Fluid Responseveness in Sepsis and Its Correlation to CVP

Study Overview
=================
Brief Summary
-----------------
Introduction Aim of the work Patients and methods Type of study Exclusion criteria Statistical analysis Research ethics Reference

Detailed Description
-----------------
Septic shock is a serious infectious condition characterized by low blood pressure and multiple organ damage. One of the traditional recommendations is to administer intravenous fluids as the first step to improve blood pressure(1). However, studies have shown that not every patient benefits from aggressive intravenous hydration (2). Previous studies have shown that certain parameters may correlate with volume status and others may not to correlate with patient volume status. Hemodynamic parameters, such as stroke volume variation (SVV) and pleth variability index (PVI) may better predict fluid responsiveness. However, assessments of these parameters require invasive procedures and special monitoring equipment, which limits their clinical application (4). Echocardiography has been widely adopted to diagnose and monitor cardiac dysfunction leading to hemodynamic instability, and shock pathophysiology in general. However, the echocardiographic information on macro-hemodynamics is partial, especially as being indirect as concerns vascular tone, and not allowing any inference on end-organ perfusion (5). Recently, ultrasonography for estimating volume status has been widely recommended because of its non-invasive nature, ease of acquisition, and reproducibility of measurements. The inferior vena cava (IVC) is a compliant vessel whose size and shape vary with changes in CVP and intravascular volume. Therefore, sonographic measurement of the IVC represents an effective and non-invasive method of estimating CVP. Respiratory variation in the IVC diameter was used as a guide for fluid therapy in septic shock in both spontaneous breathing and mechanically ventilated patients. Moreover, the assessment of visceral end-organ perfusion by ultrasound, may offer insights into this facet of shock pathophysiology (5). Among these ultrasound modalities, corrected flow time (FTc) measured in the carotid artery is a new approach for predicting fluid responsiveness that has shown promising results. Therefore, although it is a dynamic index, it may be able to adequately evaluate volume status in spontaneously and mechanically breathing patients. Aim of the work: 1- To evaluate whether carotid FTc as determined by Doppler ultrasound could be a predictor of fluid responsiveness in spontaneously breathing and mechanically ventilated patients. 2- To evaluate the predictive ability of ΔVpeak for fluid responsiveness in spontaneously breathing patients. 3- To detect changes of regional splanchnic hemodynamics by color Doppler resistive index, and its improvement after fluid administration. 4- To evaluate the predictive ability of IVC collapsibility and distensibility indices for fluid responsiveness in septic shock patients. 5- To compare between the predictive ability of the measured Ultrasonographic parameters and the CVP changes in response to intravenous fluid therapy in both spontaneously breathing and mechanically ventilated septic shock patients.

Official Title
-----------------
Ultrasonographic Predictors of Intravenous Fluid Responsiveness in Septic Shock and Its Correlation to Central Venous Pressure

Conditions
-----------------
Septic Shock

Intervention / Treatment
-----------------
* Device: US , Echocardiography


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: adult patients age≥18-year-old; written consent will be obtained. septic shocked patients show signs of acute circulatory failure at any time within the first 72 hours. Exclusion Criteria: Patients confirmed to have cardiogenic shock. History of heart failure or patient known to have moderate to severe valvular heart disease, congenital heart disease. The presence of carotid artery stenosis >50% , newly detected common carotid stenosis >50% during the study period. Non-sinus rhythm. Moderate to severe anemia. Markedly increased intraabdominal pressure as abdominal compartment syndrome, pregnancy. Medically diseased kidneys, ureteric obstruction peri-nephric collection.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
-----------------
All

Study Plan
=================
How is the study designed?
-----------------

Arms and Interventions

| Intervention/Treatment |
| --- |
|Device: US , Echocardiography|Carotid ultrasonography: Parameters will be measured by single blinded independent examiner using an ultrasound device. Baseline carotid FTc, ΔVpeak, will be measured. Echocardiography: Stroke Volume will be measured by transthoracic echocardiography. Renal and splenic Doppler resistivity index. Inferior vena cava collapsibility and distensibility indices. Central venous pressure estimation by central venous catheter, and central - Lung ultrasound for detection of lung congestion Lung ultrasound for detection of lung congestion.|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Ultrasonographic predictors of intravenous fluid responsiveness in septic shock and its correlation to central venous pressure | To evaluate whether carotid FTc as determined by Doppler ultrasound could be a predictor of fluid responsiveness in spontaneously breathing and MV patients. | Baseline | 
| Evaluation the predictive ability of ΔVpeak for fluid responsiveness in spontaneously breathing patients. | To evaluate the predictive ability of ΔVpeak for fluid responsiveness in spontaneously breathing patients. and the ΔVpeak will be calculated as follows: (maximum peak velocity - minimum peak velocity)/[(maximum peak velocity + minimum peak velocity)/2] × 100 | Baseline | 
| Detection changes of regional splanchnic hemodynamics by color Doppler resistive index, and its improvement after fluid administration. | To detect changes of regional splanchnic hemodynamics by color Doppler resistive index, and its improvement after fluid administration. Resistive index (RI): (peak systolic velocity - end-diastolic velocity) / peak systolic velocity. The normal range is 0.50-0.70. | Baseline |