pro re nata

1. The bone nonunion of humeral shaft fracture may be controlled by strict operation indications, protection of the blood supplies of fracture ends, suitable internal fixators, with firm external fixations pro re nata.
   而严格掌握手术适应证，注意保护断端周围血运，选择合适的内固定器材，并酌情结合可靠的外固定，可减少和避免骨不连的发生。

adv

1. according to need (physicians use PRN in writing prescriptions)
   1. add water as needed

   Synonym:    as neededas requiredPRN