The development of two Arctic Trough Mouth Fans (TMFs), the Storfjorden and Kveithola TMFs, is investigated by means of sub-bottom and seismic reflection profiles, multibeam bathymetry and sediment samples allowing their detailed stratigraphic architecture to be defined. We find that the TMFs mainly consist of an alternation of rapidly deposited glacigenic debris flows during glacial maxima and a sequence of well-layered plumites and hemipelagic sediments, which were mainly deposited during the deglaciation phase of the adjacent glacial trough. We have identified eight units above regional reflector R1, which indicate that the ice sheet reached the shelf edge within the Storfjorden Trough on at least three occasions during the last similar to 200 ka. A shallow subsurface unit of glacigenic debris flows suggests that the ice sheet had a short re-advance over the northern and central part of Storfjorden after the Last Glacial Maximum. From stratigraphy, core and literature data, we estimate that ice sheets reached the shelf edge between 19.5 to 22.5 ka, 61 to 65 ka and 135 to 167 ka. Detailed seismic imaging allows us to refine the sedimentary model of Arctic TMFs. The main differences to previous models involve gully formation during not only the deglaciation phase, but also during interglacials by dense shelf water cascading, and a specific timing for the occurrence of slope failures (i.e., shortly after the deglaciation phase). High mean sedimentation rates during glacial maxima of up to 18 kg m(-2) yr(-1) likely allow excess pore pressure to develop in the water rich plumites and hemipelagic sediments deposited in the previous deglacial period, particularly where such plumites attain a significant thickness. The position of the submarine landslides in the stratigraphic record suggest that such excess pore pressure is not enough to trigger the slope failures and suggests that earthquakes related to isostatic rebound are likely involved in the final activation. (C) 2015 Elsevier Ltd. All rights reserved.

Net-depositional submarine canyons are common in continental slope strata, but how they survive and prograde on constructional margins is poorly understood. In this study we present field evidence for the coevolution of a submarine canyon and the adjacent continental slope. Using a three-dimensional seismic data cube that images the Ebro margin (northwest Mediterranean), we identify a preserved canyon on a middle Pleistocene paleosurface and relate it directly to its expression on the present-day seafloor. A subparallel stacking pattern of seismic reflectors, similar to that seen between prograding clinoforms in intercanyon areas, is observed between the modern and paleocanyon thalwegs. The concavity of the modern long profile differs from the convex-concave long profile on the middle Pleistocene surface, suggesting a long-term change in canyon sedimentation. We interpret this change as a shift to a canyon dominated by turbidity currents from one strongly influenced by the pattern of sedimentation that built the open-slope canyon interfluves. We find support for our interpretation in previous studies of the Ebro margin.

The studied area appears as a major place for dense shelf water (DSW) formation and export towards the deep basin with Blanes and La Fonera canyons as most efficient pathways. These two canyons are so deeply indented on the continental shelf and slope of the northern Catalan margin (Western Mediterranean Sea) that their heads significantly reduce the width of the shelf and interfere with coast and contour parallel sediment transport patterns. This study presents the results of the analysis of swath bathymetry data and parametric seismic reflection profiles showing the detailed morphology and uppermost sedimentary structure of Blanes and La Fonera canyons, with the focus on their heads and adjacent upper courses and shelf. The main aim is to understand their functioning and assess how they influence and respond to the hydrosedimentary processes active in the study area.The N–S oriented Blanes canyon head, whose shortest distance to shore is only 4km, extends along 21.7km from 70 to 1300m water depth with an average rim to rim width of 8km and a canyon floor width up to 750m. La Fonera canyon head extends along 28km from 60 to 1700m water depth. Rim to rim and canyon floor widths are up to 7km and up to 700m, respectively. The canyon head follows a general WNW–ESE trending course in its deeper part, but trends N–S in its shallower course formed by Cap Begur branch. South of it, the Illa Negra branch trends NW–SE and its tip, located at 60m water depth and 800m from the coastline, intersects the littoral sedimentary prism. Backscatter data show high reflectivity into both Blanes and La Fonera canyon floors as well as on tributary gullies, which at these locations is indicative of coarse sediment.The seafloor and subseafloor observations here presented are explained and best understood, from the sedimentological viewpoint, by the interplay of event-driven DSW flows, permanent mesoscale circulation and storm action. While DSW flows from the Gulf of Lion and the shelf area around the studied canyons are the most dynamic agent in terms of sediment transport and seafloor shaping, the Northern Current ensures background sedimentation of fines, and coastal storms promote episodic entries through canyon heads and upper course rims. Canyon wall morphology and sediment draping respond to the currentward or leeward position of each wall with respect to the main, southward moving water flows in the area, either episodic or permanent, that are DSW and the Northern Current. Other relevant morphosedimentary features, such as a 40km long, southbound subdued channel on the Roses outer shelf that originates off Cap de Creus promontory to finally feed Cap Begur branch of La Fonera canyon and a contouritic ridge and moat attached to the northern wall of the canyon are interpreted in terms of DSW flows.A comprehensive model of the sedimentary functioning of the canyoned north Catalan margin that integrates seafloor information and background data on dynamic processes is presented, which could be of application to other continental margins worldwide. Such an integrative view is eased by the enormous, unprecedented multidisciplinary research effort carried out in the study area over the last three decades.

This study aims to present an overview of the seafloor morphology and shallow sedimentary structure of the Storfjorden and Kveithola Trough Mouth Fans (TMFs) on the northwestern Barents Sea continental margin. Data have been compiled from two International Polar Year (IPY) cruises (SVAIS, of the BIO Hespérides and EGLACOM of the R/V OGS-Explora) that yielded 15,340km2 of multi-beam bathymetry and 9500km of sub-bottom seismic profiles. In this area, the continental shelf edge defines three wide and subdued sedimentary lobes forming Storfjorden TMF, one single lobe on Kveithola TMF, and three inter-TMF areas on the continental slope. The two northernmost lobes of Storfjorden TMF (Lobes I and II) are composed by thick (up to 50m) sequences of glacially derived debris flow deposits interbedded with thin a few metres de-glacial and interglacial deposits. A network of upper slope gullies incises these debris flow deposits as a consequence of subglacial meltwater release at or near the shelf break. Gullies evolve into channels whose morphologic evidence disappears midslope, leaving place to a subdued chevron-like morphological pattern inherited by the preceeding glacial maximum debris flow deposits. A drastic change occurs on the continental slope of Storfjorden TMF Lobe III and Kveithola TMF, where are several translational submarine landslides mostly originated in the upper slope, the majority of which detach at the contact between Middle Weishelian glacigenic debris flows and the overlying acoustically laminated plumites. Dendritic canyon systems only develop in inter-TMF areas. The data suggest that TMF continental slope progradation depends on short-lived episodes of extreme sedimentation during glacial maxima and during the early deglaciation phase, and that an important controlling factor is the mechanism of ice stream retreat from the continental shelf edge. We suggest that the two northern Storfjorden sub-ice streams were composed of thicker and perhaps faster ice progressively draining a distal and larger ice source mainly located on Svalbard. Conversely, the southernmost Storfjorden sub-ice stream and the Kveithola ice stream were fed by a local, smaller marine-based ice dome grounded on Spitsbergenbanken. The ice dome persisted after the LGM, maintaining a local ice drainage system close to the shelf edge whose sedimentary evidence can be found on the continental slope of the southern lobe of Storfjorden TMF and Kveithola TMF. The high degree of lateral variability in the style of sedimentation on TMF slopes suggests that ice stream dynamics may vary considerably within the same glacial trough, and that such variability affects the long-term development of the architecture of TMFs.

Recent investigations of the Eastern Mediterranean Sea carried out during the GECO cruise with RV Urania provided a substantial number of new cold-water coral (CWC) records, including branching and solitary scleractinian species. These new sites are located along steep escarpments and on topographic highs along the margins of Crete, Karpathos, and Rhodes. The majority of the corals represent fossil occurrences, predominantly Late Pleistocene assemblages. Our research documents that the Eastern Mediterranean Basin has been colonized by CWC at favorable times during the Last Glacial, in particular during the Younger Dryas. Schizocyathus fissilis is reported for the first time for the Mediterranean, while the finding of Ceratotrochus magnaghii represents the first record for the Eastern Mediterranean. Various coral facies occur on the southerly island slopes of Crete, Karpathos, and Rhodes, including hardgrounds and loose skeletal sediments. Hardgrounds occur on steep topographies between ca. 500 and 1,700 m, and can conveniently be subdivided as (1) Neopycnodonte-Desmophyllum framestone, (2) Desmophyllum-Caryophyllia framestone, (3) Madrepora-Lophelia rudstone, (4) Pelagic mudstone and wackestone, and (5) Siliciclastic-carbonate conglomerate and breccia. Unconsolidated skeletal sediments containing corals mainly occur on gentler topographic situations between ca. 140 and 600 m and can be subdivided as: (A) Lophelia-Madrepora rubble, (B) Dendrophyllia rubble, (C) Stenocyathus rubble, (D) Caryophyllia calveri rubble, and (E) fine-grained sediment with octocoral axes. Many of these facies types are also present in the western part of the Mediterranean and have fossil representatives from the Pleistocene to the Recent. Radiocarbon dating (AMS-14C) reveals Younger Dryas ages between 12.4 and 12.0 ka cal BP for Lophelia pertusa and Madrepora oculata. Desmophyllum dianthus occurs during the Last Glacial Maximum (21.8 ka cal BP) and the Younger Dryas (11.7 ka cal BP), as well as during the Late Holocene and subrecent times (4.4–0.6 ka cal BP). Caryophyllia sarsiae occurs during the Late Glacial (15.5 ka cal BP), while Caryophyllia calveri occurs during the Early Preboreal (10.8 ka cal BP). The ages for the framework-constructing corals L. pertusa and M. oculata are coherent with their temporal predominance during the Younger Dryas in other parts of the Mediterranean.

Endoscopic vein-graft harvesting for coronary bypass grafting: good results in patients at risk for surgical site infection

The deep sea, the largest biome on Earth, has a series of characteristics that make this environment both distinct from other marine and land ecosystems and unique for the entire planet. This review describes these patterns and processes, from geological settings to biological processes, biodiversity and biogeographical patterns. It concludes with a brief discussion of current threats from anthropogenic activities to deep-sea habitats and their fauna.Investigations of deep-sea habitats and their fauna began in the late 19th century. In the intervening years, technological developments and stimulating discoveries have promoted deep-sea research and changed our way of understanding life on the planet. Nevertheless, the deep sea is still mostly unknown and current discovery rates of both habitats and species remain high. The geological, physical and geochemical settings of the deep-sea floor and the water column form a series of different habitats with unique characteristics that support specific faunal communities. Since 1840, 28 new habitats/ecosystems have been discovered from the shelf break to the deep trenches and discoveries of new habitats are still happening in the early 21st century. However, for most of these habitats the global area covered is unknown or has been only very roughly estimated; an even smaller - indeed, minimal - proportion has actually been sampled and investigated. We currently perceive most of the deep-sea ecosystems as heterotrophic, depending ultimately on the flux on organic matter produced in the overlying surface ocean through photosynthesis. The resulting strong food limitation thus shapes deep-sea biota and communities, with exceptions only in reducing ecosystems such as inter alia hydrothermal vents or cold seeps. Here, chemoautolithotrophic bacteria play the role of primary producers fuelled by chemical energy sources rather than sunlight. Other ecosystems, such as seamounts, canyons or cold-water corals have an increased productivity through specific physical processes, such as topographic modification of currents and enhanced transport of particles and detrital matter. Because of its unique abiotic attributes, the deep sea hosts a specialized fauna. Although there are no phyla unique to deep waters, at lower taxonomic levels the composition of the fauna is distinct from that found in the upper ocean. Amongst other characteristic patterns, deep-sea species may exhibit either gigantism or dwarfism, related to the decrease in food availability with depth. Food limitation on the seafloor and water column is also reflected in the trophic structure of heterotrophic deep-sea communities, which are adapted to low energy availability. In most of these heterotrophic habitats, the dominant megafauna is composed of detritivores, while filter feeders are abundant in habitats with hard substrata (e. g. mid-ocean ridges, seamounts, canyon walls and coral reefs). Chemoautotrophy through symbiotic relationships is dominant in reducing habitats.Deep-sea biodiversity is among of the highest on the planet, mainly composed of macro and meiofauna, with high evenness. This is true for most of the continental margins and abyssal plains with hot spots of diversity such as seamounts or cold-water corals. However, in some ecosystems with particularly "extreme" physicochemical processes (e.g. hydrothermal vents), biodiversity is low but abundance and biomass are high and the communities are dominated by a few species. Two large-scale diversity patterns have been discussed for deep-sea benthic communities. First, a unimodal relationship between diversity and depth is observed, with a peak at intermediate depths (2000-3000 m), although this is not universal and particular abiotic processes can modify the trend. Secondly, a poleward trend of decreasing diversity has been discussed, but this remains controversial and studies with larger and more robust data sets are needed. Because of the paucity in our knowledge of habitat coverage and species composition, biogeographic studies are mostly based on regional data or on specific taxonomic groups. Recently, global biogeographic provinces for the pelagic and benthic deep ocean have been described, using environmental and, where data were available, taxonomic information. This classification described 30 pelagic provinces and 38 benthic provinces divided into 4 depth ranges, as well as 10 hydrothermal vent provinces. One of the major issues faced by deep-sea biodiversity and biogeographical studies is related to the high number of species new to science that are collected regularly, together with the slow description rates for these new species. Taxonomic coordination at the global scale is particularly difficult, but is essential if we are to analyse large diversity and biogeographic trends.Because of their remoteness, anthropogenic impacts on deep-sea ecosystems have not been addressed very thoroughly until recently. The depletion of biological and mineral resources on land and in shallow waters, coupled with technological developments, are promoting the increased interest in services provided by deep-water resources. Although often largely unknown, evidence for the effects of human activities in deep-water ecosystems - such as deep-sea mining, hydrocarbon exploration and exploitation, fishing, dumping and littering - is already accumulating. Because of our limited knowledge of deep-sea biodiversity and ecosystem functioning and because of the specific life-history adaptations of many deep-sea species (e. g. slow growth and delayed maturity), it is essential that the scientific community works closely with industry, conservation organisations and policy makers to develop robust and efficient conservation and management options.

This study reports for the first time on the occurrences of deep-water coral species in the Spanish territorial waters of the Strait of Gibraltar. Based on an extensive dataset of 334 grab samples, 16 species of calcareous corals have been identified in water depths between 13-443 m. Scleractinian corals form the dominant benthic community between 140-330 m water depth. The corals appear on the seabed both as solitary individuals and as patches on small biological topographic build-ups. The most common coral species Lophelia pertusa and Madrepora oculata are associated with coarse-grained calcareous sediments and mound structures. In the shallowest part of the study area (< 150 m) algae and bryozoans are dominant and only a few coral species are observed. This zonation and the occurrence of the azooxanthellate corals in the Strait of Gibraltar relates to light availability and perhaps also to the complex interaction between the outflow of Mediterranean water and surficial inflow of Atlantic water into the Mediterranean Sea.

This paper presents an overview of the spatial distribution and morphology of coral banks in the Porcupine Seabight in relation to their environmental settings. The study area is characterised by well-delimited clusters of coral banks, each featuring typical bank morphology and environmental setting. In the central part of the basin, two mound provinces can be identified: a set of complex flat topped seafloor mounds in the Hovland Mound province is flanked to the north by a crescent of numerous north-south elongated buried coral banks in the Magellan Mound province, along the eastern margin of the basin partly buried and seabed coral banks represent the Belgica Mound province. The banks are mound-shaped elevations, many of them hosting living deep-water corals (Lophelia pertusa, Madrepora oculata, Desmophyllum cristagalli, Dendrophyllia sp.) and associated fauna. This active biological layer covers a dead assemblage of corals clogged with mud. All coral banks, buried or seabed, occur in association with current-induced features (e.g., scouring features, dunes) and steep palaeo- and present-seabed slopes. Only a few banks have a present-day seabed expression, which suggests that environmental conditions have been more favourable for bank development in the past. The depth range of the seabed coral banks coincides with the Mediterranean Outflow Water which may control indirectly the coral distribution. The distribution of corals in the southern part of the North Atlantic and the actual link with Mediterranean water suggest a possible migration of corals within the Mediterranean water along the NE Atlantic margin. The start-up phase of the coral bank development in the basin has taken place simultaneously for all provinces, and tentatively framed in times subsequent to a Late Pliocene period of erosion and non-deposition. It is considered that the sedimentary load of the currents plays an important role in the batik development. Coral banks accrete by the active baffling of sediment by the biological framework and growth of the biological cap. When sedimentation and biological growth get out of balance, the framework will progressively be clogged with sediment. Once sediment dominates the structure the coral banks get buried and draped by sediment.

Objective. To establish the usability, reliability, and validity of the Critical Nursing Situation-Index (CNSI), a list of 84 observable deviations from good clinical care, which could place the patient at risk. Design. Descriptive. Method. Instructions from nursing standards and protocols were translated into 84 possible observable deviations from usual care (split over 8 care groups, such as artificial respiration and infusion), selected on the basis of risk and included in the index. A research nurse observed the care provided to patients in January-March 1999 from 07.00 to I8.00 hours, at the Intensive Care Unit (ICU) for adults (30 beds) at the Academic Medical Centre, University of Amsterdam. Patient selection was on a randomised basis using the bed numbers. The ICU nurses were blinded for the index items. Inter-observer agreement (K) was determined by a staff nurse simultaneously observing to patients (840 items). Validity was tested on the basis of the correlation between the amount of time available per patient (≤ versus > 30 min/h) and the number of mistakes observed. Results. The CNSI was applied 200 times to 83 ICU patients. The time needed to carry out I observation (84 items) was 5-I0 minutes per patient. The average K was 0.83 (range 0.70-0.80). The construct validity was expressed in the form of a relative risk whereby less nursing time resulted in more critical situations (higher index score: 1.36 (95% CI: 1.11-1.67)). Conclusion. The index was highly usable, has good measurement characteristics and provided information about the quality of care provided as well as the safety of patients.

The Porcupine Seabight is an embayment that takes a particular position in the NE Atlantic slope. Sonographs, a few current measurements and hydrodynamic modelling suggest the presence of a strong northward-flowing bottom current, locally enhanced by internal tides, affecting the eastern slope of the Seabight. At this location a province of coral banks is described, expressed as mounds lined up in along-slope-trending ridges. In this paper, very high-resolution single-channel seismic profiles are used to evaluate to what extent the bottom currents influenced the deposition of the sediments surrounding the mounds throughout the Late Cenozoic. Three seismostratigraphic units (P1, P2 and P3) can be identified in the Belgica mound area, separated by two margin-wide discontinuities (RD2 and RD1). Within Unit P1 (probably Early to Middle Miocene) upslope-migrating sediment waves are observed, suggesting strong bottom currents were already active in the Miocene. After an early Middle Miocene erosion event, represented by reflector RD2, an acoustically transparent layer (Unit P2) of as yet unknown lithology was deposited in the studied area. A second margin-wide erosional event, marked by the Late Pliocene RD1 reflector, removed a large part of Unit P2 and has cut deeply into Unit P1. Subsequently, the Belgica mounds were constructed spectacularly fast on topographic irregularities on the RD1 paleobathymetry. The onlap within the Quaternary Unit P3, which surrounds these mounds, suggests that the mounds were already present before the deposition of P3 and were big enough to affect the intensity of the currents around them. Furthermore, the channels and the mounds are, together with the complex oceanographic regime, the key morphological elements responsible for the shaping of a contourite system in the Belgica mound area during the Quaternary. One drift body is formed by an inferred south–north-directed current, with a drift levee and associated channel located on its western side. Between this channel and the mounds, large-scale sediment waves suggest an intensified bottom current running along the foot of the steep flanks of the mounds. The Belgica mounds are embedded in another drift body. Here, an interaction of bottom and turbidity currents is suggested, creating short turbidite channels at the southern and northern flanks of the mounds. Locally, small confined drifts can be observed where Unit P3 is deposited in a narrow passage made by the paleobathymetry of RD1 and the mounds.

An industrial 3D seismic data volume, supplemented by high-resolution 2D seismics, was used to study part of a province of buried mound structures in the Porcupine Basin, southwest of Ireland. These 'Magellan' mounds and their associated moat structures, interpreted as scour marks, were mapped semi-automatically from time-structure and isopach maps. Image analysis techniques such as a tophat transformation (mathematical morphology) were applied for feature extraction. Size measures of both mounds and moats were derived from the resulting maps and summarised by means of some descriptive statistics. Spatial variability in mound occurrence and characteristics was investigated. Comparison with other mound structures in the area allowed the Magellan mounds to be identified as 'coral banks', associated with the growth of cold-water deep-sea coral species such as Lophelia pertusa (L.) and Madrepora oculata (L.). Mound growth clearly started in a single 'event', confined in time and space. Bottom currents and oceanographic characteristics of the surrounding water masses influenced this sudden process and the further mound development. However, the analysis of the 3D seismic data set did not allow us to identify unambiguously the actual cause for the sudden mound start-up. The mounds appear to have formed a dense cluster of structures of moderate size, which are significantly elongated in a N–S direction. They are associated with even more elongated moats, implying a periodically reversing N–S-directed current influence. A spatial density of one mound per km2 was measured, which remains more or less constant over the area investigated. Mound width and cross-sectional area and moat shape gradually change across the mound province, due to spatially changing environmental conditions at the initial growth stages of the mounds and during their further development (interplay between current regime and sedimentation).

The Porcupine Basin, southwest of Ireland, was one of the earliest sites from where the deep-water corals Lophelia sp. and Madrepora sp. were recovered. These deep-water corals have since been found all along the Atlantic margins of Europe, in water depths ranging from 50 to more than 2000 m. Recent geophysical studies have demonstrated the mound-building potential of deep-water corals. Available data indicate that three major provinces of coral bank occurrences can be identified in the Porcupine Basin: (1) high-relief surface mounds which have a dimension of 1 by 5 km and a height up to 200 m (‘Hovland’ mounds), flanked to the north by (2) a swarm of buried mounds, somewhat smaller (up to 90 m), and with more irregular shapes than those recognised in area 1 (‘Magellan’ mounds), and (3) outcropping or buried, conical mounds (single or in elongated clusters, up to 150 m high) occurring on the southeastern slope of the basin (‘Belgica’ mounds). As far as can be inferred from shallow cores, the surface lithology predominantly consists of an upper layer rich in foraminiferal sand and terrigenous silty clay with intercalations of biogenic rubble. The banks host a remarkable number of colonies of living and dead Lophelia pertusa and Madrepora oculata. The living and dead assemblages are underlain by a significant layer of coral debris in a muddy matrix. Deep-water coral debris together with a living association of the same species covers the surface of the ‘Belgica’ and ‘Hovland’ mounds, which may suggest that these corals have played a significant role in the development of the mound structures. The capacity for mound formation by scleractinian corals in the aphotic zone has been known for some time. Examples are found at different locations along the shelves and the continental margins of the North Atlantic. The role of the corals in these deep-water build-ups is still a point of debate. Though the genesis and initial control of mound settings in this basin might be related to hydrocarbon seeps, it appears that the major development of the Porcupine coral banks in recent geological times has most likely been controlled by oceanic circulation and dynamics in water masses and nutrient supply.

Abstract High-resolution reflection seismic investigations carried out in the Porcupine Basin, SW of Ireland, have shed light on the presence of several provinces of giant carbonate mounds. An intriguing setting is found on the northern slope of the basin. A cluster of surface mounds appears to be flanked by a large upslope, crescent-shaped province of buried mounds. Below the transitional zone, large imbricated slide scars suggest repeated failures. The buried mounds rise from an undisturbed basal horizon and seem to represent a single event, confined in time and space. Both high-resolution and industrial seismic data reveal a close vertical match of the mound cluster with a lower, buried sea-bed failure, where hydrate build-up may have played a role. The latter association may not be entirely fortuitous. It is suggested that gas venting may have triggered the formation of the mound clusters, and that the underlying sea-bed failure forms a previous but different expression of gas venting, on a common, episodic fluid migration pathway but under strongly contrasting bottom water temperature conditions.

Besides renal failure and mesenteric infarction, spinal cord ischemia is the most dreaded complication after thoracoabdominal aortic surgery. Several techniques have been developed to improve neurologic outcome of these massive surgical procedures, including pharmacologic adjuncts, epidural cooling, distal aortic perfusion, cerebrospinal fluid drainage, and reattachment of segmental arteries. The authors developed a technique to assess spinal cord integrity as part of the surgical protocol, dictating operative strategies to restore blood supply to the endangered grey matter. Monitoring motor evoked potentials (MEPs) was performed in experimental studies and in 170 patients with a thoracoabdominal aortic aneurysm. The surgical protocol included left heart bypass and cerebrospinal fluid drainage, and MEP monitoring was applied to identify critical intercostal and lumbar arteries. Based on MEPs, the aggressive surgical approach resulted in a significant reduction of neurologic complications (2.3%).