Optimal filling solution for silicone Foley catheter balloons

We assessed whether saline, sterile water, or air better maintained filling volume and diameter in a veterinary silicone Foley bulb. The bulbs of 45 8-French silicone Foley catheters were inflated: 15 with 5 mL of sterile water (SW bulbs), 15 with 0.9% saline (S bulbs), and 15 with air (A bulbs). The bulbs were submerged in 30 mL of synthetic urine in a 50 mL conical tube in a 38°C water bath. Five catheters from each group were removed on days 3, 5, and 10 to measure bulb volume and diameter. On days 3 and 5, volume and diameter of SW or S bulbs were significantly greater than those of A bulbs, but were not significantly different from one another. At day 10, only 1 S bulb remained intact, 4 of the 5 SW bulbs were intact, the average volume of the SW bulbs was 2.8 mL, and the A bulbs were all deflated. We conclude that sterile water and 0.9% saline are both acceptable for Foley bulb inflation of 5 d or less, but sterile water might be preferred if bulb inflation must be maintained for more than 5 d.