Dr. Gari D. Clifford, University Lecturer & Associate Director,

1. Current issues in healthcare2. Neonatal apneaCentre for Doctoral Training in Healthcare Innovation Dr. Gari D. Clifford, University Lecturer & Associate Director, Centre for Doctoral Training in Healthcare Innovation, Institute of Biomedical Engineering, University of Oxford

2. Current ICU Monitoring Systems Single & independent signal processing ECG (several leads), ABP, PAP, PLETH, RESP, etc.... Alarms issued when values cross “normal” thresholds Color-coded (RED, YELLOW, GREEN) alarms indicate case severity Cannot robustly distinguish between alarms caused by Physiologic changes and Noise, artifacts, data loss, monitor algorithm errors

3. The Problem High ICU False Alarm (FA) Rates: Broad disruption of care, impacting both patients & clinical staff. Alarms can produce noises > 80 dB: Patient sleep deprivation Stress for both patients and staff FA rates can be as high as 86%(Lawless, 1994): Desensitization of the clinical attending staff Delayed response times and confusion Ignored or missed critical alarms

4. Phenomenology of apnea Often accompanied by: Bradycardia (a heart rate less than 100 beats per minute in neonates and 50 beats per minute in adults), Cyanosis, or pallor (due to oxygen desaturation). Decrease in peripheral blood flow EEG changes suggesting CNS depression if apnea is severe Increase in venous pressure Decrease in muscle tone

5. Biggest problem alarm in ICU Most common life-threatening alarm in the ICU is apnea (breathing stops) Monitor recording no respiratory waveform and concluding that an apnea (cessation of inspiratory gas flow for 20 seconds)

6. Current situation To accurately detect episodes of apnea, bradycardia, and desaturation leading to hypoxia, or ‘spells’, human oversight is required to piece together the sequence of events, which are recorded on separate monitors that do not exchange information. Even then, many spells can be missed due to sensor artifact. Oxygen saturation & respiratory signals known to be extremely noisy Masks many true alarms and leads to many false alarms. The cost of missing or delaying reaction to apneas can be as severe as multi-organ damage and can lead to prolonged patient stays and poorer outcomes.

7. Apnea-associated clinical problems Respiratory Distress Syndrome Pulmonary mechanical problems such as Airleak, or Atelectasis Infectious causes such as Sepsis, Meningitis, or Pneumonia Intracranial Hemorrhage Seizures Anemia Gastroesophageal Reflux Necrotizing Enterocolitis Patent Ductus Arteriosus Hemorrhagic Shock Metabolic disturbances such as Hypoglycemia, Acidosis, Hyponatremia, Hypocalcemia Inappropriate Thermal Environment - Hyperthermia

8. What can we do to improve this? Improve apnea detector sensitivity (fewer false alarms) Improve apnea detector positive predictivity (fewer missed true alarms) Detect apneas before desaturation

9. References Nicu Web:http://depts.washington.edu/nicuweb/NICU-WEB/apnea.stm Aboukhalil, A., Nielsen, L., Saeed, M., Mark, R.G., Clifford, G.D., Reducing False Alarm Rates for Critical Arrhythmias using the Arterial Blood Pressure Waveform, Journal of Biomedical Informatics, Special Issue on Computerized Decision Support for Critical and Emergency Care, Volume 41, Issue 3, June 2008, pp 442-451, http://www.mit.edu/%7Egari/papers/fasup1.pdf Richard J. Martin, and Christopher G. Wilson What to do about apnea of prematurity?J Appl Physiol 107: 1015-1016, 2009. http://jap.physiology.org/cgi/content/full/107/4/1015

10. Biggest problem alarm in ICU Most common life-threatening alarm in the ICU is apnea (breathing stops) Monitor recording no respiratory waveform and concluding that an apnea (cessation of inspiratory gas flow for 20 seconds)