Table 2 Summary of statements

 Trauma patients

Persistent hypotension, acidosis (pH <7.2), hypothermia (temperature < 34°C) and coagulopathy are strong predictors of the need for abbreviated laparotomy and open abdomen in trauma patients (Grade 2A)

Risk factors for abdominal compartment syndrome such as damage control surgery, injuries requiring packing and planned reoperation, extreme visceral or retroperitoneal swelling, obesity, elevated bladder pressure when abdominal closure is attempted, abdominal wall tissue loss and aggressive resuscitation are predictors of the necessity for open abdomen in trauma patients (Grade 2B)

Decompressive laparotomy is indicated in abdominal compartment syndrome if medical treatment has failed after repeated and reliable IAP measurements (Grade 2B)

The inability to definitively control the source of contamination or the necessity to evaluate the bowel perfusion may be an indicator to leave the abdomen open in post-traumatic bowel injuries (Grade 2B)

 Non-trauma patients

Decompressive laparotomy is indicated in abdominal compartment syndrome if medical treatment has failed after repeated and reliable IAP measurements (Grade 2B)

  ➢ Peritonitis

The open abdomen is an option for emergency surgery patients with severe peritonitis and severe sepsis/septic shock under the following circumstances: abbreviated laparotomy due to the severe physiological derangement, the need for a deferred intestinal anastomosis, a planned second look for intestinal ischemia, persistent source of peritonitis (failure of source control), or extensive visceral oedema with the concern for development of abdominal compartment syndrome (Grade 2C).

  ➢ Vascular emergencies

The open abdomen should be considered following management of hemorrhagic vascular catastrophes such as ruptured abdominal aortic aneurysm (Grade 1C)

The open abdomen should be considered following surgical management of acute mesenteric ischemic insults (Grade 2C).

  ➢ Pancreatitis

In patients with severe acute pancreatitis unresponsive to step-up conservative management surgical decompression and open abdomen open are effective in treating abdominal compartment syndrome (Grade 2C)

Leaving the abdomen open after surgical necrosectomy for infected pancreatic necrosis is not recommended except in those situations with high risk factors to develop abdominal compartment syndrome (Grade 1C)

 Trauma and non-trauma patients

The role of Damage Control Resuscitation in OA management is fundamental and may influence outcome (Grade 2A)

  ICU management

A multidisciplinary approach is encouraged, especially during the patient’s ICU admission (Grade 2A)

Intra-abdominal pressure measurement is essential in critically ill patients at risk for IAH/ACS (Grade 1B)

Physiologic optimization is one of the determinants of early abdominal closure (Grade 2A)

Inotropes and vasopressors administration should be tailored according to patient condition and performed surgical interventions (Grade 1A)

Fluid balance should be carefully scrutinized (Grade 2A)

High attention to body temperature should be given, avoiding hypothermia (Grade 2A)

In presence of coagulopathy or high risk of bleeding the negative pressure should be down regulated balancing the therapeutic necessity of negative pressure and the hemorrhage risk (Grade 2B).

  Technique for temporary abdominal closure

Negative pressure wound therapy with continuous fascial traction should be suggested as the preferred technique for temporary abdominal closure (Grade 2B).

Temporary abdominal closure without negative pressure (e.g. Bogota bag) can be applied in low resource settings accepting a lower delayed fascial closure rate and higher intestinal fistula rate (Grade 2A).

No definitive recommendations can be given about temporary abdominal closure with NPWT in combination with fluid instillation even if it seems to improve results in trauma patients (Not grades).

  Re-exploration before definitive closure

Open abdomen re-exploration should be conducted no later than 24-48 hours after the index and any subsequent operation, with the duration from the previous operation shortening with increasing degrees of patient non-improvement and hemodynamic instability (Grade 1C).

The abdomen should be maintained open if requirements for on-going resuscitation and/or the source of contamination persists, if a deferred intestinal anastomosis is needed, if there is the necessity for a planned second look for ischemic intestine and lastly if there are concerns about abdominal compartment syndrome development (Grade 2B).

  Nutritional support

Open abdomen patients are in a hyper-metabolic condition; immediate and adequate nutritional support is mandatory (Grade 1C).

Open abdomen techniques result in a significant nitrogen loss that must be replaced with a balanced nutrition regimen (Grade 1C).

Early enteral nutrition should be started as soon as possible in presence of viable and functional gastrointestinal tract (Grade 1C).

Enteral nutrition should be delayed in patients with an intestinal tract in discontinuity (temporarily stapled stumps), or in situations of a high output fistula with no possibility to obtain feeding access distal to the fistula or with signs of intestinal obstruction (Grade 2C)

Oral feeding is not contraindicated and should be used where possible (Grade 2C).

  Patient mobilization

To date, no recommendations can be made about early mobilization of patients with open abdomen (Not graded).

 Trauma and non-trauma patients

Fascia and/or abdomen should be definitively closed as soon as possible (Grade 1C).

  Open abdomen definitive closure

Early fascial and/or abdominal definitive closure should be the strategy for management of the open abdomen once any requirements for on-going resuscitation have ceased, the source control has been definitively reached, no concern regarding intestinal viability persist, no further surgical re-exploration is needed and there are no concerns for abdominal compartment syndrome (Grade 1B).

   ➢ Non-mesh-mediated techniques

Primary fascia closure is the ideal solution to restore the abdominal closure (2A).

Component separation is an effective technique; however it should not be used for fascial temporary closure. It should be considered only for definitive closure (Grade 2C).

Planned ventral hernia (skin graft or skin closure only) remains an option for the complicated open abdomen (i.e. in the presence of entero-atmospheric fistula or in cases with a protracted open abdomen due to underlying diseases) or in those settings where no other alternatives are viable (Grade 2C)

   ➢ Mesh-mediated techniques

The use of synthetic mesh (polypropylene, polytetrafluoruroethylene (PTFE) and polyester products) as a fascial bridge should not be recommended in definitive closure interventions after open abdomen and should be placed only in patients without other alternatives (Grade 1B).

Biologic meshes are reliable for definitive abdominal wall reconstruction in the presence of a large wall defect, bacterial contamination, comorbidities and difficult wound healing (Grade 2B).

Non–cross-linked biologic meshes seem to be preferred in sublay position when the linea alba can be reconstructed. (Grade 2B).

Cross-linked biologic meshes in fascial-bridge position (no linea alba closure) maybe associated with less ventral hernia recurrence (Grade 2B).

NPWT can be used in combination with biologic mesh to facilitate granulation and skin closure (Grade 2B).

 Trauma and non-trauma patients

Preemptive measures to prevent entero-atmospheric fistula and frozen abdomen are imperative (i.e. early abdominal wall closure, bowel coverage with plastic sheets, omentum or skin, no direct application of synthetic prosthesis over bowel loops, no direct application of NPWT on the viscera and deep burying of intestinal anastomoses under bowel loops) (Grade 1C).

Entero-atmospheric fistula management should be tailored according to patient conditions, fistula output and position and anatomical features (Grade 1C)

In the presence of entero-atmospheric fistula the caloric intake and protein demands are increased; the nitrogen balance should be evaluated and corrected and protein supplemented (Grade 1C).

Nutrition should be reviewed and optimized upon recognition of entero-atmospheric fistula (Grade 1C)

Entero-atmospheric fistula effluent isolation is essential for proper wound healing. Separating the wound into different compartments to facilitate the collection of fistula output is of paramount importance (Grade 2A).

In the presence of entero-atmospheric fistula in open abdomen, negative pressure wound therapy makes effluent isolation feasible and wound healing achievable (Grade 2A).

Definitive management of entero-atmospheric fistula should be delayed to after the patient has recovered and the wound completely healed (Grade 1C).