A randomised controlled trial of an automated oxygen delivery algorithm for preterm neonates receiving supplemental oxygen without mechanical ventilation

Apnoea-triggered increase in fraction of inspired oxygen in preterm infants: a randomised cross-over study

OBJECTIVES

To investigate the impact of a pre-emptive apnoea triggered oxygen response on oxygen saturation (SpO2) targeting following central apnoea in preterm infants.

DESIGN

Interventional crossover study of a 12-hour period of automated oxygen control with an apnoea response (AR) module, nested within a crossover study of a 24-hour period of automated oxygen control compared with aggregated data from two flanking 12-hour periods of manual control.

SETTING

Neonatal intensive care unit PATIENTS: Preterm infants receiving non-invasive respiratory support and supplemental oxygen; median (IQR) birth gestation 27 (26-28) weeks, postnatal age 17 (12-23) days.

INTERVENTION

Automated oxygen titration with an automated control algorithm modified to include an AR module. Alterations to inspired oxygen concentration (FiO2) were actuated by a motorised blender. Desired SpO2 range was 90-94%. Apnoea detection was by capsule pneumography.

MAIN OUTCOME MEASURES

Duration, magnitude and area under the curve (AUC) of SpO2 deviations following apnoea; frequency and duration of apnoeic events. Comparisons between periods of manual, automated and automated control with AR module.

RESULTS

In 60 studies in 35 infants, inclusion of the AR module significantly reduced AUC for SpO2 deviations below baseline compared with both automated and manual control (manual: 87.1%±107.6% s, automated: 84.6%±102.8% s, AR module: 79.4%±102.7% s). However, there was a coincident increase in SpO2 overshoot (AUC (SpO2>SpO2(onset)); manual: 44.3±99.9% s, automated: 54.7%±103.4% s, AR module: 65.7%±126.2% s).

CONCLUSION

Automated control with a pre-emptive apnoea-triggered FiO2 boost resulted in a modest reduction in post-apnoea hypoxaemia, but was followed by a greater SpO2 overshoot.

TRIAL REGISTRATION NUMBER

ACTRN12616000300471.

Automated oxygen delivery for preterm infants with respiratory dysfunction

BACKGROUND

Many preterm infants require respiratory support to maintain an optimal level of oxygenation, as oxygen levels both below and above the optimal range are associated with adverse outcomes. Optimal titration of oxygen therapy for these infants presents a major challenge, especially in neonatal intensive care units (NICUs) with suboptimal staffing. Devices that offer automated oxygen delivery during respiratory support of neonates have been developed since the 1970s, and individual trials have evaluated their effectiveness.

OBJECTIVES

To assess the benefits and harms of automated oxygen delivery systems, embedded within a ventilator or oxygen delivery device, for preterm infants with respiratory dysfunction who require respiratory support or supplemental oxygen therapy.

SEARCH METHODS

We searched CENTRAL, MEDLINE, CINAHL, and clinical trials databases without language or publication date restrictions on 23 January 2023. We also checked the reference lists of retrieved articles for other potentially eligible trials.

SELECTION CRITERIA

We included randomised controlled trials and randomised cross-over trials that compared automated oxygen delivery versus manual oxygen delivery, or that compared different automated oxygen delivery systems head-to-head, in preterm infants (born before 37 weeks' gestation).

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our main outcomes were time (%) in desired oxygen saturation (SpO2) range, all-cause in-hospital mortality by 36 weeks' postmenstrual age, severe retinopathy of prematurity (ROP), and neurodevelopmental outcomes at approximately two years' corrected age. We expressed our results using mean difference (MD), standardised mean difference (SMD), and risk ratio (RR) with 95% confidence intervals (CIs). We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included 18 studies (27 reports, 457 infants), of which 13 (339 infants) contributed data to meta-analyses. We identified 13 ongoing studies. We evaluated three comparisons: automated oxygen delivery versus routine manual oxygen delivery (16 studies), automated oxygen delivery versus enhanced manual oxygen delivery with increased staffing (three studies), and one automated system versus another (two studies). Most studies were at low risk of bias for blinding of personnel and outcome assessment, incomplete outcome data, and selective outcome reporting; and half of studies were at low risk of bias for random sequence generation and allocation concealment. However, most were at high risk of bias in an important domain specific to cross-over trials, as only two of 16 cross-over trials provided separate outcome data for each period of the intervention (before and after cross-over). Automated oxygen delivery versus routine manual oxygen delivery Automated delivery compared with routine manual oxygen delivery probably increases time (%) in the desired SpO2 range (MD 13.54%, 95% CI 11.69 to 15.39; I2 = 80%; 11 studies, 284 infants; moderate-certainty evidence). No studies assessed in-hospital mortality. Automated oxygen delivery compared to routine manual oxygen delivery may have little or no effect on risk of severe ROP (RR 0.24, 95% CI 0.03 to 1.94; 1 study, 39 infants; low-certainty evidence). No studies assessed neurodevelopmental outcomes. Automated oxygen delivery versus enhanced manual oxygen delivery There may be no clear difference in time (%) in the desired SpO2 range between infants who receive automated oxygen delivery and infants who receive manual oxygen delivery (MD 7.28%, 95% CI -1.63 to 16.19; I2 = 0%; 2 studies, 19 infants; low-certainty evidence). No studies assessed in-hospital mortality, severe ROP, or neurodevelopmental outcomes. Revised closed-loop automatic control algorithm (CLACfast) versus original closed-loop automatic control algorithm (CLACslow) CLACfast allowed up to 120 automated adjustments per hour, whereas CLACslow allowed up to 20 automated adjustments per hour. CLACfast may result in little or no difference in time (%) in the desired SpO2 range compared to CLACslow (MD 3.00%, 95% CI -3.99 to 9.99; 1 study, 19 infants; low-certainty evidence). No studies assessed in-hospital mortality, severe ROP, or neurodevelopmental outcomes. OxyGenie compared to CLiO2 Data from a single small study were presented as medians and interquartile ranges and were not suitable for meta-analysis.

AUTHORS' CONCLUSIONS

Automated oxygen delivery compared to routine manual oxygen delivery probably increases time in desired SpO2 ranges in preterm infants on respiratory support. However, it is unclear whether this translates into important clinical benefits. The evidence on clinical outcomes such as severe retinopathy of prematurity are of low certainty, with little or no differences between groups. There is insufficient evidence to reach any firm conclusions on the effectiveness of automated oxygen delivery compared to enhanced manual oxygen delivery or CLACfast compared to CLACslow. Future studies should include important short- and long-term clinical outcomes such as mortality, severe ROP, bronchopulmonary dysplasia/chronic lung disease, intraventricular haemorrhage, periventricular leukomalacia, patent ductus arteriosus, necrotising enterocolitis, and long-term neurodevelopmental outcomes. The ideal study design for this evaluation is a parallel-group randomised controlled trial. Studies should clearly describe staffing levels, especially in the manual arm, to enable an assessment of reproducibility according to resources in various settings. The data of the 13 ongoing studies, when made available, may change our conclusions, including the implications for practice and research.

The impact after 20 years of an early detection program for severe retinopathy of prematurity in a Latin American city

Purpose

To evaluate the effects of long-standing early detection program in the incidence and trends of severe retinopathy of prematurity (ROP) in Cali, Colombia.

Methods

This was a retrospective cohort study of infants included in an ROP prevention, early detection, and prompt treatment program, from January 01, 2002, to December 31, 2021 (20 years). Infants with gestational age (GA) <37 weeks or birth weight (BW) <2000 g and those with known ROP risk factors were screened. The incidence of severe ROP was calculated, and the average annual percent change (AAPC) was estimated through a joinpoint model.

Results

16,580 infants were screened, with an average GA and BW of 31.4 ± 2.8 weeks and 1526.5 ± 56.7 g, respectively. The incidence of severe ROP was 2.69% (446 cases, 95% confidence interval [95%CI]: 2.45%; 2.95%), with an average annual decrease of - 14% (AAPC, 95%CI: -16.3%; -11.6%) from 13.6% in 2002 to 0.7% in 2021. In infants with GA <32 weeks, the incidence was 5.21%. A significant reduction in the risk of ROP was observed with increasing GA and BW (P < 0.05). Among the cases with severe ROP, 6.5% (29/446) had a GA ≥32 weeks with a maximum of 37 weeks; only 0.4% (2/446) of the detected infants had a BW >2000 g.

Conclusion

Awareness and screening as part of the early detection program to prevent ROP has shown a significant decline in the incidence of severe ROP over time. Screening infants with GA <32 weeks or BW <2000 g and preterm infants (<37 weeks) with risk factors may be a feasible decision for resource optimization.

Automatic oxygen control for reducing extremes of oxygen saturation: a randomised controlled trial

OBJECTIVE

The objective of this study was to evaluate the efficacy of the automatic oxygen control (A-Fio₂) in reducing the percentage of time spent in severe hypoxaemia (Spo₂ <80%) in preterm infants for the time period on invasive ventilation and/or nasal continuous positive airway pressure (NCPAP) delivered by AVEA ventilator.

DESIGN

A parallel arm randomised controlled trial.

SETTING

A level-III neonatal intensive care unit.

PATIENTS

Preterm infants (<33 weeks birth gestation) who received invasive ventilation or NCPAP in the first 72 hours of age.

INTERVENTIONS

A-Fio₂ vs manual (M-Fio₂) oxygen control.

OUTCOMES

The primary outcome of the study was percentage of time spent in severe hypoxaemia (Spo₂ <80%).

RESULTS

44 infants were randomised to either A-Fio₂ or M-Fio₂ arm and continued in the study for the period of respiratory support (invasive ventilation and/or NCPAP). The total number of study days in A-Fio2 and M-Fio₂ arm were 194 and 204 days, respectively. The percentage of time spent in Spo₂ <80% was significantly lower with A-Fio₂ compared with M-Fio₂ (median of 0.1% (IQR: 0.07-0.7) vs 0.6% (0.2-2); p=0.03). The number of prolonged episodes (>60 s) of Spo₂ <80% per day was also significantly lower in A-Fio₂ (0.3 (0.0-2) vs 2 (0.6-6); p=0.02).

CONCLUSION

A-Fio₂ was associated with statistically significant reduction in the percentage of time spent in severe hypoxaemia when compared with M-Fio₂ in preterm infants receiving respiratory support.

TRIAL REGISTRATION NUMBER

NCT04223258.

Closed–loop oxygen control improves oxygenation in pediatric patients under high–flow nasal oxygen—A randomized crossover study

Background

We assessed the effect of a closed–loop oxygen control system in pediatric patients receiving high–flow nasal oxygen therapy (HFNO).

Methods

A multicentre, single–blinded, randomized, and cross–over study. Patients aged between 1 month and 18 years of age receiving HFNO for acute hypoxemic respiratory failure (AHRF) were randomly assigned to start with a 2–h period of closed–loop oxygen control or a 2–h period of manual oxygen titrations, after which the patient switched to the alternative therapy. The endpoints were the percentage of time spent in predefined SpO2 ranges (primary), FiO2, SpO2/FiO2, and the number of manual adjustments.

Findings

We included 23 patients, aged a median of 18 (3–26) months. Patients spent more time in a predefined optimal SpO2 range when the closed–loop oxygen controller was activated compared to manual oxygen titrations [91⋅3% (IQR 78⋅4–95⋅1%) vs. 63⋅0% (IQR 44⋅4–70⋅7%)], mean difference [28⋅2% (95%–CI 20⋅6–37⋅8%); P &lt; 0.001]. Median FiO2 was lower [33⋅3% (IQR 26⋅6–44⋅6%) vs. 42⋅6% (IQR 33⋅6–49⋅9%); P = 0.07], but median SpO2/FiO2 was higher [289 (IQR 207–348) vs. 194 (IQR 98–317); P = 0.023] with closed–loop oxygen control. The median number of manual adjustments was lower with closed–loop oxygen control [0⋅0 (IQR 0⋅0–0⋅0) vs. 0⋅5 (IQR 0⋅0–1⋅0); P &lt; 0.001].

Conclusion

Closed-loop oxygen control improves oxygenation therapy in pediatric patients receiving HFNO for AHRF and potentially leads to more efficient oxygen use. It reduces the number of manual adjustments, which may translate into decreased workloads of healthcare providers.

Clinical trial registration

[www.ClinicalTrials.gov], identifier [NCT 05032365].

Technology in the delivery room supporting the neonatal healthcare provider's task

Very preterm infants are a unique and highly vulnerable group of patients that have a narrow physiological margin within which interventions are safe and effective. The increased understanding of the foetal to neonatal transition marks the intricacy of the rapid and major physiological changes that take place, making delivery room stabilisation and resuscitation an increasingly complex and sophisticated activity for caregivers to perform. While modern, automated technologies are progressively implemented in the neonatal intensive care unit (NICU) to enhance the caregivers in providing the right care for these patients, the technology in the delivery room still lags far behind. Diligent translation of well-known and promising technological solutions from the NICU to the delivery room will allow for better support of the caregivers in performing their tasks. In this review we will discuss the current technology used for stabilisation of preterm infants in the delivery room and how this could be optimised in order to further improve care and outcomes of preterm infants in the near future.

Clinical Evaluation of an Automatic Oxygen Control System for Premature Infants Receiving High-Flow Nasal Cannula for Respiratory Support: A Pilot Study

A pilot clinical study was conducted that compared the peripheral oxygen saturation (SpO2) targeting performance of an automatic oxygen control system with manual oxygen control, which is the standard of care for preterm and low birth weight infants on high-flow nasal cannula (HFNC). The new oxygen control device studied was used to automatically adjust the fraction of inspired oxygen (FiO2) according to a desired SpO2 target setpoint and measured feedback signals including the SpO2 and other signals. A crossover study was designed with several endpoints including the comparison of the percentage of time that the SpO2 was within the target range with the automatic oxygen control device versus manual oxygen control. Other metrics were also compared to assess the performance of the system including the number of bradycardia events. The pilot study included six patients that fit the inclusion criteria. The results showed that there were improvements in all of the measured outcomes considered including statistically significant improvements in the number of bradycardia events during the period when the automatic oxygen control device was used.

Automated control of oxygen titration in preterm infants on non-invasive respiratory support

OBJECTIVE

To evaluate the performance of a rapidly responsive adaptive algorithm (VDL1.1) for automated oxygen control in preterm infants with respiratory insufficiency.

DESIGN

Interventional cross-over study of a 24-hour period of automated oxygen control compared with aggregated data from two flanking periods of manual control (12 hours each).

SETTING

Neonatal intensive care unit.

PARTICIPANTS

Preterm infants receiving non-invasive respiratory support and supplemental oxygen; median birth gestation 27 weeks (IQR 26-28) and postnatal age 17 (12-23) days.

INTERVENTION

Automated oxygen titration with the VDL1.1 algorithm, with the incoming SpO₂ signal derived from a standard oximetry probe, and the computed inspired oxygen concentration (FiO₂) adjustments actuated by a motorised blender. The desired SpO₂ range was 90%-94%, with bedside clinicians able to make corrective manual FiO₂ adjustments at all times.

MAIN OUTCOME MEASURES

Target range (TR) time (SpO₂ 90%-94% or 90%-100% if in air), periods of SpO₂ deviation, number of manual FiO₂ adjustments and oxygen requirement were compared between automated and manual control periods.

RESULTS

In 60 cross-over studies in 35 infants, automated oxygen titration resulted in greater TR time (manual 58 (51-64)% vs automated 81 (72-85)%, p<0.001), less time at both extremes of oxygenation and considerably fewer prolonged hypoxaemic and hyperoxaemic episodes. The algorithm functioned effectively in every infant. Manual FiO₂ adjustments were infrequent during automated control (0.11 adjustments/hour), and oxygen requirements were similar (manual 28 (25-32)% and automated 26 (24-32)%, p=0.13).

CONCLUSION

The VDL1.1 algorithm was safe and effective in SpO₂ targeting in preterm infants on non-invasive respiratory support.

TRIAL REGISTRATION NUMBER

ACTRN12616000300471.

Automated Oxygen Delivery in Neonatal Intensive Care

Oxygen is the most common drug used in the neonatal intensive care. It has a narrow therapeutic range in preterm infants. Too high (hyperoxemia) or low oxygen (hypoxemia) is associated with adverse neonatal outcomes. It is not only prudent to maintain oxygen saturations in the target range, but also to avoid extremes of oxygen saturations. In routine practice when done manually by the staff, it is challenging to maintain oxygen saturations within the target range. Automatic control of oxygen delivery is now feasible and has shown to improve the time spent with in the target range of oxygen saturations. In addition, it also helps to avoid extremes of oxygen saturation. However, there are no studies that evaluated the clinical outcomes with automatic control of oxygen delivery. In this narrative review article, we aim to present the current evidence on automatic oxygen control and the future directions.

New Modes of Respiratory Support for the Premature Infant: Automated Control of Inspired Oxygen Concentration

Most extremely premature infants have respiratory instability that can manifest as frequent episodes of intermittent hypoxemia. Although caregivers target clinically recommended ranges of arterial oxygen saturation (oxygen saturation as measured by pulse oximetry [Spo₂]), consistent maintenance of these ranges is not always achieved. Excessive administration of supplemental oxygen combined with limited staff resources increases exposure to extreme Spo₂ levels. In this population, exposure to hyperoxemia and prolonged episodes of intermittent hypoxemia have been associated with damage to the eye and lung and impaired neurodevelopment. To improve Spo₂ targeting, various systems for automated control of inspired oxygen have been developed recently.

Predictive Intelligent Control of Oxygenation (PRICO) in preterm infants on high flow nasal cannula support: a randomised cross-over study

OBJECTIVE

To investigate the efficacy of automated control of inspired oxygen (FiO2) by Predictive Intelligent Control of Oxygenation (PRICO) on the Fabian ventilator in maintaining oxygen saturation (SpO2) in preterm infants on high flow nasal cannula (HFNC) support.

DESIGN

Single-centre randomised two-period crossover study.

SETTING

Tertiary neonatal intensive care unit.

PATIENTS

27 preterm infants (gestational age (GA) <30 weeks) on HFNC support with FiO2 >0.25.

INTERVENTION

A 24-hour period on automated FiO2-control with PRICO compared with a 24-hour period on routine manual control (RMC) to maintain a SpO2 level within target range of 88%-95% measured at 30 s intervals.

MAIN OUTCOME MEASURES

Primary outcome: time spent within target range (88%-95%).

SECONDARY OUTCOMES

time spent above and below target range, in severe hypoxia (SpO2 <80%) and hyperoxia (SpO2 >98%), mean SpO2 and FiO2 and manual FiO2 adjustments.

RESULTS

15 patients received PRICO-RMC and 12 RMC-PRICO. The mean time within the target range increased with PRICO: 10.8% (95% CI 7.6 to 13.9). There was a decrease in time below target range: 7.6% (95% CI 4.2 to 11.0), above target range: 3.1% (95% CI 2.9 to 6.2) and in severe hypoxia: 0.9% (95% CI 1.5 to 0.2). We found no difference in time spent in severe hyperoxia. Mean FiO2 was higher during PRICO: 0.019 (95% CI 0.006 to 0.030). With PRICO there was a reduction of manual adjustments: 9/24 hours (95% CI 6 to 12).

CONCLUSION

In preterm infants on HFNC support, automated FiO2-control by PRICO is superior to RMC in maintaining SpO2 within target range. Further validation studies with a higher sample frequency and different ventilation modes are needed.

Eligibility Criteria and Representativeness of Randomized Clinical Trials That Include Infants Born Extremely Premature: A Systematic Review

OBJECTIVE

To assess the eligibility criteria and trial characteristics among contemporary (2010-2019) randomized clinical trials (RCTs) that included infants born extremely preterm (<28 weeks of gestation) and to evaluate whether eligibility criteria result in underrepresentation of high-risk subgroups (eg, infants born at <24 weeks of gestation).

STUDY DESIGN

PubMed and Scopus were searched January 1, 2010, to December 31, 2019, with no language restrictions. RCTs with mean or median gestational ages at birth of <28 weeks of gestation were included. The study followed the PRISMA guidelines; outcomes were registered prospectively. Data extraction was performed independently by multiple observers. Study quality was evaluated using a modified Jadad scale.

RESULTS

Among RCTs (n = 201), 32 552 infants were included. Study participant characteristics, interventions, and outcomes were highly variable. A total of 1603 eligibility criteria were identified; rationales were provided for 18.8% (n = 301) of criteria. Fifty-five RCTs (27.4%) included infants <24 weeks of gestation; 454 (1.4%) infants were identified as <24 weeks of gestation.

CONCLUSIONS

The present study identifies sources of variability across RCTs that included infants born extremely preterm and reinforces the critical need for consistent and transparent policies governing eligibility criteria.

Automated versus manual oxygen control in preterm infants receiving respiratory support: a systematic review and meta-analysis

BACKGROUND

Ventilated preterm infants are exposed to deviations from the intended arterial oxygen saturation range. Therefore, an automated control system was developed to rapidly modulate the fraction of inspired oxygen. The aim of this review is to compare the efficacy and safety of automated versus manual oxygen delivery control.

METHODS

In December 2020, we systematically searched four electronic databases; PubMed, Cochrane Library, Scopus, and Web of Science for eligible randomized controlled trials. We extracted and pooled data as mean difference and 95% confidence interval in an inverse variance method using RevMan software.

RESULTS

Thirteen trials were included in this systematic review and meta-analysis, enrolling 343 preterm infants on respiratory support. Automated oxygen control increased the time spent within the target arterial oxygen saturation range of 85-96% (MD = 8.96; 95% CI [6.26, 11.67], p<.00001), and 90-95% (MD = 18.25; 95% CI [4.58, 31.65], p = .008). In addition, it reduced the time of hypoxia (<80%); (MD = -1.24; 95% CI [-2.05, -0.43], p = .003), (MD = -0.82; 95% CI [-1.23, -0.41], p<.0001) with predetermined ranges of 85-96% and 90-95%, respectively. Automated control system reduced as well the time of hyperoxia (>98%) (MD = -0.99; 95% CI [-1.74, -0.25], p = .009) at intended range of 90-95%, and number of manual inspired oxygen fraction adjustments (MD = -2.82; 95% CI [-4.56, -1.08], p = .002).

CONCLUSIONS

Automated oxygen delivery is rapid and effective in controlling infants' oxygen saturation. It can be used to reduce the load over the nurses, but not to substitute the clinical supervision. Further long-term trials of large-scale are required to evaluate the prolonged clinical outcomes.

Automated control of fraction of inspired oxygen: is it time for widespread adoption?

PURPOSE OF REVIEW

Over the past two decades, numerous algorithms for automated control of the fraction of inspired oxygen (FiO2) have been developed and incorporated into contemporary neonatal ventilators and high-flow devices in an attempt to optimize supplemental oxygen therapy in preterm infants. This review explores whether current evidence is sufficient to recommend widespread adoption of automated oxygen control in neonatal care.

RECENT FINDINGS

To date, 15 studies have compared automated versus manual control of FiO2 in preterm infants on respiratory support. This includes four new randomized cross-over trials published in the last 2 years. Available evidence consistently demonstrates a significant improvement in time spent within the target saturation range with automated FiO2 control. There are fewer episodes of severe hypoxemia and fewer manual FiO2 adjustments with automated oxygen control. Nursing workload may be reduced. However, no currently completed studies report on clinical outcomes, such as chronic lung disease or retinopathy of prematurity.

SUMMARY

Automated oxygen control appears to be a reasonable option for FiO2 titration in preterm infants on respiratory support, if resources are available, and might substantially reduce nursing workload. Further randomized clinical trials to explore its effects on clinical outcomes are required.

Automated oxygen control in preterm infants, how does it work and what to expect: a narrative review

BACKGROUND

Automated oxygen control systems are finding their way into contemporary ventilators for preterm infants, each with its own algorithm, strategy and effect.

OBJECTIVE

To provide guidance to clinicians seeking to comprehend automated oxygen control and possibly introduce this technology in their practice.

METHOD

A narrative review of the commercially available devices using different algorithms incorporating rule-based, proportional-integral-derivative and adaptive concepts are described and explained. An overview of how they work and, if available, the clinical effect is given.

RESULTS

All algorithms have shown a beneficial effect on the proportion of time that oxygen saturation is within target range, and a decrease in hyperoxia and severe hypoxia. Automated oxygen control may also reduce the workload for bedside staff. There is concern that such devices could mask clinical deterioration, however this has not been reported to date.

CONCLUSIONS

So far, trials involving different algorithms are heterogenous in design and no head-to-head comparisons have been made, making it difficult to differentiate which algorithm is most effective and what clinicians can expect from algorithms under certain conditions.

A randomised crossover trial of closed loop automated oxygen control in preterm, ventilated infants

AIM

To determine whether closed loop automated oxygen control resulted in a reduction in the duration and severity of desaturation episodes and the number of blood gases and chest radiographs in preterm, ventilated infants.

METHODS

Infants were studied on two consecutive days for 12 hours on each day. They were randomised to receive standard care (standard period) or standard care with a closed loop automated oxygen control system (automated oxygen control period) first.

RESULTS

Twenty-four infants with a median gestational age of 25.7 (range 23.1-32.6) weeks were studied at a median postconceptional age of 27.4 (range 24.3-34.9) weeks. During the automated oxygen control period, there were fewer desaturations that lasted >30 seconds (P = .032) or >60 seconds (P = .002), infants spent a higher proportion of the time within their target SpO₂ range during the automated oxygen control period (P < .001), and fewer manual adjustments were made to the inspired oxygen concentration (mean 0.58 vs mean 11.29) (P < .001). There were no significant differences in the number of blood gases (P = .872) or chest radiographs (P = .366) between the two periods.

CONCLUSION

Closed loop automated oxygen delivery resulted in fewer prolonged desaturations with more time spent in the targeted oxygen range.

Automatic oxygen flow titration in spontaneously breathing children: An open-label randomized controlled pilot study

INTRODUCTION

When children require supplemental oxygen due to acute hypoxemic respiratory distress (AHRD), manual control of the oxygen flow is often difficult and time-consuming, and carries the risk of unrecognized hypoxia and hyperoxia. To date, no automatic oxygen titration system has been developed and evaluated in spontaneously breathing children.

METHODS

Children between 1 month and 15 years of age receiving supplemental oxygen due to AHRD were recruited within 24 hours following the onset of the O₂ administration in a French University Department of Paediatrics. Patients were randomized to receive either automated oxygen administration using the FreeO2 device, or conventional manual oxygen administration over a maximum period of 6 hours. Stratification was performed to classify the patients into two age groups: 1 month to 2 years of age and 2 to 15 years of age. The primary outcome was % time spent within the SpO₂ target range (92%-98%).

RESULTS

60 patients (30 infants, 30 children) were randomized and 55 could be analyzed for the primary outcome (28 automated, 27 manual). The automated O₂ delivery using the FreeO2 device significantly increased the time spent within the predefined SpO₂ range (94.6% ± 6% vs 76.3% ± 22%, difference [95% confidence interval {CI}] 18.4 [10.1; 26.7]) with less time spent with hypoxemia (1% ± 1.1% vs 15.1% ± 21.8%, difference [95% CI] -14.4 [-22.2; -6.7]). This difference was greater among (2-15 years of age) children, compared to (1 month-2 years of age) infants.

CONCLUSIONS

The present randomized controlled pilot study indicates that the tested automated closed-loop O₂ titration technology was safe and yielded improved oxygen parameters among spontaneously breathing children. Based on our pilot data, a full randomized controlled trial will be required to verify the potential clinical benefits.

Closed loop automated oxygen control in neonates-A review

AIM

Neonates frequently require supplementary oxygen but may develop complications if the oxygen saturation is outside the target range. This review aimed to determine whether the algorithms used in closed loop automated oxygen control systems influenced their efficacy and whether use of the systems reduced relevant, long-term neonatal complications.

METHODS

A literature search was conducted using PubMed and Google Scholar. The search terms were 'closed loop' or 'automat*', 'oxygen' and 'neonat*'.

RESULTS

Eighteen studies were identified: sixteen comparison clinical studies, an observational study and an animal study. Overall, closed loop automated oxygen control was associated with an increased percentage of time spent within the target oxygen saturation range and there were fewer manual adjustments to the inspired oxygen concentration when compared with manual oxygen control. The systems were effective in infants on non-invasive respiratory support or mechanically ventilated, but no study included term-born infants. No long-term data were available to determine if complications of oxygen toxicity were reduced.

CONCLUSION

Closed loop automated oxygen control has been shown in short term trials including preterm and low birth weight infants to improve target saturation achievement. Whether long-term outcomes will be improved with their use requires investigation.

Continuous vital sign analysis for predicting and preventing neonatal diseases in the twenty-first century: big data to the forefront

In the neonatal intensive care unit (NICU), heart rate, respiratory rate, and oxygen saturation are vital signs (VS) that are continuously monitored in infants, while blood pressure is often monitored continuously immediately after birth, or during critical illness. Although changes in VS can reflect infant physiology or circadian rhythms, persistent deviations in absolute values or complex changes in variability can indicate acute or chronic pathology. Recent studies demonstrate that analysis of continuous VS trends can predict sepsis, necrotizing enterocolitis, brain injury, bronchopulmonary dysplasia, cardiorespiratory decompensation, and mortality. Subtle changes in continuous VS patterns may not be discerned even by experienced clinicians reviewing spot VS data or VS trends captured in the monitor. In contrast, objective analysis of continuous VS data can improve neonatal outcomes by allowing heightened vigilance or preemptive interventions. In this review, we provide an overview of the studies that have used continuous analysis of single or multiple VS, their interactions, and combined VS and clinical analytic tools, to predict or detect neonatal pathophysiology. We make the case that big-data analytics are promising, and with continued improvements, can become a powerful tool to mitigate neonatal diseases in the twenty-first century.

Dutch Neonatal Intensive Care Nurses' Perceptions of Pulse Oximeter Saturation Target Limits for Preterm Infants

PURPOSE

To conduct a national survey to assess practice, knowledge, barriers, and perceptions regarding oxygen saturation (SpO₂) target limits among Dutch neonatal intensive care unit (NICU) nurses.

DESIGN AND METHODS

Cross-sectional, web-based survey among 667 nurses from 9 level 3 Dutch NICUs. Part of the questions were based on a clinical scenario (28-weeks preterm infant, treated with CPAP, FiO₂ 0.4).

RESULTS

328 (53.6%) nurses responded to the survey. Of these, 281 (85.7%) reported to know the local policy of SpO₂ target limits, and 261 (79.6%) and 244 (74.4%) rightly identified the lower and upper limit, respectively. Six NICUs recently increased their lower SpO₂ limit and for 62.0% of their nurses this led to a significant alarm increase. For the majority of the respondents, the baby from the clinical scenario would spend <10% of the time outside the lower or upper SpO₂ limits. Automated oxygen control systems were considered a good idea by 59.2% of the respondents, but 53.9% considered allowing parents to participate in FiO₂ titration a bad or very bad idea_. CONCLUSIONS: The majority of the respondents identified their unit's policy-specified SpO₂ target limits and reported that the increase in SpO₂ target limits may have led to more alarms. Titration of FiO₂ is a part of care that respondents were reluctant to share with parents.

PRACTICE IMPLICATIONS

A potential increase in the number of SpO₂ alarms may lead to alarm fatigue. Although family-centered care philosophy is widely accepted across Dutch NICUs, there are still barriers to overcome.

Targeting Arterial Oxygen Saturation by Closed-Loop Control of Inspired Oxygen in Preterm Infants

Exposure to hyperoxemia from excessive oxygen supplementation and episodes of intermittent hypoxemia have been associated with damage to the eye, lung, and central nervous system in premature infants. The inherent respiratory instability of the premature infant combined with limited staffing or equipment resources often affect SpO₂ targeting and increase exposure to extreme SpO₂ levels. Multiple systems for closed loop control of inspired oxygen have been developed to improve SpO₂ targeting. This article reviews the evidence provided by clinical studies evaluating the efficacy of these systems in extreme premature infants.

Automated control of inspired oxygen (FiO2 ) in preterm infants: Literature review

The vast majority (95%) of very preterm infants receive oxygen-therapy monitored by oxygen pulse saturation (SpO₂ ). However, they spend a significant percentage of time out of the SpO₂ target with a high risk of severe complications such as bronchopulmonary dysplasia (BPD) and retinopathy of prematurity (ROP). Recently, systems allowing the automated control of inspired oxygen (FiO₂ ) for patient delivery to maintain target SpO₂ has been become commercially available. We reviewed literature and individuated sixteen studies on the effectiveness of automated control of FiO₂ in preterm infants. These studies demonstrate that automated devices are significantly more effective than manual control in maintaining target SpO₂ and in preventing hyperoxia, while they seem to be less effective in preventing hypoxia. The studies were very heterogeneous for design, population size, duration, and device used, and this precludes firm conclusions regarding effectiveness and best setting of these systems. Moreover, none of the studies investigated if automated control of FiO₂ can actually improve outcome in preterm infants. We conclude that further large-scale studies are warranted to assess the actual clinical relevance of these devices and to decide if they should become the standard of care.

Continuous pulse oximetry and respiratory rate trends predict short-term respiratory and growth outcomes in premature infants

BACKGROUND

To examine the correlation between interval vital signs recorded by nursing staff and continuous monitor recordings, and to determine whether aggregated monitor recordings can better predict impending escalation of respiratory support in premature infants.

METHOD

Preterm infants on noninvasive respiratory support or room air (RA) were prospectively enrolled. Nursing-and monitor-recorded pulse oximetry (SpO2) and respiratory rates (RR) data were recorded daily.

RESULTS

Ninety four infants were recruited with median gestational age of 32 weeks and birth weight of 1848 g. > 3 × 10⁶ data points were analyzed over 2204 patient days. Median events/day recorded was 8 (nursing) and 1424 (monitor) per infant. We did not find a strong correlation between monitor- and nursing events of tachypnea (RR > 70) and hypoxia (SpO2 < 90%). Infants with monitor-recorded hypoxia for > 5%/day (p < 0.0001) or tachypnea for > 30%/day (p < 0.0001) were more likely to require an increase in respiratory support within next 3 days. Monitor-recorded hypoxia and tachypnea were also associated with poor weight gain.

CONCLUSIONS

Monitor-recorded trends for tachypnea and oxygen saturations < 90% were able to predict short-term respiratory outcomes, and were associated with growth outcomes. This study emphasizes the potential for monitor-recorded data to augment clinical decision making at the bedside.

Effect of a smaller target range on the compliance in targeting and distribution of oxygen saturation in preterm infants

BACKGROUND

Following recent recommendations, the oxygen saturation (SpO₂) target range for preterm infants in our nursery was narrowed towards the higher end from 85%-95% to 90%-95%. We determined the effect of narrowing the SpO₂ target range on the compliance in target range and distribution of SpO₂ in preterm infants.

METHODS

Before and after changing the target range from 85%-95% to 90%-95%, infants <30 weeks of gestation receiving oxygen were compared during their admission on the neonatal intensive care unit. For each infant, distribution of SpO₂ was noted by collecting SpO₂ samples each minute, and the percentage of time spent with SpO₂ within 90%-95% was calculated. Oxygen was manually adjusted. Hypoxaemic events (SpO₂ <80%) where oxygen was titrated were analysed.

RESULTS

Data were analysed for 104 infants (57 before and 47 after the range was narrowed). The narrower range was associated with an increase in the median (IQR) SpO₂ (93% (91%-96%) vs 94% (92%-97%), p=0.01), but no increase in median time SpO₂ within 90%-95% (49.2% (39.6%-59.7%) vs (46.9% (27.1%-57.9%), p=0.72). The distribution of SpO₂ shifted to the right with a significant decrease in SpO₂ <90%, but not <80%. The count of minute values for Sp0₂ <80% decreased, while the frequency and duration of hypoxaemic events and oxygen titration were not different.

CONCLUSION

Narrowing the target range from 85%-95% to 90%-95% in preterm infants was associated with an increase in median SpO₂ and a rightward shift in the distribution, but no change in time spent between 90% and 95%.

Automated versus manual control of inspired oxygen to target oxygen saturation in preterm infants: a systematic review and meta-analysis

OBJECTIVES

To conduct a systematic review of clinical trials comparing automated versus manual fraction of inspired oxygen (FiO₂) control to target oxygen saturation (SpO₂) in preterm infants.

DESIGN

The authors searched MEDLINE, Embase, CENTRAL, and CINAHL from inception upto December 2016, reviewed conference proceedings and sought results of unpublished trials. Studies were included if automated FiO₂ control was compared to manual control in preterm infants on positive pressure respiratory support. The primary outcome was percentage of time spent within the target SpO₂ range. Summary mean differences (MD) were computed using random effects model.

RESULTS

Out of 276 identified studies 10 met the inclusion criteria. Automated FiO₂ control significantly improved time being spent within the target SpO₂ range [MD: 12.8%; 95% CI: 6.5-19.2%; I² = 90%]. Periods of hyperoxia (MD:-8.8%; 95% CI: -15 to -2.7%), severe hypoxia(SpO₂ < 80%)(MD: -0.9%;95%CI: -1.5 to -0.4%) and hypoxic events (MD: -5.6%; 95% CI: -9.1 to -2.1%) were significantly reduced with automated control.

CONCLUSION

Automated FiO₂ adjustment provides significant improvement of time in target saturations, reduces periods of hyperoxia, and severe hypoxia in preterm infants on positive pressure respiratory support.

Pulse oximetry values of neonates admitted for care and receiving routine oxygen therapy at a resource-limited hospital in Kenya

AIM

There are 2.7 million neonatal deaths annually, 75% of which occur in sub-Saharan Africa and South Asia. Effective treatment of hypoxaemia through tailored oxygen therapy could reduce neonatal mortality and prevent oxygen toxicity.

METHODS

We undertook a two-part prospective study of neonates admitted to a neonatal unit in Nairobi, Kenya, between January and December 2015. We determined the prevalence of hypoxaemia and explored associations of clinical risk factors and signs of respiratory distress with hypoxaemia and mortality. After staff training on oxygen saturation (SpO₂ ) target ranges, we enrolled a consecutive sample of neonates admitted for oxygen and measured SpO₂ at 0, 6, 12, 18 and 24 h post-admission. We estimated the proportion of neonates outside the target range (≥34 weeks: ≥92%; <34 weeks: 89-93%) with 95% confidence intervals (CIs).

RESULTS

A total of 477 neonates were enrolled. Prevalence of hypoxaemia was 29.2%. Retractions (odds ratio (OR) 2.83, 95% CI 1.47-5.47), nasal flaring (OR 2.68, 95% CI 1.51-4.75), and grunting (OR 2.47, 95% CI 1.27-4.80) were significantly associated with hypoxaemia. Nasal flaring (OR 2.85, 95% CI 1.25-6.54), and hypoxaemia (OR 3.06, 95% CI 1.54-6.07) were significantly associated with mortality; 64% of neonates receiving oxygen were out of range at ≥2 time points and 43% at ≥3 time points.

CONCLUSION

There is a high prevalence of hypoxaemia at admission and a strong association between hypoxaemia and mortality in this Kenyan neonatal unit. Many neonates had out of range SpO₂ values while receiving oxygen. Further research is needed to test strategies aimed at improving the accuracy of oxygen provision in low-resource settings.

A model for oxygen conservation associated with titration during pediatric oxygen therapy

BACKGROUND

Continuous oxygen treatment is essential for managing children with hypoxemia, but access to oxygen in low-resource countries remains problematic. Given the high burden of pneumonia in these countries and the fact that flow can be gradually reduced as therapy progresses, oxygen conservation through routine titration warrants exploration.

AIM

To determine the amount of oxygen saved via titration during oxygen therapy for children with hypoxemic pneumonia.

METHODS

Based on published clinical data, we developed a model of oxygen flow rates needed to manage hypoxemia, assuming recommended flow rate at start of therapy, and comparing total oxygen used with routine titration every 3 minutes or once every 24 hours versus no titration.

RESULTS

Titration every 3 minutes or every 24 hours provided oxygen savings estimated at 11.7% ± 5.1% and 8.1% ± 5.1% (average ± standard error of the mean, n = 3), respectively. For every 100 patients, 44 or 30 kiloliters would be saved-equivalent to 733 or 500 hours at 1 liter per minute.

CONCLUSIONS

Ongoing titration can conserve oxygen, even performed once-daily. While clinical validation is necessary, these findings could provide incentive for the routine use of pulse oximeters for patient management, as well as further development of automated systems.

Clinical evaluation of a novel adaptive algorithm for automated control of oxygen therapy in preterm infants on non-invasive respiratory support

OBJECTIVE

To evaluate the performance of a novel rapidly responsive proportional-integral-derivative (PID) algorithm for automated oxygen control in preterm infants with respiratory insufficiency.

DESIGN

Interventional study of a 4-hour period of automated oxygen control compared with combined data from two flanking periods of manual control (4 hours each).

SETTING

Neonatal intensive care unit.

PARTICIPANTS

Preterm infants (n=20) on non-invasive respiratory support and supplemental oxygen, with oxygen saturation (SpO₂) target range 90%-94% (manual control) and 91%-95% (automated control). Median gestation at birth 27.5 weeks (IQR 26-30 weeks), postnatal age 8.0 (1.8-34) days.

INTERVENTION

Automated oxygen control using a standalone device, receiving SpO₂ input from a standard oximeter and computing alterations to oxygen concentration that were actuated with a modified blender. The PID algorithm was enhanced to avoid iatrogenic hyperoxaemia and adapt to the severity of lung dysfunction.

MAIN OUTCOME MEASURE

Proportion of time in the SpO₂ target range, or above target range when in air.

RESULTS

Automated oxygen control resulted in more time in the target range or above in air (manual 56 (48-63)% vs automated 81 (76-90)%, p<0.001) and less time at both extremes of oxygenation. Prolonged episodes of hypoxaemia and hyperoxaemia were virtually eliminated. The control algorithm showed benefit in every infant. Manual changes to oxygen therapy were infrequent during automated control (0.24/hour vs 2.3/hour during manual control), and oxygen requirements were unchanged (automated control period 27%, manual 27% and 26%, p>0.05).

CONCLUSIONS

The novel PID algorithm was very effective for automated oxygen control in preterm infants, and deserves further investigation.

Development and preclinical testing of an adaptive algorithm for automated control of inspired oxygen in the preterm infant

OBJECTIVE

To assess the performance of a novel algorithm for automated oxygen control using a simulation of oxygenation founded on in vivo data from preterm infants.

METHODS

A proportional-integral-derivative (PID) control algorithm was enhanced by (i) compensation for the non-linear SpO₂-PaO₂ relationship, (ii) adaptation to the severity of lung dysfunction and (iii) error attenuation within the target range. Algorithm function with and without enhancements was evaluated by iterative linking with a computerised simulation of oxygenation. Data for this simulation (FiO₂ and SpO₂ at 1 Hz) were sourced from extant recordings from preterm infants (n=16), and converted to a datastream of values for ventilation:perfusion ratio and shunt. Combination of this datastream second by second with the FiO₂ values from the algorithm under test produced a sequence of novel SpO₂ values, allowing time in the SpO₂ target range (91%-95%) and in various degrees of hypoxaemia and hyperoxaemia to be determined. A PID algorithm with 30 s lockout after each FiO₂ adjustment, and a proportional-derivative (PD) algorithm were also evaluated.

RESULTS

Separate addition of each enhancing feature to the PID algorithm showed a benefit, but not with uniformly positive effects. The fully enhanced algorithm was optimal for the combination of targeting the desired SpO₂ range and avoiding time in, and episodes of, hypoxaemia and hyperoxaemia. This algorithm performed better than one with a 30 s lockout, and considerably better than PD control.

CONCLUSIONS

An enhanced PID algorithm was very effective for automated oxygen control in a simulation of oxygenation, and deserves clinical evaluation.

Improving manual oxygen titration in preterm infants by training and guideline implementation

To study oxygen saturation (SpO₂) targeting before and after training and guideline implementation of manual oxygen titration, two cohorts of preterm infants <30 weeks of gestation needing respiratory support and oxygen therapy were compared. The percentage of the time spent with SpO₂ within the target range (85-95%) was calculated (%SpO₂-wtr). SpO₂ was collected every minute when oxygen is >21%. ABCs where oxygen therapy was given were identified and analyzed. After training and guideline implementation the %SpO₂-wtr increased (median interquartile range (IQR)) 48.0 (19.6-63.9) % vs 61.9 (48.5-72.3) %; p < 0.005, with a decrease in the %SpO₂ > 95% (44.0 (27.8-66.2) % vs 30.8 (22.6-44.5) %; p < 0.05). There was no effect on the %SpO₂ < 85% (5.9 (2.8-7.9) % vs 6.2 (2.5-8) %; ns) and %SpO₂ < 80% (1.9 (1.0-3.0) % vs 1.7 (0.8-2.6) %; ns). In total, 186 ABCs with oxygen therapy before and 168 ABCs after training and guideline implementation occurred. The duration of SpO₂ < 80% reduced (2 (1-2) vs 1 (1-2) minutes; p < 0.05), the occurrence of SpO₂ > 95% did not decrease (73% vs 64%; ns) but lasted shorter (2 (0-7) vs 1 (1-3) minute; p < 0.004).

CONCLUSION

Training and guideline implementation in manual oxygen titration improved SpO₂ targeting in preterm infants with more time spent within the target range and less frequent hyperoxaemia. The durations of hypoxaemia and hyperoxaemia during ABCs were shorter. What is Known: • Oxygen saturation targeting in preterm infants can be challenging and the compliance is low when oxygen is titrated manually. • Hyperoxaemia often occurs after oxygen therapy for oxygen desaturation during apnoeas. What is New: • Training and implementing guidelines improved oxygen saturation targeting and reduced hyperoxaemia. • Training and implementing guidelines improved manual oxygen titration during ABC.

Design and Construction of a Microcontroller-Based Ventilator Synchronized with Pulse Oximeter

This study aims to introduce a novel device with which mechanical ventilator and pulse oximeter work in synchronization. Serial communication technique was used to enable communication between the pulse oximeter and the ventilator. The SpO2 value and the pulse rate read on the pulse oximeter were transmitted to the mechanical ventilator through transmitter (Tx) and receiver (Rx) lines. The fuzzy-logic-based software developed for the mechanical ventilator interprets these values and calculates the percentage of oxygen (FiO2) and Positive End-Expiratory Pressure (PEEP) to be delivered to the patient. The fuzzy-logic-based software was developed to check the changing medical states of patients and to produce new results (FiO2 ve PEEP) according to each new state. FiO2 and PEEP values delivered from the ventilator to the patient can be calculated in this way without requiring any arterial blood gas analysis. Our experiments and the feedbacks from physicians show that this device makes it possible to obtain more successful results when compared to the current practices.

Oxygen Use in Neonatal Care: A Two-edged Sword

In the neonatal period, the clinical use of oxygen should be taken into consideration for its beneficial and toxicity effects. Oxygen toxicity is due to the development of reactive oxygen species (ROS) such as OH^• that is one of the strongest oxidants in nature. Of note, generation of ROS is a normal occurrence in human and it is involved in a myriad of physiological reactions. Anyway an imbalance between production of oxidant species and antioxidant defenses, called oxidative stress, could affect various aspect of organisms' physiology and it could determine pathological consequences to living beings. Neonatal oxidative stress is essentially due to decreased antioxidants, increased ROS, or both. Studies have demonstrated that antioxidant capacity is lower in preterm newborns than term babies. This well-known deficiency of antioxidant factors is only a piece of a cohort of factors, which can be involved in the neonatal oxidative stress and the increased production of ROS may be a main factor. Mechanisms of ROS generation are: mitochondrial respiratory chain, free iron and Fenton reaction, inflammation, hypoxia and/or ischemia, reperfusion, and hyperoxia. Oxidative stress following hyperoxia has been recognized to be responsible for lung, central nervous system, retina, red blood cell injuries, and possibly generalized tissue damage. When supplemental oxygen is needed for care, it would be prudent to avoid changes and fluctuations in SpO₂. The definition of the safest level of oxygen saturations in the neonate remains an area of active research. Currently, on the basis of the published evidences, the most suitable approach would be to set alarm limits between 90 and 95%. It should allow to avoid SpO₂ values associated with potential hypoxia and/or hyperoxia. Although the usefulness of antioxidant protection in the neonatal period is still under investigation, the risk of tissue damage due to oxidative stress in perinatal period should not be underestimated.

Characterisation of the Oxygenation Response to Inspired Oxygen Adjustments in Preterm Infants

BACKGROUND

Oxygen saturation (SpO2) targeting in the preterm infant may be improved with a better understanding of the SpO2 responses to changes in inspired oxygen (FiO2).

OBJECTIVE

We investigated the first-order FiO2-SpO2 relationship, aiming to quantify the parameters governing that relationship, the influences on these parameters and their variability.

METHODS

In recordings of FiO2 and SpO2 from preterm infants on continuous positive airway pressure and supplemental oxygen, we identified unique FiO2 adjustments and mapped the subsequent SpO2 responses. For responses identified as first-order, the delay, time constant and gain parameters were determined. Clinical and physiological predictors of these parameters were sought in regression analysis, and intra- and inter-subject variability was evaluated.

RESULTS

In 3,788 h of available data from 47 infants at 31 (28-33) post-menstrual weeks [median (interquartile range)], we identified 993 unique FiO2 adjustments followed by a first-order SpO2 response. All response parameters differed between FiO2 increments and decrements, with increments having a shorter delay, longer time constant and higher gain [2.9 (1.7-4.8) vs. 1.3 (0.58-2.6), p < 0.05]. Gain was also higher in less mature infants and in the setting of recent SpO2 instability, and was diminished with increasing severity of lung dysfunction. Intra-subject variability in all parameters was prominent.

CONCLUSIONS

First-order SpO2 responses show variable gain, influenced by the direction of FiO2 adjustment and the severity of lung disease, as well as substantial intra-subject parameter variability. These findings should be taken into account in adjustment of FiO2 for SpO2 targeting in preterm infants.

Closed-loop control of inspired oxygen in premature infants

Systems for closed-loop control of inspired oxygen have been developed to improve the maintenance of oxygenation targets in premature infants and reduce hyperoxemia, hypoxemia, and exposure to high inspired oxygen levels. This review describes some of the clinical studies that have evaluated the efficacy of these systems in oxygen targeting.

Sojourn in excessively high oxygen saturation ranges in individual, very low-birthweight neonates

AIM

To investigate the variability in sojourn times at high oxygen saturations (SpO2 ) in individual patients and to examine whether there are subsets of patients or treatments that are associated with differing sojourn times at SpO2 ≥93%.

METHODS

Pulse oximetry data (Masimo) were studied in 71 premature babies receiving supplemental oxygen. Outcome measure was proportion of time per 12-h shift that individual babies spent in the range SpO2 ≥93%. We studied whether an inordinate proportion of time spent at SpO2 ≥93% was attributable to any subset of babies, mode of ventilation or nursing shifts, whether sojourn times were statistically independent shift-to-shift and whether an educational intervention reduced the amount of time spent at SpO2 ≥93%.

RESULTS

The proportion of time spent by the populations overall at SpO2 ≥93% was distributed equally among babies. However, high-frequency ventilation was associated with the least amount of time at SpO2 ≥93% compared with other modes of respiratory support (p < 0.0001), while nasal cannulae were associated with the highest proportion of time at SpO2 ≥93% (p < 0.001).

CONCLUSION

Measures to improve compliance with targeted SpO2 ranges should be applied universally although further improvement may be achieved by specifically targeting babies receiving supplemental oxygen via nasal cannula.

Compliance in oxygen saturation targeting in preterm infants: a systematic review

During oxygen therapy in preterm infants, targeting oxygen saturation is important for avoiding hypoxaemia and hyperoxaemia, but this can be very difficult and challenging for neonatal nurses. We systematically reviewed the qualitative and quantitative studies investigating the compliance in targeting oxygen saturation in preterm infants and factors that influence this compliance. We searched PubMed, Embase, Web of Science, Cochrane, CINAHL and ScienceDirect from 2000 to January 2015. Sixteen studies were selected, which involved a total of 2935 nurses and 574 infants. The studies varied in methodology, and we have therefore used a narrative account to describe the data. The main finding is that there is a low compliance in oxygen targeting; the upper alarm limits are inappropriately set, and maintaining the saturation (SpO2) below the upper limit presented particular difficulties. Although there is little data available, the studies indicate that training, titration protocols and decreasing workload could improve awareness and compliance. Automated oxygen regulations have been shown to increase the time that SpO2 is within the target range.

CONCLUSION

The compliance in targeting oxygen during oxygen therapy in preterm infants is low, especially in maintaining the SpO2 below the upper limit.

WHAT IS KNOWN

• The use of oxygen in preterm infants is vital, but the optimal strategyremains controversial. • Targeting SpO2 during oxygen therapy in preterm infants has beenshown to reduce mortality and morbidity.

WHAT IS NEW

• Review of the literature showed that the compliance in targeting SpO2and alarm settings is low. • Creating awareness of risks of oxygen therapy and benefits in targeting,decreasing nurse/patient ratio and automated oxygen therapy couldincrease compliance.

Safe oxygen saturation targeting and monitoring in preterm infants: can we avoid hypoxia and hyperoxia?

Oxygen is a neonatal health hazard that should be avoided in clinical practice. In this review, an international team of neonatologists and nurses assessed oxygen saturation (SpO₂) targeting in preterm infants and evaluated the potential weaknesses of randomised clinical trials.