Yep, Jan and poodlebone, I know what you are talking about, I've had times I hit nerves too. Very painful.
This was on a different level... and to be honest I've never been bite by a snake so it might be nothing like it

. there was sudden intense pressure downwards into the skin relentlessly, and the time I was more awake and managed not to panic, as I said it took me over a minute to pry the line loose (turning the quickset release was like fighting against a pressure valve). I expect they will recall it, as it is exactly what would happen if the pump didn't stop pumping on an occlusion at the body end - intense pressure (think of a running garden hose into a sealed mouth!) which surely can't be good n healthy!