Clinical use of venoarterial extracorporeal membrane oxygenation.

With advances in mechanical circulation, venoarterial extracorporeal membrane oxygenation has become an established technique to provide cardiopulmonary support for patients with cardiovascular collapse. This article reviews the physiological principles of such extracorporeal technique and its interaction with the native heart. Practical aspects including equipment, patient selection, and common complications with their prevention and specific management are summarised. The strategy for weaning from venoarterial extracorporeal membrane oxygenation is also discussed.

Clinical use of venovenous extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation has been used clinically for more than 40 years. The technique provides respiratory and/or circulatory support via venovenous and veno-arterial configurations, respectively. We review the basic physiological principles of extracorporeal membrane oxygenation systems in venovenous extracorporeal membrane oxygenation. Clinical aspects including patient selection, equipment, setup, and specific patient management are outlined. Pros and cons of the use of extracorporeal membrane oxygenation in respiratory failure are discussed.

Acquired factor V inhibitor in a patient receiving venous-venous extracorporeal membrane oxygenation for Legionella pneumonia.

We report a rare complication of factor V deficiency in a patient having Legionella pneumonia. This patient also had other complications like severe acute respiratory distress syndrome, acute kidney injury, and septic shock that required venous-venous extracorporeal membrane oxygenation support. This is the first reported case of acquired factor V deficiency in a patient receiving extracorporeal membrane oxygenation for Legionella pneumonia. With the combined use of intravenous immunoglobulin, rituximab and plasma exchange, we achieved rapid clearance of the factor V inhibitor within 1 week so as to allow safe decannulation of extracorporeal membrane oxygenation.

Three-year experience of using venovenous extracorporeal membrane oxygenation for patients with severe respiratory failure.

OBJECTIVE: To present the 3-year experience of using venovenous extracorporeal membrane oxygenation for patients with severe respiratory failure in a single centre in Hong Kong. DESIGN: Case series. SETTING: A 19-bed Intensive Care Unit of a tertiary hospital in Hong Kong. PATIENTS: All patients who were managed with venovenous extracorporeal membrane oxygenation from 1 July 2010 to 30 June 2013 in the Intensive Care Unit. RESULTS: Overall, 31 patients (mean age, 42.2 years, standard deviation, 14.1 years; 21 males) received venovenous extracorporeal membrane oxygenation for the treatment of severe respiratory failure. Of these, 90.3% (28 patients) presented with pneumonia as the cause of the respiratory failure, and 22 of them had identifiable causes. A total of nine (29.0%) patients were diagnosed to have H1N1 infection. The median Murray score was 3.5 (interquartile range, 3.0-3.5); the median duration of venovenous extracorporeal membrane oxygenation support was 5.0 (2.8-8.6) days; and the median duration of mechanical ventilator support was 18.2 (7.8-27.9) days. The overall intensive care unit mortality was 19.4% (n=6). The overall in-hospital mortality and the 28-day mortality were both 22.6% (n=7). Among the 22 patients who had identifiable infective causes, those suffering from viral infection had lower intensive care unit and hospital mortality than those who had bacterial infection (8.3% vs 20.0%). All the H1N1 patients survived. Complications related to extracorporeal membrane oxygenation included severe bleeding (n=2; 6.5%) and mechanical complications of the circuits (n=3; 9.7%). CONCLUSIONS: Venovenous extracorporeal membrane oxygenation is an effective adjunctive therapy and can be used as a life-saving procedure for carefully selected patients with severe acute respiratory distress syndrome when the limits of standard therapy have been reached.

Uncommon cause of severe pneumonia: co-infection of influenza B and Streptococcus.

Influenza and pneumococcus co-infection can cause severe morbidity and mortality. Usually, this entails influenza A, while infection by influenza B is rarely serious. The literature describes influenza A epidemics leading to prolific loss of lives, notably the 1918 epidemic was blamed for the deaths of 40 to 50 million people. In this report, four patients were infected by influenza B during the influenza epidemic of 2011/12 in Hong Kong. All of them were previously healthy and had no chronic diseases; they were admitted to the hospital due to influenza-like symptoms. They rapidly deteriorated with multi-organ failure, and were subsequently diagnosed to be infected with influenza B and streptococci that gave rise to severe pneumonia. Three of them were infected with Streptococcus pneumoniae and one with Streptococcus pyogenes. All of them had leukopenia, septic shock, and acute kidney injury; two of whom died despite aggressive antibiotic treatment and organ support in the intensive care unit. According to the literature, this is the second case report of severe invasive pneumococcal pneumonia secondary to influenza B infection.

Single-port vs. conventional multi-port access laparoscopy-assisted vaginal hysterectomy: comparison of surgical outcomes and complications.

OBJECTIVE: To compare surgical outcomes and complications between single-port access (SPA) and multi-port access (MPA) laparoscopy-assisted vaginal hysterectomy (LAVH). STUDY DESIGN: A retrospective review of medical records was performed in patients who underwent LAVH for non-malignant gynaecological diseases at Eun Hospital between April 2010 and April 2012. One hundred and twenty women underwent SPA LAVH using a transumbilical three-channel single-port system and 130 women underwent conventional MPA LAVH. Surgical outcomes and complications were compared between the two groups. RESULTS: The outcomes of the SPA-LAVH group vs. the conventional MPA-LAVH group were as follows: mean±standard deviation total operative time (73.1±24.3 vs. 70.3±22.1min, p=0.349), largest dimension of uterus (10.7±2.3 vs. 10.8±2.8cm, p=0.847), weight of extirpated uterus (311±185 vs. 339±234g, p=0.298) and change in haemoglobin (1.7±0.8 vs. 2.0±0.9g/dl, p=0.025). The incidence of complications was similar in each group (20 vs. 16 patients, p=0.327). Unplanned intra-operative laparotomy was not necessary in either group, and there were no cases of bowel injury or main vessel injury in either group. In total, there were three bladder injuries: one in the SPA-LAVH group and two in the MPA-LAVH group. The postoperative course was uneventful in most patients, but six patients had a transient paralytic ileus (four in the SPA-LAVH group and two in the MPA-LAVH group) and 10 patients had a pelvic haematoma (five in each group), all of whom recovered following conservative management. Port-related complications were rare, but one patient in the SPA-LAVH group had a port-site umbilical hernia. CONCLUSION: Use of SPA and MPA LAVH has similar results in terms of surgical outcomes and complications.

Biofunctionalized indigo-nanoparticles as biolabels for the generation of precipitated visible signal in immunodipsticks.

A novel class of organic nanoparticles as biolabels that can generate an instant visible signal was applied to immunodipsticks. A new principle for signal generation based on hydrolysis of colourless signal precursor molecules to produce coloured signal molecules followed by signal precipitation and localization was demonstrated. The nanoparticle biolabels were applied to sandwich immunoassays for the detection of mouse immunoglobulin G (M IgG). In the presence of M IgG, a nanoparticle-immunocomplex was formed and bound on the test zone immobilized with goat anti M IgG (Gt α M IgG). A blue line was developed on the test zone upon the addition of a signal developing reagent. An optical signal could be simply assessed using naked eyes or quantified using a reading device. The lowest visible signal that could be observed using naked eyes was found to be 1.25 µg L(-1) M IgG. The nanoparticle biolabel also showed a better sensitivity (signal-to-noise ratio) compared with the conventional colloidal gold biolabel. This novel class of organic nanoparticles offers an alternative biolabel system for the development of point-of-care immunodipsticks.

CT appearance of complications related to thoracic endovascular aortic repair (TEVAR): a pictorial essay.

Thoracic endovascular aortic repair (TEVAR) is a recognized treatment for various diseases involving the thoracic aorta. Patients treated with TEVAR require lifelong surveillance for potential complications, with CT being highly utilized in most centres. Endoleak is the most common complication and can be detected using CT. However, other complications such as stent strut perforations and end organ ischemia can also be detected on CT. The purpose of this pictorial essay is to illustrate the CT appearance of post-TEVAR complications encountered in our institution and to highlight their significance.

Determinants of chronic obstructive pulmonary disease in Chinese patients in Hong Kong.

BACKGROUND: The prevalence of chronic obstructive pulmonary disease (COPD) is rising in many parts of the world. This is a study of risk factors for COPD in Chinese patients in Hong Kong. DESIGN: Case-control study matched by sex and age (+/-5 years). METHODS: A total of 289 consecutive patients with COPD were recruited from out-patient clinics while healthy controls were recruited from two sources: random population and community centres for senior citizens. All patients and controls underwent a questionnaire-based interview and spirometry. RESULTS: The mean ages of COPD patients and controls were 71.1 +/- 9.4 and 67.5 +/- 9.3 years, respectively. The male to female ratio of COPD patients was 5 to 1. Smoking was found to be the most important determinant for COPD, followed by poor education and low body mass index adjusted for confounders. A dose-dependent relationship was found between the risk of COPD and pack-years smoked. Place of birth, exposure to environmental tobacco smoke and a history of asthma and tuberculosis were not associated with increased risk of COPD. CONCLUSION: Despite a progressive reduction in prevalence, smoking remains the most important predictor of COPD in Hong Kong. Greater anti-smoking efforts are warranted.

Cogan's syndrome with recurrent carotid and aortic aneurysms: a potentially fatal disorder mimicking Marfan syndrome.

Cogan's syndrome (CS) is a rare multisystemic disease characterized by vestibuloauditory dysfunction, inflammatory eye disease and vasculitis. Aortic aneurysms due to aortitis are under-recognized in CS, and are potentially fatal, with two of eight reported cases dying from aneurysm/arterial rupture. The presence of aneurysms was not recognized antemortem in both cases, highlighting the importance of early detection to prevent this potentially fatal outcome. We report a 17-year-old Chinese male with recurrent carotid and aortic aneurysms, bilateral sensorineural hearing loss, and recurrent scleritis who was initially thought to have Marfan syndrome. The diagnosis of CS was made 4.5 years after initial presentation, during which time recurrent aneurysms due to active aortitis (with aneurysmal rupture on one occasion) necessitated four surgical procedures. Treatment with methotrexate and corticosteroids resulted in no recurrence of aneurysms over 2 years of follow-up. This case illustrates (i) the challenges in diagnosing CS when various manifestations occur separately over a relatively long time period, (ii) that detection of aortic aneurysms in young patients, especially if recurrent, should prompt investigations for vasculitis/aortitis to prevent potentially fatal aneurysm rupture, and (iii) that methotrexate and high-dose corticosteroids may be effective in preventing development of further aneurysms in CS patients.

Fluorogenic nanocrystals for highly sensitive detection of C-reactive protein.

A solid-phase sandwich fluorescence immunoassay using nanocrystals of a fluorogenic precursor, fluorescein diacetate (FDA), conjugated with monoclonal antibodies for the detection of C-reactive protein (CRP), is described. FDA nanocrystals were coated with distearoylglycerophosphoethanolamine (DSPE), modified with amino(poly(ethylene glycol))(PEG(2000)-Amine) as an interface for coupling biomolecules. CRP was chosen as a model analyte because of its widely accepted role as a marker for acute inflammation and prospective heart failure. A low limit of detection (1.10 microg l(-1)) and high precision (CV = 2.72-9.48%) were achieved. Following the immunoreaction, the monoclonal anti-CRP conjugated nanocrystals were released by hydrolysis and dissolution instigated by the addition of a large volume of organic solvent-sodium hydroxide mixture. Using human serum samples from 66 patients with high heart attack risk and 19 healthy blood donors, this CRP fluorescence immunoassay showed a good correlation to the commercially available, turbidimetric immunoassay for CRP. This result was corroborated by the Bland-Altman plot that showed a mean difference between the two methods of only 0.36+/-1.46 mg l(-1). The study demonstrates that the organic fluorogenic FDA nanocrystals can be applied for the detection of CRP, which is a clinically interesting plasma protein with a low limit of detection.

Declines in tobacco brand recognition and ever-smoking rates among young children following restrictions on tobacco advertisements in Hong Kong.

BACKGROUND: We compared the recognition of tobacco brands and ever-smoking rates in young children before (1991) and after (2001) the implementation of cigarette advertising restrictions in Hong Kong and identified continuing sources of tobacco promotion exposure. METHODS: A cross-sectional survey of 824 primary school children aged from 8 to 11 (Primary classes 3-4) living in two Hong Kong districts was carried out using self-completed questionnaires examining smoking behaviour and recognition of names and logos from 18 tobacco, food, drink and other brands common in Hong Kong. RESULTS: Ever-smoking prevalence in 2001 was 3.8 per cent (1991, 7.8 per cent). Tobacco brand recognition rates ranged from 5.3 per cent (Viceroy name) to 72.8 per cent (Viceroy logo). Compared with 1991, in 2001 never-smoker children recognized fewer tobacco brand names and logos: Marlboro logo recognition rate fell by 55.3 per cent. Similar declines were also seen in ever-smoker children, with recognition of the Marlboro logo decreasing 48 per cent. Recognition rates declined amongst both boys and girls. Children from non-smoking families constituted 51 per cent (426) of the sample, whereas 34.5 per cent (284), 8.5 per cent (70), 1.7 per cent (14) and 4.4 per cent (36) of the children had one, two, three or more than three smoking family members at home, respectively. Tobacco brand recognition rates and ever-smoking prevalence were significantly higher among children with smoking family members compared with those without. Among 12 possible sources of exposure to cigarette brand names and logos, retail stalls (75.5 per cent; 622), indirect advertisements (71.5 per cent; 589) and magazines (65.3 per cent; 538) were ranked the most common. CONCLUSION: Advertising restrictions in Hong Kong have effectively decreased primary-age children's recognition of tobacco branding. However, these children remain vulnerable to branding, mostly through exposure from family smokers, point-of-sale tobacco advertisement and occasional promotions. Action to curb these is now required.

Large-scale mercury exposure due to a cream cosmetic: community-wide case series.

OBJECTIVE: To describe demographic characteristics, patterns of use, reported symptoms, and laboratory results associated with mercury exposure among people who used a beauty cream containing mercury. DESIGN. Descriptive study of a case series. SETTING: The Hong Kong community. PARTICIPANTS: Users of a cream cosmetic who contacted the Department of Health following a public announcement. MAIN OUTCOME MEASURES: Urine and blood mercury concentrations, cream mercury content, self-reported symptoms, duration of cream use, and duration since last cream use. RESULTS: We interviewed 314 cream users, 99% of whom were women. The mean urine and blood mercury concentrations of 286 users, who submitted a urine or blood sample, were 45.2 microg/L (reference level, <20 microg/L) and 17.1 microg/L (reference level, <10 microg/L), respectively; 65% of these participants had elevated mercury concentrations. The mercury content of the cream cosmetic ranged from 660 to 57 000 ppm. Seventy-eight percent of all cream users reported no symptoms, but absence of symptoms was not predictive of low urine and blood mercury concentrations. Urine mercury concentrations were significantly higher among people who last used the cream within 45 days. Blood mercury concentrations were elevated following cream use for as short as 2 days. CONCLUSIONS: The majority of cream users had increased urine or blood mercury concentrations but remained asymptomatic, implying that the incidence of overt symptomatic mercury poisoning resulting from dermal application of creams with mercury content lower than 57 000 ppm is low. Doctors should take a history of the use of cosmetics if patients have clinical or laboratory evidence of mercury exposure; such cases should be reported to public health authorities.

Determinants of adherence to highly active antiretroviral therapy (HAART) in Chinese HIV/AIDS patients.

OBJECTIVE: Drug adherence is crucial to the success of highly active antiretroviral therapy (HAART) in the treatment of HIV disease. Adherence to HAART and its determinants may, however, differ across HIV/AIDS populations. METHODS: We retrospectively studied drug adherence by self-report in HIV-1 infected Chinese patients who have been on HAART for at least 1 year as at the end of year 2000. HAART is defined as three or more antiretrovirals with at least one protease inhibitor or non-nucleoside analogue reverse transcriptase inhibitor. RESULTS: The last drug adherence level assessed by self-report in 161 Chinese patients were: grade A (100%) - 130, 80.7%; grade B (95-99%) - 25, 15.5%; grade C (90-94%) - three, 1.9% and grade D (< 90%) - three, 1.9%. Patients with full adherence were more likely to have undetectable (< 500 copies/mL) plasma virus level (adjusted OR, 4.22; 95% CI, 1.75-12.33). Patients' demographics, HIV disease status and antiretroviral regimen did not affect adherence. Partial drug adherence was, however, independently associated with the psychosocial factors of missing clinic appointments (adjusted OR, 3.13; 95% CI, 1.23-8.33), forgetfulness (adjusted OR, 4.55; 95% CI, 1.64-12.5) and a busy work life (adjusted OR, 6.67; 95% CI, 1.75-25). CONCLUSION: There were similarities and differences in determinants affecting HAART adherence in Chinese compared with other patients. Psychosocial factors rather than HIV disease or treatment were more important factors in our Chinese patients. The relevance of patient populations and care setting for adherence to HAART shall be further studied.

Multi-axial spine biomechanical testing system with speckle displacement instrumentation.

This paper reports on the design and development of a multi-axis (up to 6 axes) mechanical tester for spinal research and testing. The developed spine tester allowed true motion to be simulated on a specimen in pure or combined modes. To demonstrate the capability of the new tester flexural stiffness properties of sheep lumbar motion segments were evaluated together wiith a non-contact speckle displacement measurement system. The flexural stiffness of the specimens was measured and compared under constrained and non-constrained testing conditions; with relieving of shear forces (non-constrained), it was found that the specimen behaved in a 'stiffer' manner.

Two liters of polyethylene glycol-electrolyte lavage solution versus sodium phosphate as bowel cleansing regimen for colonoscopy: a prospective randomized controlled trial.

BACKGROUND AND STUDY AIMS: As a bowel cleansing agent for colonoscopy, sodium phosphate (NaP) has been reported to have equal effectiveness and better patient tolerance in comparison with 4 l polyethylene glycol-electrolyte lavage (PEG-EL) solution. Poor patient tolerance is frequently associated with a large amount of fluid consumed, and better patient tolerance might therefore be expected if the volume of PEG-EL solution could be reduced. This study aimed to compare 2 l PEG-EL solution with NaP in relation to patients' tolerance and its effectiveness as a bowel cleansing agent. PATIENTS AND METHODS: Two hundred consecutive patients admitted to the day-procedure ward for elective colonoscopy were prospectively randomized to receive either a 2-l PEG-EL solution or a 90-ml oral NaP regimen. Patients with a history of congestive heart failure, impaired renal function (creatinine > 1.5 mg/dl), or previous colectomy were excluded from the study. The patients completed a questionnaire to assess their tolerance of bowel preparation before the colonoscopy. Endoscopists, who were blinded to the type of regimen that had been used, scored the adequacy of bowel preparation from the rectum to cecum using a defined endoscopic score. RESULTS: Two hundred patients were included in this randomized trial. Nine patients were excluded, due to either an incomplete questionnaire (two in the PEG-EL group, one in the NaP group) or inability to complete the bowel preparation regimen (four in the PEG-EL group and two in the NaP group). The demographic data were comparable in the two groups. There were no differences between the two groups with regard to willingness to repeat the regimen, ease of consumption, acceptability of the bowel preparation regimen, or the endoscopists' satisfaction with the quality of bowel preparation. The NaP group had a better mean endoscopic score at the cecum compared with the PEG-EL group (1.47 +/- 1.15 vs. 1.05 +/- 0.76; P = 0.007). CONCLUSIONS: The effectiveness and patient tolerance of the 2-l PEG-EL solution is comparable with that of oral NaP. The 2-l PEG-EL solution is therefore an effective alternative as a bowel-cleansing agent for colonoscopy.

Removal of hydrophobic dyestuff from dyeing wastewater by photo-sensitization process.

Recently, photochemical reaction became more important in view of using UV in textile dyeing wastewater treatment processes, in which neither chemical sludges nor toxic residues are left in the treated effluent. The photodegradation of hydrophobic dye (Palanil Yellow 5R, PY-5R) in the presence of acetone, which performs as a solvent and/or a photo-sensitizer, was investigated in this study. The results demonstrated that photochemical reaction in the presence of acetone could rapidly and effectively enhance color removal at a wavelength of 253.7 nm. The photodegradation follows pseudo first-order decay. The rate constants and decay quantum yields of dye degradation by UV depend on the solution pH and solvent system, (i.e., acetone to water ratio). The photosensitization of the disperse dye was found to be optimized at pH 9 and in 0.5 (v:v) acetone-water ratio.

Expeditious synthesis and chromatographic resolution of (+)- and (-)-trans-1-benzylcyclohexan-1,2-diamine hydrochlorides.

The hitherto unknown (-)- and (+)-1-benzylcyclohexan-1,2-diamine hydrochlorides 4a. HCl and 4b. HCl were synthesized by means of diastereoselective alpha-iminoamine rearrangement with subsequent imine reduction and hydrogenolysis. The relative trans-configuration as well as the absolute (1S,2R) and (1R,2S) configurations of 4a and 4b, respectively, were elucidated on the basis of an X-ray analysis of 3b. HCl. The enantiomeric excess (ee) values of the title compounds (>99%) were determined by chiral HPLC on a Chirex (D) Penicillamine column.