Predicting neonatal mortality among very preterm infants: a comparison of three versions of the CRIB score

Comparing different scoring systems for predicting mortality risk in preterm infants: a systematic review and network meta-analysis

Background

This study aimed to compare the predictive values of eight scoring systems (Neonatal Critical Illness Score [NCIS], Neonatal Therapeutical Intervention Score System [NTISS], Clinical Risk Index for Babies [CRIB], Clinical Risk Index for Babies II [CRIB-II], Score for Neonatal Acute Physiology Perinatal Extension [SNAPPE], Score for Neonatal Acute Physiology Perinatal Extension II [SNAPPE-II], Score for Neonatal Acute Physiology [SNAP], and Score for Neonatal Acute Physiology II [SNAP-II]) for the mortality risk among preterm infants.

Methods

The Embase, PubMed, Chinese Biomedical Database, Web of Science, and Cochrane Library databases were searched to collect studies that compared different scoring systems in predicting the mortality risk in preterm infants from database inception to March 2023. Literature screening, data extraction, and bias risk assessment were independently conducted by two researchers. Subsequently, the random-effects model was used for the network meta-analysis.

Results

A total of 19 articles were included, comprising 14,377 preterm infants and 8 scoring systems. Compared to CRIB-II, NCIS, NTISS, SNAP-II, and SNAPPE-II, CRIB demonstrated better predictive efficiency for preterm infant mortality risk (P < 0.05). Relative to CRIB, CRIB-II, and SNAPPE, SNAP-II had worse predictive efficiency for preterm infant mortality risk (P < 0.05). The surface under the cumulative ranking curve of the eight scoring systems was as follows: CRIB (0.980) > SNAPPE (0.718) >SNAP (0.534) >CRIB-II (0.525) >NTISS (0.478) >NCIS (0.422) >SNAPPE-II (0.298) >SNAP-II (0.046).

Conclusion

The CRIB scoring system showed the highest accuracy in predicting preterm infant mortality risk and was simple to perform. Therefore, CRIB selection can be prioritized in clinical practice.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=434731, PROSPERO (CRD42023434731).

A case-based reasoning system for neonatal survival and LOS prediction in neonatal intensive care units: a development and validation study

Early prediction of neonates' survival and Length of Stay (LOS) in Neonatal Intensive Care Units (NICU) is effective in decision-making. We developed an intelligent system to predict neonatal survival and LOS using the "Case-Based Reasoning" (CBR) method. We developed a web-based CBR system based on K-Nearest Neighborhood (KNN) on 1682 neonates and 17 variables for mortality and 13 variables for LOS and evaluated the system with 336 retrospectively collected data. We implemented the system in a NICU to externally validate the system and evaluate the system prediction acceptability and usability. Our internal validation on the balanced case base showed high accuracy (97.02%), and F-score (0.984) for survival prediction. The root Mean Square Error (RMSE) for LOS was 4.78 days. External validation on the balanced case base indicated high accuracy (98.91%), and F-score (0.993) to predict survival. RMSE for LOS was 3.27 days. Usability evaluation showed that more than half of the issues identified were related to appearance and rated as a low priority to be fixed. Acceptability assessment showed a high acceptance and confidence in responses. The usability score (80.71) indicated high system usability for neonatologists. This system is available at http://neonatalcdss.ir/ . Positive results of our system in terms of performance, acceptability, and usability indicated this system can be used to improve neonatal care.

Automatic oxygen control for reducing extremes of oxygen saturation: a randomised controlled trial

OBJECTIVE

The objective of this study was to evaluate the efficacy of the automatic oxygen control (A-Fio₂) in reducing the percentage of time spent in severe hypoxaemia (Spo₂ <80%) in preterm infants for the time period on invasive ventilation and/or nasal continuous positive airway pressure (NCPAP) delivered by AVEA ventilator.

DESIGN

A parallel arm randomised controlled trial.

SETTING

A level-III neonatal intensive care unit.

PATIENTS

Preterm infants (<33 weeks birth gestation) who received invasive ventilation or NCPAP in the first 72 hours of age.

INTERVENTIONS

A-Fio₂ vs manual (M-Fio₂) oxygen control.

OUTCOMES

The primary outcome of the study was percentage of time spent in severe hypoxaemia (Spo₂ <80%).

RESULTS

44 infants were randomised to either A-Fio₂ or M-Fio₂ arm and continued in the study for the period of respiratory support (invasive ventilation and/or NCPAP). The total number of study days in A-Fio2 and M-Fio₂ arm were 194 and 204 days, respectively. The percentage of time spent in Spo₂ <80% was significantly lower with A-Fio₂ compared with M-Fio₂ (median of 0.1% (IQR: 0.07-0.7) vs 0.6% (0.2-2); p=0.03). The number of prolonged episodes (>60 s) of Spo₂ <80% per day was also significantly lower in A-Fio₂ (0.3 (0.0-2) vs 2 (0.6-6); p=0.02).

CONCLUSION

A-Fio₂ was associated with statistically significant reduction in the percentage of time spent in severe hypoxaemia when compared with M-Fio₂ in preterm infants receiving respiratory support.

TRIAL REGISTRATION NUMBER

NCT04223258.

Comparison of CRIB-II with SNAPPE-II for predicting survival and morbidities before hospital discharge in neonates with gestation ≤ 32 weeks: a prospective multicentric observational study

Various studies validated and compared Score for Neonatal Acute Physiology with Perinatal extension-II (SNAPPE-II) and Clinical Risk Index for Babies-II (CRIB-II) admission sickness severity scores for predicting survival, but very few studies compared them for predicting the morbidities in preterm infants. In this multicenter prospective observational study, SNAPPE-II and CRIB-II newborn illness severity scores were compared for predicting mortality and morbidities in infants with gestational age of ≤ 32 weeks. Major morbidities were classified as bronchopulmonary dysplasia, abnormal cranial ultrasound (presence of intraventricular hemorrhage grade III or more or periventricular leukomalacia grade II to IV), and retinopathy of prematurity requiring treatment. Combined adverse outcome was defined as death or any major morbidity. Comparison of the scoring systems was done by area under the curve (AUC) on receiver operating characteristics curve (ROC curve) analysis. A total of 419 neonates who were admitted to 5 participating NICUs were studied. The mortality rate in the study population was 8.8%. Both CRIB-II (AUC: 0.795) and SNAPPE-II (AUC: 0.78) had good predictive ability for in-hospital mortality. For predicting any one of the major morbidities and combined adverse outcome, CRIB-II had better predictive ability than SNAPPE-II with AUC of 0.83 vs. 0.70 and 0.85 vs. 0.74, respectively.

CONCLUSION

In infants with gestational age of ≤ 32 weeks, both CRIB-II and SNAPPE-II are good scoring systems for predicting mortality. CRIB-II, being a simpler scoring system and having better predictive ability for major morbidities and combined adverse outcome, is preferable over SNAPPE-II.

WHAT IS KNOWN

• SNAPPE-II and CRIB-II scores have good predictive ability on in-hospital mortality in preterm neonates.

WHAT IS NEW

• SNAPPE-II and CRIB-II both have good predictive ability for mortality, but CRIB-II has better ability for short-term morbidities related to the prematurity.

Perinatal risk factors for mortality in very preterm infants-A nationwide, population-based discriminant analysis

Aim

To assess the strength of associations between interrelated perinatal risk factors and mortality in very preterm infants.

Methods

Information on all live‐born infants delivered in Sweden at 22–31 weeks of gestational age (GA) from 2011 to 2019 was gathered from the Swedish Neonatal Quality Register, excluding infants with major malformations or not resuscitated because of anticipated poor prognosis. Twenty‐seven perinatal risk factors available at birth were exposures and in‐hospital mortality outcome. Orthogonal partial least squares discriminant analysis was applied to assess proximity between individual risk factors and mortality, and receiver operating characteristic (ROC) curves were used to estimate discriminant ability.

Results

In total, 638 of 8,396 (7.6%) infants died. Thirteen risk factors discriminated reduced mortality; the most important were higher Apgar scores at 5 and 10 min, GA and birthweight. Restricting the analysis to preterm infants <28 weeks’ GA (n = 2939, 16.9% mortality) added antenatal corticosteroid therapy as significantly associated with lower mortality. The area under the ROC curve (the C‐statistic) using all risk factors was 0.86, as determined after both internal and external validation.

Conclusion

Apgar scores, gestational age and birthweight show stronger associations with mortality in very preterm infants than several other perinatal risk factors available at birth.

Biochemical profile of human infant cerebrospinal fluid in intraventricular hemorrhage and post-hemorrhagic hydrocephalus of prematurity

Background

Intraventricular hemorrhage (IVH) and post-hemorrhagic hydrocephalus (PHH) have a complex pathophysiology involving inflammatory response, ventricular zone and cell–cell junction disruption, and choroid-plexus (ChP) hypersecretion. Increased cerebrospinal fluid (CSF) cytokines, extracellular matrix proteins, and blood metabolites have been noted in IVH/PHH, but osmolality and electrolyte disturbances have not been evaluated in human infants with these conditions. We hypothesized that CSF total protein, osmolality, electrolytes, and immune cells increase in PHH.

Methods

CSF samples were obtained from lumbar punctures of control infants and infants with IVH prior to the development of PHH and any neurosurgical intervention. Osmolality, total protein, and electrolytes were measured in 52 infants (18 controls, 10 low grade (LG) IVH, 13 high grade (HG) IVH, and 11 PHH). Serum electrolyte concentrations, and CSF and serum cell counts within 1-day of clinical sampling were obtained from clinical charts. Frontal occipital horn ratio (FOR) was measured for estimating the degree of ventriculomegaly. Dunn or Tukey’s post-test ANOVA analysis were used for pair-wise comparisons.

Results

CSF osmolality, sodium, potassium, and chloride were elevated in PHH compared to control (p = 0.012 − < 0.0001), LGIVH (p = 0.023 − < 0.0001), and HGIVH (p = 0.015 − 0.0003), while magnesium and calcium levels were higher compared to control (p = 0.031) and LGIVH (p = 0.041). CSF total protein was higher in both HGIVH and PHH compared to control (p = 0.0009 and 0.0006 respectively) and LGIVH (p = 0.034 and 0.028 respectively). These differences were not reflected in serum electrolyte concentrations nor calculated osmolality across the groups. However, quantitatively, CSF sodium and chloride contributed 86% of CSF osmolality change between control and PHH; and CSF osmolality positively correlated with CSF sodium (r, p = 0.55,0.0015), potassium (r, p = 0.51,0.0041), chloride (r, p = 0.60,0.0004), but not total protein across the entire patient cohort. CSF total cells (p = 0.012), total nucleated cells (p = 0.0005), and percent monocyte (p = 0.016) were elevated in PHH compared to control. Serum white blood cell count increased in PHH compared to control (p = 0.042) but there were no differences in serum cell differential across groups. CSF total nucleated cells also positively correlated with CSF osmolality, sodium, potassium, and total protein (p = 0.025 − 0.0008) in the whole cohort.

Conclusions

CSF osmolality increased in PHH, largely driven by electrolyte changes rather than protein levels. However, serum electrolytes levels were unchanged across groups. CSF osmolality and electrolyte changes were correlated with CSF total nucleated cells which were also increased in PHH, further suggesting PHH is a neuro-inflammatory condition.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12987-021-00295-8.

Severe Acute Kidney Injury and Mortality in Extremely Low Gestational Age Neonates

BACKGROUND AND OBJECTIVES

AKI is associated with poor short- and long-term outcomes. Questions remain about the frequency and timing of AKI, and whether AKI is a cause of death in extremely low gestational age neonates.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

The Recombinant Erythropoietin for Protection of Infant Kidney Disease Study examines the kidney outcomes of extremely low gestational age neonates enrolled in the Preterm Epo Neuroprotection study, a randomized, placebo-controlled trial of recombinant human erythropoietin. We included 900 of 941 patients enrolled in Preterm Epo Neuroprotection. Baseline characteristics were compared by primary exposure (severe AKI versus none/stage 1 AKI) using unadjusted logistic regression models. Cox regression models estimated the relationship between severe AKI and death after adjustment for potential confounders. Time-dependent AKI was modeled as a binary outcome and a categorical variable by stage of AKI. We fit Cox models using time-dependent AKI status lagged by <7 days before death. Landmark analyses examined the relationship of death with development of severe AKI.

RESULTS

Severe AKI occurred in 168 of 900 (19%, 95% confidence interval, 17% to 20%) neonates, and stage 3 AKI occurred in 60 (7%, 95% confidence interval, 5% to 8%). Stage 3 AKI occurring 7 days before death (hazard ratio, 3.88; 95% confidence interval, 1.26 to 11.96), intraventricular hemorrhage (hazard ratio, 2.01; 95% confidence interval, 1.01 to 3.99) and sepsis (hazard ratio, 2.85; 95% confidence interval, 1.12 to 7.22) were all independently associated with death. Severe AKI occurring 7 days before death (hazard ratio, 2.21; 95% confidence interval, 0.92 to 5.26) was associated with death but not statistically significant. In a landmark analysis, after adjusting for potential confounders, late (after day 14 and before day 28) severe AKI was strongly associated with higher hazard of death (hazard ratio, 4.57; 95% confidence interval, 1.82 to 11.5).

CONCLUSIONS

Severe AKI occurs frequently in extremely low gestational age neonates. Stage 3 AKI is associated with mortality, and this association is present 7 days before death.

Prognostic Models Predicting Mortality in Preterm Infants: Systematic Review and Meta-analysis

CONTEXT

Prediction models can be a valuable tool in performing risk assessment of mortality in preterm infants.

OBJECTIVE

Summarizing prognostic models for predicting mortality in very preterm infants and assessing their quality.

DATA SOURCES

Medline was searched for all articles (up to June 2020).

STUDY SELECTION

All developed or externally validated prognostic models for mortality prediction in liveborn infants born <32 weeks' gestation and/or <1500 g birth weight were included.

DATA EXTRACTION

Data were extracted by 2 independent authors. Risk of bias (ROB) and applicability assessment was performed by 2 independent authors using Prediction model Risk of Bias Assessment Tool.

RESULTS

One hundred forty-two models from 35 studies reporting on model development and 112 models from 33 studies reporting on external validation were included. ROB assessment revealed high ROB in the majority of the models, most often because of inadequate (reporting of) analysis. Internal and external validation was lacking in 41% and 96% of these models. Meta-analyses revealed an average C-statistic of 0.88 (95% confidence interval [CI]: 0.83-0.91) for the Clinical Risk Index for Babies score, 0.87 (95% CI: 0.81-0.92) for the Clinical Risk Index for Babies II score, and 0.86 (95% CI: 0.78-0.92) for the Score for Neonatal Acute Physiology Perinatal Extension II score.

LIMITATIONS

Occasionally, an external validation study was included, but not the development study, because studies developed in the presurfactant era or general NICU population were excluded.

CONCLUSIONS

Instead of developing additional mortality prediction models for preterm infants, the emphasis should be shifted toward external validation and consecutive adaption of the existing prediction models.

A tutorial on calibration measurements and calibration models for clinical prediction models

Our primary objective is to provide the clinical informatics community with an introductory tutorial on calibration measurements and calibration models for predictive models using existing R packages and custom implemented code in R on real and simulated data. Clinical predictive model performance is commonly published based on discrimination measures, but use of models for individualized predictions requires adequate model calibration. This tutorial is intended for clinical researchers who want to evaluate predictive models in terms of their applicability to a particular population. It is also for informaticians and for software engineers who want to understand the role that calibration plays in the evaluation of a clinical predictive model, and to provide them with a solid starting point to consider incorporating calibration evaluation and calibration models in their work. Covered topics include (1) an introduction to the importance of calibration in the clinical setting, (2) an illustration of the distinct roles that discrimination and calibration play in the assessment of clinical predictive models, (3) a tutorial and demonstration of selected calibration measurements, (4) a tutorial and demonstration of selected calibration models, and (5) a brief discussion of limitations of these methods and practical suggestions on how to use them in practice.

Prolonged empiric antibiotics and time to full enteral feed in preterm infants less than 29 weeks of gestational age

BACKGROUND

Early empiric antibiotic exposure appears to negatively influence feeding tolerance in preterm infants. However, the effect of prolonged antibiotic treatment is unknown. The objective of this study was to investigate whether prolonged antibiotics impact the time to full enteral feed in infants less than 29 weeks of gestational age with negative blood cultures.

METHODS

Retrospective data for infants less than 29 weeks gestation age were retrieved from the PEARL-Peristat perinatal registry in Qatar. Exclusion criteria were major congenital anomalies, conditions requiring surgery in the first 10 days of life, positive blood cultures in the first 48 hours of life, and death within the first week of life. Antibiotic courses were categorized as prolonged if continued more than 48 hours. The primary outcome was the duration of total parenteral nutrition.

RESULTS

Of 199 study infants, 185 (92.9%) underwent antibiotic treatment for >  48 hours despite negative blood cultures. The median duration of parenteral nutrition was not significantly different between the prolonged and short antibiotic groups (25 and 22 days, respectively; p = 0.139). Infants with prolonged antibiotic courses experienced non-significantly higher levels of necrotizing enterocolitis (7.1% and 18.4%, respectively), bronchopulmonary dysplasia (28.6% and 45.4%, respectively), and retinopathy of prematurity (14.3% and 38.4%, respectively). There were no differences in the late-onset sepsis rate (78.6% and 82.1%, respectively) and the in-hospital death rate (7.1% and 7.6%, respectively).

CONCLUSIONS

Prolonged antibiotic treatment in infants less than 29 weeks gestation with negative blood cultures has no significant impact on the time to full enteral feed.

The CRIB II (Clinical Risk Index for Babies II) Score in Prediction of Neonatal Mortality

Predicting the outcome of neonatal critical patients remains elusive. The multiple factors of maternal state of health (infections, diabetes, gestosis), the placental situation (premature rupture of membranes) as well as multiple factors from the baby (small for gestational age, low Apgar score, low birth infections, mechanical ventilation, hypoglycaemia hyperglycamiea) render the approach to treatment of each patient individual and the outcome uncertain. Several approaches and scales are developed in order to assess the mortality risk in those rather complicated situations.We used the CRIB-II scale to assess the mortality risk in 80 patients delivered in a large tertiary level hospital with more than 4,000 deliveries yearly. The patients were stratified according to all the neonatal risk factors and comorbidities. The CRIB-II scale identified well the mortality rates, but not the outcomes. A large and well-balanced cohort of patients followed for a longer period is required to discern in detail the importance of CRIB-II scale in predicting outcomes in high-risk new-borns. This could serve as an assistance to personalized approach to severely sick children. In addition, it is a valuable method in comparing outcomes in different NICUs and outcomes in different times in the same NICU, thus rendering possible improvements in the same unit and among several NICU departments.

Comparing mortality risk models in VLBW and preterm infants: systematic review and meta-analysis

OBJECTIVE

To compare the prognostic accuracy of six neonatal illness severity scores (CRIB, CRIB II, SNAP, SNAP II, SNAP-PE, and SNAP-PE II), birthweight (BW), and gestational age (GA) for predicting pre-discharge mortality among very low birth weight (VLBW) infants (<1500 g) and very preterm infants (<32 weeks' gestational age).

STUDY DESIGN

PubMed, EMBASE, and Scopus were the data sources searched for studies published before January 2019. Data were extracted, pooled, and analyzed using random-effects models and reported as AUC with 95% confidence intervals (CI).

RESULTS

Of 1659 screened studies, 24 met inclusion criteria. CRIB was the most discriminate for predicting pre-discharge mortality [AUC 0.88 (0.86-0.90)]. GA was the least discriminate [AUC 0.76 (0.72-0.80)].

CONCLUSIONS

Although the original CRIB score was the most accurate predictor of pre-discharge mortality, significant heterogeneity between studies lowers confidence in this pooled estimate. A more precise illness severity score to predict pre-discharge mortality is still needed.

Admissions and mortality over a 5-year period in a limited-resource neonatal unit in Ghana

Objective

To review admissions and deaths at the neonatal intensive care unit (NICU) of the Korle Bu Teaching Hospital (KBTH), Ghana from 2011 to 2015, for the purposes of documentation of outcomes and identification of areas for improvement.

Design

A retrospective descriptive study of NICU Admissions & Discharges from 2011 to 2015. All data in the NICU Admissions & Discharge books were transferred into a spreadsheet and analysed.

Setting

The NICU of KBTH provides secondary and tertiary care for premature and critically ill term babies in the southern half of Ghana.

Results

Over the 5-year period, 9213 babies were admitted to the NICU. Admission weights ranged from 300 to 6700g with median of 2400g. Overall mortality rate was 19.2%. Mortality rates were progressively and significantly higher in babies with lower admission weights and earlier gestations.

Conclusions

We report a high NICU mortality rate of 19.2%, compared to the worldwide range of 3.1% to 29%. This wide range of outcomes is attributable to differences in the severity of illness of patients and to the organisation of resources devoted to obstetric and neonatal care. To substantially improve perinatal and neonatal outcomes, there is a need for wider coverage and better quality of health care; and to consider rationing of care. Complex interventions are necessary to improve outcomes, not just an increase in the allocation of particular resources.

Funding

None declared.

Subjective and Objective Measurement of Neonatal Nurse Practitioner Workload

BACKGROUND

Neonatal nurse practitioner (NNP) workload is not well studied, and metrics specific to NNP practice are lacking. Factors such as changes in resident duty hours, increasing neonatal intensive care unit admissions, and a shortage of NNPs contribute to NNP workload. Increased workload has been shown to be detrimental to providers and can affect quality of care.

PURPOSE

This study quantified NNP workload using a subjective workload metric, the NASA Task Load Index, and a newly developed objective workload metric specific to NNP practice.

METHODS

The NNP group at a level IV academic medical center was studied. The sample included 22 NNPs and 47 workload experiences.

RESULTS

A comparison of scores from the NASA Task Load Index and objective workload metric showed a moderate correlation (r = 0.503). Mental demand workload scores had the highest contribution to workload. Feelings of frustration also contributed to workload.

IMPLICATIONS FOR PRACTICE

The NASA Task Load Index can be utilized to measure the workload of NNPs. The objective workload metric has potential to quantify NNP workload pending further validation studies and is a simple, straightforward tool.

IMPLICATIONS FOR RESEARCH

Additional research is needed regarding NNP workload and methods to quantify workload. Larger studies are needed to validate the objective workload metric.

Comparing very low birth weight versus very low gestation cohort methods for outcome analysis of high risk preterm infants

Background

Compared to very low gestational age (<32 weeks, VLGA) cohorts, very low birth weight (<1500 g; VLBW) cohorts are more prone to selection bias toward small-for-gestational age (SGA) infants, which may impact upon the validity of data for benchmarking purposes.

Method

Data from all VLGA or VLBW infants admitted in the 3 Networks between 2008 and 2011 were used. Two-thirds of each network cohort was randomly selected to develop prediction models for mortality and composite adverse outcome (CAO: mortality or cerebral injuries, chronic lung disease, severe retinopathy or necrotizing enterocolitis) and the remaining for internal validation. Areas under the ROC curves (AUC) of the models were compared.

Results

VLBW cohort (24,335 infants) had twice more SGA infants (20.4% vs. 9.3%) than the VLGA cohort (29,180 infants) and had a higher rate of CAO (36.5% vs. 32.6%). The two models had equal prediction power for mortality and CAO (AUC 0.83), and similarly for all other cross-cohort validations (AUC 0.81–0.85). Neither model performed well for the extremes of birth weight for gestation (<1500 g and ≥32 weeks, AUC 0.50–0.65; ≥1500 g and <32 weeks, AUC 0.60–0.62).

Conclusion

There was no difference in prediction power for adverse outcome between cohorting VLGA or VLBW despite substantial bias in SGA population. Either cohorting practises are suitable for international benchmarking.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0921-x) contains supplementary material, which is available to authorized users.

Early Heart Rate Characteristics Predict Death and Morbidities in Preterm Infants

OBJECTIVES

To determine whether an early heart rate characteristics (HRC) index (HeRO score), measured in the first day and week after birth predicts death and morbidities compared with established illness severity scores.

STUDY DESIGN

For all very low birth weight infants in a single neonatal intensive care unit from 2004-2014, the average first day HRC index was calculated within 24 hours of birth (aHRC-24h) and the average first week HRC index within 7 days of birth (aHRC-7d). The Score for Neonatal Acute Physiology (SNAP-II) and Clinical Risk Indicator for Babies (CRIB-II) were calculated when data were available. The aHRC was compared with the SNAP-II and CRIB-II for predicting death, late-onset septicemia, necrotizing enterocolitis, bronchopulmonary dysplasia, severe intraventricular hemorrhage, or severe retinopathy of prematurity.

RESULTS

All 4 scores were associated with death and severe intraventricular hemorrhage (P < .01). The OR and 95% CI for every 1-point increase in aHRC for predicting mortality, adjusted for gestational age, was 1.59 (1.25-2.00) for aHRC-24h and 2.61 (1.58-4.33) for aHRC-7d. High aHRC-7d, SNAP-II, and CRIB-II were associated with bronchopulmonary dysplasia (P < .001). High aHRC-7d was associated with late-onset septicemia (P < .05). None of the scores predicted necrotizing enterocolitis or severe retinopathy of prematurity.

CONCLUSIONS

HRC assessed in the first day or first week after birth compares favorably to established risk scores to predict death and morbidities in very low birth weight infants.

Right cot, right place, right time: improving the design and organisation of neonatal care networks – a computer simulation study

Background

There is a tension in many health-care services between the expertise and efficiency that comes with centralising services and the ease of access for patients. Neonatal care is further complicated by the organisation of care into networks where different hospitals offer different levels of care and where capacity across, or between, networks may be used when local capacity is exhausted.

Objectives

To develop a computer model that could mimic the performance of a neonatal network and predict the effect of altering network configuration on neonatal unit workloads, ability to meet nurse staffing guidelines, and distance from the parents’ home location to the point of care. The aim is to provide a model to assist in planning of capacity, location and type of neonatal services.

Design

Descriptive analysis of a current network, economic analysis and discrete event simulation. During the course of the project, two meetings with parents were held to allow parent input.

Setting

The Peninsula neonatal network (Devon and Cornwall) with additional work extending to the Western network.

Main outcome measures

Ability to meet nurse staffing guidelines, cost of service provision, number and distance of transfers, average travel distances for parents, and numbers of parents with an infant over 50 km from home.

Data sources

Anonymised neonatal data for 7629 infants admitted into a neonatal unit between January 2011 and June 2013 were accessed from Badger patient care records. Nurse staffing data were obtained from a daily ring-around audit. Further background data were accessed from NHS England general practitioner (GP) Practice Profiles, Hospital Episode Statistics, Office for National Statistics and NHS Connecting for Health. Access to patient care records was approved by the Research Ethics Committee and the local Caldicott Guardian at the point of access to the data.

Results

When the model was tested against a period of data not used for building the model, the model was able to predict the occupancy of each hospital and care level with good precision (R2 > 0.85 for all comparisons). The average distance from the parents’ home location (GP location used as a surrogate) was predicted to within 2 km. The number of transfers was predicted to within 2%. The model was used to forecast the effect of centralisation. Centralisation led to reduced nurse requirements but was accompanied by a significant increase in parent travel distances. Costs of nursing depend on how much of the time nursing guidelines are to be met, rising from £4500 per infant to meet guidelines 80% of the time, to £5500 per infant to meet guidelines 95% of the time. Using network capacity, rather than local spare capacity, to meet local peaks in workloads can reduce the number of nurses required, but the number of transfers and the travel distance for parents start to rise significantly above ≈ 70% network capacity utilisation.

Conclusions

We have developed a model that predicts performance of a neonatal network from the perspectives of both the service provider and the parents of infants in care.

Future work

Application of the model at a national level.

Funding

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

Cerebrospinal fluid levels of amyloid precursor protein are associated with ventricular size in post-hemorrhagic hydrocephalus of prematurity

Background

Neurological outcomes of preterm infants with post-hemorrhagic hydrocephalus (PHH) remain among the worst in infancy, yet there remain few instruments to inform the treatment of PHH. We previously observed PHH-associated elevations in cerebrospinal fluid (CSF) amyloid precursor protein (APP), neural cell adhesion molecule-L1 (L1CAM), neural cell adhesion molecule-1 (NCAM-1), and other protein mediators of neurodevelopment.

Objective

The objective of this study was to examine the association of CSF APP, L1CAM, and NCAM-1 with ventricular size as an early step toward developing CSF markers of PHH.

Methods

CSF levels of APP, L1CAM, NCAM-1, and total protein (TP) were measured in 12 preterm infants undergoing PHH treatment. Ventricular size was determined using cranial ultrasounds. The relationships between CSF APP, L1CAM, and NCAM-1, occipitofrontal circumference (OFC), volume of CSF removed, and ventricular size were examined using correlation and regression analyses.

Results

CSF levels of APP, L1CAM, and NCAM-1 but not TP paralleled treatment-related changes in ventricular size. CSF APP demonstrated the strongest association with ventricular size, estimated by frontal-occipital horn ratio (FOR) (Pearson R = 0.76, p = 0.004), followed by NCAM-1 (R = 0.66, p = 0.02) and L1CAM (R = 0.57,p = 0.055). TP was not correlated with FOR (R = 0.02, p = 0.95).

Conclusions

Herein, we report the novel observation that CSF APP shows a robust association with ventricular size in preterm infants treated for PHH. The results from this study suggest that CSF APP and related proteins at once hold promise as biomarkers of PHH and provide insight into the neurological consequences of PHH in the preterm infant.

Prospective surveillance of antibiotic use in the neonatal intensive care unit: results from the SCOUT study

BACKGROUND

Prolonged or unnecessary antibiotic use is associated with adverse outcomes in neonates. Our objectives were to quantify all antibiotic use in a Level-III neonatal intensive care unit and to identify scenarios where their use could be reduced.

METHODS

Surveillance and evaluation of all antibiotic use provided to every infant admitted to a Level-III neonatal intensive care unit from 10/3/11 to 11/30/12 was performed. Types of antibiotics, reasons for their initiation, discontinuation and duration, as well as clinical, laboratory and outcome data were recorded. Antibiotic use was quantified by days of therapy (DOT) per 1000 patient-days (PD).

RESULTS

A total of 1607 infants were included. The total antibiotic use was 9165 DOT (343.2 DOT/1000 PD; 5.7 DOT/infant). Seventy-two percent of infants received 1 (43%) or more (29%) courses of antibiotics. Gentamicin (46%), ampicillin (39%) and oxacillin (8%) were the most frequently used agents. Ninety-four percent of antibiotic use (323 DOT/1000 PD) was empiric therapy for suspected infection. Sixty-three percent (216.2 DOT/1000 PD) was discontinued at approximately 48 hours when cultures were sterile (68%>48 hours, 32%≤48 hours). Twenty-six percent of all antibiotic use (89.4 DOT/1000 PD) was therapy for ≥5 days despite sterile cultures; pneumonia (16%) and "culture-negative" sepsis (8%) were the major contributors. Five percent (17.4 DOT/1000 PD) of antibiotic use was for culture-proven sepsis, 5% (16.6 DOT/1000 PD) was penicillin prophylaxis for group B Streptococcus and 1% (3.5 DOT/1000 PD) was preprocedural prophylaxis.

CONCLUSIONS

Narrow-spectrum therapy accounted for >92% of antibiotic use and would not be monitored by most stewardship programs. Only 5% of antibiotic usage was due to culture-proven infection. Pneumonia and "culture-negative" sepsis were frequent reasons for prolonged therapy; further study of these conditions may allow reduction in treatment duration.

Antimicrobial stewardship in the NICU

There are unique challenges to antimicrobial stewardship in neonatal intensive care units (NICUs). Diagnosis of infection is difficult as neonates can have nonspecific signs and symptoms. Between and within NICUs, significant variation exists in the treatment duration of suspected sepsis and pneumonia. Development of multidisciplinary teams and meaningful metrics are essential for sustainable antibiotic stewardship. Potential stewardship interventions include optimizing culturing techniques, guiding empiric therapy by NICU-specific antibiograms, using ancillary laboratory tests, and promptly discontinuing therapy once infection is no longer suspected. Use of large neonatal databases can be used to benchmark antibiotic use and conduct comparative effectiveness research.

Auditing Neonatal Intensive Care: Is PREM a Good Alternative to CRIB for Mortality Risk Adjustment in Premature Infants?

BACKGROUND

Comparing outcomes at different neonatal intensive care units (NICUs) requires adjustment for intrinsic risk. The Clinical Risk Index for Babies (CRIB) is a widely used risk model, but it has been criticized for being affected by therapeutic decisions. The Prematurity Risk Evaluation Measure (PREM) is not supposed to be prone to treatment bias, but has not yet been validated.

OBJECTIVES

We aimed to validate the PREM, compare its accuracy to that of the original and modified versions of the CRIB and CRIB-II, and examine the congruence of risk categorization.

METHODS

Very-low-birth-weight (VLBW) infants with a gestational age (GA) <33 weeks, who were admitted to NICUs in Baden-Württemberg from 2003 to 2008, were identified from the German neonatal quality assurance program. CRIB, CRIB-II and PREM scores were calculated and modified. Omitting variables that directly reflected therapeutic decisions [the applied fraction of inspired oxygen (FiO2)] or that may have been prone to early-treatment bias (base excess and temperature), non-NICU-therapy-influenced scores were obtained. Score performance was assessed by the area under their ROC curve (AUC).

RESULTS

The CRIB showed the largest AUC (0.89), which dropped significantly (to 0.85) after omitting the FiO2. The PREM birth condition model, PREM(bcm) (AUC 0.86), and the PREM birth model, PREM(bm) (AUC 0.82), also demonstrated good discrimination. PREM(bm) was superior to other non-therapy-affected scores and to GA, particularly in infants with <750 g birth weight. Congruence of risk categorization was low, especially among higher-risk cases.

CONCLUSIONS

The CRIB score had the largest AUC, resulting from its inclusion of FiO2. PREM(bm), as the most accurate score among those unaffected by early treatment, seems to be a good alternative for strict risk adjustment in NICU auditing. It could be useful to combine scores.

Heart rate passivity of cerebral tissue oxygenation is associated with predictors of poor outcome in preterm infants

AIM

Near-infrared spectroscopy (NIRS) and transcranial Doppler (TCD) allow non-invasive assessment of cerebral haemodynamics. We assessed cerebrovascular reactivity in preterm infants by investigating the relationship between NIRS- and TCD-derived indices and correlating them with severity of clinical illness.

METHODS

We recorded the NIRS-derived cerebral tissue oxygenation index (TOI) and TCD-derived flow velocity (Fv), along with other physiological variables. Moving correlation coefficients between measurements of cerebral perfusion (TOI, Fv) and heart rate were calculated. We presumed that positivity of these correlation coefficients - tissue oxygenation heart rate reactivity index (TOHRx) and flow velocity heart rate reactivity index (FvHRx) - would indicate a direct relationship between cerebral perfusion and cardiac output representing impaired cerebrovascular autoregulation.

RESULTS

We studied 31 preterm infants at a median age of 2 days, born at a median gestational age of 26 + 1 weeks. TOHRx was significantly correlated with gestational age (R = -0.57, p = 0.007), birth weight (R = -0.58, p = 0.006) and the Clinical Risk Index for Babies II (R = 0.55, p = 0.0014). TOHRx and FvHRx were significantly correlated (R = 0.39, p = 0.028).

CONCLUSION

Heart rate has a key influence on cerebral haemodynamics in preterm infants, and TOHRx may be of diagnostic value in identifying impaired cerebrovascular reactivity leading to adverse clinical outcome.

Use of Rotterdam CT scores for mortality risk stratification in children with traumatic brain injury

OBJECTIVES

The Rotterdam CT score refined features of the Marshall score and was designed to categorize traumatic brain injury type and severity in adults. The objective of this study was to determine whether the Rotterdam CT score can be used for mortality risk stratification after pediatric traumatic brain injury.

DESIGN

In children with moderate to severe traumatic brain injury, a comparison of observed versus predicted mortality was calculated using published model probabilities of adult mortality. Development and validation of a new pediatric mortality model using randomly selected prediction and validation samples from our cohort.

SETTING

A single level 1 pediatric trauma center.

SUBJECTS

Six hundred thirty-two children with moderate or severe traumatic brain injury.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Sixteen percent of the patients (101 of 632) died prior to hospital discharge. The predicted mortality based on Rotterdam score for adults with moderate or severe traumatic brain injury discriminated pediatric observed mortality well (area under the curve = 0.85; 95% CI, 0.80-0.89) but had poor calibration, overestimating or underestimating mortality for children in several Rotterdam categories. A predictive model based on children with moderate or severe traumatic brain injury from the single center discriminated mortality well (area under the curve, 0.80; 95% CI, 0.68-0.91) and showed good calibration and overall fit.

CONCLUSIONS

Children with traumatic brain injury have better survival than adults in Rotterdam CT score categories representing less severe injuries but worse survival than adults in higher score categories. A novel, validated pediatric mortality model based on the Rotterdam score is accurate in children with moderate or severe traumatic brain injury and can be used for risk stratification.

Nationwide inventory of risk factors for retinopathy of prematurity in the Netherlands

OBJECTIVES

To study the incidence and risk factors for retinopathy of prematurity (ROP) in the Netherlands.

STUDY DESIGN

Prospective, approximating population-based study that included infants with gestational age (GA) <32 weeks and/or birth weight (BW) <1500 g born in 2009. Pediatricians and ophthalmologists of all hospitals involved in care for premature infants reported data that were matched with the national perinatal database for risk factor analysis.

RESULTS

Of 1380 infants, median GA 29.8 weeks (IQR 28.1-31.1) and median BW 1260 g (IQR 1020-1500), ROP developed in 21.9%. Logistic regression identified GA and BW as risk factors for ROP (P < .001). After adjustment for GA and BW, additional risk factors were inhaled nitric oxide (iNO; OR 2.6, 95% CI 1.1-6.2, P = .03), stay at a neonatal intensive care unit >28 days (OR 1.6, 95% CI 1.1-2.6, P = .03), and artificial ventilation >7 days (OR 1.6, 95% CI 1.1-2.5, P = .02). Prenatal glucocorticoids (OR 0.6, 95% CI 0.4-0.8, P < .001) and female sex (OR 0.7, 95% CI 0.5-0.99, P = .04) showed a lesser incidence of ROP. iNO remained significant after correction for all significant factors (OR 2.6, 95% CI 1.1-6.2, P = .03).

CONCLUSION

In addition to established risk factors (GA, BW, stay at a neonatal intensive care unit >28 days, and artificial ventilation >7 days), treatment with iNO as risk factor for ROP is a novel finding.

Use of risk stratification indices to predict mortality in critically ill children

The complexity and high cost of neonatal and pediatric intensive care has generated increasing interest in developing measures to quantify the severity of patient illness. While these indices may help improve health care quality and benchmark mortality across hospitals, comprehensive understanding of the purpose and the factors that influenced the performance of risk stratification indices is important so that they can be compared fairly and used most appropriately. In this review, we examined 19 indices of risk stratification used to predict mortality in critically ill children and critically analyzed their design, limitations, and purposes. Some pediatric and neonatal models appear well-suited for institutional benchmarking purposes, with relatively brief data acquisition times, limited potential for treatment-related bias, and reliance on diagnostic variables that permit adjustment for case mix. Other models are more suitable for use in clinical trials, as they rely on physiologic variables collected over an extended period, to better capture the interaction between organ systems function and specific therapeutic interventions in acutely ill patients. Irrespective of their clinical or research applications, risk stratification indices must be periodically recalibrated to adjust for changes in clinical practice in order to remain valid outcome predictors in pediatric intensive care units. Longitudinal auditing, education, training, and guidelines development are also critical to ensure fidelity and reproducibility in data reporting.

CONCLUSION

Risk stratification indices are valid tools to describe intensive care unit population and explain differences in mortality.

Comparison of four methods for deriving hospital standardised mortality ratios from a single hierarchical logistic regression model

There is interest in deriving case-mix adjusted standardised mortality ratios so that comparisons between healthcare providers, such as hospitals, can be undertaken in the controversial belief that variability in standardised mortality ratios reflects quality of care. Typically standardised mortality ratios are derived using a fixed effects logistic regression model, without a hospital term in the model. This fails to account for the hierarchical structure of the data - patients nested within hospitals - and so a hierarchical logistic regression model is more appropriate. However, four methods have been advocated for deriving standardised mortality ratios from a hierarchical logistic regression model, but their agreement is not known and neither do we know which is to be preferred. We found significant differences between the four types of standardised mortality ratios because they reflect a range of underlying conceptual issues. The most subtle issue is the distinction between asking how an average patient fares in different hospitals versus how patients at a given hospital fare at an average hospital. Since the answers to these questions are not the same and since the choice between these two approaches is not obvious, the extent to which profiling hospitals on mortality can be undertaken safely and reliably, without resolving these methodological issues, remains questionable.

Prognostic models for stillbirth and neonatal death in very preterm birth: a validation study

OBJECTIVES

To validate externally 2 prognostic models for stillbirth and neonatal death in very preterm infants who are either known to be alive at the onset of labor or admitted for neonatal intensive care.

PATIENTS AND METHODS

All infants, with gestational age 22 to 32 weeks, of European ethnicity, known to be alive at the onset of labor (n = 17 582) and admitted for neonatal intensive care (n = 11 578), who were born in the Netherlands between January 1, 2000, and December 31, 2007. The main outcome measures were stillbirth or death within 28 days for infants known to be alive at the onset of labor and death before discharge from the NICU for infants admitted for intensive care. Model performance was studied with calibration plots and c statistic.

RESULTS

Of the infants known to be alive at the onset of labor, 16.7% (n = 2939) died during labor or within 28 days of birth, and 7.8% (n = 908) of the infants admitted for neonatal intensive care died before discharge from intensive care. The prognostic model for infants known to be alive at the onset of labor showed good calibration and excellent discrimination (c statistic 0.92). The prognostic model for infants admitted for neonatal intensive care showed good calibration and good discrimination (c statistic 0.82).

CONCLUSIONS

The 2 prognostic models for stillbirth and neonatal death in very preterm Dutch infants showed good performance, suggesting their use in clinical practice in the Netherlands and possibly other Western countries.

Transition from curative efforts to purely palliative care for neonates: does physiology matter?

OBJECTIVE

To isolate the threshold point in which the goal of care for an infant with life-limiting conditions transitions from curative efforts to purely palliative care.

DESIGN

Descriptive Web-based survey of 285 neonatal physicians and nurses who had participated in care of dying infants.

METHOD

Researcher-developed tool measured multiple palliative care concepts related to transition to purely palliative care, such as identification of infants for whom purely palliative care should be offered; physician and nurse satisfaction with and barriers to the transition process; physiological factors that indicated that the infant was ready for transition to purely palliative care; publication knowledge to guide palliative care; and factors influencing decision making.

RESULTS

The study aim was to identify the physiology involved in coming to the end of life and indicating a transition need for palliative care. But although the respondents were able to identify physiological factors or lethal conditions leading to a transition to purely palliative care, they stated that these factors were not how the goals of care were established. Respondents (96%) stated that parental agreement was the determinant to palliative care transition, and, regardless of neonatal physiological condition, without agreement, curative technological efforts continued. Respondents felt that more education on the palliative care process for both staff and families was necessary to move dignified end-of-life care forward.

CONCLUSIONS

Parents must be our partners when the burden of care to the infant is greater than the benefit. Suggestions to assist both parents and providers are offered.

CLINICAL RELEVANCE

Although this study is based on end-of-life decision making for newborns, the findings may resonate to nurses who care for dying patients of any age group, with any diagnosis, cared for in any type of medical-surgical or critical care unit. The findings describe the American concept of patient and family autonomy and problems that have arisen from the implementation of autonomy in end-of-life decision making regarding withholding/withdrawing therapies that provide artificial life support.