Ok, I'll try and respond to your question (but remember I'm not a FL Atty). First, keep in mind that the House subpoenas have a return date of March 25, so compliance, or non-compliance, with the subpoenas can not be determined until that date. Next, if you review the House's petition at the above link you will see that they attempted to intervene in the "In re guardianship of Terri Schiavo" matter which has been ongoing since 1990 I believe (case no.: 90-2908-GD-003). Generally, there are two types of intervention - intervention of right and permissive intervention. The trial court ruled that the House did not present a sufficient basis to intervene in the "in re guardianship" action, and which the House is now appealing. By my reading, the House was not seeking to intervene to ENFORCE the subpoenas, rather they were seeking to intervene to get an injunction against the removal of the feeding tube in order to help ensure that when the 25th arrives Terri (with the feeding equipment in place and operating - which is what the subpoenas seek) will be available to be seen at the Congressional Field Hearings at the Hospice. Actual enforcement of the Federal subpoenas would appropriately be handled in Federal Ct. (even prior to the passage of last night legislation). Hope this helps clarify a bit more.
By denying that interlocutory appeal, the matter of intervention is stuck in the Florida Appellate Court and there is no other avenue, at least in the Florida state courts, to get reinsertion of the tube, as the matter awaits appellate review.
In the meantime, the subpoenas have been served and could still be enforced on March 25th. The problem with that is that the tube will have been out one week. This means that the decision of the federal judge will determine whether there is any reinsertion between now and the 25th.