BTS guideline for oxygen use in adults in healthcare and emergency settings

Association of ROX Index with Mechanical Ventilator Use in Sepsis Patients in the Emergency Department

Detecting sepsis patients who are at a high-risk of mechanical ventilation is important in emergency departments (ED). The respiratory rate oxygenation (ROX) index is the ratio of tissue oxygen saturation/fraction of inspired oxygen to the respiratory rate. This study aimed to investigate whether the ROX index could predict mechanical ventilator use in sepsis patients in an ED. This retrospective observational study included quick sequential organ failure assessment (qSOFA) ≥ 2 sepsis patients that presented to the ED between September 2019 and April 2020. The ROX and ROX-heart rate (HR) indices were significantly lower in patients with mechanical ventilator use within 24 h than in those without the use of a mechanical ventilator (4.0 [3.2–5.4] vs. 10.0 [5.9–15.2], p < 0.001 and 3.9 [2.7–5.8] vs. 10.1 [5.4–16.3], p < 0.001, respectively). The area under the receiver operating characteristic (ROC) curve of the ROX and ROX-HR indices were 0.854 and 0.816 (both p < 0.001). The ROX and ROX-HR indices were independently associated with mechanical ventilator use within 24 h (adjusted hazard ratio = 0.78, 95% CI: 0.68–0.90, p < 0.001 and adjusted hazard ratio = 0.87, 95% CI 0.79–0.96, p = 0.004, respectively). The 28-day mortality was higher in the low ROX and low ROX-HR groups. The ROX and ROX-HR indices were associated with mechanical ventilator use within 24 h in qSOFA ≥ 2 patients in the ED.

The long-term effects of lower versus higher oxygenation levels in adult ICU patients - protocol for a systematic review

BACKGROUND

Many organs can remain impaired after discharge from the intensive care unit (ICU) leading to temporal or permanent dysfunctions. Long-term impairments may be affected by supplemental oxygen, a common treatment in ICU, having both potential beneficial and harmful long-lasting effects. This systematic review aims to assess the long-term outcomes of lower versus higher oxygen supplementation and/or oxygenation levels in adults admitted to ICU.

METHODS

We will include trials differentiating between a lower and a higher oxygen supplementation or a lower and a higher oxygenation strategy in adults admitted to the ICU. We will search major electronic databases and trial registers for randomised clinical trials. Two authors will independently screen and select references for inclusion using Covidence and predefined data will be extracted. The methodological quality and risk of bias of included trials will be evaluated using the Cochrane Risk of Bias tool 2. Meta-analysis will be performed if two or more trials with comparable outcome measures will be included. Otherwise, a narrative description of the trials' results will be presented instead. To assess the certainty of evidence, we will create a 'Summary of findings' table containing all prespecified outcomes using the GRADE system. The protocol is submitted on the PROSPERO database (ID 223630).

CONCLUSION

No systematic reviews on the impact of oxygen treatment in the ICU on long-term outcomes, other than mortality and quality of life, have been reported yet. This systematic review will provide an overview of the current evidence and will help future research in the field.

[Chronic respiratory failure correction in cicatricial laryngeal and tracheal stenosis using helium-oxygen mixture]

The article provides a review of the literature on the development of chronic respiratory failure in patients with chronic cicatricial stenosis of the larynx and cervical trachea. The authors provide data on the etiology, pathogenetic features of the course of cicatricial stenosis of the larynx and trachea, the reasons for the development of chronic respiratory failure, the effect of hypoxemia on general metabolic processes in the body and on regeneration processes, as well as on methods of their correction and improvement of the postoperative period. The methods of respiratory impact on chronic respiratory failure in these patients are considered, based on the experience of a number of researchers and technical advances in recent years.

German S3 Guideline: Oxygen Therapy in the Acute Care of Adult Patients

BACKGROUND

Oxygen (O2) is a drug with specific biochemical and physiological properties, a range of effective doses and may have side effects. In 2015, 14% of over 55,000 hospital patients in the UK were using oxygen. 42% of patients received this supplemental oxygen without a valid prescription. Health care professionals are frequently uncertain about the relevance of hypoxemia and have low awareness about the risks of hyperoxemia. Numerous randomized controlled trials about targets of oxygen therapy have been published in recent years. A national guideline is urgently needed.

METHODS

A national S3 guideline was developed and published within the Program for National Disease Management Guidelines (AWMF) with participation of 10 medical associations. A literature search was performed until February 1, 2021, to answer 10 key questions. The Oxford Centre for Evidence-Based Medicine (CEBM) System ("The Oxford 2011 Levels of Evidence") was used to classify types of studies in terms of validity. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used for assessing the quality of evidence and for grading guideline recommendation, and a formal consensus-building process was performed.

RESULTS

The guideline includes 34 evidence-based recommendations about indications, prescription, monitoring and discontinuation of oxygen therapy in acute care. The main indication for O2 therapy is hypoxemia. In acute care both hypoxemia and hyperoxemia should be avoided. Hyperoxemia also seems to be associated with increased mortality, especially in patients with hypercapnia. The guideline provides recommended target oxygen saturation for acute medicine without differentiating between diagnoses. Target ranges for oxygen saturation are based depending on ventilation status risk for hypercapnia. The guideline provides an overview of available oxygen delivery systems and includes recommendations for their selection based on patient safety and comfort.

CONCLUSION

This is the first national guideline on the use of oxygen in acute care. It addresses health care professionals using oxygen in acute out-of-hospital and in-hospital settings.

Dangers of hyperoxia

Oxygen (O2) toxicity remains a concern, particularly to the lung. This is mainly related to excessive production of reactive oxygen species (ROS). Supplemental O2, i.e. inspiratory O2 concentrations (FIO2) > 0.21 may cause hyperoxaemia (i.e. arterial (a) PO2 > 100 mmHg) and, subsequently, hyperoxia (increased tissue O2 concentration), thereby enhancing ROS formation. Here, we review the pathophysiology of O2 toxicity and the potential harms of supplemental O2 in various ICU conditions. The current evidence base suggests that PaO2 > 300 mmHg (40 kPa) should be avoided, but it remains uncertain whether there is an "optimal level" which may vary for given clinical conditions. Since even moderately supra-physiological PaO2 may be associated with deleterious side effects, it seems advisable at present to titrate O2 to maintain PaO2 within the normal range, avoiding both hypoxaemia and excess hyperoxaemia.

Management of COVID-19-Associated Acute Respiratory Failure with Alternatives to Invasive Mechanical Ventilation: High-Flow Oxygen, Continuous Positive Airway Pressure, and Noninvasive Ventilation

Patients admitted to hospital with coronavirus disease 2019 (COVID-19) may develop acute respiratory failure (ARF) with compromised gas exchange. These patients require oxygen and possibly ventilatory support, which can be delivered via different devices. Initially, oxygen therapy will often be administered through a conventional binasal oxygen catheter or air-entrainment mask. However, when higher rates of oxygen flow are needed, patients are often stepped up to high-flow nasal cannula oxygen therapy (HFNC), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or invasive mechanical ventilation (IMV). BiPAP, CPAP, and HFNC may be beneficial alternatives to IMV for COVID-19-associated ARF. Current evidence suggests that when nasal catheter oxygen therapy is insufficient for adequate oxygenation of patients with COVID-19-associated ARF, CPAP should be provided for prolonged periods. Subsequent escalation to IMV may be implemented if necessary.

Management of COVID-19-Associated Acute Respiratory Failure with Alternatives to Invasive Mechanical Ventilation: High-Flow Oxygen, Continuous Positive Airway Pressure, and Noninvasive Ventilation

Patients admitted to hospital with coronavirus disease 2019 (COVID-19) may develop acute respiratory failure (ARF) with compromised gas exchange. These patients require oxygen and possibly ventilatory support, which can be delivered via different devices. Initially, oxygen therapy will often be administered through a conventional binasal oxygen catheter or air-entrainment mask. However, when higher rates of oxygen flow are needed, patients are often stepped up to high-flow nasal cannula oxygen therapy (HFNC), continuous positive airway pressure (CPAP), bilevel positive airway pressure (BiPAP), or invasive mechanical ventilation (IMV). BiPAP, CPAP, and HFNC may be beneficial alternatives to IMV for COVID-19-associated ARF. Current evidence suggests that when nasal catheter oxygen therapy is insufficient for adequate oxygenation of patients with COVID-19-associated ARF, CPAP should be provided for prolonged periods. Subsequent escalation to IMV may be implemented if necessary.

Hypoxia driven opioid targeted automated device for overdose rescue

Opioid use disorder has been designated a worsening epidemic with over 100,000 deaths due to opioid overdoses recorded in 2021 alone. Unintentional deaths due to opioid overdoses have continued to rise inexorably. While opioid overdose antidotes such as naloxone, and nalmefene are available, these must be administered within a critical time window to be effective. Unfortunately, opioid-overdoses may occur in the absence of antidote, or may be unwitnessed, and the rapid onset of cognitive impairment and unconsciousness, which frequently accompany an overdose may render self-administration of an antidote impossible. Thus, many lives are lost because: (1) an opioid overdose is not anticipated (i.e., monitored/detected), and (2) antidote is either not present, and/or not administered within the critical frame of effectiveness. Currently lacking is a non-invasive means of automatically detecting, reporting, and treating such overdoses. To address this problem, we have designed a wearable, on-demand system that comprises a safe, compact, non-invasive device which can monitor, and effectively deliver an antidote without human intervention, and report the opioid overdose event. A novel feature of our device is a needle-stow chamber that stores needles in a sterile state and inserts needles into tissue only when drug delivery is needed. The system uses a microcontroller which continuously monitors respiratory status as assessed by reflex pulse oximetry. When the oximeter detects the wearer’s percentage of hemoglobin saturated with oxygen to be less than or equal to 90%, which is an indication of impending respiratory failure in otherwise healthy individuals, the microcontroller initiates a sequence of events that simultaneously results in the subcutaneous administration of opioid antidote, nalmefene, and transmission of a GPS-trackable 911 alert. The device is compact (4 × 3 × 3 cm), adhesively attaches to the skin, and can be conveniently worn on the arm. Furthermore, this device permits a centralized remotely accessible system for effective institutional, large-scale intervention. Most importantly, this device has the potential for saving lives that are currently being lost to an alarmingly increasing epidemic.

Increasing oxygen prescribing during the COVID-19 pandemic

Valid oxygen prescriptions for hospital inpatients have been a long-standing problem and have been described extensively in BMJ Open Quality with numerous quality improvement projects (QIPs) with the aim of improving compliance with oxygen prescribing.The British Thoracic Society recommends that all inpatients should have oxygen target saturation set on admission: this is motivated by risks of both undertreatment and overtreatment with oxygen. The discrepancy between the recommendation and the reality produced a number of interventions studied in QIPs over the past years, all aiming at bringing the local ward teams closer to the target. This has become even more important during the COVID-19 pandemic, where non-standard oxygen saturation targets and oxygen scarcity led hospital systems to rethink their internal guidelines on the subject.We propose three novel interventions to improve compliance: a remote, personally directed email communication to a ward pharmacist, a similar communication to ward nurses, and a remote, personally directed WhatsApp communication to junior ward doctors. We undertake a QIP which compares novel interventions developed in-house with the most successful interventions from oxygen prescribing initiatives that have previously been published by BMJ Open Quality The main outcome measure was the proportion of patients with valid oxygen prescription on a ward.The series of novel interventions in three plan, do study, act cycles led to improvement in the outcome measure from 0% at baseline to 70% at the end of the QIP. The successful interventions from previous QIPs were ran in parallel on a similar ward and achieved improvement from 17.9% at baseline to 55.6% at the end of the QIP.This QIP demonstrates adapted interventions performed in context of social distancing aimed at members of multidisciplinary team which achieve superiority in increasing proportion of patients with a valid oxygen prescription, when compared with previously described methods from BMJ Open Quality.

Assessing and managing post-operative haemorrhage and haemorrhagic shock

Improved surgical outcomes have been achieved as a result of preoperative risk assessments and developments in surgical and anaesthetic techniques. However, post-operative haemorrhage remains a life-threatening complication requiring swift recognition and management. This article explores the compensatory mechanisms the body employs during haemorrhage and how these may present as altered observations that can aid early recognition. It also describes the rapid assessment of patients using the ABCDE (airway, breathing, circulation, disability, exposure) approach and outlines the management interventions used to halt the bleeding and restore intravascular volume.

Respiratory assessment: undertaking a physical examination of the chest in adults

Nurses frequently encounter patients in respiratory distress or with respiratory complications, whether from acute disease or a long-term condition. A physical examination of the chest should be conducted as part of a comprehensive respiratory assessment of the patient, and should follow a systematic approach that includes inspection, palpation, percussion and auscultation. Nurses undertaking these hands-on components of respiratory assessments need to have adequate knowledge of the procedures involved, as well as practical skills that need to be practised under supervision. This article outlines how to undertake a physical examination of the chest in adults.

Time for change in practice of in-patient oxygen therapy: a period-limited, multidimensional approach to improve oxygen prescription compliance: quality improvement project at Hamad General Hospital, Qatar

Prescription of oxygen therapy has traditionally poor compliance across the globe and mostly given to patients on verbal orders leading to under or overuse. The British Thoracic Society (BTS) guidelines (2017) recommend that oxygen therapy must be prescribed. Our study aimed to assess the prescription practice of oxygen therapy for patients admitted to acute medical assessment unit and general medical wards at Hamad General Hospital, Qatar and to achieve 80% compliance of valid oxygen therapy prescription implementing the quality improvement model against the BTS guidelines.The prescription practice of oxygen therapy was audited between April 2019 and August 2019. Using a Plan, Do, Study, Act (PDSA) model of improvement and multiple interventions was performed in the eight PDSA cycles, including (1) educational sessions for residents/fellows/nurses, (2) introduction of electronic prescription, (3) emails, posters/flyers, (4) nurse-led reminders and (5) re-enforced teaching for new residents. Data were then collected using a questionnaire assessing electronic prescriptions and documentation. Our baseline study regarding oxygen therapy showed limited awareness of BTS guidelines regarding the documentation of initiation and further adjustment of oxygen therapy. There was a lack of compliance with oxygen prescription; none of the patients had a valid prescription on our computer-based prescription (Cerner). The duration, target range and indications of Oxygen therapy were documented in 25% (18/72), 45.8% (33/72) and 42% (30/72) patients, respectively. Oxygen was initiated by communication order only. In a total of 16 weeks period, the repeated PDSA cycles showed significant improvement in safe oxygen prescription practices. Following intervention, oxygen electronic prescription, documentation of indications for oxygen therapy, target oxygen saturation and wean-off plan improved to 93%, 85%, 86 % and 80 %, respectively.We concluded that poor compliance to oxygen therapy Orders is a universal issue, which can be successfully managed using small-scale PDSA cycles to ensure sustained improvement through multidimensional interventions, continuous reinforcement and frequent reassessments.

Protocol and statistical analysis plan for the Pragmatic Investigation of optimaL Oxygen Targets (PILOT) clinical trial

INTRODUCTION

Mechanical ventilation of intensive care unit (ICU) patients universally involves titration of the fraction of inspired oxygen to maintain arterial oxygen saturation (SpO2). However, the optimal SpO2 target remains unknown.

METHODS AND ANALYSIS

The Pragmatic Investigation of optimaL Oxygen Targets (PILOT) trial is a prospective, unblinded, pragmatic, cluster-crossover trial being conducted in the emergency department (ED) and medical ICU at Vanderbilt University Medical Center in Nashville, Tennessee, USA. PILOT compares use of a lower SpO2 target (target 90% and goal range: 88%-92%), an intermediate SpO2 target (target 94% and goal range: 92%-96%) and a higher SpO2 target (target 98% and goal range: 96%-100%). The study units are assigned to a single SpO2 target (cluster-level allocation) for each 2-month study block, and the assigned SpO2 target switches every 2 months in a randomly generated sequence (cluster-level crossover). The primary outcome is ventilator-free days (VFDs) to study day 28, defined as the number of days alive and free of invasive mechanical ventilation from the final receipt of invasive mechanical ventilation through 28 days after enrolment.

ETHICS AND DISSEMINATION

The trial was approved by the Vanderbilt Institutional Review Board. The results will be submitted for publication in a peer-reviewed journal and presented at one or more scientific conferences.

TRIAL REGISTRATION NUMBER

The trial protocol was registered with ClinicalTrials.gov on 25 May 2018 prior to initiation of patient enrolment (ClinicalTrials.gov identifier: NCT03537937).

Determination of oxygen saturation compared to a prescribed target range using continuous pulse oximetry in acutely unwell medical patients

BACKGROUND

Both inadequate and excessive administration of oxygen to acutely unwell patients results in risk of harm. Guidelines recommend titration of oxygen to achieve a target oxygen saturation (SpO2) range. Information regarding whether this is being achieved is limited.

METHODS

In this two-centre non-interventional study we used continuous pulse oximetry in acutely unwell medical patients over a 24-h period to determine the proportion of time spent with SpO2 within the prescribed target range and whether this is influenced by the target range, age, care in a high-dependency area and the number of oxygen adjustments.

RESULTS

Eighty participants were included in the analysis. The mean (SD) proportion of time spent in target range was 55.6% (23.6), this was lower in those with a reduced hypercapnic target range (88-92% or below) compared to those with a range of 92-96%; difference - 13.1% (95% CI - 3.0 to - 23.2), P = 0.012. The proportion of time spent above range was 16.2% (22.9); this was higher in those with a reduced hypercapnic range; difference 21.6% (31.4 to 12), P < 0.001. The proportion of time below range was 28.4% (25.2); there was no difference between target ranges. The proportion of time spent in range was higher for those in a high dependency area in the multivariate model; difference 15.5% (95% CI 2.3 to 28.7), P = 0.02.

CONCLUSIONS

Medical patients receiving oxygen in a ward setting spend significant periods of time with SpO2 both above and below the prescribed target range while receiving oxygen therapy.

The Roth score as a triage tool for detecting hypoxaemia in general practice: a diagnostic validation study in patients with possible COVID-19

AIM

To validate the Roth score as a triage tool for detecting hypoxaemia.

BACKGROUNDS

The virtual assessment of patients has become increasingly important during the corona virus disease (COVID-19) pandemic, but has limitations as to the evaluation of deteriorating respiratory function. This study presents data on the validity of the Roth score as a triage tool for detecting hypoxaemia remotely in potential COVID-19 patients in general practice.

METHODS

This cross-sectional validation study was conducted in Dutch general practice. Patients aged ≥18 with suspected or confirmed COVID-19 were asked to rapidly count from 1 to 30 in a single breath. The Roth score involves the highest number counted during exhalation (counting number) and the time taken to reach the maximal count (counting time).Outcome measures were (1) the correlation between both Roth score measurements and simultaneous pulse oximetry (SpO2) on room air and (2) discrimination (c-statistic), sensitivity, specificity and predictive values of the Roth score for detecting hypoxaemia (SpO2 < 95%).

FINDINGS

A total of 33 physicians enrolled 105 patients (52.4% female, mean age of 52.6 ± 20.4 years). A positive correlation was found between counting number and SpO2 (rs = 0.44, P < 0.001), whereas only a weak correlation was found between counting time and SpO2 (rs = 0.15, P = 0.14). Discrimination for hypoxaemia was higher for counting number [c-statistic 0.91 (95% CI: 0.85-0.96)] than for counting time [c-statistic 0.77 (95% CI: 0.62-0.93)]. Optimal diagnostic performance was found at a counting number of 20, with a sensitivity of 93.3% (95% CI: 68.1-99.8) and a specificity of 77.8% (95% CI: 67.8-85.9). A counting time of 7 s showed the best sensitivity of 85.7% (95% CI: 57.2-98.2) and specificity of 81.1% (95% CI: 71.5-88.6).

CONCLUSIONS

A Roth score, with an optimal counting number cut-off value of 20, maybe of added value for signalling hypoxaemia in general practice. Further external validation is warranted before recommending integration in telephone triage.

2021 Guideline for the Management of COPD Exacerbations: Emergency Medicine Association of Turkey (EMAT) / Turkish Thoracic Society (TTS) Clinical Practice Guideline Task Force

Chronic obstructive pulmonary disease (COPD) is an important public health problem that manifests with exacerbations and causes serious mortality and morbidity in both developed and developing countries. COPD exacerbations usually present to emergency departments, where these patients are diagnosed and treated. Therefore, the Emergency Medicine Association of Turkey and the Turkish Thoracic Society jointly wanted to implement a guideline that evaluates the management of COPD exacerbations according to the current literature and provides evidence-based recommendations. In the management of COPD exacerbations, we aim to support the decision-making process of clinicians dealing with these patients in the emergency setting.

Impact of Oxygen Concentration Delivered via Nasal Cannula on Different Lung Conditions: A Bench Study

BACKGROUND

Measuring the fraction of inspired oxygen (FiO2) is challenging in spontaneously breathing patients with impaired respiratory mechanics during low-flow nasal cannula. Our study investigates the FiO2 with varied tidal volume (VT) and respiratory rate (RR) among different lung mechanics and provides equations to estimate the FiO2.

METHODS

Two training and test lungs were used in this study, and the three lung mechanics (normal (R5/C60), restrictive (R20/C80), obstructive (R5/C40)) were designed. Spontaneous breathing with VT (300, 500, and 700 mL) and RR (10, 20, and 30 breaths/min) was simulated. The flow rate of the nasal cannula was set to 1, 3, and 5 L per minute (LPM), and the FiO2 was measured at the carina.

RESULTS

The lowest and highest FiO2 were evident during high (700 mL) and low VT (300 mL), respectively, among normal, restrictive, and obstructive lung models. As RR increases, this decreases the FiO2. However, we found that VT and oxygen flow rate are the principal factors influencing measured FiO2 by multiple linear regression analysis.

CONCLUSIONS

Our data suggest that the actual FiO2 is never as high in spontaneously breathing patients as that estimated. VT and oxygen flow rate had a substantial impact on the FiO2.

Liberal or conservative oxygen therapy for ventilated patients in the ICU: a meta-analysis of randomized controlled trials

Background

The acknowledgment that conservative oxygen therapy (COT) was related to better prognosis in the intensive care unit (ICU) was challenged recently. We conducted an updated meta-analysis aimed to determine whether liberal oxygen therapy (LOT) or COT is associated with better improve clinical outcomes.

Methods

We systematically searched the electronic databases (PubMed, Web of Science and Embase) up to May 2021 for randomized controlled trials (RCTs). The primary outcome was the mortality of the final follow-up time and secondary outcomes were ICU mortality, the ICU length of stay and the number of ventilator-free days.

Results

A total of 7 RCTs were included, with 2166 patients admitted to the ICU. There was no significant difference in the primary outcome between the LOT and COT. Additionally, LOT could not significantly increase ICU mortality and the ICU length of stay compared with COT.

Conclusions

The present study showed that COT was not significantly superior to LOT in clinical outcomes. Therefore, additional high-quality studies with novel designs are required to further elucidate this controversy.

Association Between Oxygen Partial Pressure Trajectories and Short-Term Outcomes in Patients With Hemorrhagic Brain Injury

Objectives: Arterial hyperoxia is reportedly a risk factor for poor outcomes in patients with hemorrhagic brain injury (HBI). However, most previous studies have only evaluated the effects of hyperoxia using static oxygen partial pressure (PaO2) values. This study aimed to investigate the association between overall dynamic oxygenation status and HBI outcomes, using longitudinal PaO2 data. Methods: Data were extracted from the Medical Information Mart for Intensive Care III database. Longitudinal PaO2 data obtained within 72 h of admission to an intensive care unit were analyzed, using a group-based trajectory approach. In-hospital mortality was used as the primary outcomes. Multivariable logistic models were used to explore the association between PaO2 trajectory and outcomes. Results: Data of 2,028 patients with HBI were analyzed. Three PaO2 trajectory types were identified: Traj-1 (mild hyperoxia), Traj-2 (transient severe hyperoxia), and Traj-3 (persistent severe hyperoxia). The initial and maximum PaO2 of patients with Traj-2 and Traj-3 were similar and significantly higher than those of patients with Traj-1. However, PaO2 in patients with Traj-2 decreased more rapidly than in patients with Traj-3. The crude in-hospital mortality was the lowest for patients with Traj-1 and highest for patients with Traj-3 (365/1,303, 209/640, and 43/85 for Traj-1, Traj-2, and Traj-3, respectively; p < 0.001), and the mean Glasgow Coma Scale score at discharge (GCSdis) was highest for patients with Traj-1 and lowest in patients with Traj-3 (13 [7-15], 11 [6-15], and 7 [3-14] for Traj-1, Traj-2, and Traj-3, respectively; p < 0.001). The multivariable model revealed that the risk of death was higher in patients with Traj-3 than in patients with Traj-1 (odds ratio [OR]: 3.3, 95% confidence interval [CI]: 1.9-5.8) but similar for patients with Traj-1 and Traj-2. Similarly, the logistic analysis indicated the worst neurological outcomes in patients with Traj-3 (OR: 3.6, 95% CI: 2.0-6.4, relative to Traj-1), but similar neurological outcomes for patients in Traj-1 and Traj-2. Conclusion: Persistent, but not transient severe arterial hyperoxia, was associated with poor outcome in patients with HBI.

Oxygen therapy for critically Ill and post-operative patients

Nearly all patients receiving treatment in a peri-operative or intensive care setting receive supplemental oxygen therapy. It is biologically plausible that the dose of oxygen used might affect important patient outcomes. Most peri-operative research has focussed on oxygen regimens that target higher than normal blood oxygen levels. Whereas, intensive care research has mostly focussed on conservative oxygen regimens which assiduously avoid exposure to higher than normal blood oxygen levels. While such conservative oxygen therapy is preferred for spontaneously breathing patients with chronic obstructive pulmonary disease, the optimal oxygen regimen in other patient groups is not clear. Some data suggest that conservative oxygen therapy might be preferred for patients with hypoxic ischaemic encephalopathy. However, unless oxygen supplies are constrained, routinely aggressively down-titrating oxygen in either the peri-operative or intensive care setting is not necessary based on available data. Targeting higher than normal levels of oxygen might reduce surgical site infections in the perioperative setting and/or improve outcomes for intensive care patients with sepsis but further research is required and available data are not sufficiently strong to warrant routine implementation of such oxygen strategies.

Long COVID and breathlessness: an overview

This article offers a review of what is known so far about post-acute covid-19 and the underlying pathophysiology related to this condition. The main focus will be on the respiratory symptoms. It will then explore how community nurses can monitor and support patients with symptoms of breathlessness with a supporting discussion of the current recommendations for the management and treatment of patients presenting with symptoms of breathlessness. Palliation of symptoms will be highlighted but managing the supportive care needs for patients affected by COVID-19 and nearing the end of life is outside the scope of this article.

[German S3 Guideline - Oxygen Therapy in the Acute Care of Adult Patients]

BACKGROUND

 Oxygen (O₂) is a drug with specific biochemical and physiologic properties, a range of effective doses and may have side effects. In 2015, 14 % of over 55 000 hospital patients in the UK were using oxygen. 42 % of patients received this supplemental oxygen without a valid prescription. Healthcare professionals are frequently uncertain about the relevance of hypoxemia and have low awareness about the risks of hyperoxemia. Numerous randomized controlled trials about targets of oxygen therapy have been published in recent years. A national guideline is urgently needed.

METHODS

 A S3-guideline was developed and published within the Program for National Disease Management Guidelines (AWMF) with participation of 10 medical associations. Literature search was performed until Feb 1st 2021 to answer 10 key questions. The Oxford Centre for Evidence-Based Medicine (CEBM) System ("The Oxford 2011 Levels of Evidence") was used to classify types of studies in terms of validity. Grading of Recommendations, Assessment, Development and Evaluation (GRADE) was used and for assessing the quality of evidence and for grading guideline recommendation and a formal consensus-building process was performed.

RESULTS

 The guideline includes 34 evidence-based recommendations about indications, prescription, monitoring and discontinuation of oxygen therapy in acute care. The main indication for O₂ therapy is hypoxemia. In acute care both hypoxemia and hyperoxemia should be avoided. Hyperoxemia also seems to be associated with increased mortality, especially in patients with hypercapnia. The guideline provides recommended target oxygen saturation for acute medicine without differentiating between diagnoses. Target ranges for oxygen saturation are depending on ventilation status risk for hypercapnia. The guideline provides an overview of available oxygen delivery systems and includes recommendations for their selection based on patient safety and comfort.

CONCLUSION

 This is the first national guideline on the use of oxygen in acute care. It addresses healthcare professionals using oxygen in acute out-of-hospital and in-hospital settings. The guideline will be valid for 3 years until June 30, 2024.

Capillary Blood Gas Predicts Risk of Intensive Care in Children with Bronchiolitis

Background: Bronchiolitis may result in respiratory failure diagnosed with arterial blood gas (ABG). ABG is not routinely performed in general paediatric wards but is closely reflected by capillary blood gas (CBG). We sought to assess the usefulness of CBG results in prediction of intensive care unit (ICU) transfer, antibiotic treatment, and length of stay in children hospitalized due to bronchiolitis. Methods: The optimal cutoff values were estimated with an ROC analysis, while a multiple regression model calculated the odds of an ICU transfer, prolonged hospitalization, and antibiotic treatment related with hypercapnia (pCO₂ ≥ 45 mmHg) and acidosis (pH ≤ 7.35). The correlation between the CBG (pH, pCO₂, and SatO₂) and the clinical/laboratory parameters (breath rate, heart rate, pulse oximetry, white blood cells, CRP, and procalcitonin) was calculated. Results: The CBG was performed in 485 children aged 8 days–22 months (median 2 months). The pCO₂ was significantly higher in ICU transferred patients (median 44.8 mmHg vs. 36.2 mmHg, p < 0.01), and showed AUC = 0.773, (95% CI: 0.638–0.907, p < 0.01) for ICU transfer (67% sensitivity, 82% specificity, 10.8% positive and 98.7% negative predictive value at cutoff 41.8 mmHg). Hypercapnia (OR = 6.63, 95% CI: 2.15–20.46, p < 0.01) and acidosis (OR = 5.01, 95% CI: 1.26–19.9, p = 0.022) predicted the ICU transfer independently. The CBG parameters were not related to prolonged hospitalization or antibiotic treatment, and showed only a weak and clinically irrelevant correlation with other laboratory and clinical parameters. Conclusions: Acidosis and hypercapnia indicate patients at risk of an ICU transfer, and the pCO₂ levels (including values lower than hypercapnia) seem to be a promising marker in ICU risk assessment.

Placement of finger oximeter on the ear: comparison with oxygen saturation values taken from the finger

Pulse oximetry is widely used to assess oxygen saturation (SpO₂) in order to guide patient care and monitor the response to treatment. However, inappropriate oximeter probe placement has been shown to affect the measured oximetry values in healthy and normoxic outpatients. This study evaluated how treatment decisions might be impacted by SpO₂ values obtained using a finger probe placed on the pinna of the ear in a cohort of 46 patients receiving non-invasive ventilation compared with values obtained from a probe on the finger and the results of arterial blood gas (ABG) (SaO₂) analysis. Bland-Altman analysis was performed to evaluate agreement between the methods. Finger probe saturation was not statistically different from SaO₂, with a mean difference of -0.66% (P>0.05). Saturation from the ear was significantly different (-4.29%; P<0.001). Subgroup analysis in hypoxic patients (SaO₂<90%) showed a significant difference between ABG SaO₂, and finger and ear SpO₂. The study provides evidence that placement of a finger probe on the ear is unsafe clinical practice, potentially leading to patient mismanagement.

Automatic versus manual oxygen titration using a novel nasal high-flow device in medical inpatients with an acute illness: a randomised controlled trial

Background

Guideline recommendations state oxygen should be administered to acutely unwell patients to achieve a target oxygen saturation (SpO₂) range. The current practice of manual oxygen titration frequently results in SpO₂ outside of a prescribed range. The aim of this study was to assess the efficacy of automatic oxygen titration using a closed-loop feedback system to achieve SpO₂ within a prescribed target range

Methods

An open-label randomised parallel group trial was undertaken comparing automatic oxygen titration using a novel nasal high-flow device to manual oxygen titration using nasal high flow. Medical inpatients requiring oxygen therapy in Wellington Regional Hospital, New Zealand with a prescribed target SpO₂ range of 88%–92% or 92%–96% were recruited and randomised equally between the interventions for a period of 24 hours. The primary outcome was the proportion of time spent with SpO₂ within the prescribed range.

Results

20 patients were included in the analysis. Automatic oxygen titration resulted in a median (IQR) 96.2% (95.2–97.8) of time within the target range compared with 71% (59.4–88.3) with manual titration; difference (95% CI) 24.2% (7.9% to 35%), p<0.001. There was a reduction in the time spent with SpO₂ ≥2% above and ≥2% below range in the automatic titration group, although the point estimate for the differences were small; −1% (−8.2% to −0.04%), p=0.017 and −2.4% (−11.5% to 0.3%), p=0.05 respectively.

Conclusions

Nasal high-flow with automatic oxygen titration resulted in a greater proportion of time spent with SpO₂ in target range compared with manual titration.

Trial registration

The trial was registered with the Australian and New Zealand Clinical Trials Registry (ACTRN12619000901101).

Perceptions of Hyperoxemia and Conservative Oxygen Therapy in the Management of Acute Respiratory Failure

Rationale: Mechanically ventilated patients in the intensive care unit (ICU) are often managed to maximize oxygenation, yet hyperoxemia may be deleterious to some. Little is known about how ICU providers weigh tradeoffs between hypoxemia and hyperoxemia when managing acute respiratory failure. Objectives: To define ICU providers' mental models for managing oxygenation for patients with acute respiratory failure and identify barriers and facilitators to conservative oxygen therapy. Methods: In two large U.S. tertiary care hospitals, we performed semistructured interviews with a purposive sample of ICU nurses, respiratory therapists, and physicians. We assessed perceptions of oxygenation management, hyperoxemia, and conservative oxygen therapies through interviews, which we audio recorded and transcribed verbatim. We analyzed transcripts for representative themes using an iterative thematic-analysis approach. Results: We interviewed 10 nurses, 10 respiratory therapists, 4 fellows, and 5 attending physicians before reaching thematic saturation. Major themes included perceptions of hyperoxemia, attitudes toward conservative oxygen therapy, and aspects of titrated-oxygen-therapy implementation. Many providers did not recognize the term "hyperoxemia," whereas others described a poor understanding; several stated they never encounter hyperoxemia clinically. Concerns about hyperoxemia varied: some providers believed that typical ventilation strategies emphasizing progressive lowering of the fraction of inspired oxygen mitigated worries about excess oxygen administration, whereas others maintained that hyperoxemia is harmful only to patients with chronic lung disease. Almost all interviewees expressed familiarity with lower oxygen saturations in chronic obstructive pulmonary disease. Cited barriers to conservative oxygen therapy included concerns about hypoxemia, particularly among nurses and respiratory therapists; perceptions that hyperoxemia is not harmful; and a lack of clear evidence supporting conservative oxygen therapy. Interviewees suggested that interprofessional education and convincing clinical trial evidence could facilitate uptake of conservative oxygenation. Conclusions: This study describes attitudes toward hyperoxemia and conservative oxygen therapy. These preferences and uncertain benefits and risks of conservative oxygen therapy should be considered during future implementation efforts. Successful oxygen therapy implementation most likely will require 1) improving awareness of hyperoxemia's effects, 2) normalizing lower saturations in patients without chronic lung disease, 3) addressing ingrained beliefs regarding oxygen management and oxygen's safety, and 4) using interprofessional education to obtain buy-in across providers and inform the ICU team.

Variable oxygen administration in surgical and medical wards evaluated by 30-day mortality-An observational study

BACKGROUND

Several studies in surgery and initial management of critical illness have indicated harmful effects of short-term exposure to hyperoxia. Exposure to and consequences of excessive oxygen administration in hospital wards are sparsely investigated. The aim of this study was to investigate the association between excessive oxygen administration in patients admitted to surgical or medical wards and 30-day mortality.

METHODS

We included patients in the Capital Region of Denmark who were admitted to hospital in 2014 for either myocardial infarction, acute exacerbation of chronic obstructive pulmonary disease (COPD), hip fracture or open abdominal surgery. We defined groups of inadequate, adequate or excessive oxygen administration based on peripheral oxygen saturation and oxygen administration values in the first 48 hours after admission. The primary outcome was mortality within 30 days, and data were analysed with multivariable logistic regression for age, gender and comorbidities.

RESULTS

We retrieved data from 11 196 patients, of which 81% had adequate, 18% had excessive and 1.8% inadequate oxygen administration. Mortality at 30 days was 4.2%, 7.6% and 27%, respectively, OR 1.46 (95%CI 1.16-1.84), P = .001 for patients with excessive compared to adequate oxygen administration. The association was significant in subgroups of patients admitted for acute exacerbation of COPD (OR 1.67, 95%CI 1.19-2.34) and myocardial infarction (OR 3.50, 95%CI 1.55-7.89).

CONCLUSION

Patients who received excessive oxygen administration in surgical and medical wards during the first 48 hours of admission had a higher mortality risk within 30 days compared to patients with adequate oxygen administration. However, inadequate oxygen therapy still renders highest mortality and should be avoided.

Liposomal drug delivery to manage nontuberculous mycobacterial pulmonary disease and other chronic lung infections

Nontuberculous mycobacterial (NTM) pulmonary disease is a chronic respiratory infection associated with declining lung function, radiological deterioration and significantly increased morbidity and mortality. Patients often have underlying lung conditions, particularly bronchiectasis and COPD. NTM pulmonary disease is difficult to treat because mycobacteria can evade host defences and antimicrobial therapy through extracellular persistence in biofilms and sequestration into macrophages. Management of NTM pulmonary disease remains challenging and outcomes are often poor, partly due to limited penetration of antibiotics into intracellular spaces and biofilms. Efficient drug delivery to the site of infection is therefore a key objective of treatment, but there is high variability in lung penetration by antibiotics. Inhalation is the most direct route of delivery and has demonstrated increased efficacy of antibiotics like amikacin compared with systemic administration. Liposomes are small, artificial, enclosed spherical vesicles, in which drug molecules can be encapsulated to provide controlled release, with potentially improved pharmacokinetics and reduced toxicity. They are especially useful for drugs where penetration of cell membranes is essential. Inhaled delivery of liposomal drug solutions can therefore facilitate direct access to macrophages in the lung where the infecting NTM may reside. A range of liposomal drugs are currently being evaluated in respiratory diseases.

Liposome-encapsulated antibiotics can optimise respiratory disease treatment. Amikacin liposomal inhalation suspension is effective in nontuberculous mycobacterial pulmonary disease that has failed to convert following oral guideline-based therapy.https://bit.ly/3f3ixIu

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

Introduction: Hypoxia is the main cause of morbidity and mortality in COVID-19. During the COVID-19 pandemic, some countries have reduced access to supplemental oxygen, whereas other nations have maintained and even improved access to supplemental oxygen. We examined whether variation in the nationally determined oxygen guidelines had any association with national mortality rates in COVID-19.

Methods: Three independent investigators searched for, identified, and extracted the nationally recommended target oxygen levels for the commencement of oxygen in COVID-19 pneumonia from the 29 worst affected countries. Mortality estimates were calculated from three independent sources. We then applied both parametric (Pearson's R) and non-parametric (Kendall's Tau B) tests of bivariate association to determine the relationship between case fatality rate (CFR) and target SpO₂, and also between potential confounders and CFR.

Results: 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. A statistically significant correlation was found between SpO₂ and CFR both parametrically (R = −0.53, P < 0.01) and non-parametrically (−0.474, P < 0.01).

Conclusion: Our study highlights the disparity in oxygen provision for COVID-19 patients between the nations analysed. In those nations that pursued a conservative oxygen strategy, there was an association with higher national mortality rates. We discuss the potential reasons for such an association.

Is oxygen therapy beneficial for normoxemic patients with acute heart failure? A propensity score matched study

BACKGROUND

The clinical efficiency of routine oxygen therapy is uncertain in patients with acute heart failure (AHF) who do not have hypoxemia. The aim of this study was to investigate the association between oxygen therapy and clinical outcomes in normoxemic patients hospitalized with AHF using real-world data.

METHODS

Normoxemic patients diagnosed with AHF on ICU admission from the electronic ICU (eICU) Collaborative Research Database were included in the current study, in which the study population was divided into the oxygen therapy group and the ambient-air group. Propensity score matching (PSM) was applied to create a balanced covariate distribution between patients receiving supplemental oxygen and those exposed to ambient air. Linear regression and logistic regression models were performed to assess the associations between oxygen therapy and length of stay (LOS), and all-cause in-hospital as well as ICU mortality rates, respectively. A series of sensitivity and subgroup analyses were conducted to further validate the robustness of our findings.

RESULTS

A total of 2922 normoxemic patients with AHF were finally included in the analysis. Overall, 42.1% (1230/2922) patients were exposed to oxygen therapy, and 57.9% (1692/2922) patients did not receive oxygen therapy (defined as the ambient-air group). After PSM analysis, 1122 pairs of patients were matched: each patient receiving oxygen therapy was matched with a patient without receiving supplemental oxygen. The multivariable logistic model showed that there was no significant interaction between the ambient air and oxygen group for all-cause in-hospital mortality [odds ratio (OR) 1.30; 95% confidence interval (CI) 0.92-1.82; P = 0.138] or ICU mortality (OR 1.39; 95% CI 0.83-2.32; P = 0.206) in the post-PSM cohorts. In addition, linear regression analysis revealed that oxygen therapy was associated with prolonged ICU LOS (OR 1.11; 95% CI 1.06-1.15; P <  0.001) and hospital LOS (OR 1.06; 95% CI 1.01-1.10; P = 0.009) after PSM. Furthermore, the absence of an effect of supplemental oxygen on mortality was consistent in all subgroups.

CONCLUSION

Routine use of supplemental oxygen in AHF patients without hypoxemia was not found to reduce all-cause in-hospital mortality or ICU mortality.

Understanding the principles of non-invasive positive pressure ventilation

Non-invasive positive pressure ventilation (NPPV) provides respiratory support to patients without the need for invasive intubation. Although it has been used for several years in critical care, NPPV has come to prominence as a management option for certain patients with respiratory complications of coronavirus disease 2019 (COVID-19). This has led to increased care provision by nurses with little or no experience and expertise in critical care and NPPV. This article provides an overview of the principles of NPPV and its use in type 1 and type 2 respiratory failure. It explains the pathophysiology of several conditions that often lead to respiratory failure and how NPPV can mitigate respiratory failure and improve gas exchange. An individualised assessment of the patient's suitability for NPPV and an evaluation of the effectiveness of the therapy are crucial to ensure its safe and effective use. Nurses also have an important role in providing explanations and support to patients.

Persisting and reoccurring cyanosis after Fontan operation is associated with increased late mortality

OBJECTIVES

The Fontan operation aims at reducing cyanosis and cardiac volume overload in patients with complex univentricular heart malformations. However, persisting or reoccurring cyanosis is frequently observed. We sought to systematically determine the prevalence and clinical consequences of persisting and secondary cyanosis after Fontan operation.

METHODS

A total of 331 Fontan patients, operated between 1984 and 2016 with a median postoperative follow-up of 7.9 (interquartile range 2.6-15.8) years, were studied retrospectively. Cyanosis was defined as transcutaneous oxygen saturation ≤93% at rest measured by pulse oximetry. Prevalence of cyanosis was analysed at 3 different time points (t1 = post-Fontan operation, t2 = post-Fontan cardiac catheterization, t3 = last follow-up) and the association of cyanosis with mortality was examined.

RESULTS

Prevalence of cyanosis was 50% at t1 and 39% at t3. Fenestration was patent in 71% and 33% of all cyanotic patients at t1 and t3, respectively. In patients with clinical indication for catheterization (t2; n = 178/331), prevalence of cyanosis was 72%. At t2, patent fenestration (33%), veno-venous collaterals (24%) or both (32%) were present. Thirty-six (11%) patients died during follow-up. In a time-varying multivariable Cox regression analysis, cyanosis was the strongest predictor for late mortality (P < 0.001, hazard ratio 12.2, 95% confidence interval 3.7-40.5).

CONCLUSIONS

Prevalence of cyanosis was considerable during long-term follow-up after Fontan operation and-as a surrogate parameter for unfavourable Fontan haemodynamics-is associated with increased late mortality. Accordingly, particular attention should be directed towards the persistence or reoccurrence of cyanosis during follow-up since it may indicate haemodynamic attrition and development of Fontan failure.

Acute oxygen use in hospitalised patients with chronic obstructive pulmonary disease is guideline discordant

Ample evidence supports an association between acute oxygen over-administration and harm. Australian and international guidelines consistently recommend lower oxygen saturation aims in populations with chronic obstructive pulmonary disease (COPD). We assessed adherence to acute oxygen use guidelines and outcomes in hospitalised patients with COPD at a large Australian metropolitan hospital network.

[Cardiac arrest under special circumstances]

These guidelines of the European Resuscitation Council (ERC) Cardiac Arrest under Special Circumstances are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required for basic and advanced life support for the prevention and treatment of cardiac arrest under special circumstances; in particular, specific causes (hypoxia, trauma, anaphylaxis, sepsis, hypo-/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), specific settings (operating room, cardiac surgery, cardiac catheterization laboratory, dialysis unit, dental clinics, transportation [in-flight, cruise ships], sport, drowning, mass casualty incidents), and specific patient groups (asthma and chronic obstructive pulmonary disease, neurological disease, morbid obesity, pregnancy).

Atezolizumab-induced anaphylactic shock in a patient with hepatocellular carcinoma undergoing immunotherapy: A case report

BACKGROUND

Atezolizumab is a programmed death ligand 1 (PD-L1) inhibitor, and its combination with bevacizumab has been proven an effective immunotherapy for unresectable hepatocellular carcinoma (HCC). Treatment with immune checkpoint inhibitors (ICIs) can lead to hypersensitivity reactions; however, anaphylactic shock is rare. We present a case of life-threatening anaphylactic shock during atezolizumab infusion and performed a relevant literature review.

CASE SUMMARY

A 75-year-old man was diagnosed with HCC recurrence after hepatectomy. He was administered immunotherapy with atezolizumab plus bevacizumab after an allergy to a programmed death-1 (PD-1) inhibitor. The patient showed a sudden onset of dizziness, numbness, and lack of consciousness with severe hypotension during atezolizumab infusion. The treatment was stopped immediately. The patient’s symptoms resolved after 5 mg dexamethasone was administered. Because of repeated hypersensitivity reactions to ICIs, treatment was changed to oral targeted regorafenib therapy.

CONCLUSION

Further research is necessary for elucidating the hypersensitivity mechanisms and establishing standardized skin test and desensitization protocols associated with PD-1 and PD-L1 to ensure effective treatment with ICIs.

Conservative versus liberal oxygen therapy for acutely ill medical patients: A systematic review and meta-analysis

BACKGROUND

The role of conservative versus liberal oxygen therapy for acutely ill patients remains controversial.

OBJECTIVE

To systematically review the available evidence regarding the efficacy and safety of conservative oxygen therapy compared with liberal oxygen therapy for acutely ill patients.

METHODS

A systematic search of Medline, Embase, and the Cochrane Central Register was conducted from their inception until April 5, 2020. Randomized clinical trials evaluating a high-target (liberal) or a low-target (conservative) oxygenation strategy in adults with an acutely ill condition were eligible for inclusion. A meta-analysis using random-effects models was conducted to calculate the risk ratio with corresponding 95% confidence intervals. Heterogeneity and publication bias were evaluated.

RESULTS

The analyses included 33 randomized clinical trials with a total of 17,780 participants. Compared with conservative oxygen therapy, liberal oxygen therapy was not associated with increased mortality at 30 days (risk ratio 1.09, 95% confidence intervals 0.98-1.22; I2=0%), at 90 days (risk ratio 1.00, 95% confidence intervals 0.88-1.13, I2=37%), or at the longest follow-up (risk ratio 1.04, 95% confidence intervals 0.96-1.12, I2=0%). Good functional outcome was similar between groups. Findings were robust to trial sequential, subgroup, and sensitivity analyses.

CONCLUSIONS

Compared with liberal oxygen therapy, conservative oxygen therapy was not associated with decreased mortality. Tweetable abstract: Compared with liberal oxygen therapy, conservative oxygen therapy was not associated with decreased mortality.

Nontuberculous mycobacterial pulmonary disease: an integrated approach beyond antibiotics

Nontuberculous mycobacterial (NTM) pulmonary disease (PD) is an emerging condition with heterogeneous manifestations from both the microbiological and the clinical point of view. Diagnostic and therapeutic guidelines are available but there are still unmet patients' and physicians' needs, including therapy-related adverse events, symptom control, management of comorbidities, risk of re-exposure to the pathogen and unfavourable outcomes.

In the present review, we provide currently available evidence for an integrated approach to NTM-PD beyond antibiotic therapy. This includes 1) avoiding exposure to environments where mycobacteria are present and careful evaluation of lifestyle and habits; 2) implementing a personalised pulmonary rehabilitation plan and airway clearance techniques to improve symptoms, exercise capacity, health-related quality of life (QoL) and functional capacity in daily living activities; 3) a nutritional evaluation and intervention to improve health-related QoL and to control gastrointestinal side-effects during antimicrobial therapy, particularly in those with low body mass index and history of weight loss; and 4) managing comorbidities that affect disease outcomes, including structural lung diseases, immune status evaluation and psychological support when appropriate.

An integrated approach, including risk factor prevention, management of comorbidities, nutritional evaluation and intervention and pulmonary rehabilitation, should be considered in the optimal management of nontuberculous mycobacterial pulmonary diseasehttps://bit.ly/2YEqvQg

Improvements and Shortcomings in Emergency Oxygen Prescribing: A Quality Improvement Initiative at an Acute Tertiary Care Hospital

Oxygen is one of the most commonly used yet poorly prescribed drugs. The 2015 British Thoracic Society (BTS) emergency oxygen audit highlighted the national shortcomings in oxygen prescribing and administration. A 2017 local audit at the Royal Sussex County Hospital, Brighton, UK, continued to demonstrate poor compliance with the BTS Oxygen Prescribing Guidelines in all areas audited. This study carried out yearly reaudits in November 2018 and 2019 to objectively measure the impact of implementing trust-wide and local interventions (July 2018 and August 2019).Intervention 1 included introduction of the National Early Warning Score (NEWS2) scale and redesigning drug charts with tick-boxes for target oxygen saturations. Intervention 2 included mandatory junior doctor teaching on safe oxygen prescribing, ‘oxygen safety’ posters on audited wards, and reminders at handover for staff to measure and document oxygen saturations.Following Intervention 1, all patients with valid oxygen prescriptions had a specified target saturations range. Intervention 2 ensured all patients had actual saturations within their prescribed target range, and 99% had oxygen saturations documented with sufficient frequency for their NEWS2 score. These were huge improvements from previous audits, during which a significant proportion of patients were at risk of hypercapnia, and those over- or underoxygenated were left unrecognised for hours. Despite improvements, 14% of patients continued to use oxygen without valid prescriptions in 2019, and drug charts were inconsistently signed for during drug rounds.Although the implemented changes enabled drastic improvements for patient safety and quality in oxygen use, future work should ensure oxygen is always treated as a drug with suitable prescription and documentation.

Determining a target SpO2 to maintain PaO2 within a physiological range

OBJECTIVE

In the context of an ongoing debate on the potential risks of hypoxemia and hyperoxemia, it seems prudent to maintain the partial arterial oxygen pressure (PaO2) in a physiological range during administration of supplemental oxygen. The PaO2 and peripheral oxygen saturation (SpO2) are closely related and both are used to monitor oxygenation status. However, SpO2 values cannot be used as an exact substitute for PaO2. The aim of this study in acutely ill and stable patients was to determine at which SpO2 level PaO2 is more or less certain to be in the physiological range.

METHODS

This is an observational study prospectively collecting data pairs of PaO2 and SpO2 values in patients admitted to the emergency room or intensive care unit (Prospective Inpatient Acutely ill cohort; PIA cohort). A second cohort of retrospective data of patients who underwent pulmonary function testing was also included (Retrospective Outpatient Pulmonary cohort; ROP cohort). Arterial hypoxemia was defined as PaO2 < 60 mmHg and hyperoxemia as PaO2 > 125 mmHg. The SpO2 cut-off values with the lowest risk of hypoxemia and hyperoxemia were determined as the 95th percentile of the observed SpO2 values corresponding with the observed hypoxemic and hyperoxemic PaO2 values.

RESULTS

220 data pairs were collected in the PIA cohort. 95% of hypoxemic PaO2 measurements occurred in patients with an SpO2 below 94%, and 95% of hyperoxemic PaO2 measurements occurred in patients with an SpO2 above 96%. Additionally in the 1379 data pairs of the ROP cohort, 95% of hypoxemic PaO2 measurements occurred in patients with an SpO2 below 93%.

CONCLUSION

The SpO2 level marking an increased risk of arterial hypoxemia is not substantially different in acutely ill versus stable patients. In acutely ill patients receiving supplemental oxygen an SpO2 target of 95% maximizes the likelihood of maintaining PaO2 in the physiological range.

Lower or Higher Oxygenation Targets for Acute Hypoxemic Respiratory Failure

BACKGROUND

Patients with acute hypoxemic respiratory failure in the intensive care unit (ICU) are treated with supplemental oxygen, but the benefits and harms of different oxygenation targets are unclear. We hypothesized that using a lower target for partial pressure of arterial oxygen (Pao₂) would result in lower mortality than using a higher target.

METHODS

In this multicenter trial, we randomly assigned 2928 adult patients who had recently been admitted to the ICU (≤12 hours before randomization) and who were receiving at least 10 liters of oxygen per minute in an open system or had a fraction of inspired oxygen of at least 0.50 in a closed system to receive oxygen therapy targeting a Pao₂ of either 60 mm Hg (lower-oxygenation group) or 90 mm Hg (higher-oxygenation group) for a maximum of 90 days. The primary outcome was death within 90 days.

RESULTS

At 90 days, 618 of 1441 patients (42.9%) in the lower-oxygenation group and 613 of 1447 patients (42.4%) in the higher-oxygenation group had died (adjusted risk ratio, 1.02; 95% confidence interval, 0.94 to 1.11; P = 0.64). At 90 days, there was no significant between-group difference in the percentage of days that patients were alive without life support or in the percentage of days they were alive after hospital discharge. The percentages of patients who had new episodes of shock, myocardial ischemia, ischemic stroke, or intestinal ischemia were similar in the two groups (P = 0.24).

CONCLUSIONS

Among adult patients with acute hypoxemic respiratory failure in the ICU, a lower oxygenation target did not result in lower mortality than a higher target at 90 days. (Funded by the Innovation Fund Denmark and others; HOT-ICU ClinicalTrials.gov number, NCT03174002.).

European Resuscitation Council Guidelines 2021: Cardiac arrest in special circumstances

These European Resuscitation Council (ERC) Cardiac Arrest in Special Circumstances guidelines are based on the 2020 International Consensus on Cardiopulmonary Resuscitation Science with Treatment Recommendations. This section provides guidelines on the modifications required to basic and advanced life support for the prevention and treatment of cardiac arrest in special circumstances; specifically special causes (hypoxia, trauma, anaphylaxis, sepsis, hypo/hyperkalaemia and other electrolyte disorders, hypothermia, avalanche, hyperthermia and malignant hyperthermia, pulmonary embolism, coronary thrombosis, cardiac tamponade, tension pneumothorax, toxic agents), special settings (operating room, cardiac surgery, catheter laboratory, dialysis unit, dental clinics, transportation (in-flight, cruise ships), sport, drowning, mass casualty incidents), and special patient groups (asthma and COPD, neurological disease, obesity, pregnancy).

Direct and indirect evidence of efficacy and safety of rapid exercise tests for exertional desaturation in Covid-19: a rapid systematic review

BACKGROUND

Even when resting pulse oximetry is normal in the patient with acute Covid-19, hypoxia can manifest on exertion. We summarise the literature on the performance of different rapid tests for exertional desaturation and draw on this evidence base to provide guidance in the context of acute Covid-19.

MAIN RESEARCH QUESTIONS

1. What exercise tests have been used to assess exertional hypoxia at home or in an ambulatory setting in the context of Covid-19 and to what extent have they been validated? 2. What exercise tests have been used to assess exertional hypoxia in other lung conditions, to what extent have they been validated and what is the applicability of these studies to acute Covid-19?

METHOD

AMED, CINAHL, EMBASE MEDLINE, Cochrane and PubMed using LitCovid, Scholar and Google databases were searched to September 2020. Studies where participants had Covid-19 or another lung disease and underwent any form of exercise test which was compared to a reference standard were eligible. Risk of bias was assessed using QUADAS 2. A protocol for the review was published on the Medrxiv database.

RESULTS

Of 47 relevant papers, 15 were empirical studies, of which 11 described an attempt to validate one or more exercise desaturation tests in lung diseases other than Covid-19. In all but one of these, methodological quality was poor or impossible to fully assess. None had been designed as a formal validation study (most used simple tests of correlation). Only one validation study (comparing a 1-min sit-to-stand test [1MSTST] with reference to the 6-min walk test [6MWT] in 107 patients with interstitial lung disease) contained sufficient raw data for us to calculate the sensitivity (88%), specificity (81%) and positive and negative predictive value (79% and 89% respectively) of the 1MSTST. The other 4 empirical studies included two predictive studies on patients with Covid-19, and two on HIV-positive patients with suspected pneumocystis pneumonia. We found no studies on the 40-step walk test (a less demanding test that is widely used in clinical practice to assess Covid-19 patients). Heterogeneity of study design precluded meta-analysis.

DISCUSSION

Exertional desaturation tests have not yet been validated in patients with (or suspected of having) Covid-19. A stronger evidence base exists for the diagnostic accuracy of the 1MSTST in chronic long-term pulmonary disease; the relative intensity of this test may raise safety concerns in remote consultations or unstable patients. The less strenuous 40-step walk test should be urgently evaluated.

A strange case of severe but fleeting hypoxemia in patient with COVID-19 infection: maybe virus-induced pulmonary Raynaud's phenomenon?

This case-report describes severe acute respiratory failure in a patient with a COVID-19 positive nasopharyngeal swab that spontaneously resolved within a few hours. It is speculated that the virus may have caused a fleeting pulmonary vasospasm.

Critical Care Management of the Patient With Anaphylaxis: A Concise Definitive Review

OBJECTIVES

Anaphylaxis is a rapidly progressive life-threatening syndrome manifesting as pruritus, urticaria, angioedema, bronchospasm and shock. The goal of this synthetic review is to provide a practical, updated approach to the evaluation and management of this disorder and associated complications.

DATA SOURCES

A MEDLINE search was conducted with the MeSH of anaphylaxis, anaphylactic reaction, anaphylactic shock, refractory anaphylaxis and subheadings of diagnosis, classification, epidemiology, complications and pharmacology. The level of evidence supporting an intervention was evaluated based on the availability of randomized studies, expert opinion, case studies, reviews, practice parameters and other databases (including Cochrane).

STUDY SELECTION

Selected publications describing anaphylaxis, clinical trials, diagnosis, mechanisms, risk factors and management were retrieved (reviews, guidelines, clinical trials, case series) and their bibliographies were also reviewed to identify relevant publications.

DATA EXTRACTION

Data from the relevant publications were reviewed, summarized and the information synthesized.

DATA SYNTHESIS

This is a synthetic review and the data obtained from a literature review was utilized to describe current trends in the diagnosis and management of the patient with anaphylaxis with a special emphasis on newer evolving concepts of anaphylaxis endotypes and phenotypes, management of refractory anaphylaxis in the ICU setting and review of therapeutic options for the elderly patient, or the complicated patient with severe cardiorespiratory complications. Most of the recommendations come from practice parameters, case studies or expert opinions, with a dearth of randomized trials to support specific interventions.

CONCLUSION

Anaphylaxis is a rapidly progressive life-threatening disorder. The critical care physician needs to be familiar with the diagnosis, differential diagnosis, evaluation, and management of anaphylaxis. Skilled intervention in ICUs may be required for the patient with complicated, severe, or refractory anaphylaxis.