Authors: Mark Winstanley, Andy Neill, Dave McCreary, Becky Maxwell, Chris Connolly, Michelle Tipping / Codes: ACCS LO 2, SLO1, UC7, UP1, UP5, UP6 / Published: 02/03/2021

Comparison of Intravenous Ketorolac at Three Doses for Treating Renal Colic in the Emergency Department: A Non-Inferiority Randomized Controlled Trial

Journal and Year

Academic Emergency Medicine. Dec 2020.

Lead Author

Lily Eidinejad


– We’ve looked at a paper before on [NewInEM in 2017], asking whether the analgesic ceiling for ketorolac is lower than our traditionally prescribed 30mg dose
– Ketorolac is a pretty potent NSAID and with that comes potential side effects including: nausea, vomiting, dyspepsia, platelet inhibition, GI bleeding, renal injury
– The adverse effects are usually dose dependent, so if we can use a lower dose, we probably should
– The previous study we reviewed looked at ketorolac for a multitude of pain syndromes, rather than the specific diagnosis for which we arguably use it the most, renal colic

Study Design

– Prospective, double blind, randomised clinical trial
– Non-inferiority

Patients Studied

– Adults with acute flank pain thought by clinician gestalt to be due to renal colic
– Excluding: a variety of things but basically people you wouldn’t give NSAIDs to
– Also patients who had received analgesia in the previous 24 hours


– IV ketorolac 10mg or 20mg


– IV ketorolac 30mg


– Primary: Pain reduction on VAS at 30 minutes post ketorolac administration
– Secondary:
– Pain reduction at 15, 45 and 60 minutes.
– Need for rescue analgesia at 30 minutes
– Adverse effects
– Non-inferiority limit: 15mm more than the mean pain score in the 30mg group
– Power calculation based on the renal colic group of Motov’s study – 55 per group needed

Summary of Results

– 165 patients (55 each subgroup)
– 30mg group: VAS 90 → 40mm
– 20mg group: VAS 80 → 40mm
– 10mg group: VAS 90 → 40mm

– 10 and 20mg not inferior to 30mg doses

– N&V most common adverse effect (all groups – most likely due to renal colic)
– Headache second most frequent – more common in 30mg group (18%) though not significantly

Authors Conclusion

In this study, ketorolac showed similar analgesia profile in doses of 10, 20 and 30mg in pain management of renal colic. Our results are consistent with the previous studies that proposed a lower dose of 10mg would be sufficient for pain control.

Clinical Bottom Line

If you aren’t already, I think it’s reasonable at this stage to say you should be using lower doses of ketorolac, particularly in the treatment of renal colic. 10mg is probably the analgesic ceiling for ketorolac. I often use 15mg just for ease of nursing dose measurement though – it really depends on what formulation of ketorolac you have.

Other #FOAMed Resources / References:

New in EM February 2017

This month Chris and Becky are looking at NICE guideline 185 on the treatment of ACS published at the end of 2020.

It’s a long guideline with quite a bit for the cardiologists around angio-intervention and rehab. We’ll not touch on this and as always try and pick out the bits relevant to us in EM in the UK. As always have a look and a read for yourself and pick out the bits relevant to your practice.

Early treatment of STEMI:

Key principles: Early recognition is important. Remember that a patient with chest pain should have an ECG within 15mins of arrival to ED.
We think that the skill of ECG interpretation is core in EM and constant considered practice should be part of all of our CPD!
(We like Steve Smith’s blog and this recent talk he did was great

Angiography and follow on PCI should be offered if the patient presents within 12 hours of onset of symptoms and PCI can be delivered within 2 hours of when you could give thrombolysis

Important point: If the person presents more than 12 hours after the onset of symptoms but the is ongoing evidence of ischaemia then consider PCI

This guideline has updated us with lots of combinations of antiplatelets especially in the context of NSTEMI and unstable angina. The visual summaries are probably the best way to interpret this all and a link is below!!

As always if there is any feedback or any guidelines you want us to cover then get in touch and let us know!



Andy Neill
Dave McCreary

Clinical question

– can we let people take some of the tetracain drops home with them when they present with corneal abrasions


– corneal abrasions are common, and are very painful. Tetracaine is one of those interventions in EM that you can see work in front of your eyes. It makes the patient feel better, it facilitates examination. It’s a win win. Then we send them home on some paracetamol and maybe an NSAID
– i was always taught – do not give people this stuff home with them as their eye balls will melt and the abrasion will never heal and you’ll get struck off the register and your wife will leave you and you’ll go bald and and your life will be over.
– the idea of take home tetracaine has been around for a while but like a lof of dogma in medicine it’s really hard to refute.


Short-Term Topical Tetracaine Is HighlyEfficacious for the Treatment of Pain Caused by Corneal Abrasions: A Double-Blind, Randomized Clinical Trial


Shipman, Annals EM 2020


– RCT double blind which we like
– done in a single academic ED in the states
– ED patients with abrasions
– no contact lens or infections, which seems sensible
– could get usual meds for exam and during ED stay but on going home they were randomised to tetracaine v placebo. Neither doc nor patient knew what they were getting
– reassessed 24-48 hrs by an EP blinded to intervention for a repeat slit lamp exam
– outcome was pain score at the 24-48 hr follow up
– powered to find a 1.5 point difference on the 10 point pain score which given the dramatic nature of the intervention seems very reasonable.


– pain score was 1 vs 8
– no difference in adverse outcomes (not that a study this small could tell that)
– note most (80%) didn’t have any residual abrasion at the follow up – suggesting they were probably the typical small ED abrasions we see.


– I find this quite compelling and a well done study. It is not the first, an NZ randomised trial by Waldman in 2014. It had similar numbers and was powered to look at safety and it was a +ve trial. Oddly they didn’t find a big difference in pain scores.
– i did this fairly commonly in the past 5 years – i would give patients a two or three of the little plastic ampoule thingies.
– i think to operationalise this though it needs a little policy behind it and in particular i think the 24-48 hr follow up was useful here. I think when implementing something like this that may be viewed by some as “risky” that being super conservative with follow up is a good idea