Safety catheter using a secondary balloon and tertiary lumen

A method comprising:

• receiving, via a fluid inlet valve of a catheter a first fluid injected into a second lumen defined by the catheter, the catheter also defining a first lumen that connects a drainage inlet at a proximal end of the catheter to a drainage outlet at a distal end of the catheter;
• inflating a retention balloon of the catheter by conveying the first fluid from the second lumen into the retention balloon, the retention balloon being located between the drainage inlet and the drainage outlet;
• draining a second fluid from a subject by conveying the second fluid from the drainage inlet to the drainage outlet via the first lumen;
• and
• shunting, via a third lumen of the catheter and in response to an external force applied to the retention balloon, the first fluid from the retention balloon into a secondary balloon of the catheter, wherein the secondary balloon forms a closed end of the third lumen.

A catheter comprising:

• means for retaining the catheter in a hollow viscera of a subject;
• means for draining a first liquid from the hollow viscera of the subject;
• means for inflating, with an inflation means, the means for retaining the catheter in the hollow viscera of the subject;
• and
• means for shunting the fluid from the means for retaining the catheter in the hollow viscera of the subject to a balloon forming a closed end to the means for shunting.