Management of neonates at risk of early onset sepsis: a probability-based approach and recent literature appraisal : Update of the Swiss national guideline of the Swiss Society of Neonatology and the Pediatric Infectious Disease Group Switzerland

In Switzerland and other high-income countries, one out of 3000 to 5000 term and late preterm neonates develops early onset sepsis (EOS) associated with a mortality of around 3%, while incidence and mortality of EOS in very preterm infants are substantially higher. Exposure to antibiotics for suspected EOS is disproportionally high compared to the incidence of EOS with consequences for future health and antimicrobial resistance (AMR). A safe reduction of unnecessary antibiotic treatment has to be a major goal of new management strategies and guidelines. Antibiotics should be administered immediately in situations with clinical signs of septic shock. Group B streptococcus (GBS) and Escherichia coli (E. coli) are the leading pathogens of EOS. Amoxicillin combined with an aminoglycoside remains the first choice for empirical treatment. Serial physical examinations are recommended for all neonates with risk factors for EOS. Neonates without any clinical signs suggestive of EOS should not be treated with antibiotics. In Switzerland, we do not recommend the use of the EOS calculator, a risk stratification tool, due to its unclear impact in a population with an observed antibiotic exposure below 3%. Not all neonates with respiratory distress should be empirically treated with antibiotics. Isolated tachypnea or respiratory distress starting immediately after delivery by elective caesarean section or a clearly assessed alternative explanation than EOS for clinical signs may point towards a low probability of sepsis. On the other hand, unexplained prematurity with risk factors has an inherent higher risk of EOS. Before the start of antibiotic therapy, blood cultures should be drawn with a minimum volume of 1 ml in a single aerobic blood culture bottle. This standard procedure allows antibiotics to be stopped after 24 to 36 h if no pathogen is detected in blood cultures. Current data do not support the use of PCR-based pathogen detection in blood as a standard method. Lumbar puncture is recommended in blood culture-proven EOS, critical illness, or in the presence of neurological symptoms such as seizures or altered consciousness. The accuracy of a single biomarker measurement to distinguish inflammation from infection is low in neonates. Therefore, biomarker guidance is not a standard part of decision-making regarding the start or stop of antibiotic therapy but may be used as part of an algorithm and after appropriate education of health care teams. Every newborn started on antibiotics should be assessed for organ dysfunction with prompt initiation of respiratory and hemodynamic support if needed. An elevated lactate may be a sign of poor perfusion and requires a comprehensive assessment of the clinical condition. Interventions to restore perfusion include fluid boli with crystalloids and catecholamines. Neonates in critical condition should be cared for in a specialized unit. In situations with a low probability of EOS, antibiotics should be stopped as early as possible within the first 24 h after the start of therapy. In cases with microbiologically proven EOS, reassessment and streamlining of antibiotic therapy in neonates is an important step to minimize AMR.

CONCLUSION

 This guideline, developed through a critical review of the literature, facilitates a probability-based approach to the management of neonates at risk of early onset sepsis.

WHAT IS KNOWN

• Neonatal exposure to antibiotics is disproportionally high compared with the incidence of early onset sepsis with implications for future health and antimicrobial resistance.

WHAT IS NEW

• A probability-based approach may facilitate a more balanced management of neonatal sepsis and antibiotic stewardship.

Clinical evaluation of cell-direct polymerase chain reaction-based nucleic acid lateral flow immunoassay for rapid detection of bacterial pathogens in clinically suspected sepsis: A multi-center study in Japan

Blood culture, a method for identifying causative agents of bacterial sepsis, requires several days. The combination of cell-direct polymerase chain reaction and nucleic acid lateral flow immunoassay (cdPCR-NALFIA) is a simple and sensitive detection method for identifying pathogenic bacteria. Furthermore, this assay, when applied directly to blood samples yields results within 4.5 h, without requiring culture. This study was performed at five hospitals in Japan between 2013 and 2016. Blood samples from 73 patients with clinically suspected sepsis yielded 18 positive blood cultures, and the isolated bacterial species were detectable using cdPCR-NALFIA in nine samples. Thirteen samples were positive on cdPCR-NALFIA. In total, 17 samples confirmed to have bacterial species were detectable using cdPCR-NALFIA and/or blood culture with a true positive rate of 76.5% and 64.7%, respectively. The combination of blood culture and cdPCR-NALFIA could improve the rate of detection of bacterial sepsis.

Effects of Blood Culture Aerobic/Anaerobic Bottle Collection Patterns from Both Sides of the Body on Positive Blood Culture Rate and Time-to-Positivity

Background

Although the principles for blood cultures (BCs) guidelines provide a recommendation for collection patterns, the complexity of clinical practice occasionally prompts clinicians to adopt non-standard collection patterns. Here, we investigate the influences of different BC collection patterns on detection of pathogens.

Methods

The BC collection patterns of 96 hospitals were surveyed online. And a retrospective study of BC data from a tertiary hospital was conducted.

Results

The results showed that 53.1% of hospitals adopted the recommended patterns. Among the 1439 episodes of true-positive BCs, 67.4% were found in both the left- and right-sided bottles; 58.2% were found in both aerobic and anaerobic bottles.

Conclusion

The present study suggested that the rate of standard collection patterns of blood culture was low and the non-standard collection patterns were associated with decreased detection of pathogens. Simultaneous collection of blood on the left and right sides was recommended as an effective pattern of BC collection.

Neonatal blood culture inoculant volume: feasibility and challenges

BACKGROUND

Clinicians often express concerns about poor sensitivity of blood cultures in neonates resulting from inadequate inoculant volumes. Our objective was to determine the inoculant volume sent for neonatal sepsis evaluations and identify areas of improvement.

METHODS

Single-center prospective observational study of infants undergoing sepsis evaluation. Blood volume was determined by clinician documentation over 21 months, and additionally by weighing culture bottles during 12 months. Adequate volume was defined as ≥1 mL total inoculant per evaluation. For first-time evaluations, local guidelines recommend sending an aerobic-anaerobic pair with 1 mL inoculant in each.

RESULTS

There were 987 evaluations in 788 infants. Clinicians reported ≥1 mL total inoculant in 96.9% evaluations. Among 544 evaluations where bottles were weighed, 93.4% had ≥1 mL total inoculant. Very low birth weight infants undergoing evaluations >7 days after birth had the highest proportion of inadequate inoculants (14.4%). Only 3/544 evaluations and 26/1011 bottles had total inoculant <0.5 mL. Ninety evaluations had <1 mL in both aerobic and anaerobic bottles despite a total inoculant volume that allowed inoculation of ≥1 mL in one of the bottles.

CONCLUSIONS

Obtaining recommended inoculant volumes is feasible in majority of neonates. Measuring inoculant volumes can focus improvement efforts and improve test reliability.

IMPACT

Clinicians express concern about the unreliability of neonatal blood cultures because of inadequate inoculant volume. We investigated over 900 evaluations and found >90% of evaluations have ≥1 mL inoculant. Monitoring adequacy of blood culture technique can identify areas of improvement and may allay concerns about blood culture reliability. Current recommendations for adequate inoculant volume for blood cultures are met in a majority of neonates. Areas of improvement include preterm late-onset sepsis evaluations and distribution techniques during inoculation.