1. Failed spinal anaesthesia: mechanisms, management, and prevention
P.D.W. Fettes, J.-R. Jansson, J.A.W. Wildsmith 
British Journal of Anaesthesia 
Volume 102, Issue 6, Pages (June 2009)
DOI: /bja/aep096
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

2. Fig 1
Annual numbers of reports of failed spinal anaesthesia with bupivacaine received by AstraZeneca between January 1, 1993 and December 31, 2008 plotted according to region of the world.
British Journal of Anaesthesia  , DOI: ( /bja/aep096)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

3. Fig 2
Possible positions of the tip of a pencil-point needle. If it is correctly placed (upper picture) all of the local anaesthetic solution will reach the subarachnoid space, but if the opening ‘straddles’ the dura (lower picture) some solution will be deposited in the epidural space.
British Journal of Anaesthesia  , DOI: ( /bja/aep096)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions

4. Fig 3
To show how the dura or arachnoid mater may act as a ‘flap’ valve across the opening of a pencil point needle. During aspiration (a) the dura/arachnoid are pulled back allowing CSF to enter the needle. During injection the dura (b) or arachnoid (c) is pushed forward and the local anaesthetic enters the epidural or subdural space.
British Journal of Anaesthesia  , DOI: ( /bja/aep096)
Copyright © 2009 British Journal of Anaesthesia Terms and Conditions