Ketamine Pilot Study
Condition: Rattlesnake Envenomation
MeSH terms: Poisoning
Intervention: Ketamine; Fentanyl
Intervention description: This study will compare patient-reported pain scores after receiving either ketamine or fentanyl for the treatment of acute pain due to a rattlesnake bite.; This study will compare patient-reported pain scores after receiving either ketamine or fentanyl for the treatment of acute pain due to a rattlesnake bite.
Intervention MeSH terms: Fentanyl; Ketamine
Phase: Phase 4
Study type: Interventional
Primary purpose: Treatment
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Following enrollment, subject will be randomly assigned to receive either ketamine, or fentanyl. A randomization masterlist has been developed that will be used to assign drug. Subjects will be assigned in sequential order. Each block will alternate between each drug. Subjects will have 50/50 chance of being assigned to ketamine or fentanyl.
Masking: Single (Participant)
Masking description: The blinding of the subjects is done by the investigators which is the block randomization; each block will alternate between each drug ketamine or fentanyl. Subject will not be told which pain medication they will receive.
Enrollment: 3.0
Sex: All
Minimum age: 18 Years
Maximum age: 100 Years
Healthy volunteers: No
Keywords: Acute pain after rattlesnake bite; Rattlesnake envenomation; low dose ketamine; pain dose ketamine

Summary:

      This is a pilot study to evaluate pain responses from two different approved medications
      (ketamine and fentanyl) in the treatment of pain after rattlesnake envenomation (RSE). Both
      medications are currently used in standard practice to treat both acute and chronic pain and
      are options for pain management after RSE. Multiple studies exist showing ketamine to be both
      safe and effective for the treatment of acute pain, and to be as good as or better than
      opioids for this indication. The specific comparison of ketamine to fentanyl, however, has
      never been studied for the treatment of acute pain after rattlesnake envenomation in the
      United States. The investigators plan to measure pain scores after a single dose of ketamine
      or fentanyl in patients shortly after being envenomated, followed by continued treatment of
      pain guided by the treating doctor. There will be no restrictions on additional pain
      medications given and no other changes to the treatment of these patients during their
      hospitalization. This research is important because pain after RSE can be difficult to
      control and may require frequent, high doses of opioids for several days. An effective
      non-opioid medication would be helpful both to better-control pain and to reduce exposure to
      opioids in this patient population. This study will compare patient-reported pain scores
      after receiving a single dose of ketamine or fentanyl in patients with rattlesnake bites who
      have been admitted to the toxicology service at Banner - University Medical Center Phoenix
      (BUMCP).
    

Eligibility criteria:

        Inclusion Criteria:

          -  Ages ≥ 18 years.

          -  Able to speak and understand English.

          -  RSE requiring IV pain medication for NRS pain score > 5.

          -  No allergy to ketamine or fentanyl.

          -  Ability to provide informed consent.

          -  ≤ 24 hours from envenomation.

        Exclusion Criteria:

          -  Pregnant or lactating.

          -  Prisoners.

          -  Refugees.

          -  History of schizophrenia.

          -  Clinically intoxicated.

          -  On buprenorphine therapy.

          -  History of uncontrolled hypertension

          -  Increased intracranial pressure

          -  Systemic envenomation