Pulmonary artery catheter introducers: do the component parts affect flow rate?

Arrow sheath introducers are useful during massive transfusion as well as during catheter insertion. However, each component (sheath, side port, and obturator/catheter) probably progressively impedes maximum flow. This study quantitates these flow changes. Six configurations (C) were tested: (C1) sheath; (C2) sheath, side port; (C3) sheath, side port, obturator; (C4) C3 with 1.5-in obturator; (C5) C3 with 0.25-in obturator; (C6) no components. Flow was measured five times with each configuration and compared. Flows (mL/min) (mean +/- SE) were: (C1) 838.1 +/- 11.2, (C2) 283.4 +/- 9.2, (C3) 149.9 +/- 7.9, (C4) 176.0 +/- 14.0, (C5) 232.5 +/- 5.5, (C6) 1030.5 +/- 11.6. Flow decreased progressively with C2 and C3 (P less than 0.0001). C4 did not increase flow, but C5 did (P less than 0.0001). C5 flow was comparable to C2 but less than C1 (P less than 0.0001). C6 flow was larger than any other configuration (P less than 0.0001). Flow increases in C2 and C5 over C3 and C4 were modest (25%-50%) compared with C1 (250%). Therefore, we do not recommend removing or cutting the obturator to improve flow. During massive transfusion, we recommend removal of the side port until smaller flows suffice.