Saturday, 25 June 2011

SBS: Can a Short Fall Produce the Medical Findings of Shaken Baby Syndrome?

David L. Chadwick, MD

In a large number of cases infants with the findings of shaken baby syndrome are brought for care with a history from the caretaker that the change in the baby’s condition followed a short fall from a bed, couch, chair, counter or another item of household furniture. What is the chance that this history might be true under these circumstances?

Most child abuse pediatricians would answer that question with words to the effect that the probability of a life-threatening head injury resulting from a fall of less than 4 ½ feet is remote. It is also unlikely that even a long free fall of 10-20 ft. with a serious head injury would produce the severe eye findings that are usually a part of SBS. The language about probability takes its origin from the facts that a zero probability of any event cannot be proven without an infinite number of observations, but a huge anecdotal pediatric experience of short falls supports a conclusion that they are almost always benign. In addition, it has been difficult to document the numbers of short falls that are affecting infants and toddlers so the precise expression of probability that a scientist might like is still not in hand although we are moving closer to it. In Plunkett’s videotaped case epidural hematoma was not excluded; an undescribed surgical procedure preceded death (and the autopsy) in that case.

We can now state with some confidence that the probability of a fatal injury (with SBS pathology) resulting from a short fall of an infant or toddler cannot be greater than 1 per million children aged 0-5 yrs./year, and is likely to be less than that. This is a probability estimate based on population. An estimate based on numbers of short falls would be many times as large, but varied by age. Toddlers fall from ground level at a rate of about 4 times per day, and from low elevated surfaces about every other day. Infants fall much less frequently but may fall from a low elevated surface about 4-5 times in the first year after birth(1, 2).

The probability of short fall death could even be zero, although zero can only be proved in an eternity. Published, isolated case reports of short fall deaths can be found (3-5), and most depend on the statements of caretakers. Many of these statements are incorrect (6) All have some problem with validity as do the 13 cases that make up the deaths attributed to short falls by medical examiners in 5 years in California and which provide the one-in-a-million risk figure (7). That figure can be compared with the numbers of deaths of infants and young children in California attributed to homicide that provide a rate of about 30/million young children/yr. (7)

Ultimately, a caretaker’s statement about an event that occurred in a private setting cannot be objectively confirmed or contradicted.

Rare short fall deaths may occur with epidural hematomas (8) or with subdural bleeding caused by pre-existing medical conditions such as coagulopathies or arterio-venous malformations, but these can be excluded in most cases. Pre-existing brain abnormalities may also cause confusion although they are generally easily recognized.

The most important published medical experience about the effects of childrens’ short falls can be found in about 175 published articles that we have winnowed from among about 1500 total reviewed publications that have something to do with children and injuries and falls(9). A few of the 175 articles have been quoted frequently in past forensic discussions of this topic, such as the four papers that describe 560 cases of falls occurring in hospitals (10-13) without any serious consequences, and the Plunkett article that analyzes a database of playground injuries from the Consumer Product Safety Commission (14) but does not raise the probability of a fatal short fall to 1/million young children/yr. Most of the 175 articles are not usually cited in litigated cases. In particular, the articles that describe injuries in day car settings deserve more attention

The large body of literature combined with an analysis of better injury databases now enables us to provide the quantitative estimate of less than the one in a million figure cited above.

1. Kravitz H, Driessen G, Gomberg R, Korach A. Accidental falls from elevated surfaces in infants from birth to one year of age. Pediatrics 1969;44(5):Suppl:869-76.
2. Warrington SA, Wright CM, Team AS. Accidents and resulting injuries in premobile infants: data from the ALSPAC study. Arch Dis Child 2001;85(2):104-7
3. Hall JR, Reyes HM, Horvat M, Meller JL, Stein R. The mortality of childhood falls. J Trauma 1989;29(9):1273-5.
4. Denton S, Mileusnic D. Delayed sudden death in an infant following an accidental fall: a case report with review of the literature. Am J Forensic Med Pathol 2003;24(4):371-6.
5. Reiber GD. Fatal falls in childhood. How far must children fall to sustain fatal head injury? Report of cases and review of the literature. Am J Forensic Med Pathol 1993;14(3):201-7.
6. Chadwick DL, Chin S, Salerno C, Landsverk J, Kitchen L. Deaths from falls in children: how far is fatal? J Trauma 1991; 31(10):1353-5.
7. State of California DoHS. California Injury Data Online. In; 2006.
8. Schutzman SA, Barnes PD, Mantello M, Scott RM. Epidural hematomas in children. Ann Emerg Med 1993;22(3):535-41.
9. Chadwick DL, Bertocci G, Castillo E, Frasier L, Guenther E, Hansen K, et al. Annual Risk of Death Resulting From Short Falls Among Young Children: Less Than 1 in 1 Million. Pediatrics 2008;121(6):1213-1224.
10. Helfer RE, Slovis TL, Black M. Injuries resulting when small children fall out of bed. Pediatrics 1977; 60(4):533-5.
11. Levene S, Bonfield G. Accidents on hospital wards. Arch Dis Child 1991; 66(9):1047-9.
12. Lyons TJ, Oates RK. Falling out of bed: a relatively benign occurrence. Pediatrics 1993; 92(1):125-7.
13. Nimityongskul P, Anderson LD. The likelihood of injuries when children fall out of bed. J Pediatr Orthop 1987; 7(2):184-6.
14. Plunkett J. Fatal pediatric head injuries caused by short-distance falls. Am J Forensic Med Pathol 2001;22(1):1-12.

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