JOURNAL CLUB

JOURNAL CLUB

DIGESTS AND COMMENTARIES BY MICHAEL G. BURKE, MD

Abusive head trauma often unrecognized

A retrospective review of cases of head trauma in children younger than3 years shows that physicians often do not initially recognize head injuriescaused by abuse. In 54 (31.2%) of 173 children eventually identified ashaving abusive head trauma, the diagnosis had been missed on first presentation.In children with missed abusive head injury, diagnosis took a mean of 2.8visits to the physician and seven days after first evaluation. A comparisonof missed cases with those not missed revealed several significant differences:

• Children in missed cases were much younger than those diagnosed on the first visit to the physician. Their mean age was 180 days compared with 278 days in recognized cases.
• Children in missed cases were significantly more likely to be white than from a racial minority. In white children, 43 (37.4%) of 115 cases were missed; in minority children the comparable figure was 11 (19%) of 58.
• Abusive head trauma was more likely to be missed when both parents lived with the child. Of 92 cases in intact families, 37 (40.2%) were missed compared with 14 (18.7%) of 75 cases where the mother and father were not living together.
• As might be expected, children with more severe symptoms (coma, compromised breathing, seizures, or facial bruises) were more likely to be recognized as abused at the first visit than were children with mild symptoms, such as irritability or vomiting (Jenny C et al: JAMA 1999;281:621).

Commentary: The authors estimate that if a child with abusivehead injury doesn't have seizures, abnormal respiration, visible facialor scalp injury, or separated parents, the chance that the physician willrecognize abuse on the first encounter is 20%. Acknowledging that this diagnosisoften is subtle, the authors offer this advice to improve chances of earlydiagnosis:

• Think of the possibility of abusive head injury in any child with nonspecificfindings.
• Be suspicious of abrasions and bruising, especially in children too young to pull to stand.
• In doing a lumbar puncture, look for xanthochromia as an indicator of old blood from previous trauma.
• Ask a pediatric radiologist to interpret suspicious X-rays and CT scans in potential child abuse cases.

Deciding when to X-ray head injuries

A retrospective study of children younger than 24 months evaluated forhead injury suggests which of these children are most likely to have complications.Of 278 children presenting to an emergency department for evaluation ofa head injury, 163 (59%) were younger than 12 months and 115 (41%) were12 months or older. Most of the injuries were caused by falls. Overall incidenceof skull fracture or intracranial
injury was 18%.

Other than focal neurologic abnormalities and depressed level of consciousness,which only a few patients exhibited, no single symptom or group of symptomscould reliably predict skull fracture or intracranial injury. Factors traditionallyassociated with complications of head trauma, such as loss of consciousness,vomiting, seizure, and behavioral change, were absent in 62% of childrenwith isolated skull fracture and 58% of children with intracranial injury.The presence of scalp abnormalities was associated with these injuries,however, as were a fall of more than 3 feet and being younger than 12 months.The child who fits this profile warrants imaging studies, investigatorsconcluded. Children who fallless than 3 feet, have no history of neurologicsymptoms, and have no scalp abnormalities are unlikely to have complicationsand may not require such studies--particularly if the child is older than12 months (Gruskin KD et al: Arch Pediatr Adolesc Med 1999;153:15).

Commentary: The authors seem hesitant about making recommendationsabout which children do and do not need imaging after head injury--and withgood reason. This is a retrospective study in which only 110 of 228 patientshad CT imaging and only 83 had skull films. We know that some children withintracranial aneurysm and skull fracture can present with few signs or symptoms,so the true incidence of significant injury may be higher than the 18% statedhere. The authors do describe a low-risk group of patients, but only 31of their patients fit in the group. This is a pretty small sample for establishinga guideline. Until these issues can be clarified, I will continue to refrainfrom criticizing emergency room doctors who choose to CT scan children withwhat may seem like minor head injury.

Thumbs up for combined hepatitis A/B vaccine

A combined pediatric vaccine against hepatitis A and B is safe and immunogenic,two studies in Canada show. The 180 children in whom the vaccine was testedwere divided into three groups: 1- to 6-year-olds and two groups of 6- to15-year-olds. All three groups received three doses of a combined vaccinecontaining 360 units of hepatitis A antigen and 10 mg of hepatitis B surfaceantigen administered at 0, 1, and 6 months.

One month after the second dose, all patients in all three groups hadseroconverted against hepatitis A virus. Seroconversion against hepatitisB virus was 98.8% at that time. After the third dose, all subjects wereseropositive for both components. Reactions were comparable to those followingadministration of two separate vaccines. Local and systemic reactions weremostly mild or moderate and resolved spontaneously. Only one serious adverseevent occurred after more than 500 doses of the combined vaccine, and itmost likely was caused by a concurrent viral infection (Diaz-Mitoma F etal: Pediatr Infect Dis J 1999;18:109).

Commentary: Unlike hepatitis B, hepatitis A does not cause a chroniccarrier state. It can occasionally cause fulminant liver failure, however.Despite availability of a vaccine, universal immunization against hepatitisA has not yet been recommended. Perhaps development of this combinationhepatitis A/B vaccine will provide the necessary "shot in the arm."

Growth and long-term growth hormone therapy

Short-term administration of growth hormone in short normal childrenis known to increase the growth rate and standard-deviation scores for height.Now a study shows that long-term administration of growth hormone in thesechildren produces similar long-term results: As adults, treated childrenare taller than children with idiopathic short stature who are not treated.A total of 80 children (57 boys and 23 girls)completed between two and 10years of growth hormone treatment--a weekly dosage of 0.3 mg per kilogramof body weight divided into either three times weekly or daily subcutaneousdoses--before reaching adult height. Although responses varied, 63 of the80 children (79%) had an adult height that was greater than predicted beforetreatment began. The difference between predicted and achieved heights wassignificantly greater in treated children than in untreated children, particularlyboys (Hintz RL et al: N Engl J Med 1999;340:502).

Commentary: These children underwent from two to 10 years of injectionsthree times a week to gain an average of about 2 inches in adult height,at costs ranging from $2,000 to $10,000 a year. Is it worth it?

Screening for psychosocial problems

Investigators assessed the feasibility of using the Pediatric SymptomChecklist (PSC) for routine psychosocial screening. Previous studies withsmall samples have shown the efficacy of the PSC for early detection inselected pediatric sites, but the checklist had not been assessed in diversesituations--different types of pediatric practices with different insurancereimbursement methods, located in a variety of geographic regions. Parentsof 21,065 children were asked to complete a brief questionnaire that includeddemographic information, history of mental healthservices, the 35-item PSC,and the number of pediatric visits within the past six months. Because ofthe following findings, researchers concluded that the PSC offers an approachto recognition of psychosocial dysfunction that is sufficiently consistentacross groups and locales to become part of comprehensive pediatric carein virtually all outpatient settings:

• Overall prevalence rates of psychosocial dysfunction as measured by the PSC--13% in school-age children and 10% in preschool children--were nearly identical to the rates that had been reported in several smaller samples.
• Consistent with previous findings, children from low-income families were twice as likely to be scored as dysfunctional on the PSC as children from higher-income families. Similarly, children from single-parent homes compared with two-parent families and children of families with a past history of mental health services had an elevated risk of psychosocial impairment.
• The overall rate of completed forms was 97%, which is well within an acceptable range. At least 94% of the parents in each sociodemographic subgroup completed the PSC form (Jellinek MS et al: Arch Pediatr Adolesc Med 1999;153:254).

Commentary: The PSC appears to be a simple, quick, accurate questionnairethat can be administered easily in a variety of office settings. It maybe the tool we need to identify children at psychosocial risk, even whenthey are seen in a busy pediatric practice. The question now is whetherwe are prepared to treat or refer the problems that we identify in 10% ofpreschoolers, 13% of school-age children, and up to 26% of children fromlow socioeconomic groups.

Also of note

Stethoscopes capable of transmitting RSV. Investigators evaluated whetherstethoscopes can transmit respiratory syncytial virus (RSV) by examiningthe virus's ability to survive in dried secretions on stethoscopes thatwere deliberately contaminated. They obtained fresh secretions from patientsknown to be infected with RSV, then inoculated the diaphragms of nine stethoscopesand allowed them to dry. Cultures showed that RSV survived for as long assix hours in the dried secretions. Polymerase chain reaction (PCR), a moresensitive technique than culturing, recovered virus after eight hours, butwhether the virus was infectious is unknown. In a second experiment, investigatorscultured three stethoscopes inoculated with RSV-containing secretions immediatelyafter the secretions dried. When they later wiped the stethoscopes witha single prepackaged alcohol swab, viral culture failed to recover RSV fromany of the three stethoscopes though PCR detected the virus on one (Blydt-HansenT et al: Pediatr Infect Dis J1999;18:164).

Neck rotation may be tied to SIDS. A histopathic study provides evidencethat infant neck extension or rotation can cause vertebral artery compressionleading to brain stem ischemia. This mechanism could explain some casesof sudden infant death syndrome (SIDS). During autopsy, investigators removedthe C1-C7 spinal column, together with a rim of skull base, from nine infantswho died from SIDS and 11 who died from other causes. In five infants theneck was extended and in nine it was rotated 90 degrees to the right beforefixation. Vertebral artery compression had occurred in three of the fivebabies with extended necks and three of the nine whose necks were rotated.The investigators concluded that vertebral artery compression caused bythe head movements used by an infant sleeping prone to clear its nose fromthe bedding could explain why the prone position is a major risk factorfor SIDS (Pamphlett R et al: Pediatrics 1999;103:460).