Spinal induced hypotension is common complication in geriatric group of patient with percentage up to 73% among these group]. the most common causes that enhance occurrence of post spinal anesthesia induced hypotension among elderly are poor physical condition , chronic systemic diseases , medications and long fasting time, intraoperative hypotension if severe or prolonged is associated with hazardous complication such as myocardial infarction , stroke, renal failure and perioperative mortality ,so accurate assessment of intravascular volume before induction of anesthesia is necessary to limit these hazards.

Various studies had reported that ultrasonographic measurements of inferior vena cava collapsibility index is a good predictor for reflexing the intravascular volume status[5][6] , this is non invasive , on the other hand IVC is not easily feasible in obese and pregnant women.

Some studies compared the difference between IVC and IJV as predictor marker for fluid responsiveness and reported that right internal jugular vein distensibility appears to be a surrogate marker for inferior vena cava vein distensibility for evaluating fluid responsiveness.

Almost great percentage of anesthesiologist easily use IJV ultrasonography for catheterization and it is easily feasible in almost all patients, recent studies documented that noninvasive ultrasonographic measurements of internal jagular vein diameter has a role in assessment of intravascular volume status in spontaneously and mechanically breathing patients, Passive leg raising has been shown to be useful in assessing intravascular volume depletion or fluid responsiveness , some studies compared IJV changing in diameter for supine and trendelenburg positions, there is a similar change in IJV diameter will occur with passive leg raising positions , trendelenburg position may be disadvantageous as it impair gas function and cardiac function especially in elderly and obese patients , on the other hand passive leg raising is simpler and more comfortable to the elderly.

Finally preoperative detection of decreased intravascular volume is crucial in elderly patients, so we hypothesized that preoperative ultrasonographic evaluation of the internal jagular vein measurements may be a reliable tool for estimating intravascular volume and prediction of post spinal hypotension in elderly.

Inclusion Criteria:

• • Age > 65 years old.

  • Both sexes.
  • American Society of Anesthesiologists (ASA) physical status I, II , III.
  • Elective surgeries Under spinal anesthesia in the supine position.

Exclusion Criteria:

• • Body Mass Index (BMI) more than 35 kg/m2.

  • Uncontrolled hypertension.
  • Ejection fraction less than 40%
  • Emergency cases.
  • Absolute or relative contraindications to spinal anesthesia.
  • Patients with a baseline arterial systolic blood pressure (SBP) less than 90 mmHg or mean arterial blood pressure (MBP) less than 65 mmHg.

elderly patients equal or more than 65 years old