Intravenous Amide Anesthetics to Treat Pain Associated with Renal Colic in the Emergency Department: a System- atic Review

Renal colic affects 12% of the U.S. population, accounting for nearly 1% of emergency department (ED) visits. Current recommendations advocate narcotic-limiting multimodal analgesia regimens. The objec- tive of this review is to determine if in patients with renal colic (Population), intravenous (IV ) amide anesthetics (Intervention) result in better pain control, lower requirements for rescue analgesia, or less adverse medication effects (outcome) compared to placebo, non-steroidal anti-inflammatory drugs (NSAIDs), or opiates (Compar- isons).

Scholarly databases and relevant bibliographies were searched using a pre-designed system- atic review protocol and registered with PROSPERO. Inclusion criteria were: (1) randomized clinical trial (RCT), (2) age ≥ 18 years, (3) confirmed or presumed renal colic, (4) amide anesthetic administered IV. Eligible compar- ison groups included: placebo, conventional therapy, acetaminophen, NSAID, or opiate. The primary outcome was pain intensity at baseline, 30, 60, and 120 minutes. Trial quality was graded, and risk-of-bias was assessed.

Of the 3930 identified references, 4 RCTs (479 participants) were included. One trial (n=240) reported improved analgesia with IV lidocaine (LidoIV ) plus metoclopramide, compared to morphine. All other trials reported unchanged or less analgesia compared to placebo, ketorolac, or fentanyl. Very severe heterogeneity (I 2 = 88%) precluded pooling data.

Current evidence precludes drawing a firm conclusion on the efficacy or superiority of LidoIV over traditional therapies for ED patients with renal colic. Evidence suggests Li- doIV may be an effective non-opiate analgesic alliterative; however, it’s efficacy may not exceed that of NSAIDs or opiates. Further study is needed to validate the potential improved efficacy of LidoIV plus metoclopramide.