Validation of a clinical score to predict skull fracture in head-injured infants.

OBJECTIVES: To validate a previously derived clinical score that uses clinical signs to determine which head-injured infants are at risk of skull fracture. The clinical score is calculated on the basis of the patient's age, the scalp hematoma size, and the location of the hematoma, with a total value between 0 and 8. METHODS: We performed a prospective observational study of children younger than 2 years with blunt head trauma presenting to an urban pediatric emergency department. Among subjects who had head imaging performed (validation set), we assessed the utility of our clinical score to detect skull fracture and intracranial injury. RESULTS: In the 203 patients with imaging, 51 (25%) were diagnosed with skull fracture and 29 (14%) with intracranial injury. A clinical score of 4 or greater identified 90% (46/51) of patients with skull fracture with a sensitivity of 0.90 (95% confidence interval [CI], 0.78-0.96) and a specificity of 0.78 (95% CI, 0.70-0.84). A clinical score of 3 or greater identified 93% (27/29) of those with an intracranial injury with a sensitivity of 0.93 (95% CI, 0.76-0.99) and a specificity of 0.42 (95% CI, 0.35-0.50). A score of 3 or greater identified 100% of intracranial injury among asymptomatic patients. CONCLUSIONS: We have validated our clinical scoring system as an accurate way of determining an infant's risk of skull fracture. Whereas a clinical score of 4 or greater maximizes the trade-off between sensitivity and specificity for identifying skull fracture, a clinical score of 3 or greater may be preferable for detecting intracranial injury.

Cardiac troponin increases among runners in the Boston Marathon.

STUDY OBJECTIVE: Studies indicate that running a marathon can be associated with increases in serum cardiac troponin levels. The clinical significance of such increases remains unclear. We seek to determine the prevalence of troponin increases and epidemiologic factors associated with these increases in a large and heterogeneous cohort of marathon finishers. METHODS: Entrants in the 2002 Boston Marathon were recruited 1 to 2 days before the race. Data collected included demographic and training history, symptoms experienced during the run, and postrace troponin T and I levels. Simple descriptive statistics were performed to describe the prevalence of troponin increases and runner characteristics. RESULTS: Of 766 runners enrolled, 482 had blood analyzed at the finish line. In all, 34% were women, 20% were younger than 30 years, and 92% had run at least 1 previous marathon. Most runners (68%) had some degree of postrace troponin increase (troponin T > or = 0.01 ng/mL or troponin I > or = 0.1 ng/mL), and 55 (11%) had significant increases (troponin T > or = 0.075 ng/mL or troponin I > or = 0.5 ng/mL). Running inexperience (< 5 previous marathons) and young age (< 30 years) were associated with elevated troponins. These correlates were robust throughout a wide range of troponin thresholds considered. Health factors, family history, training, race performance, and symptoms were not associated with increases. CONCLUSION: Troponin increases were relatively common among marathon finishers and can reach levels typically diagnostic for acute myocardial infarction. Less marathon experience and younger age appeared to be associated with troponin increases, whereas race duration and the presence of traditional cardiovascular risk factors were not. Further work is needed to determine the clinical significance of these findings.

Identifying hospitalized infants who have bronchiolitis and are at high risk for apnea.

STUDY OBJECTIVE: Young infants with bronchiolitis are at risk for apnea. We seek to determine the rate of apnea in young infants with bronchiolitis and evaluate the performance of a predefined set of risk criteria for identifying infants at high risk for the development of apnea. METHODS: We identified a retrospective cohort study of patients treated in the emergency department (ED) of an urban pediatric tertiary care hospital from November 1995 to June 2000. All infants younger than 6 months who met our study definition of bronchiolitis and were admitted to the hospital were included. We developed, a priori, a set of risk criteria for identifying patients at high risk for apnea. Children were considered to be at high risk for apnea if (1) they were born at full term and were younger than 1 month, (2) they were born preterm (<37 weeks estimated gestational age) and were younger than 48 weeks postconception, or (3) the child's parents or a clinician had already witnessed an apnea episode with this illness before inpatient admission. Data pertaining to these risk criteria were collected from the ED physician's note. The primary outcome variable, the development of inhospital apnea, was assessed by review of the inpatient discharge summaries and medical records. RESULTS: Nineteen of 691 (2.7%; 95% confidence interval [CI] 1.7% to 4.3%) infants admitted with bronchiolitis developed apnea while hospitalized. All 19 patients with apnea were identified by our risk criteria (100% sensitivity; 1-sided 97.5% CI 82% to 100%). No patient classified as low risk subsequently developed apnea (100% negative predictive value; 1-sided 97.5% CI 99% to 100%). CONCLUSION: The rate of apnea among young infants hospitalized with bronchiolitis is low. Our clinical risk criteria successfully identified a low-risk group of infants whose risk of apnea is less than 1%.

The Boston Marathon Study: a novel approach to research during residency.

Resident physicians from a pediatric academic training program developed a hospital-wide research project in an effort to enhance their residency research experience. In this model, residents themselves assumed primary responsibility for each stage of a large prospective clinical research study. The project, which was integrated successfully into the residency program, enabled a large group of residents, with mentorship from a dedicated faculty member, to benefit from a structured clinical research experience while providing the flexibility necessary to meet the demands of a busy residency curriculum. Careful topic selection with a well-defined end point, faculty involvement, resident collegiality, and institutional support were factors identified by study leaders as central to the success of this model.

Hyponatremia among runners in the Boston Marathon.

BACKGROUND: Hyponatremia has emerged as an important cause of race-related death and life-threatening illness among marathon runners. We studied a cohort of marathon runners to estimate the incidence of hyponatremia and to identify the principal risk factors. METHODS: Participants in the 2002 Boston Marathon were recruited one or two days before the race. Subjects completed a survey describing demographic information and training history. After the race, runners provided a blood sample and completed a questionnaire detailing their fluid consumption and urine output during the race. Prerace and postrace weights were recorded. Multivariate regression analyses were performed to identify risk factors associated with hyponatremia. RESULTS: Of 766 runners enrolled, 488 runners (64 percent) provided a usable blood sample at the finish line. Thirteen percent had hyponatremia (a serum sodium concentration of 135 mmol per liter or less); 0.6 percent had critical hyponatremia (120 mmol per liter or less). On univariate analyses, hyponatremia was associated with substantial weight gain, consumption of more than 3 liters of fluids during the race, consumption of fluids every mile, a racing time of >4:00 hours, female sex, and low body-mass index. On multivariate analysis, hyponatremia was associated with weight gain (odds ratio, 4.2; 95 percent confidence interval, 2.2 to 8.2), a racing time of >4:00 hours (odds ratio for the comparison with a time of <3:30 hours, 7.4; 95 percent confidence interval, 2.9 to 23.1), and body-mass-index extremes. CONCLUSIONS: Hyponatremia occurs in a substantial fraction of nonelite marathon runners and can be severe. Considerable weight gain while running, a long racing time, and body-mass-index extremes were associated with hyponatremia, whereas female sex, composition of fluids ingested, and use of nonsteroidal antiinflammatory drugs were not.

Effect of recent antipyretic use on measured fever in the pediatric emergency department.

OBJECTIVES: To determine the prevalence of recent antipyretic use among febrile infants at a pediatric emergency department (ED) and to test the hypothesis that recent antipyretic use is associated with lower measured temperatures in the ED. METHODS: We prospectively enrolled infants younger than 366 days at a pediatric ED. Eligible subjects had a history of fever prior to arrival at the ED or had a measured temperature of 38 degrees C or higher at the ED. Research assistants collected detailed information about recent use of antipyretic drugs. Peak measured temperature prior to arrival at the ED (temperature maximum [Tmax]), measured temperature at the ED, defervescence from Tmax to measured ED temperature, and rates of diagnostic testing were compared between subjects who had or had not been treated with antipyretic medication within the past 6 hours. RESULTS: We enrolled 474 infants. Infants treated with an antipyretic medication (n = 187) had a significantly higher Tmax and a significantly higher measured ED temperature than untreated subjects (n = 287) (P<.001). Treated and untreated subjects did not differ in the amount of defervescence from Tmax to measured ED temperature (P = .41) unless treated subjects included only those who reportedly received therapeutic doses of antipyretic medication within 1 to 5 hours prior to arrival at the ED (P = .02). CONCLUSIONS: Although many febrile infants seen in the pediatric ED have recently received antipyretics, only a few have received a therapeutic dose between 1 and 5 hours prior to arrival. Among febrile infants seen in the ED, recent antipyretic use is associated both with a higher reported Tmax and with higher measured temperatures at the ED. Patients treated with a therapeutic antipyretic dose 1 to 5 hours prior to arrival experience more defervescence from their Tmax than untreated subjects.

When body temperature changes, does rectal temperature lag?

By using temporal artery and rectal thermometers, we followed temperatures in 45 febrile (>38.5 degrees C) infants given an antipyretic drug. Sixty and 90 minutes after drug administration, temporal artery temperatures had decreased significantly more than rectal temperatures. When body arterial temperature changes rapidly, changes in rectal temperature may lag.

How much tachycardia in infants can be attributed to fever?

STUDY OBJECTIVES: We evaluate the hypothesis that pulse rate increases linearly with increased body temperature in infants and determine how much tachycardia in infants can be explained by a 1 degrees C (1.8 degrees F) increase in body temperature. METHODS: Infants younger than 1 year and presenting to a pediatric emergency department were prospectively enrolled. Rectal temperature and pulse rate were measured. Research personnel rated behavioral state as sleeping, awake and quiet, fussy, or crying. Patients were excluded if they were fussy or crying or if they had any medical condition expected to cause tachycardia. The remaining patients were divided into 6 age-based groups. Linear regression analysis of pulse rate and temperature was performed for each group. RESULTS: Four hundred ninety patients were enrolled. Pulse rate increased linearly with temperature in all age groups older than 2 months (adjusted r2=0.102 to 0.376) but not in infants younger than 2 months (adjusted r2=0.004). In infants aged 2 months or older, a multivariate linear regression model adjusted for age showed that pulse rate increased an average of 9.6 beats/min (95% confidence interval 7.7 to 11.5) per 1 degrees C (1.8 degrees F) increase in temperature (adjusted r2=0.225). At any given temperature, the prediction interval for an individual's pulse rate had a span of approximately 64 beats/min. CONCLUSION: In infants 2 to 12 months of age, pulse rate increases linearly with body temperature, with a mean increase of 9.6 beats/min for each 1 degrees C (1.8 degrees F) increase in body temperature. Pulse rates of individual infants vary greatly, however, with a broad range of pulse rates observed at any given temperature.

Can the initial history predict whether a child with a head injury has been abused?

OBJECTIVE: Previous studies of child abuse have used the presenting history as part of the case definition of abuse. Thus, data from these studies cannot be used to determine the diagnostic utility of historical features for identifying cases of abuse. The objective of this study was to determine the diagnostic utility of certain historical features for identifying cases of abusive head trauma. METHODS: We retrospectively studied all children, aged 0 to 3 years, who had acute traumatic intracranial injury and were admitted to a tertiary care pediatric hospital from 1993 to 2000. Cases were categorized as either "definite abuse" or "not definite abuse" on the basis of radiologic, ophthalmologic, and physical examination findings, without regard to the presenting history. RESULTS: Forty-nine (30%) of 163 children met the criteria for definite abuse. Having no history of trauma had a high specificity (0.97) and positive predictive value (PPV; 0.92) for abuse. Among the subgroup of patients with persistent neurologic abnormality at hospital discharge (n = 34), having a history of no or low-impact trauma had a specificity of 1.0 and a PPV of 1.0 for definite abuse. Injuries were blamed on home resuscitative efforts in 12% of definite abuse cases and 0% of not definite abuse cases. The initial history of trauma was changed in 9% of definite abuse cases, as compared with 0% of not definite abuse cases. CONCLUSION: Among young children with a head injury, certain historical features have high specificity and PPV for diagnosing child abuse.

Computerized reminders to physicians in the emergency department: a web-based system to report late-arriving abnormal laboratory results.

Inadequate follow-up for abnormal laboratory results is a frequent cause of medical errors, especially for those that arrive after the patient is discharged in an Emergency Department (ED) setting. We have developed and implemented a computerized reminder system called the Automated Late-Arriving Results Monitoring System (ALARMS) for the Emergency Department at Children's Hospital, Boston. ALARMS scans the hospital's laboratory and ED registration databases to generate an electronic daily log of all late-arriving abnormal results for ED patients, which can be obtained by authorized physicians through a web-based user interface inside the hospital's intranet. We believe, by using this automated data-driven rule-based reminder system, we can minimize the risk of errors resulting from late-arriving laboratory data without requiring substantial additional efforts from clinicians.