Evaluation of Closed Catheter Clamp over Hydrophilic Guidewire Central Venous Catheter Exchange Technique for Air Embolism Prophylaxis in an in vitro Model.

PURPOSE: To develop a reproducible in vitro model simulating central venous catheter (CVC) exchange with high potential for air embolization and test the hypothesis that a closed catheter clamp over Glidewire exchange technique will significantly reduce the volume of air introduced during CVC exchange.

MATERIALS & METHODS: The model consisted of a 16 Fr valved sheath, 240 mL container, and pressure transducer submerged in water in a 1200 mL suction canister system. Continuous wall suction was applied to the canister to maintain negative pressure at-7 mmHg or -11 mmHg. Each trial consisted of 0.035" hydrophilic Glidewire introduction, over-the-wire catheter exchange, and wire removal following clinical protocol. A total of 256 trials were performed, 128 trials at each pressure with the catheter clamp open (n = 64) or closed (n = 64) around the Glidewire.

RESULTS: There was a statistically significant lower volume of air introduced with closed clamp over-the-wire exchanges compared to open clamp exchanges at both pressures (two-tailed t-test, p < 0.001). At -7 mmHg, 48.0 mL ± 9.3 of air was introduced with open clamp and 20.6 mL ± 4.7 with closed clamp. At -11 mmHg, 97.8 mL ± 11.9 of air was introduced with open clamp and 37.8 mL ± 6.3 with closed clamp.

CONCLUSION: This study demonstrates the use of a reproducible in vitro model mimicking conditions causing air embolism during CVC exchange. Results show that CVC exchange using closed catheter clamp over Glidewire exchange technique significantly reduces the volume of air introduced per exchange.