Association between Brain and Kidney Near-Infrared Spectroscopy and Early Postresuscitation Mortality in Asphyxiated Newborn Piglets

Abstract

Background: Early outcome predictors after delivery room cardiopulmonary resuscitation (CPR) of asphyxiated newborns are needed. Objectives: To investigate if cerebral (rScO₂) and renal (rSrO₂) tissue oxygen saturation 30 min after return of spontaneous circulation (ROSC) are different between surviving versus nonsurviving piglets with asphyxia-induced cardiac arrest and CPR. Further, to investigate the relationship of rScO₂ and rSrO₂ to cardiac output (CO), blood pressure (BP), and biochemical variables 30 min and 4 h after ROSC. Methods: Anesthetized, mechanically ventilated piglets (1-3 days, 1.7-2.4 kg) were used. rScO₂, rSrO₂, SpO₂, right common carotid artery flow, and arterial BP were measured continuously. CO was measured with echocardiography. The piglets were asphyxiated until cardiac arrest and resuscitated. Piglets that survived 4 h after ROSC (n = 12) were compared with piglets that died before planned euthanasia at 4 h (n = 13). Left ventricular, and kidney and brain tissue lactate were analyzed. Correlations between variables were assessed. Results: Thirty minutes after ROSC, median rSrO₂ (43% [n = 10] vs. 25% [n = 2], p = 0.003) but not rScO₂ (46% [41-55] [n = 10] vs. 40% [22-45] [n = 5], p = 0.08) was higher in survivors than in nonsurvivors. Arterial lactate was negatively correlated and pH positively correlated with rScO₂ and rSrO₂. Left ventricular, but not kidney or brain lactate was negatively correlated with rScO₂ and rSrO₂. There was no correlation between CO or BP and rScO₂ or rSrO₂. Conclusions: Despite satisfactory CO and BP vital organ oxygenation can be poor. Tissue oxygen saturation, pH, and lactate, as measures of anaerobic metabolism, may reflect vital organ oxygenation and outcome.

Chest Compression in Neonatal Cardiac Arrest: Cerebral Blood Flow Measurements in Experimental Models

“…Near-infrared spectroscopy (NIRS) has been utilized in numerous CC studies of newborn animals [18][19][20]. NIRS is a non-invasive monitoring technique that measures regional cerebral oxygenation (rcSO 2 ) continuously [21].…”