Bi-directional relationships between physical activity and stress in college aged students: a brief report.

Young adults entering college are exposed to new and ever-changing stressors that powerfully affect health and academic achievement. While engaging in physical activity can help to manage the experience of stress, stress itself is an important barrier to activity. The purpose of this study is to examine the bidirectional relationships between physical activity and momentary stress among college students. We further examined whether these relationships were modified by trait mindfulness. Undergraduate students (N = 61) completed a single measure of trait mindfulness and up to 6 daily ecological momentary assessments of stress for one week while wearing an ActivPAL accelerometer. Activity variables were aggregated in the 30, 60, and 90 min before and following each stress survey. Multilevel models revealed significant negative relationships between stress ratings and total volume of activity both preceding and following the survey. Mindfulness did not modify these relationships but was independently and negatively related to momentary reports of stress. These results underscore the importance of developing activity programming for college students that addresses stress as a powerful and dynamic barrier to behavior change.

Associations between patterns of physical activity, pain intensity, and interference among older adults with chronic pain: a secondary analysis of two randomized controlled trials.

Background: Clinical management of chronic pain often includes recommendations to engage in physical activity (PA), though there are little data on the interplay between pain symptoms and key aspects of PA participation (e.g., intensity and bout duration) among older adults. Herein we investigate the longitudinal relationships between changes in PA behavior and changes in pain intensity and interference among low-active older adults with obesity and chronic pain. Methods: Participants (N = 41) were enrolled in two randomized pilot trials wherein they were assigned to an intervention focused on participation in frequent PA across the day, or to a low-contact control. Participants completed the 3-item PROMIS pain intensity scale and 8-item PROMIS pain interference scale before and after the interventions. Participants also wore an ActivPAL accelerometer for 7 days before and during the final week of the interventions. Results: A series of linear regression analyses demonstrated that increased time spent stepping at a high-light intensity in very short bouts was associated with increased pain intensity scores. By contrast, increased time spent stepping at a high-light intensity in bouts of 5-20 min was associated with reductions in pain intensity and interference scores. Increased time spent stepping at a moderate intensity overall was associated with reduced pain intensity scores, and time spent stepping at a moderate intensity for 10-20 min associated with reduced pain interference. Conclusion: These findings suggest older adults with chronic pain may benefit by moving at high-light or moderate intensities in brief bouts of at least 5 min in duration.

A remote group-mediated daylong physical activity intervention for older adults with chronic pain: Results of the MORPH-II randomized pilot trial.

Chronic pain is a debilitating condition that affects many older adults who often have limited access to non-pharmacological pain management strategies. One potentially effective and novel lifestyle medicine for chronic pain involves increasing physical activity through frequent movement across the day, thereby also decreasing the presence of extended sedentary bouts. The MORPH-II pilot randomized controlled refinement trial iterated on the MORPH trial, which was a first-of-its-kind group-mediated daylong physical activity (DPA) intervention for older adults with chronic pain rooted in social cognitive and self-determination theories and supported by an mHealth toolset designed to foster social connection and awareness of physical activity patterns. MORPH-II was delivered fully remotely via videoconference software and supported by a technology kit comprising an iPad, activity monitor, and wireless weight scale. It was also implemented a refined coaching model designed to help participants better understand their own patterns of activity. A total of 44 participants were randomized to receive the 12-week group-mediated DPA intervention or to a low-contact control. Qualitative interviews suggest the program was well-received by participants and that participants developed an understanding of how patterns of physical activity related to their pain symptoms. Participants also highlighted several additional areas for refinement related to the coaching model and feedback provided within the mHealth app. Analyses of covariance, controlling for baseline values, revealed a small effect (η 2 = 0.01) on pain intensity favoring the intervention condition, though both groups improved during the study period. There was a large effect favoring the intervention condition on ActivPAL-assessed average daily steps (η 2 = 0.23) and postural shifts (η 2 = 0.24). Control participants spent less time in short sedentary bouts (η 2 = 0.09), and there was a small effect (η 2 = 0.02) indicating intervention participants spent less time in extended sedentary bouts. Finally, relative to control, intervention participants demonstrated a moderate improvement in autonomy satisfaction (η 2 = 0.05), relatedness frustration (η 2 = 0.05), and competence frustration (η 2 = 0.06), and a large magnitude improvement in competence satisfaction (η 2 = 0.22). These findings indicate that the MORPH-II intervention was feasible and acceptable, and may positively impact steps, postural breaks, and several key domains of basic psychological needs detailed in self-determination theory.

Changes in infant porcine pulmonary tissue oxylipins induced by cardiopulmonary bypass.

BACKGROUND: Oxylipins are metabolites derived from fatty acids such as arachidonic acid (AA) and are key mediators in inflammation, host defense, and tissue injury. Serum oxylipins increase in adults after cardiopulmonary bypass (CPB) but tissue-level changes are poorly defined. The objective of this study was to characterize pulmonary tissue oxylipins in an infant porcine model of CPB with deep hypothermic circulatory arrest (DHCA). METHODS: Infant pigs underwent CPB with DHCA. Controls received anesthesia only. Right upper and lower lobes of the lung underwent oxylipin analysis via liquid chromatography-tandem mass spectrometry. One-way ANOVA was utilized to assess differences in oxylipin concentrations across groups, followed by pairwise comparisons. RESULTS: AA and multiple AA metabolites via cytochrome P450 (CYP450), lipoxygenase (LOX), and cyclooxygenase (COX) pathways were significantly increased in the upper and lower lobe of pigs exposed to CPB/DHCA as compared to controls. Multiple prostaglandin metabolites produced via COX were also significantly elevated in the lower lobes of control animals. CONCLUSIONS: CPB/DHCA induces a significant increase in pulmonary tissue AA, with subsequent metabolism via COX, LOX, and CYP450 pathways. Interestingly, prostaglandins were also elevated in the lower lobes of the controls, suggesting a mechanism separate from CPB/DHCA. Future oxylipin studies are needed to better understand CPB-induced acute lung injury. IMPACT: CPB/DHCA and, to a lesser extent, lung region influence pulmonary tissue-level AA metabolite production. Inflammatory mediator AA metabolites have been noted in previous studies to increase following CPB; however, this is the first study to look at pulmonary tissue-level differences following CPB/DHCA. Increases in many AA metabolites, including LOX- and CYP450-derived products, were seen in both upper and lower lobe of piglets following CPB/DHCA. COX-derived prostaglandin metabolites were increased not only in CPB upper and lower lobe but also in mechanically ventilated control lower lobe, suggesting an additional, separate mechanism from CPB/DCHA.

Metabolomic profiling demonstrates evidence for kidney and urine metabolic dysregulation in a piglet model of cardiac surgery-induced acute kidney injury.

Acute kidney injury (AKI) is a common cause of morbidity after congenital heart disease surgery. Progress on diagnosis and therapy remains limited, however, in part due to poor mechanistic understanding and a lack of relevant translational models. Metabolomic approaches could help identify novel mechanisms of injury and potential therapeutic targets. In the present study, we used a piglet model of cardiopulmonary bypass with deep hypothermic circulatory arrest (CPB/DHCA) and targeted metabolic profiling of kidney tissue, urine, and serum to evaluate metabolic changes specific to animals with histological acute kidney injury. CPB/DHCA animals with acute kidney injury were compared with those without acute kidney injury and mechanically ventilated controls. Acute kidney injury occurred in 10 of 20 CPB/DHCA animals 4 h after CPB/DHCA and 0 of 7 control animals. Injured kidneys showed a distinct tissue metabolic profile compared with uninjured kidneys (R2 = 0.93, Q2 = 0.53), with evidence of dysregulated tryptophan and purine metabolism. Nine urine metabolites differed significantly in animals with acute kidney injury with a pattern suggestive of increased aerobic glycolysis. Dysregulated metabolites in kidney tissue and urine did not overlap. CPB/DHCA strongly affected the serum metabolic profile, with only one metabolite that differed significantly with acute kidney injury (pyroglutamic acid, a marker of oxidative stress). In conclusion, based on these findings, kidney tryptophan and purine metabolism are candidates for further mechanistic and therapeutic investigation. Urine biomarkers of aerobic glycolysis could help diagnose early acute kidney injury after CPB/DHCA and warrant further evaluation. The serum metabolites measured at this early time point did not strongly differentiate based on acute kidney injury.NEW & NOTEWORTHY This project explored the metabolic underpinnings of postoperative acute kidney injury (AKI) following pediatric cardiac surgery in a translationally relevant large animal model of cardiopulmonary bypass with deep hypothermic circulatory arrest. Here, we present novel evidence for dysregulated tryptophan catabolism and purine catabolism in kidney tissue and increased urinary glycolysis intermediates in animals who developed histological AKI. These pathways represent potential diagnostic and therapeutic targets for postoperative AKI in this high-risk population.

Regional lung metabolic profile in a piglet model of cardiopulmonary bypass with circulatory arrest.

INTRODUCTION: Acute lung injury is common following cardiopulmonary bypass and deep hypothermic circulatory arrest for congenital heart surgery with the most severe injury in the dorsocaudal lung. Metabolomics offers promise in deducing mechanisms of disease states, providing risk stratification, and understanding therapeutic responses in regards to CPB/DHCA related organ injury. OBJECTIVES: Using an infant porcine model, we sought to determine the individual and additive effects of CPB/DHCA and lung region on the metabolic fingerprint, metabolic pathways, and individual metabolites in lung tissue. METHODS: Twenty-seven infant piglets were divided into two groups: mechanical ventilation + CPB/DHCA (n = 20) and mechanical ventilation only (n = 7). Lung tissue was obtained from dorsocaudal and ventral regions. Targeted analysis of 235 metabolites was performed using HPLC/MS-MS. Data was analyzed using Principal Component Analysis (PCA), Partial Least Square Discriminant Analysis (PLS-DA), ANOVA, and pathway analysis. RESULTS: Profound metabolic differences were found in dorsocaudal compared to ventral lung zones by PCA and PLS-DA (R2 = 0.7; Q2 = 0.59; p < 0.0005). While overshadowed by the regional differences, some differences by exposure to CPB/DHCA were seen as well. Seventy-four metabolites differed among groups and pathway analysis revealed 20 differential metabolic pathways. CONCLUSION: Our results demonstrate significant metabolic disturbances between dorsocaudal and ventral lung regions during supine mechanical ventilation with or without CPB/DHCA. CPB/DHCA also leads to metabolic differences and may have additive effects to the regional disturbances. Most pathways driving this pathology are involved in energy metabolism and the metabolism of amino acids, carbohydrates, and reduction-oxidation pathways.

Tissue alkaline phosphatase activity and expression in an experimental infant swine model of cardiopulmonary bypass with deep hypothermic circulatory arrest.

BACKGROUND: Infant cardiac surgery with cardiopulmonary bypass results in decreased circulating alkaline phosphatase that is associated with poor postoperative outcomes. Bovine intestinal alkaline phosphatase infusion represents a novel therapy for post-cardiac surgery organ injury. However, the effects of cardiopulmonary bypass and bovine-intestinal alkaline phosphatase infusion on tissue-level alkaline phosphatase activity/expression are unknown. METHODS: Infant pigs (n = 20) underwent cardiopulmonary bypass with deep hypothermic circulatory arrest followed by four hours of intensive care. Seven control animals underwent mechanical ventilation only. Cardiopulmonary bypass/deep hypothermic circulatory arrest animals were given escalating doses of bovine intestinal alkaline phosphatase infusion (0-25 U/kg/hr.; n = 5/dose). Kidney, liver, ileum, jejunum, colon, heart and lung were collected for measurement of tissue alkaline phosphatase activity and mRNA. RESULTS: Tissue alkaline phosphatase activity varied significantly across organs with the highest levels found in the kidney and small intestine. Cardiopulmonary bypass with deep hypothermic circulatory arrest resulted in decreased kidney alkaline phosphatase activity and increased lung alkaline phosphatase activity, with no significant changes in the other organs. Alkaline phosphatase mRNA expression was increased in both the lung and the ileum. The highest dose of bovine intestinal alkaline phosphatase resulted in increased kidney and liver tissue alkaline phosphatase activity. CONCLUSIONS: Changes in alkaline phosphatase activity after cardiopulmonary bypass with deep hypothermic circulatory arrest and bovine intestinal alkaline phosphatase delivery are tissue specific. Kidneys, lung, and ileal alkaline phosphatase appear most affected by cardiopulmonary bypass with deep hypothermic circulatory arrest and further research is warranted to determine the mechanism and biologic importance of these changes.

Alkaline Phosphatase Treatment of Acute Kidney Injury in an Infant Piglet Model of Cardiopulmonary Bypass with Deep Hypothermic Circulatory Arrest.

Acute kidney injury (AKI) is associated with prolonged hospitalization and mortality following infant cardiac surgery, but therapeutic options are limited. Alkaline phosphatase (AP) infusion reduced AKI in phase 2 sepsis trials but has not been evaluated for cardiac surgery-induced AKI. We developed a porcine model of infant cardiopulmonary bypass (CPB) with deep hypothermic circulatory arrest (DHCA) to investigate post-CPB/DHCA AKI, measure serum/renal tissue AP activity with escalating doses of AP infusion, and provide preliminary assessment of AP infusion for prevention of AKI. Infant pigs underwent CPB with DHCA followed by survival for 4 h. Groups were treated with escalating doses of bovine intestinal AP (1, 5, or 25U/kg/hr). Anesthesia controls were mechanically ventilated for 7 h without CPB. CPB/DHCA animals demonstrated histologic and biomarker evidence of AKI as well as decreased serum and renal tissue AP compared to anesthesia controls. Only high dose AP infusion significantly increased serum or renal tissue AP activity. Preliminary efficacy evaluation demonstrated a trend towards decreased AKI in the high dose AP group. The results of this dose-finding study indicate that AP infusion at the dose of 25U/kg/hr corrects serum and tissue AP deficiency and may prevent AKI in this piglet model of infant CPB/DHCA.

A More Rapid, Rapid Response.

OBJECTIVES: Critical care physicians' standard for arrival to a rapid response team activation is 10 minutes or less at this institution. This study proposes that a FaceTime (Apple, Cupertino, CA) video call between the staff at the bedside and the critical care physician will allow the implementation of potentially life-saving therapies earlier than the current average response (4.5 min). DESIGN: Prospective cohort study. SETTING: Freestanding, tertiary-care children's hospital. PATIENTS: Pediatric patients ages 0-17. INTERVENTIONS: Six units were chosen as matched pairs. In the telemedicine units, after notification of an rapid response team, the critical care intensivist established a FaceTime video call with the nurse at the bedside and gathered history, visually assessed the patient, and suggested interventions. Simultaneously, the rapid response nurse, respiratory therapist, and fellow were dispatched to respond to the bedside. After the video call, the intensivist also reported to the bedside. The control units followed the standard rapid response team protocol: the intensivist physically responded to the bedside. Differences in response time, number of interventions, Pediatric Early Warning System scores, and disposition were measured, and the PICU course of those transferred was evaluated. MEASUREMENTS AND MAIN RESULTS: The telemedicine group's average time to establish FaceTime interface was 2.6 minutes and arrival at bedside was 3.7 minutes. The control group average arrival time was 3.6 minutes. The difference between FaceTime interface and physical arrival in the control group was statistically significant (p = 0.012). Physical arrival times between the telemedicine and control groups remained consistent. Fifty-eight percent of the telemedicine patients and 73% of the control patients were admitted to the PICU (p = 0.13). Of patients transferred to the PICU, there was no difference in rate of intubation, initiation of bilevel positive airway pressure, central line placement, or vasopressors. The study group averaged 1.4 interventions and a Pediatric Early Warning Signs score of 3.6. The control group averaged 1.9 interventions and a Pediatric Early Warning Signs score of 3.1 (p = not significant). CONCLUSION: FaceTime allowed the intensivist to become involved earlier and provide immediate guidance to the inpatient care teams. However, it did not clinically alter the patient course. Further study is necessary.