230 research outputs found
Signal from the noise: model‐based interpretation of variable correspondence between active and passive samplers
Combining information from active and passive sampling of mobile animals is challenging because active‐sampling data are affected by limited detection of rare or sparse taxa, while passive‐sampling data reflect both density and movement. We propose that a model‐based analysis allows information to be combined between these methods to interpret variation in the relationship between active estimates of density and passive measurements of catch per unit effort to yield novel information on activity rates (distance/time). We illustrate where discrepancies arise between active and passive methods and demonstrate the model‐based approach with seasonal surveys of fish assemblages in the Florida Everglades, where data are derived from concurrent sampling with throw traps, an enclosure‐type sampler producing point estimates of density, and drift fences with unbaited minnow traps that measure catch per unit effort (CPUE). We compared incidence patterns generated by active and passive sampling, used hierarchical Bayesian modeling to quantify the detection ability of each method, characterized interspecific and seasonal variation in the relationship between density and passively measured CPUE, and used a predator encounter‐rate model to convert variable CPUE–density relationships into ecological information on activity rates. Activity rate information was used to compare interspecific responses to seasonal hydrology and to quantify spatial variation in non‐native fish activity. Drift fences had higher detection probabilities for rare and sparse species than throw traps, causing discrepancies in the estimated spatial distribution of non‐native species from passively measured CPUE and actively measured density. Detection probability of the passive sampler, but not the active sampler, varied seasonally with changes in water depth. The relationship between CPUE and density was sensitive to fluctuating depth, with most species not having a proportional relationship between CPUE and density until seasonal declines in depth. Activity rate estimates revealed interspecific differences in response to declining depths and identified locations and species with high rates of activity. We propose that variation in catchability from methods that passively measure CPUE can be sources of ecological information on activity. We also suggest that model‐based combining of data types could be a productive approach for analyzing correspondence of incidence and abundance patterns in other applications
Cost-Effectiveness of an Emergency Department Based Early Sepsis Resuscitation Protocol
Background
Guidelines recommend that sepsis be treated with an early resuscitation protocol, such as early goal directed therapy (EGDT). Our objective was to assess the cost-effectiveness of implementing EGDT as a routine protocol.
Design
Prospective before and after study.
Setting
Large urban hospital ED with >110,000 visits/year.
Patients
The target population was patients with consensus criteria for septic shock. We excluded those with age <18 yrs, no aggressive care desired, or need for immediate surgery.
Interventions
Clinical and cost data were prospectively collected on two groups: 1) patients from 1 yr before and 2) 2 yrs after implementing EGDT as standard-of-care. Before phase patients received nonprotocolized care at attending discretion. The primary outcomes were one year mortality, discounted life expectancy, and quality adjusted life years (QALYs). Using costs and QALYs, we constructed an incremental cost-effectiveness ratio and performed a net monetary benefit (NMB) analysis, producing the probability that the intervention was cost-effective given different values for the willingness to pay for a QALY.
Results
285 subjects, 79 in the before and 206 in the after phases, were enrolled. Treatment with EGDT was associated with an increased hospital cost of 5397 per QALY gained and the NMB analysis indicates a 98% probability (p = .038) that EGDT is cost-effective at a willingness to pay of $50,000 per QALY.
Conclusion
Implementation of EGDT in the ED care of severe sepsis patients is cost effective
The Aquatic Heteroptera (Hemiptera) of Marshes in the Florida Everglades
The Everglades is a large subtropical wetland that has been modified heavily by humans and now is undergoing restoration. Aquatic and semiaquatic Heteroptera (Hemiptera) in the infraorders Gerromorpha and Nepomorpha were collected in the Florida Everglades using standardized 1-m2throw-traps. Sampling efforts were conducted in marshes distributed from southern Everglades National Park, north throughout the Water Conservation Areas to Loxahatchee National Wildlife Refuge. In total, 12,833 individuals were identified representing 17 species in 13 genera and 8 families (Belostomatidae, Corixidae, Gerridae, Mesoveliidae, Naucoridae, Nepidae, Veliidae). The naucorid Pelocoris femoratus (Palisot de Beauvois) (Hemiptera: Naucoridae) was by far the most abundant species, whereas 2 other species, Belostoma lutarium (Stål) (Hemiptera: Belostomatidae) and Neogerris hesione Kirkaldy (Hemiptera: Gerridae), were widespread but less abundant. Two species, Abedus immaculatus (Say) (Hemiptera: Belostomatidae) and Pelocoris balius La Rivers (Hemiptera: Naucoridae) had localized distributions, whereas all other species were collected rarely. We discuss the abundance and distribution of species recorded, along with unique traits and the biology of the aquatic Heteroptera in the Everglades and implications for the restoration of the Everglades
Leukocyte Expression of Heme Oxygenase-1 [hmox1] Varies Inversely with Severity of Tricuspid Regurgitation in Acute Pulmonary Embolism.
Objective: Pulmonary embolism (PE) can cause intracardiac hemolysis and increased plasma hemoglobin and arginase-1, which can worsen pulmonary vasoconstriction. We test the hypothesis that patients with PE that causes tricuspid regurgitation (TR), indicative of higher pulmonary arterial pressures, have decreased leukocyte expression of hmox-1 compared with patients with PE and no TR and patients without PE. Design: Prospective, noninterventional study. Patients: Normotensive patients with suspected PE (n=87) who underwent CT pulmonary angiography and transthoracic Doppler-echocardiography. Measurements: Significant TR was defined as a jet velocity > 2.7m/s. Leukocyte expression of hmox-1, haptoglobin, haptoglobin related gene, the haptoglobin receptor, CD163 and cox-2 genes were assessed by quantitative rtPCR, and the hmox-1 promoter was examined for the −413 A→T SNP and GT repeat polymorphisms. Results: Of the 44 (50%) with PE+, 22 had TR+, and their mean pulmonary vascular occlusion (39±32%) did not differ significantly from patients who were TR− (28±26%, P=0.15). Patients with PE+ and TR+ had significantly lower expression of hmox-1 and haptoglobin genes than patients without PE+ and no TR. Expression of hmox-1 varied inversely with TR velocity (r2=0.45, P<0.001) for PE+ (n=22) but not patients without PE. Hmox-1 expression did not vary significantly with genotype. Cox-2 did not differ between groups and had no correlation with TR. Conclusions: Severity of TR varied inversely with hmox-1 expression, suggesting that hmox-1 expression affects pulmonary vascular reactivity after PE
The conference effect: National surgery meetings are associated with increased mortality at trauma centers without American College of Surgeons verification
BACKGROUND:
Thousands of physicians attend scientific conferences each year. While recent data indicate that variation in staffing during such meetings impacts survival of non-surgical patients, the association between treatment during conferences and outcomes of a surgical population remain unknown. The purpose of this study was to examine mortality resulting from traumatic injuries and the influence of hospital admission during national surgery meetings.
STUDY DESIGN:
Retrospective analysis of in-hospital mortality using data from the Trauma Quality Improvement Program (2010-2011). Identified patients admitted during four annual meetings and compared their mortality with that of patients admitted during non-conference periods. Analysis included 155 hospitals with 12,256 patients admitted on 42 conference days and 82,399 patients admitted on 270 non-conference days. Multivariate analysis performed separately for hospitals with different levels of trauma center verification by state and American College of Surgeons (ACS) criteria.
RESULTS:
Patient characteristics were similar between meeting and non-meeting dates. At ACS level I and level II trauma centers during conference versus non-conference dates, adjusted mortality was not significantly different. However, adjusted mortality increased significantly for patients admitted to trauma centers that lacked ACS trauma verification during conferences versus non-conference days (OR 1.2, p = 0.008), particularly for patients with penetrating injuries, whose mortality rose from 11.6% to 15.9% (p = 0.006).
CONCLUSIONS:
Trauma mortality increased during surgery conferences compared to non-conference dates for patients admitted to hospitals that lacked ACS trauma level verification. The mortality difference at those hospitals was greatest for patients who presented with penetrating injuries
Isolated heart model demonstrates evidence of contractile and diastolic dysfunction in right ventricles from rats with sugen/hypoxia‐induced pulmonary hypertension
Although extensively used for the study of left ventricular function, limited experience exists with the isolated heart model in the evaluation of right ventricular (RV) function. In particular, no published experience exists with this tool in sugen/hypoxia‐induced pulmonary hypertension (SuHx‐PH), a frequently used model of severe and progressive PH. We sought to characterize markers of RV contractile and diastolic function in SuHx‐PH and to establish their relationship with markers of maladaptive RV remodeling. Hearts were excised from anesthetized Sprague Dawley rats with or without SuHx‐PH and perfused via the aorta using a Langendorff preparation. We explored the Frank–Starling relationship of RV function (RV developed pressure, dP/dt
max, and dP/dt
min; all normalized to RV mass) by increasing RV end‐diastolic pressure (RVEDP) from 0 to 40 mmHg. Functional studies were complemented by quantification of RV pro‐apoptotic signaling (bcl2/bax), procontractile signaling (apelin), and stress response signaling (p38MAPK activation). Pearson's correlation analysis was performed for functional and biochemical parameters. SuHx‐RVs exhibited severe RV dysfunction with marked hypertrophy and decreased echocardiographic cardiac output. For any given RVEDP, SuHx‐RVs demonstrated less developed pressure and lower dP/dt
max, as well as less pronounced dP/dt
min, suggestive of decreased contractile and diastolic function. SuHx‐RVs exhibited decreased bcl2/bax ratios, apelin expression, and p38MAPK activation. Bcl2/bax and apelin RNA abundance correlated positively with RV developed pressure and dP/dt
max and negatively with dP/dt
min. p38MAPK activation correlated positively with RV developed pressure. We conclude that SuHx‐RVs exhibit severe contractile and diastolic dysfunction. Increased pro‐apoptotic signaling and attenuated procontractile and stress response signaling may contribute to these functional alterations
Controlled clinical trial of canine therapy versus usual care to reduce patient anxiety in the emergency department
Objective Test if therapy dogs reduce anxiety in emergency department (ED) patients. Methods In this controlled clinical trial (NCT03471429), medically stable, adult patients were approached if the physician believed that the patient had “moderate or greater anxiety.” Patients were allocated on a 1:1 ratio to either 15 min exposure to a certified therapy dog and handler (dog), or usual care (control). Patient reported anxiety, pain and depression were assessed using a 0–10 scale (10 = worst). Primary outcome was change in anxiety from baseline (T0) to 30 min and 90 min after exposure to dog or control (T1 and T2 respectively); secondary outcomes were pain, depression and frequency of pain medication. Results Among 93 patients willing to participate in research, 7 had aversions to dogs, leaving 86 (92%) were willing to see a dog six others met exclusion criteria, leaving 40 patients allocated to each group (dog or control). Median and mean baseline anxiety, pain and depression scores were similar between groups. With dog exposure, median anxiety decreased significantly from T0 to T1: 6 (IQR 4–9.75) to T1: 2 (0–6) compared with 6 (4–8) to 6 (2.5–8) in controls (P<0.001, for T1, Mann-Whitney U and unpaired t-test). Dog exposure was associated with significantly lower anxiety at T2 and a significant overall treatment effect on two-way repeated measures ANOVA for anxiety, pain and depression. After exposure, 1/40 in the dog group needed pain medication, versus 7/40 in controls (P = 0.056, Fisher’s exact test). Conclusions Exposure to therapy dogs plus handlers significantly reduced anxiety in ED patients
Pulmonary Dysfunction in Patients with Femoral Shaft Fracture Treated with Intramedullary Nailing
Background: This study was undertaken to determine whether alveolar dead space increases during intramedullary nailing of femoral shaft fractures and whether alveolar dead space predicts postoperative pulmonary dysfunction in patients undergoing intramedullary nailing of a femoral shaft fracture.
Methods: All patients with a femoral shaft fracture were prospectively enrolled in the study unless there was evidence of acute myocardial infarction, shock, or heart failure. Arterial blood gases were measured at three consecutive time-periods after induction of general anesthesia: before intramedullary nailing and ten and thirty minutes after intramedullary nailing. The end-tidal carbon-dioxide level, minute ventilation, positive end‐expiratory pressure, and percent of inspired and expired inhalation agent were recorded simultaneously with the blood-gas measurement. Postoperatively, all subjects were monitored for evidence of pulmonary dysfunction, defined as the need for mechanical ventilation or supplemental oxygen (at a fraction of inspired oxygen of >40%) in the presence of clinical signs of a respiratory rate of >20 breaths/min or the use of accessory muscles of respiration.
Results: Seventy‐four patients with a total of eighty femoral shaft fractures completed the study. Fifty fractures (62.5%) underwent nailing after reaming, and thirty fractures (37.5%) underwent nailing with minimal or no reaming. The mean alveolar dead-space measurements before canal opening and at ten and thirty minutes after canal opening were 14.5%, 15.8%, and 15.2% in the total series of seventy‐four patients (general linear model, p = 0.2) and 20.5%, 22.7%, and 24.2% in the twenty patients with postoperative pulmonary dysfunction (general linear model, p = 0.05). Of the twenty‐one patients with an alveolar dead-space measurement of >20% thirty minutes after nailing, sixteen had postoperative pulmonary dysfunction. According to univariate and multivariate analysis, the alveolar dead-space measurement was strongly associated with postoperative pulmonary dysfunction.
Conclusions: According to our data, intramedullary nailing of femoral shaft fractures did not significantly increase alveolar dead space, and the amount of alveolar dead space can predict which patients will have pulmonary dysfunction postoperatively
Randomized trial of inhaled nitric oxide to treat acute pulmonary embolism: The iNOPE trial
BACKGROUND:
The study hypothesis is that administration of inhaled nitric oxide (NO) plus oxygen to subjects with submassive pulmonary embolism (PE) will improve right ventricular (RV) systolic function and reduce RV strain and necrosis, while improving patient dyspnea, more than treatment with oxygen alone.
METHODS:
This article describes the rationale and protocol for a registered (NCT01939301), nearly completed phase II, 3-center, randomized, double-blind, controlled trial. Eligible patients have pulmonary imaging-proven acute PE. Subjects must be normotensive, and have RV dysfunction on echocardiography or elevated troponin or brain natriuretic peptide and no fibrinolytics. Subjects receive NO plus oxygen or placebo for 24 hours (±3 hours) with blood sampling before and after treatment, and mandatory echocardiography and high-sensitivity troponin posttreatment to assess the composite primary end point. The sample size of N=78 was predicated on 30% more NO-treated patients having a normal high-sensitivity troponin (<14 pg/mL) and a normal RV on echocardiography at 24 hours with α=.05 and β=.20. Safety was ensured by continuous spectrophotometric monitoring of percentage of methemoglobinemia and a predefined protocol to respond to emergent changes in condition. Blinding was ensured by identical tanks, software, and physical shielding of the device display and query of the clinical care team to assess blinding efficacy.
RESULTS:
We have enrolled 78 patients over a 31-month period. No patient has been withdrawn as a result of a safety concern, and no patient has had a serious adverse event related to NO.
CONCLUSIONS:
We present methods and a protocol for the first double-blinded, randomized trial of inhaled NO to treat PE
Independent evaluation of a simple clinical prediction rule to identify right ventricular dysfunction in patients with shortness of breath
BACKGROUND:
Many patients have unexplained persistent dyspnea after negative computed tomographic pulmonary angiography (CTPA). We hypothesized that many of these patients have isolated right ventricular (RV) dysfunction from treatable causes. We previously derived a clinical decision rule (CDR) for predicting RV dysfunction consisting of persistent dyspnea and normal CTPA, finding that 53% of CDR-positive patients had isolated RV dysfunction. Our goal is to validate this previously derived CDR by measuring the prevalence of RV dysfunction and outcomes in dyspneic emergency department patients.
METHODS:
A secondary analysis of a prospective observational multicenter study that enrolled patients presenting with suspected PE was performed. We included patients with persistent dyspnea, a nonsignificant CTPA, and formal echo performed. Right ventricular dysfunction was defined as RV hypokinesis and/or dilation with or without moderate to severe tricuspid regurgitation.
RESULTS:
A total of 7940 patients were enrolled. Two thousand six hundred sixteen patients were analyzed after excluding patients without persistent dyspnea and those with a significant finding on CTPA. One hundred ninety eight patients had echocardiography performed as standard care. Of those, 19% (95% confidence interval [CI], 14%-25%) and 33% (95% CI, 25%-42%) exhibited RV dysfunction and isolated RV dysfunction, respectively. Patients with isolated RV dysfunction or overload were more likely than those without RV dysfunction to have a return visit to the emergency department within 45 days for the same complaint (39% vs 18%; 95% CI of the difference, 4%-38%).
CONCLUSION:
This simple clinical prediction rule predicted a 33% prevalence of isolated RV dysfunction or overload. Patients with isolated RV dysfunction had higher recidivism rates and a trend toward worse outcomes
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