Postoperative Nausea and VomitingBAROSPORNCT07797374
Postoperative Nausea, Vomiting and Pain After Bariatric Surgery - a National Registry Study
An observational study of Postoperative Nausea and Vomiting and Postoperative Pain, run by Umeå University at 2 sites in Sweden.
Trial summary
Around 4,000-5,000 bariatric (weight-loss) operations are performed in Sweden every year. Nausea, vomiting and pain are common immediately after these operations, cause considerable suffering and increase the intensity and length of hospital care. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Postoperative Nausea and Vomiting, Postoperative Pain, Obesity, Morbid
- How many people
- 30,000 participants
- Where
- 2 sitesSweden
- Study dates
- 1 Oct 2025to Dec 2028
- Phase
- Observational
- 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 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Study population: All adult patients registered in the Scandinavian Obesity Surgery Registry (SOReg) with a primary bariatric procedure during 2018-2027 and a matching operation record in the Swedish Perioperative Register (SPOR).
Who may be able to join
- Age 18 years or older
- Primary bariatric surgery registered in SOReg during 2018-2027
Who cannot join
- Revision bariatric surgery
- If more than one bariatric operation is registered for the same patient, only the primary operation is included
Trial locations and contacts
2 sites in 1 country. Contact the study team or a site near you to ask about taking part.
Sweden2 sites, 2 recruiting
- Recruiting
Sundsvall Hospital, Department of Anaesthesia and Intensive Care
Sundsvall, 851 86
- Recruiting
Umeå University, Department of Diagnostics and Intervention
Umeå, 901 87
Jakob Walldén, MD, PhD, +46 60 14 52 55, jakob.wallden@umu.se
Jakob Walldén, MD, PhD
About this study
Official title: Pain and Nausea in the Post-Anaesthesia Care Unit After Bariatric Surgery: A Registry Study Linking the Swedish Perioperative Register (SPOR) and the Scandinavian Obesity Surgery Registry (SOReg)
Around 4,000-5,000 bariatric (weight-loss) operations are performed in Sweden every year. Nausea, vomiting and pain are common immediately after these operations, cause considerable suffering and increase the intensity and length of hospital care. Bariatric surgery is one of the procedures with the highest risk of postoperative nausea and vomiting (PONV): about one third of patients experience PONV already in the recovery unit, and registry data indicate that around 40% report severe pain at the same stage.
This study links two national quality registries - the Swedish Perioperative Register (SPOR) and the Scandinavian Obesity Surgery Registry (SOReg) - to describe how often adult patients experience nausea, vomiting and pain in the post-anaesthesia care unit after primary bariatric surgery, and to identify patient, anaesthetic and surgical factors associated with these outcomes. The study tests whether total intravenous anaesthesia, the addition of a regional nerve block, and preoperative health-related quality of life are associated with PONV and pain, and whether early PONV or pain is associated with complications, unplanned hospital care or reoperation up to one year after surgery. The results are intended to show how well current evidence on preventing PONV and pain is applied in everyday practice and where care can be improved.
Read the detailed description
BACKGROUND Bariatric surgery is common in Sweden with 4,000-5,000 procedures per year. Data on each operation are recorded in the Swedish Perioperative Register (SPOR), covering more than 90% of all surgical procedures in Sweden with automatic data transfer from hospital IT systems, and in the Scandinavian Obesity Surgery Registry (SOReg), with a coverage of approximately 98% of bariatric surgery. Postoperative nausea and vomiting (PONV) and pain are frequent after bariatric surgery. Evidence-based guidelines exist, but 25-40% of surgical patients still experience PONV, and up to 50% may experience severe postoperative pain. Risk factors are validated at a general level but not specifically for bariatric surgery.
OBJECTIVES
- To describe the risk of early PONV and pain in the post-anaesthesia care unit (PACU) after primary bariatric surgery.
- To identify factors associated with early PONV and pain.
- To test the hypotheses that total intravenous anaesthesia (compared with inhalational anaesthesia) and the addition of a regional block are associated with lower risk of PONV or pain in the PACU; that poorer preoperative health-related quality of life (RAND-36) is associated with higher risk of PONV, pain and severe pain; and that PONV or pain in the PACU is associated with higher risk of postoperative complications up to one year after surgery. Separate hypothesis tests are performed for PONV and pain.
DESIGN Exploratory observational cohort study based on registry data. Patients aged 18 years or older with a primary bariatric procedure registered in SOReg during 2018-2027 are identified. Records are linked to SPOR by Uppsala Clinical Research Center (UCR) using personal identity number and date of surgery (+/- 3 days). If several SPOR records fall within the interval, each is included as a separate row with an index variable linking to the SOReg operation. Each individual is assigned a unique serial number and the dataset delivered to the research group contains pseudonymised data only. Data extractions are made at most once per year from 2025; the first analyses cover 2018-2023.
VARIABLES From SOReg: preoperative data (patient characteristics, comorbidity, laboratory values, preoperative work-up, RAND-36), operative data (procedure type, technique, intraoperative complications) and postoperative follow-up up to one year (complications, hospital care, reoperation). From SPOR: patient characteristics, process data, operative data (diagnosis, procedure, anaesthesia type, times, deviations), postoperative data (pain, nausea/vomiting, deviations, level of care) and date of death.
STATISTICAL ANALYSIS Descriptive statistics with univariable and multivariable analysis of associations. Candidate variables include sex, age, comorbidity, preoperative pain, anaesthesia type, procedure type, surgical technique and length of stay. The expected sample is approximately 70% of all bariatric operations in Sweden, about 3,000 patients per year; the main reason for exclusion is expected to be missing PACU registration of pain and/or nausea at some hospitals. As the study includes more than half of the target population, no formal power calculation is performed.
DATA PROTECTION Only pseudonymised data are handled. Data are stored at Umeå University with access restricted to the study researchers, in accordance with current legislation.
- Keywords
- PONV, postoperative pain, anaesthesia, total intravenous anaesthesia, regional anaesthesia, bariatric surgery, quality registry, SPOR, SOReg, RAND-36
- Medical subject headings
- Postoperative Nausea and Vomiting, Pain, Postoperative, Obesity, Morbid
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Adults undergoing primary bariatric surgery in Sweden 2018-2027 | Patients aged 18 years or older with a primary bariatric procedure registered in the Scandinavian Obesity Surgery Registry (SOReg) 2018-2027 and a matching operation record in the Swedish Perioperative Register (SPOR). |
What is being measured
The primary outcome is the main question the study is designed to answer.
Incidence of postoperative nausea and/or vomiting in the post-anaesthesia care unit
Number of operations with registered nausea and/or vomiting in the PACU divided by the total number of operations. Source: SPOR variable "Illamående postoperativt" (postoperative nausea).
Measured: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)
Pain intensity in the post-anaesthesia care unit, numerical rating scale (NRS) 0-10
Median NRS score (0 = no pain, 10 = worst imaginable pain). Source: SPOR variables "Smärta inom 1 tim efter ankomst UVA" (pain within 1 hour of PACU arrival) and "Smärta postoperativt, högsta" (highest postoperative pain).
Measured: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)
Incidence of severe pain in the post-anaesthesia care unit
Number of operations with NRS >= 7 divided by the total number of operations.
Measured: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)
Secondary outcomes (2)
Proportion of patients with postoperative complications, unplanned hospital care or reoperation - 6 weeks
Complications (including Clavien-Dindo grade), unplanned hospital care and reoperation as registered in SOReg at the 6-week follow-up.
Measured: Up to 6 weeks after surgery
Proportion of patients with postoperative complications, unplanned hospital care or reoperation - 1 year
Complications (including Clavien-Dindo grade), unplanned hospital care and reoperation as registered in SOReg at the 1-year follow-up.
Measured: Up to 1 year after surgery
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Sep 2026
- Study start1 Oct 2025
- Primary completion31 Dec 2027 (estimated)
- Study completionDec 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Postoperative Nausea and VomitingStudies of the same condition, open and under way.
- 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
- Observational
- Observational model
- Cohort
- Time perspective
- Retrospective
- Enrolment
- 30,000 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Umeå University
- Sponsor type
- University, hospital or other
- Collaborators
- Västernorrland County Council, Sweden, The Scandinavian Obesity Surgery Registry
- Responsible party
- Principal investigator, Jakob Walldén, Umeå University
- Investigators
- Jakob Walldén, MD, PhD, Principal investigator, Umeå University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07797374
- Sponsor's protocol ID
- BAROSPOR-2025-01
- Other IDs
- 2025-00877-01, 2025
- Acronym
- BAROSPOR
- Status last verified
- Aug 2026
- First submitted
- 27 Aug 2026
- Last updated
- 1 Sep 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 1 Sep 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Pain and Nausea in the Post-Anaesthesia Care Unit After Bariatric Surgery: A Registry Study Linking the Swedish Perioperative Register (SPOR) and the Scandinavian Obesity Surgery Registry (SOReg)
- ClinicalTrials.gov ID
- NCT07797374
- Acronym / sponsor ID
- BAROSPOR / BAROSPOR-2025-01
- Keywords
- PONV, postoperative pain, anaesthesia, total intravenous anaesthesia, regional anaesthesia, bariatric surgery, quality registry, SPOR
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 30,000 participants (estimated)
- Lead sponsor
- Umeå UniversityUniversity, hospital or other
- Collaborators
- Västernorrland County Council, Sweden, The Scandinavian Obesity Surgery Registry
- Study start
- 1 Oct 2025 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- Dec 2028 (estimated)
- First posted
- 1 Sep 2026 (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.
Around 4,000-5,000 bariatric (weight-loss) operations are performed in Sweden every year. Nausea, vomiting and pain are common immediately after these operations, cause considerable suffering and increase the intensity and length of hospital care. Bariatric surgery is one of the procedures with the highest risk of postoperative nausea and vomiting (PONV): about one third of patients experience PONV already in the recovery unit, and registry data indicate that around 40% report severe pain at the same stage.
This study links two national quality registries - the Swedish Perioperative Register (SPOR) and the Scandinavian Obesity Surgery Registry (SOReg) - to describe how often adult patients experience nausea, vomiting and pain in the post-anaesthesia care unit after primary bariatric surgery, and to identify patient, anaesthetic and surgical factors associated with these outcomes. The study tests whether total intravenous anaesthesia, the addition of a regional nerve block, and preoperative health-related quality of life are associated with PONV and pain, and whether early PONV or pain is associated with complications, unplanned hospital care or reoperation up to one year after surgery. The results are intended to show how well current evidence on preventing PONV and pain is applied in everyday practice and where care can be improved.
Detailed description
BACKGROUND Bariatric surgery is common in Sweden with 4,000-5,000 procedures per year. Data on each operation are recorded in the Swedish Perioperative Register (SPOR), covering more than 90% of all surgical procedures in Sweden with automatic data transfer from hospital IT systems, and in the Scandinavian Obesity Surgery Registry (SOReg), with a coverage of approximately 98% of bariatric surgery. Postoperative nausea and vomiting (PONV) and pain are frequent after bariatric surgery. Evidence-based guidelines exist, but 25-40% of surgical patients still experience PONV, and up to 50% may experience severe postoperative pain. Risk factors are validated at a general level but not specifically for bariatric surgery.
OBJECTIVES
- To describe the risk of early PONV and pain in the post-anaesthesia care unit (PACU) after primary bariatric surgery.
- To identify factors associated with early PONV and pain.
- To test the hypotheses that total intravenous anaesthesia (compared with inhalational anaesthesia) and the addition of a regional block are associated with lower risk of PONV or pain in the PACU; that poorer preoperative health-related quality of life (RAND-36) is associated with higher risk of PONV, pain and severe pain; and that PONV or pain in the PACU is associated with higher risk of postoperative complications up to one year after surgery. Separate hypothesis tests are performed for PONV and pain.
DESIGN Exploratory observational cohort study based on registry data. Patients aged 18 years or older with a primary bariatric procedure registered in SOReg during 2018-2027 are identified. Records are linked to SPOR by Uppsala Clinical Research Center (UCR) using personal identity number and date of surgery (+/- 3 days). If several SPOR records fall within the interval, each is included as a separate row with an index variable linking to the SOReg operation. Each individual is assigned a unique serial number and the dataset delivered to the research group contains pseudonymised data only. Data extractions are made at most once per year from 2025; the first analyses cover 2018-2023.
VARIABLES From SOReg: preoperative data (patient characteristics, comorbidity, laboratory values, preoperative work-up, RAND-36), operative data (procedure type, technique, intraoperative complications) and postoperative follow-up up to one year (complications, hospital care, reoperation). From SPOR: patient characteristics, process data, operative data (diagnosis, procedure, anaesthesia type, times, deviations), postoperative data (pain, nausea/vomiting, deviations, level of care) and date of death.
STATISTICAL ANALYSIS Descriptive statistics with univariable and multivariable analysis of associations. Candidate variables include sex, age, comorbidity, preoperative pain, anaesthesia type, procedure type, surgical technique and length of stay. The expected sample is approximately 70% of all bariatric operations in Sweden, about 3,000 patients per year; the main reason for exclusion is expected to be missing PACU registration of pain and/or nausea at some hospitals. As the study includes more than half of the target population, no formal power calculation is performed.
DATA PROTECTION Only pseudonymised data are handled. Data are stored at Umeå University with access restricted to the study researchers, in accordance with current legislation.
Study design
- Observational model
- Cohort
- Time perspective
- Retrospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Adults undergoing primary bariatric surgery in Sweden 2018-2027 | – | –Patients aged 18 years or older with a primary bariatric procedure registered in the Scandinavian Obesity Surgery Registry (SOReg) 2018-2027 and a matching operation record in the Swedish Perioperative Register (SPOR). |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
- Study population
- All adult patients registered in the Scandinavian Obesity Surgery Registry (SOReg) with a primary bariatric procedure during 2018-2027 and a matching operation record in the Swedish Perioperative Register (SPOR).
Key inclusion criteria (2 listed)
- Age 18 years or older
- Primary bariatric surgery registered in SOReg during 2018-2027
Key exclusion criteria (2 listed)
- Revision bariatric surgery
- If more than one bariatric operation is registered for the same patient, only the primary operation is included
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Incidence of postoperative nausea and/or vomiting in the post-anaesthesia care unit
Time frame: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)
Number of operations with registered nausea and/or vomiting in the PACU divided by the total number of operations. Source: SPOR variable "Illamående postoperativt" (postoperative nausea).
Pain intensity in the post-anaesthesia care unit, numerical rating scale (NRS) 0-10
Time frame: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)
Median NRS score (0 = no pain, 10 = worst imaginable pain). Source: SPOR variables "Smärta inom 1 tim efter ankomst UVA" (pain within 1 hour of PACU arrival) and "Smärta postoperativt, högsta" (highest postoperative pain).
Incidence of severe pain in the post-anaesthesia care unit
Time frame: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)
Number of operations with NRS >= 7 divided by the total number of operations.
2 secondary outcomes
Proportion of patients with postoperative complications, unplanned hospital care or reoperation - 6 weeks
Time frame: Up to 6 weeks after surgery
Proportion of patients with postoperative complications, unplanned hospital care or reoperation - 1 year
Time frame: Up to 1 year after surgery
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 Sep 2026.
- Swedish Perioperative Register (SPOR)Link provided by the sponsor.
- Scandinavian Obesity Surgery Registry (SOReg)Link provided by the sponsor.
- 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.
Jakob Walldén, MD, PhD principal investigator
Umeå University
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Postoperative Nausea and Vomiting and Postoperative Pain, run by Umeå University at 2 sites in Sweden.
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 2 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 Sep 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in Sweden. 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.
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 Jakob Walldén, MD, PhD (+46 60 14 52 55, jakob.wallden@umu.se), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Incidence of postoperative nausea and/or vomiting in the post-anaesthesia care unit (time frame: During the stay in the post-anaesthesia care unit (approximately 0-4 hours after surgery)). The study lists 3 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 1 Sep 2026; AzTrials last refreshed its copy on 26 Oct 2026.