Timing and burden of persistent critical illnessin UK intensive care units: An observational cohort study.

Background: Persistent critical illness is a recognisable clinical syndrome defined conceptually as when the patient's reason for being in the intensive care unit (ICU) is more related to their ongoing critical illness than their original reason for admission. Our objectives were: (1) to assess the day in ICU on which chronic factors (e.g., age, gender and comorbidities) were more predictive of survival than acute factors (e.g. admission diagnosis, physiological derangements) measured on the day of admission; (2) to assess the consistency of this finding across major patient subgroups and over time and (3) to compare case mix characteristics and outcomes for patients determined to develop persistent critical illness (based on ICU length of stay) with other patients. Methods: Observational cohort study using a high-quality clinical database from the national clinical audit of adult critical care. 217 adult ICUs in England, Wales and Northern Ireland. 835,946 adult patients admitted to participating ICUs between 1 April 2009 and 31 March 2016. The main outcome measure was mortality at discharge from acute hospital. Results: We fitted two statistical models ('chronic' and 'acute') and updated these based upon patients with an ICU length of stay of at least 1, 2, etc., up to 28 days. The discrimination of the chronic model first exceeded that of the acute model on day 11. Patients with longer stays (>10 days) comprised 9% of admissions but used 45% of ICU bed-days. After a mean ICU length of stay of 22 days and a subsequent 28 days in hospital, 30% died. Conclusions: Persistent critical illness is commonly encountered in clinical practice and is associated with increased healthcare utilisation and adverse outcomes. Improvements in our understanding of the longer term outcomes and in the development of tools to aid prognostication are urgently required - for humane as well as health economic reasons.

Remote Ischaemic Preconditioning in Intra-Abdominal Cancer Surgery (RIPCa): A Pilot Randomised Controlled Trial.

There is limited evidence on the effect of remote ischaemic preconditioning (RIPC) following non-cardiac surgery. The aim of this study was to investigate the effect of RIPC on morbidity following intra-abdominal cancer surgery. We conducted a double blinded pilot randomised controlled trial that included 47 patients undergoing surgery for gynaecological, pancreatic and colorectal malignancies. The patients were randomized into an intervention (RIPC) or control group. RIPC was provided by intermittent inflations of an upper limb tourniquet. The primary outcome was feasibility of the study, and the main secondary outcome was postoperative morbidity including perioperative troponin change and the urinary biomarkers tissue inhibitor of metalloproteinases-2 and insulin-like growth factor-binding protein 7 (TIMP-2*IGFBP-7). The recruitment target was reached, and the protocol procedures were followed. The intervention group developed fewer surgical complications at 30 days (4.5% vs. 33%), 90 days (9.5% vs. 35%) and 6 months (11% vs. 41%) (adjusted p 0.033, 0.044 and 0.044, respectively). RIPC was a significant independent variable for lower overall postoperative morbidity survey (POMS) score, OR 0.79 (95% CI 0.63 to 0.99) and fewer complications at 6 months including pulmonary OR 0.2 (95% CI 0.03 to 0.92), surgical OR 0.12 (95% CI 0.007 to 0.89) and overall complications, OR 0.18 (95% CI 0.03 to 0.74). There was no difference in perioperative troponin change or TIMP2*IGFBP-7. Our pilot study suggests that RIPC may improve outcomes following intra-abdominal cancer surgery and that a larger trial would be feasible.

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.

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

BACKGROUND: Post-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. METHODS: We 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. RESULTS: The 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. CONCLUSION: A 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.

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.

Relationship Between Peak Lactate and Patient Outcome Following High-Risk Gastrointestinal Surgery: Influence of the Nature of Their Surgery: Elective Versus Emergency.

OBJECTIVES: The association between hyperlactatemia and adverse outcome in patients admitted to ICUs following gastrointestinal surgery has not been reported. To explore the hypothesis that in a large cohort of gastrointestinal surgical patients, the peak serum lactate (in the first 24 hr) observed in patients admitted to ICU following surgery is associated with unadjusted and severity-adjusted acute hospital mortality and that the strength of association is greater in patients admitted following "emergency" surgery than in patients admitted following "elective" surgery. DESIGN: A retrospective cohort study of all patients who had gastrointestinal surgery and were admitted directly to the ICU between 2008 and 2012. SETTING: Two hundred forty-nine hospitals in the United Kingdom. PATIENTS: One hundred twenty-one thousand nine hundred ninety patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Peak blood lactate in the first 24 hours of admission to critical care, acute hospital mortality, length of stay, and other variables routinely collected within the U.K. Intensive Care National Audit and Research Centre Case Mix Programme database. Elevated blood lactate was associated with increased risk of death and prolonged duration of stay, and the relationship was maintained once adjusted for confounding variables. The positive association between mortality and levels of blood lactate continued down into the "normal range," without evidence of a plateau. There was no difference in the extent to which hyperlactatemia was related to mortality between patients admitted following elective and emergency surgery. CONCLUSIONS: These findings have implications for our understanding of the role of lactate in critically ill patients.

The promise of next generation colloids.

The aim of perioperative haemodilution is to reduce loss of red blood cells during elective surgery. The oncotic and molecular characteristics of the various plasma substitutes employed determine how effectively normovolaemia is maintained, and their non-oncotic effects include alterations in microvascular perfusion. In the previous issue of Critical Care, Martini and colleagues assessed the effects of haemodilution with either polyethylene glycol (PEG)ylated albumin or a commercially available hydroxyethyl starch-based colloid in a hamster haemorrhage model. PEGylated albumin was superior to hydroxyethyl starch, as reflected by survival, haemodynamic parameters and assessment of the microcirculation using intravital microscopy.

An under-recognized complication of treatment of acute severe asthma.

A 39-year-old man presented to the emergency department (ED) in severe respiratory distress. He had a prior diagnosis of brittle asthma and had been admitted on several occasions but never previously ventilated. Therapy given in the first 3 hours of arrival included nebulized salbutamol (5 mg, x5), ipratropium bromide (0.5 mg), intravenous hydrocortisone (200 mg), and magnesium sulfate (2 g). His arterial blood gases continued to deteriorate. He was then given an intravenous bolus of salbutamol (250 microg) and heliox via facemask. His worsening status necessitated invasive ventilation. His hypercapnia and resultant respiratory acidosis improved rapidly, but there was a concurrent accumulation of lactic acid resulting in acidemia. This patient had lactic acidosis as a direct effect of administration of salbutamol. The development of hazardous salbutamol-induced toxicity in acute severe asthma is discussed.