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Postoperative acute kidney injury (PO-AKI) is a common complication of major surgery that is strongly associated with short-term surgical complications and long-term adverse outcomes, including increased risk of chronic kidney disease, cardiovascular events and death. Risk factors for PO-AKI include older age and comorbid diseases such as chronic kidney disease and diabetes mellitus. PO-AKI is best defined as AKI occurring within 7 days of an operative intervention using the Kidney Disease Improving Global Outcomes (KDIGO) definition of AKI; however, additional prognostic information may be gained from detailed clinical assessment and other diagnostic investigations in the form of a focused kidney health assessment (KHA). Prevention of PO-AKI is largely based on identification of high baseline risk, monitoring and reduction of nephrotoxic insults, whereas treatment involves the application of a bundle of interventions to avoid secondary kidney injury and mitigate the severity of AKI. As PO-AKI is strongly associated with long-term adverse outcomes, some form of follow-up KHA is essential; however, the form and location of this will be dictated by the nature and severity of the AKI. In this Consensus Statement, we provide graded recommendations for AKI after non-cardiac surgery and highlight priorities for future research.

BackgroundThe standard treatment pathway for locally advanced rectal cancer is neoadjuvant chemoradiotherapy (CRT) followed by surgery. Neoadjuvant CRT has been shown to decrease physical fitness, and this decrease is associated with increased post-operative morbidity. Exercise training can stimulate skeletal muscle adaptations such as increased mitochondrial content and improved oxygen uptake capacity, both of which are contributors to physical fitness. The aims of the EMPOWER trial are to assess the effects of neoadjuvant CRT and an in-hospital exercise training programme on physical fitness, health-related quality of life (HRQoL), and physical activity levels, as well as post-operative morbidity and cancer staging.Methods/designThe EMPOWER Trial is a randomised controlled trial with a planned recruitment of 46 patients with locally advanced rectal cancer and who are undergoing neoadjuvant CRT and surgery. Following completion of the neoadjuvant CRT (week 0) prior to surgery, patients are randomised to an in-hospital exercise training programme (aerobic interval training for 6 to 9 weeks) or a usual care control group (usual care and no formal exercise training). The primary endpoint is oxygen uptake at lactate threshold ([Formula: see text] at [Formula: see text]) measured using cardiopulmonary exercise testing assessed over several time points throughout the study. Secondary endpoints include HRQoL, assessed using semi-structured interviews and questionnaires, and physical activity levels assessed using activity monitors. Exploratory endpoints include post-operative morbidity, assessed using the Post-Operative Morbidity Survey (POMS), and cancer staging, assessed by using magnetic resonance tumour regression grading.DiscussionThe EMPOWER trial is the first randomised controlled trial comparing an in-hospital exercise training group with a usual care control group in patients with locally advanced rectal cancer. This trial will allow us to determine whether exercise training following neoadjuvant CRT can improve physical fitness and activity levels, as well as other important clinical outcome measures such as HRQoL and post-operative morbidity. These results will aid the design of a large, multi-centre trial to determine whether an increase in physical fitness improves clinically relevant post-operative outcomes.Trial registrationClinicalTrials.gov NCT01914068 (received: 7 June 2013).SponsorUniversity Hospital Southampton NHS Foundation Trust.

Abstract Background The physiological responses to hypoxaemia and cellular hypoxia are poorly understood, and inter-individual differences in performance at altitude and outcome in critical illness remain unexplained. We propose a model for exploring adaptation to hypoxia in the critically ill: the study of healthy humans, progressively exposed to environmental hypobaric hypoxia (EHH). The aim of this study was to describe the spectrum of adaptive responses in humans exposed to graded EHH and identify factors (physiological and genetic) associated with inter-individual variation in these responses. Methods Design Observational cohort study of progressive incremental exposure to EHH. Setting University human physiology laboratory in London, UK (75 m) and 7 field laboratories in Nepal at 1300 m, 3500 m, 4250 m, 5300 m, 6400 m, 7950 m and 8400 m. Participants 198 healthy volunteers and 24 investigators trekking to Everest Base Camp (EBC) (5300 m). A subgroup of 14 investigators studied at altitudes up to 8400 m on Everest. Main outcome measures Exercise capacity, exercise efficiency and economy, brain and muscle Near Infrared Spectroscopy, plasma biomarkers (including markers of inflammation), allele frequencies of known or suspected hypoxia responsive genes, spirometry, neurocognitive testing, retinal imaging, pupilometry. In nested subgroups: microcirculatory imaging, muscle biopsies with proteomic and transcriptomic tissue analysis, continuous cardiac output measurement, arterial blood gas measurement, trans-cranial Doppler, gastrointestinal tonometry, thromboelastography and ocular saccadometry. Results Of 198 healthy volunteers leaving Kathmandu, 190 reached EBC (5300 m). All 24 investigators reached EBC. The completion rate for planned testing was more than 99% in the investigator group and more than 95% in the trekkers. Unique measurements were safely performed at extreme altitude, including the highest (altitude) field measurements of exercise capacity, cerebral blood flow velocity and microvascular blood flow at 7950 m and arterial blood gas measurement at 8400 m. Conclusions This study demonstrates the feasibility and safety of conducting a large healthy volunteer cohort study of human adaptation to hypoxia in this difficult environment. Systematic measurements of a large set of variables were achieved in 222 subjects and at altitudes up to 8400 m. The resulting dataset is a unique resource for the study of genotype:phenotype interactions in relation to hypoxic adaptation.

BACKGROUND: ARDS is an overwhelming systemic inflammatory process associated with significant morbidity and mortality. Several trials have evaluated the effects of pharmaconutrients, given as part of a feeding formula or as a nutritional supplement, on clinical outcomes in critical illness and ARDS. The aim of this review is to assess the effects of immunonutrition on mechanically ventilated adults with ARDS compared to the standard feeding formula. METHODS: We searched MEDLINE, EMBASE, CENTRAL, conference proceedings, and trial registries for appropriate studies up to April 2018. We performed statistical analysis according to Cochrane methodological standards. We used the GRADE approach to assess the quality of evidence for each outcome. RESULTS: We identified 10 randomized controlled trials with 1,015 participants. All of the studies compared an enteral formula or additional supplemental omega-3 fatty acids (eg, eicosapentaenoic acid, docosahexaenoic acid), γ-linolenic acid, and antioxidants. All of the studies reported mortality. For the primary outcome, there was no difference in all-cause mortality (for the longest period reported) with the use of an immunonutrition enteral formula or additional supplements of omega-3 fatty acids, γ-linolenic acid, and antioxidants (risk ratio = 0.79, 95% CI 0.59 -1.07; low-quality evidence). For the secondary outcomes, we are uncertain whether immunonutrition with omega-3 fatty acids and antioxidants improves ICU length of stay, ventilator days, and oxygenation or increases harm. CONCLUSIONS: This Cochrane meta-analysis of 10 studies of varying quality examined the effects of omega-3 fatty acids and antioxidants in adults with ARDS. This intervention may produce little or no difference in all-cause mortality between groups. We are uncertain whether immunonutrition with omega-3 fatty acids and antioxidants improves ventilator days, ICU length of stay, or oxygenation due to the very low quality of evidence. [ABSTRACT FROM AUTHOR]

Cardiopulmonary exercise testing (CPET) in hyperoxia and hypoxia has several applications, stemming from characterization of abnormal physiological response profiles associated with exercise intolerance. As altered oxygenation can impact the performance of gas-concentration and flow sensors and pulmonary gas exchange algorithms, integrated CPET system function requires validation under these conditions. Also, as oxygenation status can influence peak [Formula: see text]o2, care should be taken in the selection of work-rate incrementation rates when CPET performance is to be compared with normobaria at sea level. CPET has been used to evaluate the effects of supplemental O2 on exercise intolerance in chronic obstructive pulmonary disease, interstitial pulmonary fibrosis, and cystic fibrosis at sea level. However, identification of those CPET indices likely to be predictive of supplemental O2 outcomes for exercise tolerance at altitude in such patients is lacking. CPET performance with supplemental O2 in respiratory patients residing at high altitudes is also poorly studied. Finally, CPET has the potential to give physiological and clinical information about acute and chronic mountain sickness, high-altitude pulmonary edema, and high-altitude cerebral edema. It may also translate high-altitude acclimatization and adaptive processes in healthy individuals into intensive care medical practice. [ABSTRACT FROM AUTHOR]