Fever in infants and children

Diagnostic markers of serious bacterial infections in febrile infants younger than 90 days old

BACKGROUND

The aim of this study was to assess correlations between demographic, clinical and laboratory characteristics and the risk of serious bacterial infection (SBI) in febrile <90-day-old infants.

METHODS

Medical records of all infants younger than 90 days old hospitalized at Dana-Dwek Children's Hospital (2006-2008) for evaluation of fever were retrospectively reviewed. Data on clinical, laboratory and demographic characteristics were retrieved and evaluated.

RESULTS

Forty-eight of the 401 study infants (12%) had SBI: most of them had urinary tract infection (43 infants; 90% of all SBI), three infants had bacteremia, one had bacterial pneumonia and one had bacterial meningitis. Significant independent clinical predictors for the diagnosis of SBI included duration of fever, absence of rhinitis and the absence of lung and skin manifestations. Significant independent laboratory predictors were absolute neutrophil count (ANC), platelets, blood urea nitrogen and C-reactive protein (CRP) level. On receiver operating characteristic curve analysis, the CRP area under the curve (0.819) was significantly superior to ANC and leukocyte count.

CONCLUSION

Of the clinical and laboratory variables selected for evaluation, qualitative CRP was the strongest independent predictor for diagnosing SBI and a significantly better diagnostic marker than clinical characteristics, ANC and white blood cell count.

Clinical accuracy of a non-contact infrared skin thermometer in paediatric practice

BACKGROUND

Rectal thermometry is considered the most reliable method for measuring the temperature in the paediatric population. Recently, a new non-contact skin infrared thermometer for children was introduced in the market with excellent acceptance by parents.

METHODS

A prospective, analytical, cross-sectional study was designed in order to assess the effectiveness of the infrared non-contact thermometer (Thermofocus) in comparison with two other known methods used to measure body temperature. Children aged 1 to 48 months were included from the emergency room and inpatient unit. All patients selected were assessed with three different thermometers: (1) non-contact infrared thermometer (Thermofocus); (2) temporal artery thermometer (Exergen); and (3) rectal glass mercury thermometer.

RESULTS

Four hundred and thirty-four patients were eligible to complete the study. One hundred and sixty-seven were identified with fever. The mean age of the patients studied was 14.6 ± 10.7 months. Both devices were strongly correlated with the rectal temperature: r = 0.950 for Exergen and r = 0.952 for Thermofocus. The mean difference in temperature between the rectal temperature and the non-contact thermometer was 0.029 ± 0.01 °C (P < 0.001), while the mean difference between the temporal artery thermometer and the rectal temperature was -0.20 ± 0.27 °C (P < 0.001). The sensitivity and specificity for the non-contact thermometer is 97%. The negative predictive value is 99%, which is especially important to rule out fever and avoid unnecessary laboratory work-up.

CONCLUSIONS

The non-contact infrared thermometer is a reliable, comfortable and accurate option for measurement of temperature and is very useful for the screening of fever in the paediatric population. More studies are recommended to support the evidence found in this study and compare its accuracy with more complex devices.

Predictors of cerebrospinal fluid pleocytosis in febrile infants aged 0 to 90 days

BACKGROUND

Young infants with fever routinely undergo laboratory evaluation, and many are treated with empirical antibiotics even when the infant seems well. The requirement of a lumbar puncture (LP) as part of a routine evaluation is debated; however, administration of antibiotics without an LP can cause concerns for partially treated bacterial meningitis and make subsequent evaluation of the cerebrospinal fluid (CSF) confusing. The ability to predict which febrile infants have a CSF pleocytosis would assist in the decision to perform LP in febrile infants.

OBJECTIVE

To develop a model to predict which febrile infants have a CSF pleocytosis.

METHODS

We conducted a retrospective review of febrile children aged 90 days or younger seen in the emergency department. Electronic data sources provided the age of the infant, the triage temperature, and all laboratory values. After univariate analysis, recursive partitioning analysis was performed to develop a decision tree to predict febrile infants at increased risk for CSF pleocytosis, defined as a CSF white blood cell (WBC) count of 25/microL or greater in infants 28 days old or younger and 10/microL or greater in those 29 to 90 days old.

RESULTS

Two thousand three febrile infants were studied; 176 (8.8%; 95% confidence interval [CI], 7.6%-10.1%) had a CSF pleocytosis. Presentation during the summer season increased the risk of pleocytosis from 5.0% during nonsummer months to 17.4% (95% CI, 14.6%-20.6%). During the nonsummer season, 7.3% (95% CI, 5.6%-9.5%) of febrile infants with a temperature of greater than 38.4 degrees C and a WBC count of greater than 6100/microL had a CSF pleocytosis, as opposed to 2.9% (95% CI, 1.9%-4.4%) of those with lower temperature or lower WBC count. The decision tree has an overall sensitivity of 89% (95% CI, 83%-92%) and a negative predictive value of 97% (95% CI, 96%-98%).

CONCLUSIONS

A significant number of well-appearing febrile infants will have a CSF pleocytosis. A simple decision tree based on objective clinical information can help identify those at greatest risk for CSF pleocytosis.

Sepsis workup in febrile infants 0-90 days of age with respiratory syncytial virus infection

OBJECTIVES

To ascertain the incidence, determinants, and outcome of sepsis workup in febrile infants aged 0-90 days with respiratory syncytial virus (RSV) infection.

DESIGN

Retrospective chart review.

RESULTS

191 infants with RSV, 21.5% younger than 28 days, were identified; 101 (52.9%) were febrile and 90 were afebrile. Among the febrile infants, 84.2% had blood cultures, 68.3% had urine cultures, and 58.4% had lumbar punctures. Complete sepsis workup was done in 52.5% of the febrile cohort, including 77.3% of those aged less than 28 days. There were 5 cases of urinary tract infection (UTI) [7.2%, 95% confidence interval (CI) = 2.4-16.1] and 1 case of bacteremia (1.2%, 95% CI = 0.0-6.4) among the tested febrile patients. There was no case (0%, 95% CI = 0.0-6.1) of meningitis. Age, maximum temperature, irritability, apnea, decreased intake, chest x-ray findings, and white blood cell count were not predictive of a positive culture. Only 7.8% of the afebrile patients had complete sepsis workup. Fever [risk ratio (RR) = 5.8, 95% CI = 2.8-12], absence of wheezing (RR = 2.1, 95% CI = 1.3-3.6), and age less than 28 days (RR = 1.6, 95% CI = 1.2-2.2) were independent predictors of complete sepsis workup. Overall, complete sepsis workup was associated with a higher rate of antibiotic use (RR = 10.7, 95% CI = 4.9-23.4), increased hospitalization (RR = 2.1, 95% CI = 1.0-4.7), and prolonged hospital stay (median of 2 days vs. 1 day, P = 0.003) compared with those without complete workup.

CONCLUSION

Considerable variability exists in the sepsis workup of febrile infants with suspected RSV infection at our site. Concomitant UTIs are common in febrile, RSV-infected infants.

[Diagnostic test in emergency departments for bacterial infections in infants younger than 12 months]

OBJECTIVE

To evaluate clinical and analytic numeric data that may help the emergency departments to identify bacterial infections in infants.

PATIENTS AND METHODS

A retrospective study of 430 infants with bacterial growth in cultures (culture from blood, 30; urine, 207; stools, 193, and/or cerebrospinal fluid, n 25) was performed. These patients were compared with a control group (n 430), randomly selected from patients aged less than 12 months with negative cultures who were hospitalized with suspected infection. Neonates and surgical patients were excluded from both groups. Statistical analysis was performed using Student's t-test for independent samples, Levene's test for the study of equality of variances, bivariate correlation and one-factor ANOVA, and receiver-operating characteristic (ROC) curves and odds ratios were calculated when statistically significant (p < 0.05) results were obtained. These analyses were performed using the SPSS 10.0 statistical software package.

RESULTS

Of the infants admitted to the pediatric unit, 11.7 % had at least one positive bacterial culture. Temperature (p 0.005), leucocyte count (p 0.003), percentage of neutrophils (p < 0.0001) and C-reactive protein (p < 0.0001) were significantly higher in infants with positive cultures. In invasive infections significant differences were found in sex (more frequent in males) (p 0.03), heart rate (p < 0.0001) and respiratory rate (p 0.003). In the ROC curves, the best diagnostic yield was obtained for C-reactive protein (0.93 for a cutoff value of 29 mg/l, 86 % specificity and 91 % sensitivity).

CONCLUSION

C-reactive protein is essential for diagnosis of bacterial infection in infants in the emergency department.