Ventilation Events Research Articles

Characterizing ventilation events in an anoxic coastal basin: Observed dynamics and the role of climatic drivers

AbstractRestricted horizontal exchange and vertical stratification restrict ventilation of bottom waters in many coastal systems, leading to stagnant basin water conditions. Dense inflows from oceanic sources can lead to dramatic changes in basin‐scale properties over very short timescales. Here, we used a semi‐enclosed coastal basin with deep‐anoxia (Lough Furnace) as a test bed, in order to discern estuary‐ocean exchange dynamics that lead to irregular and ephemeral deep‐water ventilations. Measured densities and current profiler‐based estimates of volume fluxes were used to compute typical renewal times of individual water masses in the stratified inner basin. Renewal timescales were primarily determined by freshwater flux and the spring‐neap tidal cycle. The deployment period culminated with observations of a ventilation of the basin water which had been stagnant for over 2.5 yr. Entrainment of ambient resident water doubled the volume of the dense plume and diluted its oxygen content. Following ventilation, the volumetric extent of anoxia expanded by 20% within several months, owing to uplifting of old basin water and oxygen consumption in the new basin water. Founded on these observations, a predictive model was constructed relying only on freshwater, atmospheric pressure, and wind data and successfully recreated ventilation events over the past decade. Hindcasting the model back multiple decades implied contrasting periods of higher and lower frequency variability in ventilation occurrence. This model offers a diagnostic tool for assessing how climatic change may influence the oxygen climate in systems that experience contrasting regimes of suboxia and ventilation.

Prognostic factors influencing prolonged ventilation after open mitral valve surgery

Objective: To determine prognostic factors influencing prolonged ventilation after surgery in our hospital. Method: Seventy-five patients fulfilled inclusion criteria were included in this retrospective cross-sectional study. Prognostic factors analyzed were age, chronic pulmonary disease, heart failure (NYHA class function), left ventricular (LV) dysfunction (based on ejection fraction), recent myocardial infarction, pulmonary hypertension (PH), duration of cardiopulmonary bypass (CPB), ischemic time and aorta clamp time, which were analyzed in relation to prolonged ventilation after open mitral valve surgery. Results: Subjects were 75 patients aged between 19 and 62 years old (mean 39.76, SD 11.44) whom underwent open mitral valve repair or replacement surgery. Twenty-three patients (30.67%) had prolonged ventilation (≥24 hours) after surgery. Bivariate analysis showed there were no significant correlation between age, heart failure, PH and LV dysfunction. There are different with statistically significance between groups (p<0.05). Conclusions: In this study, almost one-third of patients had prolonged ventilation after surgery. Factors influencing this morbidity were the duration of ischemic time, aorta clamp time and CPB. Age, heart failure, LV dysfunction and PH were not statistically related to the prolonged ventilation event.

Impact of deep oropharyngeal suctioning on microaspiration, ventilator events, and clinical outcomes: A randomized clinical trial.

To evaluate a deep oropharyngeal suction intervention (NO-ASPIRATE) in intubated patients on microaspiration, ventilator-associated events and clinical outcomes. Prospective, two-group, single-blind, randomized clinical trial. The study was conducted between 2014 - 2017 in 513 participants enroled within 24hr of intubation and randomized into NO-ASPIRATE or usual care groups. Standard oral care was provided to all participants every 4hr and deep oropharyngeal suctioning was added to the NO-ASPIRATE group. Oral and tracheal specimens were obtained to quantify α-amylase as an aspiration biomarker. Data were analysed for 410 study completers enrolled at least 36hr: NO-ASPIRATE (N=206) and usual care (N=204). Percent of tracheal specimens positive for α-amylase, mean tracheal α-amylase levels over time and ventilator-associated events were not different between groups. The NO-ASPIRATE group had a shorter hospital length of stay and a subgroup with moderate aspiration at baseline had significantly lower α-amylase levels across time. Hospital length of stay was shorter in the NO-ASPIRATE group and a subgroup of intervention participants had lower α-amylase across time. Delivery of standardized oral care to all participants may have been an intervention itself and possibly associated with the lack of significant findings for most outcomes. This trial compared usual care to oral care with a deep suctioning intervention on microaspiration and ventilator-associated events, as this has not been systematically studied. Further research on the usefulness of α-amylase as an aspiration biomarker and the role of oral suctioning, especially for certain populations, is indicated. ClinicalTrials.gov: NCT02284178.

Evaluation of the CleanSweep™ Closed Suction System on Length of Mechanical Ventilation and Ventilator-Associated Events

Evaluation of the CleanSweep™ Closed Suction System on Length of Mechanical Ventilation and Ventilator-Associated Events

Eastern Mediterranean Deep Water Formation During Sapropel S1: A Reconstruction Using Geochemical Records Along a Bathymetric Transect in the Adriatic Outflow Region

AbstractEastern Mediterranean thermohaline circulation is directly influenced by middle‐ and low‐latitude climate systems. The dramatic paleoclimate changes during the last African Humid Period (~10–6 ka BP) were captured in Mediterranean sediments as the distinctly organic‐rich unit sapropel S1. Here, deepwater formation variability during S1 deposition is reconstructed. We use geochemical records of three cores along a bathymetric transect (775‐, 1,359‐, and 1,908‐m water depths), at the transition between the Adriatic DW‐ formation area and the Eastern Mediterranean. In all three cores, sedimentation rates are distinctly higher during S1, corresponding with enhanced runoff emanating from the Adriatic hinterland. Hence, major runoff did not only come from southern but also from northern borderlands in this period. During sapropel formation, enhanced levels of primary productivity occurred in the surface waters and oxygen‐depleted conditions in the bottom waters for all sites. Conditions for sediment and bottom‐water below ~1.4 km water depth were sulfidic throughout S1, but for intermediate depth (775 m) were anoxic only during the first part (S1a). Bottom‐water oxygenation interrupted S1 formation at water depths down to ~1.4 km, during two brief episodes, at 8.2 and 7.4 cal. ka BP. From the 7.4 cal. ka BP ventilation onward, the transition to more oxygenated bottom‐water conditions was more progressive for the intermediate water depth site (775 m) than for the deeper sites. Conditions remained fully oxic for all water depths following the S1‐MarkerBed ventilation event. Possibly, the onset of continuously oxic conditions started slightly earlier at intermediate depth (775 m; 6.6 ± 0.3 cal. ka BP) than at greater depths (1,359 m, 1,908 m; 6.0 ± 0.3 cal. ka BP).

Biogeochemical Cycling of Dissolved Zinc in the Western Arctic (Arctic GEOTRACES GN01)

AbstractThe biogeochemical cycling of dissolved zinc (dZn) was investigated in the Western Arctic along the U.S. GEOTRACES GN01 section. Vertical profiles of dZn in the Arctic are strikingly different than the classic “nutrient‐type” profile commonly seen in the Atlantic and Pacific Oceans, instead exhibiting higher surface concentrations (~1.1 nmol/kg), a shallow subsurface absolute maximum (~4–6 nmol/kg) at 200 m coincident with a macronutrient maximum, and low deep water concentrations (~1.3 nmol/kg) that are homogeneous (sp.) with depth. In contrast to other ocean basins, typical inputs such as rivers, atmospheric inputs, and especially deep remineralization are insignificant in the Arctic. Instead, we demonstrate that dZn distributions in the Arctic are controlled primarily by (1) shelf fluxes following the sediment remineralization of high Zn:C and Zn:Si cells and the seaward advection of those fluxes and (2) mixing of dZn from source waters such as the Atlantic and Pacific Oceans rather than vertical biological regeneration of dZn. This results in both the unique profile shapes and the largely decoupled relationship between dZn and Si found in the Arctic. We found a weak dZn:Si regression in the full water column (0.077 nmol/μmol, r2 = 0.58) that is higher than the global slope (0.059 nmol/μmol, r2 = 0.94) because of the shelf‐derived halocline dZn enrichments. We hypothesize that the decoupling of Zn:Si in Western Arctic deep waters results primarily from a past ventilation event with unique preformed Zn:Si stoichiometries.

Nursing oral suction intervention to reduce aspiration and ventilator events (NO-ASPIRATE): A randomized clinical trial.

The primary aim of this study is to compare an oropharyngeal suction intervention versus usual care on microaspiration in intubated patients. Secondary aims are to evaluate the intervention on ventilator-associated condition rates, time to occurrence and compare tracheal-oral α-amylase ratios between groups. Prospective randomized clinical trial. The study received funding from the National Institutes of Health in February 2014 and Institutional Review Board approval in July 2013. Over 4years, a convenience sample of 600 orally intubated, ventilated adult patients will be enrolled within 24hr of intubation. The target sample is 400 participants randomized to the two groups. The intervention involves enhanced suctioning of the mouth and oropharynx every 4hr, while the usual care group receives a sham suctioning. The research team will deliver usual oral care to all patients every 4hr and collect oral and tracheal specimens every 12hr, to quantify α-amylase levels to detect aspiration of oral secretions. Study completers must be enrolled at least 36hr (baseline and three paired samples). Outcomes include α-amylase levels, percent of positive specimens, ventilator-associated conditions, length of stay, ventilator hours, and discharge disposition. Enrolment has closed, and data analysis has begun. Subgroup analyses emerged, contributing to future research knowledge. Standardized interventions have reduced but do not address all risk factors associated with ventilator-associated conditions. This study provides the potential to reduce microaspiration and associated sequelae in critically ill, intubated patients.

Results from a Quality Improvement Project to Decrease Infection-Related Ventilator Events in Trauma Patients at a Community Teaching Hospital

Ventilator-associated pneumonia (VAP) is linked to increased morbidity and mortality and clinical protocols (VAP bundles) have evolved to minimize VAP. In 2009, a quality improvement project was implemented at our institution to decrease VAP rates in adult trauma patients. A VAP prevention committee was developed, and formal evidence-based education for the nursing and physician staff was introduced. During the study period (2009-2016), 2380 patients required ICU admission to our Level II trauma center. The mean Injury Severity Score was 33 + 12, and there were 17 per cent penetrating and 83 per cent blunt injuries. The early compliance (2010) with the VAP bundle was 65 per cent. Within one year of the implementation of VAP prevention, the compliance increased to >90 per cent. Compliance has been carefully trended and has remained at 100 per cent. All of the aforementioned interventions have resulted in a sustained dramatic decline in VAP, from 12 per cent in 2009 to 0 per cent in 2016. Ongoing education and ICU policy development has become the mainstay of our trauma ICU program. The introduction of evidence-based care education imparted a culture of excellence resulting in favorable outcomes in high-risk trauma patients related to VAP prevention. Ongoing monitoring and education is required to sustain these promising outcomes.

Minute ventilation assessment in the PACU is useful to predict postoperative respiratory depression following discharge to the floor: A prospective cohort study

Study Objective.Reliably identifying patients at risk for postoperative respiratory depression (RD) remains an unmet need. We hypothesized that defined low minute ventilation events (LMVe) near the end of the post-anesthesia care unit (PACU) stay identifies patients at RD risk on the general hospital floor (GHF). DesignProspective observational study. SettingTertiary care, urban academic medical center. PACU and GHF during the first postoperative night. PatientsOne hundred-and-nineteen adult, ASA I – III patients undergoing elective surgery under general anesthesia completed the study. InterventionsData collection from a non-invasive respiratory volume monitor and the patients' medical record perioperatively through the first postoperative night. MeasurementsMinute ventilation (MV), tidal volume (TV) and respiratory rate (RR) were measured continuously in the PACU and on the GHF. MV was counted as the percent of individual predicted MV (MVPRED), and RD was defined as ≥1 LMVe/h on the GHF. Based on the number of LMVes within 30 min before PACU discharge, patients were grouped into A, ‘Not-At-Risk’: 0 LMVe and B, ‘At-Risk’: ≥1 LMVes. Unpaired t-test, Mann-Whitney U test, ANOVA, Kruskal-Wallis test, Fisher's exact test, sensitivity and specificity and ROC curve analyses were applied as appropriate. Main resultsOne hundred-and-six (89%) and 13 (11%) patients met Group A and B criteria respectively. The latter had more LMVe/h on the GHF (median 0.81 vs 0, p ≤ 0.001), and their MVPRED was significantly less. Following opioid administration, the LMVe likelihood was 43% in Group B and 5.6% in Group A. As a predictor for RD on the GHF, the number of LMVe in the last 30 min of PACU, had positive and negative predictive values of 61.5% and 90.6%, respectively. ConclusionMinute ventilation assessment in the PACU as described in this study can be useful to identify patients at risk for postoperative respiratory depression.

The Optical Signature of a Bottom Boundary Layer Ventilation Event in the Northern Gulf of Mexico's Hypoxic Zone

AbstractOceanographic observations in the northern Gulf of Mexico captured an unusual combination of atmospheric forcing and shelf frontal dynamics that brought about the surface ventilation of sediment‐laden bottom waters. Colorimetric analysis of in situ optical data indicates a specific turquoise‐white color signature for turbid and low‐oxygen bottom waters that match a coincident shelf‐wide feature detected in Moderate Resolution Imaging Spectroradiometer satellite true color images. The physical processes leading to this ventilation event are simulated using the Coupled Ocean Atmosphere Mesoscale Prediction System, which includes an integrated surface wave model. The combined model‐data analysis suggests that low‐oxygen, bottom water ventilation may occur episodically during boreal spring and summer in the northern Gulf of Mexico following the passage of high‐energy atmospheric systems, and these events may be identified in the historical satellite record based on the unique bottom water optical characteristics.

The unprecedented 2014 Legionnaires' disease outbreak in Portugal: atmospheric driving mechanisms.

A large outbreak of Legionnaires' disease occurred in November 2014 nearby Lisbon, Portugal. This epidemic infected 377 individuals by the Legionella pneumophila bacteria, resulting in 14 deaths. The primary source of transmission was contaminated aerosolized water which, when inhaled, lead to atypical pneumonia. The unseasonably warm temperatures during October 2014 may have played a role in the proliferation of Legionella species in cooling tower systems. The episode was further exacerbated by high relative humidity and a thermal inversion which limited the bacterial dispersion. Here, we analyze if the Legionella outbreak event occurred during a situation of extreme potential recirculation and/or stagnation characteristics. In order to achieve this goal, the Allwine and Whiteman approach was applied for a hindcast simulation covering the affected area during a near 20-year long period (1989-2007) and then for an independent period covering the 2014 event (15 October to 13 November 2014). The results regarding the average daily critical transport indices for the 1989-2007 period clearly indicate that the airshed is prone to stagnation as these events have a dominant presence through most of the study period (42%), relatively to the occurrence of recirculation (18%) and ventilation (17%) events. However, the year of 2014 represents an exceptional year when compared to the 1989-2007 period, with 53 and 33% of the days being classified as under stagnation and recirculation conditions, respectively.

Improving patient safety during procedural sedation via respiratory volume monitoring: A randomized controlled trial

Study objectiveAssess the utility of a respiratory volume monitor (RVM) to reduce the incidence of low minute ventilation events in procedural sedation. DesignRandomized control trial SettingEndoscopy suite PatientsSeventy-three total patients (ASA Physical Status 1–3) undergoing upper endoscopies were analyzed. InterventionPatients were randomized into two groups using a computer generated randomization table: Control (n=41): anesthesia provider was unable to see the screen of the RVM; RVM (n=32): anesthesia provider had access to RVM data to assist with management of the case. MeasurementsMinute ventilation (MV), tidal volume, and respiratory rate were continuously recorded by the RVM. MV is presented as percent of Baseline MV (MVBaseline), defined during a 30s period of quiet breathing prior to sedation. We defined Low MV as MV<40% MVBaseline, and calculated the percentage of procedure spent with Low MV. Patients in the RVM group were stratified based on whether the anesthesiologist rated the RVM as “not useful”, “somewhat useful”, or “very useful” during the case. Main resultsControl patients experienced twice as much Low MV compared to RVM patients (15.3±2.8% vs. 7.1±1.4%, P=0.020). The “not useful” (13.7±3.8%) group showed no improvement over the Control group (p=0.81). However, both the “very useful” (4.7±1.4%) and “somewhat useful” (4.9±1.7%) groups showed significant improvement over the “not useful” group (p<0.05). ConclusionsPatients in the Control group spent more than double the amount of time with Low MV compared to the RVM group. This difference became more pronounced when the anesthesiologist found the RVM useful for managing care, lending credibility to the usage of minute ventilation monitoring in procedural sedation.

Deep ventilation event during fall and winter 2015 in the Puyuhuapi Fjord (44.6 S)

The Puyuhuapi fjord has previously been reported as one of the hypoxic fjords in Patagonia (dissolved oxygen -DO below 2 mL L -1 ). Hydrographic sampling between 1995-2015 confirmed hypoxia below 100 m depth, down to the bottom (250 m). A line of sensors at an oceanographic mooring in Puyuhuapi were deployed to continuously record the temporal-vertical behaviour of water column temperature and salinity from the surface down to ~ 120 m, from February to July 2015. A multi-Parameter water quality sonde was deployed at the bottom of the line, with a DO optical sensor. From February to mid-May, hypoxia was sustained (1.4-1.6 mL L -1 ). However, from May until the end of June, DO values increased (2.8 mL L -1 ), exceeding the hypoxia threshold. This was the first event of deep ventilation reported in a Patagonia fjord. During this time period, deep water temperatures increased by ~ 1.3 °C, coinciding with the decreased in salinity from 33.6 to 32.8. The main cause of this event was attributed to the arrival of a new volume of mixed oceanic water into the fjord, transported by Modified Subantartic Water, with warm temperatures and slightly higher DO values, given its origin in the surface layer of the outer region of the Patagonian fjords and channels.

Major Bottom Water Ventilation Events Do Not Significantly Reduce Basin-Wide Benthic N and P Release in the Eastern Gotland Basin (Baltic Sea)

Redox-sensitive mobilization of nutrients from sediments strongly affects the eutrophic state of the central Baltic Sea; a region associated with the spread of hypoxia and almost permanently anoxic and sulfidic conditions in the deeper basins. Ventilation of these basins depends on renewal by inflow of water enriched in oxygen (O2) from the North Sea, occurring roughly once per decade. Benthic fluxes and water column distributions of dissolved inorganic nitrogen species, phosphate (PO43-), dissolved inorganic carbon (DIC), sulfide (HS-) and total oxygen uptake (TOU) were measured along a depth gradient in the Eastern Gotland Basin (EGB). Campaigns were conducted during euxinic conditions of the deep basin in Aug./Sept. 2013 and after two inflow events in July/Aug. 2015 and March 2016 when O2 concentrations in deep waters reached 60 µM. The intrusion of O2-rich North Sea water into the EGB led to an approximate 33 % and 10 % reduction of the seabed PO43- and ammonium (NH4+) release from deep basin sediments. Post-inflow, the deep basin sediment was rapidly colonized by HS- oxidizing bacteria tentatively assigned to the family Beggiatoaceae, and HS- release was completely suppressed. The presence of a hypoxic transition zone (HTZ) between 80 and 120 m water depth was confirmed not only for euxinic deep-water conditions during 2013 but also for post-inflow conditions. Because deep-water renewal did not ventilate the HTZ, where PO43- and NH4+ fluxes were highest, high seabed nutrient release there was relatively unchanged. Extrapolation of the in situ nutrient fluxes indicated that, overall, the reduction in PO43- and NH4+ release in response to deep-water renewal can be considered as minor, reducing the internal nutrient load by 2 and 12 % only, respectively. Infrequent inflow events thus have a limited capacity to sustainably reduce internal nutrient loading in the EGB and mitigate eutrophication.

Synchronous deglacial thermocline and deep-water ventilation in the eastern equatorial Pacific

The deep ocean is most likely the primary source of the radiocarbon-depleted CO2 released to the atmosphere during the last deglaciation. While there are well-documented millennial scale Δ14C changes during the most recent deglaciation, most marine records lack the resolution needed to identify more rapid ventilation events. Furthermore, potential age model problems with marine Δ14C records may obscure our understanding of the phase relationship between inter-ocean ventilation changes. Here we reconstruct changes in deep water and thermocline radiocarbon content over the last deglaciation in the eastern equatorial Pacific (EEP) using benthic and planktonic foraminiferal 14C. Our records demonstrate that ventilation of EEP thermocline and deep waters occurred synchronously during the last deglaciation. In addition, both gradual and rapid deglacial radiocarbon changes in these Pacific records are coeval with changes in the Atlantic records. This in-phase behaviour suggests that the Southern Ocean overturning was the dominant driver of changes in the Atlantic and Pacific ventilation during deglaciation.

Intense ventilation of the Black Sea pycnocline due to vertical turbulent exchange in the Rim Current area

This paper presents new observational data, which indicate that deep ventilation events in the aerobic zone extending across the upper part of the permanent pycnocline may occur sporadically in the Rim Current area, even during relatively warm seasons, when the seasonal thermocline is still notable. The strongest observed event of this type occurred on November 2014 off the continental shelf break near Gelendzhik Bay. Vertical profiles of dissolved oxygen were accurately measured using an SBE 52-MP Conductivity, Temperature, Depth (CTD) probe equipped with a fast-response SBE 43F oxygen sensor mounted on a moored Aqualog automatic mobile profiler. The analysis of the profiling data from October 6 through December 16, 2014, from depths between 35m and 215m revealed an anomaly on November 6–7. The dissolved oxygen exceeded the background levels by more than 0.2ml/l (8.9μM) at the 14.9–15.7kg/m3 isopycnals in the pycnocline and reached approximately 1ml/l (44.66μM) for short periods. The peak absolute value of the dissolved oxygen reached an exceptionally high value of approximately 0.3ml/l (13.4μM) at the 15.9kg/m3 isopycnal. The ventilation event increased the temperature by ~0.2°C at depths of 120–160m. The simultaneous observations of both the thermohaline stratification and the ocean currents suggest that the ventilation event was associated with the sinking of pycnocline waters in the near-bottom Ekman layer along the continental slope and intense vertical turbulent exchange in the Rim Current area near the continental slope. The ventilation of the pycnocline when the overlaying upper ocean is stably stratified sharply differs from the convection reaching the Cold Intermediate Layer during extensive cooling of the sea surface. Indications of such ventilation events were also found in the Aqualog mooring data archive from 2012.

Genesis of Cryogenian Datangpo manganese deposit: Hydrothermal influence and episodic post-glacial ventilation of Nanhua Basin, South China

The Neoproterozoic Datangpo Formation of the Nanhua Basin in South China records interglacial sedimentation between the ~720–660-Ma Sturtian and ~654–635-Ma Marinoan glaciations. The lower part (1st Member) of this formation contains manganese-rich deposits that represent a mixture of two main components, Mn-carbonates and Mn-bearing aluminosilicates (clay minerals). The Mn-carbonate component is characterized by high La/Sc ratios, high initial 87Sr/86Sr ratios, and low initial εNd(t) values, and the siliciclastic component by low La/Sc ratios, low initial 87Sr/86Sr ratios, and high initial εNd(t) values. The likely source of the non-radiogenic siliciclastic material is weathering of Neoproterozoic continental flood basalts on the Yangtze Block. Discriminant plots show that the Mn-ore samples have compositions consistent with at least partial derivation from hydrothermal sources. Mn-carbonate deposition was the result of reactions between aqueous Mn and sedimentary organic matter during early diagenesis that led to elevated Mn2+ concentrations and alkalinity in sediment porewaters. Based on these observations, we propose a new metallogenic model for the Datangpo Formation manganese deposits. During the Sturtian glaciation, the anoxic Nanhua Basin accumulated abundant dissolved Mn, a substantial fraction of which was derived from hydrothermal sources. When glaciation ended and a redox-stratified water column developed in the basin with an oxic surface layer and an anoxic deep layer, the accumulated dissolved Mn precipitated as Mn-oxides on the basin floor during episodic ventilation events. After co-burial with organic-rich sediments, these Mn-oxides were reduced during organic matter oxidation, which led to the formation of secondary Mn-carbonates (rhodochrosite) through increases in sediment porewater Mn2+ and in alkalinity via microbial sulfate reduction and microbially mediated Mn reduction.

Coastal recirculation potential affecting air pollutants in Portugal: The role of circulation weather types

Coastal zones are under increasing development and experience air pollution episodes regularly. These episodes are often related to peaks in local emissions from industry or transportation, but can also be associated with regional transport from neighbour urban areas influenced by land-sea breeze recirculation.This study intends to analyze the relation between circulation weather patterns, air mass recirculation and pollution levels in three coastal airsheds of Portugal (Lisbon, Porto and Sines) based on the application of an objective quantitative measure of potential recirculation.Although ventilation events have a dominant presence throughout the studied 9-yrs period on all the three airsheds, recirculation and stagnation conditions occur frequently. The association between NO2, SO2 and O3 levels and recirculation potential is evident during summer months. Under high average recirculation potential and high variability, NO2 and SO2 levels are higher for the three airsheds, whilst for O3 each airshed responds differently. This indicates a high heterogeneity among the three airsheds in (1) the type of emission – traffic or industry – prevailing for each contaminant, and (2) the response to the various circulation weather patterns and recirculation situations. Irrespectively of that, the proposed methodology, based on iterative K-means clustering, allows to identify which prevailing patterns are associated with high recirculation potential, having the advantage of being applicable to any geographical location.

Upper Jurassic Tithonian-centered source mapping in the deepwater northern Gulf of Mexico

Long the subject of speculation, the origin, distribution, and quality of Mesozoic source beds in the deepwater Gulf of Mexico (GOM) are now open to analytical study and hypothesis. We have developed new maps and concepts for organic richness and lithofacies patterns of the primary Upper Jurassic oil-prone source rock interval spanning the Kimmeridgian to Lower Berriasian in the northern GOM. This interval, previously referred to as the Tithonian-centered source, includes the Haynesville and Bossier shales, which lie within supersequences representing second-order transgressive and high-stand systems tracts, respectively. A newly developed gulf-wide Cotton Valley-Bossier paleogeographic map based on a novel paleotectonic model for the Mesozoic provides the framework for this source mapping study. Organic richness averages up to 4.7% and 6.5% total organic carbon for the Kimmeridgian and Tithonian-Lower Berriasian supersequences, respectively, based on the log overlay [Formula: see text] technique and increases toward the basin center. Lithofacies-sensitive geochemical parameters from reservoired oils and oil seeps tied to the Tithonian-centered oil family demonstrate several potential entry locations for siliciclastic sediments into the Tithonian distal calcareous environment. The region from Garden Banks to Alaminos Canyon appears to be the locus of siliciclastic mixing with carbonates in the deepwater and link with updip evidence of a wide progradational clastic apron sourced by the paleo-Mississippi river. This siliciclastic input may contribute to the potential for improved oil quality by lowering the content of sulfur incorporated into kerogen moving southwest from Ewing Bank-Mississippi Canyon to Alaminos Canyon. Ultimately, enhanced Upper Jurassic source deposition ended with a ventilation event whereby more oxygenated, deeper water entered the northern GOM. Declines in calculated total organic carbon occurring later to the west during the earliest Cretaceous (Berriasian) indicate the opening of the gateway between the GOM and the central Atlantic possibly related to the termination of seafloor spreading in the eastern GOM.

Ventilator-Related Adverse Events: A Taxonomy and Findings From 3 Incident Reporting Systems.

In 2009, researchers from Johns Hopkins University's Armstrong Institute for Patient Safety and Quality; public agencies, including the FDA; and private partners, including the Emergency Care Research Institute and the University HealthSystem Consortium (UHC) Safety Intelligence Patient Safety Organization, sought to form a public-private partnership for the promotion of patient safety (P5S) to advance patient safety through voluntary partnerships. The study objective was to test the concept of the P5S to advance our understanding of safety issues related to ventilator events, to develop a common classification system for categorizing adverse events related to mechanical ventilators, and to perform a comparison of adverse events across different adverse event reporting systems. We performed a cross-sectional analysis of ventilator-related adverse events reported in 2012 from the following incident reporting systems: the Pennsylvania Patient Safety Authority's Patient Safety Reporting System, UHC's Safety Intelligence Patient Safety Organization database, and the FDA's Manufacturer and User Facility Device Experience database. Once each organization had its dataset of ventilator-related adverse events, reviewers read the narrative descriptions of each event and classified it according to the developed common taxonomy. A Pennsylvania Patient Safety Authority, FDA, and UHC search provided 252, 274, and 700 relevant reports, respectively. The 3 event types most commonly reported to the UHC and the Pennsylvania Patient Safety Authority's Patient Safety Reporting System databases were airway/breathing circuit issue, human factor issues, and ventilator malfunction events. The top 3 event types reported to the FDA were ventilator malfunction, power source issue, and alarm failure. Overall, we found that (1) through the development of a common taxonomy, adverse events from 3 reporting systems can be evaluated, (2) the types of events reported in each database were related to the purpose of the database and the source of the reports, resulting in significant differences in reported event categories across the 3 systems, and (3) a public-private collaboration for investigating ventilator-related adverse events under the P5S model is feasible.