Fluid replacement is considered the cornerstone of hemodynamic management in critically ill patients especially in patients with septic shock. However, only about 50% of critically ill hemodynamically unstable patients are responsive to fluids. Consequently, the resuscitation of critically ill patients requires an accurate assessment of the patients' intravascular volume status and their volume responsiveness. In this study, we will compare the efficacy of carotid artery flow to echo left ventricular end diastolic volume as a predictive value for fluid resuscitation in septic shock patients.

Fluid replacement is considered the cornerstone of hemodynamic management in critically ill patients especially in patients with septic shock. However, only about 50% of critically ill hemodynamically unstable patients are responsive to fluids. Consequently, the resuscitation of critically ill patients requires an accurate assessment of the patients' intravascular volume status and their volume responsiveness. In this study, we will compare the efficacy of carotid artery flow to echo left ventricular end diastolic volume as a predictive value for fluid resuscitation in septic shock patients.The Doppler study of carotid artery circulation (Velocity Time Integral, Peak Velocity) is simple and overpasses this common limitation among intensive care patients. Moreover, it showed to be an easy-learning tool The Velocity Time Integral (VTI) is a measurement of blood flow during systole that is passing through the left ventricular outflow tract (LVOT). The normal range for a VTI is 18-22 cm, values below this are suggestive of depressed cardiac output, an increase in the VTI is indicative of an increase in cardiac output. If a significant change in VTI 15% or more VTI0is observed after a fluid challenge, this would indicate that the patient is preload (fluid) responsive.

Inclusion Criteria:

• ▪ Age:18-50 years old

  • Sex: both males &females.

  • Patients diagnosed with septic shock according to SOFA score more than or equal 1

  • Presence of at least one sign of acute circulatory failure from:

    1. Low blood pressure (mean arterial pressure <65 mmHg and / or systolic <90 mmHg).
    2. Tachycardia> 120 bpm without other obvious cause of circulatory failure.
    3. Oliguria <1 ml / kg during the last hour suggestive of circulatory failure.
    4. Blood hyperlactatemia > 2mmol / l without other obvious cause a systemic circulatory failure.
    5. Another sign justifying, for example vascular increase capillary refill time more than 2 seconds.

Exclusion Criteria:

• ▪ Known significant valvular heart disease (sever aortic insufficiency or stenosis)

  • Known carotid artery stenosis >50% or previous carotid surgery
  • Clear contraindication to the carotid artery Doppler such as wound or infection or complete or partial occlusion of the carotid artery.
  • Arrhythmias affect stroke volume assessment (atrial fibrillation, frequent PVCs)
  • Dilated cardiomyopathy.
  • Poor transthoracic echocardiographic window
  • Patient refusal

septic shock patients in ICU