Table 2: Open-abdomen-associated complications in patients with intra-abdominal infection.

ComplicationPossible reasons

Enteroatmospheric fistulae(1) The bowel is exposed into air and allowed to desiccate; (2) “biomaterial adherence” to the bowel would lead to transmural changes of the bowel wall; (3) bowels became edema and vulnerable to bacteria invasion due to the capillary leak syndrome; (4) persistent negative nitrogen balance complicated from IAI; (5) decreased intestinal microvessel circulation from IAH or surgical packing; (6) delayed perforation due to operation associated injuries.

Fluid, protein, and heat loss(1) A large, moist surface area of the intestine is exposed and could suffer huge evaporative water losses, further deteriorated if enteroatmospheric fistula occurred; (2) the increased metabolic demands during IAI, combined with the loss of bowel motility; (3) relatively poor nutrition status and rapid accumulation of third space fluid.

Bleeding/hemorrhage(1) Given the rich blood supply of bowels and splanchnic organs, the risk of bleeding is significantly increased, especially when inflamed or traumatized bowel wall is exposed to air; (2) the infected patients with an open abdomen often have an associated coagulopathy from hypothermia, acidosis, hypotension, dilution of blood volume, and uncontrolled exhaustion of clotting factors; (3) extensive complement activation or complement depletion disrupts the coagulation system.

Postoperative ileus(1) Massive electrolyte loss from the exposed wound areas after an open abdomen, in particular for potassium and magnesium; (2) postoperative adhesion often occurred after the initial operation.

Abdominal wall hernia(1) Extensive abdominal wall defect cannot be repaired with skin-only closure; (2) planned reconstruction surgery is required due to a wide resection of abdominal fascia in initial OA procedure.

Bacterial translocation/ sepsis/MODS/MOFMucous damages from the capillary leak syndrome and vicious cycle related to infected open abdomen (Figure 1).

SSI/VAP/ARDS/UTIDeclined immune function because of sustained infection status; iatrogenic infection.

Intra-abdominal abscessConcealed infection source or secondary perforation fixed by greater omentum.

DVT/PEUncommon.

SSI: surgical site infection; VAP: ventilator-associated pneumonias; DVT: deep vein thrombosis; PE: pulmonary embolism; ARDS: acute respiratory distress syndrome; UTI: urinary tract infection.