Unless they can pinpoint exactly where the leak is coming from I'm not sure a blood patch is an appropriate fix. I'm like the other respondent. I've had 2 patches resulting from spinal taps and they've worked, but they knew where to put the 'bandaid'.

I've had 5 and nothing.............2 were with glue & blood

I only had one once after a spinal headache due to a spinal tap. It worked instantly