We're getting way ahead of things by talking about foreclosures. Until you say otherwise, I'm going to assume that this is a credit card debt, or something similar, and an ordinary collection lawsuit (i.e., they're asking for money). I'll say this much: If this is a foreclosure of a junior lien (of only $5,400) and you have equity in your home, find a way to pay off the $5,400 -- but given the cost of foreclosure, if there is a senior lienholder and not much equity that's not a step that a junior lienholder is apt to take.
You need to file some sort of answer with the court to avoid default.
If this is a credit card, between the fact that the debt is dischargeable in bankruptcy, the fact that collection efforts actually cost them money (that they can try to recover from you, but only if you have it -- and that, too, would be dischargeable in bankruptcy), adn that they have little incentive to spend many thousands of dollars to try to chased down and collect a @$5,400 judgment when you may not even be able to pay the judgment itself, you can relax a bit.
In most cases, with a judgment of that size, the creditor might try to collect through garnishment of financial accounts (e.g., checking and saving, but not retirement accounts) or through wage garnishment.

