OBJECTIVE: Changes in oximeter averaging times have been noted to affect alarm settings. Automated algorithms (A-FiO2) assess FiO2 faster than oximeter averaging, potentially impacting their effectiveness. METHODS: In a single NICU routinely using 15 fabian-PRICO A-FiO2 systems, neonates were randomly exposed to SpO2 averaging time settings switched every 12 h among short (2-4 s), medium (10 s), and long (16 s) oximeter averaging times for the entire duration of their A-FiO2 exposure. Primary endpoints were the percent time in the set SpO2 target range (dependent on PMA), SpO2 < 80%, and SpO2 > 98%, excluding FiO2 = 0.21. RESULTS: Ten VLBW neonates were enrolled over 11 months. At entry, they were 17 days old (IQR: 14-19), with an adjusted gestational age of 29 weeks (IQR: 27-30). The study included data from 272 days of A-FiO2 control (34% short, 32% medium, and 34% long). Respiratory support was predominantly non-invasive (53% NCPAP, 40% HFNC, and 6% NIPPV). The aggregate SpO2 exposure levels were 67% (IQR: 55-82) in the target range, 5.4% (IQR: 2.0-10) with SpO2 < 80%, and 1.2% (IQR: 0.4-3.1) with SpO2 > 98%. There were no differences in the target range time between the SpO2 averaging time settings. There were differences at the SpO2 extremes (p ≤ 0.001). The medium and long averaging were both lower than the short, with the difference larger than predicted. Multivariate analysis revealed that these findings were independent of subject, ventilation mode, target range, and overall stability. CONCLUSIONS: This A-FiO2 algorithm is effective regardless of the SpO2 averaging time setting. There is an advantage to the longer settings, which suggest an interaction with the controller.

• Keywords
• SpO2 targeting, automated oxygen control, neonatal, oxygen control, pulse oximetry,
• Publication type
• Journal Article MeSH

OBJECTIVE: Neonatal exposure to episodic hypoxemia and hyperoxemia is highly relevant to outcomes. Our goal was to investigate the differences in the frequency and duration of extreme low and high SpO2 episodes between automated and manual inspired oxygen control. DESIGN: Post-hoc analysis of a cohort from prospective randomized cross-over studies. SETTING: Seven tertiary care neonatal intensive care units. PATIENTS: Fifty-eight very preterm neonates (32 or less weeks PMA) receiving respiratory support and supplemental oxygen participating in an automated versus manual oxygen control cross-over trial. MAIN MEASURES: Extreme hypoxemia was defined as a SpO2 < 80%, extreme hyperoxemia as a SpO2 > 98%. Episode duration was categorized as < 5 seconds, between 5 to < 30 seconds, 30 to < 60 seconds, 60 to < 120 seconds, and 120 seconds or longer. RESULTS: The infants were of a median postmenstrual age of 29 (28-31) weeks, receiving a median FiO2 of 0.28 (0.25-0.32) with mostly receiving non-invasive respiratory support (83%). While most of the episodes were less than 30 seconds, longer episodes had a marked effect on total time exposure to extremes. The time differences in each of the three longest durations episodes (30, 60, and 120 seconds) were significantly less during automated than during manual control (p < 0.001). Nearly two-third of the reduction of total time spent at the extremes between automated and manual control (3.8 to 2.1% for < 80% SpO2 and 3.0 to 1.6% for > 98% SpO2) was seen in the episodes of at least 60 seconds. CONCLUSIONS: This study shows that the majority of episodes preterm infants spent in SpO2 extremes are of short duration regardless of manual or automated control. However, the infrequent longer episodes not only contribute the most to the total exposure, but also their reduction in frequency to the improvement associated with automated control.

• Keywords
• Hyperoxemia episodes, Hypoxemic episodes, Neonatology, Oxygen saturation,
• MeSH
• Hypoxia etiology   therapy   MeSH
• Infant MeSH
• Oxygen * MeSH
• Humans MeSH
• Infant, Premature * MeSH
• Infant, Newborn MeSH
• Oximetry MeSH
• Prospective Studies MeSH
• Retrospective Studies MeSH
• Check Tag
• Infant MeSH
• Humans MeSH
• Infant, Newborn MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Oxygen * MeSH

BACKGROUND: Changes in oxygen saturation (SpO2) exposure have been shown to have a marked impact on neonatal outcomes and therefore careful titration of inspired oxygen is essential. In routine use, however, the frequency of SpO2 alarms not requiring intervention results in alarm fatigue and its corresponding risk. SpO2 control systems that automate oxygen adjustments (Auto-FiO2) have been shown to be safe and effective. We speculated that when using Auto-FiO2, alarm settings could be refined to reduce unnecessary alarms, without compromising safety. METHODS: An unblinded randomized crossover study was conducted in a single NICU among infants routinely managed with Auto-FiO2. During the first 6 days of respiratory support a tight and a loose alarm strategy were switched each 24 h. A balanced block randomization was used. The tight strategy set the alarms at the prescribed SpO2 target range, with a 30-s delay. The loose strategy set the alarms 2 wider, with a 90-s delay. The effectiveness outcome was the frequency of SpO2 alarms, and the safety outcomes were time at SpO2 extremes (< 80, > 98%). We hypothesized that the loose strategy would result in a marked decrease in the frequency of SpO2 alarms, and no increases at SpO2 extremes with 20 subjects. Within subject differences between alarm strategies for the primary outcomes were evaluated with Wilcoxon signed-rank test. RESULTS: During a 13-month period 26 neonates were randomized. The analysis included 21 subjects with 49 days of both tight and loose intervention. The loose alarm strategy resulted in a reduction in the median rate of SpO2 alarms from 5.2 to 1.6 per hour (p < 0.001, 95%-CI difference 1.6-3.7). The incidence of hypoxemia and hyperoxemia were very low (less than 0.1%-time) with no difference associated with the alarm strategy (95%-CI difference less than 0.0-0.2%). CONCLUSIONS: In this group of infants we found a marked advantage of the looser alarm strategy. We conclude that the paradigms of alarm strategies used for manual titration of oxygen need to be reconsidered when using Auto-FiO2. We speculate that with optimal settings false positive SpO2 alarms can be minimized, with better vigilance of clinically relevant alarms. TRIAL REGISTRATION: Retrospectively registered 15 May 2018 at ISRCTN ( 49239883 ).

• Keywords
• Alarm fatigue, Automated oxygen control, Oxygen saturation,
• MeSH
• Automation MeSH
• Hypoxia prevention & control   MeSH
• Intensive Care Units, Neonatal MeSH
• Clinical Alarms * MeSH
• Cross-Over Studies MeSH
• Humans MeSH
• Monitoring, Physiologic MeSH
• Hospitals, Public MeSH
• Infant, Premature * MeSH
• Infant, Newborn MeSH
• Oxygen Inhalation Therapy methods   MeSH
• Oximetry MeSH
• Critical Care methods   MeSH
• Prognosis MeSH
• Oxygen Consumption physiology   MeSH
• Respiration, Artificial methods   MeSH
• Treatment Outcome MeSH
• Check Tag
• Humans MeSH
• Male MeSH
• Infant, Newborn MeSH
• Female MeSH
• Publication type
• Journal Article MeSH
• Randomized Controlled Trial MeSH
• Geographicals
• Poland MeSH