Mouthpiece ventilation in the management of dyspnea: A single-arm pilot study.

BACKGROUND: Noninvasive ventilation may relieve dyspnea in advanced diseases, but noninvasive ventilation through mouthpiece has not been tested in palliative care. AIM: To assess the feasibility of mouthpiece ventilation in relieving dyspnea among patients with advanced disease. DESIGN: In this prospective single-arm pilot study, the change in dyspnea by mouthpiece ventilation was measured with numeric rating scale (0-10) and 100-mm visual analogue scale. Overall, benefit and adverse events of the therapy were also assessed. SETTING/PARTICIPANTS: Twenty-two patients with an advanced disease and dyspnea from the Tampere University Hospital or Pirkanmaa Hospice were treated with mouthpiece ventilation. The patients used mouthpiece ventilation as long as they preferred, but for a minimum of 5 min. RESULTS: After the treatment period lasting a median of 13.5 min, mean decrease in dyspnea was -1.1 (95 % confidence interval = -2.2 to -0.1, p = 0.034) on numeric rating scale and -11.8 mm (95 % confidence interval = -19.9 to -3.7, p = 0.006) on visual analogue scale. Nonetheless, there was a high variability in this effect between individual patients. About half of the patients found mouthpiece ventilation beneficial. No serious adverse events occurred, but dry mouth was the most common adverse event. Anxiety did not increase with mouthpiece ventilation. CONCLUSION: Mouthpiece ventilation is feasible and may relieve dyspnea in some patients with an advanced disease. Further studies are needed, and these might concentrate on stable patients in early palliative care. Before initiation, this study was registered at clinicaltrials.gov (study no. NCT03012737).

Retrospective and Predictive Investigation of Fish Kill Events.

Fish kill investigations are critical to understanding threats to aquatic ecosystems and can serve as a measure of environmental disruption as well as an early indicator of emerging disease. The goal of this study was to analyze historical data related to such events among wild fish populations in Minnesota in order to assess the quality and completeness of the data and potential trends in fish kills. After excluding events with incomplete data (e.g., in which the location was not reported), we analyzed 225 unique fish kills from 2003 to 2013 that were recorded in two Minnesota Department of Natural Resources databases. The most reported fish kills occurred during 2007 (n = 41) and during the month of June (n = 81) across all years. Centrarchid species were present in the most fish kills (138), followed by cyprinid and ictalurid species, which were present in 53 and 40 events, respectively. Environmental factors were the most common cause of death reported. Models of environmental factors revealed that the maximum nighttime land surface temperature was the most critical factor in fish mortality, followed by changes in primary productivity and human disturbances. During the course of this study, data gaps were identified, including underreporting, inconsistent investigation, and the lack of definitive diagnoses, making interpretation of our results challenging. Even so, understanding these historical trends and data gaps can be useful in generating hypotheses and advancing data collection systems for investigating future fish kills. Our study is a primer investigation of fish kills providing information on the plausible areas, seasons, and fish groups at risk that can guide active environmental monitoring and epidemiological surveillance of fishes.

Fish Community Structure and Diet Responses to Newbury Weirs in a Low-Gradient River.

Restoration projects are often implemented to address specific issues in the environment. Consequences of a restoration project, if any are measured, typically focus on direct changes to the projects focus. However, changing habitat structure likely results in changes to the environment that affect the communities living there. Rock weirs have been used for channel stabilization in many midwestern rivers. Previous research in a southern Illinois river found that weirs benefitted aquatic macroinvertebrate and riparian bird communities by enhancing habitat heterogeneity and insect emergence production. We hypothesized that fishes would also benefit from weirs through enhanced habitat and food availability. We collected fishes in the Cache River in southern Illinois using hand nets, seines, and electroshocking at sites where weirs had been installed and at non-weir sites. Gut contents were identified and individual food items measured. Fish species richness, but not diversity, was higher at weir sites. Fish communities also differed between site types, with benthic feeders characterizing weir sites. Gut content biomass and abundance differed among fish guilds but not between weir and non-weir sites. Fishes from both site types selected for prey taxa predominately found at weirs. Differences between site types were not always captured by univariate metrics, but connecting fish prey to habitat suggests a reach-scale benefit for fishes through increased abundance of favored prey and enhanced prey diversity. Additionally, given the paucity of rocky substrata in the river as a whole, rock weirs enhance fish species richness by providing habitat for less common benthic species.

Drivers of nitrogen transfer in stream food webs across continents.

Studies of trophic-level material and energy transfers are central to ecology. The use of isotopic tracers has now made it possible to measure trophic transfer efficiencies of important nutrients and to better understand how these materials move through food webs. We analyzed data from thirteen 15 N-ammonium tracer addition experiments to quantify N transfer from basal resources to animals in headwater streams with varying physical, chemical, and biological features. N transfer efficiencies from primary uptake compartments (PUCs; heterotrophic microorganisms and primary producers) to primary consumers was lower (mean 11.5%, range <1% to 43%) than N transfer efficiencies from primary consumers to predators (mean 80%, range 5% to >100%). Total N transferred (as a rate) was greater in streams with open compared to closed canopies and overall N transfer efficiency generally followed a similar pattern, although was not statistically significant. We used principal component analysis to condense a suite of site characteristics into two environmental components. Total N uptake rates among trophic levels were best predicted by the component that was correlated with latitude, DIN:SRP, GPP:ER, and percent canopy cover. N transfer efficiency did not respond consistently to environmental variables. Our results suggest that canopy cover influences N movement through stream food webs because light availability and primary production facilitate N transfer to higher trophic levels.

Patch-Burn Grazing Effects on the Ecological Integrity of Tallgrass Prairie Streams.

Conversion to agriculture, habitat fragmentation, and the loss of native grazers have made tallgrass prairie one of the most endangered ecosystems. One management option for the remaining prairie parcels, patch-burn grazing (PBG), applies a controlled burn to a portion of the prairie to attract cattle, creating a mosaic of more- and less-grazed patches. Although beneficial to cattle and grassland birds, the potential impacts of PBG on streams have not been studied, and a holistic approach is needed to ensure against adverse effects. We used a Before-After-Control-Impact design to assess potential impacts of PBG with and without riparian protection on tallgrass prairie headwater streams. We sampled stream macroinvertebrates and benthic organic matter 2 yr before and 2 yr during PBG treatments on two grazed watersheds with riparian fencing (fenced), two unfenced grazed watersheds (unfenced), and two ungrazed (control) watersheds. Very fine benthic organic matter increased significantly (51%) in unfenced streams compared with controls ( < 0.007), and fine particulate organic matter (<1 mm and >250 µm) increased 3-fold in the unfenced streams compared with controls ( = 0.008). The contribution of fine inorganic sediments to total substrata increased 28% in unfenced streams during PBG, which was significantly different from controls ( = 0.03). Additionally, the abundance of Ephemeroptera, Plecoptera, and Trichoptera taxa decreased from 7635 to 687 individuals m in unfenced streams, which was significantly lower than in control streams ( = 0.008). Our results indicate that PBG adversely influences prairie streams through sediment inputs and reductions in sensitive invertebrate taxa, but riparian fencing can alleviate these impacts.

Home ventilation for patients with end-stage chronic obstructive pulmonary disease.

PURPOSE OF THE REVIEW: The number of patients with end-stage chronic obstructive pulmonary disease (COPD) treated with chronic non-invasive ventilation (NIV) has greatly increased. In this review, the authors summarize the evidence for nocturnal NIV and NIV during exercise. The authors discuss the multidisciplinary and advanced care of patients with end-stage COPD treated with NIV. RECENT FINDINGS: Nocturnal NIV improves gas exchange, health-related quality of life and survival in stable hypercapnic COPD patients. Improvements in care delivery have been achieved by relocating care from the hospital to home based; home initiation of chronic NIV is feasible, non-inferior regarding efficacy and cost-effective compared to in-hospital initiation. However, the effect of NIV on symptoms is variable, and applying optimal NIV for end-stage COPD is complex. While exercise-induced dyspnoea is a prominent complaint in end-stage COPD, nocturnal NIV will not change this. However, NIV applied solely during exercise might improve exercise tolerance and dyspnoea. While chronic NIV is often a long-standing treatment, patient expectations should be discussed early and be managed continuously during the treatment. Further, integration of advance care planning requires a multidisciplinary approach. SUMMARY: Although chronic NIV is an effective treatment in end-stage COPD with persistent hypercapnia, there are still important questions that need to be answered to improve care of these severely ill patients.

Palliation of Dyspnea With Mouthpiece Ventilation in Patients With Chronic Obstructive Pulmonary Disease: A Pilot Feasibility Study.

Background: Mouthpiece ventilation (MPV) reduces hypoventilation, but its efficacy in relieving dyspnea in patients with acute chronic obstructive pulmonary disease exacerbation (AECOPD) is unclear. Objective: To assess the feasibility of MPV in relieving dyspnea among patients with AECOPD. Methods: In this prospective single-arm pilot study, the change in dyspnea on numeric rating scale (NRS) after using MPV and side effects of the treatment were studied in 18 patients with AECOPD. Results: The median decrease in dyspnea was 1.5 (95% confidence interval = 0.0-2.5, p = 0.006) on NRS after the intervention lasting a median of 16.9 minutes. Of the patients, 61% found MPV beneficial. The use of MPV did not increase the sense of anxiety or pain. Conclusions: MPV is feasible and may relieve dyspnea in patients with AECOPD, but the intervention needs further evaluation. clinicaltrials.gov study number: NCT03025425.

Specialist Palliative Care Consultation for Patients with Nonmalignant Pulmonary Diseases: A Retrospective Study.

Background: Few patients with chronic nonmalignant pulmonary diseases receive specialist palliative care consultation, despite their high symptom burden in end of life. Objectives: To study palliative care decision making, survival, and hospital resource usage in patients with nonmalignant pulmonary diseases with or without a specialist palliative care consultation. Methods: A retrospective chart review of all patients with a chronic nonmalignant pulmonary disease and a palliative care decision (palliative goal of therapy), who were treated in Tampere University Hospital, Finland, between January 1, 2018 and December 31, 2020. Results: A total of 107 patients were included in the study, 62 (58%) had chronic obstructive pulmonary disease (COPD), and 43 (40%) interstitial lung disease (ILD). Median survival after palliative care decision was shorter in patients with ILD than in patients with COPD (59 vs. 213 days, p = 0.004). Involvement of a palliative care specialist in the decision making was not associated with the survival. Patients with COPD who received palliative care consultation visited less often emergency room (73% vs. 100%, p = 0.019) and spent fewer days in the hospital (7 vs. 18 days, p = 0.007) during the last year of life. When a palliative care specialist attended the decision making, the presence and opinions of the patients were recorded more often, and the patients were more frequently referred to a palliative care pathway. Conclusions: Specialist palliative care consultation seems to enable better end-of-life care and supports shared decision making for patients with nonmalignant pulmonary diseases. Therefore, palliative care consultations should be utilized in nonmalignant pulmonary diseases preferably before the last days of life.

Assessing Symptom Burden and Depression in Subjects With Chronic Respiratory Insufficiency.

Objectives: Patients with chronic respiratory insufficiency suffer from advanced disease, but their overall symptom burden is poorly described. We evaluated the symptoms and screening of depression in subjects with chronic respiratory insufficiency by using the Edmonton symptom assessment system (ESAS). Methods: In this retrospective study, 226 subjects with chronic respiratory insufficiency answered the ESAS questionnaire measuring symptoms on a scale from 0 (no symptoms) to 10 (worst possible symptom), and the depression scale (DEPS) questionnaire, in which the cut-off point for depressive symptoms is 9. Results: The most severe symptoms measured with ESAS (median [interquartile range]) were shortness of breath 4.0 (1.0-7.0), dry mouth 3.0 (1.0-7.0), tiredness 3.0 (1.0-6.0), and pain on movement 3.0 (0.0-6.0). Subjects with a chronic obstructive pulmonary disease as a cause for chronic respiratory insufficiency had significantly higher scores for shortness of breath, dry mouth, and loss of appetite compared to others. Subjects with DEPS ≥9 reported significantly higher symptom scores in all ESAS categories than subjects with DEPS <9. The area under the receiver operating characteristic curve for ESAS depression score predicting DEPS ≥9 was 0.840 (P < .001). If the ESAS depression score was 0, there was an 89% probability of the DEPS being <9, and if the ESAS depression score was ≥4, there was an 89% probability of the DEPS being ≥9. The relation between ESAS depression score and DEPS was independent of subjects' characteristics and other ESAS items. Conclusions: Subjects with chronic respiratory insufficiency suffer from a high symptom burden due to their advanced disease. The severity of symptoms increases with depression and 4 or more points in the depression question of ESAS should lead to a closer diagnostic evaluation of depression. Symptom-centered palliative care including psychosocial aspects should be early integrated into the treatment of respiratory insufficiency.

Simultaneous invasion decouples zebra mussels and water clarity.

Species invasions are a leading threat to ecosystems globally, but our understanding of interactions among multiple invasive species and their outcomes on ecosystem properties is undeveloped despite their significance to conservation and management. Here we studied a large lake in Minnesota, USA, that experienced a simultaneous surge in invasive zebra mussel and spiny water flea populations. A long-term (2000-2018) dataset offered a rare opportunity to assess whole-ecosystem shifts following the co-invasion. Within two years, the native crustacean zooplankton community declined abruptly in density and productivity (-93% and -91%, respectively). Summer phytoplankton abundance and water clarity remained stable across the time series, an unexpected outcome given the high density of zebra mussels in the lake. Observational data and modeling indicate that removal of native herbivorous zooplankton by the predatory spiny water flea reduced zooplankton grazing pressure enough to compensate new grazing losses due to zebra mussels, resulting in a zero net effect on phytoplankton abundance and water clarity despite a wholesale shift in secondary production from the pelagic to the benthic food web. This study reveals the extent of direct and indirect effects of two aquatic invaders on food-web processes that cancel shifts in water clarity, a highly valued ecosystem service.

Dyspnea on Exercise Is Associated with Overall Symptom Burden in Patients with Chronic Respiratory Insufficiency.

Background: Patients with chronic respiratory insufficiency suffer from many symptoms together with dyspnea. Objective: We evaluated the association of dyspnea on exercise with other symptoms in patients with chronic respiratory insufficiency due to chronic obstructive pulmonary disease or interstitial lung disease. Design: This retrospective study included 101 patients in Tampere University Hospital, Finland. Dyspnea on exercise was assessed with modified Medical Research Council (mMRC) dyspnea questionnaire, and other symptoms were assessed with Edmonton Symptom Assessment System (ESAS) and Depression Scale (DEPS). The study was approved by Regional Ethics Committee of Tampere University Hospital, Finland (approval code R15180/December 1, 2015). Results: Patients with mMRC 4 (most severe dyspnea) compared with those with mMRC 0-3 reported higher symptom scores on ESAS in shortness of breath (median 8.0 [IQR 6.0-9.0] vs. 4.0 [2.0-6.0], p < 0.001), dry mouth (7.0 [4.0-8.0] vs. 3.0 [1.0-6.0], p < 0.001), tiredness (6.0 [3.0-7.0] vs. 3.0 [1.0-5.0], p < 0.001), loss of appetite (3.0 [0.0-6.0] vs. 1.0 [0.0-3.0], p = 0.001), insomnia (3.0 [1.0-7.0] vs. 2.0 [0.0-3.0], p = 0.027), anxiety (3.0 [0.0-5.5] vs. 1.0 [0.0-3.0], p = 0.007), and nausea (0.0 [0.0-2.0] vs. 0.0 [0.0-0.3], p = 0.027). Patients with mMRC 4 were more likely to reach the DEPS threshold for depression than those scoring mMRC 0-3 (42.1% vs. 20.8%, p = 0.028). Conclusions: Patients with chronic respiratory insufficiency need comprehensive symptom screening with relevant treatment, as they suffer from broad symptom burden worsening with increased dyspnea on exercise.

Early presence of Bythotrephes cederströmii (Cladocera: Cercopagidae) in lake sediments in North America: evidence or artifact?

The spiny water flea (Bythotrephes cederströmii), a freshwater crustacean considered to be the world's best-studied invasive zooplankter, was first recorded in North America in the Laurentian Great Lakes during the 1980s. Its arrival is widely considered to be the result of ocean-going cargo ships that translocated contaminated ballast water from Eurasia to the Great Lakes during the 1970-1980s. The subsequent first discovery of the species in inland lakes is consistent with the hypothesis that propagules dispersed initially from established Great Lakes populations. Here we present evidence of exoskeletal remains, including mandibles, tail spines, and resting eggs, in 210Pb-dated lake sediment cores, which suggests that B. cederströmii was already resident in four inland North American lakes (two in Minnesota, USA; two in Ontario, Canada) by at least the early 1900s. Densities of exoskeletal remains were low and relatively steady from first appearance until about 1990, after which time they increased in all cores. The earliest evidence that we found was a mandible at 33-cm depth (pre-1650) in the sediments of Three Mile Lake, Ontario, Canada. These unexpected findings challenge the current paradigm of B. cederströmii invasion, renew uncertainty about the timing and sequence of its colonization of North American lakes, and potentially question our ability to detect invasive species with traditional sampling methods. We attempted to eliminate errors in the dated stratigraphies of the exoskeletal remains that might have been introduced either methodologically (e.g., core-wall smearing) or naturally (e.g., bioturbation). Nonetheless, given the very low numbers of subfossils encountered, questions remain about the possible artifactual nature of our observations and therefore we regard our results as 'preliminary findings' at this time.

Survival and end-of-life aspects among subjects on long-term noninvasive ventilation.

BACKGROUND: The need for noninvasive ventilation (NIV) is commonly considered a predictor of poor survival, but life expectancy may vary depending on the underlying disease. We studied the factors associated with decreased survival and end-of-life characteristics in an unselected population of subjects starting NIV. METHODS: We conducted a retrospective study including 205 subjects initiating NIV from 1/1/2012-31/12/2015 who were followed up until 31/12/2017. RESULTS: The median survival time was shorter in subjects needing help with activities of daily living than in independent subjects (hazard ratio (HR) for death 1.7, 95% CI 1.2-2.6, P = 0.008) and was also shorter in subjects on long-term oxygen therapy (LTOT) than in those not on LTOT (HR for death 2.8, 95% CI 1.9-4.3, P < 0.001). There was marked difference in survival according to the disease necessitating NIV, and subjects with amyotrophic lateral sclerosis or interstitial lung disease seemed to have the shortest survival. The two most common diseases resulting in the need for NIV were chronic obstructive pulmonary disease (COPD) and obesity hypoventilation syndrome (OHS). The median survival time was 4.4 years in COPD subjects, but the median survival time was not reached in subjects with OHS (HR for death COPD vs. OHS: 3.2, 95% CI 1.9-5.5, P < 0.001). Most of the deceased subjects (55.6%) died in the hospital, while only 20.0% died at home. The last hospitalization admission leading to death occurred through the emergency room in 44.4% of the subjects. CONCLUSIONS: Survival among subjects starting NIV in this real-life study varied greatly depending on the disease and degree of functional impairment. Subjects frequently died in the hospital after admission through the emergency department. A comprehensive treatment approach with timely advance care planning is therefore needed, especially for those needing help with activities of daily living and those with both NIV and LTOT.

Predictors of Impaired Survival in Subjects With Long-Term Oxygen Therapy.

BACKGROUND: The need for long-term oxygen therapy (LTOT) is usually a sign of advanced disease, which could trigger advance care planning. However, LTOT is used in patients with different characteristics and multiple diagnoses beyond COPD. We studied the factors associated with survival in an unselected sample of subjects who started LTOT. METHODS: We conducted a retrospective study that included 195 subjects for whom LTOT was initiated in Tampere University Hospital from January 1, 2012, to December 31, 2015, and followed up until December 31, 2017. RESULTS: The most frequent diseases that caused the need for LTOT were COPD and interstitial lung diseases. Most of the subjects (69%) died during the study period; the median survival time was 2.2 y. The subjects with interstitial lung disease as a primary disease for LTOT had a shorter survival time (median 0.9 y) compared with those with COPD (median 2.4 y, P < .001). Survival was shorter in the subjects ages >75 y (median 1.4 y) compared with those who were ages ≤75 y (median 2.8 y, P = .001) and also in those who required help with daily activities (median 1.2 y) compared with those who did not (median 3.3 y, P < .001). In multivariate analysis, a diagnosis of interstitial lung disease (hazard ratio 2.1, 95% CI 1.4-3.2), Charlson comorbidity index (hazard ratio 1.26, 95% Cl 1.11-1.43), and required help in activities of daily living (hazard ratio 2.1, 95% CI 1.4-3.1) were associated with impaired survival. CONCLUSIONS: The survival of the subjects who started LTOT varied greatly. The subjects with interstitial lung disease and those who required assistance with activities of daily living were at risk of dying in ∼1 y, which suggested that advance care planning should be directed especially to these patients.

Food webs: reconciling the structure and function of biodiversity.

The global biodiversity crisis concerns not only unprecedented loss of species within communities, but also related consequences for ecosystem function. Community ecology focuses on patterns of species richness and community composition, whereas ecosystem ecology focuses on fluxes of energy and materials. Food webs provide a quantitative framework to combine these approaches and unify the study of biodiversity and ecosystem function. We summarise the progression of food-web ecology and the challenges in using the food-web approach. We identify five areas of research where these advances can continue, and be applied to global challenges. Finally, we describe what data are needed in the next generation of food-web studies to reconcile the structure and function of biodiversity.