Anxiolysis and pain control are a duty for physicians and must be treated very carefully in the Pediatric Intensive Care Units, although it is very difficult to assess them: in critically ill children sedatives and/or analgesic medications are routinely provided and titrated to obtain a satisfactory level of sedation, but different evaluation scores are needed to discriminate between light or inadequate and deep or excessive sedation, especially when the clinical examination is unavailable. It is usual to associate a benzodiazepin with an opioid, more often Midazolam and Morphine or Fentanyl; other drugs as Propofol, Clonidine and Ketamine have specific indications, brief painful procedures and weaning from long periods of sedation to avoid withdrawal. Sometimes it can be useful to add a neuromuscular blocking agent to help mechanical ventilation. Adverse sedation events are relatively frequent, associated with drug overdoses and drug interactions, particularly when 3 or more drugs are used: all class of medications and all routes of administration are involved.