- Eight studies were identified which assessed thrombocytopenia or heparin-induced thrombocytopenia syndrome (HITS) in general surgery patients, orthopaedic surgery patients or cardiac surgery patients
- Six studies showed that the incidence of thrombocytopenia or HITS was lower in patients who received low molecular weight heparin (LMWH) compared to patients who received unfractionated heparin (UFH), regardless of type of surgery
- Only three studies confirmed the diagnosis of HITS by means of the presence of heparin-dependent antibodies
- Methodological limitations and small sample sizes of many of the studies identified limit the ability to determine the true incidence of HITS and time of onset
- Further research, examining HITS as a primary outcome, is required to elucidate the incidence of HITS with the use of unfractionated or low molecular weight heparin for the prophylaxis of venous thromboembolism