Difficulté de prédiction du bloc anesthésique de la péridurale et de la rachianesthésie : sources d'échec

Incomplete achievement of anaesthetic block after epidural or spinal anaesthesia may be a cause of failure. Patchy and restricted anaesthetic block or failure could be related to anatomical features such as CSF volume, spinal roots size, epidural septums dividing the epidural space, or Tarlov cyst. Age, weight, size, technical conditions and moreover pregnancy impair anaesthetic block distribution. Local anaesthetic solution parameters such as baricity have to be considered for prediction of anaesthetic block extension.