Lumbar Puncture for All Febrile Infants 29-56 Days Old: A Retrospective Cohort Reassessment Study

Abstract

Objectives To determine the incidence of bacterial meningitis (BM) among all febrile infants 29–56 days old undergoing a lumbar puncture (LP) in the emergency department (ED) of a tertiary care children’s hospital and the number of low-risk FYI with BM, in order to reassess the need for routine LP in these infants. Study design Retrospective cohort study using a quality improvement registry from July 2007-April 2014. Infants included were 29–56 days old with fever and who had an LP in the ED. Low-risk criteria were adapted from the Philadelphia criteria. 4BM was defined as having a bacterial pathogen isolated from the cerebrospinal fluid (CSF). A medical record review of one-third of randomly selected patients in the cohort determined the proportion who met low-risk criteria. Results One of 1188 (0.08%) FYI had BM; this patient did not meet low-risk criteria. An additional 40 (3.4%) had positive CSF cultures; all were contaminants. Sub-analysis of one-third of the study population revealed that 45.6% met low-risk criteria; the most common reasons for failing low-risk classification included abnormal white blood cell count or urinalysis. Conclusions In a cohort of FYI, BM is uncommon and no cases of BM would have been missed had LPs not been performed in those meeting low-risk criteria.

Risk Stratification of Febrile Infants ≤60 Days Old Without Routine Lumbar Puncture

“…22 Table 1 lists the components of the Rochester and modified Philadelphia criteria that classified an infant as low risk. 9,23 For both criteria, the definition of a normal urinalysis was based on currently used urine dipstick and microscopy parameters. 20 Band counts require performance of a manual differential on a complete blood count.…”

“…For the Rochester and modified Philadelphia criteria, sensitivity and specificity were calculated and reported with 95% confidence intervals (CIs). Because both the Rochester and Philadelphia criteria have historically used ≤10 WBCs per high-power field (HPF) or ≤10 WBCs per mm 3 on an enhanced urinalysis 2,9,23 to define a normal urinalysis, analyses were repeated by using this definition. Additionally, because the modified Philadelphia criteria were developed for infants ≤56 days of age, 9 analyses were repeated after limiting the sample to infants in this age range.…”

“…12,13 The Rochester criteria and the modified Philadelphia criteria do not require routine CSF testing to classify febrile infants as being at a low or high risk for serious bacterial infection. 2,9 Data regarding the performance characteristics of the Rochester and modified Philadelphia criteria in a large sample of febrile infants ≤60 days of age with IBI would inform the need for routine CSF testing in this population. Our objective was to evaluate the Rochester and modified Philadelphia criteria for the risk stratification of infants with IBI using a contemporary sample of febrile infants ≤60 days of age evaluated in the ED.…”

Performance of the Modified Boston and Philadelphia Criteria for Invasive Bacterial Infections

“…42,43 Consistent with this observation, our observed GBS rates are similar: 22% to 43% (Boston and Philadelphia derivation studies) versus 27% (our study). 16,17,23,25,26,44 Furthermore, with recent data suggesting that lumbar puncture may be safely avoided in some infants 29 to 60 days old, 45 clinicians may be obtaining CSF only from infants with a higher clinical concern for meningitis, thereby leading to the Boston and Philadelphia criteria being applied to a different patient population from which they were derived. Despite this concern, our observed IBI rates are similar to other recent ED febrile infant cohorts.…”

Fever Without a Source in an Infant Due to Severe Acute Respiratory Syndrome Coronavirus-2

“…A complete blood count revealed leukopenia (3000 cells/µL), lymphopenia (1050 cells/µL), neutropenia (1000 cells/µL), normocytic anemia (hemoglobin 10.6 g/dL, hematocrit 31.4%, mean corpuscular volume 94 fL), and normal platelets (204 × 10 3 cells/µL). Due to the infant's age and presentation of fever without a source in the setting of leukopenia, a full infant sepsis evaluation was initiated [3]. A urinalysis demonstrated trace hemoglobin and protein but was otherwise normal.…”