The purpose of this study was to determine the potential for the Pentax AWS® and the Glidescope® to reduce the difficulty of tracheal intubation in patients at increased risk for difficult tracheal ...intubation, in a randomized, controlled clinical trial.
Seventy-five consenting patients presenting for surgery requiring tracheal intubation, and who were deemed to possess characteristics indicating an increased risk for difficult tracheal intubation, were randomly assigned to undergo intubation using a Macintosh, AWS®, or Glidescope® laryngoscope (n=25 patients per group). All patients were intubated by one of three anaesthetists experienced in the use of each laryngoscope.
Both the Glidescope® and the AWS® significantly reduced the intubation difficulty score compared with the Macintosh. The rate of successful tracheal intubation was lower with the Macintosh (84%) compared with the Glidescope® (96%) or the AWS® (100%). There were no differences in the duration of tracheal intubation attempts between the devices. Both the Glidescope® and the AWS® significantly reduced the need for additional manoeuvres and improved the Cormack and Lehane view obtained at laryngoscopy, compared with the Macintosh. Tracheal intubation with the AWS® but not the Glidescope® reduced the degree of haemodynamic stimulation compared with the Macintosh laryngoscope.
The AWS® and the Glidescope® laryngoscopes reduced the difficulty of tracheal intubation to a similar extent compared with the Macintosh laryngoscope, in patients at increased risk for difficult tracheal intubation.
Summary
The C‐MAC® comprises a Macintosh blade connected to a video unit. The familiarity of the Macintosh blade, and the ability to use the C‐MAC as a direct or indirect laryngoscope, may be ...advantageous. We wished to compare the C‐MAC with Macintosh, Glidescope® and Airtraq® laryngoscopes in easy and simulated difficult laryngoscopy. Thirty‐one experienced anaesthetists performed tracheal intubation in an easy and difficult laryngoscopy scenario. The duration of intubation attempts, success rates, number of intubation attempts and of optimisation manoeuvres, the severity of dental compression, and difficulty of device use were recorded. In easy laryngoscopy, the duration of tracheal intubation attempts were similar with the C‐MAC, Macintosh and Airtraq laryngoscopes; the Glidescope performed less well. The C‐MAC and Airtraq provided the best glottic views, but the C‐MAC was rated as the easiest device to use. In difficult laryngo‐scopy the C‐MAC demonstrated the shortest tracheal intubation times. The Airtraq provided the best glottic view, with the Macintosh providing the worst view. The C‐MAC was the easiest device to use.
The rapidly warming temperatures in high-latitude and alpine regions have the potential to alter the phenology of Arctic and alpine plants, affecting processes ranging from food webs to ecosystem ...trace gas fluxes. The International Tundra Experiment (ITEX) was initiated in 1990 to evaluate the effects of expected rapid changes in temperature on tundra plant phenology, growth and community changes using experimental warming. Here, we used the ITEX control data to test the phenological responses to background temperature variation across sites spanning latitudinal and moisture gradients. The dataset overall did not show an advance in phenology; instead, temperature variability during the years sampled and an absence of warming at some sites resulted in mixed responses. Phenological transitions of high Arctic plants clearly occurred at lower heat sum thresholds than those of low Arctic and alpine plants. However, sensitivity to temperature change was similar among plants from the different climate zones. Plants of different communities and growth forms differed for some phenological responses. Heat sums associated with flowering and greening appear to have increased over time. These results point to a complex suite of changes in plant communities and ecosystem function in high latitudes and elevations as the climate warms.
The purpose of this study was to evaluate the effectiveness of the Pentax AWS®, Glidescope®, and the Truview EVO2®, in comparison with the Macintosh laryngoscope, when performing tracheal intubation ...in patients with neck immobilization using manual in-line axial cervical spine stabilization.
One hundred and twenty consenting patients presenting for surgery requiring tracheal intubation were randomly assigned to undergo intubation using a Macintosh (n=30), Glidescope® (n=30), Truview EVO2® (n=30), or AWS® (n=30) laryngoscope. All patients were intubated by one of the three anaesthetists experienced in the use of each laryngoscope.
The Glidescope®, AWS®, and Truview EVO2® each reduced the intubation difficulty score (IDS), improved the Cormack and Lehane glottic view, and reduced the need for optimization manoeuvres, compared with the Macintosh. The mean IDS was significantly lower with the Glidescope® and AWS® compared with the Truview EVO2® device, and the IDS was lowest with the AWS®. The duration of tracheal intubation attempts was significantly shorter with the Macintosh compared with the other devices. There were no differences in success rates between the devices tested. The AWS® produced the least haemodynamic stimulation.
The Glidescope® and AWS® laryngoscopes required more time but reduced intubation difficulty and improved glottic view over the Macintosh laryngoscope more than the Truview EVO2® laryngoscope when used in patients undergoing cervical spine immobilization.
A three-dimensional, strain-gradient, crystal plasticity methodology is presented for prediction of microstructure-sensitive length-scale effects in crack initiation, under fatigue and fretting ...fatigue conditions, for a ferritic-pearlitic steel used in flexible marine risers. The methodology, comprising length-scale dependent constitutive model and scale-consistent fatigue indicator parameters, is calibrated and validated for representative (measured) dual-phase microstructures under strain-controlled low cycle fatigue conditions. Prediction of the effects of length-scale on fretting crack initiation is based on a three-dimensional, crystal plasticity, frictional contact model to predict fretting crack location and initial growth path, accounting for the effects of crystallographic orientation. The length-scale dependent fatigue and fretting simulations predict (i) significant beneficial effect of reducing length-scale for low cycle fatigue life, (ii) complex cyclically- and spatially-varying effects and differences due to changing contact and grain length-scales, and (ii) that fretting damage generally decreases with decreasing (contact-grain) length-scale.
Statistical detection methods are routinely used to automate auditory evoked response (AER) detection and assist clinicians with AER measurements. However, many of these methods are built around ...statistical assumptions that can be violated for AER data, potentially resulting in reduced or unpredictable test performances. This study explores a frequency domain bootstrap (FDB) and some FDB modifications to preserve test performance in serially correlated non-stationary data.
The FDB aims to generate many surrogate recordings, all with similar serial correlation as the original recording being analysed. Analysing the surrogates with the detection method then gives a distribution of values that can be used for inference. A potential limitation of the conventional FDB is the assumption of stationary data with a smooth power spectral density (PSD) function, which is addressed through two modifications.
The FDB was compared to a conventional parametric approach and two modified FDB approaches that aim to account for heteroskedasticity and non-smooth PSD functions. Hotelling’s T2 (HT2) test applied to auditory brainstem responses was the test case.
When using conventional HT2, false-positive rates deviated significantly from the nominal alpha-levels due to serial correlation. The false-positive rates of the modified FDB were consistently closer to the nominal alpha-levels, especially when data was strongly heteroskedastic or the underlying PSD function was not smooth due to e.g. power lines noise.
The FDB and its modifications provide accurate, recording-dependent approximations of null distributions, and an improved control of false-positive rates relative to parametric inference for auditory brainstem response detection.
•The frequency domain bootstrap (FDB) is introduced to ABR detection.•FDB modifications are proposed to account for heteroskedasticity and non-smooth PSDs.•The FDB and modified FDB approaches outperform parametric response detection methods.
The ABCDE bundle incorporates multidisciplinary measures to improve and/or preserve patients' physical, functional, and neurocognitive status through awakening and breathing coordination, delirium ...prevention and management, and early physical mobility.
To quantify the prevalence and duration of delirium in patients in the intensive care unit (ICU) before and after implementation of the ABCDE bundle.
Delirium prevalence was defined as the percentage of patients who had at least 1 positive delirium score on the Intensive Care Delirium Screening Checklist (ICDSC) during the ICU stay; delirium duration was the number of days during the ICU stay that a positive ICDSC score was noted. Retrospective data were collected from before and after implementation of the ABCDE bundle.
Of the 159 records reviewed (80 before and 79 after bundle implementation), most were for white men (mean age, 66.3 years). After implementation of the ABCDE bundle, the prevalence of delirium decreased significantly (from 38% to 23%, P = .01) and the mean number of days of delirium decreased significantly (from 3.8 to 1.72 days, P < .001). The number of patients with delirium-free stays increased after bundle implementation.
Implementation of the ABCDE bundle led to significant decreases in the prevalence and duration of delirium in ICU patients.
The Pentax Airwayscope®, the Glidescope®, and the Truview EVO2® constitute three novel laryngoscopes that facilitate visualization of the vocal cords without alignment of the oral, pharyngeal, and ...tracheal axes. We compared these devices with the Macintosh laryngoscope in a simulated easy and difficult laryngoscopy.
Thirty-five experienced anaesthetists were allowed up to three attempts to intubate in each of four laryngoscopy scenarios in a Laerdal® SimMan® manikin. The time required to perform tracheal intubation, the success rate, number of intubation attempts and of optimization manoeuvres, and the severity of dental compression were recorded.
In the simulated easy laryngoscopy scenarios, there was no difference between the study devices and the Macintosh in success of tracheal intubation. In more difficult tracheal intubation scenarios, the Glidescope® and Pentax AWS®, and to a lesser extent the Truview EVO2® laryngoscope demonstrated advantages over the Macintosh laryngoscope including a better view of the glottis, greater success of tracheal intubation, and ease of device use. The Pentax AWS® was more successful in achieving tracheal intubation, required less time to successfully perform tracheal intubation, caused less dental trauma, and was considered by the anaesthetists to be easier to use.
The Pentax AWS® laryngoscope demonstrated more advantages over the Macintosh laryngoscope than either the Truview EVO2® or the Glidescope® laryngoscope, when used by experienced anaesthetists in difficult tracheal intubation scenarios.
In this paper, a global-local fretting design methodology for the pressure armour layer of flexible marine risers is outlined. This includes global dynamic riser analysis, geometrical and analytical ...sub-models and local nub-groove contact finite element analysis. Furthermore, a fretting test rig is developed and utilised to quantify coefficient of friction and wear coefficient under representative nub-groove loading conditions. The combination of the global-local computational methodology and experimental characterisation of pressure armour wire material allows for the development of running condition fretting maps. This identifies design criteria for critical riser global curvatures that are associated with minimum number of cycles to failure. The design methodology presented in this paper is applied to a realistic riser design study, using extreme sea-state loading conditions. In this case study, the predicted pressure armour fretting fatigue lives are found to be in the same range as the plain fatigue lives of the tensile armour layer.
•Global-local fretting design methodology for the pressure armour layer of flexible marine risers.•Global dynamic riser analysis, geometrical and analytical sub-models and local nub-groove contact finite element analysis.•Development and utilisation of a fretting rig to quantify friction and wear coefficients under representative nub-groove loading conditions.•Identification of design criteria for critical riser global curvatures associated with minimum number of cycles to failure.•Realistic riser design study, using extreme sea-state loading conditions.
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