Pre-hospital oxygen therapy in acute exacerbations of chronic obstructive pulmonary disease

Standard vs. targeted oxygen therapy prehospitally for chronic obstructive pulmonary disease (STOP-COPD): study protocol for a randomised controlled trial

BACKGROUND

A high concentration of inspired supplemental oxygen may possibly cause hypercapnia and acidosis and increase mortality in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). Even so, patients with AECOPD are being treated with high oxygen flow rates when receiving inhalation drugs in the prehospital setting. A cluster-randomised controlled trial found that reduced oxygen delivery by titrated treatment reduced mortality-a result supported by observational studies-but the results have never been reproduced. In the STOP-COPD trial, we investigate the effect of titrated oxygen delivery compared with usual care consisting of high flow oxygen delivery in patients with AECOPD in the prehospital setting.

METHODS

In this randomised controlled trial, patients will be blinded to allocation. Patients with suspected AECOPD (n = 1888) attended by the emergency medical service (EMS) and aged > 40 years will be allocated randomly to either standard treatment or titrated oxygen, targeting a blood oxygen saturation of 88-92% during inhalation therapy. The trial will be conducted in the Central Denmark Region and include all ambulance units. The power to detect a 3% 30-day mortality risk difference is 80%. The trial is approved as an emergency trial. Hence, EMS providers will include patients without prior consent.

DISCUSSION

The results will provide evidence on whether titrated oxygen delivery outperforms standard high flow oxygen when used to nebulise inhaled bronchodilators in AECOPD treatment. The trial is designed to ensure unselected inclusion of patients with AECOPD needing nebulised bronchodilators-a group of patients that receives high oxygen fractions when treated in the prehospital setting where the only compressed gas is generally pure oxygen. Conducting this trial, we aim to improve treatment for people with AECOPD while reducing their 30-day mortality.

TRIAL REGISTRATION

European Union Clinical Trials (EUCT) number: 2022-502003-30-00 (authorised 06/12/2022), ClinicalTrials.gov number: NCT05703919 (released 02/02/2023), Universal trial number: U1111-1278-2162.

[Non-invasive Mechanical Ventilation in Acute Respiratory Failure. Clinical Practice Guidelines - on behalf of the German Society of Pneumology and Ventilatory Medicine]

The guideline update outlines the advantages as well as the limitations of NIV in the treatment of acute respiratory failure in daily clinical practice and in different indications.Non-invasive ventilation (NIV) has a high value in therapy of hypercapnic acute respiratory failure, as it significantly reduces the length of ICU stay and hospitalization as well as mortality.Patients with cardiopulmonary edema and acute respiratory failure should be treated with continuous positive airway pressure (CPAP) and oxygen in addition to necessary cardiological interventions. This should be done already prehospital and in the emergency department.In case of other forms of acute hypoxaemic respiratory failure with only mild or moderately disturbed gas exchange (PaO2/FiO2 > 150 mmHg) there is no significant advantage or disadvantage compared to high flow nasal oxygen (HFNO). In severe forms of ARDS NIV is associated with high rates of treatment failure and mortality, especially in cases with NIV-failure and delayed intubation.NIV should be used for preoxygenation before intubation. In patients at risk, NIV is recommended to reduce extubation failure. In the weaning process from invasive ventilation NIV essentially reduces the risk of reintubation in hypercapnic patients. NIV is regarded useful within palliative care for reduction of dyspnea and improving quality of life, but here in concurrence to HFNO, which is regarded as more comfortable. Meanwhile NIV is also recommended in prehospital setting, especially in hypercapnic respiratory failure and pulmonary edema.With appropriate monitoring in an intensive care unit NIV can also be successfully applied in pediatric patients with acute respiratory insufficiency.

Doctors' and Nurses' Knowledge and Perceived Barriers Regarding Acute Oxygen Therapy in a Tertiary Care Hospital in Nigeria

PURPOSE

Oxygen may cause serious consequences when administered wrongly. This study aimed to assess doctors' and nurses' knowledge of acute oxygen therapy and perceived delivery barriers.

PARTICIPANTS AND METHODS

We conducted a cross sectional study among 202 healthcare providers (134 doctors and 68 nurses) in a Nigerian hospital. The validated Acute Oxygen Therapy Questionnaire (AOTQ), which consisted of 21 knowledge assessment questions, was self administered by participants. Provider's knowledge was classified as good if the score was≥80% and poor if < 60%.

RESULTS

Overall, 26.7% (37.3% doctors and 5.9% nurses) had good knowledge of acute oxygen therapy (AOT), 35.9% were aware, and 19.3% used the AOT guidelines. The commonest source of knowledge on oxygen therapy was medical /nursing school (75.2%). The participants' mean knowledge score was 14.75 ± 2.83(possible score of 0-21). Doctors in postgraduate (PG) training obtained the highest score (15.96±2.48) among the participants (F=12.45, df=4, p<0.001). Most doctors (62%) and 23.5% of nurses considered oxygen as a drug. More doctors (52.2%) than nurses (14.7%) believed that a doctor's order was mandatory before oxygen administration, contrary to guidelines recommendations. Most nurses did not know that breathlessness does not always signify hypoxemia and that asymptomatic anemia was not an indication for oxygen. Concerning oxygen prescription, 39.7% of nurses and 64.2% of doctors knew that it should be prescribed to achieve a target saturation range rather than a fixed dose. In acute oxygen delivery in COPD, doctors and nurses exhibited poor knowledge of the appropriate device and flow rate. The reported barriers to oxygen delivery were: a shortage of oxygen supply, inadequate delivery devices, power outages and out of pocket costs.

CONCLUSION

A significant proportion of doctors and nurses had poor knowledge of acute oxygen therapy, poor awareness and infrequently used AOT guidelines, and reported pertinent delivery barriers that warrant educational and administrative interventions.

Oxygen-induced hypercapnia: physiological mechanisms and clinical implications

Oxygen is probably the most commonly prescribed drug in the emergency setting and is a life-saving modality as well. However, like any other drug, oxygen therapy may also lead to various adverse effects. Patients with chronic obstructive pulmonary disease (COPD) may develop hypercapnia during supplemental oxygen therapy, particularly if uncontrolled. The risk of hypercapnia is not restricted to COPD only; it has also been reported in patients with morbid obesity, asthma, cystic fibrosis, chest wall skeletal deformities, bronchiectasis, chest wall deformities, or neuromuscular disorders. However, the risk of hypercapnia should not be a deterrent to oxygen therapy in hypoxemic patients with chronic lung diseases, as hypoxemia may lead to life-threatening cardiovascular complications. Various mechanisms leading to the development of oxygen-induced hypercapnia are the abolition of ‘hypoxic drive’, loss of hypoxic vasoconstriction and absorption atelectasis leading to an increase in dead-space ventilation and Haldane effect. The international guideline recommends a target oxygen saturation of 88% to 92% in patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD) and other chronic lung diseases at risk of hypercapnia.  Oxygen should be administered only when oxygen saturation is below 88%. We searched PubMed, EMBASE, and the CINAHL from inception to June 2022. We used the following search terms: “Hypercapnia”, “Oxygen therapy in COPD”, “Oxygen-associated hypercapnia”, “oxygen therapy”, and “Hypoxic drive”. All types of study are selected. This review will focus on the physiological mechanisms of oxygen-induced hypercapnia and its clinical implications.

Adaptive Responses to Hypoxia and/or Hyperoxia in Humans

Significance: Oxygen is indispensable for aerobic life, but its utilization exposes cells and tissues to oxidative stress; thus, tight regulation of cellular, tissue, and systemic oxygen concentrations is crucial. Here, we review the current understanding of how the human organism (mal-)adapts to low (hypoxia) and high (hyperoxia) oxygen levels and how these adaptations may be harnessed as therapeutic or performance enhancing strategies at the systemic level. Recent Advances: Hyperbaric oxygen therapy is already a cornerstone of modern medicine, and the application of mild hypoxia, that is, hypoxia conditioning (HC), to strengthen the resilience of organs or the whole body to severe hypoxic insults is an important preparation for high-altitude sojourns or to protect the cardiovascular system from hypoxic/ischemic damage. Many other applications of adaptations to hypo- and/or hyperoxia are only just emerging. HC-sometimes in combination with hyperoxic interventions-is gaining traction for the treatment of chronic diseases, including numerous neurological disorders, and for performance enhancement. Critical Issues: The dose- and intensity-dependent effects of varying oxygen concentrations render hypoxia- and/or hyperoxia-based interventions potentially highly beneficial, yet hazardous, although the risks versus benefits are as yet ill-defined. Future Directions: The field of low and high oxygen conditioning is expanding rapidly, and novel applications are increasingly recognized, for example, the modulation of aging processes, mood disorders, or metabolic diseases. To advance hypoxia/hyperoxia conditioning to clinical applications, more research on the effects of the intensity, duration, and frequency of altered oxygen concentrations, as well as on individual vulnerabilities to such interventions, is paramount. Antioxid. Redox Signal. 37, 887-912.

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.

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.

Analysis of compliance of the criteria recommended by the European resucitation council in first aid books published in Spanish

AIMS

Analyse the compliance of criteria recommended by the European Resuscitation Council (ERC) in the layperson First Aid (FA) and Cardiopulmonary resuscitation (CPR) books published in Spanish.

METHODS

A review of FA literature published in Spain, carried out through a systematic literature search procedure. We drew up a checklist with clarifications, based on different responses to twenty categories published in November 2015 by the ERC. The validity of the questions was analysed using the Fleiss' Kappa measure of inter-rater reliability, with a value >0.7 being deemed valid and questions displaying the lowest level of agreement being excluded.

RESULTS

Eight texts obtained from the limited search of materials published between 2016-2020 in the ISBN 13 database were analysed. Evaluation of eight texts ranging from 47 to 328 pages in length showed that only three included the upgraded 2015 CPR recommendations. Twenty categories/items were analysed, after exclusion of categories/items that displayed a low consistency. None of the handbooks was in total compliance with the new CPR recommendations, and only one included 70% of the recommendations. Seven categories were included in more than 50% of the texts, and nine categories were not included in any of them.

CONCLUSIONS

There is a gap between the 2015 CPR recommendations and those published in Spanish FA handbooks. The ERC Guidelines should serve to standardise FA and CPR training materials. Systematic analysis of compliance with scientific societies' recommendations for FA handbooks enables detection of guidelines and patterns that need to be updated and adapted.

Comparison of high-flow oxygenation with noninvasive ventilation in COPD exacerbation: A crossover clinical trial

OBJECTIVES

To compare the therapeutic effects of high-flow-oxygen-Therapy (HFT) and noninvasive-ventilation (NIV) for stabilizing chronic obstructive pulmonary disease during exacerbation.

METHODS

In this randomized clinical trial at Masih-Daneshvari hospital, between July 2019 and Oct 2019, 30 exacerbated-COPD-patient with PaCO₂ 64.58 ± 11.61 mm Hg, Respiratory Rate 24.43 ± 2.75, and PH 7.31 ± 0.02 were divided into two groups, N = 15. By a simple randomized allocation, patients receive either NIV or HFT for 1 hour, and following a washout period of 30 minutes, they switched to the other treatment option. Arterial Blood Gas Parameters, as well as Respiratory Rate (RR), Dyspnea Score, Heart Rate (HR), and Oxygen Saturation (SO₂ ), were compared before and after the intervention and between groups.

RESULTS

Baseline patient characteristics were similar in the two groups. Pre and post-analysis revealed that in both groups, all improved significantly. After the first period, there was no difference in all parameters between groups except for SO₂ which was significantly higher in HFT (%92.1 ± 1) than that of NIV (%89 ± 1), P = .001. Likewise, following the washout period, patients in HFT and NIV had a dyspnea score of 1.93 ± 0.7 and 2.73 ± 0.9, respectively, P = .01. No carryover-effect and was observed but the period effect was significant for some outcomes. A significant improvement in SO₂ and HR was observed by HFT according to treatment effect by combining two periods' results. During the study, no side effects were reported.

CONCLUSION

In this short-term study HFT appears feasible for patients with COPD exacerbation to reduce dyspnea score and improve respiratory distress.

Adult Patients with Respiratory Distress: Current Evidence-based Recommendations for Prehospital Care

INTRODUCTION

We developed evidence-based recommendations for prehospital evaluation and treatment of adult patients with respiratory distress. These recommendations are compared with current protocols used by the 33 local emergency medical services agencies (LEMSA) in California.

METHODS

We performed a review of the evidence in the prehospital treatment of adult patients with respiratory distress. The quality of evidence was rated and used to form guidelines. We then compared the respiratory distress protocols of each of the 33 LEMSAs for consistency with these recommendations.

RESULTS

PICO (population/problem, intervention, control group, outcome) questions investigated were treatment with oxygen, albuterol, ipratropium, steroids, nitroglycerin, furosemide, and non-invasive ventilation. Literature review revealed that oxygen titration to no more than 94-96% for most acutely ill medical patients and to 88-92% in patients with acute chronic obstructive pulmonary disease (COPD) exacerbation is associated with decreased mortality. In patients with bronchospastic disease, the data shows improved symptoms and peak flow rates after the administration of albuterol. There is limited data regarding prehospital use of ipratropium, and the benefit is less clear. The literature supports the use of systemic steroids in those with asthma and COPD to improve symptoms and decrease hospital admissions. There is weak evidence to support the use of nitrates in critically ill, hypertensive patients with acute pulmonary edema (APE) and moderate evidence that furosemide may be harmful if administered prehospital to patients with suspected APE. Non-invasive positive pressure ventilation (NIPPV) is shown in the literature to be safe and effective in the treatment of respiratory distress due to acute pulmonary edema, bronchospasm, and other conditions. It decreases both mortality and the need for intubation. Albuterol, nitroglycerin, and NIPPV were found in the protocols of every LEMSA. Ipratropium, furosemide, and oxygen titration were found in a proportion of the protocols, and steroids were not prescribed in any LEMSA protocol.

CONCLUSION

Prehospital treatment of adult patients with respiratory distress varies widely across California. We present evidence-based recommendations for the prehospital treatment of undifferentiated adult patients with respiratory distress that will assist with standardizing management and may be useful for EMS medical directors when creating and revising protocols.

Long-term effect of hyperoxemia during chronic obstructive pulmonary disease exacerbation managed by emergency medical service and emergency department: a prospective, exploratory study

OBJECTIVE

Long-term effects of hyperoxemia during acute exacerbation of chronic obstructive pulmonary disease (AECOPD) remained unknown. We aimed to explore these effects of hyperoxemia during AECOPD.

METHODS

This was an exploratory follow-up study of a cohort with AECOPD managed by Emergency Medical Service and two emergency departments (EDs). Patients were classified as hyperoxemic (PaO2 > 65 mmHg) or nonhyperoxemic (PaO2 ≤ 65 mmHg). Patients discharged from ED/inpatient care were followed up prospectively for 1 year. The primary outcome was 1-year all-cause mortality in hyperoxemic vs. nonhyperoxemic groups. Secondary outcomes were 3-month all-cause mortality and median number of repeat AECOPD hospitalizations within 1 year. We generated Kaplan-Meier curves and compared them using log-rank test. The primary outcome was also analyzed using Cox proportional-hazards model. We reported crude and adjusted hazard ratios, their 95% confidence intervals (CIs) and P values. We adjusted for two a priori predictors of delayed mortality; age ≥ 70 years and repeat AECOPD hospitalizations.

RESULTS

A total of 231 patients were analyzed. One-year mortality rates in hyperoxemic vs. nonhyperoxemic groups were 26/137 (19.0%) and 12/94 (12.8%), respectively (P = 0.693). Although Kaplan-Meier curves showed divergent courses favoring nonhyperoxemic group, log-rank test was not statistically significant (P = 0.203). The crude and adjusted hazard ratios (reference: nonhyperoxemic group) were 1.55 (95% CIs, 0.78-3.08; P = 0.207) and 1.57 (95% CIs, 0.79-3.13; P = 0.196), respectively. Secondary outcomes did not differ.

CONCLUSIONS

Our study reported no effect on 1-year all-cause mortality associated with hyperoxemia during AECOPD. Further studies are needed to prove/disprove our findings.

Oxygen therapy in the pre-hospital setting for acute exacerbations of chronic obstructive pulmonary disease

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a global leading cause of morbidity and mortality, characterised by acute deterioration in symptoms. During these exacerbations, people are prone to developing alveolar hypoventilation, which may be partly caused by the administration of high inspired oxygen concentrations.

OBJECTIVES

To determine the effect of different inspired oxygen concentrations ("high flow" compared to "controlled") in the pre-hospital setting (prior to casualty/emergency department) on outcomes for people with acute exacerbations of COPD (AECOPD).

SEARCH METHODS

The Cochrane Airways Group Specialised Register, reference lists of articles and online clinical trial databases were searched. Authors of identified randomised controlled trials (RCTs) were also contacted for details of other relevant published and unpublished studies. The most recent search was conducted on 16 September 2019.

SELECTION CRITERIA

We included RCTs comparing oxygen therapy at different concentrations or oxygen therapy versus placebo in the pre-hospital setting for treatment of AECOPD.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. The primary outcome was all-cause and respiratory-related mortality.

MAIN RESULTS

The search identified a total of 824 citations; one study was identified for inclusion and two studies are awaiting classification. The 214 participants involved in the included study were adults with AECOPD, receiving treatment by paramedics en route to hospital. The mean age of participants was 68 years. A reduction in pre/in-hospital mortality was observed in favour of the titrated oxygen group (two deaths in the titrated oxygen group compared to 11 deaths in the high-flow control arm; risk ratio (RR) 0.22, 95% confidence interval (CI) 0.05 to 0.97; 214 participants). This translates to an absolute effect of 94 per 1000 (high-flow oxygen) compared to 21 per 1000 (titrated oxygen), and a number needed to treat for an additional beneficial outcome (NNTB) of 14 (95% CI 12 to 355) with titrated oxygen therapy. Other than mortality, no other adverse events were reported in the included study. Wide confidence intervals were observed between groups for arterial blood gas (though this may be confounded by protocol infidelity in the included study for this outcome measure), treatment failure requiring invasive or non-invasive ventilation or hospital utilisation. No data were reported for quality of life, lung function or dyspnoea. Risk of bias within the included study was largely unclear, though there was high risk of bias in domains relating to performance and attrition bias. We judged the evidence to be of low certainty, according to GRADE criteria.

AUTHORS' CONCLUSIONS

The one included study found a reduction in pre/in-hospital mortality for the titrated oxygen arm compared to the high-flow control arm. However, the paucity of evidence somewhat limits the reliability of these findings and generalisability to other settings. There is a need for robust, well-designed RCTs to further investigate the effect of oxygen therapies in the pre-hospital setting for people with AECOPD.

Pre-hospital and emergency department pathways of care for exacerbations of chronic obstructive pulmonary disease (COPD)

Exacerbations are serious complications of chronic obstructive pulmonary disease (COPD) that often require acute care from pre-hospital and emergency department (ED) services. Despite being a frequent cause of emergency presentations, gaps remain in both literature and practice for emergency care pathways of COPD exacerbations. This review seeks to address these gaps and focuses on the literature of pre-hospital and ED systems of care and how these intersect with patients experiencing an exacerbation of COPD. The literature in this area is expanding rapidly; however, more research is required to further understand exacerbations and how they are addressed by emergency medical services worldwide. For the purpose of this review, the pre-hospital domain includes ambulance and other emergency transport services, and encompasses medical interventions delivered prior to arrival at an ED or hospital. The ED domain is defined as the area of a hospital or free-standing centre where patients arrive to receive emergent medical care prior to admission. In many studies there is a significant overlap between these two domains and frequent intersection and collaboration between services. In both of these domains, for the management of COPD exacerbations, several overarching themes have been identified in the literature. These include: the appropriate delivery of oxygen in the emergency setting; strategies to improve the provision of care in accordance with diagnostic and treatment guidelines; strategies to reduce the requirement for emergency presentations; and, technological advances including machine learning which are helping to improve emergency healthcare systems.

Development and validation of a questionnaire to assess the doctors and nurses knowledge of acute oxygen therapy

Background

Prescription and administration of oxygen in emergencies by healthcare providers are reported to be inappropriate in most settings. There is a huge gap in the knowledge of health care providers on various aspects of oxygen therapy, and this may be a barrier to optimal oxygen administration. Hence, it is essential to ascertain providers’ knowledge of acute oxygen therapy so that appropriate educational interventions are instituted for better delivery. There is no available validated instrument to assess knowledge of acute oxygen therapy. The study aimed to develop, validate and evaluate the test-retest reliability of a questionnaire to determine the doctors and nurses understanding of acute oxygen therapy.

Methods

This study involved the development of the questionnaire contents by a literature review, assessment of face validity (n = 5), content validity, using a panel of experts (n = 10), item analysis and test-retest reliability among a sample (n = 121) of doctors and nurses.

Results

Face validity indicated that the questionnaire was quick to complete (10–15 min), most items were easy to follow and comprehensible. The global content validity index (S-CVI) was 0.85. The test-retest reliability statistics showed a kappa coefficient of 0.546–0.897 (all P<0.001) and percentage agreement of 80–98.3% indicating high temporal stability in the target population. In total, 90% of the items fulfilled the reliability acceptance criteria. Item discrimination analysis showed that most questions were at an acceptable level. The final questionnaire included 37 item questions and eight sections.

Conclusion

The designed questionnaire is a reliable and valid tool for assessing knowledge of acute oxygen therapy among doctors and nurses.

Reducing hospital admissions for COPD: perspectives following the Christchurch Earthquake

The devastating 2011 earthquake in Christchurch destroyed or badly damaged healthcare infrastructure, including Christchurch Hospital. This forced change in management of exacerbations of chronic obstructive pulmonary disease (COPD), which until that point had frequently led to admission to hospital and focused attention on providing safe community options for care. This paper describes the process of understanding factors contributing to high admission frequency with exacerbations of COPD and also describes a process of change, predominantly to healthcare delivery systems and philosophies, and the subsequent outcomes. What became clear in understanding admissions with COPD to Christchurch Hospital was that the behaviour of the patient, in the context of exacerbations, and the subsequent response of the system to the patient, led to admission being the default option, in spite of low severity of the exacerbation itself. By altering systems' responses to exacerbations, with a linked care process between ambulances, community care and hospitals, we were able to safely reduce admissions for COPD, with a sustained overall reduction in bed-day occupancy for COPD of ~48%. We would encourage these discussions and changes to occur without the stimulus of an earthquake in your healthcare environment!

An audit of change in clinical practice: from oxygen-driven to air-driven nebulisers for prehospital patients with acute exacerbations of chronic obstructive pulmonary disease (AECOPD)

BACKGROUND

In developed countries, ambulances normally carry oxygen cylinders, but not compressed air. Treatment of acute exacerbations of chronic obstructive pulmonary disease (AECOPD) with oxygen-driven nebulisers can result in hypercapnia and acidosis. Attempts to avoid this have involved interrupted administration of oxygen. However, small battery-powered air nebulisers are now available. This study aims to compare the prehospital oxygen saturations and treatment of patients suffering from AECOPD before and after the introduction of air nebulisers.

METHODS

The oxygen saturations and treatment of 200 AECOPD patients before and 200 AECOPD patients after the introduction of air nebulisers were compared. Compliance with a target saturation of 88-92% was calculated.

RESULTS

The median final oxygen saturation was lower for the post-intervention category (94%) than the pre-intervention category (96%). There was an increase in air nebuliser use from 0 to 56% (P < 0.001) and a decrease in oxygen use from 100 to 71.5% (P < 0.001). There was a numerical increase in the proportion of patients arriving at hospital with oxygen saturations of 88-92% following introduction of the air nebulisers (24 vs 16.5%) and a decrease in patients arriving with high saturations (67.5 vs 76.5%). The likelihood of achieving the target oxygen saturations following introduction of air nebulisers increased (odds ratio 1.598; 95% confidence interval 0.974, 2.621).

CONCLUSION

The introduction of prehospital air nebulisers resulted in a reduction in oxygen therapy in patients with AECOPD and a lower median prehospital oxygen saturation. This study supports the use of air nebulisers in the prehospital setting.

Impact and prevention of severe exacerbations of COPD: a review of the evidence

Severe exacerbations of COPD, ie, those leading to hospitalization, have profound clinical implications for patients and significant economic consequences for society. The prevalence and burden of severe COPD exacerbations remain high, despite recognition of the importance of exacerbation prevention and the availability of new treatment options. Severe COPD exacerbations are associated with high mortality, have negative impact on quality of life, are linked to cardiovascular complications, and are a significant burden on the health-care system. This review identified risk factors that contribute to the development of severe exacerbations, treatment options (bronchodilators, antibiotics, corticosteroids [CSs], oxygen therapy, and ventilator support) to manage severe exacerbations, and strategies to prevent readmission to hospital. Risk factors that are amenable to change have been highlighted. A number of bronchodilators have demonstrated successful reduction in risk of severe exacerbations, including long-acting muscarinic antagonist or long-acting β₂-agonist mono- or combination therapies, in addition to vaccination, mucolytic and antibiotic therapy, and nonpharmacological interventions, such as pulmonary rehabilitation. Recognition of the importance of severe exacerbations is an essential step in improving outcomes for patients with COPD. Evidence-based approaches to prevent and manage severe exacerbations should be implemented as part of targeted strategies for disease management.

Management of acute hypercapnic respiratory failure

PURPOSE OF REVIEW

The objective of this article is to review the most recent literature regarding the management of acute hypercapnic respiratory failure (AHRF).

RECENT FINDINGS

In the field of AHRF management, noninvasive ventilation (NIV) has become the standard method of providing primary mechanical ventilator support. Recently, extracorporeal carbon dioxide removal (ECCO2R) devices have been proposed as new therapeutic option.

SUMMARY

NIV is an effective strategy in specific settings and in selected population with AHRF. To date, evidence on ECCO2R is based only on case reports and case-control trials. Although the preliminary results using ECCO2R to decrease the rate of NIV failure and to wean hypercapnic patients from invasive ventilation are remarkable; further randomized studies are needed to assess the effects of this technique on both short-term and long-term clinical outcomes.

Acute oxygen therapy: a review of prescribing and delivery practices

Oxygen is a commonly used drug in the clinical setting and like other drugs its use must be considered carefully. This is particularly true for those patients who are at risk of type II respiratory failure in whom the risk of hypercapnia is well established. In recent times, several international bodies have advocated for the prescription of oxygen therapy in an attempt to reduce this risk in vulnerable patient groups. Despite this guidance, published data have demonstrated that there has been poor uptake of these recommendations. Multiple interventions have been tested to improve concordance, and while some of these interventions show promise, the sustainability of these interventions are less convincing. In this review, we summarize data that have been published on the prevalence of oxygen prescription and the accurate and appropriate administration of this drug therapy. We also identify strategies that have shown promise in facilitating changes to oxygen prescription and delivery practice. There is a clear need to investigate the barriers, facilitators, and attitudes of clinicians in relation to the prescription of oxygen therapy in acute care. Interventions based on these findings then need to be designed and tested to facilitate the application of evidence-based guidelines to support sustained changes in practice, and ultimately improve patient care.

Assessing the use of initial oxygen therapy in chronic obstructive pulmonary disease patients: a retrospective audit of pre-hospital and hospital emergency management

BACKGROUND

Carbon dioxide retention in chronic obstructive pulmonary disease (COPD) exacerbations can be a complication of oxygen therapy. Current recommendations suggest an inspired oxygen level (FiO2 ) < 0.28, aiming for saturation (SpO2 ) of 88-92% until arterial blood gas analysis is available.

AIMS

This study aims to assess the use of O2 therapy and FiO2 in the emergency management of patients with a known diagnosis of COPD.

METHODS

Retrospective audit of 150 COPD patients admitted over 18 months, data being extracted from the hospital records.

RESULTS

Of the records reviewed, 57% were male, mean age 75 years. COPD was recognised in 53%. SpO2 recorded in 124 patients, with SpO2 < 88% seen in 40 patients. Oxygen was administered in 123 patients in ambulances; high flow in 111 patients, and only 12 patients received O2 therapy in line with the recommended FiO2 < 0.28. In the emergency department (ED), 112 patients received O2 supplementation; high flow given in 68 patients. Hypercapnia was seen in 71 patients; FiO2 > 0.28 given in 54 patients in ambulances and in 35 patients in ED. Non-invasive ventilation was required in 53 patients; FiO2 > 0.28 given in 29 patients in the ED. Seven patients were admitted to intensive care unit, and 10 patients died.

CONCLUSION

High-flow oxygen is used for the initial treatment of COPD exacerbations, but only 53% are recognised as having COPD. A FiO2 > 0.28 is often initiated before admission and continued in the ED. A larger study would be required to assess any possible harm of this approach, but education of those involved in the care of COPD patients may reduce the risk of complications of hypercapnia.

Analysis of the clinical backgrounds of patients who developed respiratory acidosis under high-flow oxygen therapy during emergency transport

Aim

High-flow oxygen is often administered to patients during emergency transport and can sometimes cause respiratory acidosis with disturbed consciousness, thereby necessitating mechanical ventilation. Although oxygen titration in chronic obstructive pulmonary disease patients during emergency transport reduces mortality rates, the clinical risk factors for respiratory acidosis in emergency settings are not fully understood. Therefore, we analyzed the clinical backgrounds of patients who developed respiratory acidosis during pre-hospital transport.

Methods

This was a retrospective study of patients who arrived at our hospital by emergency transport in 2010 who received high-flow oxygen while in transit. Respiratory acidosis was defined by the following arterial blood gas readings: pH, ≤7.35; PaCO ₂, ≥45 mmHg; and HCO ₃^-, ≥24 mmol/L. The risk factors were identified using multivariable logistic regression analysis.

Results

In 765 study patients, 66 patients showed respiratory acidosis. The following risk factors for respiratory acidosis were identified: age, ≥65 years (odds ratio [OR] 1.4; 95% confidence interval [CI], 0.7-2.8); transportation time, ≥10 min (OR 2.0; 95% CI, 1.1-3.7); three digits on the Japan Coma Scale (OR 3.1; 95% CI, 1.7-5.8); percutaneous oxygen saturation, ≤90% (OR 1.6; 95% CI, 0.8-3.0); tuberculosis (OR 4.5; 95% CI, 1.4-15.1); asthma (OR 1.8; 95% CI, 0.6-5.3); pneumonia (OR 1.5; 95% CI, 0.7-3.1); and lung cancer (OR 3.9; 95% CI, 1.5-10.1). These underlying diseases as risk factors included both comorbid diseases and past medical conditions.

Conclusions

The factors identified may contribute to the development of respiratory acidosis. Further studies on preventing respiratory acidosis will improve the quality of emergency medical care.

Outcomes of acute exacerbations in COPD in relation to pre-hospital oxygen therapy

BACKGROUND

Pre-hospital, high-concentration oxygen therapy during acute exacerbation of chronic obstructive pulmonary disease (AECOPD) has been associated with increased mortality. Recent COPD guidelines have encouraged titrated oxygen therapy with a target saturation range of 88-92%. Oxygen therapy leading to saturation above 92% is defined as 'inappropriate oxygen therapy'.

OBJECTIVES

To examine the frequency of inappropriate oxygen therapy and whether inappropriate oxygen therapy in the ambulance in an urban area with short transit time to hospital was associated with poor outcome.

METHODS

In an audit of 405 consecutive patients with AECOPD arriving by ambulance to Hvidovre Hospital, details of transit time, oxygen administration, saturation, and arterial blood gases were registered. Outcomes were respiratory acidosis, need of supported ventilation, length of hospitalisation, and in-hospital mortality.

RESULTS

Only 15 patients were not treated with oxygen and information on oxygen flow was missing in seven patients and on saturation on one patient. Altogether, 352 (88.7%) of 397 patients received inappropriate oxygen therapy. Patients on 'inappropriate oxygen therapy' (saturation ≥92%) had a high frequency of respiratory acidosis at hospital admission, 108 (33.5%) of 324 patients, length of stay was on average 5.1 days, 12.5% of the patients needed ventilatory support, and in-hospital mortality was 3.4%.

CONCLUSION

The majority of patients with AECOPD received inappropriate oxygen therapy in the ambulance, but their need of ventilatory support, length of stay, and mortality were low. Randomised studies are needed to clarify the optimal pre-hospital oxygen therapy.

Standards of suitability for the management of chronic obstructive respiratory diseases

BACKGROUND

Chronic Obstructive Pulmonary Disease (COPD) ranks third as cause of mortality and disability-adjusted life years (DALY) worldwide and also in Italy it imposes a huge health, social and economic load. Early symptoms of COPD are often disregarded by patients and physicians, spirometry is underutilized, and the diagnosis is delayed till the disease has reached a distinct severity level. Despite the availability of various guidelines, the behavior of health workers involved in the management of COPD is still rather unlike. These considerations are the reason why in October 2013 AIMAR (Interdisciplinary Scientific Association for Research in Lung Disease) devised and organized a "Third Consensus Conference", aimed at pointing out the standards of suitability for COPD management. In this context three important topics of discussion were identified: early and more widespread diagnosis, management of acute and subacute phases, long-term assistance to chronic patients.

METHODS

The procedure recommended by the Italian Health Superior Institute (ISS) for Consensus Conferences organization was applied. The Conference was structured in three sessions, each dealing with one of the above mentioned topics and including a short update of the subject-matter and presentation, discussion and voting of some statements with a choice ranging from total agreement to total disagreement or no knowledge. The results of voting were eventually recorded in the document, reviewed by an independent jury, that forms the substance of this paper.

RESULTS

The essential role of spirometry, the need for distinguish between different COPD phenotypes, and the obligatoriness to base on the blood gas analysis findings the long-term oxygen therapy, were largely agreed, as well as the need for interventions aimed at decreasing the rate of acute exacerbations. More specific topics like the use of noninvasive ventilation, recognizing the factors affecting outcome and mortality, the choice of pharmacological and non pharmacological treatments in COPD patients led to lively discussing, but they did not always reach the total agreement, probably because of insufficient familiarity with these problems and of diversities in organization and instruments availability. The chronic respiratory assistance was treated with particular regard to smoking cessation, whose implementation is still insufficient. Many doubts rose due to uncertainty, lack of ability and standardization of procedures, insufficient institutional support, and difficulties to realize a network for assistance to chronic patients.

CONCLUSIONS

The results of this Third Consensus Conference revealed some certainties and many doubts and diversities of view also on topics whose importance is well demonstrated in scientific literature. Thus, there is still a long distance to cover before reaching a suitable standardization of COPD management and such situation urges the need for improving not only the health professional's operativeness but also the organizational support by competent institutions. In this context some initiatives organized by AIMAR in cooperation with other respiratory scientific societies and patients' associations are going on.

How do health-care professionals perceive oxygen therapy? A critical interpretive synthesis of the literature

Oxygen is one of the commonest health-care interventions worldwide. This might suggest that health-care professionals (HCPs) would be knowledgeable and familiar with its uses and limitations. Yet it is apparent, through clinical audit, that oxygen is probably misunderstood by many HCPs. The aim of this critical interpretive synthesis (CIS) is to explore qualitative and quantitative literature in relation to HCPs beliefs and perceptions of oxygen therapy. A systematic search in Medline, Cinahl, Embase, British Nursing Index and PsychInfo using search terms, such as, oxygen therapy, chronic respiratory disease, HCPs and perceptions yielded 1514 studies of which 12 contained data relevant to the review question. Two reviewers independently screened the articles for eligibility against inclusion and exclusion criteria, and data were selected and synthesized with an integrative and interpretive approach using CIS. This allowed diverse empirical evidence to be synthesized to develop existing and new interpretations of data.Three synthetic constructs were interpreted from the available literature, namely, oxygen for symptom relief, levels of knowledge and understanding and oxygen as a therapy for HCPs. The literature alludes to deep-seated beliefs that exist. In order to enhance practice, these beliefs and cultures need to be challenged. Further research is needed to explore HCPs’ perceptions of oxygen therapy in order to inform the seemingly resistant adoption of evidence based practice in relation to oxygen.

Implementation of a titrated oxygen protocol in the out-of-hospital setting

Oxygen is one of the most frequently-used therapeutic agents in medicine and the most commonly administered drug by prehospital personnel. There is increasing evidence of harm with too much supplemental oxygen in certain conditions, including stroke, chronic obstructive pulmonary disease (COPD), neonatal resuscitations, and in postresuscitation care. Recent guidelines published by the British Thoracic Society (BTS) advocate titrated oxygen therapy, but these guidelines have not been widely adapted in the out-of-hospital setting where high-flow oxygen is the standard. This report is a description of the implementation of a titrated oxygen protocol in a large urban-suburban Emergency Medical Services (EMS) system and a discussion of the practical application of this out-of-hospital protocol.

Prevalence of prehospital hypoxemia and oxygen use in trauma patients

OBJECTIVE

This study estimates the prevalence of injured patients requiring prehospital supplemental oxygen based on existing recommendations, and determines whether actual use exceeds those recommendations.

PATIENTS AND METHODS

Prehospital oxygen use and continuous peripheral oxygen saturation measurements were prospectively collected on a purposive sample of injured civilians transported to an urban level 1 trauma center by paramedics. Structured chart review determined injury characteristics and outcomes. Supplemental oxygen administration indications were hypoxemia (peripheral oxygen saturation ≤ 90%), hemorrhagic shock (systolic blood pressure < 100 mmHg), or paramedic suspicion of traumatic brain injury.

RESULTS

Paramedics enrolled 224/290 screened subjects. Median (range) age was 34 (18-84) years, 48.7% were nonwhite, 75.4% were male, and Injury Severity Score was 5 (1-75). Half (54.5%) were admitted; 36.2% sustained a penetrating injury. None underwent prehospital endotracheal intubation. Hypoxemia occurred in 86 (38.4%), paramedics suspected traumatic brain injury in 22 (9.8%), and 20 (8.9%) were hypotensive. Any indication for supplemental oxygen (107/224 [47.8%, 95%CI 41.3%-54.3%]) and prehospital administration of oxygen (141/224 [62.9%, 95%CI 56.2%-69.2%]) was common. Many (35/141 [24.8%]) received oxygen without indication.

CONCLUSIONS

On the basis of current guidelines, less than half of adult trauma patients have an indication for prehospital supplemental oxygen, yet is frequently administered in the absence of clinical indication.

Optimal oxygen titration in patients with chronic obstructive pulmonary disease: a role for automated oxygen delivery?

Oxygen therapy can be life-saving for patients with chronic obstructive pulmonary disease (COPD) and is the backbone of any acute COPD treatment strategy. Although largely considered to be a benign drug, many publications have highlighted the need to accurately adjust oxygen delivery to avoid both hypoxemia and the problem of hyperoxia-induced hypercapnia. Recent clinical data have shown that the deleterious effects of excess oxygen treatment can not only alter carbon dioxide levels (which has been known for more than 60 years) but can also lead to an increase in mortality. Nevertheless, despite the extensive literature, the risks associated with hyperoxia are often overlooked and published clinical recommendations are largely ignored. This failure in knowledge translation has become increasingly important not only because of the desire to reduce medical error, but in a society with limited health care resources, the economic burden of COPD is such that it cannot afford to make preventable medical mistakes. Recently, novel devices have been developed to automatically adjust oxygen flow rates to maintain stable oxygen saturations. These closed-loop oxygen delivery systems have the potential to reduce medical error, improve morbidity and mortality, and reduce health care costs. Preliminary data in this field are promising and will require a significant amount of research in the coming years to determine the precise indications for these systems. The importance of appropriate oxygen dosing and the current literature regarding novel oxygen delivery systems are reviewed.

Hyperoxia is associated with increased mortality in patients treated with mild therapeutic hypothermia after sudden cardiac arrest

OBJECTIVE

To determine whether higher levels of PaO2 are associated with in-hospital mortality and poor neurological status at hospital discharge in patients treated with mild therapeutic hypothermia after sudden cardiac arrest.

DESIGN

Retrospective analysis of a prospective cohort.

PATIENTS

A total of 170 consecutive patients treated with therapeutic hypothermia in the cardiovascular care unit of an academic tertiary care hospital.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 170 patients, 77 (45.2%) survived to hospital discharge. Survivors had a significantly lower maximum PaO2 (198 mm Hg; interquartile range, 152.5-282) measured in the first 24 hrs following cardiac arrest compared to nonsurvivors (254 mm Hg; interquartile range, 172-363; p = .022). A multivariable analysis including age, time to return of spontaneous circulation, the presence of shock, bystander cardiopulmonary resuscitation, and initial rhythm revealed that higher levels of PaO2 were significantly associated with increased in-hospital mortality (odds ratio 1.439; 95% confidence interval 1.028-2.015; p = .034) and poor neurological status at hospital discharge (odds ratio 1.485; 95% confidence interval 1.032-2.136; p = .033).

CONCLUSIONS

Higher levels of the maximum measured PaO2 are associated with increased in-hospital mortality and poor neurological status on hospital discharge in patients treated with mild therapeutic hypothermia after sudden cardiac arrest.

Oxygen-induced hypercapnia in COPD: myths and facts

During our medical training, we learned that oxygen administration in patients with chronic obstructive pulmonary disease (COPD) induces hypercapnia through the 'hypoxic drive' mechanism and can be dangerous. This mindset frequently results in the reluctance of clinicians to administer oxygen to hypoxemic patients with COPD. However, this fear is not based on evidence in the literature. Here, we will review the impact and pathophysiology of oxygen-induced hypercapnia in patients with acute exacerbation of COPD and recommend a titrated oxygen management.

Perioperative oxygen toxicity

This article challenges the use of hyperoxia in the perioperative period. It describes the biochemical and physiologic basis for both the direct and indirect adverse effects of oxygen. The reasons for using hyperoxia in the perioperative period are critically evaluated, and the evidence and guidelines for oxygen use in common acute medical conditions are reviewed.