Peripheral white blood cell counts and bacterial meningitis: implications regarding diagnostic efficacy in febrile children.

In order to investigate the clinical value of peripheral white blood cell variables for the diagnosis of bacterial meningitis among young, febrile children, we compared total peripheral white counts, total segmented neutrophil counts, total band counts, and the ratio of immature-to-total neutrophils (I:T ratio) among 46 children with bacterial meningitis, 130 children with aseptic meningitis, and 56 febrile children with culture confirmed extrameningeal bacterial infection. Children with bacterial meningitis were comparable to those with aseptic meningitis with respect to median total white blood cell counts and median total segmented neutrophil counts but had a significantly higher median total band count (1760/microliters vs 378/microliters, P = 0.0001) and a significantly higher median I:T ratio (0.40 vs 0.09, P less than 0.001). In contrast, children with bacterial meningitis were comparable to those with an extrameningeal bacterial infection with respect to median total band count but had a significantly lower median total peripheral white count (10,650/microliters vs 15,300/microliters, P = 0.0013), a lower median total segmented neutrophil count (4511/microliters vs 6796/microliters, P = 0.023), and a significantly higher median I:T ratio (0.40 vs 0.15, P less than 0.001). Children with meningitis who were bacteremic at presentation had a significantly lower total white cell count (P = 0.001) and significantly higher I:T ratio (P = 0.005) when compared with children who had an extrameningeal infection and concurrent bacteremia at presentation.(ABSTRACT TRUNCATED AT 250 WORDS)

Acute phase reactants and risk of bacterial meningitis among febrile infants and children.

STUDY OBJECTIVE: To test the hypothesis that quantitation of either C-reactive protein (CRP) or the total peripheral WBC count can improve clinical detection of underlying bacterial meningitis among young febrile children. DESIGN: Cross-sectional survey of selected symptoms of central nervous system infection, signs of meningeal irritation and/or elevated intracranial pressure, levels of CRP in serum, and total peripheral WBC counts among unselected pediatric patients undergoing lumbar punctures for evaluation of acute febrile illnesses. SETTING: Emergency department and acute care "walk-in" clinic of an urban, university-affiliated general hospital. PARTICIPANTS: 160 previously well, acutely febrile infants and children (median age, 6 months). RESULTS: The prevalence of bacterial meningitis was 6%. Sensitivity of symptoms was 1.00 and specificity was 0.17. Sensitivity of signs was 0.70 and specificity was 0.81. Of the acute phase reactants, sensitivity of a CRP level of more than 1.0 mg/dL was 0.80, while that of a total peripheral WBC count of more than 15,000/mm3 was 0.40. The presence of signs and/or a CRP level of more than 1.0 mg/dL correctly identified all children with bacterial meningitis (sensitivity, 1.00). The absence of signs and a CRP level of 1.0 mg/dL or less correctly identified 71 of 150 children without bacterial meningitis (specificity, 0.47). Of 125 children without meningeal signs, the combination of symptoms and a CRP level of more than 1.0 mg/dL correctly identified all three children with bacterial meningitis (sensitivity, 1.00). The absence of these symptoms and/or a CRP level of 1.0 mg/dL or less correctly identified 80 of 122 children without bacterial meningitis (specificity, 0.66). CONCLUSION: Quantitation of CRP but not the total peripheral WBC count can increase the sensitivity of physical examination findings and the specificity of symptoms for the diagnosis of bacterial meningitis. Measurement of CRP in serum is useful as an adjunct to history and physical examination for the detection of acute bacterial meningitis in the acutely febrile child.

A prospective randomized double-blind study to evaluate the effect of dexamethasone in acute laryngotracheitis.

To determine whether a single dose of dexamethasone (0.6 mg/kg) is useful in the treatment of acute laryngotracheitis (croup), 29 hospitalized patients with acute laryngotracheitis were randomly assigned in a double-blind fashion to receive either parenterally administered dexamethasone (n = 16) or a saline placebo (n = 13). Severity of the illness was assessed by a clinical croup score based on retractions, stridor, air entry, cyanosis, and level of consciousness. Twelve hours from the time of injection, the patients receiving the dexamethasone had a statistically significant decline in median croup score from 4.5 to 1.0 (p less than 0.001), whereas the patients receiving the placebo did not. By 24 hours, a decline of two or more points in the total croup score was noted in 85% of the patients in the dexamethasone group compared with 33% of the patients in the placebo group (p = 0.027). During this same period, only 19% of patients receiving dexamethasone required two or more racemic epinephrine treatments in comparison with 62% of patients who received the placebo (p less than 0.05). There was no statistical difference between the two groups in improvement in oxygen saturation, respiratory rates, or duration of hospitalization. We conclude that dexamethasone is beneficial in reducing the overall severity of moderate to severe acute laryngotracheitis during the first 24 hours after injection.

Use of enzyme immunoassay for the rapid diagnosis of Chlamydia trachomatis endocervical infection in female adolescents.

Enzyme immunoassay (EIA) has been proposed as an alternative to tissue culture for the detection of Chlamydia trachomatis in cervical specimens. The diagnostic efficacy of EIA was compared to tissue culture in 113 teenaged females attending an adolescent reproductive health program. Infection was diagnosed by tissue culture in 16% of subjects. Compared with tissue culture, EIA demonstrated a sensitivity of 100%, specificity of 88%, positive predictive value of 62%, and a negative predictive value of 100%. These data indicate that EIA is an acceptable alternative to tissue culture when screening for C. trachomatis endocervical infection in adolescent females.

Diagnostic efficacy of two rapid tests for detection of respiratory syncytial virus antigen.

With the availability of ribavirin therapy for serious respiratory syncytial virus (RSV) infections, rapid diagnostic tests for the detection of RSV antigen are increasingly important. Efficacies of a commercially available enzyme immunoassay (EIA) (Abbott Laboratories, North Chicago, Ill.) and a fluorescent-antibody assay (FA) were evaluated in a study involving 135 specimens from children with respiratory symptoms. A nasal wash specimen was cultured immediately on RSV-sensitive A549 cells; the nasal wash was also used for EIA. FA was performed on a nasopharyngeal swab specimen with bovine anti-RSV and anti-bovine immunoglobulin G antisera (Burroughs Wellcome Co., Research Triangle Park, N.C.). A total of 39 specimens (28%) were tissue culture positive, including 35 EIA-positive and 37 FA-positive samples (sensitivities, 90 and 95%, respectively). All 96 tissue culture-negative specimens were EIA negative (specificity, 100%); 94 of these 96 specimens were FA negative (specificity, 98%). Positive and negative predictive values for the tests were as follows: 100 and 96% for EIA, respectively, and 95 and 98% for FA, respectively. Other viruses, including influenza A virus, adenovirus, enterovirus, and herpes simplex virus, were isolated in nine cases. One adenovirus-positive specimen had a false-positive RSV FA result; all nine specimens were RSV EIA negative. Both tests performed well in our study and provide cost-effective alternatives to tissue culture. The RSV EIA, in particular, uses standard serologic techniques and equipment and does not require expertise in virology. More widespread availability of rapid diagnostic tests for RSV will hopefully result in early and appropriate use of antiviral therapy in patients at risk for serious RSV infections.

Observation, history, and physical examination in diagnosis of serious illnesses in febrile children less than or equal to 24 months.

To determine if observational assessment performed in a systematic manner adds to the efficacy of the traditional history and physical examination in detecting serious illnesses in febrile children, and to determine the sensitivity of the combined evaluation, we studied consecutive patients less than or equal to 24 months of age seen for evaluation of fever at the Primary Care Center-Emergency Room (PCC-ER) of the Yale-New Haven Hospital (n = 143) and a suburban private practice (n = 207). An attending pediatrician performed the observation using the previously reported Acute Illness Observation Scales (AIOS). Subsequently, the history and physical examination were done by an attending pediatrician, and findings were scored as to whether they suggested the presence of a serious illness. Thirty-six patients, 28 in the PCC-ER and eight in the private practice, had a serious illness. The combined AIOS, history, and physical examination had a higher sensitivity and r correlation for serious illness than did the traditional history and physical examination. Three children with serious illnesses, all of whom had no abnormalities on history and physical examination, were identified only by use of AIOS. We conclude that assessment of appearance in a child with fever, when performed in a careful, integrated, stepwise fashion, improves the sensitivity of the history and physical examination in detecting serious illnesses in febrile children.

Predictive value of abnormal physical examination findings in ill-appearing and well-appearing febrile children.

In order to study the occurrence and positive predictive value of history and physical examination findings suggestive of serious illness in ill-appearing and well-appearing febrile children, 103 consecutive children aged less than or equal to 24 months with fever greater than or equal to 38.3 degrees C were evaluated from July 1, 1982 to Nov 24, 1982. Patients were initially classified by an attending physician (A) as to whether they appeared ill (Yale Observation Scale score greater than 10) or well (scale score less than or equal to 10). The history was then taken by two attending physicians (A and B) and a resident; the physical examination was performed by attending physician B and the same resident. As history and physical examination findings were elicited, they were scored as to whether they did or did not suggest a serious illness. Serious illness was defined as the presence of a positive laboratory test. Ill-appearing patients had a significantly greater (P less than .001, Fisher's exact test) occurrence of physical examination findings suggesting serious illness (14 of 22, 64%) than well-appearing children (12 of 81, 15%). The positive predictive values of abnormal physical examination findings for serious illness in ill-appearing (11 of 14, 79%) and well-appearing children (3 of 12, 25%) were significantly different (P = .02 by Fisher's exact test). The trends for abnormal history findings in ill-appearing and well-appearing children were similar to those for abnormal physical examination findings but did not achieve statistical significance. The results, indicating an important interaction between a febrile child's appearance and physical examination findings, are discussed in terms of probability reasoning in clinical decision making.

Sleep apnea and related disorders in infants and children.

Interruption of normal ventilation during sleep may underlie a variety of disorders seen in infants and children and mounting evidence indicates a relationship between these episodes and later development of more serious physical problems. The anatomy and physiology of ventilation during sleep and the diagnosis and treatment of sleep- related disorders is discussed. Preliminary information on the prognosis for patients with these disorders is reviewed.