Alarm Fatigue among Nurses Working in Critical Care Setting in a Tertiary Hospital, Nepal.

Background Alarm fatigue is a well-recognized patient safety concern in critical care settings. It occurs when nurses become overwhelmed by the total number of alarm signals which can result in alarm desensitization and eventually contributes to missing of serious and important changes in a patient's condition, thus failing to respond properly. Objective To find out alarm fatigue and its associated factors among nurses working in critical care setting. Method A cross-sectional study design with convenient sampling technique was used to select 56 nurses working at different critical care settings in Dhulikhel Hospital. A selfconstructed semi structured questionnaire and nurses alarm fatigue questionnaire was used for the survey. Frequency, percentage, mean and standard deviation were used for descriptive statistics whereas Independent t-test and One-way ANOVA were used for inferential statistics. Result The result shows that more than half of the nurses were less than 25 years, single and more than two-third of the participants worked in Adult Intensive Care Unit. Out of total obtainable score 44, the overall mean score of the Alarm Fatigue was 28.03±12.813. The result showed that there was no significant difference between alarm fatigue and selected socio-demographic and work related characteristics. Conclusion The alarm fatigue among nurses working in critical care settings was found to be higher in this study. Since alarm fatigue is directly related to patients' safety, the effective management of medical device alarms can reduce alarm fatigue and prevent potentially dangerous outcomes.

Round Block Technique in Management of Breast Lesions.

The basic tenets of oncoplastic surgery essentially includes volume displacement and volume replacement. The round block technique, so-called donut mastopexy or Benelli mastopexy, is frequently used as a volume displacement technique in breast conserving surgery for benign multicentric fibroadenomas and early breast cancers. Such techniques are still underused in Nepal. In this article we present on four cases managed with original round block technique and followed prospectively with their outcome.

Self-Perception of Halitosis among Undergraduate Students of Kathmandu University School of Medical Sciences - A Questionnaire Based Study.

Background Halitosis is a frequently reported oral health problem worldwide with a prevalence rate of 10-30% in the general population. It is defined as the disagreeable or foul smelling breath originating consistently from a person's oral cavity. It not only effects the normal daily life activities of the patient but also bring humiliation, reduced self- esteem, ultimately resulting into decreased quality of life. Objective To determine the self-perception of halitosis among undergraduate students of different medical branches of Kathmandu University School of Medical Sciences (KUSMS); Kavre, Nepal. Method A descriptive cross-sectional epidemiological survey was conducted among undergraduate students of Physiotherapy, B.Sc Nursing, Bachelor of Nursing Sciences (BNS), MBBS and BDS program of Kathmandu University School of Medical Sciences, Dhulikhel. A self-administered questionnaire was developed and were distributed among 500 undergraduate students. Result Out of total 500 distributed questionnaires, 406 were completely filled and returned giving an overall response of 81.2%, in which 70 (89.7%) male and 280 (85.4%) female students from different medical branches were aware of the term halitosis. Among them 29 (7.14%) of students think that they suffer from halitosis. Similarly 178 (43.84%) students had severe impact of halitosis on their social life while 153 (37.68%) and 62 (15.27%) students had moderate and mild impact respectively. Conclusion Due to the multifactorial complexity of halitosis, further longitudinal studies including objective assessment of malodor are required to determine its prevalence and to further investigate the association of this problem with other etiological factors in the context of Nepal. Also, curriculum of different fields should be modified to include this simple but very necessary topic.

Extended Spectrum ß-lactamase (ESBL) Producing Multi Drug Resistant (MDR) Urinary Pathogens in a Children Hospital from Nepal.

Background Multidrug resistant in clinical bacterial isolates has increasingly been reported through out the world and is associated with high morbidity, mortality and increased health care costs. It is important to determine the status of multidrug resistance pattern to understand the current resistance trend so that appropriate antibiotics can be used in practice. Objective To determine the antibiotic resistant profile and prevalence of extended spectrum ß-lactamase producing multidrug resistant strains in pediatric patients of Kanti Children's Hospital, Kathmandu, Nepal. Method Urine sample was cultured by standard microbiological techniques and bacterial isolates were identified using different biochemical tests. Antibiotic susceptibility testing was performed by Kirby Bauer disc diffusion method and extended spectrum ß-lactamase detection was carried out using combined disc method as recommended by Clinical Laboratory Standard Institute guidelines. Result All together 65 different bacteria were isolated and subsequently identified. E. coli was the most common isolate with 46 (71%) isolates 63% of these isolates were multidrug resistant. Gram negative isolates were most resistant to nalidixic acid (81.97%) followed by ampicillin (69.35%) and co-trimoxazole (69.35%). The extended spectrum ß-lactamase producing isolates were 43% among total isolates. Conclusion Higher rate of Extended Spectrum ß-lactamase production among multidrug resistant isolates suggested routine extended spectrum ß-lactamase testing in clinical isolates.

Epidemiology of Work-Related Musculoskeletal Symptoms and Illnesses among Brick Kiln Workers in Kathmandu Valley, Nepal.

Background Workers in the brick manufacturing industries require to carry heavy loads, do repetitive work and remain in awkward postures for extended periods of time. These activities may cause them to develop work-related musculoskeletal symptoms and disorders. Objective To investigate the epidemiology of musculoskeletal symptoms and disorders among brick manufacturing workers as well as similar exposure groups among brick kiln workers. Method An analytical cross-sectional study was conducted during February - March 2015 in the Kathmandu Valley. From 16 brick kilns, 400 interviewees involving green brick molding, green brick stacking/carrying, red brick loading/carrying, coal crushing/ carrying and firing were recruited. An unmatched equal size of reference group of grocery workers was maintained for comparison. Prevalence of all musculoskeletal symptoms and disorders were computed and compared among brick workers and grocery workers as well as similar exposure groups among brick kiln workers. Result The musculoskeletal symptoms and disorders were prevalent in 90.5% of the exposed and 82.2% of the reference group. Brick kiln workers were about two times more likely to experience musculoskeletal symptoms and disorders compared to the reference group. When the associations among similar exposure groups were evaluated, there were significantly high prevalence of musculoskeletal symptoms and disorders among green brick molders, red brick loaders/carriers and coal crushers/ carriers in comparison to firemen. Conclusion This study showed a high prevalence of musculoskeletal symptoms and disorders among brick kilns workers. Among all similar exposure groups, coal crushing/carrying task significantly elevated with all types of musculoskeletal symptoms and disorders.

Airborne Particulate Matter and Health Condition in Brick Kiln Workers in Kathmandu Valley, Nepal.

Background Air quality monitoring in brick kilns indicates very high concentrations of airborne particulate matter. Air pollution from brick kilns poses an enhanced threat to the environment and to human health. Objective To evaluate airborne particulate matter concentration and health status of brick kiln workers. Method A cross-sectional comparative study was conducted in the Kathmandu valley targeting all brick industries and their workers during January - March 2015 and March - April 2016. A total of 16 brick kilns and 800 participants (400 brick workers as exposed and 400 grocery workers as referent) were selected for study. A direct-reading, Dusttrak model 8533 was used for air sampling. Nepali version questionnaire was applied to obtain epidemiological data. SPSS version 16 was used to perform statistical analysis. Median, mean, range and proportion were calculated and Mann-Whitney U test, Kruskal-Wallis test and chi square (c2) test were applied to test significance. Result Mean values of particulate matter concentrations for brickfields were as follows: Total Suspended Particulate Matter (TSPM): 5.179 mg/m3, PM10: 4.958 mg/m3, respirable suspended particulate matter (RSPM): 4.140 mg/m3, PM2.5: 3.965 mg/m3, and PM1: 3.954 mg/m3. The mean concentrations for grocery workers were; TSPM: 0.089 mg/ m3, PM10: 0.089 mg/m3, RSPM: 0.085 mg/m3, PM2.5: 0.082 mg/m3 and PM1: 0.082 mg/m3. Among brickfield workers, red and green brick loading zones had results that exceeded the ACGIH Threshold Limit Values for TSPM and RSPM. Workers complaints of injury were 52% and 44.2%, and illnesses were 88.5% and 82.2%, respectively among exposed and referent. The occurrence of injuries/illnesses during work showed significant association between exposed and the referent groups at 0.05 level. Conclusion The high level of airborne particulate matter in the brick fields requires action for the protection of workers. The availability of health services within brick industries needs to be enhanced.

Impact of a compulsory final year medical student curriculum on junior doctor prescribing.

BACKGROUND: Attendance at face-to-face sessions and completion of online components of the National Prescribing Curriculum was made compulsory for final year medical students at the University of Adelaide in 2010. AIMS: To determine the impact of a compulsory prescribing curriculum for final year medical students on their prescribing competencies at the start of clinical practice. Graduates' attitudes to their medical school training in prescribing were also surveyed. METHODS: Two cohorts of medical graduates from the University of Adelaide who commenced medical practice in 2010 and 2011 were required to complete a prescribing task using the National Inpatient Medication Chart (NIMC) at orientation and after 6 months of clinical practice. The main outcome measure was a performance in a scenario-based prescribing test, as determined by test scores and overall safety of prescriptions at orientation and 6 months of clinical practice. RESULTS: There was a small difference in the average total score for the prescribing task between the 2010 and 2011 cohorts at orientation (P = 0.0007). The 2011 cohort had a higher number of safer charts at commencement of practice. We found no difference between the 2010 and 2011 cohorts in attitudes towards their undergraduate pharmacology education, and new graduates feel poorly prepared. CONCLUSION: Medical graduates who are required to complete a practically oriented prescribing curriculum in final year perform slightly better on a prescribing assessment at commencement of practice. More work on preparing graduates for this complex task before graduation is needed.

Hyperthermia with magnetic nanowires for inactivating living cells.

We describe a method to induce hyperthermia in cells, in-vitro, by remotely heating Ni nanowires (NWs) with radio frequency (RF) electromagnetic fields. Ni NWs were internalized by human embryonic kidney cells (HEK-293). Only cells proximal to NWs or with internalized NWs changed shape on exposure to RF fields indicative of cell death. The cell death occurs as a result of hyperthermia, since the RF field remotely heats the NWs as a result of magnetic hysteresis. This is the first demonstration of hyperthermia induced by NWs; since the NWs have anisotropic and strong magnetic moments, our experiments suggest the possibility of performing hyperthermia at lower field strengths in order to minimize damage to untargeted cells in applications such as the treatment of cancer.

The miR-106b-25 cluster mediates breast tumor initiation through activation of NOTCH1 via direct repression of NEDD4L.

Tumor-initiating cells (TIC) represent a subset of tumor cells with increased self-renewal capability. TICs display resistance to frontline cancer treatment and retain the ability to repopulate a tumor after therapy, leading to cancer relapse. NOTCH signaling has been identified as an important driver of the TIC population, yet mechanisms governing regulation of this pathway in cancer remain to be fully elucidated. Here we identify a novel mechanism of NOTCH regulation and TIC induction in breast cancer via the miR-106b-25 miRNA cluster. We show that the miR-106b-25 cluster upregulates NOTCH1 in multiple breast cancer cell lines, representing both estrogen receptor (ER+) and triple negative breast cancer (TNBC) through direct repression of the E3 ubiquitin ligase, NEDD4L. We further show that upregulation of NOTCH1 is necessary for TIC induction downstream of miR-106b-25 in both ER + and TNBC breast cancer cells, and that re-expression of NEDD4L is sufficient to reverse miR106b-25-mediated NOTCH1 upregulation and TIC induction. Importantly, we demonstrate a significant positive correlation between miR-106b-25 and NOTCH1 protein, yet a significant inverse correlation between miR-106b-25 and NEDD4L mRNA in human breast cancer, suggesting a critical role for the miR106b-25/NEDD4L/NOTCH1 axis in the disease. Further, we show for the first time that NEDD4L expression alone is significantly associated with a better relapse-free prognosis for breast cancer patients. These data expand our knowledge of the mechanisms underlying NOTCH activation and TIC induction in breast cancer, and may provide new avenues for the development of therapies targeting this resistant subset of tumor cells.

Anaerobic membrane bioreactor for treatment of synthetic municipal wastewater at ambient temperature.

Non-woven fabric filter and poly-tetrafluoroethylene (PTFE) composite membrane were investigated to determine their applicability to treat low strength wastewater in an anaerobic membrane bioreactor (AMBR). Sludge cake resistance of the membrane was quantified using pure water flux of anaerobic sludge cake accumulated on the glass fiber filter of similar pore size. It is hypothesized that the formation of thin cake layer on the porous medium, e.g. non-woven and PTFE acts as a dynamic membrane. Thus, the capture of thin sludge cake inside the non-woven fabric matrix and accumulation on the PTFE membrane surface forms a membrane system equivalent to a commercial membrane system. The permeate quality was found to improve as the cake became more dense with filtration time. The PTFE composite membrane coated with thin PTFE film on the non-woven fabric filter enhanced the filtration performance by improving flux and minimizing the propensity of bio-fouling. The membrane flux was restored by back-flushing with permeate. The AMBR coupled with PTFE laminated membrane was operated continuously during the experiment at a cross flow velocity (CFV) of 0.1-0.2 m/sec and a transmembrane pressure (TMP) of 0.5-3 psi. Although about a month of acclimation was required to reach steady state, the effluent chemical oxygen demand (COD), volatile fatty acids (VFAs) as acetic acid, and suspended solids (SS) concentrations were below 30, 20 and 10 mg/L, respectively, during 90 days of operation with intermittent back washing. The lower operation TMP and CFV were subjected to less shear stress on the microbial community during continuous AMBR operation. In addition, thin sludge film accumulated on the membrane surface also acted as a biofilm bioreactor to remove additional COD in this study.

Improvement of the fracture toughness of hydroxyapatite (HAp) by incorporation of carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and nylon.

The potential of improving the fracture toughness of synthetic hydroxyapatite (HAp) by incorporating carboxyl functionalized single walled carbon nanotubes (CfSWCNTs) and polymerized ε-caprolactam (nylon) was studied. A series of HAp samples with CfSWCNTs concentrations varying from 0 to 1.5 wt.%, without, and with nylon addition was prepared. X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), and Transmission Electron Microscopy (TEM) were used to characterize the samples. The three point bending test was applied to measure the fracture toughness of the composites. A reproducible value of 3.6±0.3 MPa.√m was found for samples containing 1 wt.% CfSWCNTs and nylon. This value is in the range of the cortical bone fracture toughness. Increase of the CfSWCNTs content results to decrease of the fracture toughness, and formation of secondary phases.

Effectiveness of a once per week delivery of a family-based childhood obesity intervention: a cluster randomised controlled trial.

BACKGROUND: The effectiveness of once per week (OPW) delivery of a family-based childhood obesity programme was compared with twice per week (TPW) delivery in achieving health and behavioural outcomes at a population level and in improving programme attendance. Both programmes were delivered over 10-weeks, and the contact hours in the OPW and TPW programmes were 20 and 35-h, respectively. METHODS: A cluster-randomised controlled trial with stratification by local health district was conducted. Height, weight and global self esteem of participants and parent-reported diet and physical activity were measured at programme commencement and completion and at 6-month follow-up. Attendance was defined as the proportion of total sessions attended. RESULTS: There were no differences between the OPW and TPW arms in changes from pre-programme baseline for body mass index (BMI) z-score and other health and behaviourial measures at programme completion and at follow-up, except for the increase in physical activity outside of the programme at programme completion (OPW, 3.5 h/week; TPW, 1.9 h/week; p = 0.03). OPW and TPW participants attended 71.2% and 69.2% of the total sessions, respectively. Attendance was the only contributing factor to a positive BMI z-score outcome (ß = -2.45, p < 0.01) with no effects of child age and gender, language spoken at home or highest qualification of mother. CONCLUSIONS: A family-based childhood obesity programme can be delivered OPW with no compromise to health or behavioural outcomes compared with TPW. Higher attendance, as a proportion of available sessions, leads to better outcomes for children.

Yield of intensified tuberculosis case-finding activities using Xpert(®) MTB/RIF among risk groups in Nepal.

SETTING: Twenty-two districts of Nepal, where intensified case-finding (ICF) activities for tuberculosis (TB) were implemented among risk groups under the TB REACH initiative in collaboration with the National TB Programme from July 2013 to November 2015. OBJECTIVES: To assess the yield of TB screening using an algorithm with smear microscopy followed by Xpert(®) MTB/RIF. DESIGN: A descriptive study using routinely collected data. RESULTS: Of 145 679 individuals screened, 28 574 (19.6%) had presumptive TB; 1239 (4.3%) of these were diagnosed with TB and 1195 (96%) were initiated on anti-tuberculosis treatment. The yield of screening was highest among people living with the human immunodeficiency virus (PLHIV) (6.1%), followed by household contacts (3.5%) and urban slum dwellers (0.5%). Among other risk groups, such as prisoners, factory workers, refugees and individuals with diabetes, the yield was less than 0.5%. The number needed to screen to diagnose an active TB case was 17 for PLHIV, 29 for household contacts and 197 for urban slum dwellers. Of 11 525 patients from ICF and the routine programme, 112 (1%) were diagnosed with multidrug-resistant TB. CONCLUSION: There was a substantial yield of TB cases among risk groups such as PLHIV and household contacts. Although the yield in urban slum dwellers was found to be moderate, some intervention should nonetheless be targeted because of the large population and poor access to care in this group.

Contexte : Vingt-deux districts du Népal où des activités intensifiées de recherche des cas (ICF) de la tuberculose (TB) ont été mises en œuvre au sein de groupes à risque sous l'égide du projet TB REACH en collaboration avec le programme national TB entre juillet 2013 et novembre 2015.Objectifs : Evaluer le rendement du dépistage de la TB grâce à un algorithme basé sur la microscopie de frottis suivie d'un test Xpert® MTB/RIF.Schéma : Etude descriptive basée sur des données recueillies en routine.Résultats : Sur un total de 145 679 individus dépistés, 28 574 (19,6%) ont été présumés atteints de TB ; 1239 (4,3%) d'entre eux ont eu une confirmation du diagnostic de TB ; parmi ces derniers, 1195 (96%) ont mis en route un traitement anti-tuberculose. Le rendement a été le plus élevé parmi les personnes vivant avec le virus l'immunodéficience humaine (PVVIH) (6,1%) suivies par les contacts domiciliaires (3,5%) et les habitants des bidonvilles (0,5%). Dans d'autres groupes à risque comme les prisonniers, les travailleurs d'usine, les réfugiés et les diabétiques, le rendement a été inférieur à 0,5%. Le nombre de personnes à dépister (NNS) pour diagnostiquer un cas de TB active a été de 17 pour les PVVIH, de 29 pour les contacts domiciliaires et de 197 pour les habitants des bidonvilles urbains. Sur 11 525 patients émanant soit du programme ICF soit du dépistage de routine, 112 (1%) ont eu un diagnostic de TB multirésistante.Conclusion : Le rendement en termes de cas de TB dépistés parmi les groupes à risque comme les PVVIH et les contacts domiciliaires a été substantiel. Même si ce rendement a été modeste parmi les habitants des bidonvilles, ceux-ci justifient néanmoins une intervention en raison de leur nombre élevé et de leur médiocre accès aux soins.

Marco de referencia: Veintidós distritos de Nepal, en los cuales se ejecutaron actividades de búsqueda intensiva de casos (ICF) de tuberculosis (TB) en los grupos de riesgo, en el marco del proyecto TB REACH en colaboración con el programa nacional contra la TB de julio del 2013 a noviembre del 2015.Objetivos: Evaluar el rendimiento de la detección sistemática de la TB aplicando un algoritmo que comporta la baciloscopia, seguida de la prueba Xpert® MTB/RIF.Método: Fue este un estudio descriptivo a partir de los datos recogidos de manera sistemática.Resultados: De las 145 679 personas en quienes se practicó la detección, en 28 574 hubo una presunción diagnóstica de TB (19,6%); en 1239 de estos pacientes se estableció el diagnóstico de TB (4,3%); e iniciaron el tratamiento 1195 pacientes (96%). El rendimiento diagnóstico fue más alto en las personas viviendo con el virus de la inmunodeficiencia humana (PVVIH, 6,1%), seguidas de los contactos domiciliarios (3,5%) y los residentes en tugurios (0,5%). En otros grupos de riesgo de contraer la TB como los reclusos, los obreros de fábricas, los refugiados o los pacientes diabéticos el rendimiento diagnóstico fue inferior a 0,5%. El número de personas que se debieron examinar con el fin de detectar un caso de TB activa fue 17 en las PVVIH, 29 en los contactos domiciliarios y 197 en los habitantes de los tugurios. De las 11 525 personas examinadas en la ICF y el programa corriente, se diagnosticó TB multiresistente en 112 casos (1%).Conclusión: La detección sistemática de casos de TB exhibió un alto rendimiento en los grupos de riesgo como las PVVIH y los contactos domiciliarios. Aunque el desempeño en los tugurios urbanos fue moderado, es importante dirigir intervenciones a estos entornos, dado el tamaño de estas poblaciones y su acceso deficiente a la atención de salud.

Effect of gender and left ventricular dysfunction on the incidence of hypotension induced by dobutamine stress echocardiography.

BACKGROUND: Of patients who undergo dobutamine stress echocardiography (DSE), 14% to 38% experience hypotension that sometimes requires termination of the test before an adequate cardiac work-load is reached. The mechanisms of hypotension reportedly are related to peripheral vasodilation, a decrease in cardiac output, and left ventricular (LV) cavity obliteration. DSE is performed increasingly in women and in patients with LV dysfunction. However, the impact of gender and LV dysfunction on DSE-induced hypotension has not been elucidated. METHODS AND RESULTS: Clinical, hemodynamic, and echocardiographic characteristics were studied in 412 patients undergoing DSE, 82 patients with an LV ejection fraction of 40% or less, and 147 women. Hypotension, defined as a decrease in systolic blood pressure of at least 20 mm Hg, occurred in 117 (28%) patients. Hypotension was more common in women than men (36% vs 24%, P = .01). Hypotension was also more common in older adults (P = .004), persons taking diuretics (P = .025) or angiotensin-converting enzyme inhibitors (P = .01), and persons with higher baseline blood pressures (P < .0001). Hypotension was not related to the use of beta blockers, calcium channel blockers, digoxin, nitrates, LV dimensions, or ejection fraction. CONCLUSIONS: The incidence of DSE-induced hypotension is related to gender but not to the level of LV systolic function. It also is associated significantly with higher age, and use of angiotensin-converting enzyme inhibitors or diuretics.

Effect of dobutamine stress on left ventricular systolic and diastolic functions in patients with moderate to severe left ventricular dysfunction.

Dobutamine stress echocardiography (DSE) is increasingly used in patients with moderate and severe left ventricular (LV) dysfunction. However, its effect on central and peripheral hemodynamics and LV function in this patient population is not known. This study investigates the effect of dobutamine stress on LV systolic and diastolic performance and peripheral hemodynamics in 177 consecutive patients undergoing DSE. Sixty-five patients with an LV ejection fraction (EF) of < or =40% were compared with 112 patients with an EF of >40%. Compared with those with EF > 40%, patients with EF < or =40% had a faster heart rate(76 +/- 13 vs 70 +/- 13 bpm, p < 0.001), lower systolic blood pressure (127 +/- 18 vs 133 +/- 20 mm Hg, p < 0.05), lower stroke volume (60 +/- 20 vs 74 +/- 36, p = 0.01), longer LV isovolumic relaxation time (118 +/- 37 vs 108 +/- 25 msec, p < 0.05) and larger LV end-diastolic (57 +/- 9.6 vs 49 +/- 7 mm, p < 0.0001) and end-systolic (46 +/- 10 vs 32 +/- 7.9 mm, p < 0.0001) diameters. They also had a lesser increment in cardiac output (1.5 +/- 1.6 vs 3.2 +/- 4.8 L/min, p = 0.02), a smaller reduction of systolic LV size (-5.3 +/- 4.1 vs -7.0 +/- 4.3 mm, p < 0.05) and a lower propensity to LV cavity obliteration with dobutamine infusion. In conclusion, patients with an EF < or =40% have lower baseline stroke volume, systolic blood pressure, higher heart rate, and longer LV isovolumic relaxation time. They also have a smaller increase in cardiac output, a smaller reduction of LV size, and a lower propensity to LV cavity obliteration with dobutamine stress.

Left ventricular cavity obliteration during dobutamine stress echocardiography is associated with female sex and left ventricular size and function.

We investigated 568 consecutive patients undergoing dobutamine stress echocardiography to elucidate the mechanism of left ventricular (LV) obliteration. Baseline clinical and echocardiographic variables were related to dobutamine-induced LV cavity obliteration defined as approximation of LV endocardium associated with an intracavitary flow acceleration of at least 2 m/s in the absence of a distal residual cavity. The LV cavity obliteration was observed in 89 (16%) of the 568 patients and was more frequent in women and those with smaller LV dimensions, increased LV wall thickness, and higher resting ejection fractions. Despite similar peak stress levels, the cavity obliterators were less likely to have chest pain and detectable stress-induced wall motion abnormalities. We conclude that LV cavity obliteration during dobutamine stress is common and is associated with female sex, smaller LV size, presence of LV hypertrophy, and higher LV ejection fraction. Despite similar stress levels, chest pain and reversible wall motion abnormalities are observed less frequently in patients with cavity obliteration, raising the possibility of lower prevalence of coronary artery disease or masking of ischemia in this patient population.

Large atherosclerotic left main coronary aneurysm--a case report and review of the literature.

Coronary artery aneurysm (CAA) is a rare disorder, characterized by an abnormal dilatation of a localized portion of the coronary artery. It is usually diagnosed incidentally by coronary angiography. Over 50% of coronary artery aneurysms are of atherosclerotic origin. The natural history of coronary aneurysms is not well understood. Their presence is not always considered to be an operative indication; rather, the severity of the associated coronary artery disease (CAD) is what dictates a surgical approach. In the absence of obstructive CAD, the definitive treatment for this condition is unclear. The authors present the case of an isolated saccular left main coronary aneurysm with no associated flow-limiting CAD. The patient was treated medically with antiplatelet and anticoagulant medication with no adverse events at 3, 6, 9, and 12 months of follow-up.

Immediate and long-term results comparing coronary versus biliary tubular-slotted stents to treat old obstructed saphenous vein grafts.

Stenting of old obstructed saphenous vein grafts improves immediate angiographic results and long-term clinical outcome compared to standard balloon angioplasty. Comparison of results and long-term clinical outcome between different types of stents in the treatment of vein graft disease is scarce. The authors studied two matched groups of 33 patients each, receiving either coronary or biliary tubular-slotted stents in old vein graft lesions to compare immediate results and long-term clinical outcome. Patients in the two groups were matched for age and left ventricular function. Baseline angiographic characteristics, the minimal luminal diameter (MLD) (0.68 +/- 0.56 mm vs 0.61 +/- 0.51 mm, p = 0.9), and diameter stenosis (DS) (81 +/- 14% vs 82 +/- 15%) were similar between the groups. After stenting, the MLD (3.15 +/- 0.65 mm vs 3.37 +/- 0.63 mm, p = 0.9) and residual stenosis (-7 +/- 19% vs -11 +/- 21%) were also similar. The in-hospital major complications (myocardial infarction and death) (one vs eight, p = 0.01) and the combination of major and minor (bleeding and vascular) complications (eight vs 17, p = 0.02) were higher in the biliary stent group. At long-term follow-up, both groups of patients had high but comparable rates of major cardiovascular events (39% vs 45%, p = 0.62). Kaplan-Meier event-free survival analysis did not show any statistically significant difference in event-free survival (log-rank statistic 0.98). The authors conclude that patients receiving biliary stents had higher rates of immediate minor and major complications, but at long-term follow up, major cardiovascular event rates were comparable between the two groups of patients.

Provisional versus routine coronary stenting. A review.

Coronary stenting is the most commonly used coronary revascularization procedure due to the ease of use, safety and evidence that it has predictably better results in several coronary lesion subsets than balloon angioplasty alone. As opposed to routinely stenting all the stentable coronary lesions, in the provisional stenting approach, all the lesions would first be optimally angioplastied and a stent used only in the patients who would not have as good an outcome with balloon angioplasty alone. There are several theoretical advantages to this approach. The two different approaches are compared in this review. Retrospective studies and studies using immediate vessel recoil after optimal balloon angioplasty seemed to suggest that stent-like results after balloon angioplasty had similar target revascularization rates as stenting. However, a prospective randomized study primarily using angiography to guide provisional stenting suggests better outcome in the routine stenting strategy. If provisional stenting were to have similar long-term results as routine stenting, it has to be guided by techniques other than coronary angiography like coronary flow reserve or intravascular ultrasound. Even then, over half of the balloon angioplasty group will need stenting. Besides, based on prospective randomized studies, this strategy is not economically more attractive than the routine stenting strategy. Therefore routine stenting strategy is justifiable for most operators who use coronary angiography to guide their interventions. With further advancement in the stent technology like drug coating routine stenting may be even further attractive.

Use of ORP (oxidation-reduction potential) to control oxygen dosing for online sulfide oxidation in anaerobic treatment of high sulfate wastewater.

In this study, oxidation-reduction potential (ORP) was used as a controlling parameter to regulate oxygen dosing to the recycled biogas for online sulfide oxidation in an upflow anaerobic filter (UAF) system. The UAF was operated with a constant influent COD of 18,000 mg/L, but with different influent sulfates of 1000, 3000 and 6000 mg/L. The reactor was initially operated under a natural ORP of -290 mV (without oxygen injection), and was then followed by oxygenation to raise its ORP by 25 mV above the natural level for each influent sulfate condition. At 6,000 mg/L sulfate without oxygen injection, the dissolved sulfide reached 733.8 mg S/L with a corresponding free sulfide of 250.3 mg S/L, thus showing a considerable inhibition to methanogens. Upon oxygenation to raise its ORP to -265 mV (i.e., a 25 mV increase), the dissolved sulfide was reduced by more than 98.5% with a concomitant 45.9% increase of the methane yield. Under lower influent sulfate levels of 1,000 and 3,000 mg/L, the levels of sulfides produced, even under the natural ORP, did not impose any noticeable toxicity to methanogens. Upon oxygenation to raise the ORP by +25 mV, the corresponding methane yields were actually reduced by 15.5% and 6.2%, respectively. However, such reductions were not due to the adverse impact of the elevated ORP; instead, they were due to a diversion of some organic carbon to support the facultative activities inside the reactor as a result of excessive oxygenation. In other words, to achieve satisfactory sulfide oxidation for the lower influent sulfate conditions, it was not necessary to raise the ORP by as much as +25 mV. The ORP increase actually needed depended on both the influent sulfate and also actual wastewater characteristics. This study had proved that the ORP controlled oxygenation was reliable for achieving consistent online sulfide control.