Child abuse is a significant problem in the United States with approximately four children dying of abuse every day, most of whom are younger than 4 years. Additionally, 1300 children are presumed to die each year following abusive head trauma. Rapid identification of non-accidental head trauma helps child-protection workers and the police protect children and apprehend and prosecute abusers.
For many years, the presence of retinal hemorrhages in an infant with a neurologic injury was thought to be diagnostic for shaken baby syndrome (SBS), and frequently these hemorrhages were the only physical finding suggestive of abuse. However, the literature supporting this assumption was lacking, and many have suggested that cardiopulmonary resuscitation and increased intracranial pressure could also cause retinal hemorrhages. In 1997, Odom et al helped dispel the notion that cardiopulmonary resuscitation could cause the types of retinal bleeding seen with SBS. The recent article by Binenbaum et al, which appeared in the August issue of Pediatrics, continues this process of validation by examining the presence of retinal hemorrhages in children with non-traumatic causes of increased intracranial pressure (ICP).
In this work, the authors recruited subjects between the ages of 1 and 17 years who were undergoing lumbar punctures. Children with a history of head trauma, indwelling ventricular catheters, lumbar drains, or brain tumors were excluded. Opening pressure (OP) measurements were obtained. OP was defined as the highest pressure sustained for 10 seconds. All subjects also underwent a dilated funduscopic examination performed by a pediatric ophthalmologist no later than 96 hours after the lumbar puncture; 93% were completed within 48 hours.
Of the 100 subjects who met inclusion criteria, 32 had an OP between 20 and 28 cm H2O, and 68 had an OP >28 cm H2O. The most common diagnosis was idiopathic intracranial hypertension, but other diagnoses included infectious disease, rheumatologic or demyelinating disease, and venous thrombosis. Optic disc swelling was noted in 74 children. Sixteen subjects had splinter optic disc hemorrhages or superficial intraretinal hemorrhages, as well as moderate to severe optic disc swelling. Retinal hemorrhages were not seen in other areas (e.g., retinal periphery), not even in one case of papilledema causing severe vision loss.
The authors claim that these findings are consistent with anecdotal experiences of other pediatric ophthalmologists who routinely perform funduscopic exams on children with increased ICP. However, they also claim that the hemorrhages seen in this study are fundamentally different from the severe hemorrhagic retinopathy typically described with SBS, which are often multilayered and deeper, "dot-and-blot" intraretinal hemorrhages. The authors also comment on the relative infrequency of disc swelling (<9% of cases) seen with head trauma compared to the study subjects.
This study's strengths lie in the number of subjects enrolled and in the fact that pediatric ophthalmologists performed the funduscopic exams. The authors acknowledged the weaknesses, which are not insignificant. First, the ICPs in these subjects were presumably chronic in nature as opposed to the circumstances seen with an acute head injury. The pattern of hemorrhage seen in acute injuries is primarily preretinal and vitreous and is, again, different from the patterns seen with SBS (or Terson syndrome). Secondly, the subjects in this study were older than those seen with SBS, but, as the authors comment, because of their open sutures and fontanelles, infants are less likely to have papilledema and associated retinal hemorrhage.
Critical care physicians, child abuse specialists, and other medical professionals are often asked to testify in court about the nature of injuries, particularly in cases of non-accidental head trauma, and must be able to support their conclusions with good medical evidence. While there is not an exhaustive supply of literature supporting the notion that significant retinal hemorrhages are diagnostic of SBS, this work provides more affirming evidence.
This Concise Critical Appraisal is authored by SCCM member Daniel E. Sloniewsky, MD. Each installment highlights journal articles most relevant to the critical care practitioner. Daniel Sloniewsky is an associate professor in the Department of Pediatrics at the Stony Brook Long Island Children's Hospital in Stony Brook, NY, where he is board certified in pediatrics and pediatric critical care. He completed his fellowship training at Children's Memorial Hospital and Northwestern University in Chicago. His major interests are in acute pediatric pulmonary disease, transfusion medicine and ethics. He is also actively involved in resident education, Pediatric Advanced Life Support and Pediatric Fundamental Critical Care Support instruction.