Abstract
Here we discuss the treatment of a post-lithotripsy, retroperitoneal haemorrhage using desmopressine (DDAVP) as monitored using closure time with a PFA-100 device. Five days after lithotripsy the patient's closure time reading (tested with the collagen plus epinephrine cartridge) normalized following DDAVP administration. This report demonstrates the usefulness of the PFA-100 in monitoring the treatment of platelet dysfunction and also evaluates possible contributory causes of this type of haemorrhage.