Recovery in knee range of motion reaches a plateau by 12 months after total knee arthroplasty.

PURPOSE: The primary aim of this study was to identify the time point at which improvements in knee range of motion reach a plateau, if any. The secondary aim of this study was to investigate the correlation between the improvements in knee range of motion and patient-reported outcomes [Oxford knee score (OKS) and SF-36]. The hypothesis is that there is a time point at which the recovery in the knee range of motion after total knee arthroplasty (TKA) plateaus. METHOD: A prospective study of 145 patients who underwent TKA was conducted. All TKAs were performed by the same surgeon. OKS and SF-36 scores were measured preoperatively and at 6, 12, and 24 months. Range of motion was measured preoperatively and at 1, 3, 6, 12, and 24 months postoperatively. RESULTS: This study shows that for surgeon/therapist reported range of motion, a plateau in recovery was reached at 12 months after TKA. It was also found that range of extension is significantly correlated with OKS, whereas range of flexion was not significantly correlated with OKS. CONCLUSIONS: Knowledge of when patients fully recover after TKA will allow appropriate counseling of patients during preoperative consultation. Also, this knowledge will enable surgeons/therapists to better monitor the rehabilitation progress of TKA patients, and make adjustments to the rehabilitation protocol. In addition, our study shows that objective surgeon-/therapist-measured outcome (range of motion) has a significant correlation with subjective patient-reported outcomes (OKS). Hence, both outcome measures should be employed in the postoperative monitoring of patient progress. LEVEL OF EVIDENCE: Prospective case series, Level IV.

Coronary artery calcification across ethnic groups in Singapore

<p><b>INTRODUCTION</b>In Singapore, the age-standardised event rates of myocardial infarction (MI) are 2- and 3-fold higher for Malays and Indians respectively compared to the Chinese. The objectives of this study were to determine the prevalence and quantity of coronary artery calcification (CAC) and non-calcified plaques across these 3 ethnic groups.</p><p><b>MATERIALS AND METHODS</b>This was a retrospective descriptive study. We identified 1041 patients (810 Chinese, 139 Malays, 92 Indians) without previous history of cardiovascular disease who underwent cardiac computed tomography for atypical chest pain evaluation. A cardiologist, who was blinded to the patients' clinical demographics, reviewed all scans. We retrospectively analysed all their case records.</p><p><b>RESULTS</b>Overall, Malays were most likely to be active smokers (P = 0.02), Indians had the highest prevalence of diabetes mellitus (P = 0.01) and Chinese had the highest mean age (P <0.0001). The overall prevalence of patients with non-calcified plaques as the only manifestation of sub-clinical coronary artery disease was 2.1%. There was no significant difference in the prevalence of CAC, mean CAC score or prevalence of non-calcified plaques among the 3 ethnic groups. Active smoking, age and hypertension were independent predictors of CAC. Non-calcified plaques were positively associated with male gender, age, dyslipidaemia and diabetes mellitus.</p><p><b>CONCLUSION</b>The higher MI rates in Malays and Indians in Singapore cannot be explained by any difference in CAC or non-calcified plaque. More research with prospective follow-up of larger patient populations is necessary to establish if ethnic-specific calibration of CAC measures is needed to adjust for differences among ethnic groups.</p>

Effectiveness of an algorithm in reducing the number of unnecessary ultrasound scans for deep vein thrombosis: an evaluation report

<p><b>INTRODUCTION</b>Patients with suspected deep vein thrombosis (DVT) pose a diagnostic dilemma to the Emergency Department (ED) clinician. This study aimed to implement a known algorithm incorporating the modified Wells criteria and D-dimer testing to guide the ED clinician, thus reducing unnecessary ultrasound scans (USS).</p><p><b>METHODS</b>Patients who presented to the ED between August 2008 and April 2009 with suspected DVT underwent Wells scoring. Those with scores < 2 were deemed unlikely to have DVT and underwent D-dimer testing first. Patients with scores ≥ 2 were regarded as likely to have DVT and underwent urgent USS. USS findings were tabulated as positive or negative/indeterminate for DVT. The latter group was followed up for one year to check whether DVT was missed during the initial USS.</p><p><b>RESULTS</b>75 patients presented with suspected DVT and underwent USS. Of these, 14 results were positive and 61 were negative. 37 patients had Wells scores < 2, with three (8.1%) having DVT. Another 38 patients had Wells scores ≥ 2, with 11 (28.9%) having DVT. D-dimer testing was performed on 27 of the 75 patients. Those with DVT had higher average values compared to those without DVT (1.305 vs. 0.595 µg/ml). The majority of patients with raised D-dimer values had cellulitis, although three also had DVT (with values ≥ 0.99 µg/ml).</p><p><b>CONCLUSION</b>We managed to reduce the number of unnecessary USS and increase the pick-up rate of DVT. A cut-off score ≥ 2 in our algorithm is suitable for use in the ED setting.</p>

The excess financial burden of multidrug resistance in severe gram-negative infections in Singaporean hospitals

<p><b>INTRODUCTION</b>Multidrug-resistant (MDR) Gram-negative healthcare-associated infections are prevalent in Singaporean hospitals. An accurate assessment of the socioeconomic impact of these infections is necessary in order to facilitate appropriate resource allocation, and to judge the costeffectiveness of targeted interventions.</p><p><b>MATERIALS AND METHODS</b>A retrospective cohort study involving inpatients with healthcare-associated Gram-negative bacteraemia at 2 large Singaporean hospitals was conducted to determine the hospitalisation costs attributed to multidrug resistance, and to elucidate factors affecting the financial impact of these infections. Data were obtained from hospital administrative, clinical and financial records, and analysed using a multivariate linear regression model.</p><p><b>RESULTS</b>There were 525 survivors of healthcare-associated Gram-negative bacteraemia in the study cohort, with 224 MDR cases. MDR bacteraemia, concomitant skin and soft tissue infection, higher APACHE II score, ICU stay, and appropriate definitive antibiotic therapy were independently associated with higher total hospitalisation costs, whereas higher Charlson comorbidity index and concomitant urinary tract infection were associated with lower costs. The excess hospitalisation costs attributed to MDR infection was $8638.58. In the study cohort, on average, 62.3% of the excess cost attributed to MDR infection was paid for by government subvention.</p><p><b>CONCLUSION</b>Multidrug resistance in healthcare-associated Gram-negative bacteraemia is associated with higher financial costs--a significant proportion of which are subsidised by public funding in the form of governmental subvention. More active interventions aimed at controlling antimicrobial resistance are warranted, and the results of our study also provide possible benchmarks against which the cost-effectiveness of such interventions can be assessed.</p>

Wash-out of hepatocellular carcinoma: quantitative region of interest analysis on CT

<p><b>INTRODUCTION</b>This study aims to determine if the quantitative method of region-of-interest (ROI) analysis of lesion attenuation on CT may be a useful adjunct to the conventional approach of diagnosis by visual assessment in assessing tracer wash-out in hepatocellular carcinomas.</p><p><b>MATERIALS AND METHODS</b>From a surgical database of 289 patients from 2 institutions, all patients with complete surgical, pathological and preoperative multiphasic CT scans available for review were selected. For each phase of scanning, HU readings of lesion obtained (Lesion(arterial), Lesion(PV) and Lesion(equilibrium)) were analysed using receiver operating curves (ROC) to determine the optimal method and cut-off value for quantitative assessment of tumour wash-out (Lesion(arterial - equilibrium), Lesion(PV - equilibrium) or Lesion(peak - equilibrium)).</p><p><b>RESULTS</b>Ninety-four patients with one lesion each met the inclusion criteria. The area under the curve (AUC) values for Lesion(arterial - equilibrium) (0.941) was higher than the AUC for Lesion(pv - equilibrium) (0.484) and for Lesion(peak - equilibrium) (0.667). Based on ROC analysis, a cut-off of 10HU value for Lesion(arterial - equilibrium) would yield sensitivity and specificity of 91.5% and 80.9%, respectively. ROI analysis detected 9/21 (42.9%) of lesions missed by visual analysis. Combined ROI and visual analysis yields a sensitivity of 82/94 (87.2%) compared to 73/94 (77.7%) for visual analysis alone.</p><p><b>CONCLUSION</b>Using a cut-off of 10 HU attenuation difference between the arterial and equilibrium phases is a simple and objective method that can be included as an adjunct to visual assessment to improve sensitivity for determining lesion wash-out on CT.</p>

Difference in Asthma Control Test™ (ACT) scores in three different clinical practice settings.

INTRODUCTION: Asthma control varies in different clinical settings because of its multidimensional and heterogeneous nature, and variability over time. The revised asthma management guidelines indicate that the goal of treatment should be maintaining asthma control for long periods. The aims of this study were to explore: (i) difference in asthma control test scores in patients at different clinical practice settings; (ii) assess if patients were overestimating the level of their asthma control and (iii) assess the relationship of the derived Asthma Control Test (ACT) score to cost of inpatient stay and length of stay (LOS). MATERIALS AND METHODS: The Asthma Control Test (ACT) is a 5-item questionnaire that assesses the multidimensional perspective of asthma control from activity limitation, shortness of breath, night symptoms, use of rescue medication and self-perception of asthma control. The score ranges on a scale from 1 (poorly controlled) to 5 (well controlled). ACT was administered to 447 patients diagnosed with asthma from the in-patient and out-patient settings (new and follow-up cases). RESULTS: Three hundred and ninety-nine (92%) patients completed the ACT questionnaire. The analysis only included patients who had completed the ACT questionnaire. The analysis showed that all the 5 items in the ACT questionnaire were significantly associated with different clinical settings (P <0.001). When we correlated the ACT question 5 (patients' self-rating of asthma control) in the ACT with Question 3 and Question 4 individually, it showed that most patients did not overestimate their asthma control (P <0.001). However, there was no correlation between the derived ACT score and cost (P = 0.419), LOS (P = 0.373), and the number of comorbid medical history (P = 0.055). CONCLUSION: Our results reinforce the usefulness of ACT for clinicians to identify patients with poorly controlled asthma and to optimise their level of control in different clinical settings.

Deep venous thrombosis in Asian traumatic brain injury patients during rehabilitation: prevalence and risk factors.

OBJECTIVES: To determine the prevalence and risk factors of asymptomatic lower-limb deep venous thrombosis (DVT) among Asians in inpatient rehabilitation after traumatic brain injury (TBI). DESIGN: a prospective observational study. PARTICIPANTS: Fifty-six (35 males and 21 females) Asian individuals with TBI with a median of 25 days to rehabilitation. The mean age was 49.3 +/- 20.4 years and 64.3% (36) were Chinese, 19.6% (11) were Malay, 10.7% (6) were Indian, and 5.4% (3) were of other races. MAIN MEASURES: quantitative D-dimer assay (DDA) and targeted hemiplegic/weaker lower extremity venous duplex ultrasonography (VDU) for patients with elevated DDA levels (>or=0.34 microg/mL). Outcome measures included the incidence of DVT based on VDU diagnosis. RESULTS: All 34 (60.7%) patients who had elevated DDA levels underwent single limb VDU, revealing an incidence of 5.4% (3) of lower-limb DVT, including 1 case of proximal and 2 of distal DVT. Logistic regression analyses did not reveal any significant predictive factors for DVT, but tracheostomy, higher admission Glasgow Coma Scale (GCS) score, and lower Functional Independence Measure (FIM)-walk scores correlated significantly with elevated DDA levels (P < .05). Receiver-operating characteristic analysis showed that cutoff DDA levels of 1.37 mg/mL resulted in a sensitivity of 100% and a specificity of 67.7%. CONCLUSION: Asymptomatic DVT is uncommon in Asian TBI rehabilitation patients. Our low incidence could be related to the small sample size, ethnic protective factors, early walking during rehabilitation, and timing of VDU during possible declining thrombotic risk.

Effect of enoxaparin on peak and trough levels of antifactor Xa in patients with a creatinine clearance of less than 30 mL/min.

AIM: To assess whether there was an increased risk of bleeding with enoxaparin in patients with a creatinine clearance (CCT) of less than 30 mL/min. METHODS: Patients with a CCT of less than 30 mL/min who were given enoxaparin 1 mg/kg/day were included. Antifactor Xa levels (peak and trough) were measured after three doses (days) of enoxaparin. The peak antifactor Xa levels were measured 4 h after the third enoxaparin dose, and the trough levels of antifactor Xa were measured 12 h and 24 h after the third enoxaparin dose. Basic demographic data such as age, sex, race, diagnosis and creatinine values were assessed at baseline. Adverse events were monitored and recorded. Domain-specific review board approval was obtained before the present study began. RESULTS: A total of 15 patients were recruited for the present study. Three patients dropped out of the study; therefore, 12 patients were analyzed. The mean age of the 12 patients was 69.25 years (range 41 to 89 years). There were six men and an equal number of women. There were eight Chinese patients, three Malay patients and one Indian patient. The indication for anticoagulation was deep vein thrombosis in seven patients, non-ST elevation myocardial infarction in four patients and atrial fibrillation in one patient. There were no adverse events noted in any patient. CONCLUSION: It is safe to administer enoxaparin once a day to patients with renal impairment and a CCT of less than 30 mL/min.

Was it easy to use an Asthma Control Test (ACT) in different clinical practice settings in a tertiary hospital in Singapore?

<p><b>INTRODUCTION</b>The Asthma Control Test (ACT) is a 5-item self-administered tool designed to assess asthma control. It is said to be simple, easy and can be administered quickly by patients in the clinical practice setting. This stated benefit has yet to be demonstrated in our local clinical practice setting. The aim was to identify factors associated with difficulty in the administration of the ACT in different clinical practice settings in a tertiary hospital in Singapore.</p><p><b>MATERIALS AND METHODS</b>This is a prospective study performed from April to June 2008. All patients diagnosed with asthma and referred to an asthma nurse from the in-patient and out-patient clinical practice setting in Tan Tock Seng Hospital were enrolled.</p><p><b>RESULTS</b>Four hundred and thirty-four patients were asked to complete the ACT tool. In the univariate model, we found that age, clinical setting and medical history to be significantly associated with the completion of the ACT. The odds of completion decreased by a factor of 0.92 (95% CI, 0.89 to 0.94) for every year's increase in age, and this was statistically significant (P <0.001). Similarly, the odds ratio of completion for those with more than 3 medical conditions by history were 0.59 (95% CI, 0.48 to 0.71) as compared to those with less than 3 medical conditions by history, and this was also significant (P <0.001). In the multivariate model, we only found age to be an independent and significant factor. After adjusting for age, none of the other variables initially significant in the univariate model remained significant.</p><p><b>CONCLUSION</b>The results show that the ACT was simple and easy to be administered in younger-aged patients.</p>

A prospective cohort study on the impact of a modified Basic Military Training (mBMT) programme based on pre-enlistment fitness stratification amongst Asian military enlistees

<p><b>INTRODUCTION</b>This study objectively evaluates the effectiveness of a 6-week Preparatory Training Phase (PTP) programme prior to Basic Military Training (BMT) for less physically conditioned conscripts in the Singapore Armed Forces.</p><p><b>MATERIALS AND METHODS</b>We compared exercise test results of a group of less fi t recruits who underwent a 16-week modified-BMT (mBMT) programme (consisting of a 6-week PTP and 10-week BMT phase) with their 'fitter' counterparts enlisted in the traditional 10-week direct-intake BMT (dBMT) programme in this prospective cohort study consisting of 36 subjects. The main outcome measures included cardiopulmonary responses parameters (VO(2)max and V(O2AT)) with clinical exercise testing and distance run timings.</p><p><b>RESULTS</b>Although starting off at a lower baseline in terms of physical fitness [VO(2)max 1.73 +/- 0.27 L/min (mBMT group) vs 1.97 +/- 0.43 L/min (dBMT), P = 0.032; V(O2AT) 1.02 +/- 0.19 vs 1.14 +/- 0.32 L/min respectively, P = 0.147], the mBMT group had greater improvement in cardiopulmonary indices and physical performance profiles than the dBMT cohort as determined by cardiopulmonary exercise testing [VO(2)max 2.34 +/- 0.24 (mBMT) vs 2.36 +/- 0.36 L/min (dBMT), P = 0.085; V(O2AT) 1.22 +/- 0.17 vs 1.21 +/- 0.24 L/min respectively, P = 0.303] and 2.4 kilometres timed-run [mBMT group 816.1 sec (pre-BMT) vs 611.1 sec (post-BMT), dBMT group 703.8 sec vs 577.7 sec, respectively; overall P value 0.613] at the end of the training period. Initial mean difference in fitness between mBMT and dBMT groups on enlistment was negated upon graduation from BMT.</p><p><b>CONCLUSION</b>Pre-enlistment fitness stratification with training modification in a progressive albeit longer BMT programme for less-conditioned conscripts appears efficacious when measured by resultant physical fitness.</p>

Detection of internal carotid artery stenosis with duplex velocity criteria using receiver operating characteristic analysis

<p><b>INTRODUCTION</b>Duplex 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.</p><p><b>MATERIALS AND METHODS</b>From 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.</p><p><b>RESULTS</b>Internal 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%).</p><p><b>CONCLUSION</b>Our study showed that velocity ratios are superior to other criteria for detecting carotid stenosis. Each laboratory needs to validate its own results.</p>

Seroepidemiology of pertussis in the adult population of Singapore

<p><b>INTRODUCTION</b>Pertussis is a highly communicable, vaccine-preventable respiratory disease and a frequent but often underestimated cause of prolonged cough illness in adults. Protection after childhood vaccination is minimal after 10 years without boosting. The need for adult booster depends on the national epidemiology.</p><p><b>MATERIALS AND METHODS</b>We did a seroepidemiological survey amongst the adult population (aged 18 to 45 years) of Singapore. None had received pertussis booster vaccine in the preceding 10 years. We measured IgG antibodies to pertussis whole cell antigen.</p><p><b>RESULTS</b>Two hundred and seventy subjects with the median age of 30 years were enrolled. We found positive IgG antibody levels in 97% of the population. Seropositivity was not associated with age, gender or race.</p><p><b>CONCLUSION</b>The seroprevalence in adults was much higher than the previously documented seroprevalence of around 50% in the adolescent age group in Singapore. The increase is most likely due to natural infection with B. pertussis. Pertussis booster vaccine for adolescents/young adults in Singapore would be indicated.</p>

SARS in Singapore--predictors of disease severity

<p><b>INTRODUCTION</b>Severe acute respiratory syndrome (SARS) affected 8096 individuals in 29 countries, with 774 deaths. In Singapore, there were 238 cases of SARS with 33 deaths. A retrospective analysis was performed to identify predictors of poor outcome in patients with SARS locally.</p><p><b>MATERIALS AND METHODS</b>Clinical, laboratory and outcome data of 234 patients admitted to Tan Tock Seng Hospital and Singapore General Hospital were collected and analysed. Only data collected at the time of admission were used in the analysis for predictors of poor outcome. Adverse events were defined as admission to the intensive care unit or death.</p><p><b>RESULTS</b>Clinical (temperature, FiO2) and laboratory [leukocyte, lymphocyte, neutrophil, platelet, lactate dehydrogenase (LDH), albumin] trends in groups with and without an adversarial event were presented. Fifty patients experienced an adverse event. On univariate analysis, male gender, advanced age, presence of comorbidities, neutrophilia, lymphopaenia, hyponatraemia, hypoalbuminaemia, transaminitis and elevated LDH or C-reactive protein were found to be significant predictors. On multivariate analysis, predictors of poor outcome were increased age [odds ratio (OR) 1.73 for every 10-year increase; 95% CI, 1.35 to 2.21], neutrophilia (OR 1.06 for every 1 x 10(9)/L increase; 95% CI, 1.02 to 1.11) and high LDH (OR 1.17 for every 100 U/L increase; 95% CI, 1.02 to 1.34). None of the 12 paediatric patients had an adverse event.</p><p><b>CONCLUSION</b>Advanced age, neutrophilia and high LDH predict poor outcomes in patients with SARS.</p>

Evaluation of dementia: the case for neuroimaging all mild to moderate cases

<p><b>INTRODUCTION</b>The aim of this study was to assess the usefulness of 4 clinical prediction rules, the neuroimaging guidelines from the Canadian Consensus Conference on Dementia (CCCAD) and the modified Hachinski's Ischaemic Score (HIS) in identifying patients with suspected dementia who will benefit from neuroimaging.</p><p><b>MATERIALS AND METHODS</b>Two hundred and ten consecutive patients were referred to the memory clinic in a geriatric unit for the evaluation of possible dementia. Sensitivity, specificity and likelihood ratios (LR) were calculated for each of the prediction rules and the CCCAD guidelines, in terms of their ability to identify patients with significant lesions [defined firstly as space-occupying lesions (SOL) alone and secondly as SOL or strokes] on neuroimaging. Similar analyses were applied for the HIS in the detection of strokes.</p><p><b>RESULTS</b>When considering SOL alone, sensitivities ranged from 28.6% to 100% and specificities ranged from 21.7% to 88.4%. However, when strokes were included in the definition of significant lesions, sensitivities ranged from 16.2% to 79.0% and specificities ranged from 20.9% to 92.4%. The modified HIS had a similarly poor sensitivity and specificity (43.3% and 78.9% respectively). The LR for the clinical decision tools did not support the use of any particular instrument.</p><p><b>CONCLUSIONS</b>Clinical decision tools do not give satisfactory guidance for determining the need for neuroimaging patients with suspected dementia, when the detection of strokes, in addition to SOL, is regarded as important. We recommend therefore that neuroimaging be considered for all patients with suspected mild or moderate dementia in whom the potential benefits of any treatment outweigh the potential risks.</p>

Comparison of magnetic resonance spectroscopy and perfusion-weighted imaging in presurgical grading of oligodendroglial tumors.

OBJECTIVE: Oligodendroglial tumors form an uncommon, but distinct, subgroup of gliomas with longer survival, better treatment response, and characteristic genetic alterations. Noninvasive grading of oligodendroglial tumors using functional and metabolic magnetic resonance imaging may be helpful in guiding the treatment approach and predicting malignant transformation of these tumors. We used perfusion-weighted magnetic resonance imaging and proton magnetic resonance spectroscopic imaging (MRSI) to predict the oligodendroglioma grade. METHODS: Twenty-four patients with pathologically confirmed oligodendrogliomas underwent dynamic contrast-enhanced perfusion-weighted magnetic resonance imaging and/or proton MRSI before surgery. We assessed the ability of tumor contrast enhancement, normalized cerebral blood volume, normalized choline, and the presence of either lactate or lipid metabolites to correctly predict the World Health Organization tumor grade. The accuracy of tumor grading using each method was also compared. RESULTS: Tumor contrast enhancement (P = 0.069) and normalized cerebral blood volume (P = 0.181) were not significantly different between low and high-grade oligodendrogliomas. The MRSI measurement of normalized choline was significantly higher in high-grade (2.82 +/- 0.64) than in low-grade (1.62 +/- 0.46) oligodendrogliomas (P < 0.001), and the presence of lactate or lipid metabolites also correctly predicted high-grade tumors (P = 0.014). The maximum accuracy of contrast enhancement, normalized cerebral blood volume, normalized choline, and lactate or lipid metabolites in grading oligodendroglioma was 71, 83, 90, and 85%, respectively. CONCLUSION: MRSI measurements are more accurate than perfusion-weighted magnetic resonance imaging or conventional contrast enhancement in differentiating oligodendroglial tumor grade. In these inherently vascular tumors, metabolic measurements of mitosis and necrosis may be better than measures of neovascularity in presurgical grading.