Evaluation of the Effects of Ketorolac Dose on Duration of Analgesia in Emergency Department (ED) Renal Colic Patients

Pain is a common emergency department complaint. With various types of analgesics available, the optimal drug is one that provides adequate pain management with minimal side effects. The goal is to effectively treat the patient while maintaining adequate flow in the emergency department. In cases of moderate to severe pain in emergency departments, opioids have been the gold standard.1 Opiates, such as morphine, are associated with side effects that can be distressing to the patient, as well as, costly to the department. Prescribing opiates includes a reluctance in administering sufficient opioid dosing due to fear of tolerance and dependency.2

It has been demonstrated in other studies that the standard dosing of ketorolac is higher than needed to achieve analgesia but have failed to show to what duration of time analgesia is maintained between the dosages. The study will compare the analgesic efficacy of two doses of intravenous ketorolac (15mg and 30mg) for acute flank pain in the Emergency Department (ED), such as renal colic, and how efficacious the pain was controlled at 120 minutes or upon discharge. Motov et al evaluated the effectiveness of ketorolac in moderate to severe pain with a primary endpoint of 30 minutes, however the peak onset of ketorolac is 120 to 180 minutes.

Our study may further investigate the ceiling dose of intravenous ketorolac. The primary outcome of both Motov et al and Eidinejad et al was pain reduction 30 minutes after ketorolac administration.3,4 These studies differed in the aspect that Eidinejad et al study examined pain reduction up to 60 minutes, while Motov et al observed up to 120 minutes after administration of ketorolac.3,4 Ketorolac has a peak time of onset at 2 to 4 hours. These studies are not observing ketorolac at its optimal analgesic potency. Therefore, a study is proposed to compare 15 mg vs 30 mg intravenous ketorolac with the primary outcome being pain reduction in renal colic at 120 minutes. Nephrolithiasis and ureterolithiasis are the most common diagnoses in the emergency department for which ketorolac is prescribed.5 This study may further evaluate optimal intravenous ketorolac dosing in pathology it is known to be the most advantageous.

Inclusion criteria

Patients will be included if they present to the Emergency Department with (all of the following):

• Adult emergency department patients < 65 years old
• One or more of the following common ED chief complaints associated with the suspected diagnosis of renal colic. These chief complaints include but are not limited to: flank pain, back pain, abdominal pain, left and/or right lower quadrant pain, and/or pelvic pain
• Pain score of 4 or greater on the 0-10 NRS
• Determination of treatment with IV ketorolac

Exclusion criteria

Patients will be excluded if any of the following apply:

• Allergy to ketorolac
• Pregnant patients
• Previously received analgesic medications within 4 hours prior to administration of ketorolac in our ED
• Known or stated history of renal insufficiency
• Body weight < 50 kg
• Age greater than 65 years
• Patients that do no read/write Spanish or English