Does leucocytosis identify bacterial infections in febrile neonates presenting to the emergency department?

Abstract

Objective: This study was undertaken to evaluate the discriminatory power of the peripheral white blood cell (WBC) count to identify bacterial infections in a cohort of febrile neonates ((28 days of age) presenting to an emergency department. Methods: Retrospective medical record review using descriptive statistics and a receiver operating characteristic (ROC) curve. Neonates who presented to a tertiary care paediatric emergency department between 1 January 1999 and 22 August 2002, had a temperature >38˚C, underwent lumbar puncture, and had a WBC count obtained were included. They were divided according to microbiological and radiographic findings into four groups: bacterial infections, viral infections, pneumonia, and negative sepsis evaluations. Results: A total of 69 febrile neonates met the inclusion criteria. The number of neonates in each group was as follows: 8 with bacterial infections, 10 with viral infections, 3 with pneumonias, and 48 with negative sepsis evaluations. There was substantial overlap in WBC counts among the groups. The area under the ROC curve was 0.7231 (95% CI 0.5665 to 0.8797). Conclusion: In a cohort of febrile neonates evaluated in the emergency department, the WBC count had modest discriminatory power in identifying neonates with bacterial infections and demonstrated substantial overlap among groups. The present data suggest against the use of any WBC count threshold to identify bacterial infections in febrile neonates presenting to the emergency department.

Etiology and Causative Pathogens of Febrile Neonates

“…This is higher in infants aged 0-28 days (9-28%) than those 2-3 months old (7.1%) [2][3][4][5][6][7][8][9]15,16]. We found the overall rate of SBI was high (38.4%) and our findings confirmed that SBI was seen more frequent in the neonatal period.…”

“…On the other hand, UTI was found higher and reported that 14-21.3 percent in febrile neonatesthat means UTI affects approximately 1 in 6 febrile neonates [2][3][4][5][6][7][8][9][10][11]18]. In our study, UTI incidence was found similarly the most common etiology of fever in neonatal period.…”

“…The overall accuracy of ANC and ABC was greater than that for WBC [14]. The use of CRP showed higher overall accuracy than WBC, ANC, and procalcitonin in accurately diagnosing infants with and without SBI [9,27]. The combination of procalcitonin with urinalysis was reported as more sensitive for identifying SBI in babies between 2 and 60 days old [28].…”

“…Rochester and Philadelphia protocols can be used for identification of Serious bacterial infections in older infants, but in neonatal period sensitivity of these protocols are low [7]. For this reason, it is reported that C-reactive protein (CRP), absolute neutrophil count and procalcitonin levels can be used in SBI determination in the first month of life [6][7][8][9]. Somestudies reported that the contribution of White blood cells count (WBC) in the identification of SBI is very low; thus,importance should be givenon CRP level over absolute neutrophil count and absolute band counts and WBC [4][5][6][7][8][9][10].…”

Hyperleukocytosis in Newborn: A Diagnosis of Concern

“…The clinical signs of leukemia may be evident at birth with hepatosplenomegaly, petechiae and ecchymosis [7]. Leukemic cell infiltration into the skin (leukemia cutis) is commonly found when the disease appears at birth and has also been noted in still born premature infants with leukaemia [8]. Patients with hyperleukocytosis should be closely monitored for its well-known complications like acute respiratory failure, pulmonary hemorrhage, CNS infarction, hemorrhage, splenic infarction, myocardial ischemia, renal failure due to renal vessel leukostasis [1,5].…”