Kathryn Higdon
Medical College of Wisconsin
Wauwatosa, Wisconsin
Disclosure information not submitted.
Theresa Mikhailov, MD, PhD
Professor of Pediatrics (Critical Care)
Childrens Hospital of Wisconsin, United States
Disclosure information not submitted.
John Scott, MD
Associate Professor, Anesthesiology and Pediatrics
Childrens Hospital of Wisconsin, United States
Disclosure information not submitted.
Wendi Redfern, RN, ACNS-BC, CCRN
Clinical Nurse Specialist
Children's Hospital of Wisconsin, United States
Disclosure information not submitted.
George Hoffman, MD
Medical Director and Chief, Pediatric Anesthesiology, Associate Director, Cardiac PICU
Childrens Hospital of Wisconsin, United States
Disclosure information not submitted.
Title: Mesenteric NIRS at Rest and During Feeding in Healthy Children
Background: In illness, mesenteric organs are at risk for ischemic injury. Near infrared spectroscopy (NIRS) measures tissue oxygen saturation, which is highly correlated with regional venous oxygen saturation and oxygen delivery. Mesenteric circulatory abnormalities are detectable with NIRS in neonates who develop necrotizing enterocolitis. In infants and children, normative values for mesenteric NIRS are not established, and utility of monitoring during feeding in critical illness is unclear. We designed this study to establish normal mesenteric NIRS values in healthy children and determine if there is a meaningful difference with enteral feeding.
Methods: We screened healthy infants and children between 1 month and 5 years for absence of gastrointestinal, cardiovascular, and dermatologic conditions and acute illness symptoms. We monitored the mesenteric circulation via bilateral NIRS probes placed over the mid-abdomen, with cerebral and renal NIRS monitored simultaneously. We monitored subjects for six hours that spanned meal consumption. Subjects’ parents kept activity logs and we categorized activity into asleep, calm, anxious, active, eating, and post-prandial states. We analyzed the association between regional oxygen saturations and clinical state using a fixed-effects model.
Results: Sixteen subjects (age 34±21 months, weight 13.6±4.8 kg) completed the study. In the calm state, average regional NIRS were cerebral 74.2±0.7, renal 86.0±0.9, right mesenteric 83.2±0.7, and left mesenteric 82.9±0.8. Compared to the calm state, in the anxious state, cerebral NIRS were unchanged, renal 7.7±1.0 lower (p< 0.001), right mesenteric 8.9±1.7 lower (p< 0.001) and left mesenteric 9.8±1.1 lower (p< 0.001). In the post-prandial state, cerebral NIRS were unchanged, renal 1.1±1.0 lower, right mesenteric 0.3±1.3 lower, and left mesenteric 2.0±0.7 lower (p< 0.01).
Conclusions: Regional circulations can be monitored by NIRS in children, with differences detectable between regions and states. Mesenteric NIRS were similar to renal NIRS, and both were influenced by state, particularly activity and anxiety, while cerebral NIRS showed little change. No systematic change occurred during feeding. NIRS monitoring of renal and mesenteric circulations may be warranted in children with critical illness.