Clinical Trial: The Effect of Crystalloids and Colloids on Visceral Blood Flow
Study Status: Completed
Recruit Status: Completed
Study Type: Interventional
Official Title: The Effects of Balanced and Unbalanced Crystalloids and Colloids on Serum Biochemistry and Visceral Blood Flow: A Two Phase, Double Blind, Randomised Crossover Study
Brief Summary:
Patients often require fluid replacement during and after an operation. This is usually given through veins in the arm using an intravenous cannula and doctors have traditionally used fluid containing sodium chloride (saline). However accumulating evidence suggests that large infusions of saline are associated with adverse physiological effects including acidification of the blood and a rise in potassium and chloride levels. Studies in animals have shown that high levels of chloride in the blood and excess saline can cause blood vessels in the kidney to constrict leading possibly to a decrease in kidney function. Improvement in acid-base balance and kidney function may be observed with balanced solutions containing constituents that are more closely matched to the body's own fluid composition. However, little is known about the physiological effects of these solutions as they have only recently been developed.
Magnetic resonance imaging (MRI) is a radiological modality which can now assess blood flow and supply of the kidney noninvasively without the need for the injection of radiological dyes known as contrast agents. This is now of major importance due to the possible adverse effects of MRI contrast agents leading to Nephrogenic Systemic Fibrosis (NSF), a progressive disease which has been observed in some kidney patients after receiving 'gadolinium based' contrast agents. This has therefore led to increased interest and demand for noncontrast based imaging methods. In this study we aim to compare the effects of balanced versus unbalanced fluid infusions in healthy human volunteers:
We will aim to measure:
- Blood biochemical composition and acidity
- Kidney function and supply as measured by dynamic MRI
Detailed Summary:
Type of Study: Two phase double blind, randomised crossover study. In phase A (crystalloid), we will compare the effects of Plasmalyte 148 with 0.9% saline and in phase B (colloid) we will compare the effects of PVR with Voluven.
Participants will either be involved in phase A or phase B not both. In each phase participants will receive a randomly assigned fluid and then the comparator fluid 1 week later.
Subject selection: 24 healthy, male volunteers, (12 for each phase) between the age of 18 and 40, and weighing between 65 and 80 kg will be recruited for of the study. Informed consent will be obtained before entering volunteers into the study.
Study Protocol: Volunteers will report for the study at 09.00 hours after a fast from midnight and having abstained from alcohol, nicotine, tea and coffee for at least 24 hours. After voiding of the bladder, height will recorded to the nearest 0.01 m, weight measured to the nearest 0.1 kg using Avery 3306ABV scales (Avery Berkel, Royston, UK), and body mass index calculated.
Any urine passed over a 24 hour period from the start of the infusion will be collected for measurement of creatinine clearance, osmolality and electrolytes. Two venous cannulae will be inserted, one in each forearm and blood will be sampled for full blood count, haemoglobin, electrolytes, creatinine, albumin and osmolality. A venous blood gas sample will also be obtained to calculate base excess. Serum and urinary osmolality will be measured on a Fiske 2400 Osmometer (Vitech Scientific Ltd., Partridge Green, West Sussex, UK) using a freezing point depression method which has a coefficient of variance (CV) of 1.2%. A Vitros 950 analyser (Ortho Clinical Diagnostics, Amersham, UK) will be used to measure serum sodi
Sponsor: University of Nottingham
Current Primary Outcome: The primary end point of each phase of this study will be a 6 mmol difference in serum chloride concentration after infusion of the balanced and unbalanced crystalloids and colloids. [ Time Frame: Phase A: Times 0, 60, 90, 120, 180 and 240 min and Phase B: Times 0, 30, 60, 120, 180 and 240 min ]
Original Primary Outcome: Same as current
Current Secondary Outcome: Changes in blood volume, renal and superior mesenteric arterial blood flow and vessel diameter. [ Time Frame: Phase A: Times 0, 60, 90, 120, 180 and 240 min and Phase B: Times 0, 30, 60, 120, 180 and 240 min ]
Original Secondary Outcome: Same as current
Information By: University of Nottingham
Dates:
Date Received: March 15, 2010
Date Started: March 2010
Date Completion:
Last Updated: May 31, 2011
Last Verified: May 2011
