HemorrhoidsPhase 4NCT04248205
Ketamine for Post-operative Analgesia in Hemorrhoidectomy
A Phase 4 study testing Ketamine in people with Hemorrhoids, run by University of Oklahoma at 1 site in United States.
Trial summary
This is a prospective, randomized study of ketamine versus no ketamine in approximately 100 patients undergoing hemorrhoidectomy for Grade III or IV hemorrhoids. The participants will be blinded to which treatment arm they are assigned, because participants will be under anesthesia when the ketamine is administered. Read more about this study
- Who is it for?
- Ages 18 to 100 years
- Conditions the study is for
- Hemorrhoids
- What is being tested?
- Ketamine
- Type of treatment
- Injection or infusion
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 100 participants
- Where
- 1 siteUnited States
- Study dates
- 15 Jun 2020to Jul 2027
- Phase
- Phase 4
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 100 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Adults aged 18-100
- Undergoing a hemorrhoidectomy for Grade III or IV hemorrhoids.
Who cannot join
- Inability to undergo general anesthesia
- Contraindications to hemorrhoidectomy
- History of schizophrenia or other hallucinatory psychiatric illnesses
- History of psychosis
- Chronic narcotic usage defined as either having a pain contract with a pain management specialist and no narcotic usage for one month prior to hemorrhoidectomy.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
United States1 site, 1 recruiting
- Recruiting
University of Oklahoma Health Sciences Center
Oklahoma City, Oklahoma, 73104
Steven Carter, 405-271-8001 ext. 55000, steven-carter@ouhsc.edu
About this study
Official title: Intra-operative Use of Ketamine for Post-Operative Analgesia in Patients Undergoing Hemorrhoidectomy: A Prospective, Randomized Controlled Trial.
This is a prospective, randomized study of ketamine versus no ketamine in approximately 100 patients undergoing hemorrhoidectomy for Grade III or IV hemorrhoids. The participants will be blinded to which treatment arm they are assigned, because participants will be under anesthesia when the ketamine is administered. The investigators will know whether the participant receives ketamine or not.
Read the detailed description
Participants will be randomized into 2 groups: intraoperative ketamine infusion during operation or routine anesthesia with no ketamine. Participants are pre-medicated in the operating room with the same regimen: Gabapentin 300mg, Ultram 50mg, and Tylenol 1000mg.
For participants in the ketamine group, a pain dose of ketamine 0.3mg/kg IV bolus dosing will be given prior to incision. If the procedure lasts longer than 1 hour, an additional bolus dose will be given. All participants will undergo general anesthesia and receive routine anesthesia care, aside from ketamine verus no ketamine. All participants will also receive standard local anesthesia including a local regional perianal nerve block.
The procedure will be performed by three different surgeons, with the surgery done the same way using ligasure hemorrhoidectomy. Participants will all be sent home with the same post-operative instructions and pain medications to include: Tylenol 1000mg, oxycodone 5mg, ibuprofen 800mg, fiber/miralax, and tub baths twice daily for 15 minutes.
A patient pain handout will be given to participants upon discharge with instructions to rate pain according to a numeric rating scale and the Wong-Baker FACES pain scale. Participants will be contacted by a member of the research team to assess their post-operative pain based on a numeric rating scale. All participants will undergo post-operative clinic follow-up at 2 weeks post-operation. At that time they will be instructed to bring their oxycodone bottle to assess how many pills the participant required. The clinic medical assistant will count the number of remaining pills and record this in the electronic medical record. If a participant forgets their pain scale record or medications, a post-operative phone interview will be performed after the clinic appointment to gather this information.
The investigators will randomize 50 participants to the ketamine group and 50 participants to the placebo group. Study will take place until all participants have been analyzed, approximately 8-12 months. Randomization will occur using a statistical method with study arms placed into individual envelopes that will be stored at the University of Oklahoma (OU) Surgery Center. The investigator will blindly pull an envelope from the stack which will identify the participant's treatment arm. The participants will be blinded and not informed of their arm of the study as to not create bias toward subjective pain. Practitioners will not be blinded for ease of medication administration. The procedures will occur at OU Surgery Center by one of three surgeons. Anesthesiologists will administer ketamine based on study arm.
- Conditions
- Hemorrhoids
- Being tested
- Ketamine
- Keywords
- hemorrhoidectomy, ketamine, post operative pain
- Medical subject headings
- Hemorrhoids, Pain, Postoperative
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
KetamineDrug
Standard general anesthesia PLUS ketamine will be given for post-operative analgesia
| Study group | Role | What they receive |
|---|---|---|
| Intraoperative ketamine infusion | Active comparator | Subjects in this group will receive standard anesthesia during surgery and a dose of ketamine at 0.3 mg/kg IV bolus prior to surgical incision. If the procedure lasts more than 1 hour, an additional bolus dose will be given. Receives: Drug: Ketamine |
| Control group | No intervention | This group will only receive the standard anesthesia during surgery with no ketamine. |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in post-operative narcotic usage
Standardized pain control regimen with ketamine; at two week surgical follow-up visit patient will bring their oxycodone prescription and we will count the number of pills that were taken.
Measured: two weeks post-operation
Secondary outcomes (1)
Change in post-op pain
Wong-Baker FACES Pain Rating Scale, which ranges from 0 to 10, with 0 being represented by a happy face indicating "No Hurt" to 10, represented by a crying face, indicating "hurts like the worst pain imaginable".
Measured: Post-op days 1, 3, 5, 7, and 10
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Jan 2020
- Study start15 Jun 2020
- Primary completionJan 2027 (estimated)
- Study completionJul 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (3)Papers the sponsor has linked to this study.
- Other trials for HemorrhoidsStudies of the same condition, open and under way.
- More trials run by University of OklahomaThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase 4
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 100 participants (estimated)
Sponsor and investigators
- Lead sponsor
- University of Oklahoma
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Steven N Carter, MD, Principal investigator, University of Oklahoma
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04248205
- Sponsor's protocol ID
- 11475
- Status last verified
- Mar 2026
- First submitted
- 27 Jan 2020
- Last updated
- 1 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Himmelseher S, Durieux ME. Ketamine for perioperative pain management. Anesthesiology. 2005 Jan;102(1):211-20. doi: 10.1097/00000542-200501000-00030. No abstract available.
PubMed 15618805Gorlin AW, Rosenfeld DM, Ramakrishna H. Intravenous sub-anesthetic ketamine for perioperative analgesia. J Anaesthesiol Clin Pharmacol. 2016 Apr-Jun;32(2):160-7. doi: 10.4103/0970-9185.182085.
PubMed 27275042Luggya TS, Roche T, Ssemogerere L, Kintu A, Kasumba JM, Kwizera A, Tindimwebwa JV. Effect of low-dose ketamine on post-operative serum IL-6 production among elective surgical patients: a randomized clinical trial. Afr Health Sci. 2017 Jun;17(2):500-507. doi: 10.4314/ahs.v17i2.25.
PubMed 29062346
Study at a glance
From the registry record, last updated by the sponsor on 1 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Intra-operative Use of Ketamine for Post-Operative Analgesia in Patients Undergoing Hemorrhoidectomy: A Prospective, Randomized Controlled Trial.
- ClinicalTrials.gov ID
- NCT04248205
- Acronym / sponsor ID
- 11475
- Conditions
- Hemorrhoids
- Keywords
- hemorrhoidectomy, ketamine, post operative pain
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 100 participants (estimated)
- Lead sponsor
- University of OklahomaUniversity, hospital or other
- Study start
- 15 Jun 2020 (actual)
- Primary completion
- Jan 2027 (estimated)
- Study completion
- Jul 2027 (estimated)
- First posted
- 30 Jan 2020 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This is a prospective, randomized study of ketamine versus no ketamine in approximately 100 patients undergoing hemorrhoidectomy for Grade III or IV hemorrhoids. The participants will be blinded to which treatment arm they are assigned, because participants will be under anesthesia when the ketamine is administered. The investigators will know whether the participant receives ketamine or not.
Detailed description
Participants will be randomized into 2 groups: intraoperative ketamine infusion during operation or routine anesthesia with no ketamine. Participants are pre-medicated in the operating room with the same regimen: Gabapentin 300mg, Ultram 50mg, and Tylenol 1000mg.
For participants in the ketamine group, a pain dose of ketamine 0.3mg/kg IV bolus dosing will be given prior to incision. If the procedure lasts longer than 1 hour, an additional bolus dose will be given. All participants will undergo general anesthesia and receive routine anesthesia care, aside from ketamine verus no ketamine. All participants will also receive standard local anesthesia including a local regional perianal nerve block.
The procedure will be performed by three different surgeons, with the surgery done the same way using ligasure hemorrhoidectomy. Participants will all be sent home with the same post-operative instructions and pain medications to include: Tylenol 1000mg, oxycodone 5mg, ibuprofen 800mg, fiber/miralax, and tub baths twice daily for 15 minutes.
A patient pain handout will be given to participants upon discharge with instructions to rate pain according to a numeric rating scale and the Wong-Baker FACES pain scale. Participants will be contacted by a member of the research team to assess their post-operative pain based on a numeric rating scale. All participants will undergo post-operative clinic follow-up at 2 weeks post-operation. At that time they will be instructed to bring their oxycodone bottle to assess how many pills the participant required. The clinic medical assistant will count the number of remaining pills and record this in the electronic medical record. If a participant forgets their pain scale record or medications, a post-operative phone interview will be performed after the clinic appointment to gather this information.
The investigators will randomize 50 participants to the ketamine group and 50 participants to the placebo group. Study will take place until all participants have been analyzed, approximately 8-12 months. Randomization will occur using a statistical method with study arms placed into individual envelopes that will be stored at the University of Oklahoma (OU) Surgery Center. The investigator will blindly pull an envelope from the stack which will identify the participant's treatment arm. The participants will be blinded and not informed of their arm of the study as to not create bias toward subjective pain. Practitioners will not be blinded for ease of medication administration. The procedures will occur at OU Surgery Center by one of three surgeons. Anesthesiologists will administer ketamine based on study arm.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Single blind (participant)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Intraoperative ketamine infusion | Active comparator | Drug: KetamineSubjects in this group will receive standard anesthesia during surgery and a dose of ketamine at 0.3 mg/kg IV bolus prior to surgical incision. If the procedure lasts more than 1 hour, an additional bolus dose will be given. |
| Control group | No intervention | –This group will only receive the standard anesthesia during surgery with no ketamine. |
Who may qualify
- Ages
- 18 to 100 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- Adults aged 18-100
- Undergoing a hemorrhoidectomy for Grade III or IV hemorrhoids.
Key exclusion criteria (5 listed)
- Inability to undergo general anesthesia
- Contraindications to hemorrhoidectomy
- History of schizophrenia or other hallucinatory psychiatric illnesses
- History of psychosis
- Chronic narcotic usage defined as either having a pain contract with a pain management specialist and no narcotic usage for one month prior to hemorrhoidectomy.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| KetamineStandard general anesthesia PLUS ketamine will be given for post-operative analgesia | Drug | Intraoperative ketamine infusion |
Primary outcome
Change in post-operative narcotic usage
Time frame: two weeks post-operation
Standardized pain control regimen with ketamine; at two week surgical follow-up visit patient will bring their oxycodone prescription and we will count the number of pills that were taken.
1 secondary outcome
Change in post-op pain
Time frame: Post-op days 1, 3, 5, 7, and 10
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 1 Apr 2026.
- Background: PubMed 15618805Himmelseher S, Durieux ME. Ketamine for perioperative pain management. Anesthesiology. 2005 Jan;102(1):211-20. doi: 10.1097/00000542-200501000-00030. No abstract available.
- Background: PubMed 27275042Gorlin AW, Rosenfeld DM, Ramakrishna H. Intravenous sub-anesthetic ketamine for perioperative analgesia. J Anaesthesiol Clin Pharmacol. 2016 Apr-Jun;32(2):160-7. doi: 10.4103/0970-9185.182085.
- Background: PubMed 29062346Luggya TS, Roche T, Ssemogerere L, Kintu A, Kasumba JM, Kwizera A, Tindimwebwa JV. Effect of low-dose ketamine on post-operative serum IL-6 production among elective surgical patients: a randomized clinical trial. Afr Health Sci. 2017 Jun;17(2):500-507. doi: 10.4314/ahs.v17i2.25.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Steven N Carter, MD principal investigator
University of Oklahoma
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A Phase 4 study testing Ketamine in people with Hemorrhoids, run by University of Oklahoma at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 5 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 1 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
What does this phase mean?
Phase 4 studies take place after a treatment is approved, to learn more about its long-term benefits and risks in everyday use.
Not every study follows the same path, and some studies (observational studies, device studies) have no phase.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Steven N Carter, MD (405-271-8001 ext. 55000, steven-carter@ouhsc.edu), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in post-operative narcotic usage (time frame: two weeks post-operation). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04248205, which also lists 3 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 1 Apr 2026.