Is Hydrogen Breath Test with Lactulose Feasible for Measuring Gastrocecal Transit in Critically Ill Children? Pilot Study about Modification of the Technique

Introduction. Gastrocecal transit time (GCTT) can be measured by exhaled hydrogen after lactulose intake (lactulose-eH2 test). The objectives were to assess whether it is possible to carry out this test in critically ill children with and without mechanical ventilation (MV) and to analyze whether the results are consistent with clinical findings. Methods. Patients admitted to the Pediatric Intensive Care Unit (PICU) for more than 3 days were included. Those with gastrointestinal disease prior to admission were excluded. A modified technique to obtain eH2 from the ventilator tubes was performed. Results. Sixteen patients (37.5% boys) with a median age of 19 (5-86.5) months were included. Five patients (31.2%) were breathing spontaneously but lactulose-eH2 test could not be performed while it could be performed successfully in the 11 patients with MV. Seven patients (63.3%) did not show an eH2 peak. The other 4 showed a median time of 130 min (78.7-278.7 min) from lactulose intake to a 10 ppm eH2 peak. Children with an eH2 peak had intestinal movements earlier [6.5 (1.5-38.5) versus 44 (24-72) hours p = 0.545]. Conclusion. Although the designed adaption is useful for collecting breath samples, lactulose-eH2 test may not be useful for measuring GCTT in critically ill children.