Aquatic Soundscape Recordings Reveal Diverse Vocalizations and Nocturnal Activity of an Endangered Frog.

AbstractAutonomous sensors provide opportunities to observe organisms across spatial and temporal scales that humans cannot directly observe. By processing large data streams from autonomous sensors with deep learning methods, researchers can make novel and important natural history discoveries. In this study, we combine automated acoustic monitoring with deep learning models to observe breeding-associated activity in the endangered Sierra Nevada yellow-legged frog (Rana sierrae), a behavior that current surveys do not measure. By deploying inexpensive hydrophones and developing a deep learning model to recognize breeding-associated vocalizations, we discover three undocumented R. sierrae vocalization types and find an unexpected temporal pattern of nocturnal breeding-associated vocal activity. This study exemplifies how the combination of autonomous sensor data and deep learning can shed new light on species' natural history, especially during times or in locations where human observation is limited or impossible.

Host density has limited effects on pathogen invasion, disease-induced declines and within-host infection dynamics across a landscape of disease.

1. Host density is hypothesized to be a major driver of variability in the responses and outcomes of wildlife populations following pathogen invasion. While the effects of host density on pathogen transmission have been extensively studied, these studies are dominated by theoretical analyses and small-scale experiments. This focus leads to an incomplete picture regarding how host density drives observed variability in disease outcomes in the field. 2. Here, we leveraged a dataset of hundreds of replicate amphibian populations that varied by orders of magnitude in host density. We used these data to test the effects of host density on three outcomes following the arrival of the amphibian-killing fungal pathogen Batrachochytrium dendrobatidis (Bd): the probability that Bd successfully invaded a host population and led to a pathogen outbreak, the magnitude of the host population-level decline following an outbreak and within-host infection dynamics that drive population-level outcomes in amphibian-pathogen systems. 3. Based on previous small-scale transmission experiments, we expected that populations with higher densities would be more likely to experience Bd outbreaks and would suffer larger proportional declines following outbreaks. To test these predictions, we developed and fitted a Hidden Markov Model that accounted for imperfectly observed disease outbreak states in the amphibian populations we surveyed. 4. Contrary to our predictions, we found minimal effects of host density on the probability of successful Bd invasion, the magnitude of population decline following Bd invasion and the dynamics of within-host infection intensity. Environmental conditions, such as summer temperature, winter severity and the presence of pathogen reservoirs, were more predictive of variability in disease outcomes. 5. Our results highlight the limitations of extrapolating findings from small-scale transmission experiments to observed disease trajectories in the field and provide strong evidence that variability in host density does not necessarily drive variability in host population responses following pathogen arrival. In an applied context, we show that feedbacks between host density and disease will not necessarily affect the success of reintroduction efforts in amphibian-Bd systems of conservation concern.

Effectiveness of antifungal treatments during chytridiomycosis epizootics in populations of an endangered frog.

The recently-emerged amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) has had an unprecedented impact on global amphibian populations, and highlights the urgent need to develop effective mitigation strategies. We conducted in-situ antifungal treatment experiments in wild populations of the endangered mountain yellow-legged frog during or immediately after Bd-caused mass die-off events. The objective of treatments was to reduce Bd infection intensity ("load") and in doing so alter frog-Bd dynamics and increase the probability of frog population persistence despite ongoing Bd infection. Experiments included treatment of early life stages (tadpoles and subadults) with the antifungal drug itraconazole, treatment of adults with itraconazole, and augmentation of the skin microbiome of subadults with Janthinobacterium lividum, a commensal bacterium with antifungal properties. All itraconazole treatments caused immediate reductions in Bd load, and produced longer-term effects that differed between life stages. In experiments focused on early life stages, Bd load was reduced in the 2 months immediately following treatment and was associated with increased survival of subadults. However, Bd load and frog survival returned to pre-treatment levels in less than 1 year, and treatment had no effect on population persistence. In adults, treatment reduced Bd load and increased frog survival over the entire 3-year post-treatment period, consistent with frogs having developed an effective adaptive immune response against Bd. Despite this protracted period of reduced impacts of Bd on adults, recruitment into the adult population was limited and the population eventually declined to near-extirpation. In the microbiome augmentation experiment, exposure of subadults to a solution of J. lividum increased concentrations of this potentially protective bacterium on frogs. However, concentrations declined to baseline levels within 1 month and did not have a protective effect against Bd infection. Collectively, these results indicate that our mitigation efforts were ineffective in causing long-term changes in frog-Bd dynamics and increasing population persistence, due largely to the inability of early life stages to mount an effective immune response against Bd. This results in repeated recruitment failure and a low probability of population persistence in the face of ongoing Bd infection.

Dyspnea in a 57-Year-Old Man With Recent Viral Illness.

CASE PRESENTATION: A 57-year-old man presented to the ED with a 1-month history of nonproductive cough and shortness of breath. The patient had been in his usual state of health until 2 months before presentation, when he experienced an episode of nonproductive cough and shortness of breath. He was diagnosed clinically with an upper respiratory tract infection; the symptoms resolved after 7 days with conservative therapy alone. One month later, the nonproductive cough and shortness of breath returned. He was treated with a 5-day course of oral azithromycin without any improvement in his symptoms. On presentation to the ED, he denied fever, chills, night sweats, chest pain, arthralgia, myalgia, or hemoptysis. His medical history was significant for hypertension, poorly controlled type 2 diabetes mellitus, and coronary artery bypass grafting. His medications included aspirin, metoprolol, metformin, and glipizide. He denied any history of tobacco, vaping, or recreational drug use. He worked as a cashier in a departmental store and has been doing so for most of his life.

A 67-Year-Old Woman With Progressive Dyspnea and Innumerous Pulmonary Nodules.

CASE PRESENTATION: A 67-year-old woman, who recently immigrated to the United States from Afghanistan, presented to the hospital after sustaining a mechanical fall. She had no significant medical history and was not on any medication routinely. She denied any fever, night sweats, weight loss, shortness of breath, or hemoptysis. The patient had no prior personal history or exposure to TB. Results of a previous purified protein derivative skin test upon immigration were negative.

Correlation of Respiratory Physiologic Parameters in Mechanically Ventilated Coronavirus Disease 2019 Patients.

Acute respiratory distress syndrome secondary to severe acute respiratory syndrome coronavirus-2 pneumonia or coronavirus disease 2019-related acute respiratory distress syndrome is the primary cause of mortality in coronavirus disease 2019. Some studies have described the concept of "high and low" elastance coronavirus disease 2019-related acute respiratory distress syndrome and proposed individualized management for the acute respiratory distress syndrome, deviating from low tidal volume ventilation. We report simultaneously measured respiratory parameters (static lung compliance, alveolar dead space ventilation, and shunt fraction) in 14 patients with advanced coronavirus disease 2019-related acute respiratory distress syndrome. The results were consistent with typical acute respiratory distress syndrome and did not support the concept of high-type coronavirus disease 2019-related acute respiratory distress syndrome and low-type coronavirus disease 2019-related acute respiratory distress syndrome.

Cannabinoid Oil Vaping-Associated Lung Injury and its Radiographic Appearance.

BACKGROUND: Lung injury associated with cannabinoid oil vaping is rapidly becoming a serious public health concern. We describe the clinical and radiographic presentations of 5 patients with lung injury associated with vaping cannabinoid oils seen at a single institution. RESULTS: Of the 5 patients with suspected vaping-associated lung injury seen at our institution, 4 required supplemental oxygen, and all these 4 were admitted to the hospital. Three patients required admission to the intensive care unit. None of the patients required mechanical ventilation. All patients demonstrated a consistent radiologic appearance of diffuse bilateral ground-glass lung opacities that spared the extreme periphery. Three patients underwent bronchoalveolar lavage, which revealed lipid-laden macrophages in 2 of them. All patients were successfully discharged from the hospital. Four received only supportive care, while the fifth required intravenous followed by oral corticosteroids. CONCLUSIONS: We report the clinical and radiographic presentation of 5 patients at our institution with cannabinoid oil vaping-associated lung injury. All patients displayed a consistent chest radiographic pattern of injury. Most responded to supportive care, although one required the addition of corticosteroids. Bronchoalveolar lavage results suggest that this injury may related to a toxic form of lipoid pneumonia.

Large scale variation in the rate of germ-line de novo mutation, base composition, divergence and diversity in humans.

It has long been suspected that the rate of mutation varies across the human genome at a large scale based on the divergence between humans and other species. However, it is now possible to directly investigate this question using the large number of de novo mutations (DNMs) that have been discovered in humans through the sequencing of trios. We investigate a number of questions pertaining to the distribution of mutations using more than 130,000 DNMs from three large datasets. We demonstrate that the amount and pattern of variation differs between datasets at the 1MB and 100KB scales probably as a consequence of differences in sequencing technology and processing. In particular, datasets show different patterns of correlation to genomic variables such as replication time. Never-the-less there are many commonalities between datasets, which likely represent true patterns. We show that there is variation in the mutation rate at the 100KB, 1MB and 10MB scale that cannot be explained by variation at smaller scales, however the level of this variation is modest at large scales-at the 1MB scale we infer that ~90% of regions have a mutation rate within 50% of the mean. Different types of mutation show similar levels of variation and appear to vary in concert which suggests the pattern of mutation is relatively constant across the genome. We demonstrate that variation in the mutation rate does not generate large-scale variation in GC-content, and hence that mutation bias does not maintain the isochore structure of the human genome. We find that genomic features explain less than 40% of the explainable variance in the rate of DNM. As expected the rate of divergence between species is correlated to the rate of DNM. However, the correlations are weaker than expected if all the variation in divergence was due to variation in the mutation rate. We provide evidence that this is due the effect of biased gene conversion on the probability that a mutation will become fixed. In contrast to divergence, we find that most of the variation in diversity can be explained by variation in the mutation rate. Finally, we show that the correlation between divergence and DNM density declines as increasingly divergent species are considered.

Are sites with multiple single nucleotide variants in cancer genomes a consequence of drivers, hypermutable sites or sequencing errors?

Across independent cancer genomes it has been observed that some sites have been recurrently hit by single nucleotide variants (SNVs). Such recurrently hit sites might be either (i) drivers of cancer that are postively selected during oncogenesis, (ii) due to mutation rate variation, or (iii) due to sequencing and assembly errors. We have investigated the cause of recurrently hit sites in a dataset of >3 million SNVs from 507 complete cancer genome sequences. We find evidence that many sites have been hit significantly more often than one would expect by chance, even taking into account the effect of the adjacent nucleotides on the rate of mutation. We find that the density of these recurrently hit sites is higher in non-coding than coding DNA and hence conclude that most of them are unlikely to be drivers. We also find that most of them are found in parts of the genome that are not uniquely mappable and hence are likely to be due to mapping errors. In support of the error hypothesis, we find that recurently hit sites are not randomly distributed across sequences from different laboratories. We fit a model to the data in which the rate of mutation is constant across sites but the rate of error varies. This model suggests that ∼4% of all SNVs are errors in this dataset, but that the rate of error varies by thousands-of-fold between sites.

Anesthesia residents' global (departmental) evaluation of faculty anesthesiologists' supervision can be less than their average evaluations of individual anesthesiologists.

BACKGROUND: Faculty anesthesiologists' supervision of anesthesiology residents is required for both postgraduate medical education and billing compliance. Previously, using the de Oliveira Filho et al. supervision question set, De Oliveira et al. found that residents who reported mean department-wide supervision scores <3.0 ("frequent") reported a significantly more frequent occurrence of mistakes with negative consequences to patients, as well as medication errors. In our department, residents provide daily evaluations of the supervision received by individual faculty. Using a survey study, we compared relationships between residents' daily supervision scores for individual faculty anesthesiologists and residents' supervision scores for the entire department (comprised these faculty). METHODS: We studied all anesthesiology residents in clinical years 1, 2, and 3 (i.e., neither in the "base year" nor in fellowship). There were daily evaluations of individual faculty supervision of operative anesthesia for 36 weeks. Residents clicked a hyperlink on the invitation e-mail taking them to a secure Web page to provide their global (departmental) assessment of faculty supervision. We calculated the ratio of each resident's global (departmental) faculty supervision score (i.e., mean among 9 questions × 1 evaluation) to the same resident's daily evaluations of individual faculty (i.e., mean among 9 questions × many evaluations). RESULTS: All 39 of 39 residents chose to participate. The mean departmental supervision score was significantly less (P < 0.0001) than the mean of individual faculty scores. The median ratio of scores was 86% (95% confidence interval, 83%-89%). Kendall's rank correlation between global and (mean) individual faculty scores was τb = 0.34 ± 0.11 (P = 0.0032). The ratios were uniformly distributed (P = 0.64) between the observed minimums and maximums; were not correlated with the mean value of individual faculty scores previously provided by each resident (P = 0.64); were not correlated with the number of individual faculty evaluations previously provided by each resident (P = 0.49); and did not differ among the first, second, or third year residents (P = 0.37). CONCLUSIONS: Residents' perceptions of overall (departmental) faculty supervision were less than overall averages of their perceptions of individual faculty supervision. This should be considered when interpreting national survey results (e.g., of patient safety), residency program evaluations, and individual faculty anesthesiologist performance.

Influence of provider type (nurse anesthetist or resident physician), staff assignments, and other covariates on daily evaluations of anesthesiologists' quality of supervision.

BACKGROUND: At many U.S. healthcare facilities, supervision of anesthesiology residents and/or Certified Registered Nurse Anesthetists (CRNAs) is a major daily responsibility of anesthesiologists. Our department implemented a daily process by which the supervision provided by each anesthesiologist working in operating rooms was evaluated by the anesthesiology resident(s) and CRNA(s) with whom they worked the previous day. METHODS: Requests for evaluation were sent daily via e-mail to each resident and CRNA after working in an operating room. Supervision scores were analyzed after 6 months, and aligned with the cases' American Society of Anesthesiologists Relative Value Guide units. RESULTS: (1) Mean monthly evaluation completion rates exceeded 85% (residents P = 0.0001, CRNAs P = 0.0005). (2) Pairwise by anesthesiologist, residents and CRNAs mean supervision scores were correlated (P < 0.0001), but residents assigned greater scores than did CRNAs (P < 0.0001). The pairwise differences between residents and CRNAs were heterogeneous among anesthesiologists (P < 0.0001). (3) Anesthesiologist supervision scores provided by residents were: (a) greater when a resident had more units of work that day with the rated anesthesiologist (P < 0.0001), and (b) less when the anesthesiologist had more units of work that same day with other providers (P < 0.0001). However, the relationships were unimportantly small, Kendall τb = +0.083 ± 0.014 (SE) and τb = -0.057 ± 0.014, respectively. The correlations were even less among the CRNAs, τb = -0.029 ± 0.013 and τb = -0.004 ± 0.012, respectively. (4) There also was unimportantly small association between a resident's or CRNA's mean score for an anesthesiologist and the number of days worked together (τb = -0.069 ± 0.023 and τb = +0.038 ± 0.020, respectively). CONCLUSIONS: Although the attributes that residents and CRNA perceive as constituting "supervision" significantly share commonalities, supervision scores should be analyzed separately for residents and CRNAs. Although mean supervision scores differ markedly among anesthesiologists, supervision scores are influenced negligibly by staff assignments (e.g., how busy the anesthesiologist is with other operating rooms).

Optimal temperature for malaria transmission is dramatically lower than previously predicted.

The ecology of mosquito vectors and malaria parasites affect the incidence, seasonal transmission and geographical range of malaria. Most malaria models to date assume constant or linear responses of mosquito and parasite life-history traits to temperature, predicting optimal transmission at 31 °C. These models are at odds with field observations of transmission dating back nearly a century. We build a model with more realistic ecological assumptions about the thermal physiology of insects. Our model, which includes empirically derived nonlinear thermal responses, predicts optimal malaria transmission at 25 °C (6 °C lower than previous models). Moreover, the model predicts that transmission decreases dramatically at temperatures > 28 °C, altering predictions about how climate change will affect malaria. A large data set on malaria transmission risk in Africa validates both the 25 °C optimum and the decline above 28 °C. Using these more accurate nonlinear thermal-response models will aid in understanding the effects of current and future temperature regimes on disease transmission.

Effects of low-dose fluticasone propionate/salmeterol combination therapy on exhaled nitric oxide and nitrite/nitrate in breath condensates from patients with mild persistent asthma.

OBJECTIVE: The long-acting ß2-agonist salmeterol in combination with the corticosteroid fluticasone propionate is used in clinical practice for the treatment of mild persistent asthma. Although the effect of fluticasone propionate alone in asthmatic patients is well documented, the effect of fluticasone propionate/salmeterol (FSC) combination therapy on airway inflammation and airway hyperresponsiveness (AHR) is not well characterized. Thus, we evaluated AHR, exhaled nitric oxide (FE(NO)), and nitrite and nitrate in exhaled breath condensates (EBCs) from mild persistent asthmatic patients treated with a low-dose FSC (100/50). METHODS: In this open label study, 18 mild persistent, steroid-naïve asthmatics (age, 22-62 years, forced expiratory volume in 1 s (FEV(1)) > 70% predicted, provocative dose resulting in 20% reduction (PD(20)) < 10 mg/mL) were treated with FSC 100/50 for 4 weeks. PD(20) to methacholine, FEV(1), FE(NO), and EBC nitrite and nitrate was measured before and after treatment. RESULTS: After 4 weeks of therapy with FSC 100/50, FE(NO) decreased from 74 ppb (SD = 37) to 34 ppb (SD = 15) (p < .001). FEV(1) (% predicted) increased from 89.4 (SD = 10.7) to 93.3 (SD = 9.5) (p < .01). The PD(20) for methacholine increased from 3.0 (±3.2) to 10.3 (±8.4) mg/mL (p < .01) in 3 of 18 patients reaching the maximum allowable dose (25 mg/mL). FE(NO) correlated with the log of the methacholine dose. There was no statistically significant change in EBC nitrite and nitrate before and after treatment. CONCLUSIONS: Treatment of mild persistent, steroid-naïve asthmatics with low-dose combination therapy is effective in rapidly reducing airway inflammation and AHR. Our results suggest different metabolic origins for nitrite, nitrate, and FE(NO) in this group of patients.

Use of the Case Western Reserve/Veterans Administration neuroprosthesis for exercise, standing and transfers by a paraplegic subject.

Functional electric stimulation (FES) is a technology that may allow patients with spinal cord injury (SCI) to transfer stand and walk. This paper reports upon the use of the Case Western Reserve Neuroprosthesis by a T6 ASIA B paraplegic subject. The subject was able to stand for two minutes and 50 seconds. He could walk 35 feet with a swing to gait. Measurement of energy consumption showed that metabolic demand was only 2.1 metabolic equivalent units. The factors that limited the use of the device that need to be improved to make the technology practical for household or community ambulation are speed (5.8 m/min) of ambulation and fatigue of the stimulated muscles.

A prospective, observational clinical trial of fever reduction to reduce systemic oxygen consumption in the setting of acute brain injury.

INTRODUCTION: Fever after acute brain injury appears to be a detrimental factor, associated with impaired neurological outcomes. This study assessed physiological changes in systemic oxygen consumption (VO2) during cutaneous cooling after severe brain injury. METHODS: This prospective, observational, clinical study evaluated ten, critically ill, brain-injured patients requiring mechanical ventilation with a core body temperature of greater or equal to 38 degrees C. Febrile patients failing to defervesce after acetaminophen underwent indirect calorimetry for a 1-hour baseline period followed by a 4 h cooling period. The Arctic Sun(R) Temperature Management System (Medivance) directed core temperature to a goal of 36 degrees C. RESULTS: The patients had a mean age of 32 years (95% CI 23, 40), Glasgow Coma Scale of 6 (95% CI 5,7), and APACHE 2 score of 19 (95% CI 15, 22), with 8 of 10 patients suffering traumatic brain injuries. The baseline 1-h core temperature was significantly reduced from 38.6 degrees +/- 0.9 to 36.3 degrees +/- 1.2 degrees C (P < 0.0001) over 4 h. Two cohorts were identified based upon the presence or absence of shivering. Within the non-shivering cohort, systemic VO2 was significantly reduced from 415 +/- 123 to 308 +/- 115 ml/min (-27 +/- 18%) (P < 0.05). In contrast, those with shivering showed no significant reduction in VO2, despite significantly decreasing core temperature. The overall percentage change of VCO2 correlated with VO2 (r (2) = 0.91). CONCLUSION: Fever reduction in acute brain injury appears to significantly reduce systemic VO2, but is highly dependent on shivering control.

Energy cost of the case Western reserve standing neuroprosthesis.

OBJECTIVE: To determine the oxygen consumption of a person with C7 American Spinal Injury Association (ASIA) grade B tetraplegia using the Case Western Reserve/Veterans Administration (CWRU/VA) standing neuroprosthesis. DESIGN: Measure the oxygen consumption and carbon dioxide production of a person with C7 ASIA grade B tetraplegia at rest, standing in the parallel bars with the CWRU/VA system on, ambulating in the parallel bars, and transferring from a wheelchair to a mat with the system on. SETTING: University medical center. PARTICIPANT: A 26-year-old man with C7 ASIA grade B tetraplegia. The subject was a recipient of the CWRU/VA standing neuroprosthesis. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Measurement of oxygen consumption and carbon dioxide production using a metabolic cart. RESULTS: Oxygen consumption of the subject was 1.22mL.kg(-1).min(-1) at rest. It was 4.7mL.kg(-1).min(-1) while standing in the parallel bars, 7.2mL.kg(-1).min(-1) while ambulating in the parallel bars, and 7.9mL.kg(-1).min(-1) when transferring from a wheelchair to a mat. CONCLUSIONS: Oxygen consumption of the subject when using the system is about 2 metabolic equivalent units, which is compatible with sustained use of the system for standing.

Detection of a malaria parasite (Plasmodium mexicanum) in ectoparasites (mites and ticks), and possible significance for transmission.

Two species of sandflies (Lutzomyia) are competent vectors of Plasmodium mexicanum, a malaria parasite of lizards. The very patchy distribution of sites with high P. mexicanum prevalence in the lizards, and often low or even nil sandfly density at such sites, provoked an evaluation of 2 common lizard ectoparasites, the tick Ixodes pacificus and the mite Geckobiella occidentalis, as potential passive vectors. Plasmodium sp.-specific polymerase chain primers were used to amplify a long segment of the mitochondrial cytochrome b gene that is unlikely to survive intact if the parasite cells are killed within a blood-feeding arthropod. The segment was strongly amplified from sandflies (the positive control for the method) from 1 to 96 hr postfeeding on an infected lizard. For ticks, the gene fragment was poorly amplified at 0 hr postfeed, and not amplified after 2 hr. In contrast, strong amplification of the parasite DNA was observed from mites from 0 to 20 hr postfeed, and weak amplification even at 96 hr.

Low-dose inhaled nitric oxide in patients with acute lung injury: a randomized controlled trial.

CONTEXT: Inhaled nitric oxide has been shown to improve oxygenation in acute lung injury. OBJECTIVE: To evaluate the clinical efficacy of low-dose (5-ppm) inhaled nitric oxide in patients with acute lung injury. DESIGN AND SETTING: Multicenter, randomized, placebo-controlled study, with blinding of patients, caregivers, data collectors, assessors of outcomes, and data analysts (triple blind), conducted in the intensive care units of 46 hospitals in the United States. Patients were enrolled between March 1996 and September 1999. PATIENTS: Patients (n = 385) with moderately severe acute lung injury, a modification of the American-European Consensus Conference definition of acute respiratory distress syndrome (ARDS) using a ratio of PaO2 to FiO2 of < or =250, were enrolled if the onset was within 72 hours of randomization, sepsis was not the cause of the lung injury, and the patient had no significant nonpulmonary organ system dysfunction at randomization. INTERVENTIONS: Patients were randomly assigned to placebo (nitrogen gas) or inhaled nitric oxide at 5 ppm until 28 days, discontinuation of assisted breathing, or death. MAIN OUTCOME MEASURES: The primary end point was days alive and off assisted breathing. Secondary outcomes included mortality, days alive and meeting oxygenation criteria for extubation, and days patients were alive following a successful unassisted ventilation test. RESULTS: An intent-to-treat analysis revealed that inhaled nitric oxide at 5 ppm did not increase the number of days patients were alive and off assisted breathing (mean [SD], 10.6 [9.8] days in the placebo group and 10.7 [9.7] days in the inhaled nitric oxide group; P =.97; difference, -0.1 day [95% confidence interval, -2.0 to 1.9 days]). This lack of effect on clinical outcomes was seen despite a statistically significant increase in PaO2 that resolved by 48 hours. Mortality was similar between groups (20% placebo vs 23% nitric oxide; P =.54). Days patients were alive following a successful 2-hour unassisted ventilation trial were a mean (SD) of 11.9 (9.9) for placebo and 11.4 (9.8) for nitric oxide patients (P =.54). Days alive and meeting criteria for extubation were also similar: 17.0 placebo vs 16.7 nitric oxide (P =.89). CONCLUSION: Inhaled nitric oxide at a dose of 5 ppm in patients with acute lung injury not due to sepsis and without evidence of nonpulmonary organ system dysfunction results in short-term oxygenation improvements but has no substantial impact on the duration of ventilatory support or mortality.

Physicians' perceptions of minimum time that should be saved to move a surgical case from one operating room to another: internet-based survey of the membership of the Association of Anesthesia Clinical Directors (AACD).

STUDY OBJECTIVE: Moving the last case of the day from one operating room (OR) to another OR can increase OR efficiency. However, there is a penalty cost for moving a case. The goal of the study was to measure perceptions of the minimum time that needs to be saved for it to be worthwhile to move a case from a late-running OR to another OR. DESIGN: Internet-based survey of the Association of Anesthesia Clinical Directors (AACD) and/or attendees at one of its courses. As subjects completed the computer-assisted survey, answers to test questions were checked immediately to ensure respondents understood the relevant concepts. MEASUREMENTS: Respondents were asked to complete the statement: "I would move the case if I would expect to save ____ hours of overutilized OR time." MAIN RESULTS: 234 E-mail invitations to complete the survey were transmitted. Of that number, 87 completed surveys were returned. Respondents were physicians, mostly from the United States. The 25th, 50th, and 75th percentiles of the penalty cost were 1.0 hour of overutilized OR time. The 95% confidence intervals were 0.5 to 1.0 hour for the 25th percentile, 1.0 to 1.0 hour for the 50th percentile, and 1.0 to 2.0 hours for the 75th percentile. There was no significant correlation between the penalty cost and the number of ORs at the respondent's facility, number of times the survey was submitted until it was completed correctly, or total number of errors in responses. CONCLUSIONS: Members of the AACD perceive the penalty cost for moving a case to be 1 hour.