experence of dry tap in spinal

[bhavin.shah]

hi, recently we have an experence of dry tap in spinal anesthesia. even after repeated attempts of spinal, we were not able to locate space. i can feel the resistence, but csf was not coming out. after few attempts, i gave spinal with bupivacaine after feeling resistence even though there was no csf (dry tap). surprisingly there was full effect of spinal.
   what can be the cause of it? does anybody have similar experince? 

[yogenbhatt1]

Yes, that is a funny and a blind thing to happen.
We have had another funny experience.
A full term patient was taken for em section. She was given a spinal block. For no reason she got a total spinal block with 5 % Lignocaon Heavy. ( Bupivacain was not still marketed). We managed the patient well and all was OK.
Incidentally the same patient came for her elective section in another hospital after 3 years. She informed about her past experience. It so turned out that the same anaesthesiologist was there and he recollected the event( A very remote thing to have same patient again in private practice in town like Mumbai)
This time she was informed that same thing may not happen again, it is incidental.
To our amazement she got a total spinal again.
Must be some anatomical defect in the spine.

[bhavin.shah]

there may be the chance of spinal canal stenosis. because of stenosis, xylocaine might have spread upwards. my senior collegue also had 2-3 experiences of dry tap and followed by good effect.

[anaesami]

dry tap followed by full effect could be due to coring of tissue in the needle which was probably pushed away by the force of injection. i have had dry taps but did not have the courage to inject the LA.