Gut mucosal perfusion in neonates undergoing cardiopulmonary bypass

Abstract

We studied gut mucosal perfusion in 24 neonates requiring cardiopulmonary bypass (CPB). Group A patients (n = 12) had obstruction to their aorta such that gut perfusion before operation was dependent on flow through a ductus arteriosus (DA). Group B neonates were of similar age and size and required a similar duration of CPB, but did not have a DA. An orogastric tonometer allowed intermittent calculations of gastric intramucosal pH (pHi), and rectal mucosal perfusion ("flux") was monitored using laser Doppler flowmetry. Measurements of arterial base deficit, and lactate and pyruvate concentrations were made intermittently. Before CPB, mean femoral arterial pressure (MAP) and base deficit in group A were not significantly different from those in group B. However, mean flux before CPB was significantly lower and the lactate/pyruvate (L/P) ratio was significantly higher in group A compared with group B. Mean pHi was below normal (< 7.26) throughout the operative period in group A, although it remained normal (> 7.33) in group B. After corrective surgery, both during warm CPB and after CPB, we found no significant difference in MAP, L/P ratio or base deficit between the groups, but both flux and pHi were significantly lower in group A compared with group B. We conclude that neonates requiring aortic arch surgery may be at particular risk of gut mucosal hypoxia both before and after operation.

A new device for continuous assessment of gut perfusion: proof of concept on a porcine model of septic shock

“…Several methods can be used to assess microcirculation, including downstream markers such as tonometry, capnometry, microdialysis, biomarkers such as lactate and direct assessment tools such as LD or video microscopy (orthogonal polarization spectral and sidestream darkfield imaging techniques) [19]. LD has been widely used to assess gut perfusion in different clinical settings [25], surgeries [26,27] or sepsis [28]. Photoplethysmography is an optical method that has already been used for other medical applications such as measurement of oxygen saturation, evaluation of blood pressure and cardiac output, and assessment of autonomic function [9].…”

Gut permeability in paediatric cardiac surgery

“…Neonates with aortic arch anomalies and infants subjected to CPB-induced profound hypothermia may be at particular risk of developing splanchnic ischaemia in the perioperative period. 3 Patients with coarctation of the aorta may, on the other hand, be exposed to reperfusion injuries after the surgical repair, manifesting as the postcoarctectomy syndrome. 4 The previous studies have used indirect indicators of intestinal mucosal perfusion (e.g.…”

Intestinal Mucormycosis in Neonates – A Surgical Disease

“…In our patients transient intestinal ischemia might have increased the susceptibility of the intestine for invasive mucormycosis. Open cardiac bypass surgery was necessary in both infants and might have induced mucosal changes favoring the development of an opportunistic intestinal infection [14,15]. Corresponding to these findings Nichol et al reported a preterm female infant presenting with intestinal mucormycosis five days after being weaned off the extracorporeal membrane oxigenation (ECMO), suggesting a similar pathogenesis [16].…”