Plethysmographic Variability index is a simple index accurate in predicting fluid responsiveness.

The aim of this study was to investigate its accuracy in predicting fluid response to intravenous fluid challenge during scoliosis surgery in children.

The goal of the present study is to assess the validity of PVI in predicting the response to a fluid challenge during scoliosis surgery in children.

During this observational non-interventional study, each fluid challenge will be monitored by esophageal Doppler and PVI (Massimo Radical 5).

Anesthesia, surgery and intraoperative fluid administration id standardized according to our clinical protocol.

An increase in indexed Stroke Volume (iSV) by more than 15 % will define the positive response to the fluid challenge.

Fluid challenges will be performed in the supine position and in the prone position.

Statistical analysis will performed using the Receiving Operator Characteristics (ROC) curve with determination of the gray-zone allowing an error tolerance of 10 %.

Inclusion Criteria:

• Scoliosis surgery
• Age < 18 years

Exclusion Criteria:

• Heart or vascular Diseases
• Rectal abnormalities
• Kidney Failure
• Neuromuscular scoliosis

Children undergoing scoliosis surgery