Bathtub Drowning: Unintentional, Neglect, or Abuse

Medicine and Health Rhode Island, Dec 2003 by Alpert, Brad

In the United States, drowning is the second leading cause of death due to injury in children younger than 15 years of age. It is defined as death from suffocation within 24 hours of submersion in water: victims of near drowning survive for at least 24 hours. About 8% of all drownings occur in bathtubs. In 1999 there were 88 unintentional bathtub drownings in children under 5 years of age in the United States. Forty were under one year of age (1.0:100,000) and 48 ages one through four (0.3:100,000).14 Bathtub drowning is rare in older children; most result from seizures. As many as 8% of all submersion injuries in children younger than 5 years of age are reported to be due to abuse.1

The percentage of bathtub submersion injuries that have been reported to be due to abuse or neglect has varied from 5 to 95%. Several factors contributed to the variability. 1) The criteria used to diagnose maltreatment were not uniform. 2) Suspicious elements in the history were often not recognized or utilized in order to determine causation. 3) The pathophysiology of hyoxic-ischemic brain injury was not considered. 4) Mortality and morbidity data related to submersion time in accidental drowning was not utilized to assist in determining the veracity of the history.

The same principles used to evaluate other forms of physical abuse or neglect should be applied to bathtub submersion injuries; however, this has not been done consistently in the published cases. Several elements in a history should raise concerns for the possibility of abuse: 1) A history of trauma that is inconsistent with an objectively observed injury revealed by physical examination, imaging, or laboratory studies. 2) A history of minor or no trauma in a child with extensive injury. 3) A history that changes over time. 4) A history of self-inflicted trauma that is incompatible with the child's development. 5) The caregiver ascribes blame for a serious injury to a young sibling or playmate. 6) There is a delay in seeking medical treatment.

There is no universally accepted definition of neglect that is unequivocal and quantitative. However, the possibility of neglect should be considered when the caretaker fails to provide for the basic needs of a child. In the spectrum of childcare, it is difficult to determine exactly where less-than-ideal care becomes neglect; however, some considerations are germane: 1) Did the caretaker fail to do what a reasonable person would do? 2) Has the caretaker been responsible for prior abuse or neglect? 3) Did a lack of intelligence or knowledge contribute to the event? 4) Is there evidence for intentionality?

In most of the cases of bathtub drowning, evidence of contemporary or past maltreatment was required to diagnose the mechanism of submersion as non-accidental. This is not true for other forms of severe abuse. In cases of abusive head trauma, there is often only evidence of an acute head injury without associated findings, such as skeletal fractures or bruises. It is likely that many cases of bathtub drowning were misclassified as accidental on this basis.

The pathophysiology of hypoxic-ischemic brain injury and the relationship between submersion time and outcome in unintentional drowning were not used to evaluate the veracity of the history provided by the caretaker. In animal studies, it takes 3 to 4 minutes of submersion for circulatory failure to supervene from myocardial hypoxia. Although the time required for complete anoxia to cause irreversible CNS injury is uncertain, it is likely to be on the order of 3 to 5 minutes.15 Child victims of submersion of five minutes or less have a greater than 90% probability of survival with minimal or no brain damage.1 Similar information was found in a report from the US Consumer Product Safety Commission.2 However, many cases in the literature were classified as accidental when the submersion lasted for a very brief period.

LITERATURE REVIEW

Pearn and Nixon3 first reported submersion injury as a form of child maltreatment in the medical literature in 1977. They reported on two children, a 3-year 7-month old girl and a 14-month-old boy, victims of intentional near-drowning. The authors speculated that intentional submersion injuries were missed, "because there is no specific trauma apparent, such as the more readily discernible and interpretable spiral fractures." However, in the subsequent literature this distinction was lost. Most studies required additional evidence of abuse or neglect to classify the submersion as intentional.

Pearn and Nixon4 also reported 19 consecutive bathtub submersions of children. Sixteen were younger than two years old. They identified only one case to be non-accidental. However, there was acute parental disharmony with domestic upheaval at the time of the incident in 85% of the cases. The median depth of water in the bathtub at the time of the event was 8 inches (range, 2 to 14 inches); of the 8 children who died, the median submersion time was only 5 minutes (range, 3 to 20 minutes). The domestic violence, probable excessive water depth, and relatively short submersion times suggest that maltreatment was greatly under-diagnosed.