For two decades desmopressin (DDAVP) has been used intravenously and more recently intranasally as therapy for von Willebrand disease (vWD) and qualitative platelet defects (QPD). However, which monitoring test(s) to employ following treatment is unclear. Bleeding time and plasma levels of von Willebrand factor and Factor VIII have generally been measured. Recently, the Platelet Function Analyzer-100(r) (PFA-100(r)) has been introduced to assess primary hemostasis in vitro to facilitate the diagnosis of vWD and QPD. The test is easy to perform and its results reproducible. It has also been successfully employed to assess the hemostatic response to intravenous DDAVP therapy. Little information is available, however, regarding the utility of the PFA-100 result (expressed as closure time using epinephrine and ADP-containing cartridges) as a measure of response to intranasal DDAVP. Therefore, we studied PFA-100 closure times before and 60-90 minutes after a 150-300 meg dose (depending upon weight) of DDAVP nasal spray in 7 children with vWD and 2 with a QPD, including 1 with Bernard-Soulier syndrome. Results were compared with pre- and post-ristocetin cofactor (R:CoF) results in the vWD patients. In all 9 évaluable children the epinephrine closure time declined from a prolonged pre-treatment value (median 248 sec; range 196 to > 300 sec; lower limit of normal 187 sec) to normal (median 110 sec; range 63 to 169 sec). R:CoF rose to normal in the 7 patients with vWD. In each case closure times using the ADP cartridge declined as well. Four of the 10 patients subsequently received intranasal DDAVP at the time of a minor surgical procedure and had no excessive bleeding. In conclusion, shortening of the PFA-100 closure time following intranasal DDAVP may represent a clinically relevant test confirming normal hemostasis in patients with vWD and QPD. Further study will be required to determine whether a normal PFA-100 closure time reliably assures adequate hemostasis during and following diverse surgical procedures.
|Original language||English (US)|
|Issue number||11 PART II|
|State||Published - Dec 1 2000|
ASJC Scopus subject areas
- Cell Biology