) before intervention, 30 and 60 minutes post intervention Comparison of NRS between timepoint 1 and 2, 2 and 3, and 1 and 3. Patient satisfaction (standard Iowa questionnaire).	ESPB significantly lower NRS levels (p<0.01) at 30th minute and 60th minute Both groups had significant difference in NRS between at time points 1 and 2, 2 and 3, and 1 and 3. Control (IV fentanyl): - Initial: 8.55±1.27 - 30th minute: 3.25±1.60 - 60th minute: 4.55±0.88 Case (ESPB): - Initial: 8.60±1.09 - 30th minute: 1.30±1.03 - 60th minute: 2.20±0.83 Patient satisfaction showed no significant difference (p=0.69).	Trial states used single blinding but no explanation of what this involved Limited evaluation of long term analgesia in both intervention and control groups . Short assessment period of 60 minutes post ESPB Sample size may be insufficient for detection of adverse events associated with ESPB Insufficient information provided on route of administration of Ketorolac, total for and dosing regimen for fentanyl
Aydin ME et al 2019 Turkey	All renal colic presenting to ED n=3 Mean age 52.63 Male 33.33% Intervention (n=3), ESPB conducted at T8 or T9 level Cases 1 +2 received 30ml mix of 0.25 bupivacaine and 2% lidoicaine Case 3 received only 20mls	Case series	Visual analogue scale (0-10) performed before and following ESPB. Time until further analgesia required.	Mean baseline VAS was 9.33. After ESPB, mean VAS was 1.33. Further analgesia requirement time mean 9.67 hrs (8-11 hours).	Case series methodology with no comparator group. Varied dosing of anaesthetic agent and non-systematic collection of outcome and adverse event data.
Mark Noble 2022 USA	All renal colic presenting to ED n=10** Mean age: 51.60± 16.02 Male: 80.0% Mean age [7 cases with pre/post scores] :48.29± 12.12 **only 7 cases had pre and post block pain scores Intervention (n=10) ESPB performed at T7 level with [20-30ml pre-mixed solution of ropivacaine 123 mg, epinephrine 0.25 mg, clonidine 0.04 mg, and ketorolac 15 mg in 50 mL 0.9% normal saline solution]	Case series	Pain rated out of 10 performed before and following ESPB* *pre and post block pain scores recorded in only 7/10 cases	Mean baseline pain 7.85. After ESPB mean pain score of 0.71 (if multiple time points given, 30 minutes used).	Case series methodology with no comparator group. Varied dosing of anaesthetic agent and non-systematic collection of outcome and adverse event data. Lack of continuity in monitoring of pain score between cases studied as only seven out of ten cases had pre and post pain scores included.

Comment(s)

RCT evidence demonstrates that ESPB provides effective analgesia in renal colic for initial treatment (Aydin et al. 2021) and refractory pain (Torabi et al. 2023). However, we must interpret these findings carefully. Firstly, there was marked protocol variation between trials. Aydin et al. (2021) compared ESPB to intravenous dexketoprofen, a non-steroidal anti-inflammatory drug (NSAID) which is not commonly used in the UK. Torabi et al. used intravenous fentanyl. Both studies administered the block at T8 level, but used different anaesthetic agents: 75mg of 0.25% bupivacaine (Aydin et al., 2021) and 4.5mg/kg of 1% lidocaine (Torabi et al., 2023). Use of different control agents challenges generalisation of findings to different centres but does, at least, support the effectiveness of ESPB in a variety of circumstances. A further abstract was returned in the search supporting the evidence here, with ESPB leading to 100% reduction in pain in renal colic using the visual analogue scale at 30 minutes (Bubic & Oswald, 2021). Further details were not provided. Furthermore, both trials were limited in their use of blinding. Aydin et al (2021) did not attempt blinding and Torabi et al stated use of single blinding but did not provide any methodology of this. Challenges arise when blinding procedures associated with risk, but it is not impossible. Ramesh et al (2024) trialled ESPB for rib fractures and used ‘sham blocks’ (involving blunt needles) as a comparator. Using a similar sham block would provide better evidence to support ESPB for renal colic. The resource implications of ESPB are not explored in the included studies. This is problematic, as compared to standard analgesia, ESPB is likely to be more time- and equipment-intensive. Aydin et al. (2021) state that ESPB takes less than five minutes to complete but this was not measured. We expect more than five minutes would be required to find equipment, set up and complete the procedure in many centres. Similarly, only Aydin et al. (2021) assessed use of rescue analgesia (see Table 1) and neither trial measured duration of pain relief. Longer term outcomes would be of interest given that Torabi et al. (2023) report pain scores increase after at the 60th minute. Finally, in our search it became clear that ESPB is not the only block used to manage pain from renal colic. Other blocks mentioned included (but were not limited to) thoracic paravertebral (Finneran et al. 2020) and transversus abdominis (Kadioglu et al. 2020). There does not appear to be a study comparing types of blocks. We believe that further research would determine how and when ESPB is best used. Trials including a standardised block, blinding and longer-term outcomes (e.g. duration of pain relief, rescue analgesia use) would evidence potential healthcare resource benefits of ESPB and its relevance to everyday practice.

Clinical Bottom Line

ESPB appears to be effective in both initial analgesia for renal colic and for pain refractory to NSAIDs and opioids. The healthcare resource implications of ESPB are currently unclear

References

1. Aydin ME, Tekin E, Ahiskalioglu EO et al. Erector spinae plane block vs non-steroidal anti-inflammatory drugs for severe renal colic pain: A pilot clinical feasibility study Internal Journal of clinical practice 2021 Mar;75(3):e13789. doi: 10.1111/ijcp.13789.
2. Mehdi Torabi,1 Javad Darijani,1 Moghaddameh Mirzaee,2 and Amin Honarmand1 Ultrasound-guided erector spine plane block (ESPB) utilization in managing refractory renal colic pain in the emergency department World Journal Emergency Medicine World J Emerg Med. 2023; 14(3): 231–234.
3. Aydin ME, Ahiskalioglu A, Tekin E, et al. Relief of Refractory renal colic in the emergency department; a novel indication for ultrasound guided erector spinae plane block American Journal Emergency Medicine 2019 Apr;37(4):794.e1-794.e3. doi: 10.1016/j.ajem.2018.12.042. Epub 2018 Dec 23.
4. mark Noble et al The erector Spinae Plane Block as Novel Therapy for Renal Colic: A case series Journal of Ultrasound Medicine 2023 Jan;42(1):233-237. doi: 10.1002/jum.15998. Epub 2022 Apr 28.