In Isern v. Ninth Court of Appeals, 925 S.W.2d 604 (Tex. 1996), the Supreme Court recognized that, in certain instances, the general rule requiring bond or other security in the total amount of a money judgment may effectively deny an appellant the right to appeal. To guard against that possibility and yet protect the judgment creditor's right to collect its judgment, the provisions for reduced or alternate security were adopted. Id. at 605. Although the wording of the specific rule authorizing a reduction or alternate security has been changed slightly, the basic requirement has not been changed since the enactment of the rule permitting modified supersedeas in 1988: the party seeking alternate security must prove that posting security for the full amount of the judgment would cause irreparable harm to the judgment debtor, and that failing to post the full bond would cause no substantial harm to the judgment creditor. Under Rule 24.4(a), on review of the trial court's order by the court of appeals, the court may review: (1) the sufficiency or excessiveness of the amount of security; (2) the sureties on any bond; (3) the type of security; (4) the determination whether to permit suspension of enforcement; (5) the trial court's exercise of discretion under TEX. R. APP. P. 24.3(a). The abuse of discretion standard requires us to determine whether the trial court acted without reference to guiding rules or principles, or acted in an arbitrary or unreasonable manner. Burlington N. R.R. Co. v. Southwestern Elec. Power Co., 905 S.W.2d 683, 686 (Tex. App.-Texarkana 1995, no writ). In addition, under Rule 24.4(b), which provides that the appellate court's review may be based both on conditions existing at the time the trial court signed the order and on changes in those conditions afterward, we may consider evidence of changed conditions affecting the determination.