Systemic hypotension in anaesthetised neonates, infants and children: beyond blood pressure thresholds-practical considerations.

This technical note is meant to be complementary to the recently published Professional Practice Guidelines of the SFAR-ADARPEF. The limits of using blood pressure as a surrogate for changes in cardiac output and the variable accuracy of its non-invasive measurement are reminded. As clearcut population-based threshold values based on measurements obtained in awake or anaesthetised children cannot be provided, an adaptation based on the child's baseline blood pressure, comorbidity and surgical context is necessary to prevent unnecessary treatment of an acceptable low blood pressure or tolerating a too low blood pressure. The measurement of a baseline awake blood pressure, although often difficult to achieve in children, is therefore very helpful. If a low intraoperative MAP is measured, the presence of hypotension should be confirmed by repeat measurement and the simultaneous evaluation of clinical and paraclinical signs, and the observation of the surgical field. The treatment should then be adapted to the cause: anaesthetic overdose, hypovolaemia, positioning, surgical action, anaphylaxis, etc.