The association between ICU admission and emergency hospital readmission following emergency general surgery

Background

The relationship between postoperative intensive care (ICU) admission following emergency general surgery (EGS) and emergency hospital readmission has not been widely investigated.

Methods

Retrospective analysis of registry data for patients undergoing EGS in Scotland, 2005-2007. Exposure of interest was ICU admission status (direct from theatre; indirect after initial care on ward; no ICU admission). The primary outcome was emergency hospital readmission within 30 days of discharge.

Results

Thirty-seven thousand one hundred seventy-three patients were included in the analysis. Overall emergency readmission rate was 8% (n = 2983): 2756 (7.8%) in patients without postoperative ICU admission; 155 (12.1%) with direct ICU admission and 65 (14.7%) with indirect ICU admission. Indirect ICU admission was associated with increased hospital readmission rates (HR 1.24 [1.03, 1.49]; p = 0.024) compared with direct ICU admission. ICU admission was associated with increased three-year readmission rates (p = 0.006) and costs (p < 0.001) compared with initial ward care.

Conclusion

Indirect ICU admission is associated with increased emergency hospital readmission and healthcare costs for patients undergoing EGS.

Intensive care utilization and outcomes after high-risk surgery in Scotland: a population-based cohort study

BACKGROUND

The optimal perioperative use of intensive care unit (ICU) resources is not yet defined. We sought to determine the effect of ICU admission on perioperative (30 day) and long-term mortality.

METHODS

This was an observational study of all surgical patients in Scotland during 2005-7 followed up until 2012. Patient, operative, and care process factors were extracted. The primary outcome was perioperative mortality; secondary outcomes were 1 and 4 yr mortality. Multivariable regression was used to construct a risk prediction model to allow standard-risk and high-risk groups to be defined based on deciles of predicted perioperative mortality risk, and to determine the effect of ICU admission (direct from theatre; indirect after initial care on ward; no ICU admission) on outcome adjusted for confounders.

RESULTS

There were 572 598 patients included. The risk model performed well (c-index 0.92). Perioperative mortality occurred in 1125 (0.2%) in the standard-risk group (n=510 979) and in 3636 (6.4%) in the high-risk group (n=56 785). Patients with no ICU admission within 7 days of surgery had the lowest perioperative mortality (whole cohort 0.7%; high-risk cohort 5.3%). Indirect ICU admission was associated with a higher risk of perioperative mortality when compared with direct admission for the whole cohort (20.9 vs 12.1%; adjusted odds ratio 2.39, 95% confidence interval 2.01-2.84; P<0.01) and for high-risk patients (26.2 vs 17.8%; adjusted odds ratio 1.64, 95% confidence interval 1.37-1.96; P<0.01). Compared with direct ICU admission, indirectly admitted patients had higher severity of illness on admission, required more organ support, and had an increased duration of ICU stay.

CONCLUSIONS

Indirect ICU admission was associated with increased mortality and increased requirement for organ support.

TRIAL REGISTRATION

UKCRN registry no. 15761.

Effect of Protocolized Weaning With Early Extubation to Noninvasive Ventilation vs Invasive Weaning on Time to Liberation From Mechanical Ventilation Among Patients With Respiratory Failure: The Breathe Randomized Clinical Trial

IMPORTANCE

In adults in whom weaning from invasive mechanical ventilation is difficult, noninvasive ventilation may facilitate early liberation, but there is uncertainty about its effectiveness in a general intensive care patient population.

OBJECTIVE

To investigate among patients with difficulty weaning the effects of protocolized weaning with early extubation to noninvasive ventilation on time to liberation from ventilation compared with protocolized invasive weaning.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, allocation-concealed, open-label, multicenter clinical trial enrolling patients between March 2013 and October 2016 from 41 intensive care units in the UK National Health Service. Follow-up continued until April 2017. Adults who received invasive mechanical ventilation for more than 48 hours and in whom a spontaneous breathing trial failed were enrolled.

INTERVENTIONS

Patients were randomized to receive either protocolized weaning via early extubation to noninvasive ventilation (n = 182) or protocolized standard weaning (continued invasive ventilation until successful spontaneous breathing trial, followed by extubation) (n = 182).

MAIN OUTCOMES AND MEASURES

Primary outcome was time from randomization to successful liberation from all forms of mechanical ventilation among survivors, measured in days, with the minimal clinically important difference defined as 1 day. Secondary outcomes were duration of invasive and total ventilation (days), reintubation or tracheostomy rates, and survival.

RESULTS

Among 364 randomized patients (mean age, 63.1 [SD, 14.8] years; 50.5% male), 319 were evaluable for the primary effectiveness outcome (41 died before liberation, 2 withdrew, and 2 were discharged with ongoing ventilation). The median time to liberation was 4.3 days in the noninvasive group vs 4.5 days in the invasive group (adjusted hazard ratio, 1.1; 95% CI, 0.89-1.40). Competing risk analysis accounting for deaths had a similar result (adjusted hazard ratio, 1.1; 95% CI, 0.86-1.34). The noninvasive group received less invasive ventilation (median, 1 day vs 4 days; incidence rate ratio, 0.6; 95% CI, 0.47-0.87) and fewer total ventilator days (median, 3 days vs 4 days; incidence rate ratio, 0.8; 95% CI, 0.62-1.0). There was no significant difference in reintubation, tracheostomy rates, or survival. Adverse events occurred in 45 patients (24.7%) in the noninvasive group compared with 47 (25.8%) in the invasive group.

CONCLUSIONS AND RELEVANCE

Among patients requiring mechanical ventilation in whom a spontaneous breathing trial had failed, early extubation to noninvasive ventilation did not shorten time to liberation from any ventilation.

TRIAL REGISTRATION

ISRCTN Identifier: ISRCTN15635197.

Unrecognised myocardial infarction and its relationship to outcome in critically ill patients with cardiovascular disease

PURPOSE

To establish the incidence of myocardial infarction (MI) in ICU patients with co-existing cardiovascular disease (CVD), and explore its association with long-term survival.

METHODS

In a multi-centre prospective cohort study in 11 UK ICUs, we enrolled 273 critically ill patients with co-existing CVD. We measured troponin I (cTnI) with a high sensitivity assay for 10 days; ECGs were carried out daily for 5 days and analysed by blinded cardiologists for dynamic changes. Data were combined to diagnose myocardial 'infarction', 'injury' or 'no injury' according to the third universal definition of MI. Patients were followed-up for 6 months. Regression and mediation analyses were used to explore relationships between acute physiological derangements, MI, and mortality.

RESULTS

cTnI was detected in all patients, with a rise/fall pattern consistent with an acute hit. In 73% of patients, this peaked on days 1-3 [median 114 ng/l (first, third quartiles: 27, 393)]. Serial ECGs indicated 24.2% (n = 66) of patients experienced MI, but > 95% were unrecognized by clinical teams. Type 2 MI was the most likely aetiology in all cases. A further 46.1% (n = 126) experienced injury (no ECG changes). Injury and MI were both associated with 6-month mortality (reference: no injury): OR injury 2.28 (95% CI 1.06-4.92, p = 0.035), OR MI 2.70 (95% CI 1.11-6.55, p = 0.028). Mediation analysis suggested MI partially mediated the relationship between acute physiological derangement and 6-month mortality (p = 0.002), suggesting a possible causal association.

CONCLUSIONS

Undiagnosed MI occurs in around a quarter of critically ill patients with co-existing CVD and is associated with lower long-term survival.

Early PREdiction of sepsis using leukocyte surface biomarkers: the ExPRES-sepsis cohort study

PURPOSE

Reliable biomarkers for predicting subsequent sepsis among patients with suspected acute infection are lacking. In patients presenting to emergency departments (EDs) with suspected acute infection, we aimed to evaluate the reliability and discriminant ability of 47 leukocyte biomarkers as predictors of sepsis (Sequential Organ Failure Assessment score ≥ 2 at 24 h and/or 72 h following ED presentation).

METHODS

In a multi-centre cohort study in four EDs and intensive care units (ICUs), we standardised flow-cytometric leukocyte biomarker measurement and compared patients with suspected acute infection (cohort-1) with two comparator cohorts: ICU patients with established sepsis (cohort-2), and ED patients without infection or systemic inflammation but requiring hospitalization (cohort-3).

RESULTS

Between January 2014 and February 2016, we recruited 272, 59 and 75 patients to cohorts 1, 2, and 3, respectively. Of 47 leukocyte biomarkers, 14 were non-reliable, and 17 did not discriminate between the three cohorts. Discriminant analyses for predicting sepsis within cohort-1 were undertaken for eight neutrophil (cluster of differentiation antigens (CD) CD15; CD24; CD35; CD64; CD312; CD11b; CD274; CD279), seven monocyte (CD35; CD64; CD312; CD11b; HLA-DR; CD274; CD279) and a CD8 T-lymphocyte biomarker (CD279). Individually, only higher neutrophil CD279 [OR 1.78 (95% CI 1.23-2.57); P = 0.002], higher monocyte CD279 [1.32 (1.03-1.70); P = 0.03], and lower monocyte HLA-DR [0.73 (0.55-0.97); P = 0.03] expression were associated with subsequent sepsis. With logistic regression the optimum biomarker combination was increased neutrophil CD24 and neutrophil CD279, and reduced monocyte HLA-DR expression, but no combination had clinically relevant predictive validity.

CONCLUSIONS

From a large panel of leukocyte biomarkers, immunosuppression biomarkers were associated with subsequent sepsis in ED patients with suspected acute infection.

CLINICAL TRIAL REGISTRATION

NCT02188992.

The Age of BLood Evaluation (ABLE) randomised controlled trial: description of the UK-funded arm of the international trial, the UK cost-utility analysis and secondary analyses exploring factors associated with health-related quality of life and health-care costs during the 12-month follow-up

BACKGROUND

At present, red blood cells (RBCs) are stored for up to 42 days prior to transfusion. The relative effectiveness and safety of different RBC storage times prior to transfusion is uncertain.

OBJECTIVE

To assess the clinical effectiveness and cost-effectiveness of transfusing fresher RBCs (stored for ≤ 7 days) compared with current standard-aged RBCs in critically ill patients requiring blood transfusions.

DESIGN

The international Age of BLood Evaluation (ABLE) trial was a multicentre, randomised, blinded trial undertaken in Canada, the UK, the Netherlands and France. The UK trial was funded to contribute patients to the international trial and undertake a UK-specific health economic evaluation.

SETTING

Twenty intensive care units (ICUs) in the UK, as part of 64 international centres.

PARTICIPANTS

Critically ill patients aged ≥ 18 years (≥ 16 years in Scotland) expected to require mechanical ventilation for ≥ 48 hours and requiring a first RBC transfusion during the first 7 days in the ICU.

INTERVENTIONS

All decisions to transfuse RBCs were made by clinicians. One patient group received exclusively fresh RBCs stored for ≤ 7 days whenever transfusion was required from randomisation until hospital discharge. The other group received standard-issue RBCs throughout their hospital stay.

MAIN OUTCOME MEASURES

The primary outcome was 90-day mortality. Secondary outcomes included development of organ dysfunction, new thrombosis, infections and transfusion reactions. The primary economic evaluation was a cost-utility analysis.

RESULTS

The international trial took place between March 2009 and October 2014 (UK recruitment took place between January 2012 and October 2014). In total, 1211 patients were assigned to receive fresh blood and 1219 patients to receive standard-aged blood. RBCs were stored for a mean of 6.1 days [standard deviation (SD) ± 4.9 days] in the group allocated to receive fresh blood and 22.0 days (SD ± 8.4 days) in the group allocated to receive standard-aged blood. Patients received a mean of 4.3 RBC units (SD ± 5.2 RBC units) and 4.3 RBC units (SD ± 5.5 RBC units) in the groups receiving fresh blood and standard-aged blood, respectively. At 90 days, 37.0% of patients in the group allocated to receive fresh blood and 35.3% of patients in the group allocated to receive standard-aged blood had died {absolute risk difference 1.7% [95% confidence interval (CI) -2.1% to 5.5%]}. There were no between-group differences in any secondary outcomes. The UK cohort comprised 359 patients randomised and followed up for 12 months for the cost-utility analysis. UK patients had similar characteristics and outcomes to the international cohort. Mean total costs per patient were £32,346 (95% CI £29,306 to £35,385) in the group allocated to receive fresh blood and £33,353 (95% CI £29,729 to £36,978) in the group allocated to receive standard-aged blood. Approximately 85% of the total costs were incurred during the index hospital admission. There were no significant cost differences between the two groups [mean incremental costs for those receiving fresh vs. standard-aged blood: -£231 (95% CI -£4876 to £4415)], nor were there significant differences in outcomes (mean difference in quality-adjusted life-years -0.010, 95% CI -0.078 to 0.057).

LIMITATIONS

Adverse effects from the exclusive use of older RBCs compared with standard or fresh RBCs cannot be excluded.

CONCLUSIONS

The use of RBCs aged ≤ 7 days confers no clinical or economic benefit in critically ill patients compared with standard-aged RBCs.

FUTURE WORK

Future studies should address the safety of RBCs near the end of the current permitted storage age.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN44878718.

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. 21, No. 62. See the NIHR Journals Library website for further project information. The international ABLE trial was also supported by peer-reviewed grants from the Canadian Institutes of Health Research (177453), Fonds de Recherche du Québec - Santé (24460), the French Ministry of Health Programme Hospitalier de Recherche Clinique (12.07, 2011) and by funding from Établissement Français du Sang and Sanquin Blood Supply.

Cell-surface signatures of immune dysfunction risk-stratify critically ill patients: INFECT study

PURPOSE

Cellular immune dysfunctions, which are common in intensive care patients, predict a number of significant complications. In order to effectively target treatments, clinically applicable measures need to be developed to detect dysfunction. The objective was to confirm the ability of cellular markers associated with immune dysfunction to stratify risk of secondary infection in critically ill patients.

METHODS

Multi-centre, prospective observational cohort study of critically ill patients in four UK intensive care units. Serial blood samples were taken, and three cell surface markers associated with immune cell dysfunction [neutrophil CD88, monocyte human leucocyte antigen-DR (HLA-DR) and percentage of regulatory T cells (Tregs)] were assayed on-site using standardized flow cytometric measures. Patients were followed up for the development of secondary infections.

RESULTS

A total of 148 patients were recruited, with data available from 138. Reduced neutrophil CD88, reduced monocyte HLA-DR and elevated proportions of Tregs were all associated with subsequent development of infection with odds ratios (95% CI) of 2.18 (1.00-4.74), 3.44 (1.58-7.47) and 2.41 (1.14-5.11), respectively. Burden of immune dysfunction predicted a progressive increase in risk of infection, from 14% for patients with no dysfunction to 59% for patients with dysfunction of all three markers. The tests failed to risk stratify patients shortly after ICU admission but were effective between days 3 and 9.

CONCLUSIONS

This study confirms our previous findings that three cell surface markers can predict risk of subsequent secondary infection, demonstrates the feasibility of standardized multisite flow cytometry and presents a tool which can be used to target future immunomodulatory therapies.

TRIAL REGISTRATION

The study was registered with clinicaltrials.gov (NCT02186522).

Evaluation of Staphylococcus aureus eradication therapy in orthopaedic surgery

PURPOSE

Despite WHO recommendations, there is currently no national screening and eradication policy for the detection of methicillin-sensitive Staphylococcus aureus (MSSA) in the UK prior to elective orthopaedic surgery. This study aimed to evaluate the effectiveness of current standard methicillin-resistant S. aureus (MRSA) eradication therapies in the context of S. aureus (both MRSA and MSSA) decolonization in an elective orthopaedic population.

METHODOLOGY

A total of 100 patients awaiting joint replacement surgery who were positive for S. aureus on PCR nasal screening underwent the current standard MRSA pre-operative decolonization regimen for 5 days. Prior to commencement of the eradication therapy, swabs of the anterior nares, throat and perineum were taken for culture. Further culture swabs were taken at 48-96 h following treatment, at hospital admission for surgery and at hospital discharge. Following the completion of treatment, patients were asked to provide feedback on their experience using Likert rating scales. The primary outcome of this study was S. aureus clearance 48-96 h following eradication treatment.Results/Key Findings. Clearance of S. aureus 48-96 h following treatment was 94 % anterior nares, 66 % throat and 88 % groin. Mean completion with nasal mupirocin was 98 %. There was no statistically significant recolonization effect between the end of the eradication treatment period and the day of surgery (P>0.05) at a median time of 10 days.

CONCLUSION

Current MRSA decolonisation regimens are well tolerated and effective for MSSA decolonization for the anterior nares and groin. The decolonization effect is preserved for at least 10 days following treatment.

Predicting risk of unplanned hospital readmission in survivors of critical illness: a population-level cohort study

BACKGROUND

Intensive care unit (ICU) survivors experience high levels of morbidity after hospital discharge and are at high risk of unplanned hospital readmission. Identifying those at highest risk before hospital discharge may allow targeting of novel risk reduction strategies. We aimed to identify risk factors for unplanned 90-day readmission, develop a risk prediction model and assess its performance to screen for ICU survivors at highest readmission risk.

METHODS

Population cohort study linking registry data for patients discharged from general ICUs in Scotland (2005-2013). Independent risk factors for 90-day readmission and discriminant ability (c-index) of groups of variables were identified using multivariable logistic regression. Derivation and validation risk prediction models were constructed using a time-based split.

RESULTS

Of 55 975 ICU survivors, 24.1% (95%CI 23.7% to 24.4%) had unplanned 90-day readmission. Pre-existing health factors were fair discriminators of readmission (c-index 0.63, 95% CI 0.63 to 0.64) but better than acute illness factors (0.60) or demographics (0.54). In a subgroup of those with no comorbidity, acute illness factors (0.62) were better discriminators than pre-existing health factors (0.56). Overall model performance and calibration in the validation cohort was fair (0.65, 95% CI 0.64 to 0.66) but did not perform sufficiently well as a screening tool, demonstrating high false-positive/false-negative rates at clinically relevant thresholds.

CONCLUSIONS

Unplanned 90-day hospital readmission is common. Pre-existing illness indices are better predictors of readmission than acute illness factors. Identifying additional patient-centred drivers of readmission may improve risk prediction models. Improved understanding of risk factors that are amenable to intervention could improve the clinical and cost-effectiveness of post-ICU care and rehabilitation.

Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed

OBJECTIVES

Nasal carriers of Staphylococcus (S.) aureus (MRSA and MSSA) have an increased risk for healthcare-associated infections. There are currently limited national screening policies for the detection of S. aureus despite the World Health Organization's recommendations. This study aimed to evaluate the diagnostic performance of molecular and culture techniques in S. aureus screening, determine the cause of any discrepancy between the diagnostic techniques, and model the potential effect of different diagnostic techniques on S. aureus detection in orthopaedic patients.

METHODS

Paired nasal swabs for polymerase chain reaction (PCR) assay and culture of S. aureus were collected from a study population of 273 orthopaedic outpatients due to undergo joint arthroplasty surgery.

RESULTS

The prevalence of MSSA nasal colonization was found to be between 22.4% to 35.6%. The current standard direct culturing methods for detecting S. aureus significantly underestimated the prevalence (p = 0.005), failing to identify its presence in approximately one-third of patients undergoing joint arthroplasty surgery.

CONCLUSION

Modelling these results to national surveillance data, it was estimated that approximately 5000 to 8000 S. aureus surgical site infections could be prevented, and approximately $140 million to $950 million (approximately £110 million to £760 million) saved in treatment costs annually in the United States and United Kingdom combined, by using alternative diagnostic methods to direct culture in preoperative S. aureus screening and eradication programmes.Cite this article: S. T. J. Tsang, M. P. McHugh, D. Guerendiain, P. J. Gwynne, J. Boyd, A. H. R. W. Simpson, T. S. Walsh, I. F. Laurenson, K. E. Templeton. Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed. Bone Joint Res 2018;7:79-84. DOI: 10.1302/2046-3758.71.BJR-2017-0175.R1.

Early troponin I in critical illness and its association with hospital mortality: a cohort study

Background

Troponin I (TnI) is frequently elevated in critical illness, but its interpretation is unclear. Our primary objectives in this study were to evaluate whether TnI is associated with hospital mortality and if this association persists after adjusting for potential confounders. We also aimed to ascertain whether addition of TnI to the Acute Physiological and Chronic Health Evaluation II (APACHE II) risk prediction model improves its performance in general intensive care unit (ICU) populations.

Methods

We performed an observational cohort study with independent derivation and validation cohorts in two general level 3 ICU departments in the United Kingdom. The derivation cohort was a 4.5-year cohort (2010–2014) of general ICU index admissions (n = 1349). The validation cohort was used for secondary analysis of a prospective study dataset (2010) (n = 145). The primary exposure was plasma TnI concentration taken within 24 h of ICU admission. The primary outcome was hospital mortality. We performed multivariate regression, adjusting for components of the APACHE II model. We derived the risk prediction score from the multivariable model with TnI.

Results

Hospital mortality was 37.3% (n = 242) for patients with detectable TnI, compared with 14.6% (n = 102) for patients without detectable TnI. There was a significant univariate association between TnI and hospital mortality (OR per doubling TnI 1.16, 95% CI 1.13–1.20, p < 0.001). This persisted after adjustment for APACHE II model components (TnI OR 1.05, 95% CI 1.01–1.09, p = 0.003). TnI correlated most strongly with the acute physiology score (APS) component of APACHE II (r = 0.39). Addition of TnI to the APACHE II model did not improve discrimination (APACHE II concordance statistic [c-index] 0.835, 95% CI 0.811–0.858; APACHE II + TnI c-index 0.837, 95% CI 0.813–0.860; p = 0.330) or other measures of model performance.

Conclusions

TnI is an independent predictor of hospital mortality and correlates most highly with the APS component of APACHE II. It does not improve risk prediction. We would not advocate the adoption of routine troponin analysis on admission to ICU, and we recommend that troponin be measured only if clinically indicated.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-017-1800-4) contains supplementary material, which is available to authorized users.

Five-Year Mortality and Hospital Costs Associated with Surviving Intensive Care

RATIONALE

Survivors of critical illness experience significant morbidity, but the impact of surviving the intensive care unit (ICU) has not been quantified comprehensively at a population level.

OBJECTIVES

To identify factors associated with increased hospital resource use and to ascertain whether ICU admission was associated with increased mortality and resource use.

METHODS

Matched cohort study and pre/post-analysis using national linked data registries with complete population coverage. The population consisted of patients admitted to all adult general ICUs during 2005 and surviving to hospital discharge, identified from the Scottish Intensive Care Society Audit Group registry, matched (1:1) with similar hospital control subjects. Five-year outcomes included mortality and hospital resource use. Confounder adjustment was based on multivariable regression and pre/post within-individual analyses.

MEASUREMENTS AND MAIN RESULTS

Of 7,656 ICU patients, 5,259 survived to hospital discharge (5,215 [99.2%] matched to hospital control subjects). Factors present before ICU admission (comorbidities/pre-ICU hospitalizations) were stronger predictors of hospital resource use than acute illness factors. In the 5 years after the initial hospital discharge, compared with hospital control subjects, the ICU cohort had higher mortality (32.3% vs. 22.7%; hazard ratio, 1.33; 95% confidence interval, 1.22-1.46; P < 0.001), used more hospital resources (mean hospital admission rate, 4.8 vs. 3.3/person/5 yr), and had 51% higher mean 5-year hospital costs ($25,608 vs. $16,913/patient). Increased resource use persisted after confounder adjustment (P < 0.001) and using pre/post-analyses (P < 0.001). Excess resource use and mortality were greatest for younger patients without significant comorbidity.

CONCLUSIONS

This complete, national study demonstrates that ICU survivorship is associated with higher 5-year mortality and hospital resource use than hospital control subjects, representing a substantial burden on individuals, caregivers, and society.

Anemia and blood transfusion in the critically ill patient with cardiovascular disease

This article is one of ten reviews selected from the Annual Update in Intensive Care and Emergency Medicine 2017. Other selected articles can be found online at http://ccforum.com/series/annualupdate2017 . Further information about the Annual Update in Intensive Care and Emergency Medicine is available from http://www.springer.com/series/8901 .

Effect of day of the week on short- and long-term mortality after emergency general surgery

BACKGROUND

The effect of day of the week on outcome after surgery is the subject of debate. The aim was to determine whether day of the week of emergency general surgery alters short- and long-term mortality.

METHODS

This was an observational study of all patients undergoing emergency general surgery in Scotland between 1 January 2005 and 31 December 2007, followed to 2012. Multilevel logistic and Cox proportional hazards regression were used to assess the effect of day of the week of surgery on outcome after adjustment for case mix and risk factors. The primary outcome was perioperative mortality; the secondary outcome was overall survival.

RESULTS

A total of 50 844 patients were identified, of whom 31 499 had an emergency procedure on Monday to Thursday and 19 345 on Friday to Sunday. Patients undergoing surgery at the weekend were younger (mean 45·9 versus 47·5 years; P < 0·001) and had fewer co-morbidities, but underwent riskier and/or more complex procedures (P < 0·001). Patients who had surgery at the weekend were more likely to have been operated on sooner than those who had weekday surgery (mean time from admission to operation 1·2 versus 1·6 days; P < 0·001). No difference in perioperative mortality (odds ratio 1·00, 95 per cent c.i. 0·89 to 1·13; P = 0·989) or overall survival (hazard ratio 1·01, 0·97 to 1·06; P = 0·583) was observed when surgery was performed at the weekend. There was no difference in overall survival after surgery undertaken on any particular day compared with Wednesday; a borderline reduction in perioperative mortality was seen on Tuesday.

CONCLUSION

There was no difference in short- or long-term mortality following emergency general surgery at the weekend, compared with mid-week.

pRotective vEntilation with veno-venouS lung assisT in respiratory failure: A protocol for a multicentre randomised controlled trial of extracorporeal carbon dioxide removal in patients with acute hypoxaemic respiratory failure

One of the few interventions to demonstrate improved outcomes for acute hypoxaemic respiratory failure is reducing tidal volumes when using mechanical ventilation, often termed lung protective ventilation. Veno-venous extracorporeal carbon dioxide removal (vv-ECCO₂R) can facilitate reducing tidal volumes. pRotective vEntilation with veno-venouS lung assisT (REST) is a randomised, allocation concealed, controlled, open, multicentre pragmatic trial to determine the clinical and cost-effectiveness of lower tidal volume mechanical ventilation facilitated by vv-ECCO₂R in patients with acute hypoxaemic respiratory failure. Patients requiring intubation and mechanical ventilation for acute hypoxaemic respiratory failure will be randomly allocated to receive either vv-ECCO₂R and lower tidal volume mechanical ventilation or standard care with stratification by recruitment centre. There is a need for a large randomised controlled trial to establish whether vv-ECCO₂R in acute hypoxaemic respiratory failure can allow the use of a more protective lung ventilation strategy and is associated with improved patient outcomes.

16S pan-bacterial PCR can accurately identify patients with ventilator-associated pneumonia

Ventilator-associated pneumonia (VAP) remains a challenge to intensive care units, with secure diagnosis relying on microbiological cultures that take up to 72 hours to provide a result. We sought to derive and validate a novel, real-time 16S rRNA gene PCR for rapid exclusion of VAP. Bronchoalveolar lavage (BAL) was obtained from two independent cohorts of patients with suspected VAP. Patients were recruited in a 2-centre derivation cohort and a 12-centre confirmation cohort. Confirmed VAP was defined as growth of >10⁴ colony forming units/ml on semiquantitative culture and compared with a 16S PCR assay. Samples were tested from 67 patients in the derivation cohort, 10 (15%) of whom had confirmed VAP. Using cycles to cross threshold (C_t) values as the result of the 16S PCR test, the area under the receiver operating characteristic (ROC) curve (AUROC) was 0.94 (95% CI 0.86 to 1.0, p<0.0001). Samples from 92 patients were available from the confirmation cohort, 26 (28%) of whom had confirmed VAP. The AUROC for C_t in this cohort was 0.89 (95% CI 0.83 to 0.95, p<0.0001). This study has derived and assessed the diagnostic accuracy of a novel application for 16S PCR. This suggests that 16S PCR in BAL could be used as a rapid test in suspected VAP and may allow better stewardship of antibiotics.

Exercise rehabilitation following intensive care unit discharge for recovery from critical illness: executive summary of a Cochrane Collaboration systematic review

Skeletal muscle wasting and weakness are major complications of critical illness and underlie the profound physical and functional impairments experienced by survivors after discharge from the intensive care unit (ICU). Exercise-based rehabilitation has been shown to be beneficial when delivered during ICU admission. This review aimed to determine the effectiveness of exercise rehabilitation initiated after ICU discharge on primary outcomes of functional exercise capacity and health-related quality of life. We sought randomized controlled trials, quasi-randomized controlled trials, and controlled clinical trials comparing an exercise intervention commenced after ICU discharge vs. any other intervention or a control or 'usual care' programme in adult survivors of critical illness. Cochrane Central Register of Controlled Trials, Medical Literature Analysis and Retrieval System Online (MEDLINE), Excerpta Medica Database, and Cumulative Index to Nursing and Allied Health Literature databases were searched up to February 2015. Dual, independent screening of results, data extraction, and quality appraisal were performed. We included six trials involving 483 patients. Overall quality of evidence for both outcomes was very low. All studies evaluated functional exercise capacity, with three reporting positive effects in favour of the intervention. Only two studies evaluated health-related quality of life and neither reported differences between intervention and control groups. Meta-analyses of data were precluded due to variation in study design, types of interventions, and selection and reporting of outcome measurements. We were unable to determine an overall effect on functional exercise capacity or health-related quality of life of interventions initiated after ICU discharge for survivors of critical illness. Findings from ongoing studies are awaited. Future studies need to address methodological aspects of study design and conduct to enhance rigour, quality, and synthesis.

The cyclin-dependent kinase inhibitor AT7519 accelerates neutrophil apoptosis in sepsis-related acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a neutrophil-dominant disorder with no effective pharmacological therapies. While the cyclin-dependent kinase inhibitor AT7519 induces neutrophil apoptosis to promote inflammation resolution in preclinical models of lung inflammation, its potential efficacy in ARDS has not been examined. Untreated peripheral blood sepsis-related ARDS neutrophils demonstrated prolonged survival after 20 hours in vitro culture. AT7519 was able to override this phenotype to induce apoptosis in ARDS neutrophils with reduced expression of the pro-survival protein Mcl-1. We demonstrate the first pharmacological compound to induce neutrophil apoptosis in sepsis-related ARDS, highlighting cyclin-dependent kinase inhibitors as potential novel therapeutic agents.