AppendicitisPhase 4CASA RELAXNCT05966454
Complex And Simple Appendicitis: REstrictive or Liberal Post-operative Antibiotic eXposure - UCSF
A Phase 4 study of Appendicitis, run by University of California, San Francisco at 1 site in United States.
Trial summary
The purpose of this study is to demonstrate the safety, efficacy, and feasibility of short-course post-operative antibiotic treatment for simple and complicated appendicitis Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Appendicitis
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 42 participants
- Where
- 1 siteUnited States
- Study dates
- 6 Jun 2023to 16 Jul 2025
- Phase
- Phase 4
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Age ≥ 18 years
- Age ≥ 18 years
- Planned appendectomy (laparoscopic or open)
- Working telephone number or reliable method to contact patient after hospital discharge
Who cannot join
- Unable to consent
- Pregnant Women
- Prisoners
- Immunocompromised as determined by clinical team, or patients actively receiving steroids, chemotherapy, or immunosuppressing medications (for example tacrolimus), or patients with active hematologic malignancy affecting the immune system, leukopenia, or end-stage AIDS
- Heart failure
- Allergy to bupivacaine
Show all 14Show fewer
- Unlikely to comply with treatment or follow-up
- Inpatient consultation for appendicitis
- Clinically suspected of sepsis based on Sepsis-3 definition
- Current use of antibiotics for other indications
- Type 1 Diabetes or uncontrolled hyperglycemia
- Surgeon preference
- Patient preference
- Research team unavailable
Trial locations and contacts
1 site in 1 country.
United States1 site
Zuckerberg San Francisco General Hospital
San Francisco, California, 94110
About this study
Official title: Complex And Simple Appendicitis: REstrictive or Liberal Post-operative Antibiotic eXposure (CASA RELAX) Using Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR) -A Randomized Controlled Trial
The purpose of this study is to demonstrate the safety, efficacy, and feasibility of short-course post-operative antibiotic treatment for simple and complicated appendicitis
Read the detailed description
This is a single center, randomized controlled trial to determine if decreasing the amount of antibiotics after appendicitis surgery can decrease the risk of adverse effects associated with antibiotics while at the same time ensuring participant safety.
- Conditions
- Appendicitis
- Being tested
- Multiple standard of care antibiotics for appendicitis, at physicians' discretion
- Medical subject headings
- Appendicitis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Multiple standard of care antibiotics for appendicitis, at physicians' discretionDrug
Standard of Care Antibiotic use will be restricted to none or up to 24 hours of post-operative antibiotics.
Multiple standard of care antibiotics for appendicitis, at physicians' discretionDrug
Standard of Care Antibiotic use will be permitted for 24 hours or up to 4 days of post-operative antibiotics.
| Study group | Role | What they receive |
|---|---|---|
| Restricted Post-Operative Antibiotics Group | Experimental | Participants undergoing standard of care (SOC) with simple appendicitis will not receive post-operative antibiotics.
Participants undergoing standard of care with complicated (gangrenous or perforated) appendicitis will receive up to 24 hours of SOC post-operative antibiotics. Receives: Drug: Multiple standard of care antibiotics for appendicitis, at physicians' discretion |
| Liberal Post-Operative Antibiotics Group | Active comparator | Participants undergoing standard of care with simple appendicitis will receive 24 hours of post-operative SOC antibiotics
Participants undergoing standard of care with complicated (gangrenous or perforated) appendicitis will receive 4 days of post-operative SOC antibiotics. Receives: Drug: Multiple standard of care antibiotics for appendicitis, at physicians' discretion |
What is being measured
The primary outcome is the main question the study is designed to answer.
Number of Participants With Infectious/Antibiotic Complication
Infectious/antibiotic complication requiring antibiotic treatment only, Emergency Department visit, hospital readmission, percutaneous drainage, and operative intervention as assessed by treating physician.
Measured: Up to 30 days after appendicitis surgery
Number of Participant Deaths
Up to 30 days after appendicitis surgery
Measured: Up to 30 days after appendicitis surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted28 Jul 2023
- Study start6 Jun 2023
- Primary completion16 Jul 2025
- Study completion16 Jul 2025
Why it stopped: Not feasible to complete trial due to low enrollment rate. Enrollment terminated and inadequately powered to achieve statistical significance on primary and secondary study outcomes.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Other trials for AppendicitisStudies of the same condition, open and under way.
- More trials run by University of California, San FranciscoThe 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
- None (open label)
- Enrolment
- 42 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Francisco
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Lucy Kornblith, MD, Principal investigator, University of California, San Francisco
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05966454
- Sponsor's protocol ID
- 21-35457
- Acronym
- CASA RELAX
- Status last verified
- Oct 2026
- First submitted
- 30 Jun 2023
- Last updated
- 27 Oct 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- Yes
- FDA-regulated drug
- Yes
- FDA-regulated device
- No
- Individual data sharing
- Yes: Patient data will be shared with Denver health and combined with data from other independent sites for final analysis
Study at a glance
From the registry record, last updated by the sponsor on 27 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Complex And Simple Appendicitis: REstrictive or Liberal Post-operative Antibiotic eXposure (CASA RELAX) Using Desirability of Outcome Ranking (DOOR) and Response Adjusted for Duration of Antibiotic Risk (RADAR) -A Randomized Controlled Trial
- ClinicalTrials.gov ID
- NCT05966454
- Acronym / sponsor ID
- CASA RELAX / 21-35457
- Conditions
- Appendicitis
- Phase
- Phase 4
- Study type
- Interventional
- Recruitment status
- TerminatedReason stopped: Not feasible to complete trial due to low enrollment rate. Enrollment terminated and inadequately powered to achieve statistical significance on primary and secondary study outcomes.
- Enrolment
- 42 participants (actual)
- Lead sponsor
- University of California, San FranciscoUniversity, hospital or other
- Study start
- 6 Jun 2023 (actual)
- Primary completion
- 16 Jul 2025 (actual)
- Study completion
- 16 Jul 2025 (actual)
- First posted
- 28 Jul 2023 (actual)
- Results
- Posted 27 Oct 2026
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The purpose of this study is to demonstrate the safety, efficacy, and feasibility of short-course post-operative antibiotic treatment for simple and complicated appendicitis
Detailed description
This is a single center, randomized controlled trial to determine if decreasing the amount of antibiotics after appendicitis surgery can decrease the risk of adverse effects associated with antibiotics while at the same time ensuring participant safety.
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Restricted Post-Operative Antibiotics Group | Experimental | Drug: Multiple standard of care antibiotics for appendicitis, at physicians' discretionParticipants undergoing standard of care (SOC) with simple appendicitis will not receive post-operative antibiotics. Participants undergoing standard of care with complicated (gangrenous or perforated) appendicitis will receive up to 24 hours of SOC post-operative antibiotics. |
| Liberal Post-Operative Antibiotics Group | Active comparator | Drug: Multiple standard of care antibiotics for appendicitis, at physicians' discretionParticipants undergoing standard of care with simple appendicitis will receive 24 hours of post-operative SOC antibiotics Participants undergoing standard of care with complicated (gangrenous or perforated) appendicitis will receive 4 days of post-operative SOC antibiotics. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- Age ≥ 18 years
- Age ≥ 18 years
- Planned appendectomy (laparoscopic or open)
- Working telephone number or reliable method to contact patient after hospital discharge
Key exclusion criteria (14 listed)
- Unable to consent
- Pregnant Women
- Prisoners
- Immunocompromised as determined by clinical team, or patients actively receiving steroids, chemotherapy, or immunosuppressing medications (for example tacrolimus), or patients with active hematologic malignancy affecting the immune system, leukopenia, or end-stage AIDS
- Heart failure
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 |
|---|---|---|
| Multiple standard of care antibiotics for appendicitis, at physicians' discretionStandard of Care Antibiotic use will be restricted to none or up to 24 hours of post-operative antibiotics. | Drug | Restricted Post-Operative Antibiotics Group |
| Multiple standard of care antibiotics for appendicitis, at physicians' discretionStandard of Care Antibiotic use will be permitted for 24 hours or up to 4 days of post-operative antibiotics. | Drug | Liberal Post-Operative Antibiotics Group |
Primary outcome
Number of Participants With Infectious/Antibiotic Complication
Time frame: Up to 30 days after appendicitis surgery
Infectious/antibiotic complication requiring antibiotic treatment only, Emergency Department visit, hospital readmission, percutaneous drainage, and operative intervention as assessed by treating physician.
Number of Participant Deaths
Time frame: Up to 30 days after appendicitis surgery
Up to 30 days after appendicitis surgery
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 27 Oct 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Individual participant dataSharing planned: Yes. Patient data will be shared with Denver health and combined with data from other independent sites for final analysis
Related trials for Appendicitis
RecruitingObservational study
Prospective Comparison of Pro-Adrenomedullin, C-Reactive Protein, and Neutrophil-to-Lymphocyte Ratio for Diagnosing Acute Appendicitis
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PAINED: Project Addressing INequities in the Emergency Department
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Comparative Study Between Laparoscopic and Open Appendectomy of Complicated Appendicitis
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Feasibility and Safety of a Pediatric ERAS Protocol for Laparoscopic Appendectomy
Appendectomy, Laparoscopic, Acute Appendicitis
Not yet recruitingPhase 3
Piperacillin/Tazobactam Versus Ceftriaxone and Metronidazole for Children With Perforated Appendicitis
Appendicitis Perforated, Appendectomy, Laparoscopic
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. This study is not recruiting at the moment.
Lucy Kornblith, MD principal investigator
University of California, San Francisco
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 of Appendicitis, run by University of California, San Francisco 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 4 inclusion and 14 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: stopped early, as of the sponsor's last update on 27 Oct 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?
Yes. Results are posted in the registry (first posted 27 Oct 2026). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Number of Participants With Infectious/Antibiotic Complication (time frame: Up to 30 days after appendicitis surgery). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 27 Oct 2026.