The HeRO score: Enhancing prognosis and predicting nosocomial infections in newborns: Insights from the neonatal intensive care unit

1 Introduction

HeRO (Heart Rate Observation) monitoring is a specialized technology used in the Neonatal Intensive Care Unit (NICU) to reduce mortality and improve outcomes in critically ill infants. It is a non-invasive method of monitoring a baby’s heart rate continuously, allowing for early detection of significant changes or abnormalities in heart rate patterns [1].

The purpose of HeRO monitoring is to identify infants who are at high risk of deteriorating or experiencing adverse events, such as apnea (temporary cessation of breathing) or bradycardia (abnormally slow heart rate < 120 bpm). These events can be indicators of significant illness or distress in NICU patients and may lead to severe consequences if not promptly addressed.

HeRO monitoring uses electrodes placed on the infant’s chest to measure electrical impulses generated by the heart. The system analyzes the heart rate patterns in real-time and provides visual and auditory alarms to alert healthcare providers of any concerning changes. These alarms can help medical staff intervene quickly to stabilize the infant’s condition, administer appropriate treatment, and prevent further deterioration [2].

The key benefit of HeRO monitoring is its ability to detect subtle changes in heart rate patterns that may not be apparent during intermittent spot checks. By providing continuous monitoring, it offers a more comprehensive picture of the infant’s cardiac status and allows for early intervention, potentially reducing the risk of adverse outcomes and mortality.

It’s important to note that while HeRO monitoring can be a valuable tool in the NICU, it is typically used in combination with other vital sign monitoring systems and clinical assessments. The data provided by HeRO monitoring should be interpreted alongside other clinical information to guide medical decision-making.

Overall, HeRO monitoring plays a significant role in improving patient safety and outcomes in the NICU by enabling early detection and intervention for infants at high risk of adverse events related to their heart rate.

The objectives of our work were to:

Evaluate the importance of the hero score in the early detection of nosocomial infection.

2 Patients and methods

This study is a prospective observational and descriptive study, including 100 cases admitted to the neonatology department of Marrakech University Hospital. The data will be collected using a pre-designed data collection form which will include basic patient demographics, maternal and neonatal characteristics, diagnosis, laboratory results, treatment type, and outcomes.

Marrakech University Hospital is a tertiary care hospital in Morocco that provides specialized medical care services to the local population. Neonatal admissions in this hospital cover a broad range of diagnoses and complications. To improve the quality of care and support public health policies, it is essential to describe the characteristics of neonatal cases admitted to the hospital over a period of ten months from September 2020 to June 2021.

3 Results

The total number of neonatal admissions during the study period was 1,250, and 100 neonates met the inclusion criteria. We noted a clear male predominance with a frequency of 61%, a sex ratio of: 1.56(M/F).

The mean weight of the neonates was 2.78±0.67 Kg, and the mean gestational age was 37.5±2.8 weeks. There is a predominance of premature babies, with 51% of all newborns being premature. Among premature babies, those born with a gestational age higher than 32 weeks had a higher frequency (64%) compared to those born with a gestational age lower than 32 weeks (35%). The remaining 49% of newborns were born at term.

The most common diagnosis was respiratory distress syndrome (24%), followed by hyperbilirubinemia (18%) and neonatal sepsis (16%).

The neonates were hospitalized primarily for pulmonary and neonatal infections, with perinatal asphyxia being a common factor. When they were hospitalized, 37% of the neonates presented with mottling, which is a discoloration of the skin, and 32% had a rise in CRT (capillary refill time) > 3 s, indicating poor blood flow. Additionally, 24% of the neonates had a greyish complexion.

A total of 56 newborns were under CPAP (Continuous Positive Airway Pressure) with an average duration of 10 days. 25 newborns were intubated with an average duration of 2 days.

8 newborns were on oxygen therapy. 11 newborns were without ventilatory support.

The Hero score was elevated 24 hours before the onset of clinical signs in the majority of cases (52%). (Table 1)

Positive blood cultures were observed in 91% of the cases under consideration, indicating the presence of bacterial infection in the bloodstream. Among the positive cultures, Klebsiella pneumoniae was the predominant bacterium, accounting for 51% of the cases (Table 2).

The mean length of hospital stay was 9.5±6.8 days, and the overall mortality rate was 6%. and died due to either heart disease, severe nosocomial infection, or sepsis.

Trends, hard limits, and alarms have been used for years to signal that a patient is currently deteriorating. HeRO is different. HeRO identifies subtle irregularities in heart rate variability that occur hours and days prior to patient deterioration and provides an early warning of patient distress, including sepsis, Necrotizing enterocolitis, meningitis, respiratory decompensation, brain pathology, and death1. And unlike any other monitoring technology available, HeRO has been proven in the most rigorous scientific fashion to improve survival.

Released very early in infection, cytokines are the mediators of the inflammatory response. They have effects throughout the body, including the way the pacemaker of the heart responds to the autonomic nervous system. During the early stage of infection and other inflammatory events, characteristic abnormal heart rate patterns occur that HeRO has been trained to identify, and HeRO renders a score every hour that is the risk of infection in the next 24 hours.

There is a large body of literature demonstrating that delays in antibiotic administration can increase mortality and morbidity. Researchers hypothesized that by improving the timing of the diagnosis, HeRO monitoring might improve outcomes for NICU patients.

The early detection of neonatal sepsis, which is a systemic infection in newborns caused by bacteria, viruses, or fungi; is important in neonatology. Detecting sepsis early allows for prompt administration of supportive therapies and antibiotics, leading to improved outcomes. However, early detection can be challenging due to subtle and nonspecific clinical signs in the early phase of sepsis.

To address this challenge, the HeRO (heart rate observation) monitor was developed. It was observed that during the early phase of sepsis, subtle but complex alterations in heart rate characteristics occur. These alterations include a decrease in heart rate variability and the presence of transient heart rate decelerations, which are also seen in fetuses exposed to asphyxia. These changes can be detected by the HeRO monitor before overt clinical manifestations of sepsis are apparent, which may not be visible with standard cardiorespiratory monitoring [3].

The HeRO monitor provides a numerical score that predicts the risk of a patient experiencing clinical deterioration coinciding with clinical or culture-proven sepsis within the next 24 hours. This score helps in identifying neonates at risk for sepsis and enables early intervention, leading to better management and outcomes.

The study mentioned in the passage aimed to evaluate the effectiveness of the HeRO score in differentiating between septic and non-septic preterm neonates. Additionally, it aimed to assess the ability of the HeRO score to predict the development of neonatal sepsis in preterm neonates. The findings of this study would contribute to early intervention and improved management of neonatal sepsis in preterm neonates [4].

In summary, the passage highlights the significance of early detection of neonatal sepsis and introduces the HeRO monitor as a tool for detecting subtle alterations in heart rate characteristics associated with sepsis before clinical signs are evident. The HeRO score derived from the monitor can help differentiate between septic and non-septic preterm neonates and predict the development of sepsis, enabling timely intervention and improved outcomes.

The excerpt you provided discusses the use of HeRO (Heart rate Observation) scores in interpreting the health status of very sick neonatal intensive care unit (NICU) patients. HeRO scores are used to monitor the health of infants, particularly those with severe lung or brain issues, who are also at high risk for sepsis (a potentially life-threatening infection).

In some cases, these NICU patients may experience frequent large peaks in their HeRO scores throughout the week, which may not necessarily be indicative of sepsis. Therefore, the challenge for clinicians is to understand how to interpret the HeRO score in such patients who have a history of multiple spikes unrelated to sepsis [5].

To address this challenge, clinicians may establish a “stable baseline” for each patient. This baseline represents the normal range of HeRO scores for that specific patient, considering their individual health condition and history. By establishing this baseline, clinicians can identify any significant abrupt rise in the HeRO score beyond the patient’s normal range.

When a large and sudden increase in the HeRO score occurs over the established baseline, clinicians can combine this information with clinical signs and laboratory findings suggestive of infection to make decisions about further diagnostic measures, such as obtaining cultures and initiating antibiotic treatment if necessary.

The excerpt also suggests that incorporating additional biomarker testing, such as C-reactive protein (CRP) or a cytokine assay (if available), alongside the HeRO screening, may enhance the diagnostic usefulness of the HeRO score in making decisions regarding the initiation or discontinuation of antibiotics in these complex and challenging patients [6].

In summary, the HeRO score can be used as a monitoring tool in very sick NICU patients at high risk for sepsis. However, in cases where patients have a history of frequent spikes unrelated to sepsis, establishing a stable baseline and considering clinical signs, laboratory findings, and biomarker testing can help clinicians better interpret the HeRO score and make informed decisions about patient care, including the use of antibiotics.

The passage you provided discusses the possible mechanisms underlying the abnormal Heart Rate Characteristics (HRC) observed in newborn infants, which resemble fetal distress. While the exact cause of this abnormality is not known, several factors are suggested, including abnormalities in autonomic activity, circulating cytokines, or deprivation of cellular substrates [7].

Similar patterns of reduced variability and transient decelerations seen in distressed fetal sheep can be induced by hypoxia or acidosis and prevented by blocking the parasympathetic nervous system with atropine. In sepsis, the presence of circulating cytokines, which interfere with signal transduction, may contribute to the abnormal HRC observed before the clinical diagnosis of neonatal sepsis.

The abnormal HRC observed in newborn infants with reduced variability and transient decelerations differs from the findings in critically ill children and adults with sepsis and systemic inflammatory response syndrome (SIRS), where the primary finding is reduced heart rate variability (HRV). Current theories of pathogenesis propose uncoupling of the autonomic and cardiovascular systems, while a cellular mechanism involving impaired intracellular signal transduction in sinus node cells has also been suggested. This mechanism could contribute to both reduced variability and transient decelerations [8].

Studies on Guinea pig heart cells have shown that even mild substrate depletion can lead to the opening of ATP-sensitive K channels, resulting in membrane hyperpolarization and suppression of spontaneous depolarization. Similar episodes of substrate depletion in pacemaker cells of the sino-atrial (SA) node could potentially cause hyperpolarization and reduced firing rates, contributing to the observed transient decelerations in the HRC [9].

In summary, the mechanisms underlying the abnormal HRC observed in newborn infants are not fully understood. However, possible factors include abnormalities in autonomic activity, circulating cytokines, and deprivation of cellular substrates. Further research is needed to better understand the specific mechanisms and their implications for neonatal health.

The passage you provided discusses the justification for using demographic features in predictive models for Heart Rate Characteristics (HRC) and highlights the changes observed in HRC postnatally, particularly in premature infants. The increase in standard deviation (SD) and sample asymmetry suggests an increasing responsiveness of autonomic control of heart rate after birth. The increase in sample asymmetry indicates a higher proportion of decelerations compared to accelerations, which is consistent with increasing vagal activity.

While quantitative analysis of heart rate variability (HRV) has been extensively studied in adults with heart disease and is associated with poorer prognosis, its clinical use is not widespread due to the availability of more conventional means to identify high-risk patients and the lack of clear interventions. On the other hand, qualitative analysis of fetal heart rate characteristics is widely used clinically, although its clinical utility is not consistently demonstrated [10].

The passage suggests that quantitative analysis of neonatal HRC could be a valuable monitoring tool. It would provide continuous and noninvasive monitoring without requiring additional contacts with the infant. The association between HRC and sepsis or sepsis-like illness, which are major causes of morbidity and mortality, indicates its potential clinical relevance. The intervention involved in HRC monitoring would primarily require timely assessment and closer observation by healthcare personnel, which is cost-effective. Therefore, HRC monitoring could be an effective and continuous assessment strategy for high-risk infants in the neonatal intensive care unit (NICU).

In summary, the passage emphasizes the potential of quantitative analysis of neonatal HRC as a continuous monitoring strategy in the NICU. It highlights the association between HRC and sepsis, suggesting that HRC monitoring could be a valuable tool for timely assessment and closer observation of high-risk infants, contributing to improved clinical outcomes without invasive interventions.

5 Conclusion

This study provides a descriptive overview of the characteristics of neonatal admissions to the Marrakech University Hospital during a ten-month period from September 2020 to June 2021. The findings show that respiratory distress syndrome, hyperbilirubinemia, and neonatal sepsis were the most common diagnoses. There is a need for further studies to investigate the risk factors, treatment modalities, and long-term outcomes of neonatal admissions in this region. The results of this study could serve as a reference for healthcare professionals and policymakers in improving the care of neonates in Marrakech University Hospital.

The HERO score is a useful tool for predicting the risk of infection in newborns and identifying those who may require closer monitoring or prophylactic treatment. Implementing this approach can help reduce the duration of TBA, decrease the length of hospital stay, and reduce the need for prolonged use of a respirator, which can improve the overall management of newborns and reduce morbidity and mortality. It’s important to continue to monitor and assess the effectiveness of this approach to improve the quality of care for neonatal patients in Morocco.