We usually give heparin as routine thromboprophylaxis in the hospital. Our hospital has 88% of admitted patients on heparin. Very few are on lmwh. The risk is comparatively low. We excluded patients on lovenox from the study

Why is UFH used for thromboprophylaxis in your hospital when most of the research and guidelines recommend LMWH, except in case of patients with renal failure ?

Q8h dosing enabling us to hold when required, and mainly price i would say. ACCP recommendation is either of them.

One study in 2010 found HIT was reported in 1/272 patients in the LMWH group (0.4%, 95% CI 0.1 to 2.4) and in 4/289 in the UFH arm (1.4%, 95% CI 0.4 to 3.6). Lubenow, et al. Blood. 2010 Mar 4;115(9):1797-803.

In earlier work  by Levine et al  HIT was seen in 2/170 in the LMWH group (1.2%, 95% CI 0.2 to 3.8) and 10/192 in the UFH group (5.2%, 95% CI 2.7 to 9.1).Ann Intern Med. 1991 Apr 1;114(7):545-51.

Relative risk for HIT with LMWH compared with UFH  risk ratio (RR) 0.24, 95% CI 0.07 to 0.82; P = 0.02 in post surgical population meta analysis of those trials. Cochrane Database Syst Rev. 2012 Sep 12;(9) PMID: 22972111

In my experience the I see closer the Lubenow numbers for incidence (even lower in general internal medicine population). Seems clear risk for HIT is 3x or more with UFH than LMWH. We use LMWH as our standard and use UFH for those with high bleed risk ( UFH shorter half life & more fully reversible with protamine) or poor renal function (CrCl