A comparison of stomach volume in volunteers following two different guidelines for starvation before a general anaesthetic
| ISRCTN | ISRCTN17470442 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN17470442 |
| IRAS number | 238262 |
| Secondary identifying numbers | 49141, IRAS 238262 |
- Submission date
- 21/07/2022
- Registration date
- 25/07/2022
- Last edited
- 20/01/2023
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
According to current UK guidelines, people are asked to avoid drinking clear fluids for 2 hours before an operation (and to avoid solid food for 6 hours before). This is to make sure that their stomach is empty at the time of their operation because it can be dangerous if the stomach is not empty. However, it has been suggested that people should be allowed to drink clear fluids closer to the time of their operation because water leaves the stomach quickly. This could reduce the risk of someone becoming dehydrated, and reduce the likelihood of experiencing symptoms of thirst, dizziness, headache or nausea. Often a delay in the start of surgery can lead to extended periods of fasting. Some countries are already following less strict guidelines than the UK. The aim of this study is to measure how quickly a drink of water leaves the stomach of healthy people, and how much is left in the stomach after following the UK fasting guidelines and the less strict Scandinavian guidelines.
Who can participate?
Healthy volunteers aged over 18 years
What does the study involve?
Participants will be asked to fast from food for 6 hours and water for 2 hours, and then attend the Musculoskeletal Research Unit for an ultrasound examination of their stomach. In order to locate the stomach, an ultrasound probe will need to be placed on the skin around the abdomen. Therefore, it is important that suitable clothing is worn (i.e. easy to expose the abdomen). The researchers will take some basic details and then perform an ultrasound scan of the stomach. This will give us a baseline value of the area of the stomach after a period of fasting. Following this, participants will either be designated to follow a protocol of having drinks of water over a period of 2 hours, or to have no drinks at all. At various points the researchers will perform additional ultrasound scans. Participants will be asked to provide ratings of their comfort, thirst, hunger and anxiety levels at various timepoints during the session. Following the scans participants can eat and drink immediately. Participants attend on two separate days so the researchers can repeat the study with different amounts of water during the ultrasound examination.
What are the possible benefits and risks of participating?
There will not be any direct benefits to participants, but there may be potential benefits to those undergoing surgery in the future. There are no major risks of being involved. The study will only require participants to undergo a period of fasting, to drink water at set intervals and to undergo ultrasound scans. They may feel thirsty or uncomfortable during the fasting period, although the times will be kept as short as possible. Someone will monitor participants' comfort levels at all times and should they wish to stop participating they may do so at any time. Ultrasound scanning has been shown to be one of the safest medical techniques and is routinely used to scan babies, both before and after birth, children and adults. It has been widely used in clinical practice for over 40 years, providing valuable pictures and information with no evidence of any harm. However, just as ordinary sounds that are too loud can damage hearing, very high levels of ultrasound can produce undesirable effects, for example by warming the tissue through which the ultrasound passes. Because of this there are strict guidelines about the level of ultrasound that can be used. This study will operate well within these guidelines.
Where is the study run from?
The Musculoskeletal Research Unit at the University of Bristol (UK)
When is the study starting and how long is it expected to run for?
January 2015 to September 2018
Who is funding the study?
David Telling Charitable Trust (UK)
Who is the main contact?
Dr Chris Thompson, at17585@bristol.ac.uk
Contact information
Principal Investigator
Southmead Hospital
Westbury-on-Trym
Bristol
BS10 5NB
United Kingdom
 ORCID ID |
0000-0002-2058-8388 |
|---|---|
| Phone | +44 (0)1179505050 |
| christopher.thompson@nbt.nhs.uk |
Public
Southmead Hospital
Westbury-on-Trym
Bristol
BS10 5NB
United Kingdom
| ORCID ID |
0000-0002-2058-8388 |
|---|---|
| Phone | +44 (0)1179505050 |
| christopher.thompson@nbt.nhs.uk |
Scientific
Southmead Hospital
Westbury-on-Trym
Bristol
BS10 5NB
United Kingdom
| ORCID ID |
0000-0002-2058-8388 |
|---|---|
| Phone | +44 (0)1179505050 |
| christopher.thompson@nbt.nhs.uk |
Study information
| Study design | Single-centre interventional single-blinded randomized controlled trial |
|---|---|
| Primary study design | Interventional |
| Secondary study design | Randomised controlled trial |
| Study setting(s) | Other |
| Study type | Prevention |
| Participant information sheet | 42112_PIS_V1_14Feb17.pdf |
| Scientific title | A randomised trial of ultrasonographic assessment of gastric emptying following water ingestion in healthy volunteers |
| Study objectives | It is hypothesised that water leaves the stomach rapidly and that ultrasound can be used to assess this when healthy volunteers have followed either current UK guidelines for fasting before anaesthesia, or a more liberal fluid regime (Scandinavian guidelines). |
| Ethics approval(s) | Approved 03/05/2017, University of Bristol Faculty of Health Sciences Research Ethics Committee (University of Bristol Faculty of Health Sciences, First Floor South, Senate House, Tyndall Avenue, Bristol, BS8 1TH, UK; +44 (0)117 331 8197, +44 (0)117 928 9089; Liam.McKervey@bristol.ac.uk), ref: 49141 |
| Health condition(s) or problem(s) studied | Gastric volume after following two different guidelines for starvation prior to general anaesthetic |
| Intervention | Participants are allowed clear fluids but no solid food for the first 4 hours of the study, and for the next 2 hours before the theoretical time of induction of anaesthesia (time zero) they are randomised to either a nil-by-mouth ‘control’ group or an ‘H₂O’ group (150 ml of water each hour). Participants are randomised by opening sequential envelopes. Gastric volume is measured by ultrasound every 30 minutes during the 2-hour study period in which participants were at the study location, with measurements taken both immediately before and after intervention (either consuming water or remaining fasted). A minimum of seven measurements are made. In the event that gastric volume has not returned to baseline volume by the end of each protocol further ultrasound scans are conducted for up to an additional 2 hours. Ultrasound scans are performed by four qualified NHS sonographers (PG Diploma - Medical Ultrasound) trained in gastric ultrasound using a Sonosite X-Porte ultrasound machine with a curvilinear 2-5 MHz probe (FUJIFILM Sonosite Limited, UK). Assessment of gastric volume is made by measuring the gastric antral cross-sectional area (CSA) using the method described on https://www.gastricultrasound.org, with permission from the authors. Scanning is performed with the participant in the right lateral decubitus position, with minimal probe pressure and images acquired at the end of normal tidal volume expiration. The cross-sectional area of the antrum is calculated by the sonographer using a free-hand tracing technique. Gastric volume is calculated as follows: Gastric Volume (ml) = 27.0 + 14.6 x right-lateral CSA (cm²) – 1.28 x age (yr) |
| Intervention type | Other |
| Primary outcome measure | Total gastric volume at time zero. Gastric volume is measured by ultrasound every 30 minutes during the 2-hour study period in which participants were at the study location, with measurements taken both immediately before and after intervention (either consuming water or remaining fasted). A minimum of seven measurements are made. In the event that gastric volume has not returned to baseline volume by the end of each protocol further ultrasound scans are conducted for up to an additional 2 hours. |
| Secondary outcome measures | Wellbeing scores: quantitative data on thirst, hunger and anxiety scores collected using a simple numeric interval scale of 1 to 10 developed for this study at t-120, t-60 and t0 |
| Overall study start date | 06/01/2015 |
| Completion date | 29/09/2018 |
Eligibility
| Participant type(s) | Healthy volunteer |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Sex | Both |
| Target number of participants | 15 |
| Total final enrolment | 15 |
| Key inclusion criteria | 1. Adults aged 18 years or over 2. Able to follow the protocol 3. Able to attend on two separate days |
| Key exclusion criteria | 1. Pregnancy 2. Taking medication that may influence appetite or gastric physiology 3. Any medical condition which alters appetite or gastric physiology, e.g. previous gastro-duodenal surgery 4. Diabetes mellitus 5. Advanced liver or renal disease 6. Recent gastrointestinal infection (within 1 month) 7. Any condition that hinders the acquisition of ultrasound images |
| Date of first enrolment | 26/05/2018 |
| Date of final enrolment | 29/09/2018 |
Locations
Countries of recruitment
- England
- United Kingdom
Study participating centre
Southmead Hospital
Westbury-on-Trym
Bristol
BS10 5NB
United Kingdom
Sponsor information
University/education
Research and Enterprise Division
2nd Floor, Augustine's Courtyard
Orchard Lane
Bristol
BS1 5DS
England
United Kingdom
| Phone | +44 (0)1174552198 |
|---|---|
| red-office@bristol.ac.uk | |
| Website | https://www.bristol.ac.uk/red/about/ |
"ROR" |
https://ror.org/0524sp257 |
Funders
Funder type
Charity
Private sector organisation / Trusts, charities, foundations (both public and private)
- Alternative name(s)
- THE DAVID TELLING CHARITABLE TRUST
- Location
- United Kingdom
Results and Publications
| Intention to publish date | 01/10/2022 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Stored in publicly available repository |
| Publication and dissemination plan | Planned publication in a high-impact peer-reviewed journal |
| IPD sharing plan | The anonymised data are available at the University of Bristol data repository (data.bris) at https://doi.org/10.5523/bris.10ejjx7clm1x728dw0w5xxcydy. Further information is available at https://www.bristol.ac.uk/staff/researchers/data/ |
Study outputs
| Output type | Details | Date created | Date added | Peer reviewed? | Patient-facing? |
|---|---|---|---|---|---|
| Dataset | 13/08/2020 | 25/07/2022 | No | No | |
| Participant information sheet | version 1 | 14/02/2017 | 25/07/2022 | No | Yes |
| Protocol file | version 6 | 01/02/2017 | 15/08/2022 | No | No |
| Preprint results | 26/07/2022 | 20/01/2023 | No | No |
Additional files
Editorial Notes
20/01/2023: Preprint reference added.
15/08/2022: Protocol file uploaded.
25/07/2022: Trial's existence confirmed by the David Telling Charitable Trust.
