ohiocoder,
First, if providing continuous "epidural" postoperative pain management service the code would be 01996 and not 99231.
Second, if providing continous peripheral nerve block postoperative pain managment service, many insurance carriers have implemented a "global period" for anesthesia. You will need to clarify by payer what they are defining as the global period and, if appropriate, add the -24 modifier to the E&M code(s) for the continuous peripheral nerve block rounds if they are not related to the anesthesia service.
For example, UHC has anesthesia global period information in their written anesthesia policy which may be viewed at uhconline.com
Hope this helps.
Julie, CPC