To me, it doesn't make a whole lot of sense to imprison a patient in the hospital because the INR is low. They tried to do this to me a month ago after I had a stroke, and the lab determined that my INR was 1.7. (My meter, 36 hours earlier, gave me a 2.6). The attending doctor finally found a doctor who knew more about anticoagulation than he did, and, after a bit of insistence on my part that staying in the hospital didn't make a lot of sense, they agreed to discharge me with four days' worth of generic Lovenox. (In other words, they sent me home where I could bridge until my INR went up).
Suggest to your doctors that you can bridge at home, increase your dose (if necessary) while at home, and either self-test, or come to the hospital daily (or however often they're comfortable) for a repeat blood test.
If INR is the only reason that they're keeping you in the hospital (other than maintaining the hospital's occupancy rate and charging you or your insurance company for practically nothing at all), you should be able to convince them to let you go home and bridge for a few days until your INR gets in range. (Warfarin is very slow acting, so it may take a while until your INR responds to increased dosing -- just don't increase too much, too fast, or you may wind up on the 'INR Roller Coaster,' bouncing between INRs that are too high and INRs that are too low.