Incidence of Deep Vein Thrombosis in Restrained Psychiatric Patients

BackgroundAlthough physical restraint is still used in psychiatric inpatient settings, it sometimes causes serious side effects, including deep vein thrombosis (DVT) and resulting pulmonary embolism.ObjectiveThe aim of this study was to investigate the incidence of the DVT in restrained patients who were receiving routine prophylaxis and to identify the risk factors of this condition.MethodsThis study was conducted at Sakuragaoka Memorial Hospital, Japan from December 2008 to September 2010. Inpatients who were restrained during the study period were included. All restrained patients wore graduated compression stockings and were recommended to receive subcutaneous injection of unfractionated heparin during the period of restraint unless it was contraindicated. When plasma d-dimer level at the time of removal of restraint was ≥ 0.50 μg/dL, the patients underwent a Doppler ultrasound scanning of their lower extremities to examine the presence of DVT. A multiple logistic regression model was used to examine the effects of demographic and clinical characteristics on the incidence of DVT.ResultsA total of 181 patients (98 men; mean ± standard deviation age, 47.8 ± 17.0 y) were included; DVT was detected in 21 patients (11.6%). A longer duration of restraint (odds ratio = 9.77, 95% confidence interval = 1.56–61.03, p = 0.015), excessive sedation (odds ratio = 4.90, 95% confidence interval = 1.33–18.02, p = 0.017), lower antipsychotic dosage (odds ratio = 0.05, 95% confidence interval = 0.005–0.57, p = 0.016), and recent medical hospitalization (odds ratio = 11.44, 95% confidence interval = 2.13–61.47, p = 0.004) were significantly associated with the incidence of DVT.ConclusionThe incidence of DVT in restrained psychiatric patients was not low in spite of prophylaxis. These findings emphasize the importance of regular screening of and thorough assessments of DVT, especially in restrained psychiatric patients.