It seems you can’t hang your hat on anything these days…including tachycardia in hypotension in the setting of intra-abdominal bleeding.
Apparently, the blood stimulates the vagus nerve. But it doesn’t have to be blood; Drs Doyle and Mark noted in 1990 the well-known phenomenon of bradycardia induced by manipulation of abdominal contents.
But that’s not all! Peritoneal dialysis can do it too!