Inclusion Criteria:  Patients older than 18 yo, admitted to the Hospital Residencia Sant Camil Patients with at least one peripheral venous line for discontinuous treatment, which has not been channeled in a medical emergency situation. Written informed consent  Exclusion Criteria:  Allergy to heparin Patients treated with unfractionated sodium heparin. Patients in dialysis Patients with a venous catheter indicated for diagnosis tests. Patients with a venous catheter indicated for blood transfusion Severe heparin-induced thrombocytopenia in recent months Active uncontrollable bleeding during admission Brain aneurysm or dissecting aorta, except in association with corrective surgery. Confirmed / suspected cerebrovascular hemorrhage Severe uncontrolled hypertension Severe alterations in platelet coagulation <30,000, TP> 1.7 APTT ratio> 1.7 ratio. Patient included in another clinical trial with drugs or procedures that may affect the patency of venous catheters.