A system for use in treating a tissue site e.g. a site exhibiting or at risk for developing compartment syndrome the system including a monitor for use in controlling the function and operation of one or more apparatuses providing insertable catheters. The system includes at least one apparatus having a catheter portion that includes both a suitably protected functional device tip adapted to be positioned and used within the tissue site and one or more hollow fiber membranes e.g. an array of such membranes adapted to be positioned within the tissue site in order to simultaneously collect fluid therefrom. The catheter portion is adapted to be safely inserted and positioned within the tissue site in a manner that permits it to function there while substantially minimizing direct impingement of the non fluid tissue on the functional device tip surface.
