OBJECTIVES: The goals were (1) to determine the prevalence of occult abdominal trauma (OAT) in a sample of children with suspected physical abuse, (2) to assess the frequency of OAT screening, and (3) to assess factors associated with screening.
METHODS: Charts of children evaluated for abusive injury were identified through a search of hospital discharge codes. Identified charts were reviewed to determine whether OAT screening occurred. Data on results of screening tests, abusive injuries identified, family demographic features, and characteristics of the emergency department visit were collected.
RESULTS: Screening occurred for 51 (20%) of 244 eligible children. Positive results were identified for 41% of those screened and 9% of the total sample; 5% of children 12 to 23 months of age had OAT identified through imaging studies. Screening occurred more often in children presenting with probable abusive head trauma (odds ratio [OR]: 20.4 [95% confidence interval [CI]: 3.6–114.6]; P < .01), compared with those presenting with other injuries. Consultation with the child protection team (OR: 8.5 [95% CI: 3.5–20.7]; P < .01) and other subspecialists (OR: 24.3 [95% CI: 7.1–83.3]; P < .01) also increased the likelihood that OAT screening would occur.
CONCLUSIONS: Our findings support OAT screening with liver and pancreatic enzyme measurements for physically abused children. This study also supports the importance of subspecialty input, especially that of a child protection team. Although many identified injuries may not require treatment, their role in confirming or demonstrating increased severity of maltreatment may be critical.
Abusive abdominal trauma is the second leading cause of death among physically abused children and may lead to significant morbidity among survivors.1,2 It may be difficult to diagnose, however, and even serious abdominal trauma may be missed.
In 1992, Coant et al3 described a series of physically abused children who were screened for occult abdominal trauma (OAT) through measurement of transaminase and pancreatic enzyme levels. Of the 49 children screened, 4 had elevated transaminase levels, and 3 of the 4 had occult liver lacerations diagnosed through abdominal computed tomography (CT). Influenced in part by the findings of Coant et al,3 physicians evaluating children for suspected physical abuse increasingly began to screen for OAT. Child abuse experts began recommending OAT screening, with a recommendation in an American Academy of Pediatrics policy statement on the evaluation of fractures suggesting physical abuse.4–6
Ludwig,4 in a review of visceral injury in abuse, provided a strong justification for OAT screening. He noted that abdominal injury may be overlooked because of young children's limited verbal skills, delayed symptoms, low abdominal muscle tone, and limited bruising and physicians' focus on other, more-overt injuries. He argued that even serious abdominal trauma may be overlooked.
Children with abusive abdominal injury seem to have higher mortality rates than children with nonabusive injuries of similar severity,7 and diagnostic delay may contribute to poor outcomes.8–12 In addition, delayed diagnosis of abusive abdominal injury may delay reporting to child protective services and police if other injuries are not clearly abusive. When the cause of an injury is ambiguous, the presence of associated injuries may help clarify the cause as abuse. This, in turn, may lead to life-saving interventions, such as placing the child in a safe home environment.
Although child abuse experts have recommended OAT screening for children with suspected abuse,4–6 OAT screening still seems to be sporadic. Furthermore, the low incidence of overt abusive abdominal trauma (3 cases per 1 million children) identified in 1 study13 has raised the question of whether the 6% to 8% rate of OAT found in the study by Coant et al3 is generalizable to other populations of children. This retrospective study was conducted to examine the rate of OAT among children with suspected physical abuse. A second objective was to identify characteristics of the child, family, and medical assessment that were associated with screening practice. On the basis of the epidemiological features of other abusive injuries, we hypothesized that screening would occur more often among children who were young, were members of a minority, were insured through Medicaid, and had more-severe injuries. We also hypothesized that screening would occur less often when the emergency department (ED) was busy and when subspecialty consultation was not provided.
Before initiation of this research, the protocol was submitted to our institutional review board and received an exemption from full review. All medical records from the University of Maryland Medical Center were searched to identify children 0 to 5 years of age who were seen in the pediatric ED and were diagnosed as having definite or possible physical abuse, but without suggestion of abdominal trauma, between January 1, 1997, and December 31, 2005. Abusive injuries primarily included bruising, abrasions, burns, falls, fractures, and/or head trauma. Children were identified by using International Classification of Diseases, Ninth Revision (ICD-9) codes and external cause of injury codes (E codes) for child abuse (ICD-9 code 995.5 and E codes 960–969).
To identify physically abused children who were not given child abuse diagnostic codes, all charts of children seen in the ED because of injuries also were reviewed. If the ICD-9 code, E code, or clinical diagnosis did not clearly indicate whether the injury was abusive versus noninflicted, then the record was reviewed by ≥1 investigator for clarification of the nature of the injury. Charts with any notation of reports to child protective services because of suspected physical abuse were added to the sample. Children with history and/or physical examination findings suggesting abdominal trauma, regardless of the cause, were excluded. Children who died in the ED also were excluded, because an autopsy would eliminate the need to screen for OAT.
Identified charts were reviewed to determine whether screening for OAT was conducted and, if so, which specific tests were performed and what results were obtained. Additional data included all injuries, history and symptoms at presentation, studies performed (eg, skeletal survey, head CT, abdominal CT, or ultrasonography), and subspecialist consultations. The status of the ED attending physician (faculty member or moonlighter) was noted, as were the time of day and year of presentation. Demographic information, including age, race/ethnicity, gender, and insurance status, was collected.
OAT screening tests reviewed included measurements of liver transaminase (alanine aminotransferase [ALT] and aspartate aminotransferase [AST]) and pancreatic enzyme (amylase and lipase) levels, assessment of urine for occult blood (dipstick and microscopic analysis), and assessment of stool for occult blood. Screening was considered to have occurred if ≥1 screening test was performed. In order not to miss any positive screening test results, we established somewhat-low threshold values for positive screening test results. Test results considered positive included ALT levels of ≥70 IU/L, AST levels of ≥80 IU/L, amylase levels of ≥90 IU/L, lipase levels of ≥50 IU/L, urine dipstick findings of ≥3+ blood, urine microscopic analysis findings of ≥20 red blood cells per high-powered field, and positive stool hemoccult findings.
Charts of children with positive OAT screening results were examined to determine whether any additional testing (eg, abdominal CT or ultrasonography) had been performed to confirm or to exclude abdominal trauma. The results of those tests were recorded.
Years of presentation were dichotomized into 1997–2001 versus 2002–2005, because there was a large increase in the rate of screening between 2001 and 2002. Presentation times were dichotomized into evening presentation (4:00 pm to 11:00 pm) versus nonevening presentation (all other times), because 4:00 pm to 11:00 pm is often the busiest time in the ED.
In data analyses, OAT screening was the primary dependent variable and was dichotomous; screening occurred if ≥1 screening test was performed. Characteristics of the sample were described by using means, medians, frequencies, and proportions. Bivariate analyses included t tests and χ2 tests, with Mann-Whitney U tests being used for nonnormal continuous variables.
Logistic regression was used for the multivariate analysis to identify factors predictive of OAT screening. Independent variables that were included in the multivariate analysis were those that were significant in bivariate analyses. A variable for subspecialty consultation was created for the multivariate analysis and was considered positive if any subspecialist (other than the child protection team [CPT]) provided consultation. CPT consultation was retained as a variable because we were interested in the specific effect of CPT consultation. Significant associations between types of injuries (eg, abusive head trauma and fractures), between injuries and CPT consultations or other consultations, and between CPT consultations and other consultations were identified. Therefore, separate models were developed for each injury variable and each consultation variable. Models were validated by using the technique described by Hosmer and Lemeshow.14
A total of 244 children presented to the ED with possible abusive injuries during the study period. Of those, 65% were male, 42% were <1 year of age, 81% were black, and 87% were insured through Medicaid (Table 1). One half of the children (n = 122) presented with bruises, although 30% of those children also had other injuries. Seventy children presented with fractures, and 5% presented with probable abusive head trauma. Twenty percent of caregivers had no explanation for their child's injuries.
Approximately 20% of children (n = 51) had ≥1 screening test for OAT performed (Table 1 and Fig 1). Although 21 of the 51 children who underwent screening had positive screening test results, only 9 underwent confirmatory testing through abdominal CT and/or ultrasonography. Five children (10% of those screened; 2% of the total sample) had injuries identified through abdominal CT and/or ultrasonography (specific findings are shown in Table 2). Among children 12 to 23 months of age, 5% of the total sample had injuries identified through abdominal imaging. Imaging findings often did not clearly indicate trauma, and several identified injuries were unrelated to the positive screening test results (Table 2). Possible splenic trauma was identified in 2 children, whereas adrenal hemorrhage and possible lung contusion were found in 2 other children. Of the 5 children with ALT levels of >250 IU/L and/or AST levels of >450 IU/L, 4 had evidence of intraabdominal injury on CT or ultrasound scans and 3 others had evidence of liver injury, which provides positive predictive values of 60% to 80%.
Twelve children with positive screening test results did not undergo evaluation through CT or ultrasonography. Eight of the 12 had only mildly elevated transaminase or lipase levels (ALT levels of ≤120 IU/L, AST levels of <130 IU/L, and/or lipase levels of ≤80 IU/L). One child with significantly elevated transaminase levels and urine dipstick findings of 3+ blood had anoxic brain injury. Three additional children had microscopic hematuria; 2 of these children had specimens collected through a urine bag. The method of collection for the third child was not documented in the chart.
Occurrence of OAT screening was not associated with most of the demographic variables examined, including race, gender, and insurance status (Table 3). However, children <18 months of age were less likely to be screened than were older children (11% vs 30% screened; P < .01). Children who presented in the evening (between 4:00 pm and 11:00 pm) were screened less often than were children who presented at other times of day (10% vs 25% screened; P < .01) (Table 4).
CPT, surgery, neurosurgery, or ophthalmology consultations all increased the likelihood of OAT screening (Table 4). Children who had a skeletal survey or head CT performed were more likely to receive OAT screening than were those who did not undergo these radiologic tests. Screening occurred more frequently after 2001, compared with before 2001 (39% vs 14%; P < .01).
In multivariate analysis, several variables predicted OAT screening (Table 5). Screening occurred more often for children presenting with probable abusive head trauma (odds ratio [OR]: 20.4 [95% confidence interval [CI]: 3.6–114.6]; P < .01), compared with those presenting with other injuries. Subspecialty consultation from the CPT (OR: 8.4 [95% CI: 3.5–20.8]; P < .01) and from other subspecialists (OR: 24.3 [95% CI: 7.1–83.3]; P < .01) also increased the likelihood that OAT screening would occur. Screening occurred more often in 2001–2005, compared with earlier years (OR: 3.2 [95% CI: 1.5–7.3]; P < .01) and occurred less often during peak ED activity (OR: 0.4 [95% CI: 0.1–0.9]; P = .03).
Of the 244 children with likely abusive injuries in our study, 51 (21%) were screened for OAT, and 21 had ≥1 positive screening test result for OAT. This represents 41% of all children screened and at least 9% of all children with abusive injuries. These are conservative estimates, with the assumption that no OAT was present among children who were not screened. Our rate of 9% is similar to findings in other studies. For example, Coant et al3 found positive screening results for 8% of children with suspected child abuse, and Isaacman et al15 examined children with noninflicted trauma and found occult abdominal injury in 6%. Therefore, OAT is hardly rare in the context of possible physical abuse.
When examining the rate of occult injury confirmed through abdominal CT or ultrasonography, we found that 10% of children screened had OAT, accounting for 2% of all children with physical abuse and 5% of toddlers. These rates are comparable to those of other studies of children with both inflicted (6%) and noninflicted (4.8%) trauma.3,15 Our findings indicate that at least 2 of every 100 children <5 years of age presenting with possibly abusive injuries also have occult abdominal injury and 1 in 20 toddlers may have occult abdominal injury.
For a number of reasons, our rates of OAT can only be considered estimates. First, our data and those of other researchers suggest that abdominal ultrasonography and CT are not true standard methods and may miss some abdominal injuries. Even if radiologic testing was considered the standard, the majority of children did not have ultrasonography or abdominal CT performed. Therefore, the sensitivity and specificity of the laboratory tests could not be determined. Furthermore, some of the children with abnormal screening test results did not undergo radiologic testing; therefore, we were unable to confirm the presence of abdominal injury. Although most children in this group had only mildly elevated laboratory results, this does not eliminate the possibility of abdominal injury. The utility of both screening and diagnostic tests varied according to the abdominal organ of interest, as discussed below.
Although several authors found liver transaminase levels to be accurate predictors of hepatic injury,15–18 with sensitivity of 93% to 100% and specificity of 53% to 100%, a more-recent publication indicated a much lower sensitivity of only 53%.19 Although we could not calculate sensitivity or specificity, we did find these screening tests to have reasonable predictive value. Our positive predictive value of 60% to 80% is higher than that of 43% in the study by Isaacman et al.15 Although we did not find any obvious liver lacerations, findings such as ascites surrounding the liver and coarse echogenicity of the liver strongly suggest trauma, particularly in the context of elevated transaminase levels.20 Our high positive predictive value supports the recommendation to perform screening for children being evaluated for suspected physical abuse.
Although 3 children had markedly elevated pancreatic enzyme levels and all had CT or ultrasonography performed, we did not find any obvious pancreatic lacerations. This finding might be construed as indicating that pancreatic enzyme levels are not predictive of pancreatic injury. However, other studies indicated that identification of pancreatic trauma through CT might be particularly difficult.21–23 Therefore, it is likely that some pancreatic injuries were present despite negative CT results. This finding suggests that our estimates of OAT might be higher than our conservative estimate of 2% noted above.
We had hoped that stool hemoccult testing would screen adequately for intestinal injury. Unfortunately, testing was performed for only 2 children, which made it impossible to assess its utility. Given the possibility of bowel trauma, it seems prudent to perform this easy screening test, although its sensitivity in other studies ranged only from 25% to 60%.24,25 Results from several previous studies indicated that hematuria also might be an accurate predictor of renal injury.15,26–28 Unfortunately, the 3 children identified with hematuria did not undergo radiologic testing to evaluate possible renal or bladder injury. Optimal practices should include further evaluation. Given the ease and low cost of these 2 tests, it seems reasonable to include them in screening for children with suspected physical abuse.
Several children in our study had traumatic injuries, such as lung contusion and splenic trauma, that could not have been identified through any specific screening test. These findings indicate that many children with abusive injuries also may have occult injuries that cannot be identified through noninvasive screening tests. The decision to search for such occult injuries must balance the risks of missing an injury (eg, bleeding, sepsis, death, or return to an abusive caregiver) with the risks of radiation, sedation, and oral contrast agent administration required for abdominal CT, as well as the cost of CT or ultrasonography.
We did not identify disparities in OAT screening according to race, gender, or insurance status, findings that were reassuring, given previous studies demonstrating different rates of screening for abusive head trauma and occult skeletal injury according to race29,30 and differences in the diagnosis of abuse according to social class.31 However, limited racial and socioeconomic variability in our sample made it difficult to examine differences.
We expected rates of screening to be higher for more-severe injuries such as fractures and abusive head trauma. This was the case for the most part in our bivariate analyses. However, only abusive head trauma remained a predictor of screening in our multivariate analysis. It is likely that physicians considered abusive head trauma to be a more-severe form of abuse, compared with the other abusive injuries.
Subspecialty input clearly played a role in the decision to perform OAT screening. This might have reflected the severity of children's injuries; children with more-severe injuries were more likely to have subspecialty and CPT consultations and were more likely to be screened because of the severity of injury. However, it also might be that subspecialists were more aware of the possibility of occult abdominal injury, compared with ED physicians. It also is possible that surgical subspecialists were following Advanced Trauma Life Support protocols, which recommend screening even in the absence obvious signs or symptoms of abdominal injury. In contrast, pediatric ED physicians might have been more focused on the overt injuries and were not classifying these children as potentially having multiple traumas.
Screening occurred less often during peak ED hours (4:00 pm to 11:00 pm). This finding suggests that physicians screen more often when they have more time to think about patient evaluation and management and they forget to screen when they are busy. Management pathways or computerized order templates could prompt physicians to screen when they might otherwise forget.
There were a number of limitations to this study. Because it was a retrospective chart review, we could not guarantee that children would be screened for OAT or that children with positive screening results would undergo CT or ultrasonography. Therefore, it is probable that some children with OAT were missed. This was a particular problem for the 3 children with hematuria who did not undergo abdominal imaging, because several studies have shown that hematuria is a good marker for intraabdominal trauma among children with noninflicted injury.15,26–28 Therefore, we have presented conservative estimates of the proportions of positive screening results, assuming that none of the unscreened children had OAT and noting the minimal proportion of children with OAT. Even with these conservative estimates, the proportion of physically abused children with OAT was large enough to warrant screening, at least for children <3 years of age.
A second limitation was the small number of children with positive OAT screening test result and/or abdominal CT or ultrasound findings. The small numbers precluded the identification of factors associated with the presence of occult abdominal injury. Future prospective studies may better identify these factors and may provide more-specific criteria for OAT screening.
The abdominal injuries in our study were not associated with significant morbidity. However, the presence of multiple injuries is potentially a marker for more-serious abuse, with important implications for children's health and safety.
Our findings support the recommendation of Coant et al3 for OAT screening with liver and pancreatic enzyme measurements for physically abused children. Additional studies are needed to establish the utility of screening with urinalysis and stool hemoccult testing. This study also supports the importance of subspecialist input, especially that of a CPT, in the medical evaluation of suspected physical abuse. Although many identified injuries may not require treatment, their role in confirming abuse or demonstrating the increased severity of maltreatment may be critical in protecting children from further abuse.
Support for this work was provided, in part, by the University of Maryland General Clinical Research Center Grant M01 RR16500, General Clinical Research Centers Program, National Center for Research Resources (NCRR), NIH. The authors would like to thank Drs. Amaly Rahman, Judy Huang, and Raj Ravula as well as Ms. Michelle Thomas for their assistance with chart review and data abstraction.
- Accepted July 9, 2009.
- Address correspondence to Wendy Gwirtzman Lane, MD, MPH, Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, 660 West Redwood St, Baltimore, MD 21201. E-mail:
Financial Disclosure: The authors have indicated they have no financial relationships relevant to this article to disclose.
What's Known on This Subject:
Abusive abdominal trauma may be difficult to diagnose; even serious abdominal injury may be missed. Screening for OAT has been recommended on the basis of 1 study with 53 children. However, these findings have not been reproduced.
What This Study Adds:
This study confirms high rates of OAT among physically abused children and identifies toddlers as being particularly vulnerable. It also demonstrates the importance of consultation with a CPT and other subspecialists to ensure thorough evaluation of children with suspected abuse.
- ↵Schnitzer PG, Ewigman BG. Child deaths resulting from inflicted injuries: household risk factors and perpetrator characteristics. Pediatrics.2005;116 (5). Available at: www.pediatrics.org/cgi/content/full/116/5/e687
- ↵Coant PN, Kornberg AE, Brody AS, Edwards-Holmes K. Markers for occult liver injury in cases of physical abuse in children. Pediatrics.1992;89 (2):274– 278
- ↵Ludwig S. Visceral manifestations of child abuse. In: Reece RM, Ludwig S, eds. Child Abuse: Medical Diagnosis and Management. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2001:157–176
- Jenny C. American Academy of Pediatrics, Committee on Child Abuse and Neglect. Evaluating infants and young children with multiple fractures. Pediatrics.2006;118 (3):1299– 1303
- ↵Alexander RC, Levitt CJ, Smith WL. Abusive head trauma. In: Reece RM, Ludwig S, eds. Child Abuse: Medical Diagnosis and Management. 2nd ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2001:47–80
- ↵Trokel M, DiScala C, Terrin NC, Sege RD. Blunt abdominal injury in the young pediatric patient: child abuse and patient outcomes. Child Maltreat.2004;9 (1):111– 117
- ↵Hosmer DW, Lemeshow S. Applied Logistic Regression. New York, NY: Wiley; 1989
- ↵Isaacman DJ, Scarfone RJ, Kost SI, et al. Utility of routine laboratory testing for detecting intra-abdominal injury in the pediatric trauma patient. Pediatrics.1993;92 (5):691– 694
- Hennes HM, Smith DS, Schneider K, et al. Elevated liver transaminase levels in children with blunt abdominal trauma: a predictor of liver injury. Pediatrics.1990;86 (1):87– 90
- Copyright © 2009 by the American Academy of Pediatrics