Background

Renal colic is a commonly encountered diagnosis in the emergency department that is known to cause significant pain. In clinical practice, the initial goal is prompt pain management while simultaneously working to confirm the suspected diagnosis. Because of the severity and acuity of the pain associated with renal colic, opioid pain management has often been used. Given the overall goal of reducing the use of opioid pain medications, emergency physicians have been working to identify alternative pain management strategies with agents such ketorolac and lidocaine. In this journal club, we examine the evidence in support of these treatment strategies.

Articles reviewed

1. Eidinejad L. et al. Comparison of intravenous ketorolac at three doses for treating renal colic in the emergency department: A noninferiority randomized controlled trial. Acad Emerg Med. 2020 Dec 28.[Pubmed]

2. Motov S. et al. Comparison of intravenous lidocaine/ketorolac combination to either analgesic alone for suspected renal colic pain in the ED. American Journal of Emergency Medicine. 2020 Feb; 38 (2): 165-172.[Pubmed]

3. Safdar B. et al. Intravenous morphine plus ketorolac is superior to either drug alone for treatment of acute renal colic. Ann Emerg Med. 2006 Aug; 48(2): 173-81.[Pubmed]

Additional reading

4. Berger, et al. Racial disparities in analgesic use amongst patients presenting to the emergency department for kidney stones in the United State. American Journal of Emergency Medicine 39 (2021) 71-74.[Pubmed]

EIDINEJAD ET AL

This is a prospective randomized, double-blind trial examining 3 different doses of IV ketorolac for the management of pain related to renal colic. The primary endpoint was pain reduction at 30 minutes with secondary outcomes looking at 15, 45, and 60 minute scores as well as need for rescue analgesia and adverse effects. Adult patients presenting with renal colic were enrolled across 3 hospitals in Tehran and were excluded for age > 65, PUD, GI bleed, renal insufficiency as well as those who had received analgesics within 24 hours. 165 patients were divided into 3 equal groups and received wither 10 mg, 20 mg, or 30 mg of IV ketorolac. All 3 groups had a significant reduction in pain scores at 30 minutes and there was no statistical difference in the degree of pain reduction across the 3 groups (SEE FIGURE 3). The median VAS pain score following treatment was 40. There was not a significant difference in the need for rescue analgesia or the rate of adverse effects across the groups.

Bottom Line: Although this study is limited in that patients were enrolled only during investigator clinical shifts and they did not examine the need for pain control beyond 1 hour, this evidence would suggest that lower doses of ketorolac may be effective in managing the pain associated with renal colic in the ED.

MOTOV ET AL

This is a prospective randomized, double-blind trial of 3 treatment arms for pain management of renal colic with a hypothesis that the addition of lidocaine to ketorolac would provide superior pain management to either drug alone. A convenience sample of 150 adults aged 18-64 presenting between November 2016 and October 2018 with pain between the costal margin and groin suspected by the EM physician of being caused by renal colic were enrolled. Treatment was either lidocaine 1.5 mg/kg, lidocaine 1.5 mg/kg and 30 mg ketorolac, or 30 mg of ketorolac alone. Patients who received NSAIDs within 4 hours of presentation or who were greater than 100 kg were excluded. While pain scores improved in all treatment groups, they did not identify a benefit when the two drugs were used together as compared to either drug when used alone (SEE FIGURE 2). While they were not powered to detect safety differences, there did appear to be more adverse effects including dizziness, nausea and vomiting, and perioral numbness in the combination therapy group.

Bottom line: In our clinical practice where ketorolac is used frequently to manage the pain associated with renal colic, we do not see a benefit to the addition of lidocaine.

SAFDAR ET AL

This is a prospective randomized, double-blind trial with 3 treatment arms comparing ketorolac to morphine as well as the combination of the two drugs given together. Patients between the ages of 18 and 55 presenting with a clinical diagnosis of renal colic and pain > 5 were included. If patients had not previously been diagnosed with kidney stones, CT was used to confirm the diagnosis. Patients who received analgesia within 6 hours of presentation were excluded. Treatment groups were 5 mg morphine, 15 mg ketorolac, or 5mg morphine and 15 mg ketorolac together. All 3 groups were given promethazine as needed for nausea. Pain was assessed 20 minutes following administration and if pain persisted, a second dose of the original medication was given. 130 patients were enrolled across the 3 groups. While all 3 groups had a reduction in their pain scores, there was a synergistic effect of morphine and ketorolac observed with patients in the combination group having greater reduction in their pain scores and less need for rescue morphine at 40 minutes (SEE FIGURE 3). Limitations of this study include the small sample size, lack of a confirmed diagnosis in all patients (including a lack of evidence of kidney stone in 12 of 76 patients who underwent CT scan) and the standard dosing of morphine at 5 mg which is a weight-based drug.

Bottom Line: Patients with the presumed diagnosis of renal colic had better pain scores when morphine and ketorolac were given in combination versus either alone.

Although not specifically addressed in these papers, in many cases, renal colic does remain a clinical diagnosis and we should initiate pain management early for this condition.
Ketorolac has been shown to be effective in the management of pain related to renal colic and if we are concerned about side effects or renal risk, there is evidence to support equal analgesic effects of lower doses (10 or 20 mg).
Lidocaine does not appear to provide benefit over ketorolac either when given alone or when given in combination with ketorolac for pain management.
There may be an added benefit in pain reduction to using ketorolac and morphine together and this can be considered when ketorolac alone does not provide adequate pain management.