A pilot study of cerebrovascular reactivity autoregulation after pediatric cardiac arrest

Abstract

Aim Improved survival after cardiac arrest has placed greater emphasis on neurologic resuscitation. The purpose of this pilot study was to evaluate the relationship between cerebrovascular autoregulation and neurologic outcomes after pediatric cardiac arrest. Methods Children resuscitated from cardiac arrest had autoregulation monitoring during the first 72 hours after return of circulation with an index derived from near-infrared spectroscopy in a pilot study. The range of mean arterial blood pressure (MAP) with optimal vasoreactivity (MAPOPT) was identified. The area under the curve (AUC) of the time spent with MAP below MAPOPT and MAP deviation below MAPOPT was calculated. Neurologic outcome measures included placement of a new tracheostomy or gastrostomy, death from a primary neurologic etiology (brain death or withdrawal of support for neurologic futility), and change in the Pediatric Cerebral Performance Category score (ΔPCPC). Results Thirty-six children were monitored. Among children who did not require extracorporeal membrane oxygenation (ECMO), children who received a tracheostomy/gastrostomy had greater AUC during the second 24 hours after resuscitation than those who did not (P=0.04; n=19). Children without ECMO who died from a neurologic etiology had greater AUC during the first 48 hours than did those who lived or died from cardiovascular failure (P=0.04; n=19). AUC below MAPOPT was not associated with ΔPCPC when children with or without ECMO were analyzed separately. Conclusions Deviation from the blood pressure with optimal autoregulatory vasoreactivity may predict poor neurologic outcomes after pediatric cardiac arrest. This experimental autoregulation monitoring technique may help individualize blood pressure management goals after resuscitation.

Association between blood pressure and outcomes in patients after cardiac arrest: A systematic review

“…39 Alternatively, near-infrared spectroscopy measures the regional saturation of oxygen (rSO 2 ) in the brain and has been shown to be a reasonable non-invasive measurement of CBF. 40 By examining the relationship between rSO 2 and MAP over time, a patient-specific optimal MAP can be determined, 41 as has been recently done in several small observational studies. 20,42 Similar approaches in patients with traumatic brain injury, an injury which shares overlapping features with HIBI, has been associated with reduced mortality and improved neurologic outcomes.…”

Cerebral Autoregulation and Conventional and Diffusion Tensor Imaging Magnetic Resonance Imaging in Neonatal Hypoxic-Ischemic Encephalopathy

“…We then determined blood pressure deviation from optimal MAP during three separate periods (hypothermia, rewarming, and the first six hours of normothermia) using three parameters: (1) maximal blood pressure deviation above or below optimal MAP; (2) percentage of the monitoring period with blood pressure within, below, or above optimal MAP; and (3) the area under the curve (min × mm Hg/h) to combine time (minutes) and blood pressure deviation (mm Hg) below optimal MAP normalized by the monitoring duration (hours). 10,11 To describe optimal MAP, we report the average MAP within the 5 mmHg bin of optimal MAP. For example, an optimal MAP of 50 mmHg represents the bin 47.5–52.5 mmHg.…”

“…7–10 Conceptually, optimal MAP is located in the center of the blood pressure-cerebral blood flow autoregulation plateau. Vasoreactivity decreases and autoregulation becomes progressively more dysfunctional as blood pressure deviates from optimal MAP.…”

Optimizing Cerebral Autoregulation May Decrease Neonatal Regional Hypoxic-Ischemic Brain Injury

“…Blood pressure was analyzed as the (1) maximal blood pressure deviation below or above MAP OPT ; (2) duration with blood pressure below, within, or above MAP OPT analyzed as a percentage of the autoregulation monitoring period; and (3) area under the curve (AUC; min* mmHg/h) to combine time (min) spent with blood pressure below MAP OPT and blood pressure deviation (mmHg) below MAP OPT normalized for the monitoring duration (h) in each period. [4, 15] We also calculated the percentage of the hypothermia, rewarming, and normothermia periods that neonates spent with MAP below gestational age (weeks)+5, a common clinical guide for neonatal hemodynamic goals. [16]…”