Development, Evaluation and Implementation of Chief Complaint Groupings to Activate Data Collection: A Multi-Center Study of Clinical Decision Support for Children with Head Trauma.

BACKGROUND: Overuse of cranial computed tomography scans in children with blunt head trauma unnecessarily exposes them to radiation. The Pediatric Emergency Care Applied Research Network (PECARN) blunt head trauma prediction rules identify children who do not require a computed tomography scan. Electronic health record (EHR) based clinical decision support (CDS) may effectively implement these rules but must only be provided for appropriate patients in order to minimize excessive alerts. OBJECTIVES: To develop, implement and evaluate site-specific groupings of chief complaints (CC) that accurately identify children with head trauma, in order to activate data collection in an EHR. METHODS: As part of a 13 site clinical trial comparing cranial computed tomography use before and after implementation of CDS, four PECARN sites centrally developed and locally implemented CC groupings to trigger a clinical trial alert (CTA) to facilitate the completion of an emergency department head trauma data collection template. We tested and chose CC groupings to attain high sensitivity while maintaining at least moderate specificity. RESULTS: Due to variability in CCs available, identical groupings across sites were not possible. We noted substantial variability in the sensitivity and specificity of seemingly similar CC groupings between sites. The implemented CC groupings had sensitivities greater than 90% with specificities between 75-89%. During the trial, formal testing and provider feedback led to tailoring of the CC groupings at some sites. CONCLUSIONS: CC groupings can be successfully developed and implemented across multiple sites to accurately identify patients who should have a CTA triggered to facilitate EHR data collection. However, CC groupings will necessarily vary in order to attain high sensitivity and moderate-to-high specificity. In future trials, the balance between sensitivity and specificity should be considered based on the nature of the clinical condition, including prevalence and morbidity, in addition to the goals of the intervention being considered.

Progressive decrease in N-acetylaspartate/Creatine ratio in a teenager with type 1 diabetes and repeated episodes of ketoacidosis without clinically apparent cerebral edema: Evidence for permanent brain injury.

Recent data suggest that DKA may contribute to cognitive impairment in children with type 1 DM. We measured the NAA/Cr ratio in a teenager during and following 2 separate episodes of DKA without clinically apparent cerebral edema. The NAA/Cr ratio decreased during DKA and improved following recovery. However, the NAA/Cr value was lower after the second episode of DKA (1.76) than after the first (1.97). These findings provide support for the hypothesis that neuronal injury may result from DKA.

Cerebral proton magnetic resonance spectroscopy in children with diabetic ketoacidosis.

BACKGROUND AND PURPOSE: Subclinical cerebral edema occurs in many, if not most, children with diabetic ketoacidosis (DKA) and may be an indicator of subtle brain injury. Brain ratios of N-acetylaspartate (NAA) to creatine (Cr), measured by proton MR spectroscopy, decrease with neuronal injury or dysfunction. We hypothesized that brain NAA/Cr ratios may be decreased in children in DKA, indicating subtle neuronal injury. MATERIALS AND METHODS: Twenty-nine children with DKA underwent cerebral proton MR spectroscopy during DKA treatment (2-12 hours after initiating therapy) and after recovery from the episode (72 hours or more after the initiation of therapy). We measured peak heights of NAA, Cr, and choline (Cho) in 3 locations within the brain: the occipital gray matter, the basal ganglia, and periaqueductal gray matter. These regions were identified in previous studies as areas at greater risk for neurologic injury in DKA-related cerebral edema. We calculated the ratios of NAA/Cr and Cho/Cr and compared these ratios during the acute illness and recovery periods. RESULTS: In the basal ganglia, the ratio of NAA/Cr was significantly lower during DKA treatment compared with that after recovery (1.68 +/- 0.24 versus 1.86 +/- 0.28, P<.005). There was a trend toward lower NAA/Cr ratios during DKA treatment in the periaqueductal gray matter (1.66 +/- 0.38 versus 1.91 +/- 0.50, P=.06) and the occipital gray matter (1.97 +/- 0.28 versus 2.13 +/- 0.18, P=.08). In contrast, there were no significant changes in Cho/Cr ratios in any region. CONCLUSIONS: NAA/Cr ratios are decreased in children during DKA and improve after recovery. This finding suggests that during DKA neuronal function or viability or both are compromised and improve after treatment and recovery.

Coagulation testing in pediatric blunt trauma patients.

OBJECTIVES: To determine the prevalence of abnormal coagulation studies and to identify variables associated with markedly elevated coagulation studies in children with blunt trauma. METHODS: We reviewed the medical records of all patients < 15 years old hospitalized at a Level 1 trauma center for either blunt head or torso trauma over a 4-year period. Data from each patient's emergency department (ED) presentation were abstracted. ED coagulation studies were defined prior to data analysis as elevated if the international normalized ratio (INR) was > or =1.2 or partial thromboplastin time (PTT) was > or =33.0 seconds and markedly elevated if the INR was > or =1.5 or PTT was > or =40 seconds. Variables associated with markedly elevated coagulation studies in a univariate analysis (P < 0.05) were entered into a backward elimination logistic regression analysis to identify variables independently associated with markedly elevated coagulation studies. RESULTS: A total of 1082 patients' records were reviewed, and the 830 (77%) patients with coagulation studies obtained composed the study population. Elevated coagulation studies were detected in 232 (28%) patients, and 49 (6%) of these were found to be markedly elevated. In the multivariate analysis, a GCS < or =13 (odds ratio [OR] 8.7, 95% confidence interval [CI] 4.3, 17.7), low systolic blood pressure (OR 4.0, 95% CI 1.6, 9.9), open/multiple bony fractures (OR 2.9, 95% CI 1.4, 6.2), and major tissue wounds (OR 2.8, 95% CI 1.4, 5.6) were independently associated with markedly elevated coagulation studies. CONCLUSION: Hospitalized pediatric blunt trauma patients frequently have minor elevations in ED coagulation studies. Marked elevations occur infrequently and are independently associated with a GCS < or =13, low systolic blood pressure, open/multiple bony fractures, and major tissue wounds.

Emergency department ultrasonography in the evaluation of hypotensive and normotensive children with blunt abdominal trauma.

PURPOSE: The aim of this study was to evaluate the accuracy of emergency department (ED) ultrasound scan in identifying which children with blunt torso trauma have intraperitoneal fluid associated with intraabdominal injuries (IAI). METHODS: The authors conducted a prospective, observational study of children (< 16 years old) with blunt trauma who presented to a level 1 trauma center over a 29-month period and underwent abdominal ultrasound scan while in the ED. Ultrasound examinations were ordered at the discretion of the trauma surgeons or ED physicians caring for the patients, performed by trained sonographers, and interpreted at the time of the ultrasound. Ultrasound examinations were interpreted solely for the presence or absence of intraperitoneal fluid. Hypotension was defined as > or = 1 standard deviation below the age-adjusted mean. Patients underwent follow-up to identify those with intraperitoneal fluid and IAI. RESULTS: A total of 224 pediatric blunt trauma patients had ultrasound scan performed and were enrolled. Thirty-three patients had IAI with intraperitoneal fluid, and ultrasound scan was positive in 27. The accuracy of abdominal ultrasound for detecting intraperitoneal fluid associated with IAI was sensitivity, 82% (95% confidence interval [CI] 65% to 93%); specificity, 95% (95% CI 91% to 97%); positive predictive value, 73% (95% CI 56% to 86%); and negative predictive value, 97% (95% CI 93% to 99%). In the 13 patients who were hypotensive, ultrasound scan correctly identified intraperitoneal fluid in all 7 patients (sensitivity 100%) with IAI, and hemoperitoneum and was negative in all 6 patients (specificity 100%) who did not have hemoperitoneum. Nine patients had IAI without intraperitoneal fluid, and ultrasound scan result was negative for fluid in all 9. CONCLUSIONS: ED abdominal ultrasound scan used solely for the detection of intraperitoneal fluid in pediatric blunt trauma patients has a modest accuracy. Ultrasonography has the best test performance in those children who are hypotensive and should be obtained early in the ED evaluation of these patients.

Prevalence and importance of pneumothoraces visualized on abdominal computed tomographic scan in children with blunt trauma.

BACKGROUND: Chest radiographs are routinely obtained for the identification of pneumothoraces in trauma patients. Computed tomographic (CT) scanning has a higher sensitivity for the detection of pneumothoraces, but the prevalence and importance of pneumothoraces detectable by CT scan but not by chest radiography in children sustaining blunt trauma is unclear. METHODS: We conducted a prospective observational cohort study of children less than 16 years old with blunt trauma undergoing both abdominal CT scan and chest radiography in the emergency department of a Level I trauma center over a 28-month period. All abdominal CT scans were interpreted by a single faculty radiologist. The chest radiographs of all patients with pneumothoraces detected on CT scan as well as a random sample of chest radiographs from pediatric blunt trauma patients without pneumothoraces on abdominal CT scan (in a ratio of four normals per pneumothorax) were reviewed by a second faculty radiologist. Both radiologists were masked to all clinical data as well as to the objective of the study. RESULTS: Five hundred thirty-eight children underwent both abdominal CT scan and chest radiography in the emergency department. Twenty patients (3.7%; 95% confidence interval [CI], 2.3-5.7%) were found to have pneumothoraces on CT scan. Of these 20 patients, 9 (45%; 95% CI, 23-68%) had pneumothoraces identified on initial chest radiography and 11 patients did not ("unsuspected pneumothoraces"). Twelve pneumothoraces were identified in these 11 patients; 6 were graded as minuscule and 6 as anterior according to a previously established scale. One patient with an unsuspected pneumothorax underwent tube thoracostomy. None of the 10 patients (0%; 95% CI, 0-26%) with unsuspected pneumothoraces who were managed without thoracostomy (including two patients who underwent positive pressure ventilation) had complications from their pneumothoraces. CONCLUSION: Less than half of pediatric blunt trauma patients with pneumothoraces visualized on abdominal CT scan had these pneumothoraces identified on initial chest radiograph. Patients with pneumothoraces identified solely on abdominal CT scan, however, uncommonly require tube thoracostomy.

Meningococcal disease among children who live in a large metropolitan area, 1981-1996.

Neisseria meningitidis is an important cause of serious bacterial infections in children. We undertook a study to identify meningococcal infections of the blood, cerebrospinal fluid, or both of children in a defined geographic area to describe the burden of disease and the spectrum of illness. We reviewed the medical records of all children aged <18 years who had meningococcal infections at the 4 pediatric referral hospitals in Boston, Massachusetts, from 1981 through 1996. We identified 231 patients with meningococcal disease; of these 231 patients, 194 (84%) had overt disease and 37 (16%) had unsuspected disease. Clinical manifestations included meningitis in 150 patients, hypotension in 26, and purpura in 17. Sixteen patients (7%) died. Although meningococcal disease is devastating to a small number of children, we found that the burden of pediatric disease that it caused at the 4 pediatric referral centers in this geographic region was limited; that patients with overt meningococcal disease are most likely to have meningitis; and that individual practitioners are unlikely to encounter a patient with unsuspected meningococcal disease.

Risk factors for cerebral edema in children with diabetic ketoacidosis. The Pediatric Emergency Medicine Collaborative Research Committee of the American Academy of Pediatrics.

BACKGROUND: Cerebral edema is an uncommon but devastating complication of diabetic ketoacidosis in children. Risk factors for this complication have not been clearly defined. METHODS: In this multicenter study, we identified 61 children who had been hospitalized for diabetic ketoacidosis within a 15-year period and in whom cerebral edema had developed. Two additional groups of children with diabetic ketoacidosis but without cerebral edema were also identified: 181 randomly selected children and 174 children matched to those in the cerebral-edema group with respect to age at presentation, onset of diabetes (established vs. newly diagnosed disease), initial serum glucose concentration, and initial venous pH. Using logistic regression we compared the three groups with respect to demographic characteristics and biochemical variables at presentation and compared the matched groups with respect to therapeutic interventions and changes in biochemical values during treatment. RESULTS: A comparison of the children in the cerebral-edema group with those in the random control group showed that cerebral edema was significantly associated with lower initial partial pressures of arterial carbon dioxide (relative risk of cerebral edema for each decrease of 7.8 mm Hg [representing 1 SD], 3.4; 95 percent confidence interval, 1.9 to 6.3; P<0.001) and higher initial serum urea nitrogen concentrations (relative risk of cerebral edema for each increase of 9 mg per deciliter [3.2 mmol per liter] [representing 1 SD], 1.7; 95 percent confidence interval, 1.2 to 2.5; P=0.003). A comparison of the children with cerebral edema with those in the matched control group also showed that cerebral edema was associated with lower partial pressures of arterial carbon dioxide and higher serum urea nitrogen concentrations. Of the therapeutic variables, only treatment with bicarbonate was associated with cerebral edema, after adjustment for other covariates (relative risk, 4.2; 95 percent confidence interval, 1.5 to 12.1; P=0.008). CONCLUSIONS: Children with diabetic ketoacidosis who have low partial pressures of arterial carbon dioxide and high serum urea nitrogen concentrations at presentation and who are treated with bicarbonate are at increased risk for cerebral edema.

Antibiotic treatment of children with unsuspected meningococcal disease.

BACKGROUND: Data from an earlier study suggest that patients with unsuspected meningococcal disease (UMD) cannot be differentiated easily from febrile children with viral syndromes on the basis of physical examinations or peripheral blood counts. Some children with meningococcal disease therefore are treated inadvertently as outpatients. OBJECTIVE: To determine whether antibiotic therapy administered at the outpatient visit prevents complications, permanent sequelae, or death in children with UMD. METHODS: We reviewed the medical records of patients younger than 20 years with invasive meningococcal disease at 7 pediatric referral centers from January 1, 1981, through December 31, 1996. Patients were considered to have UMD if they underwent evaluation and discharge as outpatients and if blood and/or cerebrospinal fluid cultures obtained at evaluation yielded Neisseria meningitidis. We compared the frequency of development of complications (meningitis, sepsis, and pericarditis), permanent sequelae (limb amputation, skin grafting, and persistent neurologic disability) or death between patients who did and did not receive antibiotics at the outpatient visits. RESULTS: Of 58 children with UMD, 19 (33%) received antibiotics and 39 (67%) did not. Complications occurred significantly less frequently in the antibiotic-treated group (7/19 [37%] vs 27/39 [69%]; odds ratio [OR], 0.26; 95% confidence interval [CI], 0.08-0.81; P = .03). There was no significant difference in death or permanent sequelae between groups (0/19 vs 3/39 [8%]; OR, 0; 95% CI, 0-2.61; P=.54). There was insufficient power, however, to exclude the possibility of a clinically meaningful difference between the groups with regard to these latter outcomes. CONCLUSIONS: Antibiotic administration to young patients with UMD at the time of the outpatient visit is associated with a reduction in complications from this disease. Although the routine use of antibiotics in febrile outpatients younger than 20 years cannot be advocated, empirical treatment should be considered in the setting of higher probability of meningococcal disease.

Isolated intraperitoneal fluid on abdominal computed tomography in children with blunt trauma.

OBJECTIVE: To determine the frequency of isolated intraperitoneal fluid (IIF) on abdominal computed tomography (CT) in pediatric blunt trauma patients and the association between IIF and clinically identifiable intra-abdominal injuries (IAIs) in these patients. METHODS: The authors conducted a prospective observational study of consecutive children <16 years old with blunt torso trauma who underwent abdominal CT scanning while in the emergency department (ED). All patients were evaluated by a faculty emergency physician who documented the patient's physical examination. All CTs were interpreted by a single faculty radiologist masked to clinical data. The volume of intraperitoneal fluid was quantified (small, moderate, large) and the presence of organ injury visible on CT was noted. Patients were considered to have IIF if the CT demonstrated intraperitoneal fluid and no solid organ injury. Patients with IIF were followed through their hospitalizations or telephoned in one week if discharged home from the ED. RESULTS: Five hundred twenty-seven children with blunt trauma were enrolled into the study. The mean age (+/-SD) was 7.4 +/- 4.7 years, and the median pediatric trauma score was 10 (range -2 to 12). Eighty-eight patients (17%; 95% CI = 14% to 20%) had intraperitoneal fluid on CT scan and 42 (48%; 95% CI = 37% to 59%) of these patients had IIF. Of the 42 patients with IIF, five patients (all without abdominal tenderness and with a small amount of IIF on CT scan) were discharged to home from the ED and were well at telephone follow-up; the remaining 37 patients were hospitalized. Of the 42 patients with IIF, 7 patients (17%, 95% CI = 7 to 31%) had IAIs subsequently identified (all gastrointestinal injuries) during their evaluations. Six of the seven patients with IIF and subsequently identified IAIs had abdominal tenderness on examination in the ED. The remaining patient had a decreased level of consciousness. CONCLUSIONS: Isolated intraperitoneal fluid occurs in 8% of pediatric blunt trauma patients undergoing abdominal CT, and IAIs are subsequently identified in 17% of these patients. Patients with a small amount of IIF on CT who lack abdominal tenderness and have a normal level of consciousness are at low risk for subsequently identified IAIs.

Predictors of intussusception in young children.

OBJECTIVE: To identify predictors of intussusception in young children. DESIGN: A retrospective cross-sectional study. SETTING AND PATIENTS: A consecutive sample of children younger than 5 years on whom contrast enemas were performed because of suspected intussusception seen at an urban children's hospital from 1990 to 1995. METHODS: We evaluated historical, clinical, and radiographic variables. Variables documented in 75% or more of the medical records and associated with intussusception (P< or =.20) in the univariate analysis were evaluated in a multiple logistic regression analysis. Variables retaining significance (P< or =.05) in the multivariate analysis were considered independent predictors of intussusception. We used bootstrap resampling techniques to validate the multivariate model. RESULTS: Sixty-eight (59%) of the 115 patients had intussusception. Univariate predictors of intussusception included male sex, age younger than 2 years, history of emesis, rectal bleeding, lethargy, abdominal mass, and a highly suggestive abdominal radiograph. In the multivariate analysis, we identified only 4 independent predictors (adjusted odds ratio; 95% confidence interval): a highly suggestive abdominal radiograph (18.3; 4.0-83.1), rectal bleeding (17.3; 2.9-104.0), male sex (6.2; 1.2-32.3), and a history of emesis (13.4; 1.4-126.0). We identified 3 of these 4 variables (all but emesis) as independent predictors in more than 50% of 1000 bootstrap data samples. CONCLUSIONS: Rectal bleeding, a highly suggestive abdominal radiograph, and male sex are variables independently associated with intussusception in a cohort of children suspected of having this diagnosis. Knowledge of these variables may assist in clinical decision making regarding diagnostic and therapeutic interventions.

Predictors of adverse events with intramuscular ketamine sedation in children.

STUDY OBJECTIVE: Ketamine is a safe and effective sedative for emergency department procedures in children. However, the use of ketamine sometimes is associated with airway complications, emesis, and recovery agitation. We wished to identify predictors of these adverse events that clinicians might use to risk-stratify children who are candidates for ketamine sedation. METHODS: We analyzed data from 1,021 ED intramuscular ketamine sedations in children 15 years of age or younger at a university medical center and an affiliated county hospital over a 9-year period. Five potential predictor variables (age, gender, American Society of Anesthesiologists' [ASA] risk classification, quantity of first ketamine dose, and number of ketamine doses administered) were compared between children with and without complications. We used multiple logistic regression analyses to determine the association of these 5 variables with emesis and recovery agitation, and validated these analyses with bootstrap resampling techniques. We compared children with and without airway complications using univariate statistics alone, as there were too few patients with airway complications to support a multivariate analysis. RESULTS: No study variables had significant univariate associations with airway complications (all P values >.40). We found emesis to be associated with increasing age in multivariate analysis (odds ratio [OR] 1.25 per year, bias-corrected 95% confidence interval [CI] 1.17 to 1.34, P<.001). The incidence of emesis was 12. 1% in children aged 5 years or older, and 3.5% in those younger than 5 years (Delta8.6%, 95% CI 4.9% to 12.1%). Recovery agitation was associated with the presence of an underlying medical condition (ie, ASA class > or =2, OR 3.05, bias-corrected 95% CI 1.65 to 7.30, P=.004) and inversely associated with increasing age (OR 0.79 per year, bias-corrected 95% CI 0.69 to 0.89, P<.001). The incidence of recovery agitation was 17.9% in ASA class 1 children and 33.3% in children in ASA class 2 or greater (Delta-15.4%, 95% CI 0.0% to -30. 7%). The incidence of recovery agitation was 12.1% in children aged 5 years or older, and 22.5% in those younger than 5 years (Delta-10. 4%, 95% CI -3.0% to -17.7%). Bootstrap resampling techniques validated the importance of the significant variables identified in the regression analyses. CONCLUSION: No study variable was predictive of ketamine-associated airway complications. Emesis that occurred after ketamine administration was modestly associated with increasing age. Recovery agitation was modestly associated with decreasing age and the presence of an underlying medical condition. The discriminatory power of these variables was low enough as to be unlikely to alter clinical decisions regarding patient selection for ketamine administration. No evidence of a significant ketamine dose relationship was noted for airway complications, emesis, or recovery agitation.

Identification of intra-abdominal injuries in children hospitalized following blunt torso trauma.

OBJECTIVE: To determine the utility of the ED physical examination and laboratory analysis in screening hospitalized pediatric blunt trauma patients for intra-abdominal injuries (IAIs). METHODS: The authors reviewed the records of all patients aged <15 years who sustained blunt traumatic injury and were admitted to a Level 1 trauma center over a four-year period. Patients were considered high-risk for IAI if they had any of the following at ED presentation: decreased level of consciousness (GCS < 15), abdominal pain, tenderness on abdominal examination, or gross hematuria. Patients without any of these findings were considered moderate risk for LAI. The authors compared moderate-risk patients with and without IAIs with regard to physical examination and laboratory findings obtained in the ED. RESULTS: Of 1,040 children with blunt trauma, 559 (54%) were high-risk and 481 (46%) were moderate-risk for IAI. 126 (23%) of the high-risk and 22 (4.6%) of the moderate-risk patients had IAIs. Among moderate-risk patients with and without IAIs, those with IAIs were more likely to have abdominal abrasions (5/22 vs 34/459, p = 0.008), an abnormal chest examination (11/22 vs 86/457, p = 0.01), higher mean serum concentrations of aspartate aminotransferase (AST) (604 U/L vs 77 U/L, p < 0.001) and alanine aminotransferase (ALT) (276 U/L vs 39 U/L, p = 0.002), higher mean white blood cell (WBC) counts (16.3 K/mm3 vs 12.8 K/mm3, p < 0.001), and a higher prevalence of >5 RBCs/hpf on urinalysis (7/22 vs 54/427, p = 0.02). There was no significant difference (p > 0.05) between moderate-risk patients with and without IAIs in initial serum concentrations of amylase, initial hematocrit, drop in hematocrit >5 percentage points in the ED, or initial serum bicarbonate concentrations. CONCLUSION: In children hospitalized for blunt torso trauma who are at moderate risk for IAI, ED findings of abdominal abrasions, an abnormal chest examination, and microscopic hematuria as well as elevated levels of AST and ALT, and elevated WBC count are associated with IAI.

Immature neutrophils in the blood smears of young febrile children.

OBJECTIVE: To determine whether the immature neutrophil (band) count in the peripheral blood smear helps to distinguish young febrile children with bacterial or respiratory viral infections. DESIGN AND SETTING: A prospective cohort study in 3 pediatric emergency departments. PATIENTS: A convenience sample of 100 febrile children aged 2 years or younger with either laboratory-documented bacterial infections (n = 31; 24 with urinary tract infections, 7 with bacteremia) or laboratory-documented respiratory viral infections (n = 69). Each patient received a clinical appearance score using the Yale Observation Scale prior to laboratory evaluation. A complete blood cell count was obtained from all patients and manual differential count of the peripheral blood smear was performed by 1 senior technician masked to clinical information. MAIN OUTCOME MEASURE: Band counts, represented as a percentage of white blood cells in the peripheral blood smear, the absolute band count, and band-neutrophil ratio. Logistic regression analysis was performed to determine whether the band count helps to distinguish bacterial infections from viral infections after adjusting for age, temperature, Yale Observation Scale score, and absolute neutrophil count. RESULTS: Patients with bacterial infections had a higher mean absolute neutrophil count (11.3 vs 5.9 x 10(9)/L; P<.01) than patients with respiratory viral infections. There was no difference, however, in percentage band count (13.5% vs 13.3%; P = .90), absolute band count (2.2 vs 1.9 X 10(9)/L; P= .31), or band-neutrophil ratio (0.24 vs 0.33; P = .08, bacterial vs viral, respectively); the band count did not help to distinguish bacterial and viral infections after adjusting for age, temperature, Yale Observation Scale score, and absolute neutrophil count in the regression analysis. CONCLUSION: The band count in the peripheral blood smear does not routinely help to distinguish bacterial infections from respiratory viral infections in young febrile children.

Clinical and hematologic features do not reliably identify children with unsuspected meningococcal disease.

OBJECTIVE: To determine the frequency of unsuspected meningococcal disease (UMD) in young febrile children with meningococcal infections and evaluate whether clinical and laboratory parameters commonly used in the evaluation of fever can help identify children with UMD. METHODS: We reviewed the records of children with meningococcal disease from 1985 to 1996 at four referral centers. Children who were evaluated as outpatients and then discharged to home, from whom Neisseria meningitidis was isolated from blood or cerebrospinal fluid cultures obtained during these outpatient visits, were considered to have UMD. We compared clinical and laboratory parameters between these children and 6414 febrile outpatients 3 to 36 months old with negative blood cultures enrolled in a separate study of occult bacteremia. RESULTS: We identified 381 children with meningococcal disease, of whom 45 (12%) had UMD. Of the 45 with UMD, 37 (82%) were 3 to 36 months old. Compared with the 6414 culture-negative patients, these 37 patients with UMD were significantly younger (8.9 +/- 5.4 vs 14.2 +/- 8.1 months) and had significantly higher band counts (14.3 +/- 11.1 vs 7.3 +/- 7.5%). There were no significant differences, however, in temperature, white blood cell counts, and absolute neutrophil counts. Multivariate analysis identified young age and the band count as independent predictors of UMD. CONCLUSIONS: Children ultimately diagnosed with meningococcal disease have commonly been evaluated as outpatients and discharged to home before diagnosis. Of the hematologic parameters frequently used in the evaluation of fever, only the band count differs significantly between young febrile children with UMD and those with negative cultures. Because UMD is uncommon in young febrile pediatric outpatients, however, the predictive value of the band count is low. Thus, the complete blood count is not routinely helpful for the diagnosis of UMD.

Occult bacteremia in young febrile children.

The evaluation of nontoxic-appearing, young, febrile children has been a subject of considerable debate. Of young, nontoxic-appearing children aged 3 to 36 months with temperatures of 39 degrees C or more and no clear source, approximately 2% to 3% have occult bacteremia. Of these bacteremias, approximately 90% are caused by S. pneumoniae, 5% by nontyphoidal Salmonella sp., and 1% by N. meningitidis. Most children with occult pneumococcal bacteremia improve spontaneously, but approximately 25% of untreated patients have persistent bacteremia or develop new focal infections, including 3% to 6% who develop meningitis. Occult meningococcal bacteremia, although rare, has frequent complications, including meningitis in approximately 40% and death in approximately 4%. Less is known about the natural history of untreated occult nontyphoidal Salmonella bacteremia. Empiric antibiotic treatment of children with occult bacteremia decreases the rate of complications, including meningitis. Few disagree that febrile, young children at risk for occult bacteremia require a careful clinical evaluation and close follow-up. The benefits of laboratory screening and selective empiric antibiotic treatment of febrile children at risk for occult bacteremia have to be weighed against the costs of screening tests and blood cultures, inconvenience, temporary discomfort to patients, risk for side effects of antibiotics, and the role of antibiotics in the development of bacterial resistance. Although great debate exists concerning the role of empiric antibiotics, a strategy for obtaining blood cultures and empirically administering antibiotics on the basis of an increased ANC, in addition to close clinical follow-up, may be effective in reducing the frequency and severity of uncommon but adverse sequelae. A highly effective S. pneumoniae bacterial conjugate vaccine will soon be available, which will benefit all children, and will alter the ways that clinicians evaluate fully immunized young, febrile children.