Background and Aims Hypoxic Ischemic Encephalopathy (HIE) following perinatal asphyxia in term neonates is associated with long term neurological sequelae or demise. The aim of this systematic review was to investigate the prognostic value of currently used clinical tests in neonatal patients with HIE.
Methods MEDLINE, EMBASE, Central and CINAHL were searched until November 2011. Studies were included if they: (1) concerned infants with a gestational age ≥ 36 weeks suffering perinatal asphyxia and HIE; (2) evaluated prognostic tests in either cooled or non-cooled patients; (3) reported on neurodevelopmental outcome results at a follow up age ≥ 18 months. Study selection, assessment of methodological quality, and data extraction was performed by three independent reviewers. Pooled sensitivities and specificities of investigated tests were calculated when possible.
Results Included in the analysis were 29 studies describing 13 different prognostic tests conducted 1631 times in 1306 term neonates. Investigated tests comprised a range of imaging modalities, neurophysiological tests and clinical neurological exams. Most promising neurophysiology tests (first week of life) were: aEEG (sens. 0.93, [95%CI 0.78–0.98]; spec. 0.90 [0.60–0.98]); EEG (sens. 0.92 [0.66–0.99]; spec. 0.83 [0.64–0.93]) and VEP (sens. 0.90 [0.74–0.97]; spec. 0.92 [0.68–0.98]).
Conclusions The available evidence suggests an important role for aEEG, EEG, and VEP. Given the heterogeneity of the tests’ performance and outcomes studied, accurate predictions of long term outcomes in these critically ill neonates await the results of well designed large prospective studies that evaluate the best possible combination and timing of diagnostic tests.