The 2nd character defines the particular body system or general physiological system or anatomical region involved.
In extracorporeal assistance and performance procedures, equipment outside the body is used to assist or perform a physiological function. Extracorporeal assistance and performance procedure codes have a first character value of “5”. The second character value for body system is physiological systems. There are three root operations in the extracorporeal assistance and performance section, as defined below:
The root operation Restoration contains a single procedure code that identifies extracorporeal cardioversion. The fourth character specifies the body system (e.g., cardiac, respiratory) to which extracorporeal assistance or performance is applied. The fifth character specifies the duration of the procedure, i.e., single, intermittent, continuous. For respiratory ventilation assistance or performance, the duration is specified in hours, i.e., < 24 hours, 24-96 hours or > 96 hours. The sixth character specifies the physiological function assisted or performed (e.g., oxygenation, ventilation) during the procedure. The seventh character qualifier specifies the type of equipment used, if any.