View clinical trials related to Hypovolemia.
Filter by:The purpose with the planned study is to study Pleth Variability Index (PVI) as a non invasive indicator for mild hypovolemia during spontaneous breathing in healthy subjects. Lower body negative pressure (LBNP), a well established technique is used to create defined levels of hypovolemia. Primary hypothesis: By applying a breathing resistance (positive end expiratory pressure PEEP) to spontaneous breathing, the respiratory synchronous variation in the pulse oximeter signal (PVI) is enhanced and enables PVI to detect and grade the level of mild hypovolemia. Secondary hypothesis: 1) When tidal volume is increased, the respiratory synchronous variation in the pulse oximeter signal (PVI) will also increase. 2) The earlobe is superior to the finger in detecting PVI 3) Hemoglobin (Hb), detected non invasively by pulse oximetry, is not affected by hypovolemia created by LBNP
The primary objective of this study is to demonstrate that preoperative fasting does not increase the rate of lowered blood volume (defined by a variation of 15% ΔITV during a leg lift) in patients undergoing surgery.
In the prehospital setting it would be helpful to assess primary changes in central blood volume or preload (venous return, stroke volume, diastolic ventricular volume) that occur during the stability phase following injury when regulatory mechanisms are still functioning. Obviously in this setting a non invasive bedside beat-to-beat index would be helpful. Pulse Transit Time (PTT) is the sum of Pre-Ejection Period (PEP), the time interval between the onset of ventricular depolarization and the ventricular ejection, and Vascular Transit Time (VTT), the time it takes for the pulse wave to travel from the aortic valve to the peripheral arteries (Obrist et al. 1979). PEP variations are known to correlate with reductions in central blood volume induced by head-up tilt (Chan et al., 2007b, 2008). The same authors also demonstrated that PTT variations follow closely PEP variations and therefore central blood volume variations (Chan et al., 2007b). Following central blood volume reductions induced by head-up tilting ventricular diastolic filling time increases involving an increase in PEP and PTT. Chan et al. (Chan et al., 2007b) concluded that PTT could have been used to assess early central hypovolemia and suggested that joint analysis of PTT and RR intervals could help in predicting the extent of blood volume loss. The investigators hypothesized that sympathetic drive associated with trauma would act on cardiac contractility through beta activity thus shortening PTT without reducing RR interval to the same extent in healthy hearts. We also hypothesized that progressive hypovolemia would lead to a rising of PTT (augmented diastolic filling time) and a RR interval shortening (relative tachycardia). In this study the investigators propose and index based on the beat-to-beat PTT/RR ratio to assess central hypovolemia in traumatic patients enrolled by our Helicopter Emergency Medical System (HEMS) in a prehospital setting.
The study shall evaluate the volume effect and safety of 6 % hydroxyethyl starch 130/0.4 for restoration and maintenance of hemodynamics during the investigational period in patients undergoing major elective surgery. Up to 50 mL 6% hydroxyethyl starch/kg body weight will be administered from start of surgery until two hours after end of surgery. The study hypothesis is that 6 % hydroxyethyl starch 130/0.4 will have a reliable volume effect and can be safely administered up to the dose limit.
The study shall evaluate the efficacy and safety of two different hydroxyethyl starch solutions (artificial colloids 6% HES130/0.4 and 6% HES70/0.5, Salinhes®) for intra-operative therapy of hypovolemia and maintenance of circulating blood volume in patients undergoing orthopedic surgery. The primary efficacy endpoint will be the required volume of colloid solution infused from start until end of surgery. It is the aim of the clinical trial to demonstrate that comparable volumes of colloid solution are used between treatment groups.
Postoperative organ dysfunction severely affects the prognosis of surgical patients. Despite several trials evaluating restrictive or liberal fluid strategies, the ideal fluid replacement strategy remains controversial. Owing to the risk of altered tissue perfusion, a key trigger of organ dysfunction, the purpose of this study was to compare the influence of restrictive and liberal fluid regimens, using a goal-directed approach, on hypovolemia and postoperative organ dysfunction.
The purpose of this study is to examine how the heart functions when a calculated amount of blood is removed and how two fluids, Lactated Ringer's (considered the standard replacement fluid) and Hypertonic Saline, re-expand the vascular system.
This study proposes to examine the correlation of central venous pressure to measures of the diameter of the inferior vena cava as determined by bedside ultrasonography.
The effect of individualized fluid optimization during neuroaxial blockade has not been evaluated. The investigators evaluated if if Stroke decrease 15 min after activation of neuroaxial blockade and whether SV could be optimized to pre activation values.
It is the purpose of the researchers to identify the variation in intravascular deficits which can have relevance in high risk patients for minor and medium sized surgery. The investigators will also estimate fluid deficit in healthy, non-fasting subjects for comparison.