High Inflation Pressure Research Articles

G Protection When Adding Pressurized Sleeves and Gloves to a Representative G-Suit Ensemble

In a previous study, pressurized sleeves and gloves were found to substantially diminish or eliminate G-induced arm pain. Since this equipment presumably acts similarly to a G suit for the arms and hands, it was hypothesized that higher inflation pressures might provide an additional increment of G protection. In a human-rated centrifuge, 15 well trained subjects using Combat Edge and ATAGS G-protective equipment were exposed to gradual and rapid onset relaxed G exposures as well as rapid onset straining and simulated aerial combat maneuver G exposures up to + 9 Gz with and without pressurized sleeves and gloves. The pressurized sleeves and gloves did not show any improvement in G tolerance or endurance compared to the control. However, significantly lower heart rates (6-12%) and subjective effort (11%), along with slightly less peripheral vision loss, suggest a decreased work load when wearing the pressurized sleeves and gloves. A trend to shorter time on target in a tracking task was found with the pressurized sleeves and gloves, likely due to decreased mobility of the hands, thus affecting control stick input. G tolerance and endurance were not improved by the pressurized sleeves and gloves. However, a lower heart rate and a decreased subjective effort level and peripheral vision loss indicated that the subjects did not have to work as hard with this equipment.

Analysis of Human Vastus Lateralis Skeletal Muscle Biopsy Samples Changes in Response to High and Low Inflation Pressures during Peristaltic Pulse External Pneumatic Compression Via Transcriptome‐wide RNA Sequencing

We employed next generation RNA sequencing (RNA‐seq) technology to determine the impact of peristaltic pulse external pneumatic compression (EPC) at high and low target inflation pressures on global gene expression in human vastus lateralis skeletal muscle biopsy samples.MethodsEighteen (N=18) apparently healthy male subjects participated in this study and were randomly assigned to one of three groups: 1) sham (n=6), 2) EPC with target inflation pressures of 30 mmHg (n=6) and 3) EPC with target inflation pressures of 70–80 mmHg (n=6). Daily treatment with sham or EPC was given for 7 consecutive days with each treatment lasting 1 h. Vastus lateralis skeletal muscle biopsy samples were harvested at baseline (48 hours before the first treatment; T1), 1 h following the first treatment (T2), and 24 hours following the last (7th) treatment (T3). 3,613 annotated genes with an RPKM value of ≥ 1.0 were selected for analysis. Change from baseline (T1) in gene expression was analyzed via paired comparisons within each group (i.e. T2 vs. T1 and T3 vs. T1). The 3,613 genes were then further filtered to include only those that had a fold‐change (FC) of ≥ 1.5 and a paired t‐test value of <0.01.ResultsFor the sham condition, only 2 genes at T2 (SF3B5, FIS1) and 1 gene at T1 (LYPLA2) were identified as being significantly altered compared to baseline with time. For the 30 mmHg EPC condition, 9 genes were found to be significantly upregulated at T2 and 39 genes were found to be significantly upregulated at T3 compared to baseline. Two of these genes were significantly upregulated at both T2 and T3 (ARRDC2 and DYNLL2). Only one gene was found to be significantly downregulated compared to baseline in the 30 mmHg EPC group (TIMM10) and this was observed at T3. For the 70–80 mmHg EPC condition, 2 genes were found to be significantly upregulated (HBA1, HBA2) and 21 genes were found to be significantly downregulated at T2 compared to baseline. At T3, only 1 gene was found to be significantly altered (downregulation of DNAJB5) in the 70–80 mmHg EPC group. Interestingly, VEGFA was found to be differentially regulated as its expression was significantly upregulated with 30 mmHg EPC at T3 and significantly downregulated with 70–80 mmHg EPC at T3. Follow up analyses respective to gene clusters of interest are presented herein.ConclusionsIn summary, a more dynamic alteration of skeletal muscle gene expression was observed with a lower (i.e. 30 mmHg) EPC target inflation pressure, particularly after 7 consecutive days of treatment. Moreover, altered genes tended to be upregulated with 30 mmHg EPC whereas genes tended to be downregulated with 70 mmHg.Support or Funding InformationThe authors would like to thank NormaTec (Newton Center, MA) for their partial financial support (50%) of this project through a contract awarded to J.S.M.

Pavement Response to Variable Tyre Pressure of Heavy Vehicles

In recent years, the effect of overinflated tyre pressure and increased heavy vehicles’ axle load on flexible pavements has become a subject of great concern because of the higher stress levels induced and damage caused to road pavements. This paper aims to evaluate the effect of variable tyre inflation pressures (using actual tyre contact/footprint area) to determine the responses of flexible pavement. A full scale experiment was conducted on a heavy vehicle with 1:1:2 axle configuration, 10 R 20 tyre size and attached trailer with constant axle load. Measurements were made for actual tyre-pavement contact area. KENPAVE linear elastic program was then used to analyse the effects of the measured actual tyre-pavement contact area and the results was compared using conventional circular tyre contact area. A comparative analysis was then made between the actual contact area and the conventional circular tyre contact area. It was found that high tyre inflation pressure produce smaller contact area, giving more detrimental effect on the flexible pavement. It was also found that the temperature of tyres when the heavy vehicles are operational give less significant impact on tyre inflation pressure for the Malaysian climate.

Modelling in FEM the soil pressures distribution caused by a tyre on a Rhodic Ferralsol soil

Tyre traffic over soil causes non-uniform ground pressures across the tyre width and along the soil–tyre contact area. The objective of this paper was to obtain in the topsoil the shape, magnitudes, distribution and transmission in depth of the ground pressures from a finite element model of soil compaction. The influence of tyre inflation pressure, tyre load and soil water content over the pressures propagation in the soil was analysed. The model shows how to low inflation pressure the tyre carcass supports most of the total load and the biggest peak pressures are distributed in the tyre axes when it traffics over firm soil. For high inflation pressure the incremented stiff causes that pressure is distributed with parabolic shape. In wet soil the inflation pressure does not influence on the ground pressure distribution, this depends only on the tyre load. The inflation pressure and tyre load changed the shape of the vertical pressures distribution on the surface of a hard dry soil, but these variables did not affect the distribution of vertical stresses in a soft wet soil or below a depth of 0.15m.

Mechanical ventilation after lung transplantation

IntroductionTo explore the hypothesis that early ventilation strategies influence clinical outcomes in lung transplantation, we have examined our routine ventilation practices in terms of tidal volumes (Vt) and inflation pressures. MethodsA total of 124 bilateral lung transplants between 2010 and 2013 were retrospectively assigned to low (<6 mL/kg), medium (6-8 mL/kg), and high (>8 mL/kg) Vt groups based on ventilation characteristics during the first 6 hours after surgery. Those same 124 patients were also stratified to low-pressure (<25 cm H2O) and high-pressure (≥25 cm H2O) groups. ResultsEighty percent of patients were ventilated using pressure control mode. Low, medium, and high Vt were applied to 10%, 43%, and 47% of patients, respectively. After correcting for patients requiring extracorporeal support, there was no difference in short-term to midterm outcomes among the different Vt groups. Low inflation pressures were applied to 61% of patients, who had a shorter length of intensive care unit stay (5 vs 12 days; P = .012), higher forced expiratory volume in 1 second at 3 months (77.8% vs 60.3%; P < .001), and increased 6-month survival rate (95% vs 77%; P = .008). ConclusionLow Vt ventilation has not been fully adopted in our practice. Ventilation with higher inflation pressures, but not Vt, was significantly associated with poorer outcomes after lung transplantation.

Optimization of stent implantation using a high pressure inflation protocol.

High-pressure inflation is the universal standard for stent deployment but a specific protocol for its use is lacking. We developed a standardized "pressure optimization protocol" (POP) using time to inflation pressure stability as an endpoint for determining the required duration of stent inflation. The primary study purpose was to determine the stent inflation time (IT) in a large patient cohort using the standardized inflation protocol, to correlate various patient and lesion characteristics with IT, and ascertain in an in vitro study the time for pressure accommodation within an inflation system. Six hundred fifteen stent implants in 435 patients were studied. Multivariate analysis was performed to determine predictors of longer ITs. In an in vitro study, various stents and balloons were inflated in air to determine the pressure accommodation time of the inflation system. The mean stent IT was 104 ± 41 sec (range 30-380 sec). Stent length was the only predictor of prolonged stent inflation. The "accommodation time" in vitro of the stent inflation system itself was 33 ± 24 sec. The protocol was safe requiring premature inflation termination in <3% of stent implants. No serious adverse events occurred. Achieving stable inflation pressure requires on average over 100 sec and may require several minutes in individual cases. Stent length increases IT. These results suggest that the widespread practice of rapid inflation/deflation may not be sufficient to fully expand the stent and that the use of a pressure stability protocol will allow for safe, predictable, and more complete stent deployment. © 2015 Wiley Periodicals, Inc.

致死性窒息の小児症例に体外式膜型人工肺が有効であった1例(Extracorporeal membrane oxygenation used for cardiopulmonary support in a case of pediatric problematic airway obstruction)

要旨風船による気管異物は頻度は低いが，乳幼児における食物以外の窒息死の原因となり得る。我々は，風船による致死性窒息に対し体外式膜型人工肺（ECMO）を導入することで救命し得た症例を経験した。症例は生来健康な1歳の女児。子供同士で遊んでいて風船を飲み込み，呼吸窮迫となったため当救命救急センターに救急搬送された。来院時，意識レベルJCS 300，あえぎ呼吸でバッグバルブマスクによる換気はできず，SpO2測定は不能だった。直ちに挿管を施行し，SpO2 100％となり自発運動を認めた。経口挿管チューブから細径軟性気管支鏡を施行するも，気道分泌物が多く異物は同定できなかった。挿管チューブの位置修正後に換気が再び困難となり，酸素化も保てなかったため緊急でECMOを導入した。3D構築したCT画像で気管から右主気管支にかけて嵌頓する異物を認めた。ECMOの導入により呼吸・循環の安定化を図ったのち，一旦気管チューブを抜管し，軟性気管支鏡下に約4cm，幅約0.8cmのゴム風船を除去した。無気肺と陰圧性肺水腫のため4日間のECMO管理を要した。第18病日に人工呼吸器を離脱，第39病日に自宅退院となった。気管異物による小児の致死性窒息に対してECMOを導入した報告は少ない。本症例のように重篤な呼吸不全を伴う乳幼児の気管異物では，異物除去の際にECMOによる補助が有用であると考えられた。

Balloon catheters with integrated stretchable electronics for electrical stimulation, ablation and blood flow monitoring

Balloon catheter-based techniques that apply mechanical force to blood vessel walls have dramatically advanced the standard of care for patients with vascular disease. But balloons are limited in their therapeutic potential because they rely on mechanics alone and lack electronically active materials. Recent advances in balloon catheters with integrated electrodes have offered additional treatment capabilities through the application of both mechanical contact force and radio frequency electromotive force. However, these smart balloons remain limited in their mechanics and their ability to provide diagnostic information about local vessel hemodynamics and tissue health near treatment zones. Here, we demonstrate a novel instrumented balloon catheter system that contains stretchable electrodes and thermal-based blood flow sensors, providing hemodynamic information, electrical stimulation, and ablation therapy on a single device. This system accommodates high inflation pressure (∼2 atm) and twisting and bending over a broad range of vascular diameters and geometries. Finite element and analytical modeling capture the anisotropic mechanical and thermal properties of the device during cycles of inflation and deflation in a simulated biological environment. Bench-top ablation and in vivo blood flow measurements highlight the utility of this technology for clinical application.

Absorb everolimus-eluting bioresorbable scaffolds in coronary bifurcations: a bench study of deployment, side branch dilatation and post-dilatation strategies.

To provide bench insights which may predict safety and efficacy of side branch dilatation (SB) and kissing balloon post-dilatation (KBPD) in Absorb everolimus-eluting bioresorbable scaffolds deployed in bifurcations. Stages of deployment and post-dilatation of scaffolds (3.0 and 3.5 mm diameter) in bifurcation phantoms were imaged by fluoroscopy, light microscopy and micro-computed tomography. Dilatation through the scaffold side displaced struts from the side branch (SB) lumen, but caused main branch (MB) malapposition opposite the SB, MB scaffold narrowing beyond the SB, and protrusion of struts into the SB. Scaffold distortion was corrected by MB post-dilatation or by mini-kissing balloon post-dilatation (mini-KBPD). When 3.0 mm diameter balloons were used for SB dilatation or mini-KBPD in 3.0 mm Absorbs, strut fracture did not occur at or below inflation pressures of 10 and 5 atm, respectively. Above these thresholds, the likelihood of strut fracture increased with increasing pressure. Fractures were usually single without malapposition, but mini-KBPD or post-dilatation with high inflation pressures sometimes caused multiple strut fractures and lumen compromise. SB dilatation of an Absorb caused MB distortion which was corrected by MB post-dilation or low-pressure mini-KBPD without scaffold damage below pressure thresholds. These benchtop insights may help guide the clinical deployment of Absorb scaffolds in bifurcations and might enhance clinical outcomes but need clinical confirmation.

English

BACKGROUND: Airway management plays a key role in day to day anesthesia practice. But unanticipated difficult airway and unnecessary pressor response to laryngoscopy and intubation remains a challenge to the anesthesiologist. A continuous effort has been made to develop new methods and tools to facilitate endotracheal intubation and minimize pressor response. One such device was Laryngeal Mask Airway (LMA). However, the use of LMA was associated with problems like gastric insufflation, pulmonary aspiration, inadequate ventilation and the inability to generate high inflation pressures in bronchospastic patients. Hence ILMA was introduced as an alternative. METHODS: In this prospective study, the feasibility of Intubating Laryngeal Mask Airway (ILMA) insertion and blind endotracheal intubation through ILMA was done in 100 patients undergoing various elective surgeries under general anesthesia. Only ASA Grade I and II patients with normal airway (Mallampati Class I and II) were selected. After administering conventional general anaesthesia, ILMA was inserted as per the standard technique. Blind endotracheal intubation was done through ILMA. Time required for insertion of ILMA, number of attempts required, time duration to achieve intubation and number of attempts for blind endotracheal intubation were recorded. RESULTS: Our study showed that ILMA was inserted successfully in all patients, 91% required one attempt and 9% required 2 attempts. The mean time duration for successful ILMA placement was 33.47 secs. Blind endotracheal intubation through ILMA was possible in 97% of patients, 75% required 1 attempt, 18% required 2 attempts and 4% required 3 attempts. The mean time duration for blind endotracheal tube insertion was 21.74+6.98 secs. CONCLUSION: Thus from our study it can be concluded that ILMA can be used as a blind intubation guide with a higher success rate.

Characterization of acute ischemia-related physiological responses associated with remote ischemic preconditioning: a randomized controlled, crossover human study.

Remote Ischemic Preconditioning (RIPC) is emerging as a new noninvasive intervention that has the potential to protect a number of organs against ischemia–reperfusion (IR) injury. The standard protocols normally used to deliver RIPC involve a number of cycles of inflation of a blood pressure (BP) cuff on the arm and/or leg to an inflation pressure of 200 mmHg followed by cuff deflation for a short period of time. There is little evidence to support what limb (upper or lower) or cuff inflation pressures are most effective to deliver this intervention without causing undue discomfort/pain in nonanesthetized humans. In this preliminary study, a dose–response assessment was performed using a range of cuff inflation pressures (140, 160, and 180 mmHg) to induce limb ischemia in upper and lower limbs. Physiological changes in the occluded limb and any pain/discomfort associated with RIPC with each cuff inflation pressure were determined. Results showed that ischemia can be induced in the upper limb at much lower cuff inflation pressures compared with the standard 200 mmHg pressure generally used for RIPC, provided the cuff inflation pressure is ~30 mmHg higher than the resting systolic BP. In the lower limb, a higher inflation pressure, (~55 mmHg > resting systolic BP), is required to induce ischemia. Cyclical changes in capillary blood O2, CO2, and lactate levels during the RIPC stimulus were observed. RIPC at higher cuff inflation pressures of 160 and 180 mmHg was better tolerated in the upper limb. In summary, limb ischemia for RIPC can be more easily induced at lower pressures and is much better tolerated in the upper limb in young healthy individuals. However, whether benefits of RIPC can also be derived with protocols delivered to the upper limb using lower cuff inflation pressures and with lesser discomfort compared to the lower limb, remains to be investigated.

Identification of the characteristics of motorcycle and scooter tyres in the presence of large variations in inflation pressure

Stability and safety of road vehicles are largely affected by tyre properties. Single-track vehicles are characterised by weakly damped modes of vibration (weave and wobble) and therefore this phenomenon is even more important. This article focuses on the study of both steady-state and transient properties of motorcycle and scooter tyres in the presence of very low and very high inflation pressures. The steady-state properties are defined as lateral forces (side-slip and camber forces) and yaw torques (self-aligning and twisting). The transient properties are described in terms of relaxation length, which represents the distance needed to reach a certain percentage of the steady-state value of the tyre force. Experimental tests are carried out on a specific rotating disk machine. Three sets of tyres are analysed. Steady-state properties are measured by increasing step by step the values of camber and side-slip angles. Transient properties are studied carrying out tests with harmonic side-slip excitation and measuring the phase lag between the excitation (input) and the tyre force (output). Experimental results show important variations in tyre properties with inflation pressure with general trends of all the tested tyres and particular features related to the tyre's geometry. After the analysis and discussion of experimental results, the measured data are fitted by means of a specific version of the Magic Formula. The dependence of the Magic Formula's coefficients on inflation pressure is analysed and interpolation curves are given.

Is an i-gel® supraglottic airway useful for airway rescue in the community?

Objective: To ascertain whether an i-gel® (Intersurgical UK) supraglottic airway is suitable for newborn resuscitation in the community. Method: Fifty five community midwives were invited to participate in this study during their continuing professional development (CPD) training time over a 4 month period. Twenty of the midwives were able to participate during this time frame. The midwives were asked to manage a newborn resuscitation scenarios using 2 differing techniques: Bag valve mask with a Guedel airway (control) and a bag with an i-gel®. Results: Time to first breath was quicker using the i-gel® compared to bag valve mask and Guedel airway. There was no significant difference in duration of inflation breaths between the two techniques. Participants generated higher inflation pressures using i-gel® with a mean of 40cm H2O as opposed to 34cm H2O with the bag valve mask and Guedel airway. Conclusion: The time to first breath is considerably shorter using an i-gel® although airway pressures were significantly higher. Further investigation is needed before it could be recommended for clinical use, specifically to investigate the increased airway pressures and the true rate of failure.

Is Money Supply the Cause of Inflation in India? An Alternative Postulate to Understand Inflation

‘Inflation is always a monetary phenomenon’ say some economists and policymakers and attempt to arrest rising inflation with policies aimed at reducing the money supply in the economy. The theory is true in countries which have reached the full employment level, but in developing and underdeveloped countries this may not always be true. Advanced countries facing severe recession try to bring about inflation by raising money supply, and other advanced countries with high inflation pressure are able to successfully curtail inflation by reducing money supply. However, the entire inflation dynamics playing out in developing economies are different and it's necessary to re-visit and re-examine the relevance of the belief that inflation is always a monetary phenomenon, especially with respect to developing economies. The present research paper attempts to test the validity of the quantity theory of money in Indian situation and provide an alternative postulate.

How driving wheels of front-loaded tractor interact with the terrain depending on tire pressures

This paper analyzes peculiarities of wheel interaction with the terrain for 4WD tractors working with front-mounted loaders. When tractor wheels are loaded by a vertical forces that do not correspond to the specified proportions, deformations of front and rear tires also do not correspond to the specified proportions, and this leads to a kinematic discrepancy because of change in ratio between driving wheels’ rolling radiuses. In case of kinematic discrepancy, wheel slip/skid is taking place. In the paper test results are presented, how driving wheels’ slip/skid of 4WD tractors with front-mounted loaders depend on the vertical loads acting on the wheels and their tire inflation pressures. It was determined that there are dependences on relation between front and rear tire pressures, which allow avoiding wheel slip/skid for the 4WD tractor with front-mounted loader that runs without a load and transports loads. By preparing a tractor for work with front-mounted loader, it is advisable for operator to select a set of tires that would ensure the lead of front wheels lesser compared to the lead that is commonly used for traction works. In this case, the operator creates conditions for wheels’ interaction with the terrain without slip/skid at higher inflation pressures in the front tires.

Acute changes of left ventricular hemodynamics and function during percutaneous coronary intervention in patients with unprotected left main coronary artery disease

Percutaneous coronary interventions (PCIs) are increasingly being used to treat unprotected left main coronary artery (ULMCA) lesions. However, research is sparse on the acute changes of left ventricular (LV) hemodynamics and function during PCI in patients with ULMCA stenosis. We aimed to assess the acute changes of LV function using speckle-tracking imaging during PCI in these patients. Fifteen consecutive patients who underwent elective PCI for ULMCA stenosis were enrolled. Echocardiographic studies and pressure measurement were performed at baseline, during PCI and after PCI. LMCA occlusion with a first balloon inflation induced a marked reduction in the peak positive derivative of LV pressure (dP/dt max), LV global longitudinal strain (GLS), and systolic and diastolic strain rates, and a marked increase in LV end-diastolic pressure (EDP) (all P<0.01). During the second inflation, the degrees of LV hemodynamic and functional changes were similar to those of the first inflation, even with a higher inflation pressure. During the third inflation, the values of GLS and dP/dt max were higher than those of the second inflation (P=0.03 and P=0.05, respectively). After optimal PCI, dP/dt max, LVEDP, and strain parameters were improved to baseline values. LV hemodynamics and function were considerably impaired with the first ballooning during PCI for ULMCA stenosis. However, the degrees of LV hemodynamic and functional changes decreased with each successive balloon inflation, which can be explained by ischemic preconditioning. After all procedures were safely completed, LV systolic function was improved without LV diastolic stunning.

Reducing crop damage and yield loss in late harvests of Miscanthus × giganteus

Unfavourable weather conditions can delay the harvest of Miscanthus in Ireland until April and new shoots may have emerged when the crop is trafficked. Poor crop regrowth has been observed in these circumstances corresponding with the location of vehicle wheelings. In an attempt to find a solution to this problem, a field experiment was conducted in 2009 in which the stubble of a mature Miscanthus crop, containing newly emerged shoots, was trafficked with heavy axle loads, simulating harvest equipment. Three treatments were used including (a) an untrafficked control, (b) trafficking with equipment adjusted to reduced tyre inflation pressure (RP) and (c) trafficking with equipment adjusted to high tyre inflation pressure (HP). The effects of this one-time trafficking event on crop response were determined by measuring stem numbers, stem height, biomass yield and overall stem yield in 2009, 2010 and 2011. Effects on soil compaction were determined by measuring soil penetration resistance (SPR), bulk density (BD), water infiltration rate (IR) and air-filled porosity (AFP). Traffic damage reduced stem numbers and overall stem yield in the growing season immediately following the traffic event and also in subsequent years, implying that the negative impacts of this one-time traffic event were prevalent for at least a number of years after trafficking. In the three years of monitoring, trafficked zone stem numbers and biomass yield were significantly higher (49.4 and 76.6% respectively) in the RP treatment when compared to the HP treatment as was the overall stem yield (16.9% higher) but there was no significant difference between the RP treatment and the control. Values for SPR and BD were very high in all treatments; however, IR and AFP were substantially higher in the RP treatment and control when compared to the HP treatment. Harvesting Miscanthus post shoot emergence using high tyre inflation pressure caused significant crop damage and yield loss which can be minimised by using reduced tyre inflation pressure on harvest machinery.

Relationship Between Intravascular Ultrasound Guidance and Clinical Outcomes After Drug-Eluting Stents

Background— Prior small to modest-sized studies suggest a benefit of intravascular ultrasound (IVUS) guidance in noncomplex lesions. Whether IVUS guidance is associated with improved clinical outcomes after drug-eluting stent (DES) implantation in an unrestricted patient population is unknown. Methods and Results— Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter, nonrandomized “all-comers” study of 8583 consecutive patients at 11 international centers designed to determine the frequency, timing, and correlates of stent thrombosis and adverse clinical events after DES. Propensity-adjusted multivariable analysis was performed to examine the relationship between IVUS guidance and 1-year outcomes. IVUS was utilized in 3349 patients (39%), and larger-diameter devices, longer stents, and/or higher inflation pressures were used in 74% of IVUS-guided cases. IVUS guidance compared with angiography guidance was associated with reduced 1-year rates of definite/probable stent thrombosis (0.6% [18 events] versus 1.0% [53 events]; adjusted hazard radio, 0.40; 95% confidence interval, 0.21–0.73; P =0.003), myocardial infarction (2.5% versus 3.7%; adjusted hazard radio, 0.66; 95% confidence interval, 0.49–0.88; P =0.004), and composite adjudicated major adverse cardiac events (ie, cardiac death, myocardial infarction, or stent thrombosis) (3.1% versus 4.7%; adjusted hazard radio, 0.70; 95% confidence interval, 0.55–0.88; P =0.002). The benefits of IVUS were especially evident in patients with acute coronary syndromes and complex lesions, although significant reductions in major adverse cardiac events were present in all patient subgroups those with including stable angina and single-vessel disease. Conclusions— In ADAPT-DES, the largest study of IVUS use to date, IVUS guidance was associated with a reduction in stent thrombosis, myocardial infarction, and major adverse cardiac events within 1 year after DES implantation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov . Unique identifier: NCT00638794.

Development of adaptive pneumatic tourniquet systems based on minimal inflation pressure for upper limb surgeries

BackgroundPneumatic tourniquets are medical devices that occlude blood flow to distal part of extremities and are commonly used in upper limb surgeries to provide a dry, clean and bloodless field. To decrease pressure-related injuries and potential risk of complications subjected to the high inflation pressure of pneumatic tourniquet, minimal inflation pressures are recommended.MethodsA new occlusion pressure mathematical model for the upper limb was established based on the correlation analysis between several possible influencing parameters and the minimal pneumatic tourniquet pressure at which the peripheral pulse disappeared was recorded using a digital plethysmograph. A prototype of an adaptive pneumatic tourniquet which automatically varies the pressure in the tourniquet cuff according to the above prediction model was developed for the upper limb which used the lowest possible inflation pressure to achieve occlusion. The prototype comprises a blood pressure monitoring module, an inflatable tourniquet cuff, and a pressure relief mechanism to maintain an optimal cuff inflation pressure. Simulation experiments were conducted to verify the function and stability of the designed adaptive pneumatic tourniquet and clinical experiments using volunteers were undertaken to evaluate the performance of the prototype design in achieving adequate haemostasis in the upper limb.ResultsResults demonstrated that the mean arterial occlusion pressure was 152.3 ± 16.7 mmHg, obviously below the 250 to 300 mmHg previously recommended (J Bone Joint Surg Br 68:625-628, 1986 and Arthroscopy 11:307–311, 1995).ConclusionsIn conclusion, this adaptive method and apparatus which can provide minimal inflation pressure may be a clinically practical alternative for upper limb surgery performed with pneumatic tourniquets.

Excimer laser in management of underexpansion of a newly deployed coronary stent

We report the successful management of underexpansion of a newly deployed coronary stent refractory to balloon dilatations. Direct stenting was performed for a lesion in the mid left anterior descending artery (without angiographically apparent heavy coronary calcification). The stent remained underexpanded despite repeated balloon dilatations including with high-pressure inflations. Subsequently, an excimer laser catheter was used in an attempt to vaporize the plaque by the accoustomechanical effect of the rapidly exploding bubbles. The overall angiographic result was good after further balloon dilatation with ordinary pressure and full stent expansion was achieved. Management of underexpansion of a newly deployed stent is a potential indication of laser angioplasty.