Objective: Intestinal mucosal ischemia can occur during and after cardiac surgery. Severe decreases in mucosal perfusion may be a causative factor for postoperative mortality or complications such as necrotizing enterocolitis. Mesenteric perfusion is challenged preoperatively due to an imbalance between the systemic and pulmonary circulations and challenged intraoperatively due to hypothermic circulatory arrest. We have investigated gut permeability in seven patients undergoing stage 1 of the Norwood procedure, applying the dual sugar permeability test with L-rhamnose and lactulose.
Design: Seven patients with hypoplastic left heart syndrome: clinical presentation, gut permeability findings, and outcome.
Setting: A 10-bed mixed pediatric intensive care unit in a university hospital.
Patients: Seven patients admitted for postoperative care after cardiac surgery.
Interventions: Determination of gut permeability with the dual sugar permeability test using lactulose and rhamnose. Intestinal permeability was measured after induction of anesthesia and 12 and 24 hrs later.
Measurements and main results: : All patients had abnormal lactulose/rhamnose ratios. One patient, who had a lactulose/rhamnose ratio 12 hrs after surgery of 2.3 (46-times normal), developed necrotizing enterocolitis postoperatively and died 3 days after surgery.
Conclusions: Gut permeability as assessed by the dual sugar permeability test is abnormal in patients with hypoplastic left heart syndrome before and after surgery. Lactulose/rhamnose ratios 46 times the normal value reflect a highly permeable small intestine. This may be a sign of a low output state and may help to identify patients at risk of developing necrotizing enterocolitis.