Neurologic outcomes in pediatric cardiac arrest survivors enrolled in the THAPCA trials

Abstract

Objective: To implement a standardized approach to characterize neurologic outcomes among 12-month survivors in the Therapeutic Hypothermia after Pediatric Cardiac Arrest (THAPCA) trials.

Methods: Two multicenter trials enrolled children age 48 hours to 18 years who remained comatose after cardiac arrest (CA) occurring out-of-hospital (THAPCA-OH, NCT00878644) or in-hospital (THAPCA-IH, NCT00880087); patients were randomized to therapeutic hypothermia or therapeutic normothermia. The primary outcome, survival with favorable 12-month neurobehavioral outcome (Vineland Adaptive Behavior Scales [VABS-II]), did not differ between treatment groups in either trial. Neurologists examined 181 12-month survivors, described findings using the novel semi-quantitative Pediatric Resuscitation after Cardiac Arrest (PRCA) form, and rated findings in 6 domains; scores ranged from 0 (no deficits) to 21 (maximal deficits). PRCA scores were compared with 12-month VABS-II scores and cognitive scores.

Results: Neurologic outcome PRCA scores were classified as no/minimal impairment, PRCA 0-3, 81/179 (45%); mild impairment, PRCA 4-7, 24/179 (13%); moderate impairment, PRCA 8-11, 15/179 (8%); severe impairment, PRCA 12-16, 20/179 (11%); profound impairment, PRCA 17-21, 39/179 (21%) (2/181 incomplete). VABS-II scores correlated strongly with PRCA category (r = -0.88, p < 0.0001, Pearson correlation coefficient) and cognitive scores (r = -0.72, p < 0.0001). Factors associated with poor outcomes included out-of-hospital CA, seizure recognition in the early postarrest period, and poor neurologic status at hospital discharge.

Conclusion: The PRCA provides a robust method for depicting neurologic outcomes after acute encephalopathy caused by CA in children. It provides a global semiquantitative rating of neurologic impairment and domain-specific impairment. The strong correlation with well-established neurobehavioral outcome measures supports its validity over a broad age range and wide spectrum of outcomes.

Figure 1. Relationship of 12-month Pediatric Resuscitation after Cardiac Arrest (PRCA) and Vineland Adaptive Behavior Scales, Second Edition (VABS-II) scores

Data demonstrate a strong relationship between month 12 VABS-II composite score (mean 100, SD 15) on the Y axis and global PRCA score (range 0–21), divided into 5 strata of severity, on the X axis (r = −0.877, p < 0.0001, Pearson correlation coefficient). Data are presented for all cases (left bar), in-hospital (IH) (middle bar), and out-of-hospital (OH) (right bar) groups, as box and whisker plots. Number of patients is shown along the X axis in each group for each stratum. Each shaded box represents the interquartile range (IQR) (middle one-half of the data), the horizontal line within the box is the median, and symbols (◇) are means; upper and lower whiskers represent the maximum and minimum values, excluding outliers (defined as data points more than 1.5 IQRs from the box).

Figure 2. Relationship between 12-month Pediatric Resuscitation after Cardiac Arrest (PRCA) score (range 0–21) and v Pediatric Cerebral Performance Category (PCPC) scores (range 0–5) at hospital discharge

Data are presented for all cases (left bar), in-hospital (IH) (middle bar), and out-of-hospital (OH) (right bar) groups, as box and whisker plots; number of cases in each group are shown along the X axis. Each shaded box represents the interquartile range (IQR) (middle one-half of the data), the horizontal line within the box is the median, and symbols (◇) are means; upper and lower whiskers represent the maximum and minimum values, excluding outliers (defined as data points more than 1.5 IQRs from the box). Higher PRCA scores indicate more severe neurologic impairment. Overall there is a strong relationship between hospital discharge PCPC scores and 12-month PRCA scores (r = 0.74, Pearson correlation coefficient, p < 0.0001), but individual outlying cases are evident.