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

High flow oxygen and risk of mortality in patients with a suspected acute coronary syndrome: pragmatic, cluster randomised, crossover trial

OBJECTIVE

To determine the association between high flow supplementary oxygen and 30 day mortality in patients presenting with a suspected acute coronary syndrome (ACS).

DESIGN

Pragmatic, cluster randomised, crossover trial.

SETTING

Four geographical regions in New Zealand.

PARTICIPANTS

40 872 patients with suspected or confirmed ACS included in the All New Zealand Acute Coronary Syndrome Quality Improvement registry or ambulance ACS pathway during the study periods. 20 304 patients were managed using the high oxygen protocol and 20 568 were managed using the low oxygen protocol. Final diagnosis of ST elevation myocardial infarction (STEMI) and non-STEMI were determined from the registry and ICD-10 discharge codes.

INTERVENTIONS

The four geographical regions were randomly allocated to each of two oxygen protocols in six month blocks over two years. The high oxygen protocol recommended oxygen at 6-8 L/min by face mask for ischaemic symptoms or electrocardiographic changes, irrespective of the transcapillary oxygen saturation (SpO₂). The low oxygen protocol recommended oxygen only if SpO₂ was less than 90%, with a target SpO₂ of less than 95%.

MAIN OUTCOME MEASURE

30 day all cause mortality determined from linkage to administrative data.

RESULTS

Personal and clinical characteristics of patients managed under both oxygen protocols were well matched. For patients with suspected ACS, 30 day mortality for the high and low oxygen groups was 613 (3.0%) and 642 (3.1%), respectively (odds ratio 0.97, 95% confidence interval 0.86 to 1.08). For 4159 (10%) patients with STEMI, 30 day mortality for the high and low oxygen groups was 8.8% (n=178) and 10.6% (n=225), respectively (0.81, 0.66 to 1.00) and for 10 218 (25%) patients with non-STEMI was 3.6% (n=187) and 3.5% (n=176), respectively (1.05, 0.85 to 1.29).

CONCLUSION

In a large patient cohort presenting with suspected ACS, high flow oxygen was not associated with an increase or decrease in 30 day mortality.

TRIAL REGISTRATION

ANZ Clinical Trials ACTRN12616000461493.

[Oxygen Therapy in Lung Transplantation Candidates - A Single Center Retrospective Analysis of 807 Patients]

BACKGROUND

 Long-term oxygen treatment (LTOT) is frequently used in patients with advanced pulmonary diseases and respiratory failure. Oxygen treatment influences donor lung allocation for patients and is associated with increased mortality. This study investigates oxygen therapy in lung transplantation candidates.

METHODS

 A retrospective study at a large German transplantation centre between 09/2011 and 01/2019 was performed. Data regarding oxygen therapy was analyzed and LTOT-indication verified by titrated blood gas analysis. The study period splits into 2 periods before and after the introduction of oxygen titration (3rd quarter of 2015). Univariate and multivariate analysis for the endpoint "admission to waiting list" was performed.

RESULTS

 807 patients were included in the analysis, 396 in the first and 411 patients in the second period. Of those 293 patients (36.3 %) were transplanted. Six hundred thirty (78 %) patients stated using oxygen for more than 12 hours per day. After implementing oxygen titration in period 2, in 212 (57 %) of 372 patients LTOT indication could be confirmed. Titrated oxygen flow was lower in period 2 (0.5 l/min [IQR 0.0 - 2.0] versus 2 l/min [IQR 0.5 - 3.0]). In multivariate analysis oxygen flow was associated with admission to waiting list as an independent variable.

CONCLUSION

 Patients referred to lung transplantation use oxygen therapy in the vast majority. Indication for LTOT should be carefully reassessed in candidates. Confirmed LTOT-indication seems to be associated with the likelihood for admission to the waiting list for lung transplantation and could therefore be a selection criterium in the future.

Audit of oxygen administration to achieve a target oxygen saturation range in acutely unwell medical patients

PURPOSE OF THE STUDY

To evaluate documentation of a target oxygen saturation (SpO₂) range and ability to achieve this range in acutely unwell inpatients.

STUDY DESIGN

In this single-centre audit, patients with discharge diagnoses of pneumonia, heart failure and exacerbation of asthma or COPD admitted to Wellington Regional Hospital, New Zealand between 1 June 2019 and 31 August 2019 who received oxygen were identified. In those with a documented target SpO₂ range, the proportion of SpO₂ measurements in the observation chart which were within, above and below range were determined as well as the maximum and minimum SpO₂. Regression analysis was performed to determine whether these outcomes were influenced by the prescribed range, high-dependency care or the number of adjustments to oxygen administration.

RESULTS

268 admissions were screened. Of the 100 eligible admissions who received oxygen, a target SpO₂ range was documented in 62. The mean (SD) proportion of SpO₂ measurements within range was 56.2 (30.6)%. A hypercapnic target SpO₂ range was associated with a higher probability of an SpO₂ above range; multivariate OR 5.34 (95% CI 1.65 to 17.3, p=0.006) and a lower probability of an SpO₂ below range; multivariate OR 0.25 (95% CI 0.08 to 0.80) p=0.02. The mean (SD) maximum SpO₂ was similar in those with a target range of 92%-96% versus a hypercapnic range; 96.2 (3.0)% and 95.2 (3.4)%, respectively.

CONCLUSIONS

Oxygen prescription and delivery in this clinical setting was suboptimal. SpO₂ values above the designated range are common, particularly in patients with a hypercapnic target range.

Impact of Using a Non-Rebreathing Mask in Patients With Respiratory Failure

BACKGROUND

Liberal oxygen therapy might increase the mortality rate of patients. Non-rebreathing masks (NRM) are a high-flow, non-invasive oxygen device that can provide oxygen concentration up to 95%. This study aimed to determine the impact of using NRM in patients with respiratory failure.

METHODS

This retrospective cohort study was conducted in four medical institutions in Taiwan from January 2010 to December 2016. The association between mortality and NRM use before receiving ventilator support in patients with respiratory failure in the emergency department was analyzed. Patients were divided into the NRM treatment and no NRM treatment groups. A 1:4 propensity score matching was conducted. Regarding the duration of NRM use, treatments were grouped as 0 h, 0-1 h, 1-2 h, and >2 h.

RESULTS

A total of 18,749 patients were included, with 1074 using NRM. After propensity score matching, 1028 patients using NRM (0-1 h: 508, 1-2 h: 193, and >2 h: 327) and 4112 patients not using NRM were analyzed. The 30-day mortality rates were 29.1%, 28.5%, 27.5%, and 35.5% in the 0 h, 0-1 h, 1-2 h, and >2 h treatment groups, respectively. Patients with respiratory failure due to pulmonary disease using NRM over 2 h had a higher mortality rate than patients not using NRM (hazard ratio: 1.3, 95% CI: 1.01-1.66).

CONCLUSIONS

Prolonged use of NRM in patients with respiratory failure due to pulmonary disease possibly increases mortality.

Eradication success for non-tuberculous mycobacteria in children with cystic fibrosis

Non-tuberculous mycobacteria (NTM) are an emerging pathogen worldwide in both cystic fibrosis (CF) and non-CF pulmonary disease (PD), with reports suggesting an increasing prevalence [1, 2]. It is an opportunistic infection acquired from the environment [3], though conflicting evidence remains around person-to-person transmission [4, 5]. Recent evidence suggests that Mycobacterium abscessus complex (MABSC) may be the most detrimental airway infection to lung function in CF [6], yet its treatment remains poorly evidenced.

Non-tuberculous mycobacteria pulmonary disease affects cystic fibrosis lung health and increasingly affects children. This study reports treatment outcomes from a large CF centre, with eradication rates exceeding 60% for M. abscessus complex infection.https://bit.ly/2L8TdFM

Impact of body mass index on development of nontuberculous mycobacterial pulmonary disease

The incidence and prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) have been increasing worldwide. The risk of NTM-PD may be higher in undernourished populations. In this study, we tried to elucidate the impact of body mass index (BMI) and its change on development of NTM-PD.We performed a retrospective cohort study including South Koreans aged >40 years who underwent biennial National Health Insurance System (NHIS) health check-ups in both 2005 and 2009 or 2006 and 2010. We monitored eligible individuals from the study initiation date (NHIS health check-up date in 2009 or 2010) until the diagnosis of NTM-PD or until December 31, 2017. Enroled individuals were classified based on BMI at initiation date. By calculating hazard ratios, we compared NTM-PD incidence per 100 000 person-years by BMI group and by BMI change.A total of 5 670 229 individuals were included in the final analysis. Compared with the BMI <18.5 kg·m^-2 group, the incidence of NTM-PD gradually decreased with increased BMI (adjusted hazard ratio 0.38, 95% confidence interval (CI) 0.35-0.42 for BMI 18.5-22.9; 0.17, 95% CI 0.15-0.19 for BMI 23-24.9; 0.1, 95% CI 0.09-0.11 for BMI 25-29.9; and 0.1, 95% CI 0.07-0.13 for BMI ≥30). A BMI decrease of ≥1 kg·m^-2 over 4 years increased the incidence of NTM-PD (adjusted hazard ratio 1.08, 95% CI 1.01-1.16) whereas a BMI increase of ≥1 kg·m^-2 decreased the incidence of NTM-PD (adjusted hazard ratio 0.77, 95% CI 0.71-0.83).In conclusion, BMI was inversely related to development of NTM-PD and weight loss increased the risk of NTM-PD.

Prehospital continuous positive airway pressure for acute respiratory failure: the ACUTE feasibility RCT

BACKGROUND

Acute respiratory failure is a life-threatening emergency. Standard prehospital management involves controlled oxygen therapy. Continuous positive airway pressure is a potentially beneficial alternative treatment; however, it is uncertain whether or not this treatment could improve outcomes in NHS ambulance services.

OBJECTIVES

To assess the feasibility of a large-scale pragmatic trial and to update an existing economic model to determine cost-effectiveness and the value of further research.

DESIGN

(1) An open-label, individual patient randomised controlled external pilot trial. (2) Cost-effectiveness and value-of-information analyses, updating an existing economic model. (3) Ancillary substudies, comprising an acute respiratory failure incidence study, an acute respiratory failure diagnostic agreement study, clinicians perceptions of a continuous positive airway pressure mixed-methods study and an investigation of allocation concealment.

SETTING

Four West Midlands Ambulance Service hubs, recruiting between August 2017 and July 2018.

PARTICIPANTS

Adults with respiratory distress and peripheral oxygen saturations below the British Thoracic Society's target levels were included. Patients with limited potential to benefit from, or with contraindications to, continuous positive airway pressure were excluded.

INTERVENTIONS

Prehospital continuous positive airway pressure (O-Two system, O-Two Medical Technologies Inc., Brampton, ON, Canada) was compared with standard oxygen therapy, titrated to the British Thoracic Society's peripheral oxygen saturation targets. Interventions were provided in identical sealed boxes.

MAIN OUTCOME MEASURES

Feasibility objectives estimated the incidence of eligible patients, the proportion recruited and allocated to treatment appropriately, adherence to allocated treatment, and retention and data completeness. The primary clinical end point was 30-day mortality.

RESULTS

Seventy-seven patients were enrolled (target 120 patients), including seven patients with a diagnosis for which continuous positive airway pressure could be ineffective or harmful. Continuous positive airway pressure was fully delivered to 74% of participants (target 75%). There were no major protocol violations/non-compliances. Full data were available for all key outcomes (target ≥ 90%). Thirty-day mortality was 27.3%. Of the 21 deceased participants, 14 (68%) either did not have a respiratory condition or had ceiling-of-treatment decision implemented that excluded hospital non-invasive ventilation and critical care. The base-case economic evaluation indicated that standard oxygen therapy was probably cost-effective (incremental cost-effectiveness ratio £5685 per quality-adjusted life-year), but there was considerable uncertainty (population expected value of perfect information of £16.5M). Expected value of partial perfect information analyses indicated that effectiveness of prehospital continuous positive airway pressure was the only important variable. The incidence rate of acute respiratory failure was 17.4 (95% confidence interval 16.3 to 18.5) per 100,000 persons per year. There was moderate agreement between the primary prehospital and final hospital diagnoses (Gwet's AC1 coefficient 0.56, 95% confidence interval 0.43 to 0.69). Lack of hospital awareness of the Ambulance continuous positive airway pressure (CPAP): Use, Treatment Effect and economics (ACUTE) trial, limited time to complete trial training and a desire to provide continuous positive airway pressure treatment were highlighted as key challenges by participating clinicians.

LIMITATIONS

During week 10 of recruitment, the continuous positive airway pressure arm equipment boxes developed a 'rattle'. After repackaging and redistribution, no further concerns were noted. A total of 41.4% of ambulance service clinicians not participating in the ACUTE trial indicated a difference between the control and the intervention arm trial boxes (115/278); of these clinician 70.4% correctly identified box contents.

CONCLUSIONS

Recruitment rate was below target and feasibility was not demonstrated. The economic evaluation results suggested that a definitive trial could represent value for money. However, limited compliance with continuous positive airway pressure and difficulty in identifying patients who could benefit from continuous positive airway pressure indicate that prehospital continuous positive airway pressure is unlikely to materially reduce mortality.

FUTURE WORK

A definitive clinical effectiveness trial of continuous positive airway pressure in the NHS is not recommended.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN12048261.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 7. See the NIHR Journals Library website for further project information.

Pharmacological and nonpharmacological interventions to improve symptom control, functional exercise capacity and quality of life in interstitial lung disease: an evidence synthesis

We assessed efficacy and effectiveness of pharmacological and nonpharmacological interventions in improving symptom control, functional exercise capacity and quality of life (QoL) in people living with fibrotic interstitial lung disease (ILD). We summarised evidence from three previous reviews (to June 2014) and conducted an updated search of nine databases and grey literature (2011-2019) (registration: CRD42017065933) for prospective studies of interventions aimed to alleviate symptoms, improve QoL or functional exercise capacity in fibrotic ILD. Data were synthesised through narrative synthesis or meta-analysed as appropriate. Forty-seven studies with 2527 participants were included. From 22 pharmacological studies of 11 different interventions (n=1683), the most tested interventions were bosentan and sildenafil. From 25 nonpharmacological studies, the most tested intervention was for pulmonary rehabilitation/exercise training (PR) (22 studies, n=748). There was an improvement in 6-min walk distance immediately following PR (six studies; n=200, mean difference (MD) (95% CI) 39.9 m (18.2 to 61.5)), but not longer term (3 or 6 months, four studies; n=147, MD 5.3 m (-12.9 to 23.4). Multiple, varied outcome measures were used (e.g. 37 studies assessing dyspnoea used 10 different scales with a lack of reporting of rate of deterioration in outcomes). Evidence gap mapping highlighted the most and least researched symptoms, as dyspnoea and cough, respectively. This evidence synthesis highlights overwhelmingly that the most researched symptom is dyspnoea and the strongest evidence base is for short-term PR. The least researched symptom was cough. Research going forward must focus on prioritising and standardising meaningful outcomes and focussing interventions on neglected symptoms.

Intensivists' response to hyperoxemia in mechanical ventilation patients: The status quo and related factors

BACKGROUND

Due to the still sparse literature in China, the investigation of hyperoxemia management is required. Thus, we aim to conduct a retrospective study to provide more information about hyperoxemia management in intensive care unit (ICU) patients.

METHODS

We retrospectively screened the medical records of adult patients (age ≥18 years) who required mechanical ventilation (MV) ≥24 hours from January 1, 2018, to December 31, 2018. All arterial blood gas (ABG) tested during MV was retrieved, and MV settings were recorded. The median arterial partial pressure of oxygen (PaO₂) >120 mmHg (1 mmHg=0.133 kPa) was defined as mild to moderate hyperoxemia, and PaO₂ >300 mmHg as extreme hyperoxemia. Intensivists' response to hyperoxemia was assessed based on the reduction of fraction of inspired oxygen (FiO₂) within one hour after hyperoxemia was recorded. Multivariable logistic regression analysis was performed to determine the independent factors associated with the intensivists' response to hyperoxemia.

RESULTS

A total of 592 patients were finally analyzed. The median Acute Physiology and Chronic Health Evaluation II (APACHE II) score was 21 (15-26). The PaO₂, arterial oxygen saturation (SaO₂), FiO₂, and positive end expiratory pressure (PEEP) were 96.4 (74.0-126.0) mmHg, 97.8% (95.2%-99.1%), 0.4 (0.4-0.5), and 5 (3-6) cmH₂O, respectively. Totally 174 (29.39%) patients had PaO₂ >120 mmHg, and 19 (3.21%) patients had extreme hyperoxemia at PaO₂ >300 mmHg. In cases of mild to moderate hyperoxemia with FiO₂ ≤0.4, only 13 (2.20%) patients had a decrease in FiO₂ within one hour. The multivariable logistic regression analysis showed that a positive response was independently associated with FiO₂ (odds ratio [OR] 1.09, 95% confidence interval [CI] 1.06-1.12, P<0.001), PaO₂ (OR 1.01, 95% CI 1.00-1.01, P=0.002), and working shifts (OR 5.09, 95% CI 1.87-13.80, P=0.001).

CONCLUSIONS

Hyperoxemia occurs frequently and is neglected in most cases, particularly when mild to moderate hyperoxemia, hyperoxemia with lower FiO₂, hyperoxemia during night and middle-night shifts, or FiO₂ less likely to be decreased. Patients may be at a risk of oxygen toxicity because of the liberal oxygen strategy. Therefore, further research is needed to improve oxygen management for patients with MV in the ICUs.

What is important for people with nontuberculous mycobacterial disease? An EMBARC-ELF patient survey

Patients' experiences of NTM pulmonary disease highlight important and unmet needs for better pharmacological treatment and education of medical staff https://bit.ly/3mjrlwh.

Diagnosis and Management of Acute Respiratory Distress Syndrome in a Time of COVID-19

Acute respiratory distress syndrome (ARDS) remains a serious illness with significant morbidity and mortality, characterized by hypoxemic respiratory failure most commonly due to pneumonia, sepsis, and aspiration. Early and accurate diagnosis of ARDS depends upon clinical suspicion and chest imaging. Coronavirus disease 2019 (COVID-19) is an important novel cause of ARDS with a distinct time course, imaging and laboratory features from the time of SARS-CoV-2 infection to hypoxemic respiratory failure, which may allow diagnosis and management prior to or at earlier stages of ARDS. Treatment of ARDS remains largely supportive, and consists of incremental respiratory support (high flow nasal oxygen, non-invasive respiratory support, and invasive mechanical ventilation), and avoidance of iatrogenic complications, all of which improve clinical outcomes. COVID-19-associated ARDS is largely similar to other causes of ARDS with respect to pathology and respiratory physiology, and as such, COVID-19 patients with hypoxemic respiratory failure should typically be managed as other patients with ARDS. Non-invasive respiratory support may be beneficial in avoiding intubation in COVID-19 respiratory failure including mild ARDS, especially under conditions of resource constraints or to avoid overwhelming critical care resources. Compared to other causes of ARDS, medical therapies may improve outcomes in COVID-19-associated ARDS, such as dexamethasone and remdesivir. Future improved clinical outcomes in ARDS of all causes depends upon individual patient physiological and biological endotyping in order to improve accuracy and timeliness of diagnosis as well as optimal targeting of future therapies in the right patient at the right time in their disease.

The diagnostic accuracy of pre-hospital assessment of acute respiratory failure

Introduction:

Acute respiratory failure (ARF) is a common medical emergency. Pre-hospital management includes controlled oxygen therapy, supplemented by specific management options directed at the underlying disease. The aim of the current study was to characterise the accuracy of paramedic diagnostic assessment in acute respiratory failure.

Methods:

A nested diagnostic accuracy and agreement study comparing pre-hospital clinical impression to the final hospital discharge diagnosis was conducted as part of the ACUTE (Ambulance CPAP: Use, Treatment effect and Economics) trial. Adults with suspected ARF were recruited from the UK West Midlands Ambulance Service. The pre-hospital clinical impression of the recruiting ambulance service clinician was prospectively recorded and compared to the final hospital diagnosis at 30 days. Agreement between pre-hospital and hospital diagnostic assessments was evaluated using raw agreement and Gwets AC1 coefficient.

Results:

77 participants were included. Chronic obstructive pulmonary disease (32.9%) and lower respiratory tract infection (32.9%) were the most frequently suspected primary pre-hospital diagnoses for ARF, with secondary contributory conditions recorded in 36 patients (46.8%). There was moderate agreement between the primary pre-hospital and hospital diagnoses, with raw agreement of 58.5% and a Gwets AC1 coefficient of 0.56 (95% CI 0.43 to 0.69). In five cases, a non-respiratory final diagnosis was present, including: myocardial infarction, ruptured abdominal aortic aneurysm, liver failure and sepsis.

Conclusions:

Pre-hospital assessment of ARF is challenging, with limited accuracy compared to the final hospital diagnosis. A syndromic approach, providing general supportive care, rather than a specifically disease-orientated treatment strategy, is likely to be most appropriate for the pre-hospital environment.

Oxygen therapy and inpatient mortality in COPD exacerbation

BACKGROUND

In hospitalised patients with exacerbation of Chronic Obstructive Pulmonary Disease, European and British guidelines endorse oxygen target saturations of 88%-92%, with adjustment to 94%-98% if carbon dioxide levels are normal. We assessed the impact of admission oxygen saturation level and baseline carbon dioxide on inpatient mortality.

METHODS

Patients were identified from the prospective Dyspnoea, Eosinopenia, Consolidation, Acidaemia and Atrial Fibrillation (DECAF) derivation study (December 2008-June 2010) and the mixed methods DECAF validation study (January 2012 to May 2014). In six UK hospitals, of 2645 patients with COPD exacerbation, 1027 patients were in receipt of supplemental oxygen at admission. All had a clinical history of COPD and obstructive spirometry. These patients were subdivided into the following groups: admission oxygen saturations of 87% or less, 88%-92%, 93%-96% or 97%-100%. Inpatient mortality was calculated for each group and expressed as ORs. The DECAF score and National Early Warning Score 2 (excluding oxygen saturation) were used in binary logistic regression to adjust for baseline risk.

RESULTS

In patients with COPD receiving supplemental oxygen, oxygen saturations above 92% were associated with higher mortality and an adverse dose-response. Compared with the 88%-92% group, the adjusted risk of death (OR) in the 93%-96% and 97%-100% groups was 1.98 (95% CI 1.09 to 3.60, p=0.025) and 2.97 (95% CI 1.58 to 5.58, p=0.001). In the subgroup with normocapnia, the mortality signal remained significant in both the 93%-96% and 97%-100% groups.

CONCLUSIONS

Inpatient mortality was lowest in those with oxygen saturations of 88%-92%. Even modest elevations in oxygen saturations above this range (93%-96%) were associated with an increased risk of death. A similar mortality trend was seen in both patients with hypercapnia and normocapnia. This shows that the practice of setting different target saturations based on carbon dioxide levels is not justified. Treating all patients with COPD with target saturations of 88%-92% will simplify prescribing and should improve outcome.

TRIAL REGISTRATION NUMBER

UKCRN ID 14214.

Arterial oxygen pressure targets in critically ill patients: Analysis of a large ICU database

BACKGROUND

Providing supplemental oxygen is common in the management of critically ill patients, yet the optimal oxygen regimen remains unclear.

OBJECTIVES

To explore the optimal range of PaO₂ in critically ill patients.

METHODS

This is a retrospective study conducted in the Medical Information Mart for Intensive Care III (MIMIC-III) database. The patients with a least 48 h of oxygen therapy were included. Nonlinear regression was used to analyze the association between PaO₂ and mortality. We derived an optimal range of PaO₂ and evaluated the association between the proportion of PaO₂ measurements within this range and mortality.

RESULTS

In total, 8401 patients were included in the study. A J-shaped relationship was observed between median PaO₂ and hospital mortality. Compared with the reference group of 100-120 mmHg, patients with values of 80-100 mmHg and 120-140 mmHg had higher hospital mortality (adjusted odds ratio [aOR], 1.23; 95% CI, 1.05-1.43 and 1.29; 95%CI, 1.08-1.54, respectively). Similarly, mortality rates were significantly higher for PaO₂ <80 mmHg and ≥140 mmHg (aOR, 1.97; 95%CI, 1.58-2.45 and 1.42; 95%CI, 1.19-1.69, respectively). Patients spent a greater proportion of time within 100-120 mmHg tended to have a lower mortality rate.

CONCLUSION

Among critically ill patients, the relationship between median PaO₂ and hospital mortality was J-shaped. The lowest rates of mortality was observed in those with PaO₂ levels within 100 to 120 mmHg.

Quality of smoking cessation advice in guidelines of tobacco-related diseases: An updated systematic review

Tobacco smoking is a major risk factor for a wide range of diseases, and smoking cessation significantly reduces these risks. Clinical guidelines for diseases associated with smoking should therefore include guidance on smoking cessation. This review updated evidence on the proportion of clinical guidelines that do so. We conducted a systematic review investigating clinical guidelines and recommendations developed by UK national or European transnational medical specialty associations and societies between January 2014 and October 2019 on 16 diseases to be at least twice as common among smokers than non-smokers. Outcomes of interest were the reporting of smoking as a risk factor, and the inclusion either of smoking cessation advice or referral to other cessation guidance. We compared our findings with an earlier review of guidelines published between 2000 and 2013. We identified 159 clinical guidelines/recommendations. Over half (51%) made no mention of smoking, while 43% reported smoking as a risk factor for the development of the disease, 31% recommended smoking cessation and 19% provided detailed information on how to deliver smoking cessation support. These proportions were similar to those in our earlier review. Smoking cessation continues to be neglected in clinical management guidance for diseases caused by smoking.

A Rapid Shift from Chronic Hyperoxia to Normoxia Induces Systemic Anaphylaxis via Transient Receptor Potential Ankyrin 1 Channels on Mast Cells

Extensive activation of mast cells is the major switch that triggers systemic anaphylaxis, resulting in the subsequent release of anaphylactic mediators into circulation. We previously demonstrated that rapid changes in oxygen tension lead to mast cell degranulation, and the released tryptase triggers retinal angiogenesis in a murine oxygen-induced retinopathy model. However, whether a rapid shift from hyperoxia to normoxia (relative hypoxic stress) is a risk factor for systemic anaphylaxis remains unknown. In this study, we demonstrated that the relative hypoxia stress induces systemic mast cell activation via transient receptor potential ankyrin 1 (TRPA1) channels, which immediately leads to hypothermia and increased vascular permeability in adult mice. Although mast cell-deficient or TRPA1-deficient mice did not exhibit anaphylactic symptoms following a rapid sift to normoxia, preinjection with bone marrow-derived cultured mast cells (BMCMCs) derived from wild-type TRPA1-expressing mice restored anaphylactic responses. In addition, we found that the rapid reductions in oxygen tension in a culture atmosphere triggered the degranulation of BMCMCs derived from wild-type TRPA1-expressing mice but not that of BMCMCs derived from TRPA1-deficient mice. In human LAD2 mast cells, the relative hypoxic stress led to the degranulation, which was suppressed by the addition of a TRPA1 inhibitor. Gradual reductions from hyperoxia to normoxia led to no anaphylactic symptoms. Our results demonstrated that TRPA1-triggered mast cell degranulation is a novel pathway that induces anaphylactic shock without Ag-Ab reactions. These findings introduce a potential role for oxygen in inducing mast cell-dependent anaphylaxis and highlight the need to reconsider chronic pure oxygen therapy for anoxic diseases.

Understanding Clinicians' Perceived Barriers and Facilitators to Optimal Use of Acute Oxygen Therapy in Adults

Background

Supplemental oxygen is commonly administered to patients in acute care. It may cause harm when used inappropriately. Guidelines recommend prescription of acute oxygen, yet adherence is poor. We aimed to identify barriers and facilitators to practicing in accordance with the evidence-based Thoracic Society of Australia and New Zealand (TSANZ) oxygen guideline, and to determine the beliefs and attitudes relating to acute oxygen therapy.

Methods

A national cross-sectional survey was conducted. The survey consisted of 3 sections: (1) introduction and participant characteristics; (2) opinion/beliefs, knowledge and actions about oxygen therapy and other drugs; and (3) barriers and facilitators to use of the TSANZ guideline. Convenience sampling was employed. A paper-based survey was distributed at the TSANZ Annual Scientific Meeting. An online survey was emailed to the TSANZ membership and to John Hunter Hospital's clinical staff.

Results

Responses were received from 133 clinicians: 52.6% nurses, 30.1% doctors, and 17.3% other clinicians. Over a third (37.7%) were unaware/unsure of the oxygen guideline's existence. Most (79.8%) believe that oxygen is a drug and should be treated as one. Most (92.4%) stated they only administered it based on clinical need. For four hypothetical cases, there was only one where the majority of participants identified the optimal oxygen saturation. A number of barriers and facilitators were identified when asked about practicing in accordance with the TSANZ guideline. Lack of oxygen equipment, getting doctors to prescribe oxygen and oxygen being treated differently to other drugs were seen as barriers. The guideline itself and multiple clinician characteristics were considered facilitators.

Conclusion

There is discordance between clinicians' beliefs and actions regarding the administration of oxygen therapy and knowledge gaps about optimal oxygen therapy in acute care. Identified barriers and facilitators should be considered when developing evidence-based guidelines to improve dissemination and knowledge exchange.

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

BACKGROUND

Approximately 14% of UK hospital in-patients receive supplemental oxygen therapy, only 57% have valid prescriptions. Oxygen must be optimally prescribed to ensure maximal therapeutic response whilst minimizing adverse outcomes (including fatality). This study investigates prescription compliance.

METHODS

All adults admitted to medical wards (18 February to 3 March 2020) were included. Analyses present proportions, descriptive statistics, and hypothesis testing. Ethical approval was unnecessary for this audit.

RESULTS

Of the 636 patients admitted, 66 (10%) were receiving oxygen therapy. Ages ranged from 34 to 100 years with 36 (54.5%) males and 30 (45.5%) females. The prescription was not documented in the oxygen section of the drug chart (n = 37, 56.1%, p = 0.389), nor did it have the physicians signature (n = 40, 60.6%, p = 0.110) nor date (n = 46, 69.7%, p = 0.002). Thirteen chronic obstructive pulmonary disease (COPD) patients (19.7%) were at risk of hypercapnic failure (p = 1.582x10^-6). Target oxygen saturation (SpO2) range had been documented for 30 (45.5%) patients. A target SpO2 range of 88-92% was documented for 9 patients (13.6%), a 94-98% range documented for 11 patients (16.7%). All patients had an invalid prescription.

CONCLUSION

We present real-world practice in naturalistic settings, immediately before pandemic-lockdown. Enhanced compliance is advocated to reduce risks of harm and mortality.

Automatic oxygen titration with O2matic® to patients admitted with COVID-19 and hypoxemic respiratory failure

Introduction

Patients with coronavirus disease (COVID-19) and pneumonitis often have hypoxemic respiratory failure and a need of supplementary oxygen. Guidelines recommend controlled oxygen, for most patients with a recommended interval of SpO₂ between 92 and 96%. We aimed to determine if closed-loop control of oxygen was feasible in patients with COVID-19 and could maintain SpO₂ in the specified interval.

Methods

Patients were prospectively enrolled in an observational study on a medical ward dedicated to patients with COVID-19. Closed-loop controlled oxygen was delivered by O2matic® which can deliver 0-15 liters/min and adjusts flow every second based on 15 seconds averaging of SpO₂ measured by pulse oximetry. Lung function parameters were measured at admission.

Results

Fifteen patients (six women, nine men) participated in the study. Average age was 72 years. Lung function was severely impaired with FEV₁, FVC and PEF reduced to approximately 50%. The average stay on the ward was 3.2 days and O2matic was used on average for 66 hours, providing 987 hours of observation. O2matic maintained SpO₂ in the desired interval for 82.9% of the time. Time with SpO₂ > 2% below interval was 5.1% and time with SpO₂ > 2% above interval was 0.6%.

Conclusion

Closed-loop control of oxygen to patients with COVID-19 is feasible and can maintain SpO₂ in the specified interval in the majority of time. Closed-loop automated control could be of particular benefit for patients in isolation with decreased visibility, surveillance and monitoring. Further studies must examine the clinical benefits.

Identification of potentially undiagnosed patients with nontuberculous mycobacterial lung disease using machine learning applied to primary care data in the UK

Nontuberculous mycobacterial lung disease (NTMLD) is a rare lung disease often missed due to a low index of suspicion and unspecific clinical presentation. This retrospective study was designed to characterise the prediagnosis features of NTMLD patients in primary care and to assess the feasibility of using machine learning to identify undiagnosed NTMLD patients.IQVIA Medical Research Data (incorporating THIN, a Cegedim Database), a UK electronic medical records primary care database was used. NTMLD patients were identified between 2003 and 2017 by diagnosis in primary or secondary care or record of NTMLD treatment regimen. Risk factors and treatments were extracted in the prediagnosis period, guided by literature and expert clinical opinion. The control population was enriched to have at least one of these features.741 NTMLD and 112 784 control patients were selected. Annual prevalence rates of NTMLD from 2006 to 2016 increased from 2.7 to 5.1 per 100 000. The most common pre-existing diagnoses and treatments for NTMLD patients were COPD and asthma and penicillin, macrolides and inhaled corticosteroids. Compared to random testing, machine learning improved detection of patients with NTMLD by almost a thousand-fold with AUC of 0.94. The total prevalence of diagnosed and undiagnosed cases of NTMLD in 2016 was estimated to range between 9 and 16 per 100 000.This study supports the feasibility of machine learning applied to primary care data to screen for undiagnosed NTMLD patients, with results indicating that there may be a substantial number of undiagnosed cases of NTMLD in the UK.

The "Just Right" Amount of Oxygen. Improving Oxygen Use in a Rwandan Emergency Department

Rationale: Despite oxygen's classification as an essential medication by the World Health Organization, it is inconsistently available in many resource-constrained settings. Hypoxemia is associated with increased mortality, and mounting evidence suggests that hyperoxia may also be associated with adverse outcomes.Objectives: To determine if overuse of oxygen for some patients in a Rwandan tertiary care hospital emergency department might coexist with oxygen shortages and underuse of oxygen for other patients, and whether an educational intervention coupled with provision of pulse oximeters could improve the distribution of limited oxygen resources.Methods: We screened all patients in the adult emergency department (ED) of the University Teaching Hospital of Kigali for hypoxemia and receipt of oxygen therapy for 5 weeks. After completing baseline data collection, we provided pulse oximeters and conducted a didactic training with pre- and posttests on oxygen titration, with a chosen target oxygen saturation (Sp_O2) of 90% to 95%. Four and 12 weeks after the intervention, we evaluated all patients in the ED again for Sp_O2 and receipt of oxygen therapy for 4 weeks each period. We also recorded ED oxygen use and availability of reserve oxygen for the hospital during the three study periods.Results: During all data collection periods, 214 of 1,765 (12.1%) unique patients screened were hypoxemic. The proportion of patient-days with appropriately titrated oxygen therapy (Sp_O2, 90-95%) increased from 18.7% at baseline to 38.5% and 42.0% at 4 and 12 weeks postintervention (P < 0.001). On a multiple-choice examination testing knowledge of appropriate oxygen titration, clinicians' scores improved from average 60% (interquartile range [IQR], 40-80%) correct to 80% (IQR, 60-80%) correct immediately after the educational intervention (P < 0.001). Oxygen use in the ED decreased from a median of 32.0 (IQR, 28.0-35.0) tanks per day to 25.5 (IQR, 24.0-29.0) and 16.0 (IQR, 12.5-21.0) tanks per day at Weeks 4 and 12, respectively (P < 0.001), and the median daily number of tanks in reserve for the hospital appeared to increase, although this did not reach statistical significance (30.0 [IQR, 9.0-46.0], 86.5 [IQR, 74.0-92.0], and 75.5 [IQR, 8.5-88.5], respectively; P = 0.07).Conclusions: Among patients in a Rwandan adult ED, 12.1% of patients were hypoxemic and 81.3% of patient-days were either under- or overtreated with oxygen during baseline data collection on the basis of our defined target of Sp_O2 90% to 95%. Follow-up results at 4 and 12 weeks postintervention demonstrated sustained improvement in oxygen titration and likely increased availability of oxygen resources.

Understanding Clinicians' Perceived Barriers and Facilitators to Optimal Use of Acute Oxygen Therapy in Adults

Background

Supplemental oxygen is commonly administered to patients in acute care. It may cause harm when used inappropriately. Guidelines recommend prescription of acute oxygen, yet adherence is poor. We aimed to identify barriers and facilitators to practicing in accordance with the evidence-based Thoracic Society of Australia and New Zealand (TSANZ) oxygen guideline, and to determine the beliefs and attitudes relating to acute oxygen therapy.

Methods

A national cross-sectional survey was conducted. The survey consisted of 3 sections: (1) introduction and participant characteristics; (2) opinion/beliefs, knowledge and actions about oxygen therapy and other drugs; and (3) barriers and facilitators to use of the TSANZ guideline. Convenience sampling was employed. A paper-based survey was distributed at the TSANZ Annual Scientific Meeting. An online survey was emailed to the TSANZ membership and to John Hunter Hospital's clinical staff.

Results

Responses were received from 133 clinicians: 52.6% nurses, 30.1% doctors, and 17.3% other clinicians. Over a third (37.7%) were unaware/unsure of the oxygen guideline's existence. Most (79.8%) believe that oxygen is a drug and should be treated as one. Most (92.4%) stated they only administered it based on clinical need. For four hypothetical cases, there was only one where the majority of participants identified the optimal oxygen saturation. A number of barriers and facilitators were identified when asked about practicing in accordance with the TSANZ guideline. Lack of oxygen equipment, getting doctors to prescribe oxygen and oxygen being treated differently to other drugs were seen as barriers. The guideline itself and multiple clinician characteristics were considered facilitators.

Conclusion

There is discordance between clinicians' beliefs and actions regarding the administration of oxygen therapy and knowledge gaps about optimal oxygen therapy in acute care. Identified barriers and facilitators should be considered when developing evidence-based guidelines to improve dissemination and knowledge exchange.

Abnormal Exercise Responses in Survivors of Acute Lung Injury During Cardiopulmonary Exercise Testing: AN OBSERVATIONAL STUDY

PURPOSE

This study compared exercise responses in individuals who had recently survived an admission to the intensive care unit for acute lung injury (ALI) with healthy controls.

METHODS

Ten patients with ALI were recruited at 2 Australian hospitals. Six weeks after hospital discharge, participants completed lung function measures and a laboratory-based cardiopulmonary exercise test. Identical measures were collected in 21 healthy participants of similar age and gender distribution.

RESULTS

Compared with the healthy participants, the ALI participants were similar in age (51 ± 14 vs 50 ± 16 yr), with a lower peak oxygen uptake ((Equation is included in full-text article.)O2) (median [interquartile range], 31.80 [26.60-41.73] vs 17.80 [14.85-20.85] mL/kg/min; P < .01) and higher ventilatory equivalent for carbon dioxide ((Equation is included in full-text article.)E/(Equation is included in full-text article.)CO2) at anaerobic threshold (mean ± SD, 25.7 ± 2.5 vs 35.2 ± 4.1; P < .01). Analysis of individual ALI participant responses showed that 8 participants had a decreased peak (Equation is included in full-text article.)O2 and anaerobic threshold. All ALI participants were limited by leg fatigue. Abnormalities of pulmonary gas exchange were present in 7 participants. Evidence of cardiac ischemia was present in 2 participants.

CONCLUSIONS

Compared with healthy controls, ALI participants had reduced exercise capacity, mainly due to profound deconditioning. Exercise training to optimize aerobic capacity would appear to be a rehabilitation priority in this population.

Compression asphyxia and other clinicopathological findings from the Hillsborough Stadium disaster

Ninety-six people died following a crowd crush at the Hillsborough Football Stadium, Sheffield, UK in 1989. The cause of death in nearly all cases was compression asphyxia. The clinical and pathological features of deaths encountered in crowds are discussed with a particular focus on the Hillsborough disaster.

The management of coronavirus disease 2019 (COVID-19)

In December 2019, a novel coronavirus causing severe acute respiratory disease occurred in Wuhan, China. It is an emerging infectious disease with widespread and rapid infectiousness. The World Health Organization declared the coronavirus outbreak to be a public health emergency of international concern on 31 January 2020. Severe COVID-19 patients should be managed and treated in a critical care unit. Performing a chest X-ray/CT can judge the severity of the disease. The management of COVID-19 patients includes epidemiological risk and patient isolation; treatment entails general supportive care, respiratory support, symptomatic treatment, nutritional support, psychological intervention, etc. The prognosis of the patients depends upon the severity of the disease, the patient's age, the underlying diseases of the patients, and the patient's overall medical condition. The management of COVID-19 should focus on early diagnosis, immediate isolation, general and optimized supportive care, and infection prevention and control.

Automated closed-loop versus standard manual oxygen administration after major abdominal or thoracic surgery: an international multicentre randomised controlled study

Introduction

Hypoxaemia and hyperoxaemia may occur after surgery, with related complications. This multicentre randomised trial evaluated the impact of automated closed-loop oxygen administration after high-risk abdominal or thoracic surgeries in terms of optimising the oxygen saturation measured by pulse oximetry time within target range.

Methods

After extubation, patients with an intermediate to high risk of post-operative pulmonary complications were randomised to “standard” or “automated” closed-loop oxygen administration. The primary outcome was the percentage of time within the oxygenation range, during a 3-day frame. The secondary outcomes were the time with hypoxaemia and hyperoxaemia under oxygen.

Results

Among the 200 patients, time within range was higher in the automated group, both initially (≤3 h; 91.4±13.7% versus 40.2±35.1% of time, difference +51.0% (95% CI −42.8–59.2%); p<0.0001) and during the 3-day period (94.0±11.3% versus 62.1±23.3% of time, difference +31.9% (95% CI 26.3–37.4%); p<0.0001). Periods of hypoxaemia were reduced in the automated group (≤3 days; 32.6±57.8 min (1.2±1.9%) versus 370.5±594.3 min (5.0±11.2%), difference −10.2% (95% CI −13.9–−6.6%); p<0.0001), as well as hyperoxaemia under oxygen (≤3 days; 5.1±10.9 min (4.8±11.2%) versus 177.9±277.2 min (27.0±23.8%), difference −22.0% (95% CI −27.6–−16.4%); p<0.0001). Kaplan–Meier analysis depicted a significant difference in terms of hypoxaemia (p=0.01) and severe hypoxaemia (p=0.0003) occurrence between groups in favour of the automated group. 25 patients experienced hypoxaemia for >10% of the entire monitoring time during the 3 days within the standard group, as compared to the automated group (p<0.0001).

Conclusion

Automated closed-loop oxygen administration promotes greater time within the oxygenation target, as compared to standard manual administration, thus reducing the occurrence of hypoxaemia and hyperoxaemia.

Oxygen therapy practices in the acutely ill medical patients: A social media-based nationwide study of clinicians’ preferences and summary of current recommendations

Oxygen is the most commonly used drug in emergency medicine. The aim of this study was to identify healthcare professionals’ preferences regarding oxygen therapy in common medical emergencies. An online 9-part-questionnaire was distributed through Facebook to doctors and nurses working in Greek hospitals. The questionnaire included background information of the respondents and addressed individual preferences regarding best oxygenation parameter and oxygen targets in specific acute settings. We received 678 responses and we included 663 in our analysis. We found significant differences between doctors’ and nurses’ attitudes towards oxygenation targets in ARDS, sepsis, acute coronary syndrome, and post cardiac-arrest patients. Nurses preferred a more conservative oxygen strategy compared to doctors. Furthermore, nurses favor SaO2 as the best oxygenation parameter, while doctors prefer PaO2. In our survey, the type of hospital and department of the respondents did not affect the preferred oxygen strategy. Social media-based survey research is feasible and effective. In this single country study, doctors showed a tendency to liberally administer oxygen in acutely ill medical patients. On the other hand, Greek nurses preferred a more conservative approach.

Investigating Disturbances of Oxygen Homeostasis: From Cellular Mechanisms to the Clinical Practice

Soon after its discovery in the 18th century, oxygen was applied as a therapeutic agent to treat severely ill patients. Lack of oxygen, commonly termed as hypoxia, is frequently encountered in different disease states and is detrimental to human life. However, at the end of the 19th century, Paul Bert and James Lorrain Smith identified what is known as oxygen toxicity. The molecular basis of this phenomenon is oxygen's readiness to accept electrons and to form different variants of aggressive radicals that interfere with normal cell functions. The human body has evolved to maintain oxygen homeostasis by different molecular systems that are either activated in the case of oxygen under-supply, or to scavenge and to transform oxygen radicals when excess amounts are encountered. Research has provided insights into cellular mechanisms of oxygen homeostasis and is still called upon in order to better understand related diseases. Oxygen therapy is one of the prime clinical interventions, as it is life saving, readily available, easy to apply and economically affordable. However, the current state of research also implicates a reconsidering of the liberal application of oxygen causing hyperoxia. Increasing evidence from preclinical and clinical studies suggest detrimental outcomes as a consequence of liberal oxygen therapy. In this review, we summarize concepts of cellular mechanisms regarding different forms of disturbed cellular oxygen homeostasis that may help to better define safe clinical application of oxygen therapy.

Nonantibiotic Pharmacological Treatment of Severe Chronic Obstructive Pulmonary Disease Exacerbations

Severe, acute exacerbations of chronic obstructive pulmonary disease (AECOPD) are a rapid deterioration of the respiratory symptoms of patients with COPD, requiring hospital admission and escalation of pharmacological and nonpharmacological care including the more severe cases of respiratory failure and admission to an intensive care unit (ICU). These events severely impact patients' quality of life and prognosis. This review will describe the nonantibiotic, pharmacological treatment options available for critically ill patients with AECOPD. The aim of treatment is to alleviate symptoms, improve patient's functional and respiratory status, reduce mortality, reduce the risk or the duration of invasive mechanical ventilation, and prevent reexacerbations. Inhaled bronchodilators (i.e., short-acting β2-agonists and anticholinergics) and systemic corticosteroids are the main drugs used in the treatment of AECOPD. These drugs are also used in the treatment of stable COPD and in the treatment of AECOPD patients in the non-ICU or community setting. Other drugs are essentially only used in the ICU setting such as inhaled anesthetic agents, ketamine, intravenous methylxanthines, and magnesium. Finally, recently developed drugs, such as the specific phosphodiesterase-4 inhibitors, may play a role in the prevention of relapsing AECOPD following a critical event than the treatment of the exacerbation itself. Although they significantly improve the survival of critically ill patients with AECOPD, none of available drugs, alone or combined, is able to significantly modify the prognosis of patients with COPD. This remains an open challenge for the current and future generations of researchers and clinicians.

Is a definitive trial of prehospital continuous positive airway pressure versus standard oxygen therapy for acute respiratory failure indicated? The ACUTE pilot randomised controlled trial

OBJECTIVES

To determine the feasibility of a large-scale definitive multicentre trial of prehospital continuous positive airway pressure (CPAP) in acute respiratory failure.

DESIGN

A single-centre, open-label, individual patient randomised, controlled, external pilot trial.

SETTING

A single UK Ambulance Service, between August 2017 and July 2018.

PARTICIPANTS

Adults with respiratory distress and peripheral oxygen saturations below British Thoracic Society target levels despite controlled oxygen treatment.

INTERVENTIONS

Patients were randomised to prehospital CPAP (O-Two system) versus standard oxygen therapy in a 1:1 ratio using simple randomisation.

PRIMARY AND SECONDARY OUTCOME MEASURES

Feasibility outcomes comprised recruitment rate, adherence to allocated treatment, retention and data completeness. The primary clinical outcome was 30-day mortality.

RESULTS

77 patients were enrolled (target 120), including 7 cases with a diagnosis where CPAP could be ineffective or harmful. CPAP was fully delivered in 74% (target 75%). There were no major protocol violations. Full data were available for all key outcomes (targets ≥90%). Overall 30-day mortality was 27.3%. Of these deceased patients, 14/21 (68%) either did not have a respiratory condition or had ceiling of treatment decisions implemented excluding hospital non-invasive ventilation and critical care.

CONCLUSIONS

Recruitment rate was below target and feasibility was not demonstrated. Limited compliance with CPAP, and difficulty in identifying patients who could benefit from CPAP, indicate that prehospital CPAP is unlikely to materially reduce mortality. A definitive effectiveness trial of CPAP is therefore not recommended.

TRIAL REGISTRATION NUMBER

ISRCTN12048261; Post-results.

The concept of peri-operative medicine to prevent major adverse events and improve outcome in surgical patients: A narrative review

: Peri-operative Medicine is the patient-centred and value-based multidisciplinary peri-operative care of surgical patients. Peri-operative stress, that is the collective response to stimuli occurring before, during and after surgery, is, together with pre-existing comorbidities, the pathophysiological basis of major adverse events. The ultimate goal of Peri-operative Medicine is to promote high quality recovery after surgery. Clinical scores and/or biomarkers should be used to identify patients at high risk of developing major adverse events throughout the peri-operative period. Allocation of high-risk patients to specific care pathways with peri-operative organ protection, close surveillance and specific early interventions is likely to improve patient-relevant outcomes, such as disability, health-related quality of life and mortality.

Current and future management of non-tuberculous mycobacterial pulmonary disease (NTM-PD) in the UK

A rising number of non-tuberculous mycobacterial (NTM) isolates are being identified in UK clinical practice. There are many uncertainties around the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD), including its epidemiology, diagnosis, treatment and prevention. Regional variations in how patients with NTM-PD are managed reflects the lack of standardised pathways in the UK. Service optimisation and multidisciplinary working can improve the quality of care for patients with NTM-PD, including (1) better identification of patients at risk of NTM-PD and modification of risk factors where applicable; (2) standardisation of reference laboratory testing to offer clinicians access to accurate and prompt information on NTM species and drug sensitivities; (3) development of recognised specialist NTM nursing care; (4) standardisation of NTM-PD imaging strategies for monitoring of treatment and disease progression; (5) establishment of a hub-and-spoke model of care, including clear referral and management pathways, dedicated NTM-PD multidisciplinary teams, and long-term patient follow-up; (6) formation of clinical networks to link experts who manage diseases associated with NTM; (7) enabling patients to access relevant support groups that can provide information and support for their condition; and (8) development of NTM research groups to allow patient participation in clinical trials and to facilitate professional education.

Do nursing textbooks accurately describe pulse oximetry? An audit of current literature

BACKGROUND

The assessment of a patient's vital signs is a critical nursing task. Despite this, research has found that many nurses have a poor understanding of pulse oximetry.

AIM

As undergraduate students rely heavily on textbooks as an educational resource, an audit was conducted of nursing texts to determine the quality of pulse oximetry descriptions.

METHOD

The audit was guided by questions based on the findings of research examining nurses' understanding of pulse oximetry. Two researchers used these questions to appraise textbook content.

FINDINGS

A convenience sample of 32 contemporary nursing textbooks was appraised. Text descriptions of pulse oximetry varied from brief to more extensive, with the content ranging from superficial to detailed.

CONCLUSION

Superficial, inconsistent or misleading information within basic nursing textbooks may be one factor associated with nurses' knowledge deficits about pulse oximetry. Academics and nurse educators should appraise core content of textbooks carefully before recommending textbooks to nursing students.

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.

Frequency of hyperoxaemia during and after major surgery

The oxygen concentration (FiO₂) and arterial oxygen tension (PaO₂) delivered in patients undergoing major surgery is poorly understood. We aimed to assess current practice with regard to the delivered FiO₂ and the resulting PaO₂ in patients undergoing major surgery. We performed a retrospective cohort study in a tertiary hospital. Data were collected prospectively as part of a larger randomised controlled trial but were analysed retrospectively. Patients were included if receiving controlled mandatory ventilation and arterial line monitoring. Anaesthetists determined the FiO₂ and the oxygenation saturation (SpO₂) targets. An arterial blood gas (ABG) was obtained 15-20 minutes after induction of anaesthesia, immediately before the emergence phase of anaesthesia and 15 minutes after arrival in the post-anaesthesia care unit (PACU). We defined hyperoxaemia as a PaO₂ of >150 mmHg and included a further threshold of PaO₂ >200 mmHg. We studied 373 patients. The median (interquartile range (IQR)) lowest intraoperative FiO₂ and SpO₂ values were 0.45 (IQR 0.4-0.5) and 97% (IQR 96-98%), respectively, with a median PaO₂ on the first and second ABG of 237 mmHg (IQR 171-291 mmHg) and 189 mmHg (IQR 145-239 mmHg), respectively. In the PACU, the median lowest oxygen flow rate was 6 L/min (IQR 3-6 L/min), and the PaO₂ was 158 mmHg (IQR 120-192 mmHg). Hyperoxaemia occurred in 82%, 73% and 54% of participants on the first and second intraoperative and postoperative ABGs respectively. A PaO₂ of >200 mmHg occurred in 64%, 41% and 21% of these blood gases, respectively. In an Australian tertiary hospital, a liberal approach to FiO₂ and PaO₂ was most common and resulted in a high incidence of perioperative hyperoxaemia.

Guideline for the management of COVID-19 patients during hospital admission in a non-intensive care setting

INTRODUCTION

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has presented health-care systems worldwide with novel challenges and experiences and evidence is emerging during the pandemic. Patients requiring hospitalization frequently suffer from respiratory failure of different severities.

AIM

The aim of this guideline is the treatment of patients with SARS CoV-2 (COVID-19) in hospital; in particular, it addresses the treatment of respiratory failure treated in general Internal Medical- and Pulmonary Medical wards.

RESULTS

Elderly patients and patients with chronic disease are particularly vulnerable to COVID-19. Target oxygen saturation should be between 92% and 96% in patients without chronic lung diseases. Treatment with >5 L oxygen/min should be in close collaboration with intensive care colleagues and >15 l/min preferably in intensive care units. High-flow nasal canula (HFNC) and long-term Continuous Positive Airway Pressure (CPAP) are recommended for patients not responding to conventional oxygen therapy. Non-invasive ventilation (NIV) is only recommended for selected patients, such as those with a ceiling of treatment or patients presenting with hypercapnic failure. With the use of humidification protective equipment as FFP2-3 masks should be used. Nebulized medication should be avoided, and spacers should be used instead.

CONCLUSION

Respiratory failure is frequently the cause of hospitalization in patients with COVID-19 and should be monitored closely.

Respiratory support in patients with COVID-19 (outside intensive care unit). A position paper of the Respiratory Support and Chronic Care Group of the French Society of Respiratory Diseases

With first cases noted towards the end of 2019 in China, COVID-19 infection was rapidly become a devastating pandemic. Even if most patients present with a mild to moderate form of the disease, the estimated prevalence of COVID-19-related severe acute respiratory failure (ARF) is 15–20% and 2–12% needed intubation and mechanical ventilation. In addition to mechanical ventilation some other techniques of respiratory support could be used in some forms of COVID-19 related ARF. This position paper of the Respiratory Support and Chronic Care Group of the French Society of Respiratory Diseases is intended to help respiratory clinicians involved in care of COVID-19 pandemic in the rational use of non-invasive techniques such as oxygen therapy, CPAP, non-invasive ventilation and high flow oxygen therapy in managing patients outside intensive care unit (ICU). The aims are: (1) to focus both on the place of each technique and in describing practical tips (types of devices and circuit assemblies) aimed to limit the risk of caregivers when using those techniques at high risk spreading of viral particles; (2) to propose a step-by-step strategy to manage ARF outside ICU.