HIRA: heart rate interval based rapid alert score to characterize autonomic dysfunction among patients with sepsis-related acute respiratory failure (ARF).
Preethi KrishnanMilad G RadPalak AggarwalCurtis MarshallPhilip YangSivasubramanium V BhavaniAndre L HolderAnnette EsperRishikesan KamaleswaranPublished in: Physiological measurement (2023)
To examine whether Heart rate Interval based Rapid Alert (HIRA) score derived from a combination model of Heart rate variability (HRV) and Modified Early Warning Score (MEWS) is a surrogate for the detection of Acute Respiratory Failure (ARF) in critically ill sepsis patients.

Approach : Retrospective HRV analysis of sepsis patients admitted to Emory Healthcare Intensive Care Unit (ICU) was performed between sepsis-related ARF and sepsis controls without ARF. HRV measures such as time domain, frequency domain, and nonlinear measures were analyzed up to 24 hours after patient admission, 1 hour before the onset of ARF, and a random event time in the sepsis controls. Statistical significance was computed by the Wilcoxon Rank Sum test. Machine learning algorithms such as eXtreme Gradient Boosting (XGBOOST) and logistic regression were developed to validate the HIRA score model. The performance of HIRA and early warning score models were evaluated using the Area Under the Receiver Operating Characteristic (AUROC). 

Main Results: A total of 89 (ICU) patients with sepsis were included in this retrospective cohort study, of whom 31 (34%) developed sepsis-related ARF and 58 (65%) were sepsis controls without ARF. Time-domain HRV for Electrocardiogram (ECG) Beat-to-Beat RR intervals strongly distinguished ARF patients from controls. HRV measures for nonlinear and frequency domains were significantly altered (p<0.05) among ARF compared to controls. The HIRA score AUC: 0.93; 95% Confidence Interval (CI): 0.88-0.98) showed a higher predictive ability to detect ARF when compared to MEWS (AUC: 0.71; 95% CI: 0.50 - 0.90). 

Significance: HRV was significantly impaired across patients who developed ARF when compared to controls. The HIRA score uses non-invasively derived HRV and may be used to inform diagnostic and therapeutic decisions regarding the severity of sepsis and earlier identification of the need for mechanical ventilation. 
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Keyphrases
- intensive care unit
- heart rate
- mechanical ventilation
- respiratory failure
- heart rate variability
- septic shock
- acute kidney injury
- blood pressure
- machine learning
- healthcare
- end stage renal disease
- extracorporeal membrane oxygenation
- acute respiratory distress syndrome
- emergency department
- chronic kidney disease
- ejection fraction
- liver failure
- case report
- cross sectional
- oxidative stress
- loop mediated isothermal amplification
- magnetic resonance imaging
- social media
- peritoneal dialysis
- hepatitis b virus
- climate change
- artificial intelligence
- deep learning
- aortic dissection