Objectives: In adult patients, intramucosal pH (pHi) has been advocated to detect postoperative complications. The purpose of our study was to evaluate this technique in pediatric patients during and after cardiac surgery.
Methods: Thirty-five infants (age: 5 days to 15 years, median 1.8 years; and weight: 3.2-32 kg, median 9.8 kg) were studied. pHi was measured before cardiopulmonary bypass (CPB), after 30 min of CPB, prior to weaning off CPB, at intensive care unit arrival, and 6, 12, 24, 48 and 72 h after surgery.
Results: There were no complications related to the tonometer. A pathologically low pHi < 7.32 was found during surgery in less than 17%, at intensive care unit arrival in 83% and after 48 h in 18%. pHi values were lower (P < 0.05) at intensive care unit arrival (7.25 +/- 0.08) and after 6 h (7.28 +/- 0.09) than afterwards. pHi correlated with arterial pH (r = 0.66), central-peripheral temperature difference (r = -0.36), lactate (r = -0.32) and central venous pressure (r = -0.21). Patients after a Fontan procedure had postoperatively a lower pHi than after other operations (P < 0.05). None of the patients died or developed organ failure. Six patients had signs of organ dysfunction. Their pHi (median 7.23, range 7.14-7.28) could not differentiate them from the other patients.
Conclusions: With current equipment, tonometry cannot be recommended for the management of pediatric patients after cardiac surgery. However, as a semi-invasive method tonometry deserves further evaluation.