Functional outcome after selective dorsal rhizotomy: a retrospective case control study.

PURPOSE: This study examines long-term benefit on functional outcomes and quality of life after selective dorsal rhizotomy (SDR) in children with spastic diplegia in Hong Kong. METHOD: This is a case control study. Individuals with spastic diplegia who were at 6 to 12 years post-SDR were recruited. Age, gender, cognition, and Gross Motor Function Classification System level-matched individuals with spastic diplegia who had not undergone SDR were recruited as controls. Outcome measures included physical level, functional level, physiological level, and quality of life. All data were compared by independent t-test. RESULTS: Individuals post-SDR (n = 15) demonstrated a significantly better range of ankle dorsiflexion in knee extension by - 5.7 ± 10.9° than the control group (n = 12). No other significant differences were observed. CONCLUSION: SDR is a safe, one-off procedure and provides long-term reduction in spasticity with no major complications. With the heterogeneity, we did not demonstrate between-group differences in long-term functional outcomes.

Establishment of CT diagnostic reference levels (DRLs) for a Singapore healthcare cluster.

INTRODUCTION: The use of computed tomography (CT) in healthcare institutions has increased rapidly in recent years. The Singapore Health Services (SingHealth) cluster of healthcare institutions has taken the first step in establishing a local cluster-wide CT Diagnostic Reference Levels (DRL) in Singapore. CT dose data from each institution were collected through two primary dosimetry metrics: volume CT dose index (CTDIvol measured in mGy) and dose-length product (DLP measured in mGy.cm). METHODS: Data from 19 CT scanners in seven institutions under one of Singapore healthcare cluster were retrospectively collected and analysed. The five common adult CT examinations analysed were CT Brain (non-contrast enhanced), CT Chest (IV contrast enhanced), CT Kidney-Ureter-Bladder (CT KUB, non-contrast enhanced), CT Pulmonary Angiogram (CT PA, IV contrast enhanced) and CT Abdomen-Pelvis (CT AP, IV contrast enhanced, single phase). Median CTDIvol and DLP values for the five CT examinations from each institution were derived, with the cluster DRLs determined as the 75th percentile of the distribution of the institution median dose values. RESULTS: A total of 2413 dose data points were collected over a six-month period from June to November 2020. The cluster CT DRLs for the five CT examinations were determined to be 47 mGy and 820 mGy.cm for CT Brain, 5.4 mGy and 225 mGy.cm for CT Chest, 6.7 mGy and 248 mGy.cm for CT PA, 4.6 mGy and 190 mGy.cm for CT KUB and 6.9 mGy and 349 mGy.cm for CT AP. CONCLUSION: The establishment of the cluster CT DRLs provided individual institutions with a better understanding if their CT doses are unusually high or low, while emphasising that these DRLs are not meant as hard dose limits or constraints to follow strictly.

Failure of sterilization in a dental outpatient facility: Investigation, risk assessment, and management.

In 2017, an incident of failed sterilization of dental instruments occurred at a large dental outpatient facility in Singapore. We aim to describe findings of the investigation of the sterilization breach incident, factors related to risk of viral transmission to the potentially affected patients, and the contact tracing process, patient management, and blood test results at a 6-month follow-up. A full assessment of the incident was immediately carried out. The factors related to risk of viral transmission due to affected instruments were analyzed using 3 keys points: breached step(s) and scale of the incident, prevalence of underlying bloodborne diseases and immunity in the Singapore population, health status of potential source patients, and type of dental procedure performed, and health status of affected patients and type of dental procedure received. Up to 72 affected instrument sets were used in 714 potentially affected patients who underwent noninvasive dental procedures. The investigation revealed that there was a lapse in the final step of steam sterilization, resulting in the use of incompletely sterilized items. The assessment determined that there was an extremely low risk of bloodborne virus transmission of diseases to the patients. At the 6-month follow-up, there were no infected/colonized cases found related to the incident. Lapses in the sterilization process for medical and dental instruments can happen, but a risk assessment approach is useful to manage similar incidents. Quick response and proper documentation of the sterilization process can prevent similar incidents.

Peri-operative management of patients with Parkinson's disease.

Patients with Parkinson's disease are at higher risk of peri-operative medical and surgical complications. Multidisciplinary management, early recognition of potential complications, specialised care of medications and intra-operative protection of the vulnerable brain are all important aspects of the peri-operative management of patients with Parkinson's disease. Advances in continuous dopaminergic treatment, development of a peri-operative Parkinson's disease pathway and application of telemedicine are starting to play a role in improving peri-operative care. Management of patients with advanced Parkinson's disease is also evolving, with potential for incorporation of integrated care and changes in the anaesthetic management for deep brain stimulation surgery. There are new methods for localisation of target nuclei and increasing insight on the effects of anaesthetic drugs on microelectrode recordings and clinical outcomes. Parkinson's disease is a progressive disease, but management is improving with better peri-operative care for patients.

Peri-operative neurological monitoring with electroencephalography and cerebral oximetry: a narrative review.

Surgery and anaesthesia subject the brain to considerable stress in the peri-operative period. This may be caused by potentially neurotoxic anaesthetic drugs, impaired cerebral perfusion and reperfusion injury related to surgery or thromboembolic events. Patient monitoring using electroencephalogram and cerebral oximetry can assist in optimising depth of anaesthesia and assessment of cerebral metabolic activity. However, research findings have been contradictory as to whether these monitors can help ameliorate peri-operative neurocognitive complications. In this narrative review, we will discuss recent evidence in the use of electroencephalography and cerebral oximetry and the underlying scientific principles. It is important to appreciate the raw electroencephalographic changes under anaesthesia and those associated with ageing, in order to interpret depth of anaesthesia indices correctly. Cerebral oximetry is useful not only for the detection of cerebral desaturation but also to identify those patients who are particularly vulnerable to injury, for better risk stratification. An algorithm-based approach may be most effective in managing the episodes of cerebral desaturation.

Breast Implant-associated Anaplastic Large Cell Lymphoma - a Systematic Review with Pooled Analysis.

The association of breast implants and anaplastic large cell lymphoma (BIA-ALCL) was first described in 1997. Such an association has aroused public health concerns on breast implant safety. A systematic review was carried out with a pooled analysis of data. In total, 674 non-duplicate articles were retrieved; 77 articles were included for data extraction; 395 patients were identified for analysis. The median age at the time of diagnosis was 52 years. Implant texture was described in 201 (50.9%) patients; all 201 patients had a textured implant. The median time from the last implant insertion to diagnosis was 7.5 years. Most patients presented with seroma (67.1%, n = 265), 20.5% of patients presented with breast mass (n = 81). Patients with a breast mass at presentation, lymphadenopathy and those without seroma had more disseminated disease (P < 0.001). 73.2% of patients (n = 289) opted for primary surgery, among which 68.6% (n = 271) received removal of the implant, 61% (n = 241) received capsulectomy and 2% (n = 8) received mastectomy. Of note, 5.3% (n = 21) had reinsertion of an implant after primary surgery. Non-surgical modalities included chemotherapy, radiotherapy and haematopoietic stem cell transplant. The median follow-up interval was 2 years (range 0-14.5 years). Seventeen patients (4.3%) had recurrence of BIA-ALCL and 195 patients (49.4%) did not. The median duration to first recurrence was 1 year (range 1-3 years). Long-term clinical outcome was not reported in 183 patients. BIA-ALCL is an indolent disease that presents with seroma after implant insertion. A high index of suspicion is needed for early diagnosis and treatment.

Factors associated with common and atypical chromosome abnormalities after positive combined first-trimester screening in Chinese women: a retrospective cohort study.

BACKGROUND: When cell-free DNA (cfDNA) testing is used as a secondary screening tool following combined first-trimester screening (cFTS), cFTS is used to estimate the prior risk for chromosome abnormalities. This study aimed to assess the factors that are associated with common and atypical abnormalities following cFTS, including cFTS risk, advanced maternal age, increased nuchal translucency (NT) ≥3.5 mm, and abnormal levels of serum markers. METHODS: We reviewed a historical cohort of 1855 Chinese women carrying singleton pregnancies with a positive cFTS [at a threshold of 1:250 for trisomy (T) 21 or 1:180 for T18] in one public hospital over a five-year period. All chromosome abnormalities were confirmed by invasive prenatal diagnosis (IPD) with karyotyping, with or without array comparative genomic hybridization. Using multivariable binary logistic regression analysis, we determined the parameters that were associated with common and atypical abnormalities. RESULTS: Overall, the prevalence of common and atypical abnormalities was 6.2 and 1.2%, respectively, and the prevalence increased with the risk of T21 by cFTS. In pregnancies with a risk of T21 > 1 in 100, a high risk of both T21 and T18, an increased NT, or a pregnancy-associated plasma A (PAPP-A) level <  0.2 multiple of medians (MoM), the prevalence of common abnormalities was 12.2, 64.7, 25.5 and 33.8%, respectively, while that of atypical abnormalities was 1.6, 3.9, 4.2, and 7.4%, respectively. In the multivariable binary logistic regression analysis, out of these four factors, only two (increased NT and PAPP_A <  0.2 MoM) were significant predictors of common and atypical abnormalities, respectively. Of all positive cFTS pregnancies, 50.4% did not have any of these four factors, and the prevalence of common and atypical abnormalities was 1.1 and 0.6%, respectively. There were three atypical abnormalities, all of which were mosaicism, and they were detected among women with IPD alone. The ages of these women were ≥ 35 years. All three pregnancies were continued after proper counseling. After giving birth, only one child had mild abnormalities, while the other two were phenotypically normal. CONCLUSIONS: Our study identified factors associated with common and atypical abnormalities after cFTS. These factors can be used to estimate the prior risk for these abnormalities to help with post-cFTS counseling in terms of choosing between cfDNA testing and IPD.

Management decision of hospital surge: assessing seasonal upsurge in inpatient medical bed occupancy rate among public acute hospitals in Hong Kong.

BACKGROUND: There were recurrent upsurges in demand for public hospital services in Hong Kong. An understanding of the contribution of some possible factors for the rise in health care burden would help to inform hospital management strategies. AIM: To evaluate the utilization patterns of hospitalizations in medical wards among public acute hospitals in Hong Kong during surge periods. DESIGN: Retrospective study. METHODS: By extracting the information in press releases between 2014 and 2018, descriptive statistics about medical ward occupancy situation during six surge periods were generated. A time series model was constructed to estimate the occupancy rate at each hospital and assess its relationship with the intensity of seasonal influenza activity, extreme weather, day of week and long holidays. RESULTS: There was a significant increase in the number of admissions to medical wards in all six surge periods. A significant variation in occupancy rate between weekdays and geographic regions was observed. The occupancy rate in 10, out of 15, hospitals was significantly associated with the influenza activity, while there was limited effect of weather on the occupancy rate. A significant holiday effect was observed during Christmas and Chinese New Year, resulting in a lower bed occupancy rate. CONCLUSIONS: A differential burden in public hospitals during surge periods was reported. Contingency bed and staff management shall be tailored to individual hospitals, given their differences in the determinants for inpatient bed occupancy.

Benefits and limitations of implementing Chronic Care Model (CCM) in primary care programs: A systematic review.

BACKGROUND: Chronic Care Model (CCM) has been developed to improve patients' health care by restructuring health systems in a multidimensional manner. This systematic review aims to summarize and analyse programs specifically designed and conducted for the fulfilment of multiple CCM components. We have focused on programs targeting diabetes mellitus, hypertension and cardiovascular disease. METHOD AND RESULTS: This review was based on a comprehensive literature search of articles in the PubMed database that reported clinical outcomes. We included a total of 25 eligible articles. Evidence of improvement in medical outcomes and the compliance of patients with medical treatment were reported in 18 and 14 studies, respectively. Two studies demonstrated a reduction of the medical burden in terms of health service utilization, and another two studies reported the effectiveness of the programs in reducing the risk of heart failure and other cardiovascular diseases. However, CCMs were still restricted by limited academic robustness and social constraints when they were implemented in primary care. Higher professional recognition, tighter system collaborations and increased financial support may be necessary to overcome the limitations of, and barriers to CCM implementation. CONCLUSION: This review has identified the benefits of implementing CCM, and recommended suggestions for the future development of CCM.

Danshen (Salvia miltiorrhiza) protects ovariectomized rats fed with high-saturated fat-sucrose diet from bone loss.

Dietary patterns may interfere with the efficacy of herbal intervention. Our results demonstrated the protective effects of Salvia miltiorrhiza aqueous extract (SMA) on bone metabolism were influenced by levels of dietary fat and sucrose in ovariectomized (OVX) rats through its actions on attenuating lipid deposition and oxidative stress in rats. INTRODUCTION: Salvia miltiorrhiza (SM), also known as Danshen, has been tested as an osteoporosis treatment in a series of small, short human trials that generally report improvements in bone property. However, dietary patterns may interfere with the effects of herbal intervention. We hypothesized that dietary fat and sucrose levels could influence the effects of SM supplementation on bone in estrogen-deficient animals. METHODS: Six-month-old Sprague-Dawley sham or OVX rats were fed either a low-saturated fat-sucrose (LFS, a diet that was similar in composition to normal rat chow) or a high-fat-sucrose (HFS) diet and OVX rats were treated (8 rats/group) with SM aqueous extract (SMA, 600 mg/kg/day), 17ß-estradiol (1 mg/kg/day), or vehicle for 12 weeks. RESULTS: SMA significantly improved bone properties as revealed by the increase in trabecular bone mineral density and decrease in trabecular separation at proximal metaphysis of the tibia (PT) in HFS-fed OVX rats, but not in LFS-fed OVX rats. SMA greatly reduced lipid deposition and malondialdehyde levels, improved the activities of superoxide dismutase, catalase, and glutathione peroxidase in the livers of HFS-fed OVX rats. SMA could directly improve the proliferation and differentiation in vitro in an H2O2-induced preosteoblast cell model by attenuating cellular reactive oxygen species levels. CONCLUSIONS: The protective effects of SMA on bone metabolism were influenced by dietary fat and sucrose levels in OVX rats. The ability of SMA to reduce bone loss in HFS-fed OVX rats was associated with the attenuation of lipid deposition and oxidative stress levels.

Standing balance post total knee arthroplasty: sensitivity to change analysis from four to twelve weeks in 466 patients.

OBJECTIVE: Little is known about how static standing balance changes post total knee arthroplasty (TKA). The primary aim of this study was to examine the sensitivity to change and redundancy of center of pressure (COP) variables post-TKA. The secondary aim was to compare the sensitivity of these measures to standard clinical assessments of one repetition maximum knee extension strength and fast pace gait speed. DESIGN: 466 participants performed instrumented double-limb standing balance tests with eyes open at 4 and 12 weeks post-TKA. Measures of COP standard deviation, amplitude, root mean square (RMS), path length, detrended fluctuation analysis (DFA) and signal frequency content for the medial-lateral (ML) and anterior-posterior (AP) axes were examined. RESULTS: Significant decreases in total path length, ML variables related to sway velocity and AP signal complexity and frequency were observed. Inter-session Cohen's d effect size (ES) revealed the strongest effect was for high velocity ML path length, with a 12% decrease in this rapid sway. This variable, along with AP mean instantaneous frequency and AP DFA, were the only ones significantly different with effect sizes >0.20 and non-redundant (Spearman's rho <0.75). The ES of COP-derived variables (maximum = 0.45) were lower than gait speed (1.40) and knee extensor strength (1.54). CONCLUSION: Increased high velocity ML sway is present at four compared to 12 weeks post-TKA. This augmented rapid sway may provide increased challenges to the postural control system at a time coinciding with reduced strength levels, which could have implications for physical function during activities of daily living.

Prenatal ultrasound monitoring of homozygous α0-thalassemia-induced fetal anemia.

A noninvasive approach by serial ultrasound examination at 12-15, 18, and 30 weeks of gestation can be used to exclude homozygous α0-thalassemia-induced fetal anemia. At 12-15 weeks of gestation, the predictive values for the fetal cardio-thoracic ratio were better than that for the placental thickness. At 16-20 weeks of gestation, measuring middle cerebral artery peak systolic velocity is associated with a low false-positive rate. However, the false-positive rate of this noninvasive approach can be about 3%, requiring an invasive test to confirm the diagnosis. A false-negative may result in a delay in diagnosis. The success of this noninvasive approach depends on an accurate measurement of the fetal cardiothoracic ratio which can be improved by adequate training and subsequent quality control. Currently, there is a lack of data reporting the performance of a noninvasive approach before 12 weeks of gestation.

Association between rehabilitation attendance and physical function following discharge after total knee arthroplasty: prospective cohort study.

BACKGROUND: Rehabilitation is widely advocated and provided as a standard of care for patients with total knee arthroplasty (TKA) but its effects on intermediate- to longer-term physical function is unclear. Also unknown is the relationship between the number of rehabilitation sessions attended and functional outcomes. METHODS: We conducted a prospective cohort study of 1540 patients who had undergone TKA and were referred for rehabilitation. Physical function was indexed by the Short-Form 36 (SF-36) physical function score at 6 months post-TKA. We used multivariable linear regression to assess the association between rehabilitation attendance and Month-6 physical function. Among patients who attended rehabilitation, multivariable linear regression was used to examine the dose-response association between the number of sessions attended and Month-6 physical function. RESULTS: Of the 1540 patients, 68 patients did not attend rehabilitation, 86 patients attended one session, and 1386 patients attended two or more sessions. Adjusted for the propensity to attend rehabilitation, rehabilitation attendance was independently associated with better Month-6 SF-36 physical function (point estimate, 5.0 points; 95% CI, 0.5-9.5; P = 0.028 compared with patients with no rehabilitation). Among patients who attended rehabilitation, attending five sessions was associated with a 3.6-point increase in SF-36 scores (95% CI, 0.8-6.5; P = 0.01) relative to patients who attended one session. CONCLUSIONS: Rehabilitation attendance post-TKA is associated with an increase in self-report physical function. Among patients who attended rehabilitation, a modest dose-response relationship was observed between the number of sessions and functional outcomes.

Intraoperative neuromonitoring in major vascular surgery.

There has been a growing interest in using intraoperative neuromonitoring to reduce the incidence of stroke and paralysis in major vascular interventions. Electroencephalography, various neurophysiological evoked potential measurements, transcranial Doppler, and near-infrared spectroscopy are some of the modalities currently used to detect neural injuries. A good understanding of these modalities and their interactions with anaesthesia is important to maximize their value and to allow meaningful interpretation of their results. In view of the inter-individual differences in anatomy, physiological reserves, and severity of pathological processes, neuromonitoring may be a valuable method to evaluate the well-being of the nervous system during and after surgical interventions. In this review, we summarize some of their applications, efficacies, and drawbacks in major carotid and aortic surgeries.

Effect of non-invasive prenatal testing as a contingent approach on the indications for invasive prenatal diagnosis and prenatal detection rate of Down's syndrome.

INTRODUCTION: In Hong Kong, universal combined first-trimester screening for Down's syndrome was started as a 'free service' in July 2010. Non-invasive prenatal testing was available as a self-financed item in August 2011. This study aimed to determine whether the introduction of non-invasive prenatal testing as a contingent approach influenced the indications for invasive prenatal diagnosis and the consequent prenatal detection of Down's syndrome. METHODS: This historical cohort study was conducted at the Prenatal Diagnosis Clinic of Queen Elizabeth Hospital in Hong Kong. We compared the indications for invasive prenatal diagnosis and prenatal detection of Down's syndrome in singleton pregnancies 1 year before and 2 years following the availability of non-invasive prenatal testing as a contingent test after a positive aneuploidy test. All pregnant women who attended our hospital for counselling about universal Down's syndrome screening between August 2010 and July 2013 were recruited. RESULTS: A total of 16 098 women were counselled. After the introduction of non-invasive prenatal testing, the invasive prenatal diagnosis rate for a positive aneuploidy screening reduced from 77.7% in 2010-11 to 68.8% in 2012-13. The new combined conventional plus non-invasive prenatal testing strategy was associated with a lower false-positive rate (6.9% in 2010-11 vs 5.2% in 2011-12 and 4.9% in 2012-13). There was no significant increase in invasive prenatal diagnosis for structural anomalies over the years. There was no significant trend in the overall prenatal detection rate of Down's syndrome (100% 1 year before vs 89.1% 2 years after introduction of non-invasive prenatal testing). Four (2.6%) of 156 women who underwent non-invasive prenatal testing for a screen-positive result had a high-risk result for trisomy 21, which was subsequently confirmed by invasive prenatal diagnosis. There were no false-negative cases. CONCLUSION: The introduction of non-invasive prenatal testing as a contingent approach reduced the invasive prenatal diagnosis rate for a positive aneuploidy screening without affecting the invasive prenatal diagnosis rate for structural anomalies or the overall detection rate of fetal Down's syndrome.

Colorectal endoscopic submucosal dissection at a low-volume centre: tips and tricks, and learning curve in a district hospital in Hong Kong.

INTRODUCTION: Colorectal endoscopic submucosal dissection is not a widely adopted procedure due to its technical difficulties. This study aimed to share the experience in setting up this novel procedure and to report the learning curve for such a procedure at a low-volume district hospital in Hong Kong. METHODS: This case series comprised 71 colorectal endoscopic submucosal dissections that were performed by a single endoscopist without experience in gastric or colorectal endoscopic submucosal dissection. Lesion characteristics, procedure time per unit area of tumour, en-bloc resection rate, R0 resection rate, complications, and length of stay were recorded prospectively. Results were compared for two consecutive periods to study the learning curve. RESULTS: Overall, 41 (57.7%) tumours were located in the right colon, 21 (29.6%) in the left colon, and nine (12.7%) in the rectum. The median tumour area was 4 cm(2) (range, 0.25-16 cm(2)). The median operating time was 105 (range, 47-342) minutes. The median procedure time per unit area of tumour was 24.9 min/cm(2). There was one instance of intra-operative bleeding that required conversion to laparoscopic colectomy. There was no postoperative haemorrhage. The overall perforation rate was 15.5%, in which one required conversion to laparoscopic colectomy. The overall morbidity rate was 16.9% and there was no mortality. The median hospital stay was 1 day (range, 0-11 days). The overall en-bloc resection rate and R0 resection rate was 81.2% and 58.0%, respectively. Comparison of the two study periods revealed that procedure time per unit area of tumour decreased significantly from 31.5 min/cm(2) to 21.5 min/cm(2) (P=0.032). The en-bloc resection rate improved from 78.8% to 83.3% (P=0.15). The R0 resection rate improved significantly from 39.4% to 75.0% (P<0.01). CONCLUSION: Untutored colorectal endoscopic submucosal dissection is feasible with acceptable clinical outcomes at a low-volume district hospital in Hong Kong.

An Unusual Hydrops Fetalis Associated with Compound Heterozygosity for Krüppel-like Factor 1 mutations.

Hydrops fetalis is commonly due to Hb Bart's (γ4) disease in South East Asia. Here, we report an unusual case of hydrops fetalis due to congenital dyserythropoietic anemia (CDA) associated with compound heterozygosity for Krüppel-like factor 1 (KLF1) gene mutations. Fetal cardiomegaly was first detected on routine mid-trimester scan in a pregnant woman with normal mean corpuscular volume (MCV) and Rhesus positive status. The fetus subsequently developed hydrops fetalis, and cordocentesis showed severe fetal anemia with a hemoglobin (Hb) level of 3.4 g/dL. Common causes of fetal anemia including Hb Bart's disease, parvovirus infection, and red cell antibodies were excluded. In view of the marked increase in erythroblasts at various stages of erythropoiesis, the diagnosis of CDA was suspected. We screened the couple for previously reported KLF1 gene mutations, showing that the mother was heterozygous for the c.525_526insCGGCGCC, p.Gly176Argfs*179 mutation, and her husband heterozygous for c.1012C>A, p.Pro338Thr mutation. The fetus was a compound heterozygote for these two KLF1 mutations. After counseling, repeated intrauterine transfusions were given at 27, 29, and 34 weeks' gestation; the hydrops fetalis was resolved. The baby was delivered at 34 weeks' gestation and required monthly blood transfusions but was otherwise thriving. Bone marrow aspiration at 10 months of age showed the features of ineffective erythropoiesis, compatible with CDA. In conclusion, hydrops fetalis can rarely be due to CDA associated with a compound heterozygous mutation for KLF1 gene mutations, and be managed by repeated intrauterine transfusions. Our present report adds to the wide clinical spectrum of KLF1 mutations.