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Summary: Veno‐venous extracorporeal membrane oxygenation is indicated in patients with acute respiratory distress syndrome and severely impaired gas exchange despite evidence‐based lung protective ventilation, prone positioning and other parts of the standard algorithm for treating such patients. Extracorporeal support can facilitate ultra‐lung‐protective ventilation, meaning even lower volumes and pressures than standard lung‐protective ventilation, by directly removing carbon dioxide in patients needing injurious ventilator settings to maintain sufficient gas exchange. Injurious ventilation results in ventilator‐induced lung injury, which is one of the main determinants of mortality in acute respiratory distress syndrome. Marked reductions in the intensity of ventilation to the lowest tolerable levels under extracorporeal support may be achieved and could thereby potentially mitigate ventilator‐induced lung injury and theoretically patient self‐inflicted lung injury in spontaneously breathing patients with high respiratory drive. However, the benefits of this strategy may be counterbalanced by the use of continuous deep sedation and even neuromuscular blocking drugs, which may impair physical rehabilitation and impact long‐term outcomes. There are currently a lack of large‐scale prospective data to inform optimal invasive ventilation practices and how to best apply a holistic approach to patients receiving veno‐venous extracorporeal membrane oxygenation, while minimising ventilator‐induced and patient self‐inflicted lung injury. We aimed to review the literature relating to invasive ventilation strategies in patients with acute respiratory distress syndrome receiving extracorporeal support and discuss personalised ventilation approaches and the potential role of adjunctive therapies in facilitating lung protection. [ABSTRACT FROM AUTHOR]

Keywords: COVID-19; decision making; extracorporeal membrane oxygenation; ventilation EN COVID-19 decision making extracorporeal membrane oxygenation ventilation 997 1001 5 07/17/20 20200801 NES 200801 On 11 March 2020, the World Health Organization (WHO) declared novel coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), a worldwide pandemic. Insights from a trial investigating the use of ECMO for ARDS suggested that patients who were hypercapnic despite maximising lung-protective ventilation were the group of patients with the greatest mortality benefit. However, in-house ECMO cannulation is resource intensive, and delaying the decision until the patient is within the centre itself enables ECMO clinicians to better assess and personalise potentially life-saving interventions short of ECMO. [Extracted from the article]

Introduction: Peripheral atherosclerotic disease (PAD) is a condition characterized by low functional capacity which is associated with impaired free living, ambulation and low exercise tolerance. The purpose of this randomized controlled study was to evaluate whether changes in maximal walking time are associated with adaptations in cardiovascular function following supervised exercise. Methods: After ethics approval, 28 patients (63 ± 11 years) completed a graded treadmill test (2 min stages, 3·2 km h−1, with gradient increasing 2% every 2 min) until they reached level three or four on the claudication pain scale. Peak oxygen consumption was assessed on a breath-by-breath basis, by online expiratory gas analysis. Following a 40-min recovery period, peak cardiac output was measured using the non-invasive carbon dioxide rebreathing method described by Defares ( J Appl Physiol, 13, 1958, 159). Peak cardiac power output was then computed using the equation described by Cooke et al. ( Heart, 1998, 79, 289). Patients were randomly assigned to one of two groups: supervised, who exercised at the hospital twice weekly for 12 weeks or control, who received normal treatment which included encouragement to walk regularly. Results: After 12 weeks, there were no significant changes in body mass, peak oxygen consumption, peak cardiac output, peak heart rate, peak cardiac power output, respiratory exchange ratio or rating of perceived exertion in both the supervised and control group. There was a significant improvement (91%) in maximal walking distance following the supervised exercise programme. Although patients’ peak cardiovascular measurements were unchanged, the patients in the supervised exercise group were able to complete a higher workload at the end of the 12 weeks of exercise, for the equivalent demands on the circulation system. Conclusions: The findings from this study suggest that a short-term period of supervised exercise training results in an improved walking time in patients with limiting claudication because of PAD. It also demonstrated that the cardiovascular system becomes more efficient in meeting the demands of exercise. It is recommended that individuals with PAD should undertake exercise as a form of treatment. [ABSTRACT FROM AUTHOR]

Background: Erectile dysfunction (ED) and cardiovascular disease (CVD) share similar risk factors, and ED may be a marker of CVD progression. The study assessed: (i) the temporal relationship between ED and CVD and (ii) the UK incidence of ED, in patients with CVD and an age-matched control group. Design: After ethics approval, 207 patients (CVD group) attending cardiovascular rehabilitation programmes and 165 age-matched subjects (control group), from GP practices across the UK, completed up to four questionnaires [ED details, The International Index of Erectile Function (IIEF) (before and after a cardiovascular event) and ED related Quality of Life]. A health professional also completed a medical details questionnaire. Results: Erectile dysfunction was reported by 66% of individuals with CVD, with a mean duration of 5 ± 5.3 years. The control group was significantly different (p < 0.05) in both incidence (37%) and mean duration (6.6 ± 6.8 years). Only 53% of the CVD group and 43% of the control group had discussed their symptoms of ED with a health professional. The IIEF demonstrated that ED became significantly worse (p < 0.05) after a cardiovascular event, changing from moderate to severe (13–10). Conclusions: From these data, it is now evident that ED may precede a cardiovascular event by as much as 5 years. In almost half of the men with ED, there were missed opportunities to undertake a CVD risk assessment and provide an intervention, because the men did not acknowledge the problem. Men with ED should be specifically targeted for CVD preventative strategies in terms of lifestyle changes, and appropriate pharmacological treatments. [ABSTRACT FROM AUTHOR]

Heart rate variability (HRV) is a non-invasive indicator of cardiac autonomic modulation at rest. During rhythmic exercise, global HRV decreases as a function of exercise intensity. Measures reflecting sympathovagal interactions at rest do not behave as expected during exercise. This makes interpretation of HRV measures difficult, especially at higher exercise intensities. This problem is further confounded by the occurrence of non-neural oscillations in the high-frequency band due to increased respiratory effort. Alternative data treatments, such as coarse graining spectral analysis (CGSA), have demonstrated expected changes in autonomic function during exercise with some success. The separation of harmonic from fractal and/or chaotic components of HRV and study of the latter during exercise have provided further insight into cardioregulatory control. However, more research is needed. Some cross-sectional differences between HRV in athletes and controls during exercise are evident and data suggest longitudinal changes may be possible. Standard spectral HRV analysis should not be applied to exercise conditions. The use of CGSA and non-linear analyses show much promise in this area. Until further validation of these measures is carried out and clarification of the physiological meaning of such measures occurs, HRV data regarding altered autonomic control during exercise should be treated with caution. [ABSTRACT FROM AUTHOR]

Introduction: Peripheral vascular disease (PVD) is a condition characterized by atherosclerotic occlusive disease of the lower extremities, low functional capacity and low exercise tolerance. Less empirical data are available concerning the cardiovascular response to maximum exercise tests in patients with PVD. The purpose of this study was to examine cardiovascular variables in patients with peripheral vascular disease. Methods: Fifty patients (67 ± 9 years) completed an incremental exercise test (2 min stages, 3·2 km h−1, with increases of 2% every 2 min) to maximum claudication pain. Maximal oxygen consumption ( ) was assessed on a breath-by-breath basis by online expiratory gas analysis (CardiO2, Medical Graphics Co.). Blood pressure was recorded at peak exercise. Following a 30-min rest period, patients exercised at the highest level attained during the first test and cardiac output ( ) was measured using the exponential non-invasive rebreathing method. Cardiac power output peak (CPOpeak) in Watts (W), was then computed. Results: Mean ± SD values were; 13·85 ± 4·14 ml kg min−1; maximal walk time 357 ± 227 s; peak mean arterial pressure 127 ± 15 mmHg; 9·8 ± 2·39 (l min−1); CPO 2·86 ± 0·87 W. Conclusion: Patients with peripheral vascular disease demonstrate attenuated levels of cardiovascular capacity. This group of patients should be given exercise therapy in order to improve cardiovascular status and ambulatory function. [ABSTRACT FROM AUTHOR]

Automated metabolic gas analysis systems have advanced considerably over the past decade. They provide an abundance of information, which is not possible by using the traditional Douglas bag method and have become an essential tool in both physiological monitoring and in the diagnosis of cardiopulmonary disease. The validity and reliability of the different online metabolic analyzer systems are not well known, with relatively few independent studies being published. The purpose of this review was to examine and evaluate current literature regarding the validity and reliability of commercially available metabolic analyzer systems. This review reveals significant differences between the available systems in the way that they capture and process basic respiratory measurements. Online metabolic analyzer systems were found to vary significantly when compared with Douglas bag methods. These variations have the potential to introduce error into the accuracy with which the health of cardiovascular system can be assessed or training loads can be assigned. Compounding this is the fact that many automated systems are a “black box”, which makes it easy to generate data without the user having much understanding of how the data were generated. In conclusion automated metabolic analyser systems are a scientifically robust method for the evaluation of cardiopulmonary function. Individual researchers and clinicians must, however, be able to make their own decisions about the level of error that is tolerable for their individual needs. This presents a significant practical challenge in light of the speed with which technical developments in the field occur and we make some suggestions for the formulation of intersystem comparison studies. [ABSTRACT FROM AUTHOR]

ANDREWS G.J., BRODIE D.A., ANDREWS J.P., WONG J.&THOMAS B.G. (2005) Place(ment) matters: students’ clinical experiences and their preferences for first employers.International Nursing Review52, 142–153Although a significant volume of nursing research has focused on students’ experiences of clinical placements, to date, none has considered these experiences in the context of workforce recruitment and specifically how they may impact upon preferences for working for health care providers.In this context, the research used a place-sensitive geographical perspective and a combined questionnaire (n = 650), interview (n = 30) and focus group (n = 7) method to collect data on the complex range of clinical experiences which together impact upon the perceived attractiveness of different health care settings.The data identified a range of experiential factors associated with mentorship, ward management, learning opportunities and racism. An important finding was that although students’ experiences are obtained at the micro ward level, even if they may not necessarily reflect what happens throughout the hospital, they potentially impact, both positively and negatively, upon their broader perceptions of the hospital and the likelihood of seeking work there.The study highlighted a variety of issues that should be addressed by both higher education institutions and hospitals so that they may be able to provide a more consistent and positive experience for students. In the longer term, this may pay dividends through increased recruitment of new graduates. [ABSTRACT FROM AUTHOR]

To assess the reliability of heart rate variability (HRV) measures made by three commercially available analysers in healthy subjects.Twenty-nine volunteers (20 males, mean age 35 ± 13 years and nine females, mean age 29 ± 11 years) underwent repeated HRV measures under three conditions: lying supine, standing, lying supine with controlled breathing. HRV was measured simultaneously by three instruments. Reliability was assessed statistically by calculating coefficient of variation (CV), intraclass correlation coefficient (ICC) and limits of agreement (LoA).A wide range of values were found for CV (1–235%) and ICC (R = 0·16–0·99) dependent on the HRV measure assessed and the position in which the measurement was made. For the most part the analysers gave similar values in each condition. The values for CV and ICC were high but within the range reported in the literature. Values for LoA were also high and showed a wide range of values.The similarity in measures between systems indicates that biological variation and experimental error play a major role in determining the repeatability of HRV measurements. It is therefore recommended that population-specific reliability coefficients should be published where possible and that authors should take into account the reliability of measures when making sample size calculations. [ABSTRACT FROM AUTHOR]

AIM OF THE STUDY: To investigate the effects of myofascial trigger-point massage therapy to the head, neck and shoulder areas on cardiac autonomic tone. Background. No studies have reported on the effect of back massage on autonomic tone as measured by heart rate variability. This is especially relevant to the nursing profession, as massage is increasingly available as a therapy complementary to conventional nursing practice. DESIGN/METHODS: An experimental study in which subjects were initially placed in age- and sex-matched groups and then randomized to treatment or control by alternate allocation. The study involved 30 healthy subjects (16 female and 14 male, aged 32.47 +/- 1.55 years, mean +/- standard error). A 5-minute cardiac interbeat interval recording, systolic and diastolic blood pressure and subjective self-evaluations of muscle tension and emotional state were taken before and after intervention. Autonomic function was measured using time and frequency domain analysis of heart rate variability. RESULTS: Following myofascial trigger-point massage therapy there was a significant decrease in heart rate (P < 0.01), systolic blood pressure (P=0.02) and diastolic blood pressure (P < 0.01). Analysis of heart rate variability revealed a significant increase in parasympathetic activity (P < 0.01) following myofascial trigger-point massage therapy. Additionally both muscle tension and emotional state, showed significant improvement (P < 0.01). CONCLUSIONS: In normal healthy subjects myofascial trigger-point massage therapy to the head, neck and shoulder areas is effective in increasing cardiac parasympathetic activity and improving measures of relaxation. [ABSTRACT FROM AUTHOR]

Up to 50% of patients with pulmonary embolism (PE) experience hemodynamic instability and approximately 70% of patients who die of PE experience an accelerated cascade of symptoms within the first hours of onset of symptoms, thus necessitating rapid evaluation and intervention. Venoarterial extracorporeal membrane oxygenation and other ventricular assist devices, depending on the hemodynamic derangements present, may be used to stabilize patients with massive PE refractory to initial therapies or with contraindications to other interventions. Given the abnormalities in both pulmonary circulation and gas exchange caused by massive PE, venoarterial extracorporeal membrane oxygenation may be considered the preferred form of mechanical circulatory support for most patients. Venoarterial extracorporeal membrane oxygenation unloads the right ventricle and improves oxygenation, which may not only help buy time until definitive treatment but may also reduce myocardial ischemia and myocardial dysfunction. This review summarizes the available clinical data on the use of mechanical circulatory support, especially venoarterial extracorporeal membrane oxygenation, in the treatment of patients with massive PE. Furthermore, this review also provides practical guidance on the implementation of this strategy in clinical practice.

Background: Extracorporeal membrane oxygenation (ECMO) use in the United States occurs often in cardiothoracic ICUs (CTICU). It is unknown how it varies across ICU types., Methods: We identified 10 893 ECMO runs from the Extracorporeal Life Support Organization (ELSO) Registry across 2018 and 2019. Primary outcome was ECMO case volume by ICU type (CTICU vs. non-CTICU). Adjusting for pre-ECMO characteristics and case mix, secondary outcomes were on-ECMO physiologic variables by ICU location stratified by support type., Results: CTICU ECMO occurred in 65.1% and 55.1% (2018 and 2019) of total runs. A minority of total runs related to cardiac surgery procedures (CTICU: 21.7% [2018], 18% [2019]; non-CTICU: 11.2% [2018], 13% [2019]). After multivariate adjustment, non-CTICU ECMO for cardiac support associated with lower 4- and 24-h circuit flow (3.9 liters per minute [LPM] vs. 4.1 LPM, p < 0.0001; 4.1 LPM vs. 4.3 LPM, p < 0.0001); for respiratory support, lower on-ECMO mean fraction of inspired oxygen ([F i O 2 ], 67% vs. 69%, p = 0.02) and lower respiratory rate (14 vs. 15, p < 0.0001); and, for extracorporeal cardiopulmonary resuscitation (ECPR), lower ECMO flow rates at 24 h (3.5 LPM vs. 3.7 LPM, p = 0.01)., Conclusions: ECMO mostly remains in CTICUs though a minority is associated with cardiac surgery. Statistically significant but clinically minor differences in on-ECMO metrics were observed across ICU types., (© 2022 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Introduction: Although the technology used for extracorporeal life support (ECLS) has improved greatly in recent years, the application of these devices to the patient is quite complex and requires extensive training of team members both individually and together. Human factors is an area that addresses the activities, contexts, environments, and tools which interact with human behavior in determining overall system performance., Hypothesis: Analyses of the cognitive behavior of ECLS teams and individual members of these teams with respect to the occurrence of human errors may identify additional opportunities to enhance safety in delivery of ECLS., Results: The aim of this article is to support health-care practitioners who perform ECLS, or who are starting an ECLS program, by establishing standards for the safe and efficient use of ECLS with a focus on human factor issues. Other key concepts include the importance of ECLS team leadership and management, as well as controlling the environment and the system to optimize patient care., Conclusion: Expertise from other industries is extrapolated to improve patient safety through the application of simulation training to reduce error propagation and improve outcomes., (© 2021 The Authors. Artificial Organs published by International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

Extracorporeal life support (ECLS) can provide mechanical support for patients with severe life-threatening cardiac or respiratory failure. ECLS is a complex therapy that has increased in use over several decades owing to advances in technology. In concert with this growth, there is an increased need to understand the complexity of this technology to augment the effectiveness of ECLS and minimize complications such as ventilator-induced lung injury, bleeding, thrombosis, infections, and inadequate drug dosing. The purpose of this review was to discuss management strategies in adult patients receiving ECLS and provide recommendations on ventilator management, provision of adequate analgesia and sedation, treatment and prevention of infections, and anticoagulation., (© 2019 Pharmacotherapy Publications, Inc.)

Study Objectives: To compare sedative dose requirements during the 6-hour period when they are greatest in patients with severe acute respiratory distress syndrome (ARDS), as well as the time from severe ARDS onset to reach this maximum sedation exposure, between patients with severe ARDS who were managed either with or without extracorporeal membrane oxygenation (ECMO). Also, to explore factors other than ECMO use that may influence sedation requirements during this period of maximum sedation., Design: Retrospective comparative cohort analysis., Data Sources: Two academic centers, one with an adult ECMO program and one without., Patients: Consecutive adults with severe ARDS who were receiving continuous-infusion sedative therapy for at least 48 hours from the time of severe ARDS diagnosis and who were managed with ECMO (34 patients) or without ECMO (60 patients) between 2009 and 2013., Measurements and Main Results: Among patients managed with ECMO, the maximum median (interquartile range [IQR]) 6-hr sedative exposure (in midazolam equivalents) was nearly twice as high (118 [IQR 48-225] mg vs 60 [37-99] mg, p=0.004) and was reached, on average, 3 days later (4 [IQR 1-8] vs 1 [IQR 0.5-6] days, p=0.003) than patients not managed with ECMO. Patients managed with ECMO were younger, had a higher Sequential Organ Failure Assessment score, and, in the 24 hours prior to the period of maximum sedative exposure, had a higher ratio of partial pressure of oxygen in arterial blood to fraction of inspired oxygen and were more likely to receive renal replacement and high-dose fentanyl (2000 μg or more/24 hrs) therapy. An adjusted multivariable linear regression model using the natural logarithmic value of the maximum sedative exposure in a 6-hour period revealed that patient age (p=0.04) and administration of high-dose fentanyl in the 24 hours prior to the 6-hour period of maximum sedative use (p<0.0001) were each independently associated with the maximum 6-hour sedative requirement reached, but the use of ECMO was not (p=0.52)., Conclusion: Although the application of ECMO during severe ARDS resulted in a period of maximum sedation exposure that was both greater and took longer to reach, factors other than ECMO, particularly high-dose opioid administration, appeared more likely to account for this maximum sedation use. Further research surrounding sedative requirements, clearance, and patient response during ECMO is required., (© 2016 Pharmacotherapy Publications, Inc.)

Alginate-based raft-forming formulations have been marketed word-wide for over 30 years under various brand names, including Gaviscon. They are used for the symptomatic treatment of heartburn and oesophagitis, and appear to act by a unique mechanism which differs from that of traditional antacids. In the presence of gastric acid, alginates precipitate, forming a gel. Alginate-based raft-forming formulations usually contain sodium or potassium bicarbonate; in the presence of gastric acid, the bicarbonate is converted to carbon dioxide which becomes entrapped within the gel precipitate, converting it into a foam which floats on the surface of the gastric contents, much like a raft on water. Both in vitro and in vivo studies have demonstrated that alginate-based rafts can entrap carbon dioxide, as well as antacid components contained in some formulations, thus providing a relatively pH-neutral barrier. Several studies have demonstrated that the alginate raft can preferentially move into the oesophagus in place, or ahead, of acidic gastric contents during episodes of gastro-oesophageal reflux; some studies further suggest that the raft can act as a physical barrier to reduce reflux episodes. Although some alginate-based formulations also contain antacid components which can provide significant acid neutralization capacity, the efficacy of these formulations to reduce heartburn symptoms does not appear to be totally dependent on the neutralization of bulk gastric contents. The strength of the alginate raft is dependant on several factors, including the amount of carbon dioxide generated and entrapped in the raft, the molecular properties of the alginate, and the presence of aluminium or calcium in the antacid components of the formulation. Raft formation occurs rapidly, often within a few seconds of dosing; hence alginate-containing antacids are comparable to traditional antacids for speed of onset of relief. Since the raft can be retained in the stomach for several hours, alginate-based raft-forming formulations can additionally provide longer-lasting relief than that of traditional antacids. Indeed, clinical studies have shown Gaviscon is superior to placebo, and equal to or significantly better than traditional antacids for relieving heartburn symptoms. Alginate-based, raft-forming formulations have been used to treat reflux symptoms in infants and children, and in the management of heartburn and reflux during pregnancy. While Gaviscon is effective when used alone, it is compatible with, and does not interfere with the activity of antisecretory agents such as cimetidine. Even with the introduction of new antisecretory and promotility agents, alginate-rafting formulations will continue to have a role in the treatment of heartburn and reflux symptoms. Their unique non-systemic mechanism of action provides rapid and long-duration relief of heartburn and acid reflux symptoms.

In three experiments, subjects viewed two lines (arms) of dots in which one dot was shared by both arms, then judged with which arm the shared dot appeared to group. Length of an arm, density of the dots in the arm, and angle between arms were manipulated. Increasing the density of an arm increased grouping with that arm regardless of the angle between arms. Increasing the length of an arm however, increased grouping when arms met at 30 degree but not at 180 degree; intermediate angles produced intermediate effects. Advantage of the present method's simplification of the stimulus display are discussed.