View clinical trials related to Acid Base Disorder.Filter by:
Study Title: The Impact of the pH on cardiac function in the critically ill patient Sponsor: King's College Hospital NHS Foundation Trust Chief Investigator: Dr Sancho Rodríguez-Villar IRAS Number: 227870 Hypothesis: Titration studies in animals with normal cardiac function show that a reduction in blood pH (and presumably that of the intracellular and interstitial compartments) from the normal level of 7.40 to 7.20 is associated with a rise in cardiac output. However, when blood pH is less than 7.20, cardiac output is reduced. Similar studies in humans with or without normal cardiac function have not been done, and yet blood pH at which aggressive treatment is recommended has been set at 7.20 based solely on animal experiments. The investigators hypothesize that a change in blood pH in humans will also affect cardiac function, but the level of blood pH at which this is observed might be similar or different in humans. In addition, the presence or absence of underlying cardiac disease and the type of acid-base abnormality present might modify the response of the heart to changes in blood pH. Primary Objectives: 1. Assess whether there are significant changes in cardiac function associated with changes in blood pH. 2. Relate the changes in cardiac function to the presence or absence of underlying cardiac disease. Study Design: A prospective multicenter observational study in 6 ICU´s (between two Trusts). During a year study period, a minimum of 300 patients will be recruited.
Blood gases are widely used in emergency and resuscitation services and are the key examination for exploring acid-base balance disorders (using pH, PaCO2 and HCO3 ) and gas exchange disorders (using PaO2 and PaCO2). This examination can be taken from both venous and arterial sample and its analysis depends on the type of blood sample. Currently, several studies have already shown the existence of a good correlation of pH and bicarbonates level between a venous and arterial sample. Thus, when this examination is prescribed for the purpose of highlighting and analyzing an acid-base disorder, venous blood gas is theoretically as efficient as arterial blood gas. Due to the lack of evidence of benefit for the patient or the health care team of a venous blood gas rather than an arterial blood gas in the absence of suspicion of hypoxemia, arterial blood gas is currently the standard of care for the analysis of acid-base disorders. Indeed, among the university hospitals affiliated to the Paris Diderot University, the emergency departments carry out in their vast majority (4 of 5 E.D.) arterial blood gases. Demonstration of the superiority of veinous sample over arterial sample regarding pain could substantially modify current practices. The investigator's main hypothesis is that, in the absence of suspicion of hypoxemia (normal oxygen saturation measured by plethysmography), the realization of a venous blood gas for the evaluation of the acid-base balance in the context of emergencies is less painful for patients, simpler for the health care team and provides sufficient biochemical information for the doctor in comparison with an arterial blood gas.
- The G coupled-protein receptors 99 (GPR99) was discovered in 2002 by Wittenberg et al. and is involved as a metabolic receptor. It has been shown that the natural ligand of GPR99 is an intermediate in the Krebs cycle, alpha-ketoglutarate (aKG). Studies done on rats have shown that aKG is measurable in the blood, freely filtered by the glomerulus and highly reabsorbed in the proximal tubule in metabolic acidosis, while it is not reabsorbed in metabolic alkalosis. No absorption or secretion of aKG intervene between the end of the proximal tubule and the final urine. Thus, having a receptor aKG in the distal tubule creates a paracrine communication with the proximal tubule, informing about the acid-base status of the body and allows adjustment of the urinary excretion of acid or base. - The hypothesis is that GPR99 is aKG sensor in the distal tubules and allow to report the acid-base status (determined by the metabolic activity of the proximal tubule) of the body to the distal tubule. This can then adapt the urinary excretion of acid or base in the final urine. Acidifying the body by a high meat consumption associated with a test of acidification, the kidney should reduce its aKG excretion and the concentration of this metabolite should be even lower in the urine. And vice versa in the case of alkalizing the body through a vegetarian diet associated with an alkalizing test. - Twelve healthy omnivorous volunteers will be selected. First inclusion visit includes verification of inclusion/exclusion criteria and signed informed consent. Urine and plasma baseline measurements will be performed and volunteers will meet a dietician. This person will tell them concerning meat and vegetarian diet as well as how to have a diet with 6g of salt per day.Volunteers are then randomized in order to determine which diet they will start first.The first phase will last during 4 days. The diet is followed during 3 days, and a 24-hour urine collection will begin on the third day at 7: 00 am. The fourth day, volunteers will have an investigational's day at the investigation's center after completing their urine collection at home (7:00 am). During the day of investigation, volunteers will give their urine (8: 00 am, corresponding to the baseline urine), and then the "meat" arm will receive a tablet of 50meq of NH4Cl and the "vegetarian" arm will receive a tablet of 1g of NaHC03. Volunteers will stay in the investigation center for 6h. Each hour since 8:00am, a urine sample will be taken, and at 3 hours and 6 hours post-tablet, a blood sample will also be made.This investigational's day will be followed by one to two weeks of treatment washing out. After that, the second phase will begin and will as the first phase excepted that the diet will be inversed. 5 other healthy vegetarian or vegan volunteers are recruited. Inclusion visit is the same as omnivorous volunteers. Only investigational's day at the investigation's center will be performed (no diet, no urine collection).