Indwelling Arterial Sheath Management:
See Appendix G.
Indwelling femoral arterial sheaths are associated with a significant risk of thrombosis, embolization, and limb ischemia, and require careful management, particularly in austere and transport environments. The sheath should be flushed immediately after placement to clear blood from the sheath and prevent early thrombosis. In general, the sheath should be left in place during ongoing resuscitation or prior to transport, as premature removal may result in loss of vascular access, hemorrhage, or inability to rapidly re-establish aortic occlusion. All arterial sheaths must be maintained with continuous flow, maintained on pressure or frequently flushed (at least every hour) to prevent thrombosis. In a combat or austere environment, often this is best achieved with a pressure bag and arterial line transduction or, alternatively, continuous infusion of saline or heparinized saline when not contraindicated at a fixed low rate. Sheaths with stagnant blood will thrombose rapidly, particularly in deployed environments. If not on continuous flow, the sheath should be flushed at least hourly. A sheath that does not aspirate blood easily should be considered thrombosed until proven otherwise; in this circumstance, the sheath should not be flushed, as this may result in distal embolization of clotted blood, and management should proceed according to thrombosed sheath protocols (Appendix H). While the sheath remains in place, hourly neurovascular checks of the affected extremity are essential to identify complications in a timely manner. Prior to sheath removal, evaluation of sheath position and the access site is recommended, particularly when placement occurred under emergent conditions; this may be performed using physical examination, plain radiography, CT imaging with or without contrast, or angiography when available. The sheath should not be removed immediately prior to transport and is best removed in an environment capable of recognizing and managing vascular complications.