Ketamine Pilot Study

Phase 4

Terminated

Conditions: Rattlesnake Envenomation

Interventions: Drug: Ketamine
Drug: Fentanyl

Registration Number: NCT05379179

Lead Sponsor: Meghan Spyres

Brief 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).

Detailed Description: Multiple studies have shown ketamine to be safe and effective agent for acute pain syndromes. RSEs classically result in severe pain that can be difficult to control, despite use of opioids, non-opioid analgesics, and positioning techniques, including splinting and elevation. Furthermore, the ongoing opioid epidemic pushes clinicians to explore non-opioid agents to avoid unnecessary exposure of patients to these high-risk medications. At least one small study has shown ketamine to be safe in rattlesnake envenomated patients.

Recruitment & Eligibility

Status: TERMINATED

Sex: All

Target Recruitment: 3

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

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Ketamine	Ketamine	Drug administration: A single dose of ketamine 0.3 mg/kg IV over 15 minutes. Time drug given will be documented Data obtained prior to med administration and then following medication administration at intervals of 15, 30, 60 and 120 minutes * Record vital signs (HR, B/P, resp rate, O2 sat) * Obtain and assess pain response scores 1. Pain Numerical Rating Score (NRS - 0-10) 2. Richmond Agitation Sedation Scale (RASS) 3. Side Effect Rating Scale for Dissociative Anesthesia (SERSDA) * Record any airway interventions required? If yes what? new supplemental O2/BVM/intubation, jaw thrust * Record any rescue meds, dose and time (Rescue medication - Fentanyl): * 1 mcg/kg IV fentanyl (0.5 mcg/kg if age \>55 yrs) * Defined as rescue if given \<30 min post study intervention for pain score \>5 or patient requesting additional medication. * Patient pain satisfaction score at discharge
Fentanyl	Fentanyl	Drug administration: A single dose of fentanyl 1mcg/kg IV, maximum 100 mcg, over 15 minutes. Time drug given will be documented Data obtained prior to med administration and then following medication administration at intervals of 15, 30, 60 and 120 minutes * Record vital signs (HR, B/P, resp rate, O2 sat) * Obtain and assess pain response scores 1. Pain Numerical Rating Score (NRS - 0-10) 2. Richmond Agitation Sedation Scale (RASS) 3. Side Effect Rating Scale for Dissociative Anesthesia (SERSDA) * Record any airway interventions required? If yes what? new supplemental O2/BVM/intubation, jaw thrust * Record any rescue meds, dose and time (Rescue medication - Fentanyl): * 1 mcg/kg IV fentanyl (0.5 mcg/kg if age \>55 yrs) * Defined as rescue if given \<30 min post study intervention for pain score \>5 or patient requesting additional medication. * Patient pain satisfaction score at discharge

Primary Outcome Measures

Name	Time	Method
Change in Pain Assessment Post Medication	30-120 minutes after drug administration	Pain will be assessed using a numerical rating scale (0-10, with 0 being no pain and 10 being the worst pain) at 30, 60, and 120 minutes after medication administration.

Secondary Outcome Measures

Name	Time	Method
Adverse Events	During hospitalization, up to 120 minutes	A subjects chart will be reviewed to determine whether rescue medication was needed or if there were any adverse medications effects