This is a randomized pilot study of therapeutic apheresis procedures (TAP) using the current standard of care catheter (SOC) vs the BD Nexiva Diffusics Catheter. It is a single blinded, randomized study. Data will be used to refine and power a full randomized control trial. For this study, a sample of 33 encounters in each group (total of 66 encounters). The specific aim is to test the hypothesis that the 20-gauge BD Nexiva Diffusics Catheter provides the same efficacy and lower pain level with no increase in adverse events for patients undergoing apheresis treatments.

TAP treats a wide range of disease processes and, in all cases, requires inlet and return venous access to perform the procedure. The goal of TAP is to return the patient to baseline and maintain independence and function. A larger needle (18 gauge) can cause more discomfort to the patient as well as additional scarring. A smaller needle may present less discomfort and scarring to the patient. The goal in the outpatient clinic is to minimize disruption to the patient's routine and help the patient maintain normal activities of daily living.

To accomplish these goals, the outpatient clinic is open Monday thru Friday offering 4 different appointment times. All patients that are referred to the clinic for TAP, first receive a vein evaluation to see if the patient is a candidate for peripheral IV therapy. At the clinic, approximately 68% of the patients TAP's are performed peripherally. This eliminates the risk of a central line infection and any alteration in activities of daily living, such as bathing(Kramer, 2016), (Shang, Ma, Poghosyan, Dowding, & Stone, 2014),(Keller et al., 2018; McDiarmid, 2015).

The hypothesis, is that the 20-gauge BD Nexiva Diffusics catheter provides the same efficacy as current practice with no increase in adverse events for patients undergoing therapeutic apheresis. The results from the study will be significant because if the 20 gauge needle is equally effective for TAP, it can increase the number of patients that would be candidates for peripheral therapy. Therefore, decreasing the need for central venous access, which place the patient at an increased risk of infection. The study is a comparison of 2 types of infusion catheters. The standard of care is an 18-gauge autogard catheter (control group) which will be compared to the 20-gauge BD Nexiva Diffusics (intervention).

P - patients who require therapeutic apheresis procedures (TAP) I - use of 20 guage (20G) BD diffusics catheter during apheresis C - use of 18 G standard of care IV catheter during apheresis O - no difference in efficacy and no increase in safety events

Inclusion Criteria:

• Adult (≥18 years old)
• Speaks and reads English
• A patient of the Apheresis clinic at University of Texas Southwestern University Hospital and Clinics
• Scheduled to receive TAP (therapeutic plasma exchange, red blood cell exchange and extracorporeal Photopheresis) as standard of care

Exclusion Criteria:

• Prisoners
• Persons under the age of 18 years
• Patient who are actively involved in chemotherapy

Due to the cross over study design, participants are represented as one Baseline group.

12 months

When the return rate is out of the SOC parameters the SOC apheresis equipment (Optia or Cellex) will alarm. If the alarm sounds 3 times the RN will decrease inlet rate by 5 ml/sec until the minimum threshold is reached (if needed), which is 50 ml/sec for plasma exchange and 35 ml/sec for RBC exchange and 20 ml/sec for photopheresis. If the alarm continues to when the minimum threshold is reached the catheter will be replaced with the SOC 18-gauge catheter.