The mortality and morbidity of end-stage renal failure patients undergoing conventional thrice weekly in-centre haemodialysis remain alarmingly high despite continuing advances in haemodialysis technologies and improvements in clinical care. Home haemodialysis continues to be under-utilised in many parts of the world despite the reported benefits. Alternative haemodialysis regimens including longer and/or more frequent dialysis (e.g. nocturnal haemodialysis and short daily haemodialysis), haemodiafiltration and the use of high flux dialysers have become more widespread in recent years as nephrologists struggle to improve the dismal survival figures. Whilst most of the encouraging data have come from observational studies, many randomised controlled trials which will provide more robust data are already underway. This review aims to provide a concise update of the recent and novel trends in haemodialysis.
Humans ; Kidney Failure, Chronic ; therapy ; Renal Dialysis ; trends

INTRODUCTIONResection or even biopsy of an intra-axial mass lesion in close relationship to eloquent cortex carries a major risk of neurological deficit. We review the safety and effectiveness of craniotomy under local anaesthesia and monitored conscious sedation for resection of mass lesions involving eloquent cortex.

MATERIALS AND METHODSWe performed a 3-year retrospective review of patients who underwent awake craniotomy under local anaesthesia at the National Neuroscience Institute, Singapore. All patients had tumours in close proximity to eloquent cortex, including speech areas in the dominant hemisphere as well as primary sensory and motor cortex in either hemisphere. Brain mapping was performed by direct cortical stimulation using the Ojemann stimulator to identify a safe corridor for surgical approach to the tumour. Intraoperative physiological monitoring was carried out by assessment of speech, motor and sensory functions during the process of surgical resection. All resections were evaluated and verified by postoperative imaging and reviewed by an independent assessor. Postoperative complications and neurological deficits, as well as extent of tumour resection, were evaluated.

RESULTSA total of 20 patients underwent stereotactic resection over a period of 3 years from July 2003 to August 2006. There were 7 male patients and 13 female patients, with a mean age of 39.8 years. The average length of stay was 5.5 days. There were no major anaesthetic complications and no perioperative deaths. Postoperative neurological deficits were seen in 6 patients (30%) and this was permanent in only 1 patient (5%). The degree of cytoreduction achieved was greater than 90% in 58% of patients and a further 21% had greater than 80% cytoreduction.

CONCLUSIONTumour surgery with conscious sedation in combination with frameless computer stereotactic guidance is a safe technique that allows maximal resection of lesions in close relationship to eloquent cortex and has a low risk of neurological deficit.

Adolescent ; Adult ; Aged ; Anesthetics, Local ; administration & dosage ; Brain Neoplasms ; surgery ; Cerebral Cortex ; physiopathology ; surgery ; Child ; Conscious Sedation ; Craniotomy ; Female ; Humans ; Male ; Medical Audit ; Middle Aged ; Outcome Assessment (Health Care) ; Perioperative Care ; Retrospective Studies ; Singapore

INTRODUCTION: ADAMTS13 (a disintegrin-like and metalloproteinase with a thrombospondin Type 1 motif, member 13) plays a fundamental role in the regulation of haemostasis and thrombosis. Its deficiency leads to an accumulation of ultra-large von Willebrand multimers, inducing spontaneous platelet aggregation, thrombosis in the microvasculature, and thrombotic thrombocytopenic purpura (TTP), a condition with 90% mortality when left untreated. Prompt quantification of ADAMTS13 antigen, activity and autoantibody plays a crucial role in the diagnosis and management of TTP and can help differentiate it from other thrombotic microangiopathies (TMAs). Reference ranges for ADAMTS13 are generally derived from Caucasian patients. Given that polymorphism in the ADAMTS13 gene can be associated with variable ADAMTS13 levels, we aimed to establish the first reference range in Singapore and provide a crucial laboratory test for institutions here and elsewhere. METHODS: 150 healthy voluntary donors (75 men, 75 women) aged 21-60 years, with an ethnic mix mirroring Singapore's population profile, were recruited. ADAMTS13 antigen, activity and autoantibody levels were measured using the fluorescence resonance energy transfer-vWF73 and enzyme-linked immunosorbent assay methodologies. RESULTS: Levels (activity 0.65-1.79 IU/mL, antigen 0.36-1.17 IU/mL, autoantibody 1.4-12.5 U/mL) were not statistically different between the genders and various age groups. CONCLUSION TTP and TMAs are encountered in a wide range of specialties. The availability of new assays in Singapore will aid clinicians in the timely management of these conditions. Standardising reference ranges established for Singapore against World Health Organization standards allows harmonisation of measurements between laboratories and for future research collaborations.
ADAMTS13 Protein/analysis* ; Adult ; Enzyme-Linked Immunosorbent Assay ; Female ; Humans ; Male ; Purpura, Thrombotic Thrombocytopenic/diagnosis* ; Reference Values ; Singapore

INTRODUCTIONIt has been noted that SARS transmission is characterised by a few super-spreading events (SSEs) giving rise to a disproportionate number of secondary cases. Clinical and environmental features surrounding the index cases involved were compared with cases in non- SSEs.

MATERIALS AND METHODSData on 231 cases of probable SARS admitted to Tan Tock Seng Hospital (TTSH) were used. Index cases directly causing 10 or more secondary cases were classified as having been involved in SSEs; all others were defined as non-SSEs.

RESULTSOnly 5 cases were involved in SSEs; all 5 were isolated on day 5 of illness or later, and spent at least a brief period in a non-isolation ward; in contrast, amongst the 226 non-SSE cases, only 40.7% and 4.0% were isolated late and admitted to non-isolation wards respectively, and only 3.1% had both these environmental features present; the differences were highly significant (P = 0.012, P <0.001 and P <0.001 by Fisher's Exact test). When compared to 7 non-SSE cases with delayed isolation and an admission to non-isolation wards, SSEs were more likely to have co-morbid disease or require ICU care at time of isolation (P = 0.045 for both factors).

CONCLUSIONSSEs were likely due to a conglomeration of environmental factors of delayed isolation and admission to a non-isolation ward, coupled with severe disease stage at time of isolation.

Adult ; Female ; Humans ; Male ; Middle Aged ; Severe Acute Respiratory Syndrome ; epidemiology ; transmission ; Singapore ; epidemiology

Heparin has been widely used for intradialytic anticoagulation since the 1940s. Heparin induced anaphylaxis can be life threatening, mandating early recognition and intervention. However, due to its relative rarity many physicians remain unaware. We report the case of a 70-year-old woman requiring dialysis, who developed recurrent anaphylaxis to intradialytic heparin. We describe a systematic approach to confirm the suspected heparin allergy, which must include an evaluation of predisposing factors, the dialysis equipment and concomitant medications. Further workup for safe alternatives employing skin prick and intradermal tests, as well as provocation tests are discussed.
Aged ; Anaphylaxis ; Causality ; Dialysis ; Drug Hypersensitivity ; Female ; Heparin ; Humans ; Hypersensitivity ; Intradermal Tests ; Skin ; Skin Tests

INTRODUCTIONThere is increasing belief that a formal protocol-based multidisciplinary care model should be adopted as an optimal care model in oncology. However, there is minimal outcome evidence to demonstrate an improvement in patient care. The aim of this study was to compare clinical quality outcomes between patients with high-grade glioma managed at one hospital using a formal neuro-oncology multidisciplinary tumour clinic (MTC) and a second hospital with a traditional on-call referral pattern (non-MTC).

MATERIALS AND METHODSPatients with high-grade glioma managed radically with radiation therapy at 2 Singapore hospitals from May 2002 to May 2006 were entered into a prospective database. Patients were grouped into management via MTC or non-MTC. Four clinical quality indicators were chosen retrospectively to assess the variation in practice: a) Use of computed tomography (CT) or magnetic resonance (MR) imaging post-resection (POI) for assessment of residual disease; b) Commencement of radiation therapy (RT) within 28 days of surgery; c) Adjuvant chemotherapy use for glioblastoma multiforme (CTGBM) and d) Median survival.

RESULTSSixty-seven patients were managed radically, with 47 by MTC and by 20 by non-MTC. MTC patients were more likely to have POI (P = 0.042), and CTGBM (P = 0.025). Although the RT start time was similar for the whole cohort (60% versus 45%: P = 0.296); for GBM patients, the RT start was earlier (63% vs 33% P = 0.024). The median survival for the MTC group was 18.7 months versus 11.9 months for the non-MTC group (P = 0.11).

CONCLUSIONClinical quality outcomes were significantly improved in patients with high-grade glioma managed in this neuro-oncology MTC.

Cancer Care Facilities ; Female ; Glioma ; classification ; drug therapy ; pathology ; radiotherapy ; Humans ; Interdisciplinary Communication ; Male ; Middle Aged ; Prospective Studies ; Quality Indicators, Health Care ; Quality of Health Care ; Survival Analysis

INTRODUCTIONThe aims of this article were to review the role of surgical resection in the management of high-grade gliomas and to determine whether there is any survival benefit from surgical resection.

METHODSA literature review of the influence of surgical resection on outcome was carried out. Relevant original and review papers were obtained through a PubMed search using the following keywords: glioma, resection, prognosis and outcome.

RESULTSPresently, there is a lack of evidence to support a survival benefit with aggressive glioma resection, but this should not detract patients from undergoing surgery as there are many other clinical benefits of glioma excision. In addition, limiting surgical morbidity through the use of adjuvant techniques such as intraoperative magnetic resonance imaging (MRI), functional MRI and awake craniotomy is becoming increasingly important.

CONCLUSIONSIdeally, a randomised controlled trial would be the best way to resolve the issue of whether (and to what extent) surgical resection leads to improvements in patient outcome and survival, but this would not be ethical. The second best option would be well-controlled retrospective studies with a multivariate analysis of all potential confounding factors.

Glioma ; classification ; surgery ; Humans ; Singapore ; Survival Analysis

INTRODUCTIONDuplex ultrasonography is an excellent non-invasive screening tool for carotid artery stenosis. The aim of this study was to evaluate optimal ultrasonographic criteria for determination of internal carotid artery stenosis with reference to digital subtraction angiography.

MATERIALS AND METHODSFrom January 1995 to December 2003, 114 symptomatic patients underwent both duplex ultrasonography and angiography. Seven velocity criteria were compared with angiographic stenosis and receiver operating characteristic curves were used to determine the best cutoff for each criteria.

RESULTSInternal carotid artery/common carotid artery systolic velocity ratios (PSV ICA/PSV CCA) and systolic internal carotid artery/diastolic common carotid artery ratios (PSV ICA/EDV CCA) were superior to other criteria for diagnosing internal carotid artery stenosis. For 50% stenosis, the best criterion of PSV ICA/PSV CCA was 1.5 [sensitivity 100%, specificity 85%, area under the curve (AUC) 99%], and the best criterion of PSV ICA/EDV CCA was 3.5 (sensitivity 100%, specificity 58%, AUC 99%). For 60% stenosis, the best criterion of PSV ICA/PSV CCA was 2.6 (sensitivity 100%, specificity 94%, AUC 99%), and the best criterion of PSV ICA/EDV CCA was 10.3 (sensitivity 100%, specificity 96%, AUC 99%). For 70% stenosis, the best criterion of PSV ICA/PSV CCA was 3.1 (sensitivity 100%, specificity 91%, AUC 99%), and the best criterion of PSV ICA/EDV CCA was 10.3 (sensitivity 100%, specificity 91%, AUC 99%).

CONCLUSIONOur study showed that velocity ratios are superior to other criteria for detecting carotid stenosis. Each laboratory needs to validate its own results.

Aged ; Angiography, Digital Subtraction ; Area Under Curve ; Carotid Artery, Internal ; diagnostic imaging ; pathology ; Carotid Stenosis ; classification ; diagnostic imaging ; Female ; Humans ; Male ; Middle Aged ; ROC Curve ; Sensitivity and Specificity ; Ultrasonography, Doppler, Duplex

Primary malignant B-cell-type dural lymphoma is a rare subtype of primary central nervous system lymphoma (PCNSL). We herein report an unusual case of diffuse B-cell lymphoma that presents as a chronic subdural haematoma without extracranial involvement. The notable aspects of this case include the patient's immunocompetence, a short clinical history of symptom onset, rapid neurological deterioration and a fi nal diagnosis of high-grade PCNSL. This case highlights the challenges neurosurgeons face, especially in the emergency setting, when the disease manifests in varied presentations.
Brain Neoplasms ; diagnosis ; surgery ; Hematoma, Subdural ; diagnosis ; surgery ; Humans ; Lymphoma, B-Cell ; diagnosis ; surgery ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Multimodal Imaging ; Tomography, X-Ray Computed

INTRODUCTIONMulti-voxel MR spectroscopic imaging (MRSI) provides chemical metabolite information that can supplement conventional MR imaging in the study of intracranial neoplasia. Our purpose was to use a robust semi-automated spectroscopic analysis to distinguish intracranial tumours from non-neoplastic disease.

MATERIALS AND METHODSTwenty intracranial tumours and 15 patients with non-neoplastic disease confirmed on histological examination or serial neuroimaging were studied with 2-dimensional MRSI using point-resolved spectroscopic (PRESS) imaging localisation. Using semi-automated post-processing software, spectra were analysed for peak heights of choline (Cho), creatine (Cr), N-acetyl aspartate (NAA), lactate (Lac) and lipid (Lip). Normalised Cho (nCho) ratios, computed by dividing maximum Cho in the lesion by the normal-appearing brain, were compared between intracranial tumours and non-neoplastic disease.

RESULTSMeningiomas displayed homogeneously elevated Cho. Malignant tumours, especially large glioblastoma multiforme, displayed inhomogeneity of metabolites within the tumour. All tumours had elevation of nCho >1 (mean 1.91 +/- 0.65), and non-neoplastic diseases had tumour nCho <1 (mean 0.91 +/- 0.46), which was significantly lower (P <0.05). Two patients with non-neoplastic lesions, one with subacute cerebral infarction and the other with cryptococcoma, had elevated Cho compared to normal tissue (false positive rate 13%).

CONCLUSIONUsing semi-automated MRSI method, a simplified normalised Cho algorithm provides a method to distinguish intracranial tumours from non-neoplastic disease.

Adult ; Aged ; Aged, 80 and over ; Biomarkers, Tumor ; analysis ; Brain Neoplasms ; diagnosis ; metabolism ; Diagnosis, Differential ; Female ; Humans ; Magnetic Resonance Spectroscopy ; methods ; Male ; Middle Aged ; Retrospective Studies