Physiological Reserve Capacity Research Articles

The relationship between self-perceived fatigue, muscle endurance, and circulating markers of inflammation in participants of the Copenhagen aging and Midlife Biobank (CAMB)

BackgroundFatigue, low muscle endurance, muscle weakness and low-grade inflammation are strongly related to frailty at higher age. When signs of self-perceived fatigue and low muscle endurance are interrelated with low-grade inflammation at midlife, they might be used as early markers for frailty. This study investigated whether the interrelationships among self-perceived fatigue, muscle endurance and inflammation can be observed at midlife.MethodsA total of 965 participants of the Copenhagen Aging and Midlife Biobank (aged 52 ± 4 years, 536 males, 426 females) were assessed for self-perceived fatigue (20-item multidimensional fatigue inventory), muscle endurance (grip work), circulating markers of inflammation (hsCRP, IL-6, IL-10, TNF-alpha and IFN-γ), daily physical activity (PAS-2), body composition (%body fat assessed by bio-impedance) and self-reported health status. Participants were categorised (correcting for age and gender) according to high fatigue and/or low muscle endurance, differences in inflammatory profile between fatigue categories were assessed by ANCOVA (corrected for PAS-2, %body fat and presence of inflammatory conditions).ResultsOverall, muscle endurance, fatigue and inflammatory markers were significantly interrelated. Higher levels of hsCRP (p < 0.001), IL-6 (p < 0.001), IL-10 (p = 0.035) and TNF-alpha (p = 0.028) were observed in participants presenting both low muscle endurance and high fatigue. IFN-γ was highest in those with high fatigue but normal muscle endurance (p = 0.015).ConclusionsMiddle-aged participants with higher fatigue in combination with low muscle endurance show higher levels of inflammation, independently from physical activity, body fat and inflammatory pathology. The underlying mechanisms should be identified and future studies should also investigate whether these individuals show early signs of reduced physiological reserve capacity, which in later life come to full expression by means of frailty.

Effects of Citrus kawachiensis Peel in Frailty-like Model Mice Induced by Low Protein Nutrition Disorders

"Frailty" caused by a decline in physiological reserve capacity, chronic inflammation, and oxidative stress in the elderly has recently become a major social issue. The present study examined the effects of the peel of Citrus kawachiensis (CK), which exhibits anti-inflammatory, antioxidant, and pro-neurogenesis activities in frailty-like model mice. Male C57BL/6 mice (15 weeks old) were fed an 18% protein diet (CON), a 2.5% protein diet (PM), and PM mixed with 1% dried CK peel powder for approximately 1 month. Mice were euthanized 2 or 8 days after a single intraperitoneal administration of lipopolysaccharide (LPS) and tissues were dissected. Among peripheral tissues, muscle weight, liver weight, and blood glucose levels were significantly higher in the PM-LPS-CK group than in the PM-LPS group. In the behavioral analysis, locomotive activity was significantly lower in the PM-LPS group than in the PM group. The reduction in locomotive activity in the PM-LPS-CK group was significantly smaller than that in the PM-LPS group. The quantification of microglia in the hippocampal stratum lacunosum-moleculare revealed that increases in the PM-LPS group were significantly suppressed by the dried CK peel powder. Furthermore, the quantification of synaptic vesicle membrane proteins in the hippocampal CA3 region showed down-regulated expression in the PM-LPS group, which was significantly ameliorated by the administration of the dried CK peel powder. Collectively, these results suggest that CK inhibits inflammation and oxidative stress induced by PM and LPS in the central nervous system and peripheral tissue. Therefore, C. kawachiensis is highly effective against "frailty".

Development and the art of nutritional maintenance.

Development from early conceptus to a complex, multi-cellular organism is a highly ordered process that is dependent on an adequate supply of nutrients. During this process, the pattern of organ growth is robust, driven by a genetic blueprint and matched to anticipated body mass with high precision and with built-in physiological reserve capacity. This apparent canalisation of the developmental process is particularly sensitive to variation in environmental stimuli, such as inappropriate drug or hormone exposure, or pattern of nutrient delivery. Significant variation in any of these factors can profoundly affect fetal and neonatal growth patterns, with later detriment for physiological function and/or reserve capacity of the resultant adult, with potential health impact. This paradigm shift in science has become known as the Developmental Origins of Health and Disease (DOHaD). Over the last 30 years, many animal and clinical studies have vastly expanded our fundamental knowledge of developmental biology, particularly in the context of later effects on health. In this horizons article, we discuss DOHaD through the lens of nutritional quality (e.g. micronutrient, amino acid, NSP intake). The concept of ‘Quality’ was considered undefinable by Robert Persig in his book, ‘Zen and the Art of Motorcycle Maintenance’. Here, development and the art of nutritional maintenance will define quality in terms of the pattern of nutrient intake, the quality of development and how each interact to influence later health outcomes.

Anatomy and Histologic of Intrinsic Aging Skin

Aging is an inevitable and dynamic biological process that is characterized by the progressive deterioration of body systems and declines in physiological reserve capacity. Aging skin has distinct two types: intrinsic and extrinsic. Intrinsic changes reduce collagen production, blood flow, amount of skin lipid, and loss of rete ridges. Intrinsic aging or chronological aging is cannot be restored to the skin with characterized by sagging skin and some expression of excess wrinkling lines. Intrinsic aging changes in thickness and characteristics of the epidermis, dermis, and hypodermis. Histologically, epidermis thinner by leveling off the dermo-epidermal junction. In the dermis, collagen fibers become thicker and irregular than younger skin, reducing the elasticity of the skin, while hypodermis reduces lipid volume.

Pancreatic islet reserve in type 1 diabetes.

Type 1 diabetes (T1D) is a chronic autoimmune disease characterized by pancreatic islet βcellloss and dysfunction resulting in insulin deficiency and hyperglycemia. During a presymptomatic phase of established β cell autoimmunity, βcellloss may first be evident through assessment of βcellsecretory capacity, a measure of functional βcellmass. Reduction in pancreatic islet βcellreserve eventually manifests as impaired first-phase insulin response to glucose and abnormal glucose tolerance, which progresses until the functional capacity for βcellsecretion can no longer meet the demand for insulin to control glycemia. A functional βcellmass of ∼25% of normal may be required to avoid symptomatic T1D but is already associated with dysregulated glucagon secretion. With symptomatic T1D, stimulated C-peptide levels >0.60 ng/mL (0.200 pmol/mL) indicate the presence of clinically meaningful residual βcellfunction for contributing to glycemic control, although even higher residual C-peptide appears necessary for evidencing glucose-dependent islet β and α cell function that may contribute to maintaining (near)normal glycemia. βcellreplacement by islet transplantation can restore a physiologic reserve capacity for insulin secretion, confirming thresholds for functional βcellmass required for independence from insulin therapy.

Menopause and frailty: a scoping review

Frailty refers to the decline in physiological reserve capacity caused by the deterioration of multiple physiological systems (brain, endocrine system, immune system, and skeletal muscle), leading to increased vulnerability and decreased stress capacity. Women have a higher prevalence of frailty than men, although the epidemiological factors underlying this phenomenon are not fully understood. Menopause and menopause-related characteristics may be among the contributing factors. Hence, the purpose of this scoping review was to explore the relationship between menopause and frailty. We attempted to summarize information such as the age that menopause occurs, years since menopause, types of menopause, and hormones and inflammatory markers of frailty among postmenopausal women. PubMed, EMBASE, The Cochrane Library, the Cumulative Index to Nursing and Allied Health Literature and Web of Science, the China National Knowledge Infrastructure, the China Biomedical Literature Service System, Wanfang Database and the WeiPu (VIP) Database were searched from inception until April 3, 2019. Supplementary searches of the references, cited documents, and similar documents of the included literature were also carried out. Of 762 papers identified, 15 articles matching the criteria were included. The prevalence of frailty among postmenopausal women ranged from 5.9% to 57.3%. Existing studies suggest that menopause is associated with frailty. Early menopause, hysterectomy, low-free testosterone levels, and high C-reactive protein levels may increase the likelihood of frailty among postmenopausal women. Few original studies have explored the relationship between estrogen and frailty and the results of these studies are conflicting. Changes in hormone and inflammatory cytokine levels may mediate frailty among postmenopausal women. More in-depth research would be required to better understand the physiological and etiological mechanisms of the occurrence of frailty among postmenopausal women.

Palliative Radiation Therapy in Older Adults With Cancer: Age-Related Considerations

There are many additional considerations when treating older adults with cancer, especially in the context of palliative care. Currently, radiation therapy is underutilised in some countries and disease sites, but there is also evidence of unnecessary treatment in other contexts. Making rational treatment decisions for older adults necessitates an underlying appraisal of the person's physiological reserve capacity. This is termed ‘frailty’, and there is considerable heterogeneity in its clinical presentation, from patients who are relatively robust and suitable for standard treatment, to those who are frail and perhaps require a different approach. Frailty assessment also presents an important opportunity for intervention, when followed by Comprehensive Geriatric Assessment (CGA) in those who require it. Generally, a two-step approach, with a short initial screening, followed by CGA, is advocated in geriatric oncology guidelines. This has the potential to optimise care of the older person, and may also reverse or slow the development of frailty. It therefore has an important impact on the patient's quality of life, which is especially valued in the context of palliative care. Frailty assessment also allows a more informed discussion of treatment outcomes and a shared decision-making approach. With regards to the radiotherapy regimen itself, there are many adaptations that can better facilitate the older person, from positioning and immobilisation, to treatment prescriptions. Treatment courses should be as short as possible and take into account the older person's unique circumstances. The additional burden of travel to treatment for the patient, caregiver or family/support network should also be considered. Reducing treatments to single fractions may be appropriate, or alternatively, hypofractionated regimens. In order to enhance care and meet the demands of a rapidly ageing population, future radiation oncology professionals require education on the basic principles of geriatric medicine, as many aspects remain poorly understood.

Incomplete Healing as a Cause of Aging: The Role of Mitochondria and the Cell Danger Response.

The rate of biological aging varies cyclically and episodically in response to changing environmental conditions and the developmentally-controlled biological systems that sense and respond to those changes. Mitochondria and metabolism are fundamental regulators, and the cell is the fundamental unit of aging. However, aging occurs at all anatomical levels. At levels above the cell, aging in different tissues is qualitatively, quantitatively, and chronologically distinct. For example, the heart can age faster and differently than the kidney and vice versa. Two multicellular features of aging that are universal are: (1) a decrease in physiologic reserve capacity, and (2) a decline in the functional communication between cells and organ systems, leading to death. Decreases in reserve capacity and communication impose kinetic limits on the rate of healing after new injuries, resulting in dyssynchronous and incomplete healing. Exercise mitigates against these losses, but recovery times continue to increase with age. Reinjury before complete healing results in the stacking of incomplete cycles of healing. Developmentally delayed and arrested cells accumulate in the three stages of the cell danger response (CDR1, 2, and 3) that make up the healing cycle. Cells stuck in the CDR create physical and metabolic separation—buffer zones of reduced communication—between previously adjoining, synergistic, and metabolically interdependent cells. Mis-repairs and senescent cells accumulate, and repeated iterations of incomplete cycles of healing lead to progressively dysfunctional cellular mosaics in aging tissues. Metabolic cross-talk between mitochondria and the nucleus, and between neighboring and distant cells via signaling molecules called metabokines regulates the completeness of healing. Purinergic signaling and sphingolipids play key roles in this process. When viewed against the backdrop of the molecular features of the healing cycle, the incomplete healing model provides a new framework for understanding the hallmarks of aging and generates a number of testable hypotheses for new treatments.

ROLE of IGF-1 System in the Modulation of Longevity: Controversies and New Insights From a Centenarians' Perspective.

Human aging is currently defined as a physiological decline of biological functions in the body with a continual adaptation to internal and external damaging. The endocrine system plays a major role in orchestrating cellular interactions, metabolism, growth, and aging. Several in vivo studies from worms to mice showed that downregulated activity of the GH/IGF-1/insulin pathway could be beneficial for the extension of human life span, whereas results are contradictory in humans. In the present review, we discuss the potential role of the IGF-1 system in modulation of longevity, hypothesizing that the endocrine and metabolic adaptation observed in centenarians and in mammals during caloric restriction may be a physiological strategy for extending lifespan through a slower cell growing/metabolism, a better physiologic reserve capacity, a shift of cellular metabolism from cell proliferation to repair activities and a decrease in accumulation of senescent cells. Therefore, understanding of the link between IGF-1/insulin system and longevity may have future clinical applications in promoting healthy aging and in Rehabilitation Medicine.

Systematic review on prehabilitation in patients undergoing major abdominal surgery: Why are we failing to prove the obvious?

Objectives: The impact of surgery on postoperative physical functioning depends on the invasiveness of the procedure and the patient’s resilience, the ability to adapt and effectively respond to stressors as surgery and hospitalization. Resilience is associated with preoperative physiological reserve capacity: higher levels positively influence the impact on postoperative physical functioning. Although studies demonstrate positive effects of prehabilitation on preoperative physiological reserve capacity, conflicting results are reported concerning its postoperative effects, possibly due to different outcome measurements used. We aim to review the content and postoperative outcomes of studies investigating prehabilitation in patients undergoing abdominal surgery.

Preceding national early warnings scores among in-hospital cardiac arrests and their impact on survival

ObjectivesIn-hospital cardiac arrests (IHCAs) are often preceded by abnormal vital signs. Preceding abnormal vital signs might lower the physiological reserve capacity and therefore decrease survival after an IHCA. AimTo assess the preceding national early warning score (NEWS) and its relation to survival after an IHCA. Material and methodsAll patients ≥18years suffering an IHCA at Karolinska University Hospital between 1st January 2014 and 31st December 2015 were included. Data regarding the IHCA, patient characteristics, calculated NEWS and 30-day survival were obtained from electronic patient records. Parameters included in NEWSs were assessed up to 12h before the IHCA. Differences in survival were assessed with adjusted logistic regression models and presented as Odds Ratios with 95% Confidence Intervals (OR, 95% CI) between patients with NEWSs of 0–4 points (low) versus those with at least 5 points (moderate) and 7 points (high). Adjustments included hospital site, sex, co-morbidities, first rhythm and location of the IHCA. ResultsIn all, 358 patients suffered an IHCA, of whom 109 (30%) survived at least 30days and 296 (83%) had sufficient vital sign documentation to calculate NEWS before the IHCA. The 87 patients with a medium NEWS had a fourfold chance and those 78 with a high NEWS (22%) had an almost tenfold chance of dying after the IHCA compared to those with a low NEWS (Adjusted OR 4.43, 95% CI 1.81–10.83 and OR 9.88 95% C.I. 2.77–35.26, respectively). ConclusionThe NEWS can be a probable proxy for estimating physiological reserve capacity since high NEWS is associated to high change of death in case of an IHCA. This information can be used when discussing prognosis with patients and relatives. But even more importantly, it stresses the need for better preventive strategies in IHCAs. Strengthens and limitations with this study•Strengths include the complete information about the outcome, i.e. 30-day survival or not due to Swedish Personal Identification Numbers and registries.•Another strength is the collection of exposure data, NEWSs, was based on a strict a priori determined protocol, including only data documented in the medical record and therefore known to the staff before the IHCA.•Limitations include the use of only documented vital signs, i.e. those taken but not documented, as well as the fact that information on interventions performed but not documented in the medical file are missing.•A potential limitation is the lack of a control group with equally abnormal vital signs but no IHCA; such information would have answered the question how predictive the NEWS is for an IHCA but this is out of the scope of this study regardless.

Periarrest Modified Early Warning Score (MEWS) predicts the outcome of in-hospital cardiac arrest.

The Modified Early Warning Score (MEWS) reflects the physiological changes of cardiac arrest and has been used in identifying patient deterioration. Physiological reserve capacity is an important outcome predictor, but is seldom reported due to recording limitations in cardiac arrest patients. The aim of the study was to evaluate whether periarrest MEWS could be a further prognostic factor in in-hospital cardiac arrest. This was a retrospective cohort study of nontrauma adult patients who had experienced in-hospital cardiac arrest during emergency department stays at an urban, 2600-bed tertiary medical center in Taiwan from February 2011 to July 2013. Data regarding patients' characteristics, Charlson Comorbidity Score, MEWS score before events, mode of arrest, and outcome details were extracted following the Utstein guidelines for uniform reporting of cardiac arrest. During the 30-month period, 234 patients suffered in-hospital cardiac arrest during emergency department stays, and 99 patients with periarrest MEWS were included in the final analysis. The MEWS at triage did not differ significantly between survival-to-discharge and mortality groups (3.42±2.2 vs. 4.02±2.65, p=0.811). Periarrest MEWS was lower in the survival-to-discharge group (4.41±2.28 vs. 5.82±2.84, p=0.053). In multivariate logistic regression analysis, periarrest MEWS was an independent predictors for survival to discharge. A rise in periarrest MEWS reduced the chance of survival to discharge by 0.77-fold (95% confidence interval: 0.60-0.97, p=0.028). The simplest MEWS system not only can be used as a prevention measure, but the periarrest MEWS could also be considered as an independent predictor of mortality after in-hospital cardiac arrest.

Sex comparisons in muscle sympathetic nerve activity and arterial pressure oscillations during progressive central hypovolemia.

Increased tolerance to central hypovolemia is generally associated with greater sympathoexcitation, high-frequency oscillatory patterns of mean arterial pressure (MAP), and tachycardia. On average, women are less tolerant to central hypovolemia than men; however, the autonomic mechanisms governing these comparisons are not fully understood. We tested the hypothesis that women with relatively high tolerance (HT) to central hypovolemia would display similar physiological reserve capacity for sympathoexcitation and oscillations in MAP at presyncope compared to HT men. About 10 men and five women were exposed to progressive lower body negative pressure (LBNP) until the presence of presyncopal symptoms. Based on our previous classification system, all subjects were classified as HT because they completed at least −60 mmHg LBNP. Muscle sympathetic serve activity (MSNA) was measured directly from the peroneal nerve via microneurography and arterial pressure (AP) was measured at the finger by photoplethysmography. LBNP time to presyncope was less (P < 0.01) in women (1727 ± 70 sec) than in men (2022 ± 201 sec). At presyncope, average MSNA in men (50 ± 12 bursts/min) and women (51 ± 7 bursts/min) was similar (P = 0.87). Coincident with similar stroke volume (SV) at presyncope, women had similar MAP and heart rates. However, women had less physiological reserve capacity for SV, AP-MSNA coherence, and oscillations in the high-frequency (HF) components of arterial pressure compared to men. Contrary to our hypothesis, lower tolerance to central hypovolemia in women was not associated with sympathoexcitation, but can be explained, in part by lower physiological reserve to elicit oscillatory patterns in AP, maintenance of AP-MSNA coherence and SV when compared to men.

Gender differences in muscle sympathetic nerve activity and arterial pressure oscillations during progressive central hypovolemia (680.2)

INTRODUCTION: Increased tolerance to central hypovolemia is generally associated with greater oscillatory patterns of mean arterial pressur (MAP) and greater physiological reserve capacity. We tested the hypothesis that women with high tolerance (HT) to hypovolemia would display similar physiological reserve capacity for tachycardia, sympathoexcitation, oscillations in MAP at pre‐syncope compared to men. METHODS: 9 men and 4 women were exposed to progressive lower body negative pressure (LBNP) until presyncope. All subjects were classified as HT because they completed at least ‐60 mmHg level of lower body negative pressure (LBNP). Muscle sympathetic serve activity (MSNA) was measured via microneurography and arterial pressure was measured by photoplethysmography. RESULTS: LBNP time to presyncope was lower (P&lt;0.01) in women (1727±154 sec) than in men (2035±308 sec). At presyncope, MSNA (bursts/min) in men and women was similar (p=0.87). Coincident with smaller stroke volume (SV), women had lower MAP but similar heart rates compared with men. MAP/MSNA coherence was higher (p =0.04) in men (0.77±0.10) than women (0.67±0.04). Women had lower (p =0.06) oscillations in MAP compared to men. CONCLUSIONS: Our data corroborate the hypothesis that lower tolerance in women is not related to differences in sympathoexcitation or tachycardia, but reduced coherence (MSNA/MAP) and lower oscillatory patterns in MAP. Grant Funding Source: Department of Defense

Cardiac surgery and anesthesia approach in an elderly patient population

Due to the increase in the average life expectancy and the higher incidence of cardiovascular disease with advancing age, an increasing number of elderly patients undergo cardiac surgery today. However, advanced age is associated with decreased physiologic reserve capacity and significant comorbidities including diabetes mellitus, renal dysfunction, cerebrovascular disease and chronic lung disease. These factors and effects of systemic inflammatory response associated with cardiopulmonary bypass (CPB) on organs and systems have a greater impact on morbidity and mortality in older patients than the younger ones. As a result, for elderly patients with additional multi-systemic risks, cardiac surgery is a real trauma with its own multisystemic effects. It requires a specific and careful approach in terms of surgery and anesthesia. The adverse effects of CPB on the organ systems which are traumatized by aging and associated illnesses should be well-established and examined together. Novel pharmacological agents, surgical techniques, improved technology and perfect anesthesiology preparation, management and complete monitoring are of utmost importance for the success of cardiac surgery in elderly.

Autonomic mechanisms associated with heart rate and vasoconstrictor reserves

Hemorrhage is accompanied by baroreflex-mediated tachycardia and vasoconstriction. The difference between baseline and maximum responses is defined as the heart rate (HR) and vasoconstrictor 'reserve'. To test the hypothesis that higher HR and vasoconstrictor reserves in subjects with high tolerance (HT) to central hypovolemia is associated with greater reserve for sympathoexcitation and vagal withdrawal compared with low tolerant (LT) subjects. R-R intervals (RRI), systolic arterial pressure (SAP), estimated stroke volume, and muscle sympathetic nerve activity (MSNA) were measured during lower body negative pressure (LBNP) designed to induce pre-syncope. Subjects with tolerance ≤ 60 mmHg LBNP were classified as LT (n = 22) while subjects who tolerated LBNP levels >60 mmHg were classified as HT (n = 56). Spontaneous cardiac baroreflex sensitivity (BRS) was assessed via RRI-SAP down-down sequences. HR reserve in HT subjects (+52 ± 2 bpm) was twofold greater (P < 0.001) than that in LT subjects (+27 ± 3 bpm). Vasoconstrictor reserve in the HT group (+3.4 ± 0.5 pru) was greater (P = 0.04) than that of the LT group (+1.9 ± 0.3 pru). HT subjects demonstrated greater (P ≤ 0.03) BRS reserve (-14.2 ± 1.8 ms/mmHg) and MSNA reserve (+41 ± 2 bursts/min) compared with LT subjects (-7.4 ± 1.7 ms/mmHg and +26 ± 7 bursts/min). Our data support the hypothesis that greater physiological reserve capacity for tachycardia and vasoconstriction related to high tolerance to central hypovolemia is associated with greater reserves for sympathoexcitation and cardiac vagal withdrawal.

Reconstructive urology and geriatrics: issues in older adults

The elderly population is continuing to expand at record pace in the vast majority of countries worldwide. Many urologic conditions that necessitate reconstructive surgery occur in geriatric patients. To date, there has been a paucity of research on the effects of aging with regard to reconstructive procedures in elderly patients. This review examines factors that influence the feasibility and outcomes of reconstructive urologic surgery in older adults. Age alone has generally not been identified as a significant predictive factor for outcomes in geriatric patients undergoing surgery. Comorbid diseases associated with reduction of physiologic reserve capacity and impairments in the level of independence for activities of daily living appear to have more predictive value. Recent research has focused on defining frailty as a condition that frequently occurs in older adults and may influence clinical outcomes. A variety of cellular and tissue changes associated with aging have also been studied. Inflammatory mediators may play an important role in this process. Many urologic conditions that require reconstructive surgery occur in elderly patients. Careful planning may help to improve outcomes. However, there appear to be inherent changes associated with the physiology of normal aging that can significantly influence this process.

Estimation of physiologic ability and surgical stress (E-PASS) as a predictor of immediate outcome after elective abdominal aortic aneurysm surgery

Background The Estimation of Physiologic Ability and Surgical Stress (E-PASS) score was designed on the premise that the balance between the patient’s physiologic reserve capacity and the surgical stress inflicted at operation was important in the occurrence of postoperative complications. The aim of this study was to assess its value in predicting mortality and morbidity after open elective abdominal aortic aneurysm (AAA) repair. Methods E-PASS data items were collected prospectively in a group of 204 patients undergoing elective open AAA repair over a 6-year period. The operative morbidity and mortality rates were compared with the preoperative risk score (PRS), surgical stress score (SSS) and comprehensive risk score (CRS) of E-PASS. The group comprised 180 (88%) males and the median age was 73 (range 44 to 86) years. Results There were 13 (6%) deaths and 121 (59%) experienced a postoperative complication. As the PRS, SSS and CRS increased, the incidence of postoperative morbidity and mortality significantly increased ( P < .0001). Overall mean CRS was .52 (±.27). Mean CRS in the groups of patients who survived and died were .49 (±.24) and .98 (±26), respectively. PRS, SSS, and CRS all had extremely good predictive power for both mortality and morbidity as demonstrated by high areas under the receiver operator curve (range .799 to .953). CRS also showed a strong statistically significant association with the severity of postoperative complication ( P < .0001) and length of hospital stay ( P < .0001). Conclusions The E-PASS model appears to be a promising method of predicting death and the development of postoperative complications in patients undergoing elective open AAA surgery. It requires further validation in arterial surgery at different geographical locations.

Teleoanticipation Does Not Occur During Repeated-Sprint Exercise

The theory of teleoanticipation proposes that muscle power output is modified by a “central governor” that takes into account projected “finishing points” and afferent feedback from the muscle. It has been suggested that this allows the selection of an optimum pacing strategy that will allow completion of the task in the most efficient way while maintaining internal homeostasis and a metabolic and physiological reserve capacity. While teleoanticipation has been proposed to occur during all forms of exercise, it has not previously been investigated during repeated-sprint exercise. PURPOSE: The present study investigated the effects of varying the anticipated number of all-out sprints on repeated-sprint performance. METHODS: Six young men and women completed two trials of two sets of 3, 4-s cycling sprints (separated by 20-s passive recovery intervals), in a random order. In one trial, subjects were deceived and told that they would be performing two sets of 6, 4-s cycling sprints. In the second trial, there was no deception. Between each set of 3 sprints, subjects rested passively for 180 s. The EMG activity from the vastus lateralis, vastus medialis, rectus femoris and biceps femoris of the right leg was recorded via bipolar surface electrodes, and a MVC was performed on a specially manufactured cycle ergometer pre and immediately post exercise. RESULTS: There was no significant difference in total work performed between the two conditions in either the first (142.8 ± 22.5 vs 141.4 ±19.8 J/kg) or second set (138.6 ± 19.5 vs 139.5 ± 19.5 J/kg). Similarly, there was no significant difference in work decrement across the 3 sprints between the two conditions in either the first (4.2 ±2.5 vs 5.1 ±2.6 %) or second set (5.7 ±3.4 vs 5.5 ± 1.5 %). There was a parallel fall in muscle power output and IEMG activity during both conditions with no significant difference between conditions. CONCLUSIONS: The parallel fall in muscle power output and IEMG activity suggest that fatigue during maximal, repeated-sprint exercise is associated with centrally-mediated changes. However, this fatigue was not influenced by perception of the end point of the exercise bout.

Low-dose ethanol alters the cardiovascular, metabolic, and respiratory compensation for severe blood loss.

Compensation for hemorrhage and shock requires coordination of responses and sufficient physiologic reserve capacity of the cardiovascular, respiratory, renal, and neuroendocrine systems. Intake of ethanol (EtOH) is known to degrade physiologic response to stress. The purpose of this study was to investigate how acute EtOH exposure changes responses to severe blood loss, shock, and resuscitation. Conscious male Duncan Hartley guinea pigs were given an intraperitoneal injection of either EtOH (1 g/kg) or an equal volume of water 30 minutes before controlled hemorrhage (60% blood volume), resuscitated after 30 minutes of hypovolemia with a lactated Ringer's solution volume equal to that of the shed blood volume, and observed for 24 hours. Hemodynamic (heart rate, arterial blood pressure), clinical laboratory (arterial blood gases, glucose, lactate, hematocrit), and metabolic gas exchange (oxygen consumption, carbon dioxide production) indicators of shock were monitored. Of the animals that survived 24 hours, changes in arterial pH and lactate were significantly greater in the experiment group than in the control group. Mortality at 24 hours was 77% in the experiment group (EtOH-treated) and 42% (p = 0.39) in the control group (water-treated). Acute EtOH exposure, with blood EtOH concentration similar to legal intoxication levels, limits physiologic reserve during hemorrhagic shock and resuscitation. In survivors of shock and resuscitation, compensation is compromised and physiologic reserve is adversely affected by acute EtOH intake.