Screening and Serial Neutrophil Counts Do Not Contribute to the Recognition or Diagnosis of Late-Onset Neonatal Sepsis

Sepsis Huddles in the Neonatal Intensive Care Unit: A Retrospective Cohort Study of Late-onset Infection Recognition and Severity Assessment

OBJECTIVE

To analyze relationships between provider-documented signs prompting sepsis evaluations, assessments of illness severity, and late-onset infection (LOI).

STUDY DESIGN

Retrospective cohort study of all infants receiving a sepsis huddle in conjunction with a LOI evaluation. Participants were ≥3 days old and admitted to a level IV neonatal intensive care unit (NICU) from September 2018 through May 2021. Data were extracted from standardized sepsis huddle notes in the electronic health record, including clinical signs prompting LOI evaluations, illness severity assessments (from least to most severe: green, yellow, and red), and management plans. To analyze relationships of sepsis huddle characteristics with the detection of culture-confirmed LOI (bacteremia, urinary tract infection, or meningitis), we utilized diagnostic test statistics, area under the receiver-operator characteristic analyses, and multivariable logistic regression.

RESULTS

We identified 1209 eligible sepsis huddles among 604 infants. There were 111 culture-confirmed LOI episodes (9% of all huddles). Twelve clinical signs of infection poorly distinguished infants with and without LOI, with sensitivity for each ranging from 2% to 36% and area under the receiver-operator characteristic ranging 0.49-0.53. Multivariable logistic regression identified increasing odds of infection with higher perceived illness severity at the time of sepsis huddle, adjusted for gestational age and receipt of intensive care supports.

CONCLUSIONS

Clinical signs prompting sepsis huddles were nonspecific and not predictive of concurrent LOI. Higher perceived illness severity was associated with presence of infection, despite some misclassification based on objective criteria. In level IV NICUs, antimicrobial stewardship through development of criteria for antibiotic noninitiation may be challenging, as presenting signs of LOI are similar among infants with and without confirmed infection.

Quality Improvement Through Nurse-initiated Kaiser Sepsis Calculator at a County Hospital

BACKGROUND AND OBJECTIVES

Suspected early onset sepsis drives most antibiotic use in the newborn nursery. The Kaiser Sepsis Calculator (KSC) is a validated tool that safely decreases laboratory evaluation and antibiotic administration in infants aged ≥34 weeks. Our quality improvement aim was a nurse-initiated, KSC-based program to decrease blood cultures (BCx) and complete blood counts (CBC) by 10% from March 2021 to October 2021 among chorioamnionitis-exposed infants born ≥35 weeks' gestation. A secondary aim was to decrease antibiotic administration by 10%.

METHODS

The KSC was implemented for infants at University Health, a county hospital affiliate of the University of Texas Health Science Center San Antonio, with a level I nursery and level IV NICU. The multidisciplinary project included pediatric hospitalists, neonatologists, family practitioners, maternal-fetal medicine physicians, fellows, residents, and nurses. All infants born 6 months before (August 2020-January 2021) and 7 months after protocol implementation (March 2021-September 2021) were analyzed.

RESULTS

A total of 53 chorioamnionitis-exposed infants were included from the preintervention period and 51 from the postintervention period. CBC utilization decreased from 96% to 27%, BCx utilization decreased from 98% to 37%, and antibiotic utilization fell from 25% to 16%. In no cases were antibiotics prescribed against the KSC, and to our knowledge, no early onset sepsis diagnoses or infection-related hospital readmissions were missed.

CONCLUSIONS

The multidisciplinary implementation of the KSC led to a reduction in testing, exceeding our initial goal. A nurse-initiated protocol reduced BCx, CBC, and antibiotic utilization among chorioamnionitis-exposed infants.

Platelets and Immature Neutrophils in Preterm Infants with Feeding Intolerance

OBJECTIVE

Feeding intolerance (FI) is a common presentation of necrotizing enterocolitis (NEC) and sepsis. NEC and sepsis are associated with hematological changes, but these changes alone are not reliable biomarkers for early diagnosis. This study examined whether the combination of hematological indices and FI can be used as an early diagnostic tool for NEC or sepsis.

STUDY DESIGN

This retrospective cohort study included infants born at <1,500 g or <30 weeks who had symptoms of FI. The exclusion criteria were congenital or chromosomal disorders, thrombocytopenia or platelet transfusion before the onset of FI, and history of bowel resection. We compared the hematological indices from infants with pathologic FI (due to NEC or sepsis) to infants with benign FI.

RESULTS

During the study period, 211 infants developed FI; 185 met the inclusion criteria. Infants with pathologic FI (n = 90, 37 cases with NEC and 53 with sepsis) had lower birth gestational age and weight compared with 95 infants with benign FI (n = 95). Pathologic FI was associated with lower platelet count (median 152 × 10³/μL vs. 285 × 10³/μL, p < 0.001) and higher immature-to-total neutrophil (I/T) ratio (median 0.23 vs. 0.04, p < 0.001) at the onset of FI. Pathologic FI was also associated with a decrease in baseline platelets compared with an increase in benign FI. For diagnosis of pathologic FI, a decrease ≥10% in platelets from baseline had a sensitivity and specificity of 0.64 and 0.73, respectively, I/T ratio ≥0.1 had a sensitivity and specificity of 0.71 and 0.78, respectively, and the combination of both parameters had a sensitivity and specificity of 0.50 and 0.97, respectively.

CONCLUSION

FI caused by NEC or sepsis was associated with a decrease in platelets from baseline, and a lower platelet level and higher I/T ratio at the onset of FI. These findings can help clinicians in the management of preterm infants with FI.

KEY POINTS

· FI is a common presentation of NEC and sepsis in preterm infants.. · FI due to NEC or sepsis is associated with changes in platelets and I/T ratio.. · These changes could be useful as early markers for diagnosis..

Antibiotic Discontinuation 24 h After Neonatal Late-Onset Sepsis Work-Up-A Validated Decision Tree Model

Objectives: Neonatal late-onset sepsis work-up is a frequent occurrence in every neonatal department. Blood cultures are the diagnostic gold standard, however, a negative culture prior to 48-72 h is often considered insufficient to exclude sepsis. We aimed to develop a decision tree which would enable exclusion of late-onset sepsis within 24 h using clinical and laboratory variables. Study Design: Infants evaluated for late-onset sepsis during the years 2016-2019, without major malformations, in a tertiary neonatal center were eligible for inclusion. Blood cultures and clinical and laboratory data were extracted at 0 and 24 h after sepsis work-up. Infants with bacteriologically confirmed late-onset sepsis were compared to matched control infants. Univariate logistic regression identified potential risk factors. A decision tree based on Chi-square automatic interaction detection methodology was developed and validated. Results: The study cohort was divided to a development cohort (105 patients) and a validation cohort (60 patients). At 24 h after initial evaluation, the best variables to identify sepsis were C-reactive protein > 0.75 mg/dl, neutrophil-to-lymphocyte ratio > 1.5 and sick-appearance at 24 h. Use of these 3 variables together with blood culture status at 24 h, enabled identification of all infants that eventually developed sepsis through the decision tree model. Our decision tree has an area under the receiver operating characteristic curve of 0.94 (95% CI: 0.90-0.98). Conclusions: In non-sick appearing infants with a negative blood culture at 24 h and normal laboratory values, sepsis is highly unlikely and discontinuing antibiotics after 24 h is a viable option.

Can Procalcitonin Improve Antibiotic Stewardship for Late-Onset Sepsis Evaluations in Neonates?

BACKGROUND

Procalcitonin (PCT) use is not widespread in the neonatal population during late-onset sepsis evaluations. Minimal data exist on appropriate PCT cutoff levels to treat with antibiotics for neonatal sepsis. New guidelines were implemented in select central Texas neonatal intensive care units for late-onset sepsis (infants older than 72 hours) with recommended PCT cutoff levels for antibiotic administration.

PURPOSE

To evaluate antibiotic usage in a local neonatal population following late-onset sepsis workups pre-/postimplementation of a PCT guideline.

METHODS

A retrospective pre-/post-quality improvement project using chart review data was performed over 11 months in 2018. Inclusion criteria were infants older than 72 hours of life having a late-onset sepsis workup. The outcome measure is appropriate antibiotic administration, based on laboratory test results or cultures, for infants pre-/post-PCT guidelines.

RESULTS

The χ test indicated that the proportion of infants receiving appropriate antibiotics pre-/postinitiation of PCT guidelines did not significantly differ. There is, however, clinical significance with an improvement in the proportion of appropriate antibiotic administration and a decrease in variability.

IMPLICATIONS FOR PRACTICE

Using PCT may help the practitioner identify sepsis earlier and more effectively, thereby reducing morbidity and mortality among neonates while improving antibiotic stewardship.

IMPLICATIONS FOR RESEARCH

The small sample size in this study and the limited number of neonatal intensive care units limit any inferences. Future research should evaluate the use of PCT in a larger sample across multiple settings.

Can we improve early identification of neonatal late-onset sepsis? A validated prediction model

OBJECTIVE

No single test can accurately identify neonatal late-onset sepsis (LOS). Our aim was to use clinical evaluation with laboratory tests to rapidly assess sepsis risk.

STUDY DESIGN

A retrospective case-control study was performed in a tertiary Neonatal Center during the years 2016-2019. Infants with bacteriologically confirmed LOS were compared with control infants. A clinical health evaluation score was assigned to each infant. A prediction model was developed and validated by multivariable analysis.

RESULTS

The study included 145 infants, 48 with sepsis, and 97 controls. LOS was independently associated with: sick appearance (OR: 5.7, 95% CI: 1.1-29.1), C-reactive protein > 0.75 (OR: 5.4, 95% CI: 1.1-26.3), and neutrophil-to-lymphocyte ratio > 1.5 (OR: 6.7, 95% CI: 1.2-38.5). Our model had an area under the receiver operating characteristic curve of 0.92 (95% CI: 0.86-0.97).

CONCLUSIONS

Clinical evaluation with neutrophil-to-lymphocyte ratio and C-reactive protein can rapidly identify LOS enabling decreased health costs and antibiotic use.

Automated Versus Manual Band Counts for the Diagnosis of Invasive Bacterial Infections in Infants Who Are Febrile

We conducted a secondary analysis of a prospective study of infants ≤60 days of age who were febrile to assess the diagnostic accuracy of automated vs manual immature neutrophils for invasive bacterial infections. Although manual counts were superior compared with automated counts, bands had suboptimal accuracy overall and had significant variability in test characteristics based on methodology.