An investigation of blood clots and other complications related to longer peripheral intravenous catheters in children

The primary outcome of the study is the frequency of midline catheter-related venous thrombosis in children receiving midline catheters at Astrid Lindgrens Children´s Hospital. 100 children receiving midline catheters at Astrid Lindgrens Children´s Hospital will be included in the study. The objectives of the study is primary to characterize the frequency of midline catheter-related venous thrombosis but also other possible complications in children receiving midline catheters at Astrid Lindgren Children´s Hospital. Patients will be followed for clinical signs of midline-related venous thrombosis as long as the catheter is in place. Ultrasonography will be used to detect asymptomatic venous thrombosis at the time of midline catheter removal. Patients that develop midline-related venous thrombosis will be followed until the end of treatment. Patients will be followed for other midline-related complications, such as infection, thrombophlebitis and mechanical complications. Life-span of midline catheter and the need for additional venous access to complete therapy will also be recorded. The total duration of observation per participant will be approximately 1-2 weeks.