Parenteral lidocaine for treatment of intractable renal colic: a case series

INTRODUCTION: We report a case series of successful treatment of intractable renal colic using parenteral lidocaine. CASE PRESENTATION: Because of inconsistent responses to standard treatment with opioids and non-steroidal anti-inflammatory drugs in patients with renal colic pain, we decided to begin a trial of a single intravenous dose of lidocaine (approximately 1.5 mg/kg) slowly in eight patients with intractable renal colic who were referred to our emergency medicine department. The patients were six men and two women with a mean age at diagnosis of 34.62 years (age range, 28 to 42 years). The patients were of Iranian ethnic origin. The patients' degree of pain, based on Visual Analog Scale score upon entering our emergency medicine department, was recorded 10, 20, and 30 minutes after lidocaine injection. The patients' degree of pain decreased from a mean Visual Analog Scale score (±SD) of 8.87 ± 0.99 (95% confidence interval (95% CI) 8.04 to 9.70) to a mean Visual Analog Scale score (±SD) of 1 ± 2.82 (95% CI -1.36 to 3.36) before and 30 minutes after lidocaine treatment, respectively. Two of eight patients experienced transient mild dizziness, and three of eight patients experienced minimal slurring of speech. No patient experienced serious adverse events. CONCLUSION: Parenteral lidocaine treatment can reduce pain dramatically or subtly.