Ben Creagh-Brown

BTS/ICS guideline for the ventilatory management of acute hypercapnic respiratory failure in adults

### Principles of mechanical ventilation #### Modes of mechanical ventilation Recommendation 1. Pressure-targeted ventilators are the devices of choice for acute NIV (Grade B). Good practice points #### Choice of interface for NIV Recommendation 2. A full face mask (FFM) should usually be the first type of interface used (Grade D). Good practice points #### Indications for and contra-indications to NIV in AHRF Recommendation 3. The presence of adverse features increase the risk of NIV failure and should prompt consideration of placement in high dependency unit (HDU)/intensive care unit (ICU) (Grade C). Good practice points #### Monitoring during NIV Good practice points #### Supplemental oxygen therapy with NIV Recommendations 4. Oxygen enrichment should be adjusted to achieve SaO2 88–92% in all causes of acute hypercapnic respiratory failure (AHRF) treated by NIV (Grade A). 5. Oxygen should be entrained as close to the patient as possible (Grade C). Good practice points

British Thoracic Society/Intensive Care Society Guideline for the ventilatory management of acute hypercapnic respiratory failure in adults

The British Thoracic Society (BTS) published the guideline ‘The use of non-invasive ventilation in acute respiratory failure’ in 2002.1 This was in response to trials that had demonstrated that non-invasive ventilation (NIV) was an alternative to invasive mechanical ventilation (IMV) in life-threatening respiratory acidosis due to acute exacerbations of chronic obstructive pulmonary disease (AECOPD). It drew attention to evidence that, when NIV was used in the less severely unwell patient, it also limited progression to more severe respiratory failure.2 The trial also demonstrated the feasibility, of delivering NIV on general medical or admission wards that had enhanced support and when staff were provided with ongoing training. In subsequent years, NIV has been shown to deliver better rather than equivalent outcomes to invasive ventilation in AECOPD and better evidence has accumulated for the use of NIV in non-COPD disease in the intervening years. Repeated national audits have, however, raised concerns that expected patient benefit is not being delivered and have pointed to a number of process deficiencies.3–5 There is also the risk, in the absence of justifying trial evidence, that the preferred use of NIV in AECOPD might be extended to all hypercapnic patients, irrespective of circumstance or underlying disease process. That this is a real risk might be inferred from the BTS audits where the indication for NIV was not COPD in over 30% of cases.3 ,4 NIV development in the UK has been largely outside the organisational ‘umbrella’ of critical care. This may have adversely affected resource allocation and contributed to a lack of integration in NIV and IMV patient pathways. Other unintended consequences might be a restriction on access to invasive ventilation and delay in the development of extended applications of NIV, such as accelerating extubation and its use in the management of …

Psychological rumination and recovery from work in intensive care professionals: associations with stress, burnout, depression and health

BackgroundThe work demands of critical care can be a major cause of stress in intensive care unit (ICU) professionals and lead to poor health outcomes. In the process of recovery from work, psychological rumination is considered to be an important mediating variable in the relationship between work demands and health outcomes. This study aimed to extend our knowledge of the process by which ICU stressors and differing rumination styles are associated with burnout, depression and risk of psychiatric morbidity among ICU professionals.MethodsNinety-six healthcare professionals (58 doctors and 38 nurses) who work in ICUs in the UK completed a questionnaire on ICU-related stressors, burnout, work-related rumination, depression and risk of psychiatric morbidity.ResultsSignificant associations between ICU stressors, affective rumination, burnout, depression and risk of psychiatric morbidity were found. Longer working hours were also related to increased ICU stressors. Affective rumination (but not problem-solving pondering or distraction detachment) mediated the relationship between ICU stressors, burnout, depression and risk of psychiatric morbidity, such that increased ICU stressors, and greater affective rumination, were associated with greater burnout, depression and risk of psychiatric morbidity. No moderating effects were observed.ConclusionsLonger working hours were associated with increased ICU stressors, and increased ICU stressors conferred greater burnout, depression and risk of psychiatric morbidity via increased affective rumination. The importance of screening healthcare practitioners within intensive care for depression, burnout and psychiatric morbidity has been highlighted. Future research should evaluate psychological interventions which target rumination style and could be made available to those at highest risk. The efficacy and cost effectiveness of delivering these interventions should also be considered.

Prospective observational cohort study of patients with weaning failure admitted to a specialist weaning, rehabilitation and home mechanical ventilation centre

Objectives According to National Health Service England (NHSE) specialist respiratory commissioning specification for complex home ventilation, patients with weaning failure should be referred to a specialist centre. However, there are limited data reporting the clinical outcomes from such centres. Setting Prospective observational cohort study of patients admitted to a UK specialist weaning, rehabilitation and home mechanical ventilation centre between February 2005 and July 2013. Participants 262 patients admitted with a median age of 64.2 years (IQR 52.6–73.2 years). 59.9% were male. Results 39.7% of patients had neuromuscular and/or chest wall disease, 21% were postsurgical, 19.5% had chronic obstructive pulmonary disease (COPD), 5.3% had obesity-related respiratory failure and 14.5% had other diagnoses. 64.1% of patients were successfully weaned, with 38.2% weaned fully from ventilation, 24% weaned to nocturnal non-invasive ventilation (NIV), 1.9% weaned to nocturnal NIV with intermittent NIV during the daytime. 21.4% of patients were discharged on long-term tracheostomy ventilation. The obesity-related respiratory failure group were most likely to wean (relative risk (RR) for weaning success=1.48, 95% CI 1.35 to 1.77; p<0.001), but otherwise weaning success rates did not significantly vary by diagnostic group. The median time-to-wean was 19 days (IQR 9–33) and the median duration of stay was 31 days (IQR 16–50), with no difference observed between the groups. Weaning centre mortality was 14.5%, highest in the COPD group (RR=2.15, 95% CI 1.19 to 3.91, p=0.012) and lowest in the neuromuscular and/or chest wall disease group (RR=0.34, 95% CI 0.16 to 0.75, p=0.007). Of all patients discharged alive, survival was 71.7% at 6 months and 61.8% at 12 months postdischarge. Conclusions Following NHSE guidance, patients with weaning delay and failure should be considered for transfer to a specialist centre where available, which can demonstrate favourable short-term and long-term clinical outcomes.

Benefits of β blockers in chronic obstructive pulmonary disease and heart failure.

Williams and Oakeshott caution against the use of the β blocker bisoprolol for chronic heart failure in patients with severe asthma or chronic obstructive …

British Thoracic Society Quality Standards for acute non-invasive ventilation in adults

Introduction The purpose of the quality standards document is to provide healthcare professionals, commissioners, service providers and patients with a guide to standards of care that should be met for the provision of acute non-invasive ventilation in adults together with measurable markers of good practice. Methods Development of British Thoracic Society (BTS) Quality Standards follows the BTS process of quality standard production based on the National Institute for Health and Care Excellence process manual for the development of quality standards. Results 6 quality statements have been developed, each describing a standard of care for the provision of acute non-invasive ventilation in the UK, together with measurable markers of good practice. Conclusion BTS Quality Standards for acute non-invasive ventilation in adults form a key part of the range of supporting materials that the Society produces to assist in the dissemination and implementation of guideline’s recommendations.

Type 2 diabetes: A protective factor for COPD?

BACKGROUND Chronic obstructive pulmonary disease (COPD) and type 2 diabetes (T2DM) are common comorbidities. COPD is a known risk factor for incident T2DM, however few studies have examined the relationship in reverse. The primary aim of this study was to compare the incidence of COPD in people with and without T2DM. MATERIALS AND METHODS We conducted a retrospective case-control study using a long-established English general practice network database (n=894,646). We matched 29,217 cases of T2DM with controls, adjusting for age, gender, smoking status, BMI and social deprivation, to achieve 1:1 propensity matching and compared the rate of incident COPD over eight years of follow-up. We performed a secondary analysis to investigate the effect of insulin, metformin and sulphonylureas on COPD incidence. RESULTS People with T2DM had a reduced risk of COPD compared to matched controls over the follow-up period (HR 0.89, 95%CI 0.79-0.93). 48.5% of those with T2DM were ex-smokers compared with 27.3% of those without T2DM. Active smoking rates were 20.4% and 23.7% respectively. Insulin, metformin and sulphonylureas were not associated with incident COPD. CONCLUSIONS People with T2DM are less likely to be diagnosed with COPD than matched controls. This may be due to positive lifestyle changes, such as smoking cessation in those with T2DM.

What are the optimum components in a care bundle aimed at reducing post-operative pulmonary complications in high-risk patients?

BackgroundPost-operative pulmonary complications (POPC) are common, predictable and associated with increased morbidity and mortality, independent of pre-operative risk. Interventions to reduce the incidence of POPC have been studied individually, but the use of a care bundle has not been widely investigated. The purpose of our work was to use Delphi consensus methodology and an independently chosen expert panel to formulate a care bundle for patients identified as being at high of POPC, as preparation towards an evaluation of its effectiveness at reducing POPC.MethodsWe performed a survey of members of the ESICM POIC section to inform a Delphi consensus and to share their opinions on a care bundle to reduce POPC, the POPC-CB. We formed a team of 36 experts to participate in and complete an email-based Delphi consensus over three rounds, leading to the formulation of the POPC-CB.ResultsThe survey had 362 respondents and informed the design of the Delphi consensus. The Delphi consensus resulted in a proposed POPC-CB that incorporates components before surgery-supervised exercise programmes and inspiratory muscle training, during surgery, low tidal volume ventilation with individualised PEEP (positive end-expiratory pressure), use of routine monitoring to avoid hyperoxia and efforts made to limit neuromuscular blockade, and post-operatively, deep breathing exercises and elevation of the head of the bed.ConclusionA care bundle has been suggested for evaluation in surgical patients at high risk of POPC. Evaluation of feasibility of both implementation and effectiveness is now indicated.

Type 2 Diabetes And Asthma: Systematic Review

BACKGROUND AND OBJECTIVE Obesity is an important contributor to the risk of both asthma and Type 2 Diabetes (T2DM). However, it has been suggested that T2DM and asthma are also independently associated. The aim of this systematic review was to synthesize the evidence for an independent relationship between T2DM and asthma. METHODS MEDLINE and EMBASE were searched for studies reporting the relationship between asthma and T2DM in adults. Given a potential bidirectional relationship, articles relating to T2DM as a risk factor for asthma, and asthma as a risk factor for T2DM were examined separately. RESULTS Eight studies were identified for inclusion in the review (n=2,934,399 participants). Four studies examined incident diabetes in those with asthma. The pooled (random effects model) adjusted hazard ratio for incident T2DM in asthma was 1.37 (95%CI 1.12-1.69; p <0.001) after controlling for BMI. Four studies reported prevalence or incidence rates of asthma in people with T2DM; higher rates of asthma in those with T2DM were reported in all four studies. Meta-analysis of results was not possible due to methodological heterogeneity. The quality of included studies was good, but due to small numbers, publication bias cannot be excluded. CONCLUSION The published literature suggests a bidirectional independent relationship between T2DM and asthma, although we cannot exclude publication bias.

Definitions and pathophysiology of vasoplegic shock

Vasoplegia is the syndrome of pathological low systemic vascular resistance, the dominant clinical feature of which is reduced blood pressure in the presence of a normal or raised cardiac output. The vasoplegic syndrome is encountered in many clinical scenarios, including septic shock, post-cardiac bypass and after surgery, burns and trauma, but despite this, uniform clinical definitions are lacking, which renders translational research in this area challenging. We discuss the role of vasoplegia in these contexts and the criteria that are used to describe it are discussed. Intrinsic processes which may drive vasoplegia, such as nitric oxide, prostanoids, endothelin-1, hydrogen sulphide and reactive oxygen species production, are reviewed and potential for therapeutic intervention explored. Extrinsic drivers, including those mediated by glucocorticoid, catecholamine and vasopressin responsiveness of the blood vessels, are also discussed. The optimum balance between maintaining adequate systemic vascular resistance against the potentially deleterious effects of treatment with catecholamines is as yet unclear, but development of novel vasoactive agents may facilitate greater understanding of the role of the differing pathways in the development of vasoplegia. In turn, this may provide insights into the best way to care for patients with this common, multifactorial condition.