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Trial registered on ANZCTR

Registration number

ACTRN12617000032358

Ethics application status

Approved

Date submitted

13/10/2016

Date registered

9/01/2017

Date last updated

9/01/2017

Type of registration

Prospectively registered

Titles & IDs

Public title

Assessing the influence of chewing gum on the gastric volume in patients fasting for surgery

Scientific title

Assessing the influence of chewing gum on the gastric volume in patients fasting for surgery

Secondary ID [1]

Nil Known

Universal Trial Number (UTN)

U1111-1187-5578

Trial acronym

Linked study record

Health condition

Health condition(s) or problem(s) studied:

Residual gastric fluid volume

Condition category

Condition code

Anaesthesiology

Anaesthetics

Oral and Gastrointestinal

Normal oral and gastrointestinal development and function

Intervention/exposure

Study type

Interventional

Description of intervention(s) / exposure

The intervention for assessment is pre-operative use of chewing gum outside of the usually applied fasting guidelines limits. Fasting otherwise will be six hours for food and two hours for clear fluids. Participants in the intervention group will be provided with Sugar-free mint flavoured chewing gum (posted out in a participant information pack) and given both verbal and written instructions on how it may be used. Verbal information will be provided by a research assistant, by phone and according to a scripted instruction pro-forma and at the time phone consent for participation is obtained. Written information will be included in the mailed participant pack. Instructions to participants will include to start chewing sugar-free chewing gum from the time of fasting from food. A packet of commonly used mint flavoured sugar-free gum will be sent out in the post with the study paperwork. Participants will be instructed to keep chewing gum right up until the nurses at Calvary Endoscopy to tell them to stop (when the nurses start preparing them for gastroscopy). Participants will be asked to take note of what time they start chewing the gum and how many pieces of gum are used out of the packet.

Intervention code [1]

Prevention

Comparator / control treatment

The control group will be asked to adhere to the usually applied fasting guidelines limits (six hours for food and two hours for clear fluids). Participants in the control group will be specifically instructed not to consume chewing gum.

Control group

Active

Outcomes

Primary outcome [1]

The primary outcome measure will be the proportion of cases with stomach aspiration volumes greater than 50ml, reflecting a clinically relevant threshold for risk of aspiration if such volumes were regurgitated during anaesthesia.

Timepoint [1]

Time of elective gastroscopy procedure

Secondary outcome [1]

Distribution of gastric content volumes: Both groups of patients will undergo their gastroscopy under a general anaesthetic. After insertion of the gastroscope the stomach will be inspected and then drained of any fluid by sucking it out through the suction channel of the gastroscope under direct vision by the gastroenterologist. The volume of the fluid sucked is then measured and recorded for each patient.

Timepoint [1]

Time of elective gastroscopy procedure

Secondary outcome [2]

Distribution of gastric content pH. The pH of the fluid sucked will be measured and recorded for each patient using a electronic fluid pH meter (testo 206 pH1 - pH meter for liquids, Testo Aus)

Timepoint [2]

Time of elective gastroscopy procedure

Eligibility

Key inclusion criteria

Adult patients aged greater than 18 years, who after being booked for an elective gastroscopy by their treating gastroenterologist at the specialist’s rooms, will be asked to take part in the trial.

Minimum age

18 Years

Maximum age

No limit

Sex

Both males and females

Can healthy volunteers participate?

Key exclusion criteria

i. Age less than 18 years
ii. Patient declines to be recruited as a participant in the trial
iii. Patient has a past history of upper gastrointestinal surgery including but not limited to : total or partial gastrectomy, operations involving gastroenterostomy (eg Whipples procedure), gastric lap band, laparoscopic sleeve gastrectomy, Nissen fundoplication, gastric pyeloplasty
iv. Past history of achalasia, severe oesophageal stricture, oesophageal carcinoma or other swallowing disorder
v. Past history of scleroderma or other disease causing gastroparesis
vi. Chronic oral opioid use or other medication causing delayed gastric emptying
vii. Patient deemed not competent to consent to the trial or competent to follow instructions required by the trial

Study design

Purpose of the study

Prevention

Allocation to intervention

Randomised controlled trial

Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)

Sealed opaque envelope

Methods used to generate the sequence in which subjects will be randomised (sequence generation)

Simple randomisation using a randomisation table created by computer software (i.e. computerised sequence generation)

Masking / blinding

Blinded (masking used)

Who is / are masked / blinded?

The people assessing the outcomes
The people analysing the results/data

Intervention assignment

Parallel

Other design features

Phase

Not Applicable

Type of endpoint/s

Safety

Statistical methods / analysis

The primary outcome measure (proportion of cases with stomach aspiration volumes greater than 50ml) would be estimated and compared using Poisson regression. Unadjusted and adjusted estimates would be made, with adjustment for potentially confounding variables: those variables would be selected from the measured demographic variables using backward stepwise regression.
Secondary outcome measures (distribution of gastric content volumes and pH) are expected to be strongly skewed distributions, so the two groups will be compared using ordered logistic regression (a rank-ordered test of distribution that allows adjustment for potentially confounding covariates). The distributions will be described as proportions of patients above a series of thresholds of increasing clinical risk (50ml, 75ml, 100ml etc) & (pH 4.0, 3.0, 2.5, 2.0 etc)

The sample size of 102 completed patients per group would be sufficient to detect a minimum absolute difference in the proportion of patients with a clinically relevant aspirated stomach volume of over 50ml of 10%, assuming that the proportion over 50ml in the control group is 2% with power 80% and P-value 0.05.

Recruitment

Recruitment status

Not yet recruiting

Date of first participant enrolment

Anticipated

1/02/2017

Actual

Date of last participant enrolment

Anticipated

1/07/2017

Actual

Date of last data collection

Anticipated

1/07/2018

Actual

Sample size

Target

204

Accrual to date

Final

Recruitment in Australia

Recruitment state(s)

TAS

Recruitment hospital [1]

Calvary Health Care Tasmania - Launceston campus - Launceston

Recruitment postcode(s) [1]

7250 - Launceston

Funding & Sponsors

Funding source category [1]

Charities/Societies/Foundations

Name [1]

Clifford Craig Medical Research Trust

Address [1]

W.D. Booth Centre, Launceston General Hospital, Charles St, Launceston TAS 7250

Country [1]

Australia

Primary sponsor type

Individual

Name

Gregg Best

Address

Principal investigator,

Country

Australia

Secondary sponsor category [1]

None

Name [1]

Address [1]

Country [1]

Ethics approval

Ethics application status

Approved

Ethics committee name [1]

Tasmanian Health and Medical Human Research Ethics Committee

Ethics committee address [1]

Ethics committee country [1]

Australia

Date submitted for ethics approval [1]

20/10/2016

Approval date [1]

16/12/2016

Ethics approval number [1]

H0016137

Summary

Brief summary

The need for a period of fasting (not eating or drinking) before having a general anaesthetic is well known and accepted by the community.  This measure is necessary to prevent patients from regurgitating and inhaling stomach contents, a phenomenon known as pulmonary aspiration.  Many people find fasting an unpleasant experience with hunger, thirst and dry mouth common complaints.  Some individuals find chewing gum while fasting helps with these symptoms, however, currently there is no significant medical evidence to either support or refute the safety of chewing gum in this period.

Our group proposes to conduct a study in patients who are booked by their gastroenterologist for a gastroscopy (an inspection of the inside of their stomach with a telescope).  We intend to randomly divide people into two groups, the first group will fast before their procedure as per the current normal instructions.  The second group will also fast, but will be asked to chew gum during their period of fasting before the endoscopy.  Both groups of patients will undergo their gastroscopy under a general anaesthetic.  After insertion of the telescope the stomach will be inspected and then drained of any fluid by sucking it out through the suction channel of the telescope under direct vision by the gastroenterologist.   It is normal for all people to a have a small volume (usually 20-30ml) of fluid in their stomach despite not eating or drinking due to swallowing saliva and the stomach producing its own secretions.   The volume of the fluid sucked is then measured and recorded for each patient.  The data collected during the course of the study will be collated and analysed statistically looking for any differences between the two study groups.  Once completed, the results of the study will be published in the medical literature.

The investigators postulate that chewing gum will make no significant difference in the amount of fluid in the stomach of a patient fasting before an operation. In fact, the action of chewing gum may actually be beneficial in stimulating the stomach to empty its normal residual volume of fluid.  The information gained from this study will be valuable to all anaesthetists in streamlining pre-operative fasting guidelines for their patients to ensure safety as well as potentially improving comfort while they are fasting.

Trial website

Trial related presentations / publications

Public notes

Contacts

Principal investigator

Name

Dr Gregg Best

Address

Department of Anaesthesia, Launceston General Hospital
Charles St, Launceston
Tas 7250

Country

Australia

Phone

+61 3 67776576

Fax

[email protected]

Contact person for public queries

Name

Gregg Best

Address

Department of Anaesthesia, Launceston General Hospital
Charles St, Launceston
Tas 7250

Country

Australia

Phone

+61 3 67776576

Fax

[email protected]

Contact person for scientific queries

Name

Gregg Best

Address

Department of Anaesthesia, Launceston General Hospital
Charles St, Launceston
Tas 7250

Country

Australia

Phone

+61 3 67776576

Fax

[email protected]

No information has been provided regarding IPD availability

What supporting documents are/will be available?

No Supporting Document Provided

Results publications and other study-related documents

Documents added manually

No documents have been uploaded by study researchers.

Documents added automatically

Source	Title	Year of Publication	DOI
Embase	Assessing the effect of sugar-free chewing gum use on the residual gastric volume of patients fasting for gastroscopy: A randomised controlled trial.	2019	https://dx.doi.org/10.1177/0310057X19886881

N.B. These documents automatically identified may not have been verified by the study sponsor.

Trial Review

Documents added manually

Documents added automatically