In children, only a few studies have compared different modes of propofol infusion during a total intravenous anesthesia (TIVA) with propofol and remifentanil. The aim of this study is to compare Bispectral Index (BIS) profiles (percentage of time spent at adequate BIS values) between four modes of propofol infusion: titration of the infusion rate on clinical signs (TIVA0), titration of the infusion rate on the BIS (TIVABIS), target controlled infusion (TCI) guided by the BIS either with the Kataria model (TCI KBIS) or the Schnider model (TCI SBIS).

Methods: Children will be prospectively randomized into the 4 groups. In the TIVA0 group the anesthesiologist is blinded to the BIS. In each group, the percentage of time with adequate BIS values (45-55), the bias and imprecision will be calculated.

Inclusion Criteria:

• weighting more than 15 kg;
• American Society of Anesthesiologists physical status I or II
• scheduled for middle ear surgery

Exclusion Criteria:

• cardiovascular, neurological, hepatic or renal impairment, if their body mass index was above 95th percentile or if they received any drug interfering with the central nervous system.