PTT monitoring


The scenario '' Pt is on heparin therapy for DVT treatment. Last PTT 102 ''

Question: Is this PTT a normal therapeutic range? The literature provides different answers. I am confused. Can you tell me what the range should be.

According to my book aPTT = 20-39 Therapeutic range 1.5 - 2.5 normal.


132 Posts

Our hospital has a heparin protocol - docs can order a drip by protocol where we can adjust based on PTTs or order without protocol in which we give them the results and they order a new dosage.

In any case the pt should have a baseline PTT for comparison. By our protocol we stop the drip for an hour for a PTT over 100, then restart at a specified lower dose and recheck PTT 6 hours later.


81 Posts

Thank you. It was helpful information to know.


64 Posts

Specializes in Telemetry, ICU/CCU, Specials, CM/DM. Has 14 years experience.

At my facility that I used to work at, the protocol for therapeutic was 70-90. Some doctors wrote their own parameters. Every facility may be different, so check your facility for their protocol and P&P. 102 would definitely be high and we did also stop the infusion for one hour also. Good luck!