Results added knowledge on use of midline catheters (MCs) for blood sampling.
Using MCs for blood withdrawal resulted in low rates of hemolysis (0.69%).
Dwell time was longer in those who had blood drawn from their MC.
Nurse practices for blood sampling from MCs varied and learned from other nurses.
Background: Blood withdrawal from midline catheters (MCs) is done clinically, but no studies were found evaluating outcomes from this procedure, nor were clinical guidelines found. Drawing blood samples from short peripheral catheters is associated with higher hemolysis rates.
Methods: A prospective, observational, mixed methods study was used to evaluate outcomes from using MCs for blood withdrawal. Focus group sessions were held to evaluate nurses’ practices for this procedure.
Results: Data were collected over 3 months on 397 MCs in 378 patients. Hemolysis rates when the MC was used for blood withdrawal was 0.69% in 1021 tests. More than half had blood specimens drawn through the MC, and the time known for the successful withdrawal was on average 64 ± 85 hours. Mean dwell time for all MCs was 108.5 ± 98 hours, and when MCs were used for blood withdrawal, mean dwell time was 127.19 ± 109.13 hours and for MCs not used for blood withdrawal, 88.34 ± 79.86 hours (P < 0.001). In 338 patients who received therapy through their MC (n = 338), 87% completed intended therapy: 88% with blood withdrawal and 81% without blood withdrawal. Qualitative analysis from focus groups demonstrated wide variation in practice for blood sampling from MCs, and most learned techniques from their preceptors, other nurses, or patients.
Conclusions: Findings indicated that blood withdrawal from one specific type of MC had low rates of hemolysis, increased dwell time, and completion of therapy. More studies are needed to determine best practices for blood sampling through various types of MCs and outcomes.