Improving Apheresis Inlet Flow With a Novel Double-Draw Vascular Access Technique

Peripheral intravenous catheters (PIVCs) are the preferred vascular access for apheresis; however, veins that initially appear suitable may develop venous spasms, resulting in poor inlet flow and frequent pressure alarms. Ports used for apheresis can also experience inlet pressure alarms due to catheter or venous occlusion. When conservative measures failed, we implemented a novel double-draw technique in which a second draw line was connected via a four-way stopcock and male-to-male adapter to the initial draw access (either a PIVC or port) to improve inlet flow. The double-draw technique was performed in 26 procedures (therapeutic plasma exchange [TPE], n = 10 and lipoprotein apheresis [LA], n = 16) in 8 patients. During TPE, median negative inlet pressure improved from -179 mmHg (IQR -218 to -69) with single-draw access to -71 mmHg (IQR -78 to -62) following placement of a second draw line (p = 0.0162). Inlet flow rate during TPE improved from median 47 mL/min (IQR, 40-58 mL/min) with single-draw access to 70 mL/min (IQR, 60-75 mL/min) (p = 0.008). During LA, median negative inlet pressure improved from -136 mmHg (IQR -193 to -109) to -59 mmHg (IQR -66 to -47) (p < 0.0001). Median inlet flow rate during LA improved from 70 mL/min (IQR 59-71 mL/min) with single-draw access to median 80 mL/min (IQR 70-80 mL/min) (p = 0.023). Overall 25 of 26 procedures (96.2%) demonstrated an improvement in inlet pressure following implementation of the double-draw technique. All procedures were completed successfully without abandonment of the original access site. The double-draw technique is a novel option for managing inlet pressure alarms during apheresis when conservative measures fail.