Clinician observation of physiological trend monitoring to identify late-onset sepsis in preterm infants

Vital sign metrics of VLBW infants in three NICUs: implications for predictive algorithms

BACKGROUND

Continuous heart rate (HR) and oxygenation (SpO₂) metrics can be useful for predicting adverse events in very low birth weight (VLBW) infants. To optimize the utility of these tools, inter-site variability must be taken into account.

METHODS

For VLBW infants at three neonatal intensive care units (NICUs), we analyzed the mean, standard deviation, skewness, kurtosis, and cross-correlation of electrocardiogram HR, pulse oximeter pulse rate, and SpO₂. The number and durations of bradycardia and desaturation events were also measured. Twenty-two metrics were calculated hourly, and mean daily values were compared between sites.

RESULTS

We analyzed data from 1168 VLBW infants from birth through day 42 (35,238 infant-days). HR and SpO₂ metrics were similar at the three NICUs, with mean HR rising by ~10 beats/min over the first 2 weeks and mean SpO₂ remaining stable ~94% over time. The number of bradycardia events was higher at one site, and the duration of desaturations was longer at another site.

CONCLUSIONS

Mean HR and SpO₂ were generally similar among VLBW infants at three NICUs from birth through 6 weeks of age, but bradycardia and desaturation events differed in the first 2 weeks after birth. This highlights the importance of developing predictive analytics tools at multiple sites.

IMPACT

HR and SpO₂ analytics can be useful for predicting adverse events in VLBW infants in the NICU, but inter-site differences must be taken into account in developing predictive algorithms. Although mean HR and SpO₂ patterns were similar in VLBW infants at three NICUs, inter-site differences in the number of bradycardia events and duration of desaturation events were found. Inter-site differences in bradycardia and desaturation events among VLBW infants should be considered in the development of predictive algorithms.

Visual assessment of heart rate variability patterns associated with neonatal infection in preterm infants

Early identification of neonatal sepsis may help reduce morbidity. From Heart Rate Variability (HRV) visually assessed in preterm infants, eight of nine recordings in babies with positive blood cultures had low HRV and six infants without positive cultures had normal HRV. Straightforward HRV display could help identify infection in infants.

Prediction models for neonatal health care-associated sepsis: a meta-analysis

BACKGROUND AND OBJECTIVES

Blood culture is the gold standard to diagnose bloodstream infection but is usually time-consuming. Prediction models aim to facilitate early preliminary diagnosis and treatment. We systematically reviewed prediction models for health care-associated bloodstream infection (HABSI) in neonates, identified superior models, and pooled clinical predictors.

DATA SOURCES

LibHub, PubMed, and Web of Science.

METHODS

The studies included designed prediction models for laboratory-confirmed HABSI or sepsis. The target population was a consecutive series of neonates with suspicion of sepsis hospitalized for ≥ 48 hours. Clinical predictors had to be recorded at time of or before culturing. Methodologic quality of the studies was assessed. Data extracted included population characteristics, total suspected and laboratory-confirmed episodes and definition, clinical parameter definitions and odds ratios, and diagnostic accuracy parameters.

RESULTS

The systematic search revealed 9 articles with 12 prediction models representing 1295 suspected and 434 laboratory-confirmed sepsis episodes. Models exhibit moderate-good methodologic quality, large pretest probability range, and insufficient diagnostic accuracy. Random effects meta-analysis showed that lethargy, pallor/mottling, total parenteral nutrition, lipid infusion, and postnatal corticosteroids were predictive for HABSI. Post hoc analysis with low-gestational-age neonates demonstrated that apnea/bradycardia, lethargy, pallor/mottling, and poor peripheral perfusion were predictive for HABSI. Limitations include clinical and statistical heterogeneity.

CONCLUSIONS

Prediction models should be considered as guidance rather than an absolute indicator because they all have limited diagnostic accuracy. Lethargy and pallor and/or mottling for all neonates as well as apnea and/or bradycardia and poor peripheral perfusion for very low birth weight neonates are the most powerful clinical signs. However, the clinical context of the neonate should always be considered.

Insights from the clinical assurance of service reconfiguration in the NHS: the drivers of reconfiguration and the evidence that underpins it – a mixed-methods study

Background

Over the life of the NHS, hospital services have been subject to continued reconfiguration. Yet it is rare for the reconfiguration of clinical services to be evaluated, leaving a deficit in the evidence to guide local reconfiguration of services.

Objectives

The objectives of this research are to determine the current pressures for reconfiguration within the NHS in England and the solutions proposed. We also investigate the quality of evidence used in making the case for change, any key evidence gaps, and the opportunities to strengthen the clinical case for change and how it is made.

Methods

We have drawn on two key sources of evidence. First, we reviewed the reports produced by the National Clinical Advisory Team (NCAT) documenting its reviews of reconfiguration proposals. An in-depth multilevel qualitative analysis was conducted of 123 NCAT reviews published between 2007 and 2012. Second, we carried out a search and synthesis of the literature to identify the key evidence available to support reconfiguration decisions. The findings from this literature search were integrated with the analysis of the reviews to develop a narrative for each specialty and the process of reconfiguration as a whole.

Results

The evidence from the NCAT reviews shows significant pressure to reconfigure services within the NHS in England. We found that the majority of reconfiguration proposals are driving an increasing concentration of hospital services, with some accompanying decentralisation and, for some specialist services, the development of supporting clinical networks. The primary drivers of reconfiguration have been workforce (in particular the medical workforce) and finance. Improving outcomes and safety issues have been subsidiary drivers, though many make the link between staffing and clinical safety. Policy has also been a notable driver. Access has been notable by its absence as a driver. Despite significant pressures to reconfigure services, many proposals fail to be implemented owing to public and/or clinical opposition. We found strong evidence that some specialist service reconfiguration including vascular surgery and major trauma can significantly improve clinical outcomes. However, there are notable evidence gaps. The most significant is the absence of evidence that service reconfiguration can deliver significant savings. There is also an absence of evidence about safe staffing models and the interplay between staff numbers, skill mix and outcomes. We found that the advice provided by the NCAT reflects the current evidence, but one of the NCAT’s most valuable contributions has been to encourage greater clinical engagement in service change.

Conclusions

The NHS is continuing to concentrate many district general hospital services to resolve financial and workforce pressures. However, many proposals are not implemented owing to public opposition. We also found no evidence to suggest that this will deliver the savings anticipated. There is a significant gap in the evidence about safe staffing models and the appropriate balance of junior and senior medical as well as other clinical staff. There is an urgent need to carry out research that will help to fill the current evidence gap. There is also a need to retain some national clinical expertise to work alongside Clinical Senates in supporting local service reconfiguration.

Funding

The National Institute for Health Research Health Services and Delivery Research programme.

Clinical signs and CRP values associated with blood culture results in neonates evaluated for suspected sepsis

AIM

To identify which clinical signs at presentation are most predictive of sepsis subsequently confirmed by blood culture and to investigate whether the predictive power of the clinical signs varies by gestational age.

METHODS

Among 401 newborn infants < 28 days of age with suspected sepsis, nine signs of sepsis and C-reactive protein (CRP) values were prospectively recorded. Logistic regression assessed the association of these signs and laboratory values with a subsequently confirmed diagnosis of sepsis by positive blood culture. The analysis was stratified by gestational age with mutual simultaneous adjustment for the signs and sex.

RESULTS

Five of the nine clinical signs (feeding intolerance, distended abdomen, blood pressure, bradycardia and apnoea), along with CRP were statistically significantly associated with a positive blood culture. After simultaneous adjustment for all of the signs, apnoea, hypotension and CRP were independently predictive of positive blood culture. When the material was stratified by gestational age, differences in the association with positive blood culture were found for bradycardia, tachypnea and irritability/seizures.

CONCLUSION

In this selected population of infants with suspected sepsis, apnoea and hypotension are independently predictive of a confirmed diagnosis, while bradycardia is more predictive among preterm infants and tachypnea among term infants.