Matthew P. Kirschen, Alexis A. Topjian, Robert A. Berg
Only 6–14% of children survive to hospital discharge following out-of-hospital cardiac arrests (OHCA) in developed countries., , , , , , , The reported rate of favorable neurologic outcomes among survivors varies widely from 38 to 91%., , , , , , , Differences in favorable neurologic outcome may be related to differences in bystander CPR rates, quality of CPR, termination/withdrawal of technologic support, and/or the definition of favorable neurologic outcome. The neurologic outcome is typically reported as a crude qualitative assessment of neurologic functioning based on the Utstein-style recommended Pediatric Cerebral Performance Category (PCPC) or the Glasgow-Pittsburgh Cerebral Performance Category., , ,
In this issue of Resuscitation, Michiels and colleagues report the long-term neurologic status of children who survived OHCA from January 1976 to December 2007. They retrospectively determined the PCPC score of 91 children based on chart review of the “history and physical examination” at the time of hospital discharge from their OHCA and then again after subsequent hospital admissions or clinic visits. We applaud the efforts of the investigators for undertaking this challenging and laborious task. Children in this study were followed a median 4 years after hospital discharge. Encouragingly, 94% of children with a favorable neurologic status at hospital discharge, defined as a PCPC of 1 or 2 (normal or mild disability), maintained a favorable status at long-term follow-up. Similarly, 92% of children with an unfavorable neurologic status at discharge, defined as PCPC 3, 4 or 5 (moderate disability, severe disability, coma or vegetative state) either maintained an unfavorable neurologic status (38%) or died (54%). While these data partially reaffirm the commonly held belief that neurologic status after resuscitation from cardiac arrest does not appreciably change after hospital discharge, the most intriguing aspect of these results are the small percentage of children whose neurologic status declined or improved over time. Given the retrospective nature of these data and the imprecision of the PCPC score, this percentage may be an underestimate of the number of children who experienced more subtle changes in their neurocognitive or neurobehavioral functioning over time.
Interestingly, many patients transitioned to better neurologic status over time and some to worse. Eleven children had improved neurologic function over the years, and three transitioned from a severe disability category (PCPC 4) to a favorable neurologic status (PCPC 1 or 2). These observations suggest that some children whose initial neurologic assessment indicates a moderate to severe brain injury may be able to recover significant neurologic function. Four children who were categorized as having a favorable neurologic outcome had a decline in their neurologic status, and two transitioned into an unfavorable category. This may be due to the phenomena that some deficits become evident as children mature and fail to meet developmental or scholastic expectations or that morbidities worsen over time. Transitions in each direction highlight the challenges and imprecisions in predicting long-term neurologic abilities at the time of hospital discharge following an OHCA.
Limitations of the data include: information was obtained by retrospective chart review, lack of information on baseline neurologic status, differences in the emergency medical systems and ICU care provided over the last 40 years, and shortcomings inherent in using the PCPC scale as the measure of neurologic function. The PCPC, as acknowledged by the authors, is a gross and somewhat subjective scale of neurologic functioning, especially when determined by retrospective chart review. The PCPC scores of 1 and 2 were considered favorable outcomes in this study, but each PCPC grouping may encompass a fairly wide range of neurologic and functional status., In addition, a patient with pre-existing brain injury and neurologic impairments resulting in a PCPC ?3 at baseline cannot be expected to attain a PCPC score of 1 or 2 at hospital discharge despite an excellent resuscitation with return to baseline neurologic and functional status. Therefore, many studies include patients with no change in PCPC score as “favorable neurologic outcome.”
The broad range of normal developmental stages in childhood further complicates neurologic status assignment on scales like the PCPC, especially for young children. This lack of precision of the PCPC has been evaluated by comparing the scale to more specific neuropsychological tests. While the mean PCPC scores are associated with the means from standardized psychometric tests of neurologic functioning, the variability of the neuropsychological measures within each PCPC category is quite large.
Recently, Suominen and colleagues evaluated long-term neurocognitive outcomes in a small cohort of children a median of 8 years after OHCA due to drowning. Most of the children (8/11) categorized as normal (POPC 1) at hospital discharge had normal IQ tests at follow-up; however, 3/11 had ongoing memory or executive function impairments. Of the four children with a POPC of 2 at hospital discharge, one was normal, two had minor cognitive deficits, and one had major neurologic impairments. Of the five patients with POPC ?3 at hospital discharge, one improved to minor neurologic dysfunction, but the other four continued to have the major neurologic dysfunction exhibited at hospital discharge. In addition, van Zellem and colleagues described long-term neurologic outcomes of 43 children with OHCA or in-hospital cardiac arrest. They found deficits in IQ with a mean score of 87.3 with deficiencies mainly in visual motor processing and memory.
The study by Michiels and colleagues provides some comfort about the long-term neurologic outcome of children who survive to discharge with favorable neurologic outcomes following OHCA, but simultaneously raises concerns. Contrary to commonly held beliefs, neurologic functioning can, and does, change over time. With this new information, we now have the responsibility to more clearly define the long-term functional, neurocognitive, neurobehavioral and health-related quality of life profiles of these children, and to identify and characterize those who improve beyond our early expectations., , What you see on hospital discharge is not always what you get.
None of the authors have any conflicts of interest to disclose.