Myth of the Month

IV fluid and narcotics for renal colic


A 40-year-old man presents with severe right flank pain for 1 hour. He has had this in the past when he passed a kidney stone. Urinalysis shows greater than 100 red blood cells per high power field (HPF). CT shows a 6-mm stone in the left ureter.

What do you recommend for therapy?

A. IV ketorolac and IV fluids.

B. IV morphine and IV fluids.

C. IV morphine.

D. IV ketorolac.

This is a common scenario, especially in emergency department settings and acute care clinics. Patients arrive in severe pain because of renal colic from kidney stones. Standard teaching that I received many years ago was that this patient should receive IV fluid to “help float the stone out” and narcotic pain medications to treat the severe pain the patient was in.

Dr. Douglas S. Paauw, professor of medicine in the division of general internal medicine at the University of Washington, Seattle

Dr. Douglas S. Paauw

Is there good evidence that this is the best therapy?

There are scant data on the practice of IV fluid for treatment of renal stone passage. W. Patrick Springhart, MD, and his colleagues studied 43 patients who presented to the ED for treatment of renal colic.1 All patients had CT evaluation for stones and received intravenous analgesia. Twenty patients were randomized to receive 2 L of normal saline over 2 hours, and 23 patients received minimal IV saline (20 mL/hour). There were no differences between the two groups in pain scores, narcotic requirements, or stone passage rates.

In an older study, Tom-Harald Edna, PhD, and colleagues studied 60 patients with ureteral colic, randomizing them to receive either no fluid or 3 L of IV fluid over 6 hours.2 There was no significant difference in pain between treatment groups.

A Cochrane analysis in 2012 concluded that there was no reliable evidence to support the use of high-volume fluid therapy in the treatment of acute ureteral colic.3

Standard treatment of pain for renal colic has been to use narcotics. In a randomized, double-blind trial comparing ketorolac and meperidine, William Cordell, MD, and his colleagues found that pain relief was superior in ketorolac-treated patients. Seventy-five percent of ketorolac patients had a 50% reduction in pain scores versus only 23% of the patients who received meperidine (P less than .001).4

Anna Holdgate and Tamara Pollock reviewed 20 studies that evaluated NSAIDs and narcotics for acute renal colic. They concluded that patients treated with NSAIDs had greater pain relief with less vomiting than did patients treated with narcotics.5

In the past decade, tamsulosin has been frequently used in patients with renal stones to possibly help with pain and promote more rapid stone passage. A recent randomized, controlled trial with 512 patients, authored by Andrew Meltzer, MD, and his colleagues, showed no improvement in stone passage rate in patients taking tamsulosin, compared with the rate seen with placebo.6

Previously published meta-analyses of multiple studies have shown a benefit to the use of alpha-blockers. Thijs Campschroer and colleagues included 67 studies that altogether included 10,509 participants.7 They found that the use of alpha-blockers led to possibly shorter stone expulsion times (3.4 days), less NSAID use, and fewer hospitalizations, with the evidence graded as low to moderate quality. Stone size seems to matter because use of alpha-blockers does not seem to make a difference for stones larger than 5 mm.

I think IV ketorolac would be the best of the options presented here for this patient. If a patient can safely take NSAIDs, those are probably the best option. There does not appear to be any reason to bolus hydrate patients with acute renal colic.

Dr. Paauw is a professor of medicine in the division of general internal medicine at the University of Washington, Seattle, and he serves as third-year medical student clerkship director at the University of Washington. Contact Dr. Paauw at


1. J Endourol. 2006 Oct;20(10):713-6.

2. Scand J Urol Nephrol. 1983;17(2):175-8.

3. Cochrane Database Syst Rev. 2012 Feb 15;(2):CD004926.

4. Ann Emerg Med. 1996 Aug;28(2):151-8.

5. BMJ. 2004 Jun 12;328(7453):1401.

6. JAMA Intern Med. 2018 Aug 1;178(8):1051-7.

7. Cochrane Database Syst Rev. 2018 Apr 5;4:CD008509.

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