Assess the Potential of the IVC Distensibility Index as a Predictor of Postoperative Fluid Status in Children.

Preoperative settings:

Preoperative assessment will be done which includes Medical History and Clinical Examination: Age, gender, and weight will be recorded, Number of fasting hours, Surgical History documentation of previous surgeries, if any, including details on anesthetic techniques. family history of cardiovascular, renal, or fluid balance disorders. Information on any known allergies, particularly to medications, as well as a list of current medications being taken by the patient. Any coexisting medical conditions, particularly autoimmune, inflammatory, or chronic diseases, will be documented (e.g., asthma, diabetes, renal insufficiency).

Specific Examination for IVC Distensibility:

• Ultrasonographic Examination: Preoperative ultrasound will be used to measure the baseline Inferior Vena Cava (IVC) diameter and assess its distensibility as a part of the preoperative evaluation.

Preoperative Assessment of Fluid Balance:

• Laboratory Tests: Baseline blood tests, including complete blood count, serum electrolytes, and renal function tests, will be performed to assess overall fluid and electrolyte balance.

Intraoperative Monitoring:

Intraoperative fluid strategy will be followed with the local protocol 10 ml/kg/h will be given, and additional boluses 10-20 ml/kg if needed (in case of hemodynamic instability, increasing lactate), losses will be compensated with fluid or blood (if exceeded the allowable blood loss).

This fluid regimen is individualized by the attending anaesthesiologist according to the actual requirement, The volume of fluids administered intraoperatively will be meticulously recorded. Urine Output Documentation of baseline urine output as an indicator of renal function and fluid status.

Postoperative Settings:

All ultrasonographic measurments of IVC will be performed at the end of surgery, before extubation (patient is anaesthetized and completely relaxed, in the supine position, PEEP less than 7 cmH2O and tidal volume 6-8 ml/kg The probe will be placed at the sub xiphoid area and measurements will be obtained in M-mode imaging performed 2 to 3 cm distal to the right atrium in the long-axis subcostal view..IVC diameter during inspiration (IVCi) and expiration (IVCe) will be measured, Collapsibility index (CI) measured as difference between IVCe, IVCi divided on IVCe (CI = IVCe - IVCi /IVCe x100).

Inclusion criteria

• Pediatric patients aged 1-12 years.
• ASA status I - II
• Patients undergoing elective surgical procedures requiring general anesthesia.

Exclusion criteria

• Patients with known congenital heart disease, valvular heart disease or Pulmonary hypertension

• Renal disorders (Acute or Chronic).
• PEEP more than 7 cmH2O at time of assessment of IVC distensibility index