Rattlesnake Envenomation
Conditions
Keywords
Acute pain after rattlesnake bite, Rattlesnake envenomation, low dose ketamine, pain dose ketamine
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.
Interventions
DRUGKetamine
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.
DRUGFentanyl
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.
Sponsors
Meghan Spyres
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
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.
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.
Eligibility
Sex/Gender
ALL
Age
18 Years to 100 Years
Healthy volunteers
No
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| 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
| Measure | Time frame | Description |
|---|---|---|
| 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 |
Countries
United States
Participant flow
Recruitment details
Participants were recruited from patients hospitalized with rattlesnake bites at Banner University Medical Center between 05/2022 and 01/2024. The first participant was enrolled on 06/20/2022, and the last was enrolled in 08/2022.
Pre-assignment details
Of the 3 enrolled participants, 3 met inclusion criteria and were randomized.
Participants by arm
| Arm | Count |
|---|---|
| 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
Fentanyl: 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. | 2 |
| 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
Ketamine: 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. | 1 |
| Total | 3 |
Baseline characteristics
| Characteristic | Fentanyl | Ketamine | Total |
|---|---|---|---|
| Age, Categorical <=18 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical >=65 years | 0 Participants | 0 Participants | 0 Participants |
| Age, Categorical Between 18 and 65 years | 2 Participants | 1 Participants | 3 Participants |
| Ethnicity (NIH/OMB) Hispanic or Latino | 0 Participants | 0 Participants | 0 Participants |
| Ethnicity (NIH/OMB) Not Hispanic or Latino | 0 Participants | 1 Participants | 1 Participants |
| Ethnicity (NIH/OMB) Unknown or Not Reported | 2 Participants | 0 Participants | 2 Participants |
| Race (NIH/OMB) American Indian or Alaska Native | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Asian | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Black or African American | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) More than one race | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Native Hawaiian or Other Pacific Islander | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) Unknown or Not Reported | 0 Participants | 0 Participants | 0 Participants |
| Race (NIH/OMB) White | 2 Participants | 1 Participants | 3 Participants |
| Region of Enrollment United States | 2 participants | 1 participants | 3 participants |
| Sex: Female, Male Female | 0 Participants | 0 Participants | 0 Participants |
| Sex: Female, Male Male | 2 Participants | 1 Participants | 3 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk |
|---|---|---|
| deaths Total, all-cause mortality | 0 / 2 | 0 / 1 |
| other Total, other adverse events | 0 / 2 | 0 / 1 |
| serious Total, serious adverse events | 0 / 2 | 0 / 1 |
Outcome results
Primary
Change in Pain Assessment Post Medication
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.
Time frame: 30-120 minutes after drug administration
Population: Note there was only 1 patient in the Ketamine group thus medians represent this single patient value, no range calculated.
| Arm | Measure | Group | Value (MEDIAN) |
|---|---|---|---|
| Fentanyl | Change in Pain Assessment Post Medication | 30 minutes | 1 units on a scale |
| Fentanyl | Change in Pain Assessment Post Medication | 60 minutes | 1.5 units on a scale |
| Fentanyl | Change in Pain Assessment Post Medication | 120 minutes | 1.5 units on a scale |
| Ketamine | Change in Pain Assessment Post Medication | 30 minutes | 10 units on a scale |
| Ketamine | Change in Pain Assessment Post Medication | 60 minutes | 5 units on a scale |
| Ketamine | Change in Pain Assessment Post Medication | 120 minutes | 10 units on a scale |
Secondary
Adverse Events
A subjects chart will be reviewed to determine whether rescue medication was needed or if there were any adverse medications effects
Time frame: During hospitalization, up to 120 minutes
| Arm | Measure | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|
| Fentanyl | Adverse Events | 0 Participants |
| Ketamine | Adverse Events | 0 Participants |