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Three Part Question

In [adult patients presenting to the emergency department with renal colic], is [IV lidocaine as effective as IV opioids] for [pain control?]

Clinical Scenario

A 24 year old male presents to the emergency department with sudden onset of right flank pain radiating to the groin. A clinical diagnosis of renal colic is made. However, the patient is allergic to opioids. You recall a recent study describing treatment with parenteral lidocaine for intractable renal colic.

Search Strategy

Medline 1966-07/16 using OVID interface, Cochrane Library (2016), and Embase
[(exp renal calculi/ or exp kidney calculi/ or exp renal colic/ or exp renal lithiasis/ or exp ureteral lithiasis) AND (exp lidocaine/ or exp lignocaine)].

Search Outcome

34 studies were identified; two clinical trials addressed the clinical question.
An internet search uncovered a case series by the authors of RCT published in 2012.

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Soleimanpour et al. 2012 Iran	240 Adult patients, aged 18-65 years, presenting to the emergency department for renal colic. Patients were randomized to recieve either a single intravenous dose of lidocaine (1.5mg/kg) or a single dose of intravenous morphine (0.1mg/kg).	Randomized controlled trial	Responded to treatment.	Lidocaine group 90% of patients, morphine group 70%.	Unclear how the authors defined "responded" as an outcome. The patients studied in this article were from Iran, a country that does not use IV Toradol or IV dilaudid, medications frequently used in the USA for renal colic. It remains unknown how well IV lidocaine would compare to these two medications for the treatment of renal colic.
			Pain at presentation (VAS mean+/- SD)	Lido caine group 9.65+/-0.88, morphine group 9.74+/-0.63 P=0.365.
			Pain at 5 minutes (VAS mean+/- SD)	Lidocaine group 3.18+/-2.27, morphine group 4.45+/-2.16 P=0.0001.
			Pain at 10 minutes (VAS mean+/- SD)	Lidocaine group 1.83+/-1.59, morphine group 2.89+/-2.07 P=0.0001.
			Pain at 15 minutes (VAS mean+/- SD)	Lidocaine group 1.37+/-1.32, morphine group 2.55+/-1.52 P=0.0001.
			Pain at 30 minutes (VAS mean+/- SD)	Lidocaine group 1.13+/-1.15, morphine group 2.23+/-1.57 P=0.0001.
Firouzian et al. 2016 Iran	110 adults, aged 18-50 years, presenting to the emergency department with renal colic. Patients received either intravenous morphine (0.1mg/kg) plus lidocaine (1.5mg/kg) or intravenous morphine (0.1mg/kg) plus normal saline 0.9% as placebo.	Randomized controlled trial	Time to be pain-free (median).	M+L group 87 minutes (95% CI 74-95 minutes), M group 100 minutes (95% CI 90-110 minutes) P=0.071.	This study did not show a significant difference in the primary outcome; time to being pain free. There was a trend favoring IV lidocaine plus morphine but because the sample size in the study was small, no significant difference was found.
			Time to be nausea-free (median).	M+L group 27 minutes (95% CI 14-39 minutes), M group 58 minutes (95% CI 42-75 minutes) P<0.001.

Comment(s)

Patients suffering from renal colic often present to the ED with intractable pain. Commonly, narcotic medications are used to control the patient’s pain. It is well known that intravenous narcotics have many side effects including drowsiness, hypotension, respiratory depression and slow gastrointestinal motility. Intravenous lidocaine has been shown to have a safe medication profile when used at low doses (1.5 mg/kg) and is effective in the treatment of renal colic. It has been shown to be more effective than intravenous morphine in pain control. Furthermore, if combined with intravenous morphine, patients will likely have less nausea.

Editor Comment

The studies presented do suggest that lidocaine may be of some benefit in renal colic. However, lidocaine was not compared with non-steroidal anti-inflammatory drugs, which, when available, should remain the first line of treatment (Afshar et al. Cochrane Systematic Review. doi: 10.1002/14651858.CD006027.pub2). VAS, visual analogue scale.

Clinical Bottom Line

In adult patients presenting to the ED for renal colic, intravenous lidocaine has been shown to be more affective for pain control than intravenous morphine. Furthermore, if intravenous lidocaine is used along with intravenous morphine, patients will be nausea free significantly sooner.

References

1. Soleimanpour H, Hassanzadeh K, Vaezi H, et al. Effectiveness of intravenous lidocaine versus intravenous morphine for patients with renal colic in the emergency department BMC Urol 2012;12:13.
2. Firouzian A, Alipour A, Dezfouli HR, et al. Does lidocaine as an adjuvant to morphine improve pain relief in patients presenting to the ED with acute renal colic? A double-blind, randomized controlled trial. Am J Emerg Med 2016;34:443–8.