SpO2 Target Research Articles

Oxygenation Characteristics and Impact of Automated Closed-Loop Oxygen Administration in COVID-19 Patients: A Single ICU, Prospective, Observational Study

Background: An association between dyspnoea, hypoxaemia, and in-hospital mortality has been identified during the COVID-19 pandemic. The study aimed to depict the oxygenation characteristics of spontaneously breathing patients using automated closed-loop oxygen administration. Methods: This monocentre, prospective, observational study was derived from a data warehousing ICU project, Brest University Hospital, France. All spontaneously breathing patients were admitted for acute respiratory distress related to COVID-19 and required O2 administration. Automated O2 was administered using the FreeO2 system (Oxynov Inc., Québec, QC, Canada), which was set to maintain SpO2 between 90% and 94%. Continuous oximetry recordings were performed at 1 Hz. The primary outcome measure was the percentage of time spent within the SpO2 target. Secondary outcomes were outcome parameters, severity scores (EWSO2, qCSI), time within hyperoxaemia (SpO2 > 96%), hypoxaemia (SpO2 2 ≤ 85%) ranges. Oxygenation instability was considered while measuring the flow events (O2 increase > 2 L/min in 2 events. Findings: Fifty-nine patients were treated using FreeO2, of whom 21 after weaning from mechanical ventilation, 7 after high-flow nasal canula, and 31 as a first-line therapy. O2 was required for a median of 1.4 days. On treatment initiation, patients were hypoxaemic (estimated PaO2 /FIO2 = 221 [178–258]) and considered at a low to intermediate risk for deterioration (EWSO2 = 8.5 [7.9–10.4]; qCSI = 5.4 [4.4–6.2]). Time within range was high (86.3±10.6%; 90.0 [86.7–91.5]), with short time within hypoxaemia (9.4±9.7%; 6.1 [4.9–8.6]) and hyperoxaemia (2.8±6.2%; 0.7 [0.3–1.4]) ranges. Interpretation: The use of automated closed-loop oxygen administration is efficient and feasible, and it provides valuable information concerning the status of COVID-19 patients.Trial Registration: ReaSTOC study, ClinicalTrials.gov identifier: NCT02893462).Funding Statement: This study was funded by Brest University Hospital. No funding was received from Oxynov Inc. for this study, except in the form of technical expertise for clinical score implementation (qCSI and EWSO2) and interpretation.Declaration of Interests: Erwan L’HER and François LELLOUCHE are the inventors of the FreeO2 device and shareholders of Oxynov Inc., which produces the system. Erwan L’HER is a consultant for GE Healthcare, Smiths Medical, and Sedana. Quang-Thang NGUYEN is the research engineer from Oxynov Inc. that is responsible for the development of FreeO2. Victoire PATEAU is the research assistant from Brest ICU, and her salary is funded by Oxynov Inc. Severine ANSART has no conflict of interest.Ethics Approval Statement: Our local ethics committee (Comité d’Ethique du CHRU de Brest) approved the data collection and waived written informed consent according to French legislation.

Systemic Oxygen Utilization in Severe COVID-19 Respiratory Failure: A Case Series.

Management of hypoxemia in patients with severe COVID-19 respiratory failure is based on the guideline recommendations for specific SpO2 targets. However, limited data exist on systemic O2 utilization. The objective of this study was to examine systemic O2 utilization in a case series of patients with this disease. Between March 24, and April 9, 2020, 8 patients intubated for severe COVID-19 respiratory failure had near-simultaneous drawing of arterial blood gas (ABG), central venous blood gas (cVBG), and central venous oxygen saturation (ScvO2) at a mean of 6.1 days into hospitalization. Three patients were managed with indirect cardiac output (CO) monitoring by FloTrac sensor and Vigileo monitor (Edwards Lifesciences, Irvine, CA). The oxygen extraction index (OEI; SaO2-ScvO2/SaO2) and oxygen extraction fraction (OEF; CaO2-CvO2/CaO2 ≥ 100) were calculated. Values for hyperoxia (ScvO2 ≥ 90%), normoxia (ScvO2 71-89%), and hypoxia (ScvO2 ≤ 70%) were based on the literature. Mean values were calculated. The mean partial pressure of oxygen (PaO2) was 102 with a mean fraction of inspired O2 (FiO2) of 44%. One patient was hyperoxic with a reduced OEI (17%). Five patients were normoxic, but 2 had a reduced OEF (mean 15.9%). Two patients were hypoxic but had increased systemic O2 utilization based on OEF or OEI. In select patients with severe COVID-19 respiratory failure, O2 delivery (DO2) was found to exceed O2 utilization. SpO2 targets based on systemic O2 utilization may help in reducing oxygen toxicity, especially in the absence of anaerobic metabolism. Further data are needed on the prevalence of systemic O2 utilization in COVID-19. Garg RK, Kimbrough T, Lodhi W, DaSilva I. Systemic Oxygen Utilization in Severe COVID-19 Respiratory Failure: A Case Series. Indian J Crit Care Med 2021;25(2):215-218.

The Automatic Oxygen Saturation Control System by Adaptive Learning Controller for COVID-19 Patients

This paper proposes an adaptive learning control and monitoring of oxygen for patients with breathing complexities and respiratory diseases. By recording the oxygen saturation levels in real-time, this system uses an adaptive learning controller (ALC) to vary the oxygen delivered to the patient and maintains it in an optimum range. In the presented approach, the PID controller gain is tuned with the learning technique to provide improved response time and a proactive approach to oxygen control for the patient. A case study is performed by monitoring the time varying health vitals across different age groups to gain a better understanding of the relationship between these parameters for COVID-19 patients. This information is then used to improve the standard of care provided to patients and reducing the time to recovery. Results show that ALC controls the oxygen saturation within the target range of 90% to 94% SpO2, 77% and 80.1% of the time in patients of age groups 40-50 years old and 50-60 years old, respectively. It also had faster time to recovery to target SpO2 range when the concentration dropped rapidly or when the patient becomes hypoxic as compared to the manual control of the oxygen saturation by the healthcare staff.

Comparison of oxygenation and ventilation parameters between proseal laryngeal mask airway and endotracheal tube in patients undergoing laparoscopic surgeries: a prospective observational study

Introduction: Use of endotracheal tube (ETT) has many limitations. There is a need for an airway device with similar safety and good side effect profile. In this prospective observational study, the oxygenation and ventilation parameters between patients who were inserted Proseal laryngeal mask airway (PLMA) or ETT for laparoscopic surgeries were compared. Materials and Methods: After ethical committee approval, informed consent was obtained from sixty patients (thirty in each group) posted for elective laparoscopic surgery. Following induction of general anaesthesia and paralysis, PLMA or ETT was inserted and pressure control mode was used for ventilation. The following parameters were measured: a. Oxygen saturation and changes in FiO2 needed to ensure a target SpO2> 95%, EtCO2 and changes in respiratory rate and inspiratory pressure needed to ensure a target EtCO2 between 35-45 mmHg. b. Insertion characteristics of airway device and gastric tube, hemodynamic responses, incidence of complications. Statistical Analysis: Chi-square test was used to analyze qualitative data. Independent t test was used to assess quantitative variables. Repeated measures ANOVA was used to compare the outcome measures over time adjusted for duration of surgery and anaesthesia. P values Results: Both groups were comparable with respect to age, gender and weight. Oxygenation and ventilation parameters achieved with both ETT and PLMA were comparable and satisfactory. Haemodynamic parameters increased significantly in ETT group compared to PLMA group during airway insertion and removal. Also, postoperative sore throat was comparatively less in the PLMA group. Conclusion: Hence we conclude that PLMA may be considered as an alternative to ETT in airway management of patients undergoing laparoscopic surgeries with comparable oxygenation and ventilation parameters and improved side effect profile. Keywords: Endotracheal tube, Proseal laryngeal mask airway, Laryngoscopy, Pneumoperitoneum.

An audit of oxygen supplementation in a large tertiary hospital – we should treat oxygen as any other drug

ABSTRACT Objectives: To examine the current state of practice of oxygen (O2) supplementation in adults hospitalized in a tertiary hospital admitted to medical-surgical floors. Methods: We recorded: the proportion of patients on O2; their peripheral O2 saturation (SpO2); if the SpO2 was within, above, or below the target range; if patients had an order for O2 supplementation and a target SpO2 range. Results: Among 811 hospitalized patients, 153 (19%) were on supplemental O2. Forty-nine percent were in the recommended range, 55% above, and 1% below. All patients with COPD on O2 supplementation had a SpO2 of more than 92% exposing them to the risk of hypercarbia. Only 43% of patients on oxygen had an associated order and only 52% of patients with an O2 order had an order for a goal SpO2 range. Conclusions: Our results demonstrate widespread hyperoxia among hospitalized patients and that oxygen, a very common therapy, is being administered frequently without any written order. These findings highlight the opportunity to implement safe prescribing measures for O2, similar to other prescribed medications.

Acute oxygen therapy: a cross-sectional study of prescribing practices at an English hospital immediately before COVID-19 pandemic

ABSTRACT Background Approximately 14% of UK hospital in-patients receive supplemental oxygen therapy, only 57% have valid prescriptions. Oxygen must be optimally prescribed to ensure maximal therapeutic response whilst minimizing adverse outcomes (including fatality). This study investigates prescription compliance. Methods All adults admitted to medical wards (18 February to 3 March 2020) were included. Analyses present proportions, descriptive statistics, and hypothesis testing. Ethical approval was unnecessary for this audit. Results Of the 636 patients admitted, 66 (10%) were receiving oxygen therapy. Ages ranged from 34 to 100 years with 36 (54.5%) males and 30 (45.5%) females. The prescription was not documented in the oxygen section of the drug chart (n = 37, 56.1%, p = 0.389), nor did it have the physicians signature (n = 40, 60.6%, p = 0.110) nor date (n = 46, 69.7%, p = 0.002). Thirteen chronic obstructive pulmonary disease (COPD) patients (19.7%) were at risk of hypercapnic failure (p = 1.582x10−6). Target oxygen saturation (SpO2) range had been documented for 30 (45.5%) patients. A target SpO2 range of 88–92% was documented for 9 patients (13.6%), a 94–98% range documented for 11 patients (16.7%). All patients had an invalid prescription. Conclusion We present real-world practice in naturalistic settings, immediately before pandemic-lockdown. Enhanced compliance is advocated to reduce risks of harm and mortality.

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

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. Infants were studied on two consecutive days for 12hours 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. 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 >30seconds (P=.032) or >60seconds (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. Closed loop automated oxygen delivery resulted in fewer prolonged desaturations with more time spent in the targeted oxygen range.

Oxygen targets in the intensive care unit during mechanical ventilation for acute respiratory distress syndrome: a rapid review

Supplemental oxygen is frequently administered to patients with acute respiratory distress syndrome (ARDS), including ARDS secondary to viral illness such as coronavirus disease 19 (COVID-19). An up-to-date understanding of how best to target this therapy (e.g. arterial partial pressure of oxygen (PaO2) or peripheral oxygen saturation (SpO2) aim) in these patients is urgently required. To address how oxygen therapy should be targeted in adults with ARDS (particularly ARDS secondary to COVID-19 or other respiratory viruses) and requiring mechanical ventilation in an intensive care unit, and the impact oxygen therapy hason mortality, days ventilated,days of catecholamine use, requirement for renal replacement therapy, and quality of life. We searched the Cochrane COVID-19 Study Register, CENTRAL, MEDLINE, and Embase from inception to15 May 2020 for ongoing or completed randomized controlled trials (RCTs). Two review authors independently assessed all records in accordance with standard Cochrane methodology for study selection. We included RCTs comparing supplemental oxygen administration (i.e. different target PaO2 or SpO2 ranges)in adults with ARDS and receiving mechanical ventilation in an intensive care setting. We excluded studies exploring oxygen administration in patients with different underlying diagnoses or those receiving non-invasive ventilation, high-flow nasal oxygen, or oxygen via facemask. One review author performed data extraction, which a second review author checked. We assessed risk of bias in included studies using the Cochrane 'Risk of bias' tool. We used the GRADE approach to judge the certainty of the evidence for the following outcomes;mortality at longest follow-up,days ventilated,days of catecholamine use, and requirement for renal replacement therapy. We identified one completed RCT evaluating oxygen targets in patients with ARDS receiving mechanical ventilation in an intensive care setting. The study randomized 205 mechanically ventilated patients with ARDS to either conservative (PaO2 55 to 70 mmHg, or SpO2 88% to 92%) or liberal (PaO2 90 to 105 mmHg, or SpO2 ≥ 96%) oxygen therapy for seven days. Overall risk of bias was high (due to lack of blinding, small numbers of participants, and the trial stopping prematurely), and we assessed the certainty of the evidenceas very low. The available data suggested that mortality at 90 days may be higher in those participants receiving a lower oxygen target (odds ratio (OR) 1.83, 95% confidence interval (CI) 1.03 to 3.27). There was no evidence of a difference between the lower and higher target groups in mean number of days ventilated (14.0, 95% CI 10.0 to 18.0 versus 14.5, 95% CI 11.8 to 17.1); number of days of catecholamine use (8.0, 95% CI 5.5 to 10.5 versus 7.2, 95% CI 5.9 to 8.4); or participants receiving renal replacement therapy (13.7%, 95% CI 5.8% to 21.6% versus 12.0%, 95% CI 5.0% to 19.1%). Quality of life was not reported. We are very uncertain as to whether a higher or lower oxygen targetis more beneficial in patients with ARDS and receiving mechanical ventilation in an intensive care setting. We identified only one RCT with a total of 205 participants exploring this question, and rated the risk of bias as high and the certainty of the findings as very low. Further well-conducted studies are urgently needed to increase the certainty of the findings reported here. This review should be updated when more evidence is available.

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

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. 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%). 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. 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.

Big Data for Clinical Trials: Automated Collection of SpO2 for a Trial of Oxygen Targets during Mechanical Ventilation.

“Smoothing” is the phenomenon by which manually recorded vital signs are less likely to document values at the extremes compared to automated systems [1]. Intermittent manual recording of the peripheral oxygen saturation (SpO2) has the potential to inaccurately reflect patients’ true physiological states. Taenzer et al. observed that manually charted SpO2 values were, on average, 6.5 percentage points greater than SpO2 values collected by automated sampling [2]. Automated high-frequency SpO2 monitoring may more reliably quantify the incidence and severity of hypoxemia and hyperoxemia. Intensive Care Units (ICUs) have traditionally been more vigilant in preventing hypoxemia than hyperoxemia, and ICU patients frequently receive more supplemental oxygen than required to maintain normal values for SpO2 [3]. Hyperoxemia has been associated with worse patient outcomes in observational studies [4, 5], but randomized trials evaluating oxygen saturation targets for mechanically ventilated adults have reported conflicting results [6–9]. These trials have used intermittent recording of SpO2 by study personnel every 4 to 24 h to assess oxygenation. Automating data collection for SpO2 has the potential to facilitate the design, conduct, and analysis of pragmatic clinical trials examining SpO2 targets in mechanically ventilated ICU patients [10]. We developed a technique for automated extraction of large-volume data on SpO2 values for use in a randomized clinical trial. We aimed to quantify the completeness and density of SpO2 data among mechanically ventilated patients. We evaluated the reliability of automated extraction of SpO2 data from pulse oximetry using physician manual review of photoplethysmographic waveforms.

Evaluation of an enhanced pulse oximeter auditory display: a simulation study

BackgroundWe compared anaesthetists' ability to identify haemoglobin oxygen saturation (SpO2) levels using two auditory displays: one based on a standard pulse oximeter display (varying pitch plus alarm) and the other enhanced with additional sound properties (varying pitch plus tremolo and acoustic brightness) to differentiate SpO2 ranges. MethodsIn a counter-balanced crossover study in a simulator, 20 experienced anaesthetists supervised a junior colleague (an actor) managing two airway surgery scenarios: once while using the enhanced auditory display and once while using a standard auditory display. Participants were distracted with other tasks such as paperwork and workplace interruptions, but were required to identify when SpO2 transitioned between pre-set ranges (target, low, critical) and when other vital signs transitioned out of a target range. They also identified the range once a transition had occurred. Visual displays were available for all monitored vital signs, but the numerical value for SpO2 was excluded. ResultsParticipants were more accurate and faster at detecting transitions to and from the target SpO2 range when using the enhanced display (100.0%, 3.3 s) than when using the standard display plus alarm (73.2%, 27.4 s) (P<0.001 and P=0.004, respectively). They were also more accurate at identifying the SpO2 range once a transition had occurred when using the enhanced display (100.0%) than when using the standard display plus alarm (57.1%; P<0.001). ConclusionsThe enhanced auditory display helps anaesthetists judge SpO2 levels more effectively than current auditory displays and may facilitate ‘eyes-free’ monitoring.

Optimal Oxygen Targets in Term Lambs with Meconium Aspiration Syndrome and Pulmonary Hypertension.

Optimal oxygen saturation as measured by pulse oximetry (SpO2) in neonatal lung injury, such as meconium aspiration syndrome (MAS) and persistent pulmonary hypertension of newborn (PPHN), is not known. Our goal was to determine the SpO2 range in lambs with MAS and PPHN that results in the highest brain oxygen delivery (bDO2) and pulmonary blood flow (Qp) and the lowest pulmonary vascular resistance and oxidative stress. Meconium was instilled into endotracheal tubes in 25 near-term gestation lambs, and the umbilical cord was occluded to induce asphyxia and gasping, causing MAS and PPHN. Lambs were randomized into four groups and ventilated for 6 hours with fixed fraction of inspired oxygen (FiO2) = 1.0 irrespective of SpO2, and three groups had FiO2 titrated to keep preductal SpO2 between 85% and 89%, 90% and 94%, and 95% and 99%, respectively. Tissues were collected to measure nitric oxide synthase activity, 3-nitrotyrosine, and 8-isoprostanes. Throughout the 6-hour exposure period, lambs in the 95-99% SpO2 target group had the highest Qp, lowest pulmonary vascular resistance, and highest bDO2 but were exposed to higher FiO2 (0.5 ± 0.21 vs. 0.29 ± 0.17) with higher lung 3-nitrotyrosine (0.67 [interquartile range (IQR), 0.43-0.73] ng/mcg protein vs. 0.1 [IQR, 0.09-0.2] ng/mcg protein) and lower lung nitric oxide synthase activity (196 [IQR, 192-201] mMol nitrite/mg protein vs. 270 [IQR, 227-280] mMol nitrite/mg protein) compared with the 90-94% target group. Brain 3-nitrotyrosine was lower in the 85-89% target group, and brain/lung 8-isoprostane levels were not significantly different. In term lambs with MAS and PPHN, Qp and bDO2 through the first 6 hours are higher with target SpO2 in the 95-99% range. However, the 90-94% target range is associated with significantly lower FiO2 and lung oxidative stress. Clinical trials comparing the 90-94% versus the 95-99% SpO2 target range in term infants with PPHN are warranted.

Oxygen and Mortality in COVID-19 Pneumonia: A Comparative Analysis of Supplemental Oxygen Policies and Health Outcomes Across 26 Countries

Background: During the COVID-19 pandemic some countries have reduced access to supplemental oxygen by means of rationing or implementing conservative oxygen strategies, whereas other nations have maintained and even improved access to supplemental oxygen. Given hypoxia is the main cause of morbidity and mortality in COVID-19, we sought to analyse any potential effects on mortality of these divergent oxygen strategies. Methods: We examined the different oxygen policies across 29 nations in order to identify whether access to supplemental oxygen had any bearing on mortality in COVID-19. Specifically, we extracted the national recommendations for when to commence oxygen in patients with COVID-19, and through linear regression analysis compared these target oxygen values against national case fatality rates. Findings: Of the 26 nations included, 15 had employed conservative oxygen strategies to manage COVID-19 pneumonia. Of them, Belgium, France, USA, Canada, China, Germany, Mexico, Spain, Sweden and the UK guidelines advised commencing oxygen when oxygen saturations (SpO2) fell to 91% or less. Target SpO2 ranged from 92% to 95% in the other 16 nations. Linear regression analysis demonstrated a strong inverse correlation between target SpO2 and national case fatality rates ( rs = -0.622, p Interpretation: Our study highlights the marked disparity in oxygen provision for COVID-19 patients between the nations analysed, and indicates such disparity may represent a modifiable factor associated with mortality. Together with the growing body of evidence, our results suggest that limited access to supplemental oxygen, whether through rationing, conservative oxygen strategies or resource limitations, is likely to increase the mortality associated with COVID-19 pneumonia. Funding: There was no external funding for this study.Declaration of Interests: The authors declare no conflicts of interests.

Designing a Remote Closed-Loop Automatic Oxygen Control in Preterm Infants

Background: Different automated systems have been developed to improve the maintenance of target range of arterial oxygen saturation (SPO2) in premature infants with respiratory distress. Objectives: This study aimed to develop a remote closed-loop automatic oxygen control (RCLAC) as an efficient monitoring device. Then the means of the fraction of inspired oxygen (FIO2) and SPO2 by routine manual control (RMC) and RCLAC were compared. Methods: A developmental-descriptive study was carried out in an Iranian hospital (Tehran, Iran; 2015 - 2017). Twenty-two preterm infants with gestational age 24 - 28 weeks entered the study. A database was prepared based on pulse oximeter parameters. A Wi-Fi module was implemented to receive data from a pulse oximeter and send inputs to the user’s mobile. Vibrate alarm was implemented for high or low FIO2. After receiving notifications associated with an increase or decrease of FIO2 levels and user’s confirmation; the alterations were applied on the ventilator. Results: The mean FIO2 in the RMC system was significantly higher than the RCLAC system (98.1 ± 2.67 vs 79.5 ± 16.03; P = 0.0001). According to the results, when the SPO2 reached close to target SPO2 range and consequently FIO2 changed (decreased or increased based on target SPO2), heart rate showed a regular beating with a decrease in the numbers. Conclusions: Remote closed-loop automatic oxygen control system as a simple device could prevent preterm neonates from sustained hypo-hyperoxemic and arrhythmia episodes. Moreover, by using RCLAC, there was no need for continuous monitoring that may reduce the workload of NICU medical staff. Collecting reliable data and recording information in digital forms were also other benefits. Further studies with larger sample size are strongly suggested.

Rational supplemental oxygen therapy in COVID-19

Background: Hypoxemia often occurs in Coronavirus disease 2019 (COVID-19) patients. This condition requires adequate oxygen therapy to achieve oxygen saturation target. Objective: This review aims to explain the rational oxygen therapy in COVID-19. Materials and Methods: A literature search for studies on COVID-19 was performed using PubMed and Science Direct database. About 46 articles were identified. Twenty-five articles were considered suitable for review. The bibliographies of included studies were also searched for additional references. Results: Oxygen therapy involves conventional devices such as nasal cannulas, simple masks, reservoir masks, and venturi to advanced devices such as high-flow nasal cannulas. Initial therapy is given based on holistic assessment of the patient, followed by close monitoring. In emergency situations, airway management is required, and resuscitation is carried out with a saturation target of ≥94% while in stable patients, the SpO2 target is >90% in nonpregnant and ≥92%–95% in pregnant patients. Oxygen escalation might be needed during therapy without delaying intubation. Besides its intricate management algorithm, the rational management of oxygen therapy in COVID-19 also requires caution on the issue of each aerosol-generating device and transmission risk, especially for health-care workers. Conclusions: Rational management of oxygen therapy includes the provision of initial therapy, followed by proper monitoring and escalation without delaying intubation and also the considerations of the health-care workers' protection and the risk of transmission.

THE ADOPTION OF AUTOMATED FiO2 CONTROL INTO POLISH NICUS: 2012-2019

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.

Evaluation of hyperoxia-induced hypercapnia in obese patients after cardiac surgery: a randomized crossover comparison of conservative and liberal oxygen administration.

Recent studies on patients with stable obesity-hypoventilation syndrome have raised concerns about hyperoxia-induced hypercapnia in this population. This study aimed to evaluate whether a higher oxygen saturation target would increase arterial partial pressure of carbon dioxide (PaCO2) in obese patients after coronary artery bypass grafting surgery (CABG). Obese patients having CABG were recruited. With a randomized crossover design, we compared two oxygenation strategies for 30 min each, immediately after extubation:aperipheral oxygen saturation (SpO2)target of ≥ 95% achieved with manual oxygen titration (liberal) and a SpO2target of 90% achieved with FreeO2, an automated oxygen titration device (conservative). The main outcome was end-of-periodarterial PaCO2. Thirty patients were included. Mean (standard deviation [SD]) body mass index (BMI) was 34 (3) kg·m-2 and mean (SD) baseline partial pressure of carbon dioxide (PCO2) was 40.7 (3.1) mmHg. Mean (SD) end-of-period PaCO2 was 42.0 (5.4) mmHg in the conservative period, compared with 42.6 (4.6) mmHg in the liberal period [mean difference - 0.6 (95% confidence interval - 2.2 to 0.9) mmHg; P = 0.4]. Adjusted analysis for age, BMI, narcotics, and preoperative PaCO2 did not substantively change the results. Fourteen patients were retainers, showing an elevation in mean (SD) PaCO2 in the liberal period of 3.3 (4.1) mmHg. Eleven patients had the opposite response, with a mean (SD) end-of-period PaCO2 decrease of 1.8 (2.2) mmHg in the liberal period. Five patients had a neutral response. This study did not show a clinically important increase in PaCO2 associated with higher SpO2 values in this specific population of obese patients after CABG. Partial pressure of carbon dioxide increased with liberal oxygen administration in almost half of the patients, but no predictive factor was identified. www.clinicaltrials.gov (NCT02917668); registered 25 September, 2016.

Effects of closed-loop automatic control of the inspiratory fraction of oxygen (FiO2-C) on outcome of extremely preterm infants \u2013 study protocol of a randomized controlled parallel group multicenter trial for safety and efficacy

BackgroundMost extremely low gestational age neonates (ELGANS, postmenstrual age at birth (PMA) < 28 completed weeks) require supplemental oxygen and experience frequent intermittent hypoxemic and hyperoxemic episodes. Hypoxemic episodes and exposure to inadequately high concentrations of oxygen are associated with an increased risk of retinopathy of prematurity (ROP), chronic lung disease of prematurity (BPD), necrotizing enterocolitis (NEC), neurodevelopmental impairment (NDI), and death beyond 36 weeks PMA.Closed-loop automated control of the inspiratory fraction of oxygen (FiO2-C) reduces time outside the hemoglobin oxygen saturation (SpO2) target range, number and duration of hypo- and hyperoxemic episodes and caregivers’ workload. Effects on clinically important outcomes in ELGANs such as ROP, BPD, NEC, NDI and mortality have not yet been studied.MethodsAn outcome-assessor-blinded, randomized controlled, parallel-group trial was designed and powered to study the effect of FiO2-C (in addition to routine manual control (RMC) of FiO2), compared to RMC only, on death and severe complications related to hypoxemia and/or hyperoxemia. 2340 ELGANS with a GA of 23 + 0/7 to 27 + 6/7 weeks will be recruited in approximately 75 European tertiary care neonatal centers. Study participants are randomly assigned to RMC (control-group) or FiO2-C in addition to RMC (intervention-group). Central randomization is stratified for center, gender and PMA at birth (< 26 weeks and ≥ 26 weeks).FiO2-C is provided by commercially available and CE-marked ventilators with an FiO2-C algorithm intended for use in newborn infants. The primary outcome variable (composite of death, severe ROP, BPD or NEC) is assessed at 36 weeks PMA (or, in case of ROP, until complete vascularization of the retina, respectively). The co-primary outcome variable (composite outcome of death, language/cognitive delay, motor impairment, severe visual impairment or hearing impairment) is assessed at 24 months corrected age.DiscussionShort-term studies on FiO2-C showed improved time ELGANs spent within their assigned SpO2 target range, but effects of FiO2-C on clinical outcomes are yet unknown and will be addressed in the FiO2-C trial. This will ensure an appropriate assessment of safety and efficacy before FiO2-C may be implemented as standard therapy.Trial registrationThe study is registered at www.ClinicalTrials.gov: NCT03168516, May 30, 2017.

Drop that calculator! You can easily calculate the glucose infusion rate in your head, and should!

When an infant requires oxygen, it is well established that knowledge of the FiO2 at which the target SpO2 is achieved is essential. By analogy, it is clinically, physiologically, and diagnostically important to determine at what glucose infusion rate (GIR) one achieves target glucose levels in infants and children with hypoglycemia or dysregulated glucose levels. When counter-regulation is impaired or an infant is unwell, glucose utilization needs must be met from exogenous sources (1,2). Knowing the carbohydrate or glucose content and rate of administration of these sources, enteral or intravenous, allows calculation of the minimal GIR that meets utilization, and allows quantification of the endogenous production deficit. Calculating the GIR in all infants requiring intravenous glucose for hypoglycemia management should be a standard of care. The problem addressed in this Practical Tips is the difficulty of calculating GIR at the bedside with the commonly used formula: ... Where: GIR is in mg/kg/min, D is dextrose concentration in g/dL, Dir is dextrose infusion rate in mL/h, and w is weight in kg.

Impact of Conservative Versus Conventional Oxygenation on Outcomes of Patients in Intensive Care Units: A Systematic Review and Meta-analysis.

Background: There is mixed evidence in the superiority of conservative versus conventional approach to oxygen therapy among patients admitted into the intensive care unit (ICU). The purpose of this study was to determine if conservative versus conventional oxygenation results in a statistically significant difference in outcomes in ICU patients.Methods: A systematic review was registered with the International Prospective Register of Systematic Reviews (PROSPERO) and performed using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Inclusion criteria consisted of Level I-IV investigations of conservative versus conventional oxygenation among ICU patients. ICU mortality, 28-day mortality, in-hospital mortality, ICU length-of-stay, hospital length-of-stay, rate of new infections, and rate of new non-respiratory organ failure were compared using two-sample Z-tests using p-value less than 0.05.Results: Three thousand four hundred thirty-three articles were screened. Four articles were included in the analysis. Three hundred seventy-two patients under the conservative oxygenation arm (Minimum target SpO2: 88-94%) and 370 patients under the conventional oxygenation arm (Minimum target SpO2: 96-97%) were analyzed. ICU mortality (16.7 ± 9.5% vs. 22.7 ± 6.0%; P<0.01), 28-day mortality (34.6 ± 26.4% vs. 41.6 ± 14.6%; P=0.02), and in-hospital mortality (30.2 ± 22.5% vs. 37.7 ± 14.2%; P<0.01) were all significantly lower in the conservative oxygenation arm versus the conventional oxygenation arm, respectively. Rate of new non-respiratory organ failure was also significantly lower in the conservative oxygenation arm (20.0 ± 8.5% vs. 29.7 ± 11.7%; P<0.01).Conclusion: The authors conclude that conservative oxygenation therapy could result in significantly lower rates of ICU mortality, 28-day mortality, in-hospital mortality, and new-onset non-respiratory organ failure. Further randomized controlled studies that show clinical outcome improvement in multiple parameters may be worthwhile to assess the true efficacy of this practice.