Effect of Oral Water on the Quality of Volume Expansion in Resuscitation Patients (WATER)

In ICU and operating theatre, fluid expansion is the main hemodynamic therapeutic. The objective of fluid expansion is to increase cardiac output thus arterial oxygen delivery to match patient's oxygen consumption. To date, it has been shown that all fluid expansion solutions may have side effects (hydro-electrolytic disorder, renal failure, hydro-sodium overload, etc.) that may limit their use.

Human digestive system physiologically ensures the absorption of oral water and hydration of the human body. Water is quickly absorbed by the digestive tract with a peak between 15 and 20 minutes. It has demonstrated that oral water remains the best hydration solution that have an effect on plasma volume expansion and cardiovascular system during exercise. While the cardiovascular effect of fluid expansion by saline serum is well known (venous return, preload and cardiac output), that of oral water vary in the literature depending on the physiological state of the patient and the clinical state. Oral water can change cardiac output and blood pressure through various physiological effects: increased blood volume, recruitment of splanchnic blood volume, and peripheral vasoconstriction. Usually, ICU patients have feeding through nasogastric tube.

To date, no study has studied the effect of a given amount of enteral cardiovascular system in ICU patients. The objective of this study is to describe the effect of oral water administration on the cardiovascular system of patients during the optimization and/or hemodynamic stabilization phase. The comparison of groups (water/ physiological saline) would allow us: (1) to describe the cardiovascular effects of water in the resuscitation patient, (2) to compare these cardiovascular effects with those of saline solution, (3) to have the data to design further study.