Overcoming barriers to oxygen saturation targeting

Care Bundle to Improve Oxygen Maintenance and Events

Prolonged periods spent outside the target range of oxygen saturation (SpO₂) in preterm infants, along with frequent desaturation events, predispose them to retinopathy of prematurity (ROP) and long-term neurodevelopmental impairment. The primary aim of this study was to increase the mean time spent within the target SpO₂ range (WTR) by 10% and to reduce the frequency of desaturation events by 5 events per patient day, respectively, within 18 months of implementing a care bundle.

Methods

This study was completed in a 46-bed neonatal intensive care unit (NICU), involving 246 staff members and led by a quality improvement team. The change interventions included implementing new practice guidelines, reviewing daily summaries of SpO₂ maintenance, daily infant wellness assessment, standardizing workflow, and responding to SpO₂ alarms. In addition, we collected staff satisfaction and compliance with change interventions, resource use, and morbidity and mortality data at discharge.

Results

The mean time spent WTR increased from 65.3% to 75.3%, and the frequency of desaturation events decreased from 25.1 to 16.5 events per patient day, respectively, with a higher magnitude of benefit in infants on days with supplemental oxygen. Postimplementation, the duration of high-frequency ventilation and supplemental oxygen were lower, but morbidity and mortality rates were similar. Staff satisfaction with training workshops, coaching, use of the infant wellness assessment tool, and SpO₂ alarm management algorithms were 74%, 82%, 80%, and 74%, respectively.

Conclusion

Implementing a care bundle to improve oxygen maintenance and reduce desaturation events increased the time spent WTR and reduced the frequency of desaturation events.

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.

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.

Environmental or Nasal Cannula Supplemental Oxygen for Preterm Infants: A Randomized Cross-Over Trial

OBJECTIVE

To test the hypothesis that environmental compared with nasal cannula oxygen decreases episodes of intermittent hypoxemia (oxygen saturations <85% for ≥10 seconds) in preterm infants on supplemental oxygen by providing a more stable hypopharyngeal oxygen concentration.

STUDY DESIGN

This was a single center randomized crossover trial with a 1:1 parallel allocation to order of testing. Preterm infants on supplemental oxygen via oxygen environment maintained by a servo-controlled system or nasal cannula with flow rates ≤1.0 L per kg per minute were crossed over every 24 hours for 96 hours. Data were collected electronically to capture real time numeric and waveform data from patient monitors.

RESULTS

Twenty-five infants with gestational age of 27 ± 2 weeks (mean ± SD) and a birth weight of 933 ± 328 g were studied at postnatal day 36 ± 26. The number of episodes of intermittent hypoxemia per 24 hours was 117 ± 77 (median, 98; range, 4-335) with oxygen environment vs 130 ± 63 (median, 136; range, 16-252) with nasal cannula (P = .002). Infants on oxygen environment compared with nasal cannula also had decreased episodes of severe intermittent hypoxemia (P = .005). Infants on oxygen environment compared with nasal cannula had a lower proportion of time with oxygen saturations <85% (.05 ± .03 vs .06 ± .03, P < .001), and a lower coefficient of variation of oxygen saturation (P = .02).

CONCLUSIONS

In preterm infants receiving supplemental oxygen, servo-controlled oxygen environment decreases hypoxemia compared with nasal cannula.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02794662.

Engineering Evaluation of the Performance of an Automatic Peripheral Oxygen Controller Using a Neonatal Respiratory Model

Premature infants often require respiratory support with a varying concentration of the fraction of inspired oxygen FiO2 to keep the arterial oxygen saturation typically measured using a peripheral sensor (SpO2) within the desired range to avoid both hypoxia and hyperoxia. The widespread practice for controlling the fraction of inspired oxygen is by manual adjustment. Automatic control of the oxygen to assist care providers is desired. A novel closed-loop respiratory support device with dynamic adaptability is evaluated nonclinically by using a neonatal respiratory response model. The device demonstrated the ability to improve oxygen saturation control over manual control by increasing the proportion of time where SpO2 is within the desired range while minimizing the episodes and periods where SpO2 of the neonatal respiratory model is out of the target range.

Diagnostic Approach to Pulmonary Hypertension in Premature Neonates

Bronchopulmonary dysplasia (BPD) is a form of chronic lung disease in premature infants following respiratory distress at birth. With increasing survival of extremely low birth weight infants, alveolar simplification is the defining lung characteristic of infants with BPD, and along with pulmonary hypertension, increasingly contributes to both respiratory morbidity and mortality in these infants. Growth restricted infants, infants born to mothers with oligohydramnios or following prolonged preterm rupture of membranes are at particular risk for early onset pulmonary hypertension. Altered vascular and alveolar growth particularly in canalicular and early saccular stages of lung development following mechanical ventilation and oxygen therapy, results in developmental lung arrest leading to BPD with pulmonary hypertension (PH). Early recognition of PH in infants with risk factors is important for optimal management of these infants. Screening tools for early diagnosis of PH are evolving; however, echocardiography is the mainstay for non-invasive diagnosis of PH in infants. Cardiac computed tomography (CT) and magnetic resonance are being used as imaging modalities, however their role in improving outcomes in these patients is uncertain. Follow-up of infants at risk for PH will help not only in early diagnosis, but also in appropriate management of these infants. Aggressive management of lung disease, avoidance of hypoxemic episodes, and optimal nutrition determine the progression of PH, as epigenetic factors may have significant effects, particularly in growth-restricted infants. Infants with diagnosis of PH are managed with pulmonary vasodilators and those resistant to therapy need to be worked up for the presence of cardio-vascular anomalies. The management of infants and toddlers with PH, especially following premature birth is an emerging field. Nonetheless, combination therapies in a multi-disciplinary setting improves outcomes for these infants.

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.

Improving the detectability of oxygen saturation level targets for preterm neonates: A laboratory test of tremolo and beacon sonifications

Recent guidelines recommend oxygen saturation (SpO2) levels of 90%-95% for preterm neonates on supplemental oxygen but it is difficult to discern such levels with current pulse oximetry sonifications. We tested (1) whether adding levels of tremolo to a conventional log-linear pulse oximetry sonification would improve identification of SpO2 ranges, and (2) whether adding a beacon reference tone to conventional pulse oximetry confuses listeners about the direction of change. Participants using the Tremolo (94%) or Beacon (81%) sonifications identified SpO2 range significantly more accurately than participants using the LogLinear sonification (52%). The Beacon sonification did not confuse participants about direction of change. The Tremolo sonification may have advantages over the Beacon sonification for monitoring SpO2 of preterm neonates, but both must be further tested with clinicians in clinically representative scenarios, and with different levels of ambient noise and distractions.

Oxygen Targeting in Extremely Low Birth Weight Infants

The use of supplemental oxygen plays a vital role in the care of the critically ill preterm infant, but the unrestricted use of oxygen can lead to unintended harms, such as chronic lung disease and retinopathy of prematurity. An overly restricted use of supplemental oxygen may have adverse effects as well. Ideally, continuous monitoring of tissue and cellular oxygen delivery would allow clinicians to better titrate the use of supplemental oxygen, but such monitoring is not currently feasible in the clinical setting. The introduction of pulse oximetry has greatly aided the clinician by providing a relatively easy and continuous estimate of arterial oxygen saturation, but pulse oximetry has several practical, technical, and physiologic limitations. Recent randomized clinical trials comparing different pulse oximetry targets have been conducted to better inform the practice of supplemental oxygen use. This clinical report discusses the benefits and limitations of pulse oximetry for assessing oxygenation, summarizes randomized clinical trials of oxygen saturation targeting, and addresses implications for practice.

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.

Advances in respiratory support for high risk newborn infants

BACKGROUND

A significant proportion of premature infants present with respiratory failure early in life and require supplemental oxygen and some form of mechanical respiratory support.

FINDINGS

Many technical advances in the devices for neonatal respiratory support have occurred in recent years and new management strategies have been developed and evaluated in this population. This article describes some of these novel methods and discusses their application and possible advantages and limitations.

CONCLUSION

Newer methods of respiratory support have led to marked improvement in outcome of premature infants with respiratory failure. Some of these strategies are very promising but further investigation to evaluate their short term efficacy and impact on long term respiratory and other relevant outcomes is needed before wider use.

Current concepts of oxygen therapy in neonates

Use of high oxygen concentrations in treating neonatal illness has been challenged in the past few decades. In the face of evidence suggesting adverse outcomes (both clinical and biochemical) with use of high oxygen concentrations, the current guidelines appear to favour use of the lowest possible concentrations of oxygen for the shortest time to treat ill neonates. Current delivery room guidelines recommend using room air when initiating positive pressure ventilation during resuscitation. Targeting appropriate oxygen saturation when delivering supplemental oxygen, both in the delivery room and neonatal intensive care unit (NICU), are now the new emerging standards in neonatal care. Investments in good quality pulse oximeters and oxygen blenders in neonatal care units is now seen as critical to improve newborn survival.

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.

A randomised crossover trial of clinical algorithm for oxygen saturation targeting in preterm infants with frequent desaturation episodes

OBJECTIVES

Strategies for oxygen therapy for preterm infants, such as the Vermont-Oxford's 'Breathsavers' guidelines, seek to strike a balance between the potential risks of the extremes of hyperoxia and hypoxia in preterm infants. Using an algorithm based on those guidelines, we aimed to compare the proportion of time spent within the SpO2 target range during algorithm-based management of oxygen delivery compared with routine nursing care.

STUDY DESIGN

In a randomised crossover trial, maintenance of SpO2 over a 4-hour period during routine care was compared with algorithm-based control (administered by a dedicated research nurse). SpO2 target (88-92%) and alarm limits (86-94%) were identical in both arms. Infants <32 weeks' gestation were eligible if having >8 desaturations episodes to <85%/4 h while receiving continuous positive airway pressure/synchronised intermittent mandatory ventilation. Data was recorded via the Powerlab system from Masimo oximeters and Babylog 8000+ ventilators.

RESULTS

16 infants with a gestation of 26.7 ± 1.3 weeks (mean ± SD) and birth weight 901 ± 193 g were studied at a postmenstrual age of 30.5 ± 2.4 weeks. The percentage of time spent within target range was 34.6 ± 28.5% during routine care versus 38.3 ± 29.3% during algorithm-based care (p = 0.23). Compliance with alarm limits was 58.4 ± 21.8% during routine versus 64.7 ± 22.1% for algorithm-based care (p = 0.091). The frequency of desaturations, episode severity or number of FiO2 adjustments did not differ between the two care strategies.

CONCLUSIONS

The observation that algorithm-based control did not improve time spent within the SpO2 target and alarm limits suggests nursing care has reached an optimum in the unit studied. Our finding indicates that significant modifications to the algorithm are likely to be necessary to improve target range compliance.

The risk for hyperoxaemia after apnoea, bradycardia and hypoxaemia in preterm infants

OBJECTIVE

To investigate the occurrence and duration of oxygen saturation (SpO₂) ≥95%, after extra oxygen for apnoea, bradycardia, cyanosis (ABC), and the relation with the duration of bradycardia and/or SpO₂ ≤80%.

METHODS

All preterm infants <32 weeks' gestation supported with nasal continuous positive airway pressure (nCPAP) admitted to our centre were eligible for the study. We retrospectively identified all episodes of ABCs. In ABCs where oxygen supply was increased, duration and severity of bradycardia (<80 bpm), SpO₂ ≤80%, SpO₂ ≥95% and their correlation were investigated.

RESULTS

In 56 infants, 257 ABCs occurred where oxygen supply was increased. SpO₂ ≥95% occurred after 79% (202/257) of the ABCs, duration of extra oxygen supply was longer in ABCs with SpO₂ ≥95% than without SpO₂ ≥95% (median (IQR) 20 (8-80) vs 2 (2-3) min; p<0.001)). The duration of SpO₂ ≥95% was longer than bradycardia and SpO₂ ≤80% (median (IQR) 13 (4-30) vs 1 (1-1) vs 2 (1-2) min; p<0.001). SpO₂ ≥95% lasted longer when infants were in ambient air than when oxygen was given before the ABC occurred (median (IQR)15 (5-38) min vs 6 (3-24) min; p<0.01).

CONCLUSIONS

In preterm infants supported with nCPAP in the neonatal intensive care unit (NICU), SpO₂ ≥95% frequently occurred when oxygen was increased for ABCs and lasted longer than the bradycardia and SpO₂ ≤80%.

Control of oxygenation during mechanical ventilation in the premature infant

Maintenance of oxygen saturation targets is a demanding and tedious task because of the frequency with which oxygenation changes, especially in small infants receiving prolonged respiratory support. It is clear that the achievement of oxygenation targets can be improved by a higher nurse-to-patient ratio and by intense staff training. Automated control systems can also improve target maintenance, and this is achieved mainly by reducing exposure to hyperoxemia. The long-term benefits and safety of this strategy are yet to be determined in clinical trials.

Maintaining optimal oxygen saturation in premature infants

INTRODUCTION

Advances in technology have resulted in increasing survival rates for premature infants. Oxygen therapy is commonly used in neonatal units as part of respiratory support. The number of premature infants in our institution surviving with severe (stage ≥3) retinopathy of prematurity (ROP) prompted a review of oxygen therapy as a contributing factor. Prolonged exposure to high concentrations of oxygen may cause irreversible damage to the eyes of very-low-birth-weight preterm infants and is a potential cause of blindness.

OBJECTIVE

We developed strategies to reduce incidence of severe ROP requiring laser surgery in premature infants.

METHODS

We studied 37 preterm infants who were born at a gestational age of <32 weeks, with a birth weight of <1500 g, receiving supplemental oxygen, and had been admitted to our neonatal intensive care unit. Infants received oxygen via mechanical ventilator, nasal continuous positive airway pressure (CPAP), or intranasal (I/N) and titration of oxygen was based on each infant's measured oxygen saturation (Spo(2)). For each infant, we monitored the Spo(2) trend, Spo(2) alarm limit, and the percentage of time that the alarm limit was set incorrectly. We implemented a Spo(2) targeting protocol and developed an algorithm for titrating fraction of inspired oxygen (Fio(2)).

RESULTS

After phase 1 of implementation, the percentage of time that Spo(2) readings were >95% was reduced to between 20% and 50%. However, our findings raised concern regarding the wide fluctuation of Spo(2) readings because of inconsistency in Fio(2) titration, which can contribute to deviation from the optimal target range. Accordingly, we developed an algorithm for titrating Fio(2) aimed at maintaining each infant's Spo(2) within the optimal target range. After phase 2 of implementation, the percentage of Spo(2) readings >95% was markedly reduced to between 0% and 15%. The incidence of infants with severe ROP requiring laser surgery decreased from 5 to 1.

CONCLUSIONS

A change in clinical practice aimed at maintaining oxygen within the target range to avoid a high Spo(2) was associated with a significant decrease in the incidence of both severe ROP and the need for laser surgery, thus reducing hospital costs and length of hospital stays for premature infants.

Nurses' compliance with alarm limits for pulse oximetry: qualitative study

OBJECTIVE

Monthly audits for the multicenter Canadian Oxygen Trial have shown that our neonatal team has consistently maintained study participants within the intended pulse oximetry alarm limits between 68 and 79% of the time during the first 3 days of life while infants were receiving supplemental oxygen. This good performance prompted us to explore our nurses' perceptions of what makes them compliant with alarm limits for pulse oximetry in preterm infants.

STUDY DESIGN

The local neonatal research nurse interviewed all 41 staff nurses in the neonatal intensive care unit at the University Children's Hospital in Tuebingen, Germany, for this qualitative study.

RESULT

Nurses identified education (22/41), prompt response to alarms (22/41), a favorable patient-to-staff ratio (18/41), root cause analysis at the bedside (15/41), and the high priority given to control of oxygen therapy in the department (14/41) as the five most important determinants of their good compliance.

CONCLUSION

These findings may be useful for other neonatal teams who struggle to improve their compliance with alarm limits for pulse oximetry.

Comprehensive Oxygen Management for the Prevention of Retinopathy of Prematurity: the pediatrix experience

Comprehensive oxygen management, focused on avoiding hyperoxia and repeated episodes of hypoxia-hyperoxia in very low birth weight infants, has been successfully used for the reduction of retinopathy of prematurity. Building on this experience, the Comprehensive Oxygen Management for the Prevention of Retinopathy of Prematurity quality improvement initiative was developed to facilitate the spread and refinement of these techniques. The initiative focused on staff education and evaluation and redesign of the processes and practices involving oxygen use. Monitoring of the effectiveness of the system changes was supported through audits of clinical practice changes, use of oxygen saturation trending data, and the incidence of retinopathy of prematurity.

Standardizing nasal cannula oxygen administration in the neonatal intensive care unit

OBJECTIVE

A multicycle, quality improvement method was used to standardize nasal cannula O2 administration and weaning in the NICU.

METHODS

A 2-armed nasal cannula standardized order form (nasal cannula for stable O2 arm and nasal cannula for stable flow arm) was developed after review of the literature, surveying of the practice of NICU physicians and nurse practitioners, and development of consensus among these providers. Outcomes were measured by tracking the distribution of protocol arm chosen, days on O2, weeks on nasal cannula, and disposition of infants who were supported by nasal cannula. Data were collected in an SPSS statistical data set.

RESULTS

Of the 90 infants evaluated, 12 were supported on the stable O2 arm and 53 on the stable flow arm for their entire nasal cannula course. Twenty-five infants switched between arms of support. Patients who were on the stable flow arm of the standard order set for their entire nasal cannula course experienced fewer O2 days but more days on nasal cannula. A subpopulation of infants were supported on nasal cannula flow 0.5 to 1.0 L, with fraction of inspired O2 of 21%. When data from the first 10 weeks of observation were compared with that of the second 10 weeks, the rate of discharge on O2 had decreased from 13 (30%) of 44 to 3 (7%) of 39.

CONCLUSIONS

The multiple steps of literature review, practice surveys, and consensus-building resulted in enthusiastic reception of the nasal cannula standardized order form. The 2-armed nasal cannula protocol forced caregivers to consider which method of support was most beneficial for each infant who was on nasal cannula and allowed a subpopulation of NICU patients to be supported with a lower fraction of inspired O2 than previously used in the NICU.