Dehydration | Hypohydration and Cardiorespiratory Function

Dehydration research study

What is the primary objective of this study?

Major non-cardiac surgery has a high degree of morbidity and mortality. Recently, measurement of a patient's preoperative cardiorespiratory reserve, performed non-invasively by cardiopulmonary exercise testing, has been shown to be predictive of outcome following non-cardiac surgery. All patients prior to major surgery are starved for a minimum of 6 hours and often longer prior to major elective surgery. It has been shown that elite athletes who are hypohydrated have reduced exercise capacity and lower cardiorespiratory function. These results are further exaggerated in \"non-trained\" individuals. Therefore, the starvation policy prior to surgery may have a deleterious effect on outcome after surgery. 4.2 AIMS This is a pilot study of health volunteers to assess the role of carbohydrate (CHO) (preload) and carbohydrate-protein (CHO-P) (Highfive energy source 1 in 4) in improving aerobic capacity after a period of fasting mimicking the current starvation policy prior to surgery. Both of these have similar calorific value and only differ in the amount of carbohydrate and protein supplementation.

Who is eligible to participate?

Inclusion Criteria: - Aged over 18 years - Volunteers with capacity to give informed consent - No underlying medical problems - Comprehension Of English Exclusion Criteria: - Volunteers who lack the ability to consent - Those unable to exercise - Those with contraindications to exercise testing (appendix A) - Diabetics - both insulin and non-insulin dependent diabetics due to the starvation period and carbohydrate load - Allergy to milk

Which medical condition, disease, disorder, syndrome, illness, or injury is researched?


Study Interventions

Interventions can include giving participants drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available or noninvasive approaches such as surveys, education, and interviews.

Dietary Supplement:CarbohydrateParticipants will be asked to drink an isotonic carbohydrate loaded drink (preload)night before the test and also two hours prior to the CPX test.

Dietary Supplement:Carbohydrate proteinParticipants will be asked to drink an isotonic carbohydrate drink (Highfive energy source 4:1)the night prior to the test and also two hours prior to the CPX test.

Dietary Supplement:StarvedParticipants will be asked to starve as per normal clinical requirements for surgery. They are allowed to drink water upto 2 hours prior to the CPX test

Study Arms

Research studies and clinical trials typically have two or more research arms. An arm is a group of people who receive the same treatment in the study.

CarbohydrateCHO loaded test:

Carbohydrate proteinCHO-P loaded test:

WaterStarved as for surgery

Study Status


Start Date: February 2014

Completed Date: July 2014

Phase: N/A

Type: Interventional


Primary Outcome: 1) To determine whether a period of starvation prior to exercise testing adversely affects cardiorespiratory reserve as assessed by cardiopulmonary exercise (CPX) testing

Secondary Outcome:

Study sponsors, principal investigator, and references

Principal Investigator: James Prentis, MBBS

Lead Sponsor: Newcastle-upon-Tyne Hospitals NHS Trust


More information:

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