Ketorolac at Lower Doses for Analgesic Pain Control in ICU: A Pilot Feasibility Study

Opiates are commonly used to control pain in critically ill patients in the ICU. However, increased rates of opiate use in hospital may lead to increased prescription-based opiate dependence after leaving the ICU. This may contribute to the ongoing opiate epidemic across the world. Other medications that can reduce pain, like non-steroidal anti-inflammatory drugs (NSAIDs), are being studied in critically ill patients. These drugs block the enzyme, cyclooxygenases (COX), which causes inflammation in the body. Blocking these enzymes can decrease pain, fever, and inflammation. Traditionally, NSAIDs are not commonly used in critically ill patients due to the perceived risk of gastrointestinal (GI) bleeding and acute kidney injury (AKI). However, many critically ill patients are already receiving medications and treatments to prevent GI bleeding and AKI and are closely monitored so these medications may be useful in reducing pain for these patients.

The purpose of this study is to see whether NSAIDs can be used safely in critically ill patients to reduce the dose of opiates required for pain control. This is a pilot study or a feasibility study, which is not expected to answer the question definitively. Its main purpose is to determine if NSAIDs could reduce the use of opiates in critically ill patients while in the ICU. The data collected in this study may be used in a larger study in the future.

Purpose: The purpose of this study is to determine the feasibility of conducting a future, adequately powered large-scale randomized trial, while evaluating the safety and efficacy of an intravenous NSAID (e.g., ketorolac) plus usual care as compared to placebo plus usual care in critically ill patients.

Hypothesis: The investigators hypothesize that this single-centre pilot study will demonstrate that NSAIDs administration is feasible and safe in ICU patients and may potentially reduce opiate use in ICU patients with pain.

Justification: Pain control in ICU is difficult to achieve given that opiates are the mainstay of analgesia in critically ill patients, but this is not without unintended side effects, especially unintended consequences of possible future drug dependence or addictions. Given that opiates and other adjunctive pain medications (e.g., acetaminophen) are being utilized at high proportional rates, and that NSAIDs are used at relatively low rates (due to the theoretical risk of increased AKI and GI bleeds), there is potential for practice change for increased NSAID use at lower doses to reduce pain and opiate use, while not increasing risks.

Objectives: The primary objective of this pilot trial is to assess the feasibility of a larger clinical trial utilizing NSAIDs in the ICU for patients with pain. The primary outcomes of the pilot feasibility trial are: recruitment and consent rates, proportion of eligible participants who are randomized vs. not randomized, retention and protocol adherence rates.

The secondary objectives are to assess safety of the proposed trial (e.g. gastrointestinal bleeding, acute kidney injury, death) and efficacy outcomes (e.g. participant pain scores, opiate and other analgesia usage).

Research Methods/Procedures: The investigators have designed KETOROLAC-ICU as a pilot randomized controlled trial (prospective, single centre, parallel-group, concealed, blinded) examining the use of low-dose ketorolac for critically ill patients.

Eligibility Criteria:
Inclusion Criteria:

* Age \> 18 years
* Admission to intensive care unit (ICU)
* Participants with pain (Critical Care Pain Observation Tool \[CPOT\] \> 1 and/or self-report pains score \>1 on visual analogue scale \[VAS\] or numerical rating scale \[NRS\])

Exclusion Criteria:

* Serum Cr \> 100 mmol/L for females, and \>130 mmol/L for males
* Ongoing ACEi (angiotensin converting enzyme inhibitor)/ARB (angiotensin receptor blocker) use in ICU
* Known hyperkalemia \> 5.5
* Pre-existing chronic kidney disease (CKD Stage \> 3), defined by a serum Cr \> 100 mmol/L for females, and \>130 mmol/L for males (at the time of screening, based on pre-hospital stable outpatient baseline values)
* New acute kidney injury KDIGO Stage \> 2 (increased more than \> 2-to-3 times in serum creatinine above baseline AND/OR \<0.5mL/kg/hour urine output for \>12 hours)
* Pre-existing gastrointestinal bleeding (within 12 weeks of hospital admission, requiring hospitalization or medical evaluation), new peptic ulcer disease, esophagitis, esophageal varices within the last 3 months
* Active gastric / duodenal / peptic ulcer, active GI bleeding
* Prior contraindications/allergies to NSAIDS or stress ulcer prophylaxis, specifically if a participant has had an anaphylactic reaction (asthma or urticaria) or non-anaphylactic asthma reaction to NSAIDs or any stress ulcer prophylaxis, e.g. proton pump inhibitor, histamine-2-blockers, etc. (e.g. proton pump inhibitor, histamine-2-blockers, etc.)
* Complete or partial syndrome of ASA-intolerance (e.g. rhinosinusitis, urticaria/angioedema, nasal polyps, asthma)
* Participants who are not receiving stress ulcer prophylaxis (e.g. proton pump inhibitor, histamine-2-blockers, etc.) while in ICU
* Any active bleeding (requiring any blood products or adjunctive coagulation agents, any output of blood \>100 mL/hr, e.g. chest tube drainage, abdominal cavity drain, etc.)
* Currently receiving NSAID(s) for another indication
* Inflammatory bowel disease (e.g. participants with prior diagnosis of Crohn's disease or ulcerative colitis)
* Receiving probenecid, oxpentifylline or pentoxifylline
* Active ischemic heart disease (acute myocardial infarction, acute coronary syndrome during current hospital admission)
* Moderate-severe uncontrolled heart failure (New York Heart Association: Class II-IV)
* Moderate to severe liver impairment or active liver disease (Operational definition: participants with prior history of Child-Pugh class B (moderate) or C (severe) liver cirrhosis, OR Model for End-Stage Liver Disease-Sodium (MELD-Na) score \>25, OR active acute liver failure: severe acute liver injury with encephalopathy and impaired synthetic function International Normalized Ratio (INR) \>1.5 with or without pre-existing liver disease)
* Active cerebrovascular bleeding or stroke (cerebrovascular accident, transient ischemic attacks and/or amaurosis fugax, e.g. participants with active stroke symptoms within current hospital admission)
* Cerebrovascular bleeding or other bleeding disorders
* Coagulation disorders, post-operative patients with high haemorrhagic risk or incomplete haemostasis in patients with suspected or confirmed cerebrovascular bleeding
* Neuraxial (epidural or intrathecal) administration of ketorolac tromethamine injection due to its alcohol content
* Rhabdomyolysis (creatinine kinase \>5000 U/L)
* Recent transplant (during same hospital admission, e.g., heart, lung, kidney, liver, etc.)
* Known allergy to ketorolac or other NSAIDs
* Participants expected to stay in ICU \< 48 hours
* In the opinion of the attending physician, expected death or withdrawal of life-sustaining treatments within 48 hours
* Participant is known to be pregnant and/or breastfeeding
* Most responsible physician, participant, or substitute decision maker declines study participation (and reason)