High altitude respiratory physiology and patho- physiology

At high altitude, reduced atmospheric pressure causes the partial pressure of oxygen to decrease – creating an environment of hypobaric hypoxia which presents a unique set of challenges for the respiratory system. Pulmonary physiological responses such as the hypoxic ventilatory drive are essential for successful acclimatisation, whilst others such as hypoxic pulmonary vasoconstriction may be implicated in the development of altitude illnesses. Pulmonary conditions are some of the most common (e.g. high altitude cough) and also the most serious illnesses seen at altitude (e.g high altitude pulmonary oedema, HAPE). Minimising the chance of developing HAPE through planning an appropriate ascent profile should be strongly encouraged as HAPE can rapidly be fatal if left untreated. Whilst pharmacological agents such as nifedipine can help with the management of HAPE, rapid descent remains the single-most important treatment option once symptomatic. Given the increasing popularity of travelling to altitude, an awareness of how hypobaric hypoxia affects chronic respiratory conditions such as asthma and chronic obstructive pulmonary disease (COPD) is also becoming increasingly important for respiratory physician

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

The effects of neoadjuvant chemoradiotherapy and an in-hospital exercise training programme on physical fitness and quality of life in locally advanced rectal cancer patients (The EMPOWER Trial): Study protocol for a randomised controlled trial

Background: The 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/Design: The 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 ( V · o 2 at δ L ) 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. Discussion: The 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

Preparing for and Not Waiting for Surgery

Cancer surgery is an essential treatment strategy but can disrupt patients’ physical and psychological health. With worldwide demand for surgery expected to increase, this review aims to raise awareness of this global public health concern, present a stepwise framework for preoperative risk evaluation, and propose the adoption of personalised prehabilitation to mitigate risk. Perioperative medicine is a growing speciality that aims to improve clinical outcome by preparing patients for the stress associated with surgery. Preparation should begin at contemplation of surgery, with universal screening for established risk factors, physical fitness, nutritional status, psychological health, and, where applicable, frailty and cognitive function. Patients at risk should undergo a formal assessment with a qualified healthcare professional which informs meaningful shared decision-making discussion and personalised prehabilitation prescription incorporating, where indicated, exercise, nutrition, psychological support, ‘surgery schools’, and referral to existing local services. The foundational principles of prehabilitation can be adapted to local context, culture, and population. Clinical services should be co-designed with all stakeholders, including patient representatives, and require careful mapping of patient pathways and use of multi-disciplinary professional input. Future research should optimise prehabilitation interventions, adopting standardised outcome measures and robust health economic evaluation