The effect of intra-abdominal hypertension on gastrointestinal function

Abstract

Introduction: Intra-abdominal hypertension (IAH) is a frequent occurrence in critically ill patients. Raised intra-abdominal pressure negatively affects gastrointestinal function and may reduce the success of enteral nutrition support, which in turn is associated with adverse clinical outcomes.
Aim: To evaluate the impact of raised intra-abdominal pressure on gastrointestinal function and success of enteral nutrition support in an adult ICU population at risk for abdominal compartment syndrome.
Methods: In a prospective observational study, critically ill patients, in whom IAP was monitored routinely for clinical indications, were assessed for gastrointestinal symptoms, methods of nutrition support and enteral feeding success on a daily basis.
Results: In total, data from 17 patients for a total of 98 patient days was included in the study. The mean intra-abdominal pressure (IAP) was 14.0 ± 3.7 on admission to the intensive care unit (ICU). There were 10 patients with Grade I IAH, 2 with Grade II IAH and 2 with Grade III IAH. Seven (41%) patients developed abdominal compartment syndrome. Abdominal perfusion pressure was inversely related to IAP (r = -0.35, p=0.0002) and positively correlated with mean arterial pressure (r = 0.96, p= 0.000). Gastrointestinal (GI) symptoms occurred commonly in patients with IAH, and days of IAH correlated positively with number of GI symptoms (r=0.85, p=0.000). Exclusive enteral feeding was possible on 32% of study days. A 12% incidence of enteral feeding intolerance and 59% incidence of enteral feed failure occurred. Enteral feeding failure was associated with both IAH (r= 0.43, p=0.08) and number of GI symptoms (r= 0.67, p= 0.003). Days of IAH was positively associated with longer ICU stay (r = 0.65, p=0.005), as was prevalence of IAH combined with concurrent GI symptoms (r=0.71, p=0.001). Mortality was 17% and occurred only among patients who developed abdominal compartment syndrome.
Conclusion: Raised intra-abdominal pressure was associated with poorer gastrointestinal function, enteral feed intolerance, length of hospital stay and mortality.