Timing of Multiorgan Dysfunction among Hospitalized Infants with Fatal Fulminant Sepsis

Framework for Considering Abnormal Heart Rate Characteristics and Other Signs of Sepsis in Very Low Birth Weight Infants

OBJECTIVE

A heart rate characteristics index (HeRO score), incorporating low variability and superimposed decelerations, was developed as a sepsis risk indicator for preterm infants in the neonatal intensive care unit (NICU). A rise in the risk score should prompt consideration of other clinical changes that may be signs of sepsis to decide whether a workup and antibiotics are needed. We aimed to develop a framework to systematically consider signs potentially indicating sepsis in very low birth weight (VLBW) infants.

STUDY DESIGN

We developed easy-recall acronyms for 10 signs of sepsis in VLBW infants. Over 12 months in a level IV NICU, neonatology fellows completed a brief survey after each shift to document changes prompting sepsis workups. We analyzed associations between survey data, hourly heart rate characteristic data, and the diagnosis of the workup, grouped as culture-positive sepsis (CXSEP, positive blood or urine culture), clinical sepsis (CLINSEP, negative cultures treated with antibiotics ≥5 days), or sepsis ruled out (SRO, negative cultures and <3 days antibiotics).

RESULTS

We analyzed 93 sepsis workups in 48 VLBW infants (35 CXSEP, 20 CLINSEP, and 38 SRO). The most frequently cited changes prompting the workups were heart rate patterns and respiratory deterioration, which were common in all three categories. Low blood pressure and poor perfusion were uncommonly cited but were more likely to be associated with CXSEP than the other signs. A rise in the HeRO score ≥1 from 0 to 12 hours before compared with 12to 72 hours prior the blood culture occurred in 31% of workups diagnosed as CXSEP, 16% CLINSEP, and 31% SRO.

CONCLUSION

The HeRO score can alert clinicians to VLBW infants at high or increasing risk of a sepsis-like illness, but heart rate characteristic patterns are highly variable in individual babies. The easy-recall NeoSEP-10 framework can assist clinicians in considering other clinical changes when making decisions about sepsis workups and the duration of antibiotics.

KEY POINTS

· Abnormal heart rate characteristics can indicate sepsis or other pathologies in preterm infants.. · We developed a simple bedside tool to consider clinical signs potentially associated with sepsis.. · Considering vital sign trends together with clinical changes is a key to right-timing antibiotics..

Neonatal sepsis and cardiovascular dysfunction I: mechanisms and pathophysiology

The highest incidence of sepsis across all age groups occurs in neonates leading to substantial mortality and morbidity. Cardiovascular dysfunction frequently complicates neonatal sepsis including biventricular systolic and/or diastolic dysfunction, vasoregulatory failure, and pulmonary arterial hypertension. The haemodynamic response in neonatal sepsis can be hyperdynamic or hypodynamic and the underlying pathophysiological mechanisms are heterogeneous. The diagnosis and definition of both neonatal sepsis and cardiovascular dysfunction complicating neonatal sepsis are challenging and not consensus-based. Future developments in neonatal sepsis management will be facilitated by common definitions and datasets especially in neonatal cardiovascular optimisation. IMPACT: Cardiovascular dysfunction is common in neonatal sepsis but there is no consensus-based definition, making calculating the incidence and designing clinical trials challenging. Neonatal cardiovascular dysfunction is related to the inflammatory response, which can directly target myocyte function and systemic haemodynamics.

Inflammatory biomarkers and physiomarkers of late-onset sepsis and necrotizing enterocolitis in premature infants

Background

Early diagnosis of late-onset sepsis (LOS) and necrotizing enterocolitis (NEC) in very low birth weight (VLBW, <1,500 g) infants is challenging due to non-specific clinical signs. Inflammatory biomarkers increase in response to infection, but non-infectious conditions also cause inflammation. Cardiorespiratory data contain physiological biomarkers, or physiomarkers, of sepsis that may be useful in combination with inflammatory hematologic biomarkers for sepsis diagnosis.

Objectives

To determine whether inflammatory biomarkers measured at the time of LOS or NEC diagnosis differ from times without infection and whether biomarkers correlate with cardiorespiratory sepsis physiomarkers in VLBW infants.

Methods

Remnant plasma sample collection from VLBW infants occurred with blood draws for routine laboratory testing and suspected sepsis. We analyzed 11 inflammatory biomarkers and a pulse oximetry sepsis warning score (POWS). We compared biomarker levels obtained at the time of gram-negative (GN) bacteremia or NEC, gram-positive (GP) bacteremia, negative blood cultures, and no suspected infection.

Results

We analyzed 188 samples in 54 VLBW infants. Several biomarkers were increased at the time of GN LOS or NEC diagnosis compared with all other samples. POWS was higher in patients with LOS and correlated with five biomarkers. IL-6 had 78% specificity at 100% sensitivity to detect GN LOS or NEC and added information to POWS.

Conclusions

Inflammatory plasma biomarkers discriminate sepsis due to GN bacteremia or NEC and correlate with cardiorespiratory physiomarkers.

Prognostic accuracy of Neonatal SOFA score versus SIRS criteria in preterm infants with late-onset sepsis

Neonatal SOFA score was reported as an accurate predictor of mortality while the prognostic accuracy of SIRS criteria is unknown. The aim was to compare neonatal SOFA and SIRS criteria for the prediction of late onset sepsis-related mortality in preterm newborns. Newborns ≤ 32 weeks with late onset sepsis were retrospectively studied. Neonatal SOFA and SIRS criteria were calculated at onset of sepsis (T0), and after 6 ± 1 (T1), 12 ± 3 (T2) and 24 ± 3 h (T3). Outcome was death during antibiotic treatment for late onset sepsis. We studied 112 newborns with gestational age 26.9 ± 2.3 weeks; 11% met the study outcome. Neonatal SOFA was significantly higher in non-survivors vs. survivors at all time intervals; SIRS criteria were significantly higher in non-survivors vs. survivors at T1, T2 and T3. Neonatal SOFA increased over time in non-survivors (p = 0.003). At T0, the area under receiver operating characteristics curve was significantly higher for neonatal SOFA score than SIRS criteria (0.950 vs. 0.569; p = 0.0002), and the best calculated cut-off for T0 neonatal SOFA score was 4. In multivariate analysis T0 and T1 neonatal SOFA were predictors of late onset sepsis-related mortality (p = 0.048 and p < 0.001).  Conclusion: Neonatal SOFA score showed greater discriminatory capacity for mortality than SIRS criteria and might be helpful to plan management for patients at higher risk of death. What is Known: • Neonatal SOFA score may be an accurate prognostic tool. • No prognostic score has been fully standardized for septic newborns in NICU. What is New: • Neonatal SOFA score outperformed SIRS criteria for the prediction of prognosis in preterm infants with late onset sepsis. • Neonatal SOFA score assessed at onset of sepsis and 6 hrs later is a predictor of mortality.

Evaluation of the Neonatal Sequential Organ Failure Assessment and Mortality Risk in Neonates with Early-Onset Infection

BACKGROUND

The discriminative utility of the neonatal sequential organ failure assessment (nSOFA) for early-onset sepsis (EOS) mortality in the neonatal intensive care unit (NICU) is unknown.

OBJECTIVES

The objective of the study was to determine the utility of nSOFA for EOS mortality.

METHODS

Multicenter, retrospective cohort study of NICU patients with EOS between 2012 and 2023. nSOFA scores of survivors and non-survivors were compared, and area under the receiver operating characteristics curve (AUROC) for mortality was calculated.

RESULTS

104 subjects were identified (88 lived, 16 died). AUROC at blood culture collection (T0), 6 h after collection (T6), and the maximum nSOFA at T0 or T6 (T0-6max) were 0.76 (95% CI: 0.62, 0.91), 0.89 (0.80, 0.99), and 0.87 (0.77, 0.97), respectively. Analyses restricted to birthweight (<1.5, <1 kg) or gestational age (<32, <29 week) cutoffs revealed AUROC ranges of 0.86-0.92 for T6 and 0.82-0.84 for T0-6max.

CONCLUSIONS

The nSOFA showed good-to-excellent discrimination of mortality among infants with EOS in the NICU.

Use of an electronic medical record to optimize a neonatal sepsis score for mortality prediction

OBJECTIVE

Late-onset sepsis (LOS) is a significant cause of mortality in preterm infants. The neonatal sequential organ failure assessment (nSOFA) provides an objective assessment of sepsis risk but requires manual calculation. We developed an EMR pipeline to automate nSOFA calculation for more granular analysis of score performance and to identify optimal alerting thresholds.

METHODS

Infants born <33 weeks of gestation with LOS were included. A SQL-based pipeline calculated hourly nSOFA scores 48 h before/after sepsis evaluation. Sensitivity analysis identified the optimal timing and threshold of nSOFA for LOS mortality.

RESULTS

Eighty episodes of LOS were identified (67 survivors, 13 non-survivor). Non-survivors had persistently elevated nSOFA scores, markedly increasing 12 h prior to culture. At sepsis evaluation, the AUC for nSOFA >2 was 0.744 (p = 0.0047); thresholds of >3 and >4 produced lower AUCs.

CONCLUSIONS

nSOFA is persistently elevated for infants with LOS mortality compared to survivors with an optimal alert threshold >2.

Sequential organ failure assessment scores to predict outcomes: from adults to neonates

PURPOSE OF REVIEW

Organ dysfunction severity scores (sequential organ failure assessment or SOFA) are commonly used in the adult and pediatric populations when assessing risk of mortality and adverse outcomes from sepsis. In contrast to sepsis definition in adults and children, clinical and laboratory criteria for defining neonatal sepsis have been inconclusive. More recently, studies have attempted to better understand the clinical progression of neonatal sepsis and associated mortality. This data has guided the development of a neonatal SOFA (nSOFA) score, based on common patterns of organ dysfunction observed in this population.

RECENT FINDINGS

Although SOFA scores in the adult and pediatric populations have their limitations with moderate sensitivities and specificities depending on the clinical setting, the nSOFA score has been validated in predicting sepsis attributable mortality in very low birth weight (VLBW) infants across several patient cohorts. Furthermore, the nSOFA score has been adapted for use in neonatal disease states, other than sepsis, with similar prognostic utility.

SUMMARY

Utilizing an nSOFA scoring system for prediction of sepsis attributable mortality in preterm infants allows for targeted interventions based on risk stratification, as well as better delineation of neonatal sepsis with subsequent improvements in research and patient safety outcomes.

Predictors of Mortality in Early Neonatal Sepsis: A Single-Center Experience

Background and Objectives: Early neonatal sepsis is associated with a significant mortality rate despite modern treatment strategies. Our aim was to identify risk factors contributing to the occurrence of death in newborns with early neonatal sepsis. Materials and Methods: We conducted a retrospective cross-sectional study that included newborns with early sepsis who received care in the intensive and semi-intensive care units at the Institute of Neonatology, Belgrade, Serbia. Newborns with early neonatal sepsis who died comprised the case group, whereas those who survived made up the control group. The diagnostic and therapeutic approach to the septic condition was carried out independently of this study, according to valid hospital protocols and current good practice guidelines. The influence of a large number of variables on the examined dichotomous outcome, as well as the mutual interaction of potential predictor variables, was examined by binary logistic regression. Results: The study included 133 pregnant women and 136 newborns with early neonatal sepsis, of which 51 (37.5%) died, while the remaining 85 newborns (62.5%) survived. Newborns who died had a statistically significantly lower birth weight compared to those who survived (882.8 ± 372.2 g vs. 1660.9 ± 721.1 g, p = 0.000). Additionally, compared to newborns who survived, among the deceased neonates there was a significantly higher proportion of extremely preterm newborns (74.5% vs. 22.4%, p = 0.000). The following risk factors for the occurrence of death in early neonatal sepsis were identified: low birth weight, sepsis caused by gram-negative bacteria, and the use of double-inotropic therapy and erythrocyte transfusion during the first week. Conclusions: Pediatricians should pay special attention to infants with early neonatal sepsis in whom any of the identified risk factors are present in order to prevent a fatal outcome.

Sepsis and Mortality Prediction in Very Low Birth Weight Infants: Analysis of HeRO and nSOFA

OBJECTIVE

Scores to predict sepsis or define sepsis severity could improve care for very low birth weight (VLBW) infants. The heart rate characteristics (HRC) index (HeRO score) was developed as an early warning system for late-onset sepsis (LOS), and also rises before necrotizing enterocolitis (NEC). The neonatal sequential organ failure assessment (nSOFA) was developed to predict sepsis-associated mortality using respiratory, hemodynamic, and hematologic data. The aim of this study was to analyze the HRC index and nSOFA near blood cultures in VLBW infants relative to diagnosis and sepsis-associated mortality.

STUDY DESIGN

Retrospective, single-center study of VLBW infants from 2011 to 2019. We analyzed HRC index and nSOFA around blood cultures diagnosed as LOS/NEC. In a subgroup of the cohort, we analyzed HRC and nSOFA near the first sepsis-like illness (SLI) or sepsis ruled-out (SRO) compared with LOS/NEC. We compared scores by diagnosis and mortality during treatment.

RESULTS

We analyzed 179 LOS/NEC, 93 SLI, and 96 SRO blood culture events. In LOS/NEC, the HRC index increased before the blood culture, while nSOFA increased at the time of culture. Both scores were higher in nonsurvivors compared with survivors and in LOS/NEC compared with SRO. The nSOFA 12 hours after the time of blood culture predicted mortality during treatment better than any other time point analyzed (area under the curve 0.91).

CONCLUSION

The HRC index provides earlier warning of imminent sepsis, whereas nSOFA after blood culture provides better prediction of mortality.

KEY POINTS

· The HRC index and nSOFA provide complementary information on sepsis risk and sepsis-related mortality risk.. · This study adds to existing literature evaluating these risk scores independently by analyzing them together and in cases of not only proven but also suspected infections.. · The impact of combining risk models could be improved outcomes for premature infants..

Dopamine or norepinephrine for sepsis-related hypotension in preterm infants: a retrospective cohort study

The purpose of this study is to compare the clinical effectiveness of dopamine (DA) versus norepinephrine (NE) as first-line therapy for sepsis-related hypotension in preterm infants. This is a retrospective cohort study over 10 years at two tertiary neonatal units. Preterm infants born < 35 weeks post-menstrual age (PMA), who received DA or NE as primary therapy for hypotension during sepsis, defined as culture-positive or culture-negative infections or necrotizing enterocolitis (NEC), were included. Episode-related mortality (< 7 days from treatment), pre-discharge mortality, and major morbidities among survivors were compared between two groups. Analyses were adjusted using the inverse probability of treatment weighting estimated by propensity score (PS). A total of 156 infants were included, 113 received DA and 43 NE. The mean ± SD PMA at birth and at treatment for the DA and NE groups were 25.8 ± 2.3 vs. 25.2 ± 2.0 weeks and 27.7 ± 3.0 vs. 27.1 ± 2.6 weeks, respectively (p > 0.05). Pre-treatment, the NE group had higher mean airway pressure (14 ± 4 vs. 12 ± 4 cmH₂O), heart rate (185 ± 17 vs. 175 ± 17 beats per minute), and median (IQR) fraction of inspired oxygen [0.67 (0.42, 1.0) vs. 0.52 (0.32, 0.82)] (p < 0.05 for all). After PS adjustment, NE was associated with lower episode-related mortality [adjusted odds ratio (95% CI) 0.55 (0.33, 0.92)], pre-discharge mortality [0.60 (0.37, 0.97)], post-illness new diagnosis of significant neurologic injury [0.32 (0.13, 0.82)], and subsequent occurrence of NEC/sepsis among the survivors [0.34, (0.18, 0.65)].

CONCLUSION

NE may be more effective than DA for management of sepsis-related hypotension among preterm infants. These data provide a rationale for prospective evaluation of these commonly used agents.

WHAT IS KNOWN

•Dopamine is the commonest vasoactive agent used to support blood pressure among preterm infants. •For adult patients, norepinephrine is recommended as the preferred therapy over dopamine for septic shock.

WHAT IS NEW

•This is the first study examining the relative clinical effectiveness of dopamine and norepinephrine as first-line pharmacotherapy for sepsis-related hypotension among preterm infants. •Norepinephrine use may be associated with lower mortality and morbidity than dopamine in preterm infants with sepsis.

Neonatal Sequential Organ Failure Assessment as a late-onset sepsis mortality predictor in very low birth weight newborns: a Brazilian cohort study

Death is a frequent occurrence in late-onset neonatal sepsis (LOS). We aimed to evaluate if the Neonatal Sequential Organ Failure Assessment (nSOFA) is associated with mortality due to LOS in very low birth weight (VLBW) infants. This is a single-center Brazilian cohort study including VLBW infants admitted between 2006 and 2020 who were diagnosed with LOS caused by Staphylococcus aureus, Enterococcus sp or Gram-negative bacteria. The primary outcome was mortality associated with sepsis. Two groups of patients-survivors and non-survivors-were compared regarding descriptive maternal and neonatal variables and the nSOFA score, evaluated at nine moments, from 48 hours before the diagnosis of sepsis to 48 hours later (T-48, T-24, T-12, T-6, T0, T+6, T+12, T+24, T+48). Diagnostic accuracy was expressed as the area under the curve (AUC). Among the 1574 VLBW infants hospitalized in the period, 114 episodes of culture-confirmed LOS occurred. There were 21 sepsis-related deaths (18.4%), mostly from Gram-negative bacteria and Enterococcus sp. There were no statistically significant differences between the groups regarding maternal and neonatal variables. Median nSOFA was significantly higher in the non-survivor group at all time points (range 2 to 13 versus 1 to 3). In the logistic regression analysis, each increment of one point in the score significantly increases the risk of death in eight of the nine moments, but no difference was found in T-24. Time T-6 had the best accuracy (88.1%).   Conclusion: The nSOFA score was significantly associated with the risk of death from LOS in VLBW infants. What is Known: • The neonatal sepsis may result in organ dysfunction and death, and it is important to find indicators that could identify this clinical progression. • The nSOFA score was proposed in 2020 to predict mortality from LOS, but since it is recent and still in the research phase, further studies are important to improve it before being widely used in clinical practice. What is New: • We showed a significative association between higher nSOFA scores and mortality. Our results corroborate the validity and the importance of the nSOFA score and highlight its high NPV.

A place for neutrophils in the beneficial pathogen-agnostic effects of the BCG vaccine

The BCG vaccine has long been recognized for reducing the risk to suffer from infectious diseases unrelated to its target disease, tuberculosis. Evidence from human trials demonstrate substantial reductions in all-cause mortality, especially in the first week of life. Observational studies have identified an association between BCG vaccination and reduced risk of respiratory infectious disease and clinical malaria later in childhood. The mechanistic basis for these pathogen-agnostic benefits, also known as beneficial non-specific effects (NSE) of BCG have been attributed to trained immunity, or epigenetic reprogramming of hematopoietic cells that give rise to innate immune cells responding more efficiently to a broad range of pathogens. Furthermore, within trained immunity, the focus so far has been on enhanced monocyte function. However, polymorphonuclear cells, namely neutrophils, are not only major constituents of the hematopoietic compartment but functionally as well as numerically represent a prominent component of the immune system. The beneficial NSEs of the BCG vaccine on newborn sepsis was recently demonstrated to be driven by a BCG-mediated numeric increase of neutrophils (emergency granulopoiesis (EG)). And experimental evidence in animal models suggest that BCG can modulate neutrophil function as well. Together, these findings suggest that neutrophils are crucial to at least the immediate beneficial NSE of the BCG vaccine. Efforts to uncover the full gamut of mechanisms underpinning the broad beneficial effects of BCG should therefore include neutrophils at the forefront.

Development of a Novel Assessment Tool and Code Sepsis Checklist for Neonatal Late-Onset Sepsis

BACKGROUND

Accurate diagnosis and timely management of neonatal late-onset sepsis (nLOS) have been less well-studied than those of early-onset sepsis. We noticed a delay in nLOS detection and management in our neonatal intensive care unit.

PURPOSE

To develop an assessment tool to aid in the recognition and reporting of nLOS and to standardize the management process once sepsis is recognized.

METHODS

The Plan-Do-Study-Act (PDSA) improvement model provided the framework for interventions for our antibiotic stewardship program, including the aims of this project. A literature review was performed to evaluate tools and other literature available to guide the evaluation and management of suspected sepsis. A quality improvement project was initiated to develop tools for the detection and management of nLOS.

RESULTS

An nLOS assessment tool to help identify neonates at risk for nLOS and a Code Sepsis checklist to standardize the process of evaluation and management of nLOS were developed. The guiding principles of this tool development were empowerment of nurses to initiate the assessment process, clarification of team roles, and removal of barriers to appropriate antibiotic administration.

IMPLICATIONS FOR PRACTICE

Useful and practical tools valued by nursing and the multidisciplinary team may facilitate timely identification and treatment of infants with nLOS.

IMPLICATIONS FOR RESEARCH

Future directions include validation of the nLOS assessment tool and the Code Sepsis checklist as well as ensuring the reliability of the tool to improve detection of nLOS and to reduce time to administer antibiotics in cases of nLOS.

Risk Factors for Mortality From Late-Onset Sepsis Among Preterm Very-Low-Birthweight Infants: A Single-Center Cohort Study From Singapore

OBJECTIVE

To determine the risk factors for mortality associated with late onset sepsis (LOS) among preterm very-low-birthweight (VLBW) infants.

STUDY DESIGN

We performed a retrospective cohort study of infants born <32 weeks gestation and <1,500 gm admitted to a Singaporean tertiary-level neonatal intensive care unit. We determined the clinical, microbial, and laboratory risk factors associated with mortality due to culture-positive LOS in this cohort.

RESULTS

A total of 1,740 infants were admitted, of which 169 (9.7%) developed LOS and 27 (16%) died. Compared to survivors, those who died had lower birth gestational age (median 24 vs. 25 weeks, p = 0.02) and earlier LOS occurrence (median 10 vs. 17 days, p = 0.007). There was no difference in the incidence of meningitis (11.1 vs. 16.9%, p = 0.3), NEC (18.5 vs. 14.8%, p = 0.6), or intestinal surgery (18.5 vs. 23.3%, p = 0.6) among infants who died compared to survivors. Gram-negative bacteria accounted for 21/27 (77.8%) LOS-associated deaths and almost all (13/14, 93%) fulminant episodes. The presence of multiorgan failure, as evidenced by the need for mechanical ventilation (100 vs. 79.0%, p = 0.008), elevated lactate (12.4 vs. 2.1 mmol/L, p < 0.001), and inotropic support (92.6 vs. 37.5%, p < 0.001), was significantly associated with mortality. Infants who died had significantly lower white blood cell (WBC) counts (median 4.2 × 109/L vs. 9.9 × 109/L, p = 0.001), lower platelet count (median 40 × 109/L vs. 62 × 109/L, p = 0.01), and higher immature to total neutrophil (I: T) ratio (0.2 vs. 0.1, p = 0.002). Inotrope requirement [AOR 22.4 (95%CI 2.9, 103.7)], WBC <4 × 109/L [AOR 4.7 (1.7, 13.2)], and I: T ratio >0.3 [AOR 3.6 (1.3, 9.7)] were independently associated with LOS mortality.

CONCLUSIONS

In a setting with predominantly Gram-negative bacterial infections, the need for inotropic support, leukopenia, and elevated I: T ratio were significantly associated with LOS mortality among preterm VLBW infants.

Targeting the Toll-like receptor pathway as a therapeutic strategy for neonatal infection

Toll-like receptors (TLRs) are crucial transmembrane receptors that form part of the innate immune response. They play a role in the recognition of various microorganisms and their elimination from the host. TLRs have been proposed as vital immunomodulators in the regulation of multiple neonatal stressors that extend beyond infection such as oxidative stress and pain. The immune system is immature at birth and takes some time to become fully established. As such, babies are especially vulnerable to sepsis at this early stage of life. Findings suggest a gestational age-dependent increase in TLR expression. TLRs engage with accessory and adaptor proteins to facilitate recognition of pathogens and their activation of the receptor. TLRs are generally upregulated during infection and promote the transcription and release of proinflammatory cytokines. Several studies report that TLRs are epigenetically modulated by chromatin changes and promoter methylation upon bacterial infection that have long-term influences on immune responses. TLR activation is reported to modulate cardiorespiratory responses during infection and may play a key role in driving homeostatic instability observed during sepsis. Although complex, TLR signaling and downstream pathways are potential therapeutic targets in the treatment of neonatal diseases. By reviewing the expression and function of key Toll-like receptors, we aim to provide an important framework to understand the functional role of these receptors in response to stress and infection in premature infants.

Multidrug-Resistant Healthcare-Associated Infections in Neonates with Severe Respiratory Failure and the Impacts of Inappropriate Initial Antibiotic Therap

Background: Multidrug-resistant (MDR) pathogens have emerged as an important issue in neonatal intensive care units (NICUs), especially in critically ill neonates with severe respiratory failure. We aimed to investigate neonatal healthcare-associated infections (HAIs) caused by MDR pathogens and the impacts of inappropriate initial antibiotic therapy on the outcomes. Methods: We retrospectively analyzed all cases of HAIs in neonates with severe respiratory failure in a tertiary-level NICU in Taiwan between January 2014 and May 2020. All clinical features, microbiology, therapeutic interventions, and outcomes were compared between the MDR-HAI and non-MDR HAI groups. Multivariate regression analyses were used to investigate independent risk factors for sepsis-attributable mortality. Results: A total of 275 critically ill neonates with severe respiratory failure who had HAIs were enrolled. Ninety-five cases (34.5%) were caused by MDR pathogens, and 141 (51.3%) cases had positive bacterial cultures from multiple sterile sites. In this cohort, the MDR-HAI group was more likely to receive inappropriate initial antibiotic therapy (51.0% versus 4.7%, respectively; p < 0.001) and exhibit delayed control of the infectious focus (52.6% versus 37.8%, respectively; p = 0.021) compared with the non-MDR HAI group. The sepsis-attributable and final in-hospital rates were 21.8% and 37.1%, respectively, and they were comparable between the MDR-HAI and non-MDR HAI groups. Empirically broad-spectrum antibiotics were prescribed in 76.7% of cases, and inappropriate initial antibiotic treatment was not significantly associated with worse outcomes. Independent risk factors for sepsis-attributable mortality in neonates with severe respiratory failure included the presence of septic shock (OR: 3.61; 95% CI: 1.54–8.46; p = 0.003), higher illness severity (OR: 1.33; 95% CI: 1.04–1.72; p = 0.026), and neonates with bronchopulmonary dysplasia (OR: 2.99; 95% CI: 1.47–6.09; p = 0.003). Conclusions: MDR pathogens accounted for 34.5% of all neonatal HAIs in the NICU, but neither MDR pathogens nor inappropriate initial antibiotics were associated with final adverse outcomes. Because the overuse of broad-spectrum antibiotics has emerged as an important issue in critically ill neonates, the implementation of antimicrobial stewardship to promote the appropriate use of antimicrobials is urgently needed.

Ultra-High Packing Density Next Generation Microtube Array Membrane for Absorption Based Applications

Previously, we successfully developed an extracorporeal endotoxin removal device (EERD) that is based on the novel next generation alternating microtube array membrane (MTAM-A) that was superior to the commercial equivalent. In this article, we demonstrated multiple different parameter modifications that led to multiple different types of novel new MTAM structures, which ultimately led to the formation of the MTAM-A. Contrary to the single layered MTAM, the MTAM-A series consisted of a superior packing density fiber connected in a double layered, alternating position which allowed for the greater fiber count to be packed per unit area. The respective MTAM variants were electrospun by utilizing our internally developed tri-axial electrospinning set up to produce the novel microstructures as seen in the respective MTAM variants. A key uniqueness of this study is the ability to produce self-arranged fibers into the respective MTAM variants by utilizing a single spinneret, which has not been demonstrated before. Of the MTAM variants, we observed a change in the microstructure from a single layered MTAM to the MTAM-A series when the ratio of surfactant to shell flow rate approaches 1:1.92. MTAM-A registered the greatest surface area of 2.2 times compared to the traditional single layered MTAM, with the greatest tensile strength at 1.02 ± 0.13 MPa and a maximum elongation of 57.70 ± 9.42%. The MTAM-A was selected for downstream immobilization of polymyxin B (PMB) and assembly into our own internally developed and fabricated dialyzer housing. Subsequently, the entire setup was tested with whole blood spiked with endotoxin; and benchmarked against commercial Toraymyxin fibers of the same size. The results demonstrated that the EERD based on the MTAM-A performed superior to that of the commercial equivalent, registering a rapid reduction of 73.18% of endotoxin (vs. Toraymyxin at 38.78%) at time point 15 min and a final total endotoxin removal of 89.43% (vs. Toraymyxin at 65.03%).

Acute Kidney Injury Associated with Late-Onset Neonatal Sepsis: A Matched Cohort Study

OBJECTIVES

To determine incidence and severity of acute kidney injury (AKI) within 7 days of sepsis evaluation and to assess AKI duration and the association between AKI and 30-day mortality.

STUDY DESIGN

Retrospective, matched cohort study in a single-center level IV neonatal intensive care unit. Eligible infants underwent sepsis evaluations at ≥72 hours of age during calendar years 2013-2018. Exposed infants (cases) were those with culture-proven sepsis and antimicrobial duration ≥5 days. Nonexposed infants (controls) were matched 1:1 to exposed infants based on gestational and corrected gestational age, and had negative sepsis evaluations with antibiotic durations <48 hours. AKI was defined by modified neonatal Kidney Disease Improving Global Outcomes criteria. Statistical analysis included Mann-Whitney and χ² tests, multivariable logistic regression, and Kaplan-Meier time-to-event analysis.

RESULTS

Among 203 episodes of late-onset sepsis, 40 (20%) developed AKI within 7 days after evaluation, and among 193 episodes with negative cultures, 16 (8%) resulted in AKI (P = .001). Episodes of sepsis also led to greater AKI severity, compared with nonseptic episodes (P = .007). The timing of AKI onset and AKI duration did not differ between groups. Sepsis was associated with increased odds of developing AKI (aOR, 3.0; 95% CI, 1.5-6.2; P = .002). AKI was associated with increased 30-day mortality (aOR, 4.5; 95% CI, 1.3-15.6; P = .017).

CONCLUSIONS

Infants with late-onset sepsis had increased odds of AKI and greater AKI severity within 7 days of sepsis evaluation, compared with age-matched infants without sepsis. AKI was independently associated with increased 30-day mortality. Strategies to mitigate AKI in critically ill neonates with sepsis may improve outcomes.

Evaluation of the Neonatal Sequential Organ Failure Assessment and Mortality Risk in Preterm Infants With Late-Onset Infection

IMPORTANCE

Infection in neonates remains a substantial problem. Advances for this population are hindered by the absence of a consensus definition for sepsis. In adults, the Sequential Organ Failure Assessment (SOFA) operationalizes mortality risk with infection and defines sepsis. The generalizability of the neonatal SOFA (nSOFA) for neonatal late-onset infection-related mortality remains unknown.

OBJECTIVE

To determine the generalizability of the nSOFA for neonatal late-onset infection-related mortality across multiple sites.

DESIGN, SETTING, AND PARTICIPANTS

A multicenter retrospective cohort study was conducted at 7 academic neonatal intensive care units between January 1, 2010, and December 31, 2019. Participants included 653 preterm (<33 weeks) very low-birth-weight infants.

EXPOSURES

Late-onset (>72 hours of life) infection including bacteremia, fungemia, or surgical peritonitis.

MAIN OUTCOMES AND MEASURES

The primary outcome was late-onset infection episode mortality. The nSOFA scores from survivors and nonsurvivors with confirmed late-onset infection were compared at 9 time points (T) preceding and following event onset.

RESULTS

In the 653 infants who met inclusion criteria, median gestational age was 25.5 weeks (interquartile range, 24-27 weeks) and median birth weight was 780 g (interquartile range, 638-960 g). A total of 366 infants (56%) were male. Late-onset infection episode mortality occurred in 97 infants (15%). Area under the receiver operating characteristic curves for mortality in the total cohort ranged across study centers from 0.71 to 0.95 (T0 hours), 0.77 to 0.96 (T6 hours), and 0.78 to 0.96 (T12 hours), with utility noted at all centers and in aggregate. Using the maximum nSOFA score at T0 or T6, the area under the receiver operating characteristic curve for mortality was 0.88 (95% CI, 0.84-0.91). Analyses stratified by sex or Gram-stain identification of pathogen class or restricted to infants born at less than 25 weeks' completed gestation did not reduce the association of the nSOFA score with infection-related mortality.

CONCLUSIONS AND RELEVANCE

The nSOFA score was associated with late-onset infection mortality in preterm infants at the time of evaluation both in aggregate and in each center. These findings suggest that the nSOFA may serve as the foundation for a consensus definition of sepsis in this population.

Challenges in developing a consensus definition of neonatal sepsis

Sepsis remains a leading cause of morbidity and mortality in the neonatal population, and at present, there is no unified definition of neonatal sepsis. Existing consensus sepsis definitions within paediatrics are not suited for use in the NICU and do not address sepsis in the premature population. Many neonatal research and surveillance networks have criteria for the definition of sepsis within their publications though these vary greatly and there is typically a heavy emphasis on microbiological culture. The concept of organ dysfunction as a diagnostic criterion for sepsis is rarely considered in neonatal literature, and it remains unclear how to most accurately screen neonates for organ dysfunction. Accurately defining and screening for sepsis is important for clinical management, health service design and future research. The progress made by the Sepsis-3 group provides a roadmap of how definitions and screening criteria may be developed. Similar initiatives in neonatology are likely to be more challenging and would need to account for the unique presentation of sepsis in term and premature neonates. The outputs of similar consensus work within neonatology should be twofold: a validated definition of neonatal sepsis and screening criteria to identify at-risk patients earlier in their clinical course. IMPACT: There is currently no consensus definition of neonatal sepsis and the definitions that are currently in use are varied.A consensus definition of neonatal sepsis would benefit clinicians, patients and researchers.Recent progress in adults with publication of Sepsis-3 provides guidance on how a consensus definition and screening criteria for sepsis could be produced in neonatology.We discuss common themes and potential shortcomings in sepsis definitions within neonatology.We highlight the need for a consensus definition of neonatal sepsis and the challenges that this task poses.

A neonatal sequential organ failure assessment score predicts mortality to late-onset sepsis in preterm very low birth weight infants

BACKGROUND

An operational definition of organ dysfunction applicable to neonates that predicts mortality in the setting of infection is lacking. We determined the utility of an objective, electronic health record (EHR)-automated, neonatal sequential organ failure assessment (nSOFA) score to predict mortality from late-onset sepsis (LOS) in premature, very low birth weight (VLBW) infants.

METHODS

Retrospective, single-center study of bacteremic preterm VLBW newborns admitted between 2012 and 2016. nSOFA scores were derived for patients with LOS at multiple time points surrounding the sepsis evaluation.

RESULTS

nSOFA scores at evaluation and at all points measured after evaluation were different between survivors and non-survivors. Among patients with an nSOFA score of >4, mortality was higher at evaluation (13% vs 67%, p < 0.001), +6 h (15% vs 64%, p = 0.002), and +12 h (7% vs 71%, p < 0.001) as compared to patients with a score of ≤4. Receiver operating characteristics area under the curve was 0.77 at evaluation (95% CI 0.62-0.92; p = 0.001), 0.78 at +6 h (0.66-0.92; p < 0.001), and 0.93 at +12 h (0.86-0.997; p < 0.001).

CONCLUSIONS

The nSOFA scoring system predicted mortality in VLBW infants with LOS and this automated system was integrated into our EHR. Prediction of LOS mortality is a critical step toward improvements in neonatal sepsis outcomes.

Performance of Pediatric Systemic Inflammatory Response Syndrome and Organ Dysfunction Criteria in Late-Onset Sepsis in a Quaternary Neonatal Intensive Care Unit: A Case-Control Study

OBJECTIVES

To evaluate accuracy of systemic inflammatory response syndrome (SIRS) criteria in identifying culture-proven late-onset neonatal sepsis and to assess prevalence of organ dysfunction and its relationship with SIRS criteria.

STUDY DESIGN

This was a retrospective case-control study of patients in the Children's Hospital of Philadelphia level IV neonatal intensive care unit undergoing sepsis evaluations (concurrent blood culture and antibiotics). During calendar years 2016-2017, 77 case and 77 control sepsis evaluations were identified. Cases included infants who had sepsis evaluations with positive blood cultures and antibiotic duration ≥7 days. Controls were matched by gestational and postmenstrual age, and had sepsis evaluations with negative blood cultures and antibiotic duration ≤48 hours. SIRS criteria were determined at time of sepsis evaluation, and organ dysfunction evaluated in the 72 hours following sepsis evaluation. Statistical analysis included descriptive statistics, Mann-Whitney tests, and χ² (Fisher exact) tests.

RESULTS

At time of sepsis evaluation, 42% of cases and 26% of controls met SIRS criteria. Among infants of ≤37 weeks postmenstrual age, SIRS criteria were met in only 17% of sepsis evaluations (4 of 23 in both cases and controls). Test characteristics for SIRS at diagnosis of culture-proven sepsis included sensitivity 42% and specificity 74%. Cases had higher rates of new organ dysfunction within 72 hours (40% vs 21%); however, 58% of cases developing organ dysfunction did not meet SIRS criteria at time of sepsis evaluation. Of 6 deaths (all cases with organ dysfunction), 2 did not meet SIRS criteria at sepsis evaluation.

CONCLUSIONS

SIRS criteria did not accurately identify culture-proven late-onset sepsis, with poorest accuracy in preterm infants. SIRS criteria did not predict later organ dysfunction or mortality.

Surviving Sepsis in a Referral Neonatal Intensive Care Unit: Association between Time to Antibiotic Administration and In-Hospital Outcomes

OBJECTIVE

To determine if time to antibiotic administration is associated with mortality and in-hospital outcomes in a neonatal intensive care unit (NICU) population.

STUDY DESIGN

We conducted a prospective evaluation of infants with suspected sepsis between September 2014 and February 2018; sepsis was defined as clinical concern prompting blood culture collection and antibiotic administration. Time to antibiotic administration was calculated from time of sepsis identification, defined as the order time of either blood culture or an antibiotic, to time of first antibiotic administration. We used linear models with generalized estimating equations to determine the association between time to antibiotic administration and mortality, ventilator-free and inotrope-free days, and NICU length of stay in patients with culture-proven sepsis.

RESULTS

Among 1946 sepsis evaluations, we identified 128 episodes of culture-proven sepsis in 113 infants. Among them, prolonged time to antibiotic administration was associated with significantly increased risk of mortality at 14 days (OR, 1.47; 95% CI, 1.15-1.87) and 30 days (OR, 1.47; 95% CI, 1.11-1.94) as well as fewer inotrope-free days (incidence rate ratio, 0.91; 95% CI, 0.84-0.98). No significant associations with ventilator-free days or NICU length of stay were demonstrated.

CONCLUSIONS

Among infants with sepsis, delayed time to antibiotic administration was an independent risk factor for death and prolonged cardiovascular dysfunction. Further study is needed to define optimal timing of antimicrobial administration in high-risk NICU populations.

Neonatal Sepsis of Early Onset, and Hospital-Acquired and Community-Acquired Late Onset: A Prospective Population-Based Cohort Study

OBJECTIVE

To assess the epidemiology of blood culture-proven early- (EOS) and late-onset neonatal sepsis (LOS).

STUDY DESIGN

All newborn infants admitted to tertiary care neonatal intensive care units in Switzerland and presenting with blood culture-proven sepsis between September 2011 and December 2015 were included in the study. We defined EOS as infection occurring <3 days after birth, and LOS as infection ≥3 days after birth. Infants with LOS were classified as having community-acquired LOS if onset of infection was ≤48 hours after admission, and hospital-acquired LOS, if onset was >48 hours after admission. Incidence was estimated based on the number of livebirths in Switzerland and adjusted for the proportion of admissions at centers participating in the study.

RESULTS

We identified 444 episodes of blood culture-proven sepsis in 429 infants; 20% of cases were EOS, 62% hospital-acquired LOS, and 18% community-acquired LOS. The estimated national incidence of EOS, hospital-acquired LOS, and community-acquired LOS was 0.28 (95% CI 0.23-0.35), 0.86 (0.76-0.97), and 0.28 (0.23-0.34) per 1000 livebirths. Compared with EOS, hospital-acquired LOS occurred in infants of lower gestational age and was more frequently associated with comorbidities. Community-acquired LOS was more common in term infants and in male infants. Mortality was 18%, 12%, and 0% in EOS, hospital-acquired LOS, and community-acquired LOS, and was higher in preterm infants, in infants with septic shock, and in those requiring mechanical ventilation.

CONCLUSIONS

We report a high burden of sepsis in neonates with considerable mortality and morbidity. EOS, hospital-acquired LOS, and community-acquired LOS affect specific patient subgroups and have distinct clinical presentation, pathogens and outcomes.