Table 1 Physiological factors impacting on intra abdominal pressure (IAH)

Related to diminished abdominal wall compliance

• High BMI

• Pregnancy

• Mechanical ventilation

• The use of PEEP or when auto PEEP is present

• Basal pneumonia

• Pneumoperitoneum

• Abdominal surgery particularly with tight abdominal closures

• Pneumatic anti shock garments

• Prone positioning

• Abdominal wall bleeding or abdominal hematoma

• Burns with abdominal eschars

Related to increased intra-abdominal contents

• Gastro paresis

• Gastric distension

• Ileus

• Volvulus

• Bowel pseudo obstruction

• Abdominal hematoma

• Intra-abdominal or retroperitoneal hematoma

• Damage control laparotomy

• Liver dysfunction with ascites

• Abdominal infection (peritonitis, pancreatitis)

• Hemoperitoneum

• Pneumoperitoneum

• Major trauma

• Excessive inflation during laparoscopy

• Peritoneal dialysis

Related to capillary leak and fluid resuscitation

• Acidosis (pH below 7.2)

• Hypothermia (core temp below 33°

• Coagulopathy

• Multiple transfusions/trauma (>10 units in 24 hours)

• Sepsis, severe sepsis or bacteraemia

• Septic shock

• Massive fluid resuscitation (>5 L colloid or > L crystalloid in 24 hours in the presence of capillary leak and a positive fluid balance)

• Major burns