Disfungsi gastrointestinal pascabedah risiko tinggi di ICU: Kajian terhadap kadar intestinal Fatty Acid Binding Protein (I-FABP), skor SOFA, balans cairan dan dosis vasopresor = Gastrointestinal dysfunction after high risk surgery in ICU: Study of Intestinal Fatty Acid Binding Protein (I-FABP) levels, SOFA score, fluid balance and vasopressor doses