OBJECTIVE: To evaluate the effect of implementing automated oxygen control as routine care in maintaining oxygen saturation (SpO2) within target range in preterm infants. METHODS: Infants <30 weeks gestation in Leiden University Medical Centre before and after the implementation of automated oxygen control were compared. The percentage of time spent with SpO2 within and outside the target range (90-95%) was calculated. SpO2 values were collected every minute and included for analysis when infants received extra oxygen. RESULTS: In a period of 9 months, 42 preterm infants (21 manual, 21 automated) were studied. In the automated period, the median (IQR) time spent with SpO2 within target range increased (manual vs automated: 48.4 (41.5-56.4)% vs 61.9 (48.5-72.3)%; p<0.01) and time SpO2 >95% decreased (41.9 (30.6-49.4)% vs 19.3 (11.5-24.5)%; p<0.001). The time SpO2<90% increased (8.6 (7.2-11.7)% vs 15.1 (14.0-21.1)%; p<0.0001), while SpO2<80% was similar (1.1 (0.4-1.7)% vs 0.9 (0.5-2.1)%; ns). CONCLUSIONS: During oxygen therapy, preterm infants spent more time within the SpO2 target range after implementation of automated oxygen control, with a significant reduction in hyperoxaemia, but not hypoxaemia.
- MeSH
- Intubation, Intratracheal MeSH
- Intensive Care Units, Neonatal MeSH
- Oxygen administration & dosage blood MeSH
- Humans MeSH
- Monitoring, Physiologic * MeSH
- Noninvasive Ventilation MeSH
- Infant, Premature MeSH
- Infant, Newborn MeSH
- Oxygen Inhalation Therapy MeSH
- Oximetry * MeSH
- Prospective Studies MeSH
- Check Tag
- Humans MeSH
- Infant, Newborn MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Observational Study MeSH
Manual titration of inspired oxygen necessary to adequately respond to respiratory fluctuations of the neonate is a challenging task. Furthermore exposure to high and low levels of oxygen saturations are associated with significant morbidity and mortality. Ventilators that automatically control inspired oxygen based on pulse oximeter signals are becoming available, and seem to be safe and effective when compared to manual control. However the potential to overshoot in response to a hypoxemic episode, thus causing excess hyperoxemia, has not been carefully studied. We evaluated the response of one automated FiO2-SpO2control system to 9,486 desaturations in 21 infants over 113 days. We found that the sustained response to desaturations resulted primarily in achievement of normoxemia with balance between high and low saturations. We concluded that this closed loop control system was adequately damped. We suggest that this kind of analysis might be helpful is refining control algorithms.
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 ).
- 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
The introduction and adoption of new technology in medicine is a continuous ever present process but it is often not studied. Insights gained from documenting such experiences can not only guide local practices but also provide valuable quality benchmarks. Automated control of FiO2 based on continuous SpO2 (A-FiO2) not only reduces the challenging task of manual oxygen titration, but also has the potential to greatly improve the morbidity and mortality of extremely preterm infants. First approved for use in Europe in 2012, it is now available on most infant ventilators outside the USA. Poland was the first region in Europe to implement its clinical use. We report experience from 619 infants from 12 centers recorded in a web-based registry established in 2013 to document its use. We found the A-FiO2 was primarily used in the first week of life in intubated infants. However it is also successfully applied in both noninvasively supported infants and in those who were difficult to wean from oxygen and who exhibited frequent desaturations. We also found the SpO2 target range and alarm setting are not different from normal manual titration, although wider settings are also used and promise some benefit. Finally we report our plan to gather data from a national data base and detailed surveys. The surveys will document subjective aspects of this experience from a core group of centers. Details of the surveys are included and cover: experience with training and acceptance, changes in practice associated with the years of experience and barriers to broader use.
- MeSH
- Intensive Care Units, Neonatal * MeSH
- Humans MeSH
- Ventilators, Mechanical * MeSH
- Monitoring, Physiologic * MeSH
- Infant, Premature MeSH
- Infant, Newborn MeSH
- Oxygen Inhalation Therapy * methods instrumentation MeSH
- Oximetry * methods instrumentation MeSH
- Retrospective Studies MeSH
- Respiratory Distress Syndrome, Newborn * therapy MeSH
- Continuous Positive Airway Pressure methods instrumentation MeSH
- Respiration, Artificial * methods MeSH
- Positive-Pressure Respiration methods instrumentation MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Infant, Newborn MeSH
- Female MeSH
- Geographicals
- Poland 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.
- 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
OBJECTIVE: The performance of automated control of inspired oxygen (A-FiO2) has been confirmed in dozens of studies but reports of routine use are limited. Broadly adopted in Poland, our aim is to share that experience. METHODS: We used a prospectively planned observational study of the performance, general use patterns, unit practices, and problems with A-FiO2, based on a web registry of case reports, complemented by surveys of subjective impressions. RESULTS: In 2019, a total of 92 A-FiO2 systems were in routine use in 38 centers. Of the 38 centers, 20 had agreed in 2013 to participate in the project. In these centers, A-FiO2 was applied in infants of all weights, but some centers restricted its use to weaning from oxygen and unstable infants. A cohort had reported their experience with each use (5/20 centers, 593 cases). A quarter of those infants were managed with a lower target range and three-quarters with alarms looser than European guidelines for manual SpO2 control. The perceived primary advantages of A-FiO2 were as follows: keeping the readings in the target range, reducing exposure to SpO2 extremes, reducing risk from nurse distraction, reducing workload, and reducing alarm fatigue. Practices did evolve with experience, including implementing changes in the alarm strategy, indications for use, and target range. The potential for over-reliance on automation was cited as a risk. There were a few reports of limited effectiveness (moderate 12/593 and poor 2/593). CONCLUSIONS: Automated oxygen control is broadly perceived by users as an improvement in controlling SpO2 with infrequent problems.
- Publication type
- Journal Article MeSH
OBJECTIVE: To determine the efficacy and safety of automated adjustment of the fraction of inspired oxygen (FiO2) in maintaining arterial oxygen saturation (SpO2) within a higher (91%-95%) and a lower (89%-93%) target range in preterm infants. STUDY DESIGN: Eighty preterm infants (gestational age [median]: 26 weeks, age [median] 18 days) on noninvasive (n = 50) and invasive (n = 30) respiratory support with supplemental oxygen, were first randomized to one of the SpO2 target ranges and then treated with automated FiO2 (A-FiO2) and manual FiO2 (M-FiO2) oxygen control for 24 hours each, in random sequence. RESULTS: The percent time within the target range was higher during A-FiO2 compared with M-FiO2 control. This effect was more pronounced in the lower SpO2 target range (62 ± 17% vs 54 ± 16%, P < .001) than in the higher SpO2 target range (62 ± 17% vs 58 ± 15%, P < .001). The percent time spent below the target or in hypoxemia (SpO2 <80%) was consistently reduced during A-FiO2, independent of the target range. The time spent above the target range or at extreme hyperoxemia (SpO2 >98%) was only reduced during A-FiO2 when targeting the lower SpO2 range (89%-93%). These outcomes did not differ between infants on noninvasive and invasive respiratory support. Manual adjustments were significantly reduced during A-FiO2 control. CONCLUSIONS: A-FiO2 control improved SpO2 targeting across different SpO2 ranges and reduced hypoxemia in preterm infants on noninvasive and invasive respiratory support. TRIAL REGISTRATION: ISRCTN 56626482.
- MeSH
- Intensive Care Units, Neonatal MeSH
- Cross-Over Studies MeSH
- Oxygen blood therapeutic use MeSH
- Humans MeSH
- Infant, Premature MeSH
- Infant, Newborn MeSH
- Oximetry methods MeSH
- Respiration, Artificial methods MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Infant, Newborn MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Randomized Controlled Trial MeSH
- Geographicals
- Europe MeSH
- Canada MeSH
BACKGROUND: Large vessel carotid stenosis is a significant cause of ischaemic stroke. Indications for surgical revascularisation depend on the severity of the stenosis and clinical symptoms. However, mild symptoms such as TIA (Transient ischaemic attack), amaurosis fugax or minor stroke precede large strokes in only 15% of cases. AIM: The aim of this prospective study is to evaluate whether retinal perfusion is impacted in significant carotid stenosis. Automated retinal oximetry will be used to better assess perfusion in the post-stenotic basin. We presume the more stenotic the blood vessel, the more reduced the retinal perfusion is, resulting in adaptive changes such as greater arteriovenous saturation difference due to greater oxygen extraction. This could broaden the indication spectrum for revascularisation for carotid stenosis. METHODS: We plan to enroll yearly 50 patients with significant carotid stenosis and cross-examine them with retinal oximetry. The study group will provide stenotic vessels and, non-stenotic vessels will form the control group. Patients with significant carotid stenosis will undergo an MRI (Magnetic Resonnance imaging) examination to determine the presence of asymptomatic recent ischaemic lesions in the stenotic basin, and the correlation to oximetry parameters. STATISTICS: The stenosis severity and retinal oximetry parameters will be compared for study and control groups with a threshold of 70%, respectively 80% and 90% stenosis. Results will be then reevaluated with emphasis on MRI findings in the carotid basin. CONCLUSION: This prospective case control study protocol will be used to launch a multicentre trial assessing the relationship between significant carotid stenosis and retinal perfusion measured with automated retinal oximetry. Despite these differences, the findings indicate the potential of retinal oximetry for noninvasive real-time measurements of oxyhaemoglobin saturation in central nervous system vessels. Following calibration upgrade and technological improvement, verification retinal oximetry may potentially be applied to critically ill and anaesthesia care patients. The study on combined scanning laser ophthalmoscope and retinal oximetry supports the feasibility of the technique for oximetry analysis in newly born babies. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT06085612.
- MeSH
- Middle Aged MeSH
- Humans MeSH
- Oximetry * methods MeSH
- Prospective Studies MeSH
- Retina diagnostic imaging physiopathology MeSH
- Retinal Vessels diagnostic imaging physiopathology MeSH
- Aged MeSH
- Carotid Stenosis * physiopathology surgery complications MeSH
- Case-Control Studies MeSH
- Check Tag
- Middle Aged MeSH
- Humans MeSH
- Male MeSH
- Aged MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Clinical Trial Protocol MeSH
OBJECTIVE: This randomised study in preterm infants on non-invasive respiratory support investigated the effectiveness of automated oxygen control (A-FiO2) in keeping the oxygen saturation (SpO2) within a target range (TR) during a 28-day period compared with manual titration (M-FiO2). DESIGN: A single-centre randomised control trial. SETTING: A level III neonatal intensive care unit. PATIENTS: Preterm infants (<28 weeks' gestation) on non-invasive respiratory support. INTERVENTIONS: A-FiO2 versus M-FiO2 control. METHODS: Main outcomes were the proportion of time spent and median area of episodes in the TR, hyperoxaemia, hypoxaemia and the trend over 28 days using a linear random intercept model. RESULTS: 23 preterm infants (median gestation 25.7 weeks; birth weight 820 g) were randomised. Compared with M-FiO2, the time spent within TR was higher in the A-FiO2 group (68.7% vs 48.0%, p<0.001). Infants in the A-FiO2 group spent less time in hyperoxaemia (13.8% vs 37.7%, p<0.001), but no difference was found in hypoxaemia. The time-based analyses showed that the A-FiO2 efficacy may differ over time, especially for hypoxaemia. Compared with the M-FiO2 group, the A-FiO2 group had a larger intercept but with an inversed slope for the daily median area below the TR (intercept 70.1 vs 36.3; estimate/day -0.70 vs 0.69, p<0.001). CONCLUSION: A-FiO2 control was superior to manual control in keeping preterm infants on non-invasive respiratory support in a prespecified TR over a period of 28 days. This improvement may come at the expense of increased time below the TR in the first days after initiating A-FiO2 control. TRIAL REGISTRATION NUMBER: NTR6731.
- MeSH
- Hypoxia prevention & control MeSH
- Cross-Over Studies MeSH
- Infant MeSH
- Oxygen * MeSH
- Humans MeSH
- Infant, Premature * MeSH
- Infant, Newborn MeSH
- Birth Weight MeSH
- Check Tag
- Infant MeSH
- Humans MeSH
- Infant, Newborn MeSH
- Publication type
- Journal Article MeSH
- Randomized Controlled Trial MeSH
OBJECTIVE: This study aims to evaluate the performance of the fabian-Predictive-Intelligent-Control-of-Oxygenation (PRICO) system for automated control of the fraction of inspired oxygen (FiO2). DESIGN: Multicentre randomised cross-over study. SETTING: Five neonatal intensive care units experienced with automated control of FiO2 and the fabian ventilator. PATIENTS: 39 infants: median gestational age of 27 weeks (IQR: 26-30), postnatal age 7 days (IQR: 2-17), weight 1120 g (IQR: 915-1588), FiO2 0.32 (IQR: 0.22-0.43) receiving both non-invasive (27) and invasive (12) respiratory support. INTERVENTION: Randomised sequential 24-hour periods of automated and manual FiO2 control. MAIN OUTCOME MEASURES: Proportion (%) of time in normoxaemia (90%-95% with FiO2>0.21 and 90%-100% when FiO2=0.21) was the primary endpoint. Secondary endpoints were severe hypoxaemia (<80%) and severe hyperoxaemia (>98% with FiO2>0.21) and prevalence of episodes ≥60 s at these two SpO2 extremes. RESULTS: During automated control, subjects spent more time in normoxaemia (74%±22% vs 51%±22%, p<0.001) with less time above and below (<90% (9%±8% vs 12%±11%, p<0.001) and >95% with FiO2>0.21 (16%±19% vs 35%±24%) p<0.001). They spent less time in severe hyperoxaemia (1% (0%-3.5%) vs 5% (1%-10%), p<0.001) but exposure to severe hypoxaemia was low in both arms and not different. The differences in prolonged episodes of SpO2 were consistent with the times at extremes. CONCLUSIONS: This study demonstrates the ability of the PRICO automated oxygen control algorithm to improve the maintenance of SpO2 in normoxaemia and to avoid hyperoxaemia without increasing hypoxaemia.
- MeSH
- Hyperoxia prevention & control MeSH
- Hypoxia MeSH
- Intensive Care Units, Neonatal * MeSH
- Cross-Over Studies * MeSH
- Oxygen blood administration & dosage MeSH
- Humans MeSH
- Infant, Premature MeSH
- Infant, Newborn MeSH
- Oxygen Inhalation Therapy methods adverse effects instrumentation MeSH
- Oximetry methods MeSH
- Oxygen Saturation * MeSH
- Respiration, Artificial adverse effects MeSH
- Check Tag
- Humans MeSH
- Male MeSH
- Infant, Newborn MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
- Multicenter Study MeSH
- Pragmatic Clinical Trial MeSH
- Randomized Controlled Trial MeSH
